180 results on '"Michael A. Seidman"'
Search Results
2. Guided Meditation (Hypnosis) and Whole Person Health
- Author
-
Robert A, Levine, Charlene S, Levine, and Michael D, Seidman
- Subjects
Meditation ,Otorhinolaryngology ,Humans ,General Medicine ,Hypnosis - Abstract
Whole person (holistic) health deals with the mind-body-spirit connection as a unified domain. Balancing the whole person's health makes it possible for cells, tissues, and fluids that are out of balance in disease to come back into balance as the person heals from illness. The Automatic Pattern Recognition and Interruption system can facilitate rapid change in people, once they are freed up from subconscious mind constraints. The goal of the modern, transformed health-care system should be to combine the best of conventional care and whole person health to produce the best health care on the planet.
- Published
- 2022
3. Endocannabinoid System and the Otolaryngologist
- Author
-
Brandon Tapasak, Luke Edelmayer, and Michael D. Seidman
- Subjects
Otorhinolaryngology ,Cannabinoids ,Otolaryngologists ,Humans ,General Medicine ,Endocannabinoids - Abstract
The endocannabinoid system is located throughout the central and peripheral nervous systems, endocrine system, gastrointestinal system, and within inflammatory cells. The use of medical cannabinoids has been gaining traction as a viable treatment option for varying illnesses in recent years. Research is ongoing looking at the effect of cannabinoids for treatment of common otolaryngologic pathologies. This article identifies common otolaryngologic pathologies where cannabinoids may have benefit, discusses potential drawbacks to cannabinoid use, and suggests future directions for research in the application of medical cannabinoids.
- Published
- 2022
4. The Role of Machine Learning in Cardiovascular Pathology
- Author
-
David Dov, William R. Jeck, Kyle Lafata, Colin L. Cooke, Jeffrey I. Everitt, Carolyn Glass, Roarke Horstmeyer, Matthew Glass, and Michael A. Seidman
- Subjects
Pathology, Clinical ,Cardiovascular pathology ,Standardization ,business.industry ,media_common.quotation_subject ,Cardiology ,Machine learning ,computer.software_genre ,Machine Learning ,Clinical Practice ,Cardiovascular Diseases ,Image Processing, Computer-Assisted ,Animals ,Humans ,Medicine ,Quality (business) ,Artificial intelligence ,Medical diagnosis ,Cardiology and Cardiovascular Medicine ,business ,Drug toxicity ,computer ,Algorithms ,Heart allograft ,media_common - Abstract
Machine learning has seen slow but steady uptake in diagnostic pathology over the past decade to assess digital whole slide images. Machine learning tools have incredible potential to standardize, and likely even improve, histopathologic diagnoses, but they are not yet widely used in clinical practice. We describe here the principles of these tools and technologies and some successful pre-clinical and pre-translational efforts in cardiovascular pathology, as well as a roadmap for moving forward. In animal models, one proof-of-principle application is in rodent progressive cardiomyopathy, of particular significance to drug toxicity studies. Basic science successes include screening the quality of differentiated stem cells and characterizing cardiomyocyte developmental stages, with potential applications for research and toxicology/drug safety screening using derived or native human pluripotent stem cells differentiated into cardiomyocytes. Translational studies of particular note include those with success in diagnosing the various forms of heart allograft rejection. In fully realizing the value of these tools in clinical cardiovascular pathology, we have identified three essential challenges. First is image quality standardization to ensure that algorithms can be developed and implemented on robust, consistent data. The second is consensus diagnosis; experts don't always agree, and thus "truth" may be difficult to establish, but the algorithms themselves may provide a solution. The third is the need for large enough data sets to facilitate robust algorithm development, necessitating large, cross-institutional, shared image databases. The power of histopathology-based machine learning technologies is tremendous; we outline here the next steps needed to capitalize on this power.
- Published
- 2022
5. Natural Alternatives and the Common Cold and Influenza
- Author
-
Varun S. Patel and Michael D. Seidman
- Subjects
Complementary Therapies ,Integrative Medicine ,Otorhinolaryngology ,Dietary Supplements ,Influenza, Human ,Common Cold ,Humans ,General Medicine ,United States - Abstract
The use of complementary and integrative medicine has increased . It is estimated that one-third of the population of the United States uses some form of alternative medicine. Physicians should consider integrative medicine therapies . Alternative medical therapies for the common cold and influenza include herbal supplements, dietary supplements, diet, and other adjunct therapies. However, it is important to research and study these therapies. Therefore, communication with patients and other health care providers is important. This will ensure effective and positive patient care experiences. Further randomized clinical trials are necessary to further establish the role of various alternative options.
- Published
- 2022
6. Can Electrocochleography Help Preserve Hearing After Cochlear Implantation With Full Electrode Insertion?
- Author
-
Michael S. Harris, Kanth Koka, William J. Riggs, Shaza Saleh, Jourdan T. Holder, Robert T. Dwyer, Sandra Prentiss, Shannon Lefler, Kristin Kozlowski, Megan M. Hiss, Amanda J. Ortmann, Erin Nelson-Bakkum, Andreas Büchner, Rolf Salcher, Steven A. Harvey, Michael E. Hoffer, Jorge E. Bohorquez, Farid Alzhrani, Rana Alshihri, Almuhawas Fida, Christopher J. Danner, David R. Friedland, Michael D. Seidman, Thomas Lenarz, Fred F. Telischi, Robert F. Labadie, Craig A. Buchman, and Oliver F. Adunka
- Subjects
Adult ,Cochlear Implants ,Otorhinolaryngology ,Hearing ,Humans ,Neurology (clinical) ,Prospective Studies ,Cochlear Implantation ,Sensory Systems ,Audiometry, Evoked Response ,Cochlea - Abstract
To evaluate the utility of intracochlear electrocochleography (ECochG) monitoring during cochlear implant (CI) surgery on postoperative hearing preservation.Prospective, randomized clinical trial.Ten high-volume, tertiary care CI centers.Adult patients with sensorineural hearing loss meeting the CI criteria who selected an Advanced Bionics CI.Patients were randomized to CI surgery either with audible ECochG monitoring available to the surgeon during electrode insertion or without ECochG monitoring. Hearing preservation was determined by comparing preoperative unaided low-frequency (125-, 250-, and 500-Hz) pure-tone average (LF-PTA) to postoperative LF-PTA at CI activation. Pre- and post-CI computed tomography was used to determine electrode scalar location and electrode translocation.Eighty-five adult CI candidates were enrolled. The mean (standard deviation [SD]) unaided preoperative LF-PTA across the sample was 54 (17) dB HL. For the whole sample, hearing preservation was "good" (i.e., LF-PTA change 0-15 dB) in 34.5%, "fair" (i.e., LF-PTA change15-29 dB) in 22.5%, and "poor" (i.e., LF-PTA change ≥30 dB) in 43%. For patients randomized to ECochG "on," mean (SD) LF-PTA change was 27 (20) dB compared with 27 (23) dB for patients randomized to ECochG "off" ( p = 0.89). Seven percent of patients, all of whom were randomized to ECochG off, showed electrode translocation from the scala tympani into the scala vestibuli.Although intracochlear ECochG during CI surgery has important prognostic utility, our data did not show significantly better hearing preservation in patients randomized to ECochG "on" compared with ECochG "off."
- Published
- 2022
7. Myocarditis Following COVID-19 Vaccination
- Author
-
Constantin A. Marschner, Kirsten E. Shaw, Felipe Sanchez Tijmes, Matteo Fronza, Sharmila Khullar, Michael A. Seidman, Paaladinesh Thavendiranathan, Jacob A. Udell, Rachel M. Wald, and Kate Hanneman
- Subjects
Male ,Myocarditis ,Young Adult ,COVID-19 Vaccines ,Adolescent ,Incidence ,Vaccination ,COVID-19 ,Humans ,General Medicine ,Cardiology and Cardiovascular Medicine - Abstract
Myocarditis is an established but rare adverse event following administration of messenger RNA-based coronavirus disease 2019 (COVID-19) vaccines and is most common in male adolescents and young adults. Symptoms typically develop within a few days of vaccine administration. Most patients have mild abnormalities on cardiac imaging with rapid clinical improvement with standard treatment. However, longer term follow-up is needed to determine whether imaging abnormalities persist, to evaluate for adverse outcomes, and to understand the risk associated with subsequent vaccination. The purpose of the review is to evaluate the current literature related to myocarditis following COVID-19 vaccination, including the incidence, risk factors, clinical course, imaging findings, and proposed pathophysiologic mechanisms.
- Published
- 2022
8. Microcalcification and Thoracic Aortopathy: A Window Into Disease Severity
- Author
-
Alexander J. Fletcher, Jennifer Nash, Maaz B.J. Syed, Mark G. Macaskill, Adriana A.S. Tavares, Niki Walker, Hannah Salcudean, Jonathon A. Leipsic, Kelvin H.H. Lim, Jillian Madine, William Wallace, Mark Field, David E. Newby, Rihab Bouchareb, Michael A. Seidman, Riaz Akhtar, and Stephanie L. Sellers
- Subjects
Calcinosis ,Humans ,Sodium Fluoride ,Cardiology and Cardiovascular Medicine ,Severity of Illness Index ,Aorta ,Elastin - Abstract
Background: Patients with thoracic aortopathy are at increased risk of catastrophic aortic dissection, carrying with it substantial mortality and morbidity. Although granular medial calcinosis (medial microcalcification) has been associated with thoracic aortopathy, its relationship to disease severity has yet to be established. Methods: One hundred one thoracic aortic specimens were collected from 57 patients with thoracic aortopathy and 18 control subjects. Standardized histopathologic scores, immunohistochemistry, and nanoindentation (tissue elastic modulus) were compared with the extent of microcalcification on von Kossa histology and 18F-sodium fluoride autoradiography. Results: Microcalcification content was higher in thoracic aortopathy samples with mild (n=28; 6.17 [2.71–10.39]; P ≤0.00010) or moderate histopathologic degeneration (n=30; 3.74 [0.87–11.80]; P P =0.0019) and OPN (osteopontin; n=26; P =0.0045) staining were increased in tissue with early aortopathy. Increasingly severe histopathologic degeneration was related to reduced microcalcification (n=82; Spearman ρ, −0.51; P P P =0.026). 18 F-sodium fluoride autoradiography demonstrated good correlation with histologically quantified microcalcification (n=66; r=0.76; P Conclusions: Medial microcalcification is a marker of aortopathy, although progression to severe aortopathy is associated with loss of both elastin fibers and microcalcification. 18 F-sodium fluoride positron emission tomography quantifies medial microcalcification and is a feasible noninvasive imaging modality for identifying aortic wall disruption with major translational promise.
- Published
- 2022
9. Progenitor cell therapy for acquired pediatric nervous system injury: Traumatic brain injury and acquired sensorineural hearing loss
- Author
-
Linda S. Baumgartner, Michael E. Baumgartner, David Shook, Steven A. Messina, Michael D. Seidman, Ernest J. Moore, and James E. Baumgartner
- Subjects
0301 basic medicine ,autologous stem cell transplantation ,bone marrow ,Hearing loss ,Traumatic brain injury ,Hearing Loss, Sensorineural ,Cell- and Tissue-Based Therapy ,Inflammation ,Bioinformatics ,clinical translation ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,Autologous stem-cell transplantation ,Brain Injuries, Traumatic ,medicine ,Humans ,Progenitor cell ,lcsh:QH573-671 ,Child ,lcsh:R5-920 ,business.industry ,lcsh:Cytology ,Cell Biology ,General Medicine ,progenitor cells ,medicine.disease ,030104 developmental biology ,medicine.anatomical_structure ,Multipotent Stem Cell ,umbilical cord blood ,Bone marrow ,medicine.symptom ,business ,lcsh:Medicine (General) ,030217 neurology & neurosurgery ,Developmental Biology ,Stem Cell Transplantation ,Perspectives - Abstract
While cell therapies hold remarkable promise for replacing injured cells and repairing damaged tissues, cell replacement is not the only means by which these therapies can achieve therapeutic effect. For example, recent publications show that treatment with varieties of adult, multipotent stem cells can improve outcomes in patients with neurological conditions such as traumatic brain injury and hearing loss without directly replacing damaged or lost cells. As the immune system plays a central role in injury response and tissue repair, we here suggest that multipotent stem cell therapies achieve therapeutic effect by altering the immune response to injury, thereby limiting damage due to inflammation and possibly promoting repair. These findings argue for a broader understanding of the mechanisms by which cell therapies can benefit patients., Injury to the central nervous system and ear lead to immediate neuron and hair cell loss (green), respectively. Neuron/hair cell loss continues over subsequent months, exacerbating neurological impairments. Recent studies indicate this could result from chronic inflammation and unresolved proinflammatory signals (red). Treatment with mesenchymal progenitor cells (blue) improves neuron/hair cell survival, potentially via anti‐inflammatory mechanisms.
