130 results on '"Newman SL"'
Search Results
2. Chronicling the Journey of the Society for the Advancement in Biology Education Research (SABER) in its Effort to Become Antiracist: From Acknowledgement to Action
- Author
-
Segura-Totten, M, Segura-Totten, M, Dewsbury, B, Lo, SM, Bailey, EG, Beaster-Jones, L, Bills, RJ, Brownell, SE, Caporale, N, Dunk, R, Eddy, SL, García-Ojeda, ME, Gardner, SM, Green, LE, Hartley, L, Harrison, C, Imad, M, Janosik, AM, Jeong, S, Josek, T, Kadandale, P, Knight, J, Ko, ME, Kukday, S, Lemons, P, Litster, M, Lom, B, Ludwig, P, McDonald, KK, McIntosh, ACS, Menezes, S, Nadile, EM, Newman, SL, Ochoa, SD, Olabisi, O, Owens, MT, Price, RM, Reid, JW, Ruggeri, N, Sabatier, C, Sabel, JL, Sato, BK, Smith-Keiling, BL, Tatapudy, SD, Theobald, EJ, Tripp, B, Pradhan, M, Venkatesh, MJ, Wilton, M, Warfa, AM, Wyatt, BN, Raut, SA, Segura-Totten, M, Segura-Totten, M, Dewsbury, B, Lo, SM, Bailey, EG, Beaster-Jones, L, Bills, RJ, Brownell, SE, Caporale, N, Dunk, R, Eddy, SL, García-Ojeda, ME, Gardner, SM, Green, LE, Hartley, L, Harrison, C, Imad, M, Janosik, AM, Jeong, S, Josek, T, Kadandale, P, Knight, J, Ko, ME, Kukday, S, Lemons, P, Litster, M, Lom, B, Ludwig, P, McDonald, KK, McIntosh, ACS, Menezes, S, Nadile, EM, Newman, SL, Ochoa, SD, Olabisi, O, Owens, MT, Price, RM, Reid, JW, Ruggeri, N, Sabatier, C, Sabel, JL, Sato, BK, Smith-Keiling, BL, Tatapudy, SD, Theobald, EJ, Tripp, B, Pradhan, M, Venkatesh, MJ, Wilton, M, Warfa, AM, Wyatt, BN, and Raut, SA
- Abstract
The tragic murder of Mr. George Floyd brought to the head long-standing issues of racial justice and equity in the United States and beyond. This prompted many institutions of higher education, including professional organizations and societies, to engage in long-overdue conversations about the role of scientific institutions in perpetuating racism. Similar to many professional societies and organizations, the Society for the Advancement of Biology Education Research (SABER), a leading international professional organization for discipline-based biology education researchers, has long struggled with a lack of representation of People of Color (POC) at all levels within the organization. The events surrounding Mr. Floyd’s death prompted the members of SABER to engage in conversations to promote self-reflection and discussion on how the society could become more antiracist and inclusive. These, in turn, resulted in several initiatives that led to concrete actions to support POC, increase their representation, and amplify their voices within SABER. These initiatives included: a self-study of SABER to determine challenges and identify ways to address them, a year-long seminar series focused on issues of social justice and inclusion, a special interest group to provide networking opportunities for POC and to center their voices, and an increase in the diversity of keynote speakers and seminar topics at SABER conferences. In this article, we chronicle the journey of SABER in its efforts to become more inclusive and antiracist. We are interested in increasing POC representation within our community and seek to bring our resources and scholarship to reimagine professional societies as catalyst agents towards an equitable antiracist experience. Specifically, we describe the 12 concrete actions that SABER enacted over a period of a year and the results from these actions so far. In addition, we discuss remaining challenges and future steps to continue to build a more welcomin
- Published
- 2021
3. Cell-mediated immunity to Histoplasma capsulatum1
- Author
-
Newman Sl
- Subjects
Microbiology (medical) ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,biology ,business.industry ,Intracellular parasite ,chemical and pharmacologic phenomena ,Fungus ,bacterial infections and mycoses ,biology.organism_classification ,Histoplasma capsulatum ,Cell mediated immunity ,Microbiology ,fluids and secretions ,Immunity ,Molecular genetics ,medicine ,business ,Pathogen - Abstract
Histoplasma capsulatum is a facultative intracellular pathogen, and the causative agent of the most common systemic fungal infection. Over the past several years, many new insights have been learned concerning the biology, biochemistry, and molecular genetics of this microorganism. This review focuses on the immunology of host defense against H. capsulatum yeasts with emphasis on the development of cell-mediated immunity, and the strategies used by the fungus to survive and multiply within macrophages.
- Published
- 2001
- Full Text
- View/download PDF
4. Inhibition of Growth of Histoplasma-capsulatum Yeast-cells in Human Macrophages By the Iron Chelator Vuf-8514 and Comparison of Vuf-8514 With Deferoxamine
- Author
-
UCL, Newman, SL., Gootee, L., Stroobant, Vincent, Vandergoot, H., Boelaert, JR., UCL, Newman, SL., Gootee, L., Stroobant, Vincent, Vandergoot, H., and Boelaert, JR.