- Published
- 2021
10. FANCJ compensates for RAP80 deficiency and suppresses genomic instability induced by interstrand cross-links
- Author
-
Robert M. Brosh, Arindam Datta, Marina A. Bellani, Sanket Awate, Christopher A. Dunn, Joshua A. Sommers, Michael M. Seidman, Sumeet Nayak, George Lucian Moldovan, Claudia M. Nicolae, Olivia Yang, and Sharon B. Cantor
- Subjects
Genome instability ,DNA Repair ,DNA damage ,DNA repair ,Mitomycin ,RAD51 ,Genome Integrity, Repair and Replication ,Genomic Instability ,Gene Knockout Techniques ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Chromosomal Instability ,Genetics ,Humans ,BRIP1 Gene ,DNA Breaks, Double-Stranded ,Histone Chaperones ,030304 developmental biology ,0303 health sciences ,biology ,BRCA1 Protein ,Recombinational DNA Repair ,Helicase ,Fanconi Anemia Complementation Group Proteins ,Cell biology ,DNA-Binding Proteins ,chemistry ,030220 oncology & carcinogenesis ,biology.protein ,Rad51 Recombinase ,Homologous recombination ,RNA Helicases ,DNA ,DNA Damage ,HeLa Cells - Abstract
FANCJ, a DNA helicase and interacting partner of the tumor suppressor BRCA1, is crucial for the repair of DNA interstrand crosslinks (ICL), a highly toxic lesion that leads to chromosomal instability and perturbs normal transcription. In diploid cells, FANCJ is believed to operate in homologous recombination (HR) repair of DNA double-strand breaks (DSB); however, its precise role and molecular mechanism is poorly understood. Moreover, compensatory mechanisms of ICL resistance when FANCJ is deficient have not been explored. In this work, we conducted a siRNA screen to identify genes of the DNA damage response/DNA repair regime that when acutely depleted sensitize FANCJ CRISPR knockout cells to a low concentration of the DNA cross-linking agent mitomycin C (MMC). One of the top hits from the screen was RAP80, a protein that recruits repair machinery to broken DNA ends and regulates DNA end-processing. Concomitant loss of FANCJ and RAP80 not only accentuates DNA damage levels in human cells but also adversely affects the cell cycle checkpoint, resulting in profound chromosomal instability. Genetic complementation experiments demonstrated that both FANCJ’s catalytic activity and interaction with BRCA1 are important for ICL resistance when RAP80 is deficient. The elevated RPA and RAD51 foci in cells co-deficient of FANCJ and RAP80 exposed to MMC are attributed to single-stranded DNA created by Mre11 and CtIP nucleases. Altogether, our cell-based findings together with biochemical studies suggest a critical function of FANCJ to suppress incompletely processed and toxic joint DNA molecules during repair of ICL-induced DNA damage.
- Published
- 2020
11. SimTube: A National Simulation Training and Research Project
- Author
-
Michael D. Seidman, Gregory J. Wiet, Marvin P. Fried, Nathan W. Callender, Sonya Malekzadeh, Amanda Onwuka, and Ellen S. Deutsch
- Subjects
Male ,medicine.medical_specialty ,medicine.medical_treatment ,Simulation training ,Myringotomy ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Medical physics ,Tube (fluid conveyance) ,Prospective Studies ,030223 otorhinolaryngology ,Simulation Training ,business.industry ,Internship and Residency ,Middle Ear Ventilation ,Surgical training ,Test (assessment) ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Feasibility Studies ,Female ,Surgery ,Clinical Competence ,business - Abstract
To test the feasibility and impact of a simulation training program for myringotomy and tube (MT) placement.Prospective randomized controlled.Multi-institutional.An MT simulator was used to assess the impact of simulation training vs no simulation training on the rate of achieving competency. Novice trainees were assessed using posttest simulator Objective Structured Assessment of Technical Skills (OSATS) scores, OSATS score for initial intraoperative tube insertion, and number of procedures to obtain competency. The effect of simulation training was analyzed using χA total of 101 residents and 105 raters from 65 institutions were enrolled; however, just 63 residents had sufficient data to be analyzed due to substantial breaches in protocol. There was no difference in simulator pretest scores between intervention and control groups; however, the intervention group had better OSATS global scores on the simulator (17.4 vs 13.7,A multi-institutional simulation study is feasible. Novices trained using the MT simulator achieved higher scores on simulator but not initial intraoperative OSATS, and they did not reach
- Published
- 2020
12. A Basis for Standardizing Superior Semicircular Canal Dehiscence Management
- Author
-
Michael D. Seidman, John T. Kennedy, and Ashley C. Cozart
- Subjects
Cranial Fossa, Middle ,Semicircular Canal Dehiscence ,Semicircular canal ,business.industry ,Dentistry ,Dehiscence ,Magnetic Resonance Imaging ,Vestibular Evoked Myogenic Potentials ,Labyrinth Diseases ,Mastoid ,Semicircular Canals ,Otolaryngology ,Hearing Aids ,medicine.anatomical_structure ,Otorhinolaryngology ,Surveys and Questionnaires ,Physician survey ,Audiometry, Pure-Tone ,Humans ,Medicine ,Practice Patterns, Physicians' ,Tomography, X-Ray Computed ,business - Abstract
Objectives: (1) To determine how otologic/neurotologic surgeons counsel patients with superior semicircular canal dehiscence (SSCD). (2) To understand the plethora of presenting symptoms associated with SSCD and appropriate management. (3) To suggest appropriate management; oftentimes avoiding surgery. Methods: This was a survey study of both community and academic physicians. A 23-question survey was distributed to all members of the American Neurotological (ANS) and American Otologic Societies (AOS) via email in the Fall of 2018. A total of 54 responses were received from a possible pool of 279 for a response rate of 19.4%. Inferences were made about the population through sample proportions and confidence intervals. Results: All respondents use computed tomography (CT) in diagnosing SSCD and 11.1% use CT exclusively. Cervical vestibular evoked myogenic potential (VEMP; 77.8%) are used more often than ocular VEMPs (38.9%). Magnetic resonance imaging (7.4%) is used infrequently; 96.3% of surgeons surveyed have seen patients with SSCD on imaging that are asymptomatic. Following surgical treatment, respondents reported balance issues and mild-to-moderate high-frequency sensorineural hearing loss (88.4%); 32.6% reported that the majority (>50%) of their patients needed further intervention after surgery, typically aggressive vestibular rehabilitation. Conclusions: There is a discrepancy in the systematic approach to SSCD between both the surgeons and the published literature. Patients with SSCD on ultra-high-resolution CT may have myriad symptoms while others are asymptomatic, and surgery may lead to additional complications. We will present a methodical recommendation to assist in the management of patients with SSCD depending upon their symptoms. This may improve patient selection, counseling, and outcomes.
- Published
- 2020
13. Native Aortic Valve Disease Progression and Bioprosthetic Valve Degeneration in Patients With Transcatheter Aortic Valve Implantation
- Author
-
Marc R. Dweck, Michelle C. Williams, Jacek Kwiecinski, Timothy R.G. Cartlidge, Jason M. Tarkin, Piotr J. Slomka, David E. Newby, Evangelos Tzolos, Damini Dey, Jonathon Leipsic, Nicholas L. Cruden, Gaurav S. Gulsin, Daniel S. Berman, Stephanie L. Sellers, Raj Makkar, Rong Bing, Mhairi K. Doris, Alexander J. Fletcher, Neal G. Uren, Edwin J R van Beek, Michael A. Seidman, Anna Kate Barton, James H.F. Rudd, Kwiecinski, Jacek [0000-0001-8202-6359], Tzolos, Evangelos [0000-0003-0038-043X], Fletcher, Alexander [0000-0001-9984-8391], Tarkin, Jason M [0000-0002-9132-120X], Seidman, Michael A [0000-0002-9594-827X], Barton, Anna K [0000-0002-7953-3015], Williams, Michelle C [0000-0003-3556-2428], van Beek, Edwin JR [0000-0002-2777-5071], Dey, Damini [0000-0003-2236-6970], Slomka, Piotr J [0000-0002-6110-938X], Newby, David E [0000-0001-7971-4628], Dweck, Marc R [0000-0001-9847-5917], and Apollo - University of Cambridge Repository
- Subjects
Aortic valve disease ,Aortic valve ,Male ,medicine.medical_specialty ,Transcatheter aortic ,18F-sodium fluoride ,Degeneration (medical) ,Prosthesis Design ,Disease activity ,Bioprosthetic valve ,Cohort Studies ,Transcatheter Aortic Valve Replacement ,Physiology (medical) ,Internal medicine ,Original Research Articles ,medicine ,Humans ,In patient ,transcatheter aortic valve implantation ,Positron Emission Tomography-Computed Tomography ,Aged ,Bioprosthesis ,Heart Valve Prosthesis Implantation ,Aged, 80 and over ,business.industry ,Aortic Valve Stenosis ,aortic valve ,Aortic Valve Disease ,Prosthesis Failure ,medicine.anatomical_structure ,Treatment Outcome ,positron emission tomography computed tomography ,Cross-Sectional Studies ,Heart Valve Prosthesis ,Cardiology ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,Disease Progression ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Supplemental Digital Content is available in the text., Background: Major uncertainties remain regarding disease activity within the retained native aortic valve, and regarding bioprosthetic valve durability, after transcatheter aortic valve implantation (TAVI). We aimed to assess native aortic valve disease activity and bioprosthetic valve durability in patients with TAVI in comparison with subjects with bioprosthetic surgical aortic valve replacement (SAVR). Methods: In a multicenter cross-sectional observational cohort study, patients with TAVI or bioprosthetic SAVR underwent baseline echocardiography, computed tomography angiography, and 18F-sodium fluoride (18F-NaF) positron emission tomography. Participants (n=47) were imaged once with 18F-NaF positron emission tomography/computed tomography either at 1 month (n=9, 19%), 2 years (n=22, 47%), or 5 years (16, 34%) after valve implantation. Patients subsequently underwent serial echocardiography to assess for changes in valve hemodynamic performance (change in peak aortic velocity) and evidence of structural valve dysfunction. Comparisons were made with matched patients with bioprosthetic SAVR (n=51) who had undergone the same imaging protocol. Results: In patients with TAVI, native aortic valves demonstrated 18F-NaF uptake around the outside of the bioprostheses that showed a modest correlation with the time from TAVI (r=0.36, P=0.023). 18F-NaF uptake in the bioprosthetic leaflets was comparable between the SAVR and TAVI groups (target-to-background ratio, 1.3 [1.2–1.7] versus 1.3 [1.2–1.5], respectively; P=0.27). The frequencies of imaging evidence of bioprosthetic valve degeneration at baseline were similar on echocardiography (6% versus 8%, respectively; P=0.78), computed tomography (15% versus 14%, respectively; P=0.87), and positron emission tomography (15% versus 29%, respectively; P=0.09). Baseline 18F-NaF uptake was associated with a subsequent change in peak aortic velocity for both TAVI (r=0.7, P
- Published
- 2021
14. Alpha-synuclein seeding shows a wide heterogeneity in multiple system atrophy
- Author
-
Ivan Martinez-Valbuena, Naomi P. Visanji, Ain Kim, Heather H. C. Lau, Raphaella W. L. So, Sohaila Alshimemeri, Andrew Gao, Michael A. Seidman, Maria R. Luquin, Joel C. Watts, Anthony E. Lang, and Gabor G. Kovacs
- Subjects
Seeding behavior ,Synucleinopathies ,Cognitive Neuroscience ,RT-QuIC ,Brain ,Multiple System Atrophy ,nervous system diseases ,Cellular and Molecular Neuroscience ,nervous system ,Parkinsonian Disorders ,mental disorders ,alpha-Synuclein ,Humans ,Neurology (clinical) ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background Multiple system atrophy (MSA) is a neurodegenerative condition characterized by variable combinations of parkinsonism, autonomic failure, cerebellar ataxia and pyramidal features. Although the distribution of synucleinopathy correlates with the predominant clinical features, the burden of pathology does not fully explain observed differences in clinical presentation and rate of disease progression. We hypothesized that the clinical heterogeneity in MSA is a consequence of variability in the seeding activity of α-synuclein both between different patients and between different brain regions. Methods The reliable detection of α-synuclein seeding activity derived from MSA using cell-free amplification assays remains challenging. Therefore, we conducted a systematic evaluation of 168 different reaction buffers, using an array of pH and salts, seeded with fully characterized brain homogenates from one MSA and one PD patient. We then validated the two conditions that conferred the optimal ability to discriminate between PD- and MSA-derived samples in a larger cohort of 40 neuropathologically confirmed cases, including 15 MSA. Finally, in a subset of brains, we conducted the first multi-region analysis of seeding behaviour in MSA. Results Using our novel buffer conditions, we show that the physicochemical factors that govern the in vitro amplification of α-synuclein can be tailored to generate strain-specific reaction buffers that can be used to reliably study the seeding capacity from MSA-derived α-synuclein. Using this novel approach, we were able to sub-categorize the 15 MSA brains into 3 groups: high, intermediate and low seeders. To further demonstrate heterogeneity in α-synuclein seeding in MSA, we conducted a comprehensive multi-regional evaluation of α-synuclein seeding in 13 different regions from 2 high seeders, 2 intermediate seeders and 2 low seeders. Conclusions We have identified unexpected differences in seed-competent α-synuclein across a cohort of neuropathologically comparable MSA brains. Furthermore, our work has revealed a substantial heterogeneity in seeding activity, driven by the PBS-soluble α-synuclein, between different brain regions of a given individual that goes beyond immunohistochemical observations. Our observations pave the way for future subclassification of MSA, which exceeds conventional clinical and neuropathological phenotyping and considers the structural and biochemical heterogeneity of α-synuclein present. Finally, our methods provide an experimental framework for the development of vitally needed, rapid and sensitive diagnostic assays for MSA.
- Published
- 2021
15. Myeloperoxidase–Antineutrophil Cytoplasmic Antibody–Associated Vasculitis Preceded by Temporal Arteritis and Sjögren Syndrome
- Author
-
Michael A. Seidman, Natasha Dehghan, Darra T. Murphy, and Derin Karacabeyli
- Subjects
Pathology ,medicine.medical_specialty ,biology ,business.industry ,Giant Cell Arteritis ,Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis ,Sjögren syndrome ,medicine.disease ,Antibodies, Antineutrophil Cytoplasmic ,Sjogren's Syndrome ,Rheumatology ,Myeloperoxidase ,medicine ,biology.protein ,Humans ,Arteritis ,business ,Vasculitis ,Peroxidase ,Anti-neutrophil cytoplasmic antibody - Published
- 2020
16. An optimized proximity ligation assay to detect telomere dysfunction induced foci in human and mouse cells
- Author
-
Yajun, Wang, Luigi, Ferrucci, Michael M, Seidman, and Yie, Liu
- Subjects
Mice ,General Immunology and Microbiology ,General Neuroscience ,Animals ,Fluorescent Antibody Technique ,Humans ,Telomere ,In Situ Hybridization, Fluorescence ,General Biochemistry, Genetics and Molecular Biology - Abstract
Telomere dysfunction-induced foci (TIF) can be measured by immunofluorescence, combined with telomere-fluorescent
- Published
- 2022
17. Defective postreplication repair of UV photoproducts in melanoma: a mutator phenotype
- Author
-
Michael M. Seidman and Douglas E. Brash
- Subjects
0301 basic medicine ,Cancer Research ,DNA Repair ,MASTL ,chemistry.chemical_compound ,0302 clinical medicine ,Protein Phosphatase 2 ,RNA-Seq ,RNA, Small Interfering ,Melanoma ,Research Articles ,Oligonucleotide Array Sequence Analysis ,postreplication repair ,General Medicine ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,3. Good health ,Up-Regulation ,G2 Phase Cell Cycle Checkpoints ,Gene Expression Regulation, Neoplastic ,Phenotype ,Oncology ,030220 oncology & carcinogenesis ,Molecular Medicine ,Microtubule-Associated Proteins ,Cytosine ,Research Article ,DNA Replication ,ultraviolet radiation ,Ultraviolet Rays ,Biology ,Protein Serine-Threonine Kinases ,lcsh:RC254-282 ,03 medical and health sciences ,Cell Line, Tumor ,Genetics ,Postreplication repair ,medicine ,Humans ,Mutator phenotype ,Recombinational DNA Repair ,DNA ,medicine.disease ,Phosphoproteins ,Thymine ,G2 phase checkpoint ,030104 developmental biology ,chemistry ,Polyribosomes ,Mutation ,Cancer research ,Commentary ,Genome-Wide Association Study - Abstract
Ultraviolet radiation‐induced DNA mutations are a primary environmental driver of melanoma. The reason for this very high level of unrepaired DNA lesions leading to these mutations is still poorly understood. The primary DNA repair mechanism for UV‐induced lesions, that is, the nucleotide excision repair pathway, appears intact in most melanomas. We have previously reported a postreplication repair mechanism that is commonly defective in melanoma cell lines. Here we have used a genome‐wide approach to identify the components of this postreplication repair mechanism. We have used differential transcript polysome loading to identify transcripts that are associated with UV response, and then functionally assessed these to identify novel components of this repair and cell cycle checkpoint network. We have identified multiple interaction nodes, including global genomic nucleotide excision repair and homologous recombination repair, and previously unexpected MASTL pathway, as components of the response. Finally, we have used bioinformatics to assess the contribution of dysregulated expression of these pathways to the UV signature mutation load of a large melanoma cohort. We show that dysregulation of the pathway, especially the DNA damage repair components, are significant contributors to UV mutation load, and that dysregulation of the MASTL pathway appears to be a significant contributor to high UV signature mutation load., The UV‐G2 checkpoint is triggered by UV‐induced DNA lesions not repaired by NER during G1 phase. Global genomic NER (GG‐NER) pathway repairs these lesions during G2 phase, and homologous recombination repair (HRR) repairs the single‐stranded gaps. The MASTL pathway controls exit from the checkpoint arrest. These are all under AKT‐dependent translational control.
- Published
- 2019
18. Loss of ARID1A in Tumor Cells Renders Selective Vulnerability to Combined Ionizing Radiation and PARP Inhibitor Therapy
- Author
-
Youngran Park, Zheng Cheng Yu, Ayse Ayhan, Tian Li Wang, Raghavendra A. Shamanna, Ie Ming Shih, Sonia Franco, Akila N. Viswanathan, Michael M. Seidman, Vilhelm A. Bohr, M. Herman Chui, Marina A. Bellani, Stephanie Gaillard, Yohan Suryo Rahmanto, and Anthony K.L. Leung
- Subjects
0301 basic medicine ,Cancer Research ,DNA End-Joining Repair ,DNA Repair ,Cell Survival ,DNA repair ,DNA damage ,Poly ADP ribose polymerase ,Cell Cycle Proteins ,Mice, Transgenic ,Poly(ADP-ribose) Polymerase Inhibitors ,Models, Biological ,Radiation Tolerance ,Article ,Chromatin remodeling ,Olaparib ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Cell Line, Tumor ,Animals ,Humans ,DNA Breaks, Double-Stranded ,Chromatin ,DNA-Binding Proteins ,Disease Models, Animal ,030104 developmental biology ,Oncology ,chemistry ,Drug Resistance, Neoplasm ,Gene Knockdown Techniques ,030220 oncology & carcinogenesis ,PARP inhibitor ,Cancer cell ,Cancer research ,DNA Damage ,Transcription Factors - Abstract
Purpose: Somatic inactivating mutations in ARID1A, a component of the SWI/SNF chromatin remodeling complex, are detected in various types of human malignancies. Loss of ARID1A compromises DNA damage repair. The induced DNA damage burden may increase reliance on PARP-dependent DNA repair of cancer cells to maintain genome integrity and render susceptibility to PARP inhibitor therapy. Experimental Design: Isogenic ARID1A−/− and wild-type cell lines were used for assessing DNA damage response, DNA compactness, and profiling global serine/threonine phosphoproteomic in vivo. A panel of inhibitors targeting DNA repair pathways was screened for a synergistic antitumor effect with irradiation in ARID1A−/− tumors. Results: ARID1A-deficient endometrial cells exhibit sustained levels in DNA damage response, a result further supported by in vivo phosphoproteomic analysis. Our results show that ARID1A is essential for establishing an open chromatin state upon DNA damage, a process required for recruitment of 53BP1 and RIF1, key mediators of non-homologous end-joining (NHEJ) machinery, to DNA lesions. The inability of ARID1A−/− cells to mount NHEJ repair results in a partial cytotoxic response to radiation. Small-molecule compound screens revealed that PARP inhibitors act synergistically with radiation to potentiate cytotoxicity in ARID1A−/− cells. Combination treatment with low-dose radiation and olaparib greatly improved antitumor efficacy, resulting in long-term remission in mice bearing ARID1A-deficient tumors. Conclusions: ARID1A-deficient cells acquire high sensitivity to PARP inhibition after exposure to exogenously induced DNA breaks such as ionizing radiation. Our findings suggest a novel biologically informed strategy for treating ARID1A-deficient malignancies.
- Published
- 2019
19. Surgical Neuromodulation of Tinnitus: A Review of Current Therapies and Future Applications
- Author
-
Rushna Ali, Michael D Seidman, Aqueel H. Pabaney, Richard Rammo, and Jason M. Schwalb
- Subjects
Auditory Pathways ,Deep brain stimulation ,Deep Brain Stimulation ,medicine.medical_treatment ,Stimulation ,Tinnitus ,03 medical and health sciences ,0302 clinical medicine ,Sensation ,otorhinolaryngologic diseases ,medicine ,Humans ,business.industry ,Brain ,General Medicine ,Medial geniculate body ,Magnetic Resonance Imaging ,Transcranial Magnetic Stimulation ,Functional imaging ,Transcranial magnetic stimulation ,Anesthesiology and Pain Medicine ,Neurology ,Transcutaneous Electric Nerve Stimulation ,Neurology (clinical) ,medicine.symptom ,business ,Neuroscience ,030217 neurology & neurosurgery ,Vagus nerve stimulation ,Forecasting - Abstract
Introduction Tinnitus is the conscious perception of an auditory sensation in the absence of external stimulus. Proposed theories are based on neuroplastic changes that occur due to sensory deprivation. The authors review the relevant literature on functional imaging and neuromodulation of tinnitus and describe potential targets for deep brain stimulation (DBS). Materials and methods A MEDLINE keyword and Medical Subject Heading term literature search was performed using PubMed for tinnitus, neuromodulation, DBS, transcranial magnetic stimulation, epidural electrode stimulation, intradural electrode stimulation, functional imaging, and connectivity. Data from these reports were extracted and reviewed. Results Multiple imaging studies are employed to understand the pathophysiology of tinnitus. Abnormal regions and altered connectivity implicated in tinnitus include auditory pathway and limbic structures. Neuromodulation attempts to correct this hyperexcitable state by disrupting these aberrant oscillations and returning activity to baseline. Applied treatment modalities include transcranial magnetic stimulation, epidural/intradural electrode stimulation, and DBS. More recently, modulation of autonomic pathways through vagus nerve stimulation and paired auditory sounds has demonstrated tinnitus improvement via plasticity changes. Conclusions DBS shows much promise as a therapeutic option for tinnitus. Stimulation of the auditory pathway, particularly the medial geniculate body, could counteract thalamocortical dysrhythmias and reduce gamma activity implicated in the tinnitus percept. Stimulation of the limbic pathway could decrease attention to and perception of tinnitus. Additional studies, focusing on the involvement of thalamic and limbic structures in the pathophysiology of tinnitus, are needed to support the use of DBS.