- Abstract
Histoplasma capsulatum requires intracellular iron to survive and multiply within human and murine macrophages (M phi). Thus, iron chelators may be useful compounds in the treatment of histoplasmosis. In the present study we compared the efficacies of five different iron chelators with deferoxamine (DEF) for their capacity to inhibit the growth of H. capsulatum yeast cells in culture medium and within human M phi. Of the agents tested, only one, VUF 8514, a 2,2'-bipyridyl analog, was found to be effective. VUF 8514 inhibited the growth of yeast cells in tissue culture medium and within M phi in a dose-response fashion. In tissue culture medium, the 50% effective dose (ED(50)) of VUF 8514 was 30 nM and the ED(50) of DEF was 1 mM. In human M phi, the ED(50) of VUF 8514 was 520 nM and the ED(50) of DEF was 4 mM. Thus, VUF 8514 was effective at a concentration 7.7 x 10(3)-fold lower than DEF in inhibiting the growth of yeast cells in M phi. Inhibition of the intracellular growth of yeast cells by VUF 8514 was reversed by holotransferrin and iron nitriloacetate, an iron compound that is soluble at neutral to alkaline pH. Thus, VUF 8514 inhibits the intracellular growth of yeast cells by acting as an iron chelator rather than through its capacity as a weak base. These data suggest that the hydroxamic acid siderophore of H. capsulatum yeast cells competes successfully for iron against some iron chelators but not others and that VUF 8514 may be a potential therapeutic agent for the treatment of histoplasmosis.
- Published
- 1995
5. Digestion of histoplasma capsulatum yeasts by human macrophages
- Author
-
Newman, SL, primary, Gootee, L, additional, Morris, R, additional, and Bullock, WE, additional
- Published
- 1992
- Full Text
- View/download PDF
6. Preliminary experiences of the states in implementing the National Family Caregiver Support Program: a 50-state study.
- Author
-
Feinberg LF and Newman SL
- Abstract
Despite increased attention to policy choices to support family and informal caregivers, relatively little is known about states' experiences in providing caregiver support services. This article reports on the first nationwide survey of all 50 states and the District of Columbia in providing caregiver services since the passage of the National Family Caregiver Support Program. State program administrators reported that their program differs from other home and community-based services because of the explicit focus on the family or informal caregiver. Results suggest that despite an increasing availability of caregiver supports in all 50 states, there is also a great unevenness in services and service options for family caregivers across the states and within states. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
7. Characterization of patients with an increased susceptibility to bacterial infections and a genetic deficiency of leukocyte membrane complement receptor type 3 and the related membrane antigen LFA-1
- Author
-
Ross, GD, Thompson, RA, Walport, MJ, Springer, TA, Watson, JV, Ward, RH, Lida, J, Newman, SL, Harrison, RA, and Lachmann, PJ
- Abstract
Three children from two unrelated families had a history of recurrent bacterial infections, and their neutrophils were shown to have deficient phagocytic and respiratory responses and possible deficiencies in chemotaxis or adherence. Their neutrophils were strikingly deficient in the ability to ingest or give a respiratory burst in response to unopsonized bakers' yeast or zymosan (Z). Tests for neutrophil and monocyte CR1 (C3b/iC3b receptor) and CR3 (iC3b receptor) demonstrated rosettes with both EC3b and EC3bi. However, EC3bi were bound only to CR1, and not to CR3, because EC3bi rosettes were inhibited completely by anti-CR1. Neutrophils, monocytes, and natural killer (NK) cells also did not fluorescence stain with monoclonal antibodies specific for the alpha-chain of CR3 (anti-Mac-1, anti-Mol, OKM1, and MN-41). Quantitation of C receptors with 125I monoclonal anti-CR1 and anti-CR3 indicated that neutrophils from each patient expressed normal amounts of CR1 per cell but less than 10% of the normal amount of CR3. Examination of neutrophils by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that a normal glycoprotein of approximately 165,000 daltons was missing. Immunoblotting of these gels indicated that the missing band was the alpha-chain of CR3. Subsequent analysis of all three patients' cells also demonstrated a deficiency of LFA-1 alpha-chain and the common beta- chain that is shared by the CR3/LFA-1/p150,95 membrane antigen family. The deficiency of LFA-1 probably explained the absent NK cell function, as normal NK cell activity is inhibited by anti-LFA-1 but not by anti- CR3. The reduced phagocytic and respiratory responses to Z were probably due to CR3 deficiency, because treatment of normal neutrophils with anti-CR3, but not anti-FLA-1, inhibits responses to Z by 80% to 90%. Ingestion of Staphylococcus epidermidis by normal neutrophils was shown to be partially inhibited by monoclonal antibodies to the alpha- chain of either CR3 or LFA-1, and monoclonal antibody to the common beta-chain inhibited ingestion by 75%. Thus, both CR3 and LFA-1 may have previously unrecognized functions as phagocyte receptors for bacteria. The absence of this type of nonimmune recognition of bacteria by these children's neutrophils may be one of the reasons for their increased susceptibility to bacterial infections.
- Published
- 1985
- Full Text
- View/download PDF
8. Inhibition of zymosan activation of human neutrophil oxidative metabolism by a mouse monoclonal antibody
- Author
-
Nauseef, WM, Root, RK, Newman, SL, and Malech, HL
- Abstract
We have studied a neutrophil-specific murine monoclonal antibody, PMN7C3 (IgG3), which specifically alters PMN oxidative metabolism stimulated by serum-opsonized zymosan (STZ) or Candida albicans (STC). Polymorphonuclear cells (PMNs) exposed to PMN7C3 show a significant depression in O2- release (52.8% +/- 2.5% of control), H2O2 release (44.4% +/- 6.0% of control), and O2 consumption (73.9% +/- 2.6% of control) in response to STZ. O2 release in response to phorbol myristate acetate (PMA) was modestly reduced (78.4% +/- 3.7%) by PMN7C3 treatment, but not to the extent seen with STZ or STC. PMN7C3 did not affect O2 release by PMNs stimulated by zymosan opsonized with IgG or by S. aureus, A 23187, or FMLP. PMN7C3 was not cytotoxic, did not trigger oxidative metabolism when used as a stimulus, did not alter STZ- induced degranulation, and did not interfere with binding or uptake of STZ by PMNs. Exposure of PMNs to PMN7C3 decreased PMN rosette formation with erythrocytes coated with C3b (54% of control) or C3bi (63% of control), but had no affect on rosette formation with IgG-coated erythrocytes. PMN7C3 does not bind to monocytes and had no affect on rosette formation by this cell type. Binding of antibody PMN7C3 to the neutrophil surface inhibits the oxidative response to opsonized STZ or STC, possibly in part by altering the function or expression of C3b and C3bi receptors. Monoclonal antibodies such as PMN7C3 provide highly specific probes that may be used to define the molecular features of the stimulus-coupled response of PMN activation.
- Published
- 1983
- Full Text
- View/download PDF
9. Generation of three different fragments of bound C3 with purified factor I or serum. II. Location of binding sites in the C3 Fragments for Factors B and H, complement receptors , and bovine conglutinin
- Author
-
Ross, GD, Newman, SL, Lambris, JD, Devery-Pocius, JE, Cain, JA, and Lackmann, PJ
- Abstract
The many different recognized functions of C3 are dependent upon the ability of the activated C3 molecule both to bind covalently to protein and carbohydrate surfaces and to provide binding sites for as many as eleven different proteins. The location of the binding sites for six of these different proteins (factors B and H, complement receptors CR(1), CR(2) and CR(3) and conglutinin) was examined in the naturally occurring C3-fragments generated by C3 activation (C3b) and degradation by Factor I (iC3b, C3c, C3d,g) and trypsin (C3d). Evidence was obtained for at least four distinct binding sites in C3 for these six different C3 ligands. One binding site for B was detectable only in C3b, whereas a second binding site for H and CR(1) was detectable in both C3b and iC3b. The affinity of the binding site for H and CR(1) was charge dependent and considerably reduced in iC3b as compared to C3b. H binding to iC3b-coated sheep erythrocytes (EC3bi) was measurable only in low ionic strength buffer (4 mS). The finding that C3c-coated microspheres bound to CR(1), indicated that this second binding site was still intact in the C3c fragment. However, H binding to C3c was not examined. A third binding site in C3 for CR(2) was exposed in the d region by factor I cleavage of C3b into iC3b, and the activity of this site was unaffected by the further I cleavage of iC3b into C3d,g. Removal of the 8,000-dalton C3g fragment from C3d,g with trypsin forming C3d, resulted in reduced CR2 activity. However, because saturating amounts of monoclonal anti-C3g did not block the CR(2)-binding activity of EC3d,g, it appears unlikely that the g region of C3d,g or iC3b forms a part of the CR(2)-binding site. In addition, detergent-solubilized EC3d (C3d-OR) inhibited the CR(2)-binding activity of EC3d,g. Monocytes and neutrophils, that had been previously thought to lack CR(2) because of their inability to form EC3d rosettes, did bind EC3d,g containing greater than 5 × 10(4) C3d,g molecules per E. The finding that monocyte and neutrophil rosettes with EC3d,g were inhibited by C3d-OR, suggested that these phagocytic cells might indeed express very low numbers of CR(2), and that these CR(2) were detectable with EC3d,g and not with EC3d because C3d,g had a higher affinity for CR2 than did C3d. A fourth C3 binding site for CR(3) and conglutinin (K) was restricted to the iC3b fragment. Because of simultaneous attachment of iC3b to phagocyte CR3 and CR(3), the characteristics of iC3b binding to CR3 could only be examined with phagocytes on which the CR(1) had been blocked with anti-CR(1). Inhibition studies with EDTA and N-acetyl-D-glucosamine demonstrated a requirement for both calcium cations and carbohydrate in the binding of EC3bi to CR3 and to K. However, CR(3) differed from K in that magnesium cations were required in addition to calcium for maximum CR(3) binding activity, and NADG produced less inhibition of CR(3) activity than of K activity.
- Published
- 1983
- Full Text
- View/download PDF
10. Reye's syndrome: success of supportive care
- Author
-
Newman Sl, Ahmann Pa, and Caplan Db
- Subjects
Pediatrics ,medicine.medical_specialty ,business.industry ,Reye Syndrome ,medicine ,Methods ,Reye's syndrome ,Humans ,General Medicine ,medicine.disease ,business ,Child - Published
- 1978
11. Resolution of the clinical features of tyrosinemia following orthotopic liver transplantation for hepatoma
- Author
-
Van Thiel, DH, Gartner, LM, Thorp, FK, Newman, SL, Lindahl, JA, Stoner, E, New, MI, Starzl, TE, Van Thiel, DH, Gartner, LM, Thorp, FK, Newman, SL, Lindahl, JA, Stoner, E, New, MI, and Starzl, TE
- Abstract
The clinical history before transplantation and subsequent clinical and biochemical course of 3 children and one adult with hereditary tyrosinemia treated by orthotopic hepatic transplantation is described. All four patients are now free of their previous dietary restrictions and appear to be cured of both their metabolic disease and their hepatic neoplasm. © 1986 Elsevier Science Publishers B.V. All rights reserved.