- Published
- 2019
20. Iatrogenic embolization following cardiac intervention: postmortem analysis of 110 cases
- Author
-
Hamid Masoudi, James Caldwell, John Maguire, Jason B Chew, Michael A. Seidman, Asaf Honig, Tyler B. M. Hickey, and Avrum Ostry
- Subjects
Adult ,Male ,0301 basic medicine ,Cardiac Catheterization ,medicine.medical_specialty ,Time Factors ,Computed Tomography Angiography ,Polymers ,medicine.medical_treatment ,Embolism ,Iatrogenic Disease ,Infarction ,Autopsy ,030204 cardiovascular system & hematology ,Air embolism ,Pathology and Forensic Medicine ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Hydrophilic polymers ,Foreign-Body Migration ,Risk Factors ,Cause of Death ,medicine ,Embolism, Air ,Humans ,cardiovascular diseases ,Embolization ,Stroke ,Aged ,Retrospective Studies ,Cause of death ,Aged, 80 and over ,business.industry ,Endovascular Procedures ,Calcinosis ,General Medicine ,Middle Aged ,Atherosclerosis ,medicine.disease ,Cerebral Angiography ,Catheter ,030104 developmental biology ,cardiovascular system ,Female ,Radiology ,Cardiology and Cardiovascular Medicine ,business - Abstract
Introduction Iatrogenic embolization following cardiac investigative procedures may result from hydrophilic polymer emboli (HPE) from catheter valve and vessel wall calcifications, and air embolism from open heart surgery. This retrospective clinical pathologic analysis was undertaken to ascertain the frequency and extent of these potentially fatal complications. Methods This retrospective clinical pathologic autopsy analysis with premortem diagnostic imaging correlation identified 110 individuals who had undergone endovascular procedures between 2010 and 2016 within 90 days of death and followed by hospital autopsy. Clinical outcomes, radiologic studies, and autopsy materials were reviewed. Results Iatrogenic emboli were assessed as causing death in 9/110 autopsy cases (8.2%) and 9/34 (26.5%) cases with proven iatrogenic emboli. Iatrogenic emboli caused strokes in 10/110 (9.1%) autopsy cases including calcified emboli (CE, n=6), HPE (n=2), cardiac valvular tissue (n=1), and air embolism (n=1). Seven cases of calcified emboli complicating endovascular procedures were identified: four of the CE were thought to be the cause of death due to fatal strokes (n=2) and fatal myocardial (n=1) and colonic infarction (n=1). The CE likely originated from calcified aortic valves and atherosclerotic aortic plaques. Histologic evidence of HPE was found in 23% (25/110) of cases; 54% (26/48) showed evidence of infarction in postprocedural imaging, with radiologic evidence of infarction in 32% (8/25) of cases with HPE histology. Endovascular aortic repair was associated with the greatest density/distribution of HPE. HPE material showed degradation with time and was often associated with an inflammatory response. HPE directly contributed to death in three cases. One fatal air embolism followed open heart surgery, and one cardiac tissue embolus resulted in a major stroke. Conclusions We advocate for greater awareness of these underrecognized and occasionally fatal complications of endovascular procedures. Targeted postprocedural imaging has a role in the identification of iatrogenic embolic infarcts.
- Published
- 2019
21. Surgical Management for Dysplastic or Congenitally Absent Oval Window
- Author
-
Michael D. Seidman and Drue Manning
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Hearing Loss, Conductive ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Humans ,Medicine ,Oval Window, Ear ,Child ,030223 otorhinolaryngology ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Oval window ,Treatment options ,Middle Aged ,medicine.disease ,Institutional review board ,Facial nerve ,Sensory Systems ,Conductive hearing loss ,Surgery ,medicine.anatomical_structure ,Otorhinolaryngology ,Hearing results ,Middle ear ,Female ,Neurology (clinical) ,Audiometry ,Otologic Surgical Procedures ,business ,030217 neurology & neurosurgery - Abstract
OBJECTIVE To evaluate surgical findings and hearing results for patient's undergoing the described surgical approach for congenitally absent or dysplastic oval window (OW). STUDY DESIGN The Institutional Review Board approved retrospective review of patients with conductive hearing loss (CHL) operated on from 1992 to 2016. SETTING Academic tertiary center. PATIENTS Patients with CHL, an intact tympanic membrane (TM), and without history of chronic infection underwent middle ear exploration. Eleven patients and 13 ears underwent an oval window drill-out (OWD) procedure. INTERVENTION Eleven patients presented, all with dysplastic or congenitally absent oval window (CAOW). CHL was identified using audiometry and tuning forks, many patients also had preoperative computed tomography temporal bones. A transcanal approach was used and an OWD was performed with a variety of prostheses placed. MAIN OUTCOME MEASURE Audiometric studies before and after intervention were compared with 12 month and long-term follow-up (1-22 yr). RESULTS Preoperative air-bone gaps ranged from 40 to 60 dB and averaged 55.1 dB. Postoperative air-bone gaps ranged from 0 to 60 dB and averaged 24.1 dB. The preoperative pure-tone average (PTA) ranged from 55 to 99 dB and averaged 71.3 dB. Postoperative PTA ranged from 21 to 108 dB and averaged 49.6 dB. CONCLUSION Dysplastic and CAOW are uncommon congenital major ear anomalies. OWD is a viable treatment option, though careful counseling is critical, as significant complications are possible, especially with facial nerve (FN) abnormalities. This series demonstrates successful closure of the air-bone gap for many patients with this technique.
- Published
- 2018
22. Low LAL (Lysosomal Acid Lipase) Expression by Smooth Muscle Cells Relative to Macrophages as a Mechanism for Arterial Foam Cell Formation
- Author
-
Collin S Pryma, Carleena Ortega, Katrina J. Besler, Teddy Chan, Joshua A. Dubland, Ying Wang, Michael A. Seidman, Sima Allahverdian, Gordon A. Francis, and Kamel Boukais
- Subjects
Apolipoprotein E ,Male ,Mice, Knockout, ApoE ,Myocytes, Smooth Muscle ,Muscle, Smooth, Vascular ,Article ,chemistry.chemical_compound ,Mice ,Downregulation and upregulation ,Myocyte ,Animals ,Humans ,Aorta ,Foam cell ,Mice, Inbred BALB C ,biology ,Cholesterol ,Sterol Esterase ,Atherosclerosis ,Molecular biology ,Mice, Inbred C57BL ,Cytosol ,Disease Models, Animal ,RAW 264.7 Cells ,chemistry ,ABCA1 ,cardiovascular system ,biology.protein ,lipids (amino acids, peptides, and proteins) ,Cardiology and Cardiovascular Medicine ,Lipoprotein ,Foam Cells - Abstract
Objective: We previously reported smooth muscle cells (SMCs) represent ≥50% of foam cells in human coronary and ≈70% in apoE (apolipoprotein E)-deficient mouse aortic atheromas and exhibit reduced expression of the cholesterol exporter ABCA1 (ATP-binding cassette transporter A1). A major stimulus for ABCA1 expression is flux of cholesterol out of lysosomes, generated by hydrolysis of lipoprotein cholesteryl esters by LAL (lysosomal acid lipase). In this study, we investigated the potential role lysosomal dysfunction might play in foam cell formation by arterial SMCs. Approach and Results: Human monocyte-derived macrophages (macrophages) and arterial SMCs were treated with aggregated LDL (low-density lipoprotein) to increase intracellular cholesterol and investigated for lysosomal and postlysosomal cholesterol metabolism defects. Human and mouse atheromas were analyzed for LAL expression. Unlike macrophages, aggregated LDL uptake failed to upregulate ABCA1 expression, downregulate new cholesterol synthesis, or to significantly increase 27-hydroxycholesterol levels in SMCs. Confocal microscopy revealed retention of neutral lipids within lysosomal compartments in SMCs, while macrophages showed most lipids as cytosolic droplets. LIPA (lipase A) mRNA levels and LAL protein were markedly reduced in SMCs. Treatment of SMCs with medium containing LAL resulted in significantly reduced lysosomal lipid accumulation and increased cholesterol efflux to apoA-I (apolipoprotein AI). Human and mouse atheromas exhibited low LAL/ Lipa expression in intimal SMCs when compared with intimal macrophages. Conclusions: These findings indicate the inherently low level of LAL in SMCs compared with macrophages is associated with reduced capacity to catabolize atherogenic lipoproteins and is a mechanism for SMC foam cell formation in atherosclerosis.
- Published
- 2021
23. Inflammatory Comments in Coronary Artery Disease: When to Suspect Polyarteritis Nodosa or Other Primary Systemic Vasculitis
- Author
-
Youheng Xie and Michael A. Seidman
- Subjects
Vasculitis ,medicine.medical_specialty ,Polyarteritis nodosa ,business.industry ,Systemic Vasculitis ,Coronary Artery Disease ,medicine.disease ,Dermatology ,Polyarteritis Nodosa ,Coronary artery disease ,medicine ,Humans ,Suspect ,Cardiology and Cardiovascular Medicine ,business ,Systemic vasculitis - Published
- 2020
24. Ex vivo 18F-fluoride uptake and hydroxyapatite deposition in human coronary atherosclerosis
- Author
-
David E. Newby, Michael A. Seidman, Ralph Bouhaidar, Adriana Tavares, Jonathon Leipsic, Philip D Adamson, Alastair J Moss, Jack Andrews, Anoop S V Shah, Mhairi K. Doris, Marc R. Dweck, Vicky E MacRae, Michelle C. Williams, Carlos J. Alcaide-Corral, Alisia M Sim, and Stephanie L. Sellers
- Subjects
0301 basic medicine ,Adult ,Male ,Pathology ,medicine.medical_specialty ,Fluorine Radioisotopes ,Imaging biomarker ,Cardiology ,lcsh:Medicine ,Core Binding Factor Alpha 1 Subunit ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,Spectrum Analysis, Raman ,Article ,03 medical and health sciences ,0302 clinical medicine ,Organ Culture Techniques ,Osteogenesis ,Positron Emission Tomography Computed Tomography ,medicine ,Cadaver ,Humans ,Osteopontin ,Nuclear protein ,lcsh:Science ,Transcription factor ,Coronary atherosclerosis ,Aged ,Multidisciplinary ,biology ,Molecular medicine ,business.industry ,lcsh:R ,X-Ray Microtomography ,Middle Aged ,Plaque, Atherosclerotic ,030104 developmental biology ,medicine.anatomical_structure ,Durapatite ,biology.protein ,lcsh:Q ,Female ,18f fluoride ,business ,Ex vivo ,Biomarkers ,Artery - Abstract
Early microcalcification is a feature of coronary plaques with an increased propensity to rupture and to cause acute coronary syndromes. In this ex vivo imaging study of coronary artery specimens, the non-invasive imaging radiotracer, 18F-fluoride, was highly selective for hydroxyapatite deposition in atherosclerotic coronary plaque. Specifically, coronary 18F-fluoride uptake had a high signal to noise ratio compared with surrounding myocardium that makes it feasible to identify coronary mineralisation activity. Areas of 18F-fluoride uptake are associated with osteopontin, an inflammation-associated glycophosphoprotein that mediates tissue mineralisation, and Runt-related transcription factor 2, a nuclear protein involved in osteoblastic differentiation. These results suggest that 18F-fluoride is a non-invasive imaging biomarker of active coronary atherosclerotic mineralisation.
- Published
- 2020
25. DONSON and FANCM associate with different replisomes distinguished by replication timing and chromatin domain
- Author
-
Gavin S. McNee, Jing Zhang, Durga Pokharel, Grant S. Stewart, Ryan C James, Yongqing Zhang, John J. Reynolds, Michael M. Seidman, Marina A. Bellani, and Andrew P. Jackson
- Subjects
0301 basic medicine ,Euchromatin ,DNA Replication Timing ,Heterochromatin ,Science ,General Physics and Astronomy ,Cell Cycle Proteins ,Heterochromatin/metabolism ,02 engineering and technology ,Biology ,Article ,Chromosomes ,General Biochemistry, Genetics and Molecular Biology ,S Phase ,chemistry.chemical_compound ,03 medical and health sciences ,Gene duplication ,Humans ,FANCM ,lcsh:Science ,030304 developmental biology ,Nuclear Proteins/metabolism ,0303 health sciences ,Replication timing ,Multidisciplinary ,Cell Cycle Proteins/metabolism ,030302 biochemistry & molecular biology ,DNA Helicases ,Nuclear Proteins ,General Chemistry ,021001 nanoscience & nanotechnology ,DNA Helicases/metabolism ,Cell biology ,Chromatin ,030104 developmental biology ,chemistry ,Chromatin Immunoprecipitation Sequencing ,Euchromatin/metabolism ,Replisome ,lcsh:Q ,0210 nano-technology ,DNA ,HeLa Cells - Abstract
Duplication of mammalian genomes requires replisomes to overcome numerous impediments during passage through open (eu) and condensed (hetero) chromatin. Typically, studies of replication stress characterize mixed populations of challenged and unchallenged replication forks, averaged across S phase, and model a single species of “stressed” replisome. Here, in cells containing potent obstacles to replication, we find two different lesion proximal replisomes. One is bound by the DONSON protein and is more frequent in early S phase, in regions marked by euchromatin. The other interacts with the FANCM DNA translocase, is more prominent in late S phase, and favors heterochromatin. The two forms can also be detected in unstressed cells. ChIP-seq of DNA associated with DONSON or FANCM confirms the bias of the former towards regions that replicate early and the skew of the latter towards regions that replicate late., Eukaryotic replisomes are multiprotein complexes. Here the authors reveal two distinct stressed replisomes, associated with DONSON and FANCM, displaying a bias in replication timing and chromatin domain.