- Published
- 1986
12. Monitoring Serum Osmolality in Mannitol Treatment of Reye's Syndrome
- Author
-
Newman Sl
- Subjects
medicine.medical_specialty ,business.industry ,Reye Syndrome ,Osmolar Concentration ,General Medicine ,medicine.disease ,Endocrinology ,Internal medicine ,medicine ,Humans ,Serum osmolality ,Reye's syndrome ,Mannitol ,business ,medicine.drug - Published
- 1979
- Full Text
- View/download PDF
13. Pediatric mandibular malignancies: a comprehensive analysis of SEER data.
- Author
-
Newman SL, Drury NB, Lee KT, Devarakonda AK, Ahmed A, and Koehn HK
- Subjects
- Humans, Male, Female, Child, Adolescent, Child, Preschool, Infant, United States epidemiology, Neoplasm Staging, Survival Rate, Infant, Newborn, Survival Analysis, SEER Program, Mandibular Neoplasms epidemiology, Mandibular Neoplasms pathology, Mandibular Neoplasms mortality
- Abstract
Mandibular malignancies are rare in the pediatric population and subsequently not well characterized. SEER 18 registry data was collected, applying age 0-18 years and ICD-O-3 code C41.1 ('mandible'). Univariate Cox regression analysis was conducted, and hazard ratios (HR) were calculated for overall survival (OS) and disease-specific survival (DSS) according to patient demographics, tumor characteristics, and treatment. Kaplan-Meier survival curves were generated for OS and DSS. Sixty-four patients met the inclusion criteria. The median age at diagnosis was 13.0 years, and median survival was 8.7 years. Osteosarcoma was the most common histological diagnosis (n = 22). Sex, race, age (<13 vs ≥13 years), histological type, odontogenic origin, and treatment modality were found not to be associated with OS or DSS. The SEER stage 'distant' was significantly associated with an elevated HR of 6.28 for DSS (P = 0.027) and 5.29 for OS (P = 0.025). Kaplan-Meier survival curves demonstrated significantly lower 5-year DSS (P<0.001) and OS (P<0.001) for SEER 'distant' stage. This study includes the analysis of a large number of pediatric mandibular malignancies when compared to previous studies. 'Distant' stage was associated with decreased survival. Early clinical suspicion and diagnosis are paramount for improved survival., Competing Interests: Competing interests None., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2025
- Full Text
- View/download PDF
14. Ruptured Intracranial Aneurysm Presenting as Isolated Acute Subdural Hemorrhage.
- Author
-
Babici D, Johansen PM, Newman SL, Packer E, and Snelling B
- Abstract
Ruptured intracranial aneurysms are often associated with serious neurologic sequelae, often as a result of subarachnoid or intraparenchymal hemorrhage. Less commonly, ruptured intracranial aneurysms can lead to subdural hemorrhage. However, the characteristic clinical presentation and optimal treatment of associated subdural hemorrhage are unclear due to the paucity of such cases that exist in the current literature. Affected patients may complain of nonspecific symptoms such as headaches, nausea, and confusion. Because of the severity of the disease, rapid diagnosis and intervention is required to lower the high morbidity and mortality rates. Commonly used treatment options include endovascular coiling and microsurgical clipping. Neuroendovascular surgery is often preferred, especially in aneurysms not amenable to surgical clipping, in poor surgical candidates, and cases with endovascularly favorable anatomy. The authors present the case of a patient who came to the hospital with ischemic stroke-like symptoms and was found to have a ruptured posterior communicating artery (PCoA) aneurysm and associated acute subdural hematoma (SDH) without obvious subarachnoid hemorrhage (SAH). Endovascular coiling of the aneurysm was performed successfully the following craniotomy for SDH evacuation, and the patient was discharged to a rehabilitation facility., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Babici et al.)
- Published
- 2022
- Full Text
- View/download PDF
15. Microdiscectomy Under Local Anesthesia and Spinal Block in a Pregnant Female.
- Author
-
Babici D, Johansen PM, Newman SL, O'Connor TE, and Miller TD
- Abstract
The surgical plan and the anesthetic approach are vital in determining the proper treatment of lumbar disc herniation in pregnancy. The diagnostic tools available, as well as the anesthetic agents and methods of delivery, vary in pregnant patients due to factors such as radiation exposure and hemodynamics in the patient and fetus. The gestational age also plays an important role in determining treatment options. When possible, surgery should be avoided during the first trimester, especially during the period of organogenesis, as general anesthesia can interfere with this process. However, when focal neurological deficits are present, urgent surgical decompression may be necessary. In such cases, the selection of anesthesia must be guided by maternal indications and the nature of the surgery. Maternal safety and avoidance of fetal hypoxia and subsequent preterm labor are crucial when pregnant patients receive anesthesia. As a result, local anesthesia is often preferred when possible due to the decreased risk of systemic toxicity. Decompression surgery in pregnant females with lumbar disc herniation, using a multidisciplinary approach among the surgeon, obstetrician, and anesthesiologist, is an effective and safe procedure for both the mother and the fetus. We present the case of a pregnant female at four weeks of gestation who presented with lower back pain radiating down her right leg. MRI of the lumbar spine showed large L4-5 disc herniation. She underwent a successful right L4-5 microdiscectomy under local anesthesia and spinal block using bupivacaine and was completely awake throughout the procedure. Postoperatively, she experienced immediate improvement of symptoms., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Babici et al.)