- Published
- 2020
26. Do These Genes Make My Heart Look Fat? Why Molecular Changes Matter in Congenital Heart Disease
- Author
-
Susan M. Armstrong and Michael A. Seidman
- Subjects
Adult ,Heart Defects, Congenital ,medicine.medical_specialty ,Heart disease ,business.industry ,MEDLINE ,Heart ,medicine.disease ,Internal medicine ,medicine ,Cardiology ,Tetralogy of Fallot ,Humans ,Cardiology and Cardiovascular Medicine ,business ,Gene - Published
- 2020
27. Alternative Treatments of Tinnitus: Alternative Medicine
- Author
-
Friederike S, Luetzenberg, Seilesh, Babu, and Michael D, Seidman
- Subjects
Complementary Therapies ,Minerals ,Tinnitus ,Treatment Outcome ,Cannabinoids ,Humans ,Vitamins ,Transcranial Magnetic Stimulation ,Drugs, Chinese Herbal - Abstract
"Because Western medicine has remained largely unsuccessful at treating tinnitus symptoms, many physicians as well as patients have turned to alternative treatment options to decrease patients' suffering and improve their quality of life. Although research in complementary/integrative medicine continues to be scarce and inconclusive, studies are pointing toward the positive effects of acupuncture, herbal remedies, dietary supplements, antioxidants, melatonin, and hypnosis on tinnitus. Although the efficacies of these treatments are inconsistent and may depend on a patient's unique circumstances, studies acknowledge that each treatment is worth trying in light of the potential benefits while being both noninvasive and well tolerated."
- Published
- 2020
28. Tricuspid Valve-in-Valve and Bioprosthetic Surgical Tricuspid and Pulmonic Valve Degeneration: Lessons From Imaging and Histopathology
- Author
-
Stephanie L, Sellers, Mark, Hensey, Timothy R G, Cartlidge, Christopher T, Turner, Karen, Lau, Althea, Lai, Hannah, Salcudean, Janarthanan, Sathananthan, Bruce M, McManus, David J, Granville, Geoffrey W, Payne, Philippe, Pibarot, John G, Webb, David E, Newby, Philipp, Blanke, Michael A, Seidman, Marc R, Dweck, and Jonathon A, Leipsic
- Subjects
Bioprosthesis ,Heart Valve Prosthesis Implantation ,Predictive Value of Tests ,Heart Valve Prosthesis ,Humans ,Tricuspid Valve ,Tricuspid Valve Insufficiency - Published
- 2020
29. Clinical Practice Guideline: Nosebleed (Epistaxis)
- Author
-
Venu Vadlamudi, Peter J. Abramson, David E. Tunkel, Richard M. Rosenfeld, Stacey L. Ishman, John S. Schneider, David M. Poetker, Jesse M. Hackell, Samantha Anne, Jacqueline D. Alikhaani, Lorraine C. Nnacheta, Spencer C. Payne, Boris Chernobilsky, Margo McKenna Benoit, Meredith Lind, Eric H. Holbrook, Kenneth W. Lin, Sarah M. Holdsworth, Michael D. Brown, David A Feldstein, Rachel S. Bercovitz, Tulio A. Valdez, Taskin M. Monjur, Charles A. Riley, and Michael D. Seidman
- Subjects
medicine.medical_specialty ,Cautery ,Nasal Surgical Procedures ,Hemostatics ,03 medical and health sciences ,0302 clinical medicine ,Patient Education as Topic ,Risk Factors ,medicine ,Humans ,Tampons, Surgical ,Vasoconstrictor Agents ,Nasal cautery ,030223 otorhinolaryngology ,Ligation ,business.industry ,General surgery ,Patient Acuity ,Endoscopy ,Guideline ,Nosebleed ,Quality Improvement ,Nasal packing ,Clinical Practice ,Epistaxis ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Telangiectasia, Hereditary Hemorrhagic ,Surgery ,medicine.symptom ,business - Abstract
The primary purpose of this multidisciplinary guideline is to identify quality improvement opportunities in the management of nosebleeds and to create clear and actionable recommendations to implement these opportunities in clinical practice. Specific goals of this guideline are to promote best practices, reduce unjustified variations in care of patients with nosebleeds, improve health outcomes, and minimize the potential harms of nosebleeds or interventions to treat nosebleeds. The target patient for the guideline is any individual aged ≥3 years with a nosebleed or history of nosebleed who needs medical treatment or seeks medical advice. The target audience of this guideline is clinicians who evaluate and treat patients with nosebleed. This includes primary care providers such as family medicine physicians, internists, pediatricians, physician assistants, and nurse practitioners. It also includes specialists such as emergency medicine providers, otolaryngologists, interventional radiologists/neuroradiologists and neurointerventionalists, hematologists, and cardiologists. The setting for this guideline includes any site of evaluation and treatment for a patient with nosebleed, including ambulatory medical sites, the emergency department, the inpatient hospital, and even remote outpatient encounters with phone calls and telemedicine. Outcomes to be considered for patients with nosebleed include control of acute bleeding, prevention of recurrent episodes of nasal bleeding, complications of treatment modalities, and accuracy of diagnostic measures. This guideline addresses the diagnosis, treatment, and prevention of nosebleed. It focuses on nosebleeds that commonly present to clinicians via phone calls, office visits, and emergency room encounters. This guideline discusses first-line treatments such as nasal compression, application of vasoconstrictors, nasal packing, and nasal cautery. It also addresses more complex epistaxis management, which includes the use of endoscopic arterial ligation and interventional radiology procedures. Management options for 2 special groups of patients-patients with hereditary hemorrhagic telangiectasia syndrome and patients taking medications that inhibit coagulation and/or platelet function-are included in this guideline. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group. It is not intended to be a comprehensive, general guide for managing patients with nosebleed. In this context, the purpose is to define useful actions for clinicians, generalists, and specialists from a variety of disciplines to improve quality of care. Conversely, the statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.The guideline development group made
- Published
- 2020
30. IL-6 expression is correlated with increased T-cell proliferation and survival in the arterial wall in giant cell arteritis
- Author
-
Kamran Shojania, J Antonio Aviña-Zubieta, Kevin Rey, Zongshu Luo, Winnie Enns, Michael A. Seidman, Sukhbir Manku, Jonathan C. Choy, Wendy Wong, and Zainab Alabdurubalnabi
- Subjects
CD4-Positive T-Lymphocytes ,Male ,Cell Survival ,T cell ,Giant Cell Arteritis ,Apoptosis ,Lymphocyte Activation ,T-Lymphocytes, Regulatory ,Pathology and Forensic Medicine ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,immune system diseases ,medicine ,Humans ,Arterial wall ,RNA, Messenger ,Interleukin 6 ,Aged ,Cell Proliferation ,Aged, 80 and over ,030203 arthritis & rheumatology ,Messenger RNA ,biology ,Interleukin-6 ,General Medicine ,medicine.disease ,Temporal Arteries ,Blockade ,Giant cell arteritis ,medicine.anatomical_structure ,biology.protein ,Cancer research ,Female ,Cardiology and Cardiovascular Medicine ,Vasculitis ,030215 immunology - Abstract
Giant cell arteritis (GCA) is the most common vasculitis in adults affecting large and medium-sized arteries. IL-6 and T cell accumulation within the arterial wall contribute to the pathogenesis of GCA, and blockade of IL-6 activity is efficacious in its treatment. We examined the relationship between levels of IL-6 expression and immunological processes that control the expansion of T cells in GCA-positive temporal artery biopsies. CD4 T cells accumulated in clusters within the media and deep intima of all GCA lesions. There was a significant positive correlation between the expression of IL-6 mRNA and increased frequency of proliferating CD4 T cells. The expansion of T cells can be inhibited by T regs but IL-6 expression was not correlated with differences in T reg accumulation. Increased IL-6 levels were also significantly correlated with lower frequencies of CD4 T cells undergoing apoptotic cell death. In conclusion, IL-6 may contribute to the accumulation of CD4 T cells in GCA by supporting their proliferation and survival within the arterial wall through mechanisms that are independent of effects on local T reg expansion.
- Published
- 2018
31. Utility of Serum IgG4 Levels in a Multiethnic Population
- Author
-
David R. Collins, Robert Irvine, Michael A. Seidman, Andre Mattman, Eric Lam, Ruyu Qi, Luke Y.C. Chen, Vivian T. Yin, Sujin Park, Mollie N. Carruthers, J. Kelsall, and Graham W. Slack
- Subjects
Male ,medicine.medical_specialty ,Polyclonal hypergammaglobulinemia ,Disease ,Gastroenterology ,White People ,Autoimmune Diseases ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Asian People ,Interquartile range ,Internal medicine ,parasitic diseases ,Ethnicity ,Humans ,Medicine ,Eosinophilia ,Aged ,Retrospective Studies ,Total protein ,030203 arthritis & rheumatology ,integumentary system ,business.industry ,fungi ,Reproducibility of Results ,Retrospective cohort study ,Hispanic or Latino ,General Medicine ,Middle Aged ,Multiethnic population ,Arabs ,Immunoglobulin G ,030220 oncology & carcinogenesis ,Immunology ,Female ,medicine.symptom ,business ,Biomarkers ,Cohort study - Abstract
Background IgG4-related disease (IgG4-RD) is a recently recognized condition defined by characteristic histopathologic findings in affected organs. Serum IgG4 concentration is often but not always elevated. The sensitivity and specificity of serum IgG4 vary greatly across studies and has been anecdotally associated to ethnicity. Our study was conducted to investigate the difference in serum IgG4 levels between Asian and non-Asian patients with IgG4-RD. Methods This is a single-center retrospective study of 26 Asian and 10 non-Asian patients with histologically confirmed IgG4-RD. Serum IgG4 levels, clinical features and other laboratory findings were compared between the 2 groups, 31 Asian and 11 non-Asian patients with non-IgG4-RD rheumatic diseases were randomly identified to evaluate test characteristics of serum IgG4 measurement. Results Median serum IgG4 at time of diagnosis was significantly higher in Asian (median = 11.2 g/L, interquartile range: 4.6-19.7) than non-Asian patients (median = 2.9 g/L, interquartile range: 0.7-5.4, P = 0.0094), as well as the median serum IgG and total protein. Asian patients had more eosinophilia and polyclonal hypergammaglobulinemia than non-Asian patients ( P = 0.016 and 0.001, respectively). Test sensitivity was higher in Asian (96%) than non-Asian patients (67%), whereas test specificity was higher in non-Asian patients (91% versus 71%). Conclusion Asian patients with IgG4-RD have more exuberant serum IgG4, IgG and polyclonal hypergammaglobulinemia than non-Asian patients; the mechanism of this difference requires further study. These findings have significant clinical importance and must be accounted for in the diagnostic workup of patients in multiethnic settings.
- Published
- 2018
32. Mechanistic insights into how CMG helicase facilitates replication past DNA roadblocks
- Author
-
Michael M. Seidman, Michael A. Trakselis, and Robert M. Brosh
- Subjects
DNA Replication ,0301 basic medicine ,DNA damage ,DNA replisome ,Computer security ,computer.software_genre ,Biochemistry ,DNA Adducts ,03 medical and health sciences ,chemistry.chemical_compound ,Animals ,Humans ,Molecular Biology ,Genetics ,Copying ,Bacteria ,biology ,DNA synthesis ,DNA Helicases ,DNA replication ,Eukaryota ,Helicase ,DNA ,Cell Biology ,Replication (computing) ,030104 developmental biology ,chemistry ,biology.protein ,computer - Abstract
Before leaving the house, it is a good idea to check for road closures that may affect the morning commute. Otherwise, one may encounter significant delays arriving at the destination. While this is commonly true, motorists may be able to consult a live interactive traffic map and pick an alternate route or detour to avoid being late. However, this is not the case if one needs to catch the train which follows a single track to the terminus; if something blocks the track, there is a delay. Such is the case for the DNA replisome responsible for copying the genetic information that provides the recipe of life. When the replication machinery encounters a DNA roadblock, the outcome can be devastating if the obstacle is not overcome in an efficient manner. Fortunately, the cell's DNA synthesis apparatus can bypass certain DNA obstructions, but the mechanism(s) are still poorly understood. Very recently, two papers from the O'Donnell lab, one structural (Georgescu et al., 2017 [1]) and the other biochemical (Langston and O'Donnell, 2017 [2]), have challenged the conventional thinking of how the replicative CMG helicase is arranged on DNA, unwinds double-stranded DNA, and handles barricades in its path. These new findings raise important questions in the search for mechanistic insights into how DNA is copied, particularly when the replication machinery encounters a roadblock.