- Published
- 2021
- Full Text
- View/download PDF
16. Robotic-assisted pulley technique for the ventral hernia.
- Author
-
Butz JJ and Newman SL
- Subjects
- Humans, Surgical Mesh, Abdominal Wall surgery, Hernia, Ventral surgery, Laparoscopy, Robotic Surgical Procedures methods
- Abstract
When approaching complex abdominal wall hernias at either index operation or a subsequent reoperation for recurrent incarcerated abdominal wall hernias, a majority of surgeons consider mesh placement a key step in the prevention of a future recurrence. While the laparoscopic and open approaches show no significant difference in hernia recurrence, the laparoscopic approach to complex abdominal wall hernias does reduce surgical-site infection, postoperative ileus, improves short-term quality-of-life scores, and reduces hospital length of stay (Davies et al. in Am Surg 78(8):888-892, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3500604/ , 2012, McGreevy et al. in Surg Endosc 17(11):1778-1780, https://www.ncbi.nlm.nih.gov/pubmed/12958679 , 2003, Bittner et al. in Surg Endosc 33:3069-3139, https://doi.org/10.1007/s00464-019-06907-7 , 2019). In this paper, we describe a robotic approach with a pulley technique to the fixation of polypropylene mesh in complex abdominal wall reconstruction. Our primary aim is to offer a new perspective to the re-creation of challenging abdominal walls and to encourage other surgeons to gain proficiency in the robotic approach. Additionally, the material cost to the technique is lower than that of self-expanding or deployable mesh reinforcements used in other laparoscopic approaches. Over time, as an institution breaks even on the cost of a robot with their return on investment, this technique offers potential cost-saving., (© 2020. Springer-Verlag London Ltd., part of Springer Nature.)
- Published
- 2021
- Full Text
- View/download PDF
17. Should a Good Risk Manager Worry About Cost and Price Transparency in Health Care?
- Author
-
Hyatt JC and Newman SL
- Subjects
- Humans, Delivery of Health Care, Health Facilities
- Abstract
Roles of hospital risk managers have grown over the last 30 years. Once largely focused on hospital liability risk management, risk managers today have a broader set of enterprise risk management responsibilities. The following commentary about a surprise billing case considers roles of risk managers in promoting cost and price transparency., (© 2020 American Medical Association. All Rights Reserved.)
- Published
- 2020
- Full Text
- View/download PDF
18. North and south: A comprehensive analysis of non-adult growth and health in the industrial revolution (AD 18th-19th C), England.
- Author
-
Newman SL, Gowland RL, and Caffell AC
- Subjects
- Adolescent, Child, Child, Preschool, Dental Enamel Hypoplasia, England ethnology, Femur anatomy & histology, History, 18th Century, History, 19th Century, Humans, Industry history, Infant, Paleopathology, Spine anatomy & histology, Stress, Physiological, Tooth anatomy & histology, Vitamin D Deficiency, Body Height ethnology, Child Development physiology, Child Health ethnology, Child Health history
- Abstract
Objective: Stark health inequalities exist in the present day between the North and South of England, with people in the South, overall, experiencing better health across a range of parameters (e.g., life expectancy and number of years spent in good health). Bioarchaeological studies of skeletal remains from cemeteries across this geographical divide have the ability to provide a temporal perspective on the etiology, longevity, and nature of this disparity., Methods: In total 574 non-adults (0-17 years) from six urban sites (c. AD 1711-1856) were analyzed from the North and South of England. Measurements of long bone length, cortical thickness, and vertebral dimensions were analyzed alongside both skeletal and dental palaeopathological data to assess patterns of disease and growth disruption between skeletal samples., Results: There were few significant differences in growth parameters between the six sites in relation to geographical location. However, the northern-based sample Coach Lane (North Shields) demonstrated some of the highest rates of pathology, with metabolic disease being particularly prevalent., Discussion: Northern and southern populations suffered alike from the detrimental environmental conditions associated with urban centers of the 18th-19th centuries. However, the elevated prevalence of vitamin D deficiency seen within the Coach Lane sample is indicative of a regionally specific risk that may be related to latitude, and/or the influence of particular industries operating in the North-East., (© 2019 Wiley Periodicals, Inc.)
- Published
- 2019
- Full Text
- View/download PDF
19. Decreasing Unplanned Office Visits Due to Cast Problems in the Pediatric Population.
- Author
-
Newman SL and Gaffney JT
- Abstract
Introduction: Unplanned office visits due to cast-related problems in the pediatric orthopedic office are common. Decreasing problems associated with the use of a cast would improve patient safety, increase office productivity, and decrease inconvenience to the child and family., Methods: Pediatric patients treated with a cast in our office were included in the study if they returned for an unplanned office visit due to a cast-related problem. Group 1 received verbal cast care instruction. Group 2 had the same verbal instruction in addition to a written handout identical to the verbal instructions. Group 3 was provided the same verbal instructions and a revised handout limiting the number of instructions and focused on keeping the cast away from water., Results: The study included 550 patients with 146 in group 1, 124 in group 2, and 280 in group 3. Comparing group 1 (10.3%) and group 2 (10.5%), there was almost no difference in the rate of unplanned office visits due to cast-related problems. Combining the revised handout with verbal instructions in group 3, the percentage of patients returning for an unplanned visit was 6%. There was a relative decrease in office visits by 55% and an absolute decrease of 4.5% when comparing group 2 and group 3., Conclusions: There was a decrease in the number of unplanned office visits due to cast problems utilizing a handout focused on keeping the cast dry in collaboration with verbal cast care instructions. However, the decrease was not statistically significant.
- Published
- 2018
- Full Text
- View/download PDF
20. The curli regulator CsgD mediates stationary phase counter-silencing of csgBA in Salmonella Typhimurium.
- Author
-
Newman SL, Will WR, Libby SJ, and Fang FC
- Subjects
- Bacterial Proteins genetics, DNA-Binding Proteins genetics, DNA-Directed RNA Polymerases genetics, DNA-Directed RNA Polymerases metabolism, Fimbriae, Bacterial metabolism, Gene Expression Regulation, Bacterial, Operon, Promoter Regions, Genetic, Salmonella typhimurium physiology, Sigma Factor genetics, Trans-Activators genetics, Transcription, Genetic, Virulence, Bacterial Proteins metabolism, DNA-Binding Proteins metabolism, Gene Silencing, Salmonella typhimurium genetics, Sigma Factor metabolism, Trans-Activators metabolism
- Abstract
Integration of horizontally acquired genes into transcriptional networks is essential for the regulated expression of virulence in bacterial pathogens. In Salmonella enterica, expression of such genes is repressed by the nucleoid-associated protein H-NS, which recognizes and binds to AT-rich DNA. H-NS-mediated silencing must be countered by other DNA-binding proteins to allow expression under appropriate conditions. Some genes that can be transcribed by RNA polymerase (RNAP) associated with the alternative sigma factor σ
S or the housekeeping sigma factor σ70 in vitro appear to be preferentially transcribed by σS in the presence of H-NS, suggesting that σS may act as a counter-silencer. To determine whether σS directly counters H-NS-mediated silencing and whether co-regulation by H-NS accounts for the σS selectivity of certain promoters, we examined the csgBA operon, which is required for curli fimbriae expression and is known to be regulated by both H-NS and σS . Using genetics and in vitro biochemical analyses, we found that σS is not directly required for csgBA transcription, but rather up-regulates csgBA via an indirect upstream mechanism. Instead, the biofilm master regulator CsgD directly counter-silences the csgBA promoter by altering the DNA-protein complex structure to disrupt H-NS-mediated silencing in addition to directing the binding of RNAP., (© 2018 John Wiley & Sons Ltd.)- Published
- 2018
- Full Text
- View/download PDF
21. Dedicated Followers of Fashion? Bioarchaeological Perspectives on Socio-Economic Status, Inequality, and Health in Urban Children from the Industrial Revolution (18th-19th C), England.
- Author
-
Newman SL and Gowland RL
- Abstract
The 18th and 19th centuries in England were characterised by a period of increasing industrialisation of its urban centres. It was also one of widening social and health inequalities between the rich and the poor. Childhood is well-documented as being a stage in the life course during which the body is particularly sensitive to adverse socio-economic environments. This study therefore aims to examine the relationship between health and wealth through a comprehensive skeletal analysis of a sample of 403 children (0-17 years), of varying socio-economic status, from four cemetery sites in London (c.1712-1854). Measurements of long bone diaphyseal length, cortical thickness, vertebral neural canal size, and the prevalence of a range of pathological indicators of health stress were recorded from the Chelsea Old Church (high status), St Benet Sherehog (middle status), Bow Baptist (middle status), and Cross Bones (low status) skeletal collections. Children from the low status Cross Bones site demonstrated deficient growth values, as expected. However, those from the high status site of Chelsea Old Church also demonstrated poor growth values during infancy. Fashionable child-care practices (e.g. the use of artificial infant feeds and keeping children indoors) may have contributed to poor infant health amongst high status groups. However, differing health risks in the lower status group revealed the existence of substantial health inequality in London at this time., (© 2016 The Authors International Journal of Osteoarchaeology Published by John Wiley & Sons Ltd.)
- Published
- 2017
- Full Text
- View/download PDF
22. Family Meal Frequency and Association with Household Food Availability in United States Multi-Person Households: National Health and Nutrition Examination Survey 2007-2010.