- Published
- 2017
33. Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo (Update) Executive Summary
- Author
-
Hussam K. El-Kashlan, Richard W. Waguespack, Terry D. Fife, Seth R. Schwartz, Courtney C. J. Voelker, Neil Bhattacharyya, Deena B Hollingsworth, Betty Tsai Do, Richard Roberts, Janene M Holmberg, Samuel P. Gubbels, Maureen D. Corrigan, Robert William Prasaad Steiner, Jonathan A. Edlow, Michael D. Seidman, and Kathryn Mahoney
- Subjects
Adult ,medicine.medical_specialty ,Benign paroxysmal positional vertigo ,Executive summary ,business.industry ,Alternative medicine ,Guideline ,medicine.disease ,Clinical trial ,Clinical Practice ,03 medical and health sciences ,0302 clinical medicine ,Systematic review ,Otorhinolaryngology ,medicine ,Physical therapy ,Humans ,Surgery ,Guideline development ,Benign Paroxysmal Positional Vertigo ,030223 otorhinolaryngology ,Intensive care medicine ,business ,Algorithms ,030217 neurology & neurosurgery - Abstract
The American Academy of Otolaryngology-Head and Neck Surgery Foundation has published a supplement to this issue of Otolaryngology-Head and Neck Surgery featuring the "Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo (Update)." To assist in implementing the guideline recommendations, this article summarizes the rationale, purpose, and key action statements. The 14 recommendations developed emphasize diagnostic accuracy and efficiency, reducing the inappropriate use of vestibular suppressant medications, decreasing the inappropriate use of ancillary testing, and increasing the appropriate therapeutic repositioning maneuvers. An updated guideline is needed due to new clinical trials, new systematic reviews, and the lack of consumer participation in the initial guideline development group.
- Published
- 2017
34. IgG4-related disease and lymphocyte-variant hypereosinophilic syndrome: A comparative case series
- Author
-
David F. Schaeffer, Andre Mattman, Michael A. Seidman, Jan P. Dutz, Fergal Donnellan, Vladimir Marquez, Mollie N. Carruthers, Joanna K. Law, Sujin Park, Luke Y.C. Chen, Bakul I. Dalal, Patrick Wong, Graham W. Slack, and Brian Skinnider
- Subjects
Adult ,Male ,medicine.medical_specialty ,T-Lymphocytes ,Lymphocyte ,Immunoglobulin E ,Gastroenterology ,Polyethylene Glycols ,03 medical and health sciences ,0302 clinical medicine ,Adrenal Cortex Hormones ,Internal medicine ,Hypereosinophilic Syndrome ,parasitic diseases ,medicine ,Humans ,Eosinophilia ,Aged ,integumentary system ,biology ,business.industry ,Hypereosinophilic syndrome ,Hypergammaglobulinemia ,Interferon-alpha ,Hematology ,General Medicine ,Middle Aged ,Eosinophil ,medicine.disease ,Recombinant Proteins ,medicine.anatomical_structure ,Immunoglobulin G ,030220 oncology & carcinogenesis ,biology.protein ,Female ,Rituximab ,IgG4-related disease ,medicine.symptom ,business ,030215 immunology ,medicine.drug - Abstract
OBJECTIVE To compare the clinical and laboratory features of IgG4-related disease (IgG4-RD) and lymphocyte-variant hypereosinophilic syndrome (L-HES), two rare diseases that often present with lymphadenopathy, gastrointestinal symptoms, eosinophilia, and elevated immunoglobulins/IgE. METHOD Comparative case series of 31 patients with IgG4-RD and 13 patients with L-HES. RESULTS Peripheral blood eosinophilia was present in eight of 31 patients with IgG4-RD compared to 13 of 13 patients with L-HES (median eosinophils 0.4 vs 7.0 giga/L, P=.001) and 12 of 20 patients with IgG4-RD had increased serum IgE compared to eight of 13 patients with L-HES, P=.930. Twenty-seven of 30 patients with IgG4-RD had elevated serum IgG4 compared to five of 12 patients with L-HES (median IgG4 9.6 g/L vs 0.80 g/L, P=.002). Flow cytometry demonstrated an aberrant T-cell phenotype in 7 of 23 patients with IgG4-RD and 13 of 13 patients with L-HES (P
- Published
- 2017
35. Totally Implantable Active Middle Ear Implants
- Author
-
Jack A. Shohet, Tyler A. Janz, and Michael D. Seidman
- Subjects
Moderate to severe ,medicine.medical_specialty ,Hearing loss ,Hearing Loss, Sensorineural ,Audiology ,Prosthesis Design ,Prosthesis Implantation ,03 medical and health sciences ,0302 clinical medicine ,Hearing Aids ,otorhinolaryngologic diseases ,medicine ,Humans ,030223 otorhinolaryngology ,business.industry ,General Medicine ,respiratory system ,medicine.disease ,United States ,Ossicular Prosthesis ,medicine.anatomical_structure ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Middle ear ,Sensorineural hearing loss ,medicine.symptom ,business ,Speech discrimination score - Abstract
The Envoy Esteem and the Carina system are the 2 totally implantable hearing devices. The Esteem is designed for patients with bilateral moderate to severe sensorineural hearing loss who have an unaided speech discrimination score of greater than and equal to 40%. The Carina system is designed for patients with moderate to severe sensorineural hearing loss or those with mixed hearing loss. The Esteem offers a technologically advanced method to provide improvements in hearing and is available in the United States, whereas the Carina system is currently not available in the United States.
- Published
- 2019
36. Polyarteritis nodosa isolated to the testis and urinary bladder in the setting of cryptorchidism: a case report and literature review
- Author
-
Natasha Dehghan, Greg Marcotte, Michael A. Seidman, and Mohan Stewart
- Subjects
Male ,medicine.medical_specialty ,Bladder ,Urinary Bladder ,lcsh:Medicine ,Case Report ,Disease ,030204 cardiovascular system & hematology ,Gross hematuria ,Resection ,03 medical and health sciences ,0302 clinical medicine ,Surgical oncology ,Cryptorchidism ,Testis ,Medicine ,Humans ,Urinary bladder ,business.industry ,Polyarteritis nodosa ,lcsh:R ,Urinary Bladder Diseases ,General Medicine ,Middle Aged ,medicine.disease ,Surgery ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,business ,Vasculitis ,Single organ vasculitis ,Orchiectomy ,Systemic vasculitis - Abstract
Background Polyarteritis nodosa is a small vessel to medium vessel vasculitis that frequently presents with multi-organ involvement, but can sometimes be limited to single organs such as the testes. Patients often require treatment with glucocorticoids, plus or minus additional immunosuppressive therapy depending on the severity of the disease. We describe a rare case of polyarteritis nodosa involving the right testis and urinary bladder without other systemic features of vasculitis. Case presentation A previously healthy 54-year-old First Nations Canadian man presented with intermittent gross hematuria. He underwent surgical excision of his right testis for cryptorchidism and a transurethral resection of a bladder mass. Histology showed an active medium vessel vasculitis in both organs. On extensive clinical, laboratory, and radiographic review, he had no systemic features of vasculitis. On 2-year follow-up, he has not required any systemic therapy and has not developed further symptoms. Conclusion Single organ polyarteritis nodosa can sometimes be managed with surgical excision of the involved organ alone. Although our patient had two organs involved, we extrapolated the results of our literature search to guide his care. This case highlights the potential for surgical excision to cure polyarteritis nodosa despite the involvement of two organs in the absence of symptoms and signs of systemic vasculitis.
- Published
- 2019
37. EXD2 Protects Stressed Replication Forks and Is Required for Cell Viability in the Absence of BRCA1/2
- Author
-
Jadwiga, Nieminuszczy, Ronan, Broderick, Marina A, Bellani, Elizabeth, Smethurst, Rebekka A, Schwab, Veronica, Cherdyntseva, Theodora, Evmorfopoulou, Yea-Lih, Lin, Michal, Minczuk, Philippe, Pasero, Sarantis, Gagos, Michael M, Seidman, and Wojciech, Niedzwiedz
- Subjects
BRCA2 Protein ,DNA Replication ,RecQ Helicases ,BRCA1 Protein ,DNA Helicases ,BRCA1 ,EXDL2 ,BRCA2 ,Genomic Instability ,Article ,Exodeoxyribonucleases ,Neoplasms ,Humans ,EXD2 ,fork regression ,Synthetic Lethal Mutations ,HeLa Cells - Abstract
Summary Accurate DNA replication is essential to preserve genomic integrity and prevent chromosomal instability-associated diseases including cancer. Key to this process is the cells’ ability to stabilize and restart stalled replication forks. Here, we show that the EXD2 nuclease is essential to this process. EXD2 recruitment to stressed forks suppresses their degradation by restraining excessive fork regression. Accordingly, EXD2 deficiency leads to fork collapse, hypersensitivity to replication inhibitors, and genomic instability. Impeding fork regression by inactivation of SMARCAL1 or removal of RECQ1’s inhibition in EXD2−/− cells restores efficient fork restart and genome stability. Moreover, purified EXD2 efficiently processes substrates mimicking regressed forks. Thus, this work identifies a mechanism underpinned by EXD2’s nuclease activity, by which cells balance fork regression with fork restoration to maintain genome stability. Interestingly, from a clinical perspective, we discover that EXD2’s depletion is synthetic lethal with mutations in BRCA1/2, implying a non-redundant role in replication fork protection., Graphical Abstract, Highlights • EXD2 is required for cell survival in response to replicative stress • EXD2 protects replication forks from over resection by counteracting fork reversal • EXD2 is synthetic lethal with the deficiency in BRCA1/2 genes, Nieminuszczy et al. identify a key function of the EXD2 nuclease in DNA replication and alternative end-joining. EXD2 localizes to replication forks and promotes their stabilization by counteracting fork regression. Loss of EXD2 results in sensitivity to replicative inhibitors, degradation of regressed forks, and compromises survival of BRCA1/2-deficient tumors.
- Published
- 2018
38. Granzyme B Deficiency Protects against Angiotensin II Induced Cardiac Fibrosis
- Author
-
Yue Shen, Tatjana Bozin, Lubos Bohunek, John E. Eriksson, Lisa S. Ang, Yulia Merkulova, Ivy Hsu, Fang Cheng, David J. Granville, Kathryn Westendorf, Bruce M. McManus, Sheetal A. Raithatha, Sarah J. Williams, Hongyan Zhao, Michael A. Seidman, Leigh G. Parkinson, Mehul Sharma, and R. Chris Bleackley
- Subjects
Adult ,Male ,0301 basic medicine ,Heart Diseases ,Cardiac fibrosis ,Fluorescent Antibody Technique ,Inflammation ,Biology ,Real-Time Polymerase Chain Reaction ,ta3111 ,Granzymes ,Pathology and Forensic Medicine ,GZMB ,Mice ,Young Adult ,03 medical and health sciences ,Fibrosis ,medicine ,Animals ,Humans ,Aged ,Mice, Knockout ,Middle Aged ,medicine.disease ,Immunohistochemistry ,Angiotensin II ,3. Good health ,Mice, Inbred C57BL ,Granzyme B ,Disease Models, Animal ,030104 developmental biology ,Granzyme ,Perforin ,Immunology ,biology.protein ,Female ,medicine.symptom - Abstract
Cardiac fibrosis is observed across diverse etiologies of heart failure. Granzyme B (GzmB) is a serine protease involved in cell-mediated cytotoxicity in conjunction with the pore-forming protein, perforin. Recent evidence suggests that GzmB also contributes to matrix remodeling and fibrosis through an extracellular, perforin-independent process. However, the role of GzmB in the onset and progression of cardiac fibrosis remains elusive. The present study investigated the role of GzmB in the pathogenesis of cardiac fibrosis. GzmB was elevated in fibrotic human hearts and in angiotensin II–induced murine cardiac fibrosis. Genetic deficiency of GzmB reduced angiotensin II–induced cardiac hypertrophy and fibrosis, independently of perforin. GzmB deficiency also reduced microhemorrhage, inflammation, and fibroblast accumulation in vivo . In vitro , GzmB cleaved the endothelial junction protein, vascular endothelial (VE)-cadherin, resulting in the disruption of endothelial barrier function. Together, these results suggest a perforin-independent, extracellular role for GzmB in the pathogenesis of cardiac fibrosis.