- Author
-
Newman SL, Tumin R, Andridge R, and Anderson SE
- Subjects
- Adolescent, Adult, Female, Humans, Male, Socioeconomic Factors, United States, Family, Family Characteristics, Food Supply, Nutrition Surveys
- Abstract
Objective: Family meals are associated with a healthier diet among children and adolescents, but how family meal frequency varies in the U.S. population overall by household food availability and sociodemographic characteristics is not well characterized., Design: The U.S. National Health and Nutrition Examination Survey 2007-2010 assessed the frequency of family meals eaten at home in the past week and the household availability of fruits, dark green vegetables, salty snacks, and sugar-sweetened beverages., Setting: Computer-assisted face-to-face interviews with a selected adult (≥18 years) who owned or rented the home (i.e., the household reference person)., Subjects: We analyzed information on family meal frequency for 18,031 participants living in multi-person households in relation to sociodemographic characteristics and food availability., Results: Among the U.S. population living in households of two or more individuals, the prevalence (95% confidence interval) of having 0-2, 3-6 and ≥7 family meals/week was 18.0% (16.6-19.3), 32.4% (31.0-33.9), and 49.6% (47.8-51.4), respectively. Greater household availability of fruits and dark green vegetables and less availability of salty snacks and sugar-sweetened beverages was associated with more frequent family meals. Family meals were more prevalent in low-income households and those in which the reference person was ≥65 years, married, or had less than high school education., Conclusions: About half of the US population living in households of 2 or more people shares meals frequently with their family at home. Family meal frequency was positively associated with a healthier pattern of household food availability.
- Published
- 2015
- Full Text
- View/download PDF
23. The use of non-adult vertebral dimensions as indicators of growth disruption and non-specific health stress in skeletal populations.
- Author
-
Newman SL and Gowland RL
- Subjects
- Adolescent, Anthropology, Physical, Child, Child, Preschool, Humans, Infant, Infant, Newborn, London, Body Height physiology, Spine anatomy & histology, Spine growth & development, Stress, Physiological physiology
- Abstract
Objective: Traditional methods of detecting growth disruption have focused on deficiencies in the diaphyseal length of the long bones. This study proposes the implementation of vertebral measurements (body height and transverse diameter of the neural canal) from non-adults (0-17 years) as a new methodology for the identification of growth disruption., Methods: Measurements of vertebral body height and transverse diameter were taken from 96 non-adult skeletons and 40 adult skeletons from two post-medieval sites in England (Bow Baptist, London and Coronation Street, South Shields). Non-adult measurements were plotted against dental age to construct vertebral growth profiles through which inter-population comparisons could be made., Results: Results demonstrated that both sites experienced some growth retardation in infancy, evident as deficiencies in transverse diameter. However, analysis of vertebral body height revealed different chronologies of growth disruption between the sites, with a later age of attainment of skeletal maturity recorded in the Bow Baptist sample., Discussion: These vertebral dimensions undergo cessation of growth at different ages, with transverse diameter being "locked-in" by ∼1-2 years of age, while vertebral body height may continue to grow into early adulthood. These measurements can therefore provide complementary information regarding the timing of growth disruption within archaeological populations. Non-adult vertebral measurements can increase our osteobiographical understanding of the timings of episodes of health stress, and allow for the analysis of growth when other skeletal elements are fragmentary., (© 2015 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.)
- Published
- 2015
- Full Text
- View/download PDF
24. Recruitment for longitudinal, randomised pregnancy trials initiated preconception: lessons from the effects of aspirin in gestation and reproduction trial.
- Author
-
Lesher LL, Matyas RA, Sjaarda LA, Newman SL, Silver RM, Galai N, Hovey KM, Wactawski-Wende J, Emerick L, Lynch AM, Mead B, Townsend JM, Perkins NJ, Mumford SL, Stanford J, and Schisterman EF
- Subjects
- Adult, Cost-Benefit Analysis, Double-Blind Method, Female, Humans, Infant, Newborn, Live Birth, Preconception Care, Pregnancy, Research Design, United States epidemiology, Anti-Inflammatory Agents, Non-Steroidal administration & dosage, Aspirin administration & dosage, Patient Selection, Pregnancy Outcome epidemiology
- Abstract
Background: Recruitment into large, preconception randomised clinical trials (RCT) is challenging. We describe clinic and community-based preconception recruitment strategies for the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial and highlight approaches that were and were not successful. This longitudinal RCT was conducted at four major sites in the US. Eligible women had one to two prior pregnancy losses and were actively trying to become pregnant., Methods: Provider/clinic and community-based outreach strategies were utilised, and the recruitment rate and costs of methods were assessed., Results: A screening questionnaire was completed by 5485 women; 42.4% (n = 2323) screened were initially eligible, of whom 50.7% (n = 1228) were randomised. Provider/clinic-based recruitment yielded the highest number eligible of those screened (30.1%) and also the most randomised participants overall (40.3%). The next highest yield came from direct mail and brochures/flyers at 13.1% and 12.5% of women randomised, respectively. However, direct mailings cost $720 per participant randomised. Other than word of mouth, provider/clinic-based recruitment was the most cost effective method, costing an average of $60 per randomised participant. Web-based recruitment yielded 4.7% of participants at a cost of $278 per randomised participant., Conclusions: Provider and clinic-based recruitment was the most effective and cost-efficient method of recruitment in a preconception intervention study of reproduction among women., (© 2015 John Wiley & Sons Ltd.)