- Published
- 2016
39. IgG4-related disease: what a hematologist needs to know
- Author
-
Luke Y.C. Chen, Andre Mattman, Michael A. Seidman, and Mollie N. Carruthers
- Subjects
Diagnostic Imaging ,Male ,Pathology ,medicine.medical_specialty ,Biopsy ,Disease ,Review Article ,Retroperitoneal fibrosis ,Diagnosis, Differential ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Eosinophilia ,Humans ,Autoimmune pancreatitis ,Aged, 80 and over ,business.industry ,Disease Management ,Hematology ,Plasma cell neoplasm ,medicine.disease ,Combined Modality Therapy ,Lymphoma ,Phenotype ,Treatment Outcome ,IgG4-related disease ,Rituximab ,Disease Susceptibility ,Immunoglobulin G4-Related Disease ,medicine.symptom ,Symptom Assessment ,business ,Biomarkers ,030215 immunology ,medicine.drug - Abstract
IgG4-related disease is a fibro-inflammatory condition that can affect nearly any organ system. Common presentations include major salivary and lacrimal gland enlargement, orbital disease, autoimmune pancreatitis, retroperitoneal fibrosis and tubulointerstitial nephritis. This review focuses on the hematologic manifestations of IgG4-related disease, including lymphadenopathy, eosinophilia, and polyclonal hypergammaglobulinemia. The disease can easily be missed by unsuspecting hematologists, as patients may present with clinical problems that mimic disorders such as multicentric Castleman disease, lymphoma, plasma cell neoplasms and hypereosinophilic syndromes. When IgG4-related disease is suspected, serum protein electrophoresis and IgG subclasses are helpful as initial tests but a firm histological diagnosis is essential both to confirm the diagnosis and to rule out mimickers. The central histopathological features are a dense, polyclonal, lymphoplasmacytic infiltrate enriched with IgG4-positive plasma cells (with an IgG4/IgG ratio >40%), storiform fibrosis, and obliterative phlebitis. Importantly for hematologists, the latter two features are seen in all tissues except bone marrow and lymph nodes, making these two sites suboptimal for histological confirmation. Many patients follow an indolent course and respond well to treatment, but a significant proportion may have highly morbid or fatal complications such as periaortitis, severe retroperitoneal fibrosis or pachymeningitis. Corticosteroids are effective but cause new or worsening diabetes in about 40% of patients. Initial response rates to rituximab are high but durable remissions are rare. More intensive lymphoma chemotherapy regimens may be required in rare cases of severe, refractory disease, and targeted therapy against plasmablasts, IgE and other disease biomarkers warrant further exploration.
- Published
- 2018
40. Transcatheter Aortic Heart Valves: Histological Analysis Providing Insight to Leaflet Thickening and Structural Valve Degeneration
- Author
-
Stephanie L, Sellers, Christopher T, Turner, Janarthanan, Sathananthan, Timothy R G, Cartlidge, Frances, Sin, Rihab, Bouchareb, John, Mooney, Bjarne L, Nørgaard, Jeroen J, Bax, Pascal N, Bernatchez, Marc R, Dweck, David J, Granville, David E, Newby, Sandra, Lauck, John G, Webb, Geoffrey W, Payne, Philippe, Pibarot, Philipp, Blanke, Michael A, Seidman, and Jonathon A, Leipsic
- Subjects
Aged, 80 and over ,Male ,Time Factors ,Calcinosis ,Endothelial Cells ,Thrombosis ,Prosthesis Design ,Fibrosis ,Prosthesis Failure ,Transcatheter Aortic Valve Replacement ,Treatment Outcome ,Aortic Valve ,Heart Valve Prosthesis ,Humans ,Female ,Registries ,Matrix Metalloproteinase 1 ,Device Removal ,Aged ,Retrospective Studies - Abstract
This study investigated processes causing leaflet thickening and structural valve degeneration (SVD).Although transcatheter aortic valve replacement (TAVR) has changed the treatment of aortic stenosis, concerns remain regarding SVD, potentially related to valve thrombosis and thickening, based on studies using computed tomography (CT). Detailed histological analyses are provided to help attain insights into these processes.Explanted transcatheter heart valves (THVs) were evaluated for thrombosis, fibrosis, and calcification for quantification of leaflet thickness. Immunohistochemical and microscopy approaches were used to investigate SVD-associated mechanisms.THVs (n = 23) were obtained from 22 patients (median 81 years of age; 50% male) from 0 to 2,583 days post TAVR. Maximal leaflet thickness increased relative to implant duration (ρ = 0.427; p = 0.027). THVs explanted after2 years were thicker than those explanted after 2 years (p = 0.007). All THVs had adherent thrombus on both aortic and ventricular sides, which beyond 60 days was seen in combination with fibrosis and beyond 4 years had calcification. Early thrombus formation (60 days) occurred despite rapid endothelialization with an abnormal hyperplastic phenotype. Fibrosis was observed in 6 patients on both the aortic and the ventricular THV surfaces, remodeled over time, and was associated with matrix metalloproteinase-1 expression. Five THVs showed overt calcification associated with adherent thrombus and fibrosis.There is a time-dependent degeneration of THVs consisting of thrombus formation, endothelial hyperplasia, fibrosis, tissue remodeling, proteinase expression, and calcification. Future investigation is needed to further understand these mechanisms contributing to leaflet thickening and SVD.
- Published
- 2018
41. Genes in the Basement, Postmortem Genetic Testing…and 3 (New) Realities
- Author
-
Richard N. Mitchell and Michael A. Seidman
- Subjects
History ,030204 cardiovascular system & hematology ,Disease pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,Formaldehyde ,Genetics ,medicine ,Retrospective analysis ,Humans ,030212 general & internal medicine ,Paraffin embedding ,Genetic Testing ,Death sudden cardiac ,Genetics (clinical) ,Genetic testing ,Paraffin Embedding ,medicine.diagnostic_test ,High-Throughput Nucleotide Sequencing ,Genomics ,humanities ,Genealogy ,Peripheral blood ,Death, Sudden, Cardiac ,Treasure ,Cardiology and Cardiovascular Medicine - Abstract
We all have a treasure trove of things—squirreled away in knick-knack drawers or long-forgotten boxes in the basement, storage lockers, and parents’ homes. Things we tell ourselves will someday have value if we just wait long enough. Every pathology department has things too—the glass slides and paraffin blocks of specimens long since diagnosed and discarded, all tucked away in the far recesses of hospitals and storage warehouses, waiting for a time to reach their full potential. A select few of these even manage to be resurrected each year, some for a retrospective analysis of one marker or another, others to settle a diagnostic or medicolegal matter. Most, however, sit idly in file cabinets and storage facilities, out of sight and largely forgotten, reminiscent of the final scene in Raiders of the Lost Ark. See Article by Baudhuin et al Those materials, however, still have great value. Among pathologists, this is not exactly a secret—archived slides and blocks have long been appropriated for developing new stains, defining diagnoses, and understanding disease pathogenesis. And when modern genetic testing methods arrived, many had visions of Jurassic Park-style moments, unlocking the secrets embedded not in amber but in paraffin. Unfortunately, most of the promise of such materials has languished. Genetic testing methods to date have largely focused on peripheral blood and carefully preserved tissues gathered from living patients. Applying the same techniques to the stuff …
- Published
- 2017
42. Catalytic Strand Separation by RECQ1 Is Required for RPA-Mediated Response to Replication Stress
- Author
-
Michael M. Seidman, Taraswi Banerjee, Robert M. Brosh, Joshua A. Sommers, and Jing Huang
- Subjects
DNA Replication ,Genome instability ,DNA Repair ,DNA repair ,DNA damage ,RecQ helicase ,Genomic Instability ,Article ,General Biochemistry, Genetics and Molecular Biology ,Substrate Specificity ,Stress, Physiological ,Cell Line, Tumor ,Replication Protein A ,Humans ,Replication protein A ,Cells, Cultured ,RecQ Helicases ,Agricultural and Biological Sciences(all) ,biology ,Biochemistry, Genetics and Molecular Biology(all) ,DNA replication ,Helicase ,DNA ,Molecular biology ,Branch migration ,Protein Structure, Tertiary ,enzymes and coenzymes (carbohydrates) ,biology.protein ,General Agricultural and Biological Sciences ,DNA Damage ,Protein Binding - Abstract
SummaryThree (BLM, WRN, and RECQ4) of the five human RecQ helicases are linked to genetic disorders characterized by genomic instability, cancer, and accelerated aging [1]. RECQ1, the first human RecQ helicase discovered [2–4] and the most abundant [5], was recently implicated in breast cancer [6, 7]. RECQ1 is an ATP-dependent DNA-unwinding enzyme (helicase) [8, 9] with roles in replication [10–12] and DNA repair [13–16]. RECQ1 is highly expressed in various tumors and cancer cell lines (for review, see [17]), and its suppression reduces cancer cell proliferation [14], suggesting a target for anti-cancer drugs. RECQ1’s assembly state plays a critical role in modulating its helicase, branch migration (BM), or strand annealing [18, 19]. The crystal structure of truncated RECQ1 [20, 21] resembles that of E. coli RecQ [22] with two RecA-like domains, a RecQ-specific zinc-binding domain and a winged-helix domain, the latter implicated in DNA strand separation and oligomer formation. In addition, a conserved aromatic loop (AL) is important for DNA unwinding by bacterial RecQ [23, 24] and truncated RECQ1 helicases [21]. To better understand the roles of RECQ1, two AL mutants (W227A and F231A) in full-length RECQ1 were characterized biochemically and genetically. The RECQ1 mutants were defective in helicase or BM but retained DNA binding, oligomerization, ATPase, and strand annealing. RECQ1-depleted HeLa cells expressing either AL mutant displayed reduced replication tract length, elevated dormant origin firing, and increased double-strand breaks that could be suppressed by exogenously expressed replication protein A (RPA). Thus, RECQ1 governs RPA’s availability in order to maintain normal replication dynamics, suppress DNA damage, and preserve genome homeostasis.
- Published
- 2015
43. Current opinion
- Author
-
Syed F. Ahsan and Michael D. Seidman
- Subjects
medicine.medical_specialty ,business.industry ,MEDLINE ,Chronic tinnitus ,Disease Management ,Treatment options ,Tinnitus ,Chronic disease ,Otorhinolaryngology ,Chronic Disease ,otorhinolaryngologic diseases ,medicine ,Humans ,Surgery ,medicine.symptom ,Disease management (health) ,Psychiatry ,business - Abstract
The purpose of this review is to describe our experience with management of chronic tinnitus and to review the recent literature on the best treatment options available for treating patients who are troubled by their tinnitus. In addition, we want to highlight our experience and approach to this very common problem.Treatment options for patients are based on the severity of the tinnitus and any associated problems. The use of nutritional supplements has a place in the treatment of mild-to-moderate tinnitus. Ginkgo biloba and B-complex vitamins may have an impact on selected patients. Treatment of underlying or accompanying anxiety disorders especially with cognitive behavior therapy can help to reduce the distress associated with tinnitus. Surgical treatment options, such as cochlear implant, have been shown to be very effective in reducing tinnitus in patients with sudden unilateral hearing loss as the cause of tinnitus. Other surgical approaches, such as repetitive transcranial magnetic stimulation and vagal stimulator, have had some limited benefits.Treatment for subjective tinnitus can range from the conventional to the investigational modalities. Best treatment options take into account the possible cause of the tinnitus and other associated symptoms.
- Published
- 2015
44. Acupuncture and allergic rhinitis
- Author
-
William D. Reddy, Malcolm B. Taw, Folashade Omole, and Michael D. Seidman
- Subjects
medicine.medical_specialty ,Modalities ,business.industry ,Acupuncture Therapy ,MEDLINE ,Rhinitis, Allergic ,Quality-adjusted life year ,Quality of life (healthcare) ,Otorhinolaryngology ,Quality of Life ,Acupuncture ,medicine ,Humans ,Surgery ,Quality-Adjusted Life Years ,Intensive care medicine ,business - Abstract
Allergic rhinitis has a high prevalence and negatively impacts quality of life. Patients commonly use complementary and integrative modalities to help alleviate their symptoms of allergic rhinitis, with approximately one in five receiving acupuncture. This article reviews the evidence base on the efficacy/effectiveness, safety and cost-effectiveness of acupuncture for allergic rhinitis.Our review of the medical literature from January 2013 through December 2014 revealed that there is research demonstrating efficacy and effectiveness for acupuncture in the treatment of allergic rhinitis, as well as improvement of quality of life and quality-adjusted life-years.There are high-quality randomized controlled trials that demonstrate efficacy and effectiveness for acupuncture in the treatment of both seasonal and perennial allergic rhinitis. Smaller head-to-head studies also show some preliminary benefit of acupuncture when compared with antihistamines, but these had a variety of methodological limitations. Further studies of higher quality are needed, particularly with a focus on comparative effectiveness research.
- Published
- 2015
45. Integrative medical approaches to allergic rhinitis
- Author
-
Michael D. Seidman, William D. Reddy, Folashade Omole, and Benjamin F. Asher
- Subjects
Complementary Therapies ,medicine.medical_specialty ,Extramural ,business.industry ,Alternative medicine ,MEDLINE ,Placebo ,Rhinitis, Allergic ,Otorhinolaryngology ,Allergic symptoms ,medicine ,Humans ,Surgery ,Integrative medicine ,Intensive care medicine ,business - Abstract
Purpose of review Complementary and integrative medicine (CIM), formerly known as alternative medicine, is now part of the mainstream management for patients with a host of medical issues. This current opinion focuses on the use of CIM, more specifically, the use of nutritional and herbal therapies and homeopathic medications for patients with allergic symptoms. Recent findings The literature review revealed that naturally occurring substances when compared with placebo more often than not resulted in significant improvement of the allergic rhinitis symptoms. Summary Despite encouraging results, additional studies with greater rigor are needed.
- Published
- 2015
46. UHRF1 Contributes to DNA Damage Repair as a Lesion Recognition Factor and Nuclease Scaffold
- Author
-
Gargi Ghosal, Junjie Chen, Manikandan Paramasivam, Yaling Huang, Yanyan Tian, Xi Shen, Randy J. Legerski, Michael M. Seidman, Ding Chen, Shamima Akhter, Lei Li, and Jun Qin
- Subjects
DNA Repair ,HMG-box ,DNA damage ,DNA repair ,Ubiquitin-Protein Ligases ,Biology ,Article ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,0302 clinical medicine ,Humans ,Protein–DNA interaction ,lcsh:QH301-705.5 ,Replication protein A ,030304 developmental biology ,0303 health sciences ,Ubiquitin ,DNA ,Endonucleases ,Molecular biology ,Proliferating cell nuclear antigen ,Fanconi Anemia ,lcsh:Biology (General) ,030220 oncology & carcinogenesis ,CCAAT-Enhancer-Binding Proteins ,biology.protein ,DNA mismatch repair ,DNA Damage ,Nucleotide excision repair - Abstract
SummaryWe identified ubiquitin-like with PHD and RING finger domain 1 (UHRF1) as a binding factor for DNA interstrand crosslink (ICL) lesions through affinity purification of ICL-recognition activities. UHRF1 is recruited to DNA lesions in vivo and binds directly to ICL-containing DNA. UHRF1-deficient cells display increased sensitivity to a variety of DNA damages. We found that loss of UHRF1 led to retarded lesion processing and reduced recruitment of ICL repair nucleases to the site of DNA damage. UHRF1 interacts physically with both ERCC1 and MUS81, two nucleases involved in the repair of ICL lesions. Depletion of both UHRF1 and components of the Fanconi anemia (FA) pathway resulted in increased DNA damage sensitivity compared to defect of each mechanism alone. These results suggest that UHRF1 promotes recruitment of lesion-processing activities via its affinity to recognize DNA damage and functions as a nuclease recruitment scaffold in parallel to the FA pathway.
- Published
- 2015
47. Clinical Practice Guideline
- Author
-
Seth R. Schwartz, Sonya Malekzadeh, Joseph K. Han, James R. Bonner, Stacey L. Ishman, Fuad M. Baroody, Meghan N. Wilson, William D. Reddy, Sandra Y. Lin, Sandra A. Walsh, Jesse M. Hackell, Lorraine C. Nnacheta, Mark S. Dykewicz, Folashade Omole, Richard K. Gurgel, James W. Mims, Barbara E Warren, Michael D. Seidman, Douglas E Dawson, Helene J. Krouse, and Dana V. Wallace
- Subjects
medicine.medical_specialty ,Allergy ,Executive summary ,business.industry ,Alternative medicine ,Psychological intervention ,Comorbidity ,Guideline ,Nasal congestion ,medicine.disease ,Rhinitis, Allergic ,United States ,Documentation ,Quality of life (healthcare) ,Otorhinolaryngology ,Quality of Life ,medicine ,Physical therapy ,Humans ,Surgery ,medicine.symptom ,Intensive care medicine ,business - Abstract
The American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF) has published a supplement to this issue featuring the new Clinical Practice Guideline: Allergic Rhinitis. To assist in implementing the guideline recommendations, this article summarizes the rationale, purpose, and key action statements. The 14 recommendations developed address the evaluation of patients with allergic rhinitis, including performing and interpretation of diagnostic testing and assessment and documentation of chronic conditions and comorbidities. It will then focus on the recommendations to guide the evaluation and treatment of patients with allergic rhinitis, to determine the most appropriate interventions to improve symptoms and quality of life for patients with allergic rhinitis.
- Published
- 2015
48. Coronary lumen volume to myocardial mass ratio in primary microvascular angina
- Author
-
Rominder Grover, Bjarne L. Nørgaard, Jonathon Leipsic, Stephanie L. Sellers, Jeroen J. Bax, Michael A. Seidman, Darra T. Murphy, Ashkan Eftekhari, John Mooney, Mickaël Ohana, Shaw-Hua Kueh, Cameron J. Hague, Tara Sedlak, and Philipp Blanke
- Subjects
Male ,Computed Tomography Angiography ,Fractional flow reserve ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,Coronary Angiography ,030218 nuclear medicine & medical imaging ,Angina ,Coronary artery disease ,0302 clinical medicine ,Computed tomography angiography ,medicine.diagnostic_test ,Middle Aged ,Prognosis ,Coronary Vessels ,Plaque, Atherosclerotic ,Fractional Flow Reserve, Myocardial ,medicine.anatomical_structure ,Predictive value of tests ,Area Under Curve ,Cardiology ,Radiographic Image Interpretation, Computer-Assisted ,Female ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,Adult ,medicine.medical_specialty ,Asymptomatic ,03 medical and health sciences ,Coronary circulation ,Microvascular angina ,Predictive Value of Tests ,Internal medicine ,Multidetector Computed Tomography ,medicine ,Journal Article ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Retrospective Studies ,business.industry ,Myocardium ,Reproducibility of Results ,CTCA ,medicine.disease ,Atherosclerosis ,Coronary arteries ,ROC Curve ,FFRCT ,business - Abstract
BACKGROUND: Microvascular angina (MVA) is an incompletely understood clinical entity. Computational analysis of coronary Computed Tomography Angiography (CTA) has shown an association between low coronary lumen volume to myocardial mass (V/M) ratio and lower Fractional Flow Reserve values, independent of plaque measures. We hypothesized that low V/M ratio may be present in patients with MVA.METHODS: A retrospective case-control analysis was performed using patients fulfilling guideline criteria for MVA with controls matched for age, gender, coronary risk factors and atherosclerotic plaque burden. V/M was extracted off site (Heartflow Inc; Redwood City, CA) employing allometric scaling laws that allow the definition of the coronary circulation beyond the epicardium. FFRCT values were calculated in the major epicardial coronary arteries for each group.RESULTS: A total of 30 patients with MVA and 32 matched controls were included in the study. Mean total coronary lumen volume (2302 mm(3) ± 109 vs 2978 mm(3) ± 134, p < 0.001) and mean myocardial mass (90.4 g ± 13.7 vs 100.4 g ± 20.1, p = 0.029) were lower in MVA patients compared to controls. Mean V/M ratio was significantly lower in MVA compared to controls (25.6 mm(3)/g ± 5.9 vs 30.0 mm(3)/g ± 6.5, p = 0.007; c-statistic 0.69). V/M ratio did not differ significantly between subclasses of angina severity (p = 0.747). No difference in mean nadir FFRCT values was found between MVA and control groups in the LAD (0.86 ± 0.07 vs 0.83 ± 0.07, p = 0.154), LCX (0.90 ± 0.05 vs 0.90 ± 0.06, p = 0.240) and RCA (0.90 ± 0.04 vs 0.90 ± 0.03, p = 0.773) vessels.CONCLUSION: Patients with microvascular angina demonstrate a significantly lower coronary CTA-derived coronary volume/myocardial mass ratio than asymptomatic controls.
- Published
- 2017
49. Long-term Hearing Preservation After Resection of Vestibular Schwannoma: A Systematic Review and Meta-analysis
- Author
-
Farhan S. Huq, Michael D. Seidman, Syed F. Ahsan, and Andrew Taylor
- Subjects
Adult ,Male ,medicine.medical_specialty ,Treatment outcome ,MEDLINE ,Audiology ,Schwannoma ,Cochrane Library ,Resection ,03 medical and health sciences ,0302 clinical medicine ,Hearing ,otorhinolaryngologic diseases ,Medicine ,Humans ,Postoperative Period ,030223 otorhinolaryngology ,Vestibular system ,Hearing preservation ,business.industry ,General surgery ,Neuroma, Acoustic ,Middle Aged ,medicine.disease ,Sensory Systems ,Treatment Outcome ,Otorhinolaryngology ,Meta-analysis ,Female ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
The objective is to perform a systematic review and meta-analysis of the literature on the long-term results of hearing preservation after vestibular schwannoma resection.Ovid/Medline, PubMed, Embase, and the Cochrane library from January 1980 to January 2015.Inclusion criteria: age ≥18 years, minimum 10 patients in the treatment group, hearing preserving microsurgery, no previous radiation treatment, serviceable hearing at immediate postop follow-up, hearing outcomes reported using Gardner Robinson or the American Academy of Otolaryngology-Head and Neck Surgeons hearing grading scales, and average follow-up of 5 years. Preoperative, immediate postoperative, and last follow-up audiograms were required. Exclusion criteria included neurofibromatosis type 2 patients and surgery for salvage therapy or decompression.Quality evaluated using Methodological Index for Non-Randomized Studies.Meta-analysis was performed using R v3.2.2, Metafor package v 1.9-7. Cohen's D was used to determine effect size. Ten reports had at least 5-year follow-up and used standardized hearing grading scales. The systematic review found that if hearing was preserved at Class A or B at early postop visit, the chance of preserving hearing at 5 years was excellent. Those who maintained speech discrimination score ≥ 89% at the early postoperative follow-up had better long-term hearing preservation. The meta-analysis reveals that only preoperative and postoperative pure-tone average was associated with long-term hearing preservation.Long-term (5 yr) hearing durability rates are generally very good. Most studies do not report patient and tumor characteristics, therefore precluding combining studies for meta-analysis. Only preoperative and postoperative postoperative pure-tone average was associated with long-term hearing durability.
- Published
- 2017
50. Evaluation of Noise Exposure Secondary to Wind Noise in Cyclists
- Author
-
Syed F Ahsan, Michael D Seidman, Anna G. Wertz, Matthew M Smith, and Steve Jacob
- Subjects
Adult ,Male ,medicine.medical_specialty ,Acoustics ,Airflow ,Wind ,Audiology ,Loudness ,Ion wind ,03 medical and health sciences ,Sound exposure ,0302 clinical medicine ,Medicine ,Humans ,030212 general & internal medicine ,030223 otorhinolaryngology ,Sound pressure ,Wind tunnel ,business.industry ,Audiogram ,Bicycling ,Noise ,Otorhinolaryngology ,Hearing Loss, Noise-Induced ,Surgery ,business - Abstract
Objective Determine if the noise levels of wind exposure experienced by cyclists reach levels that could contribute to noise-induced hearing loss. Study Design Industrial lab research. Setting Industrial wind tunnel. Subjects and Methods A commercial-grade electric wind tunnel was used to simulate different speeds encountered by a cyclist. A single cyclist was used during the simulation for audiometric measurements. Microphones attached near the ears of the cyclist were used to measure the sound (dB sound pressure level) experienced by the cyclist. Loudness levels were measured with the head positioned at 15-degree increments from 0 degrees to 180 degrees relative to the oncoming wind at different speeds (10-60 mph). Results Wind noise ranged from 84.9 dB at 10 mph and increased proportionally with speed to a maximum of 120.3 dB at 60 mph. The maximum of 120.3 dB was measured at the downwind ear when the ear was 90 degrees away from the wind. Conclusions Wind noise experienced by a cyclist is proportional to the speed and the directionality of the wind current. Turbulent air flow patterns are observed that contribute to increased sound exposure in the downwind ear. Consideration of ear deflection equipment without compromising sound awareness for cyclists during prolonged rides is advised to avoid potential noise trauma. Future research is warranted and can include long-term studies including dosimetry measures of the sound and yearly pre- and postexposure audiograms of cyclists to detect if any hearing loss occurs with long-term cycling.
- Published
- 2017
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.