- Published
- 2015
- Full Text
- View/download PDF
25. Iron uptake and virulence in Histoplasma capsulatum.
- Author
-
Newman SL and Smulian AG
- Subjects
- Virulence, Histoplasma metabolism, Histoplasma pathogenicity, Iron metabolism, Macrophages microbiology, Phagosomes microbiology
- Abstract
Histoplasma capsulatum (Hc) is the causative organism of a spectrum of disease affecting both the immunocompetent and the immunocompromised host. Hc is a dimporhic fungus that converts from conidia to the pathogenic yeast phase after entry into the mammalian host. Despite rapid ingestion by macrophages, it survives intracellularly within the macrophage. The intracellular survival strategy of Hc yeasts focuses on regulating the phagosomal compartment by modulating the intraphagosomal pH to 6.5. As an intracellular pathogen of MΦ, Hc obtains iron from Fe-transferrin, ferritin, or both, via the production of hydroxamate siderophores, and the production of ferric reductases. A better understanding of the mechanisms by which Hc yeasts acquire iron from the host may lead to novel therapeutics for histoplasmosis., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
26. HacA-independent functions of the ER stress sensor IreA synergize with the canonical UPR to influence virulence traits in Aspergillus fumigatus.
- Author
-
Feng X, Krishnan K, Richie DL, Aimanianda V, Hartl L, Grahl N, Powers-Fletcher MV, Zhang M, Fuller KK, Nierman WC, Lu LJ, Latgé JP, Woollett L, Newman SL, Cramer RA Jr, Rhodes JC, and Askew DS
- Subjects
- Animals, Animals, Outbred Strains, Aspergillus fumigatus genetics, Aspergillus fumigatus metabolism, Disease Models, Animal, Endoplasmic Reticulum genetics, Female, Fungal Proteins genetics, Fungal Proteins metabolism, Gene Expression Profiling, Gene Expression Regulation, Genes, Fungal, Humans, Iron-Regulatory Proteins genetics, Lung microbiology, Lung pathology, Membrane Glycoproteins, Mice, Mutation, RNA, Messenger metabolism, Repressor Proteins genetics, Virulence genetics, Aspergillus fumigatus pathogenicity, Endoplasmic Reticulum metabolism, Iron-Regulatory Proteins metabolism, Repressor Proteins metabolism, Unfolded Protein Response physiology
- Abstract
Endoplasmic reticulum (ER) stress is a condition in which the protein folding capacity of the ER becomes overwhelmed by an increased demand for secretion or by exposure to compounds that disrupt ER homeostasis. In yeast and other fungi, the accumulation of unfolded proteins is detected by the ER-transmembrane sensor IreA/Ire1, which responds by cleaving an intron from the downstream cytoplasmic mRNA HacA/Hac1, allowing for the translation of a transcription factor that coordinates a series of adaptive responses that are collectively known as the unfolded protein response (UPR). Here, we examined the contribution of IreA to growth and virulence in the human fungal pathogen Aspergillus fumigatus. Gene expression profiling revealed that A. fumigatus IreA signals predominantly through the canonical IreA-HacA pathway under conditions of severe ER stress. However, in the absence of ER stress IreA controls dual signaling circuits that are both HacA-dependent and HacA-independent. We found that a ΔireA mutant was avirulent in a mouse model of invasive aspergillosis, which contrasts the partial virulence of a ΔhacA mutant, suggesting that IreA contributes to pathogenesis independently of HacA. In support of this conclusion, we found that the ΔireA mutant had more severe defects in the expression of multiple virulence-related traits relative to ΔhacA, including reduced thermotolerance, decreased nutritional versatility, impaired growth under hypoxia, altered cell wall and membrane composition, and increased susceptibility to azole antifungals. In addition, full or partial virulence could be restored to the ΔireA mutant by complementation with either the induced form of the hacA mRNA, hacA(i), or an ireA deletion mutant that was incapable of processing the hacA mRNA, ireA(Δ10). Together, these findings demonstrate that IreA has both HacA-dependent and HacA-independent functions that contribute to the expression of traits that are essential for virulence in A. fumigatus.
- Published
- 2011
- Full Text
- View/download PDF
27. Histoplasma capsulatum utilizes siderophores for intracellular iron acquisition in macrophages.
- Author
-
Hilty J, George Smulian A, and Newman SL
- Subjects
- Animals, Cells, Cultured, Colony Count, Microbial, Disease Models, Animal, Gene Knockdown Techniques, Gene Knockout Techniques, Histoplasmosis microbiology, Histoplasmosis pathology, Humans, Lung microbiology, Lung Diseases microbiology, Lung Diseases pathology, Male, Mice, Mice, Inbred C57BL, Rodent Diseases microbiology, Rodent Diseases pathology, Siderophores genetics, Spleen microbiology, Survival Analysis, Histoplasma metabolism, Histoplasma pathogenicity, Iron metabolism, Macrophages microbiology, Siderophores metabolism
- Abstract
Histoplasma capsulatum is a dimorphic fungal pathogen that survives and replicates within macrophages (MΦ). Studies in human and murine MΦ demonstrate that the intracellular growth of H. capsulatum yeasts is exquisitely sensitive to the availability of iron. As H. capsulatum produces hydroxamate siderophores, we sought to determine if siderophores were required for intracellular survival in MΦ, and in a murine model of pulmonary histoplasmosis. The expression of SID1 (coding for L-ornithine-N(5)-monooxygenase) was silenced by RNA interference (RNAi) in H. capsulatum strain G217B, and abolished by gene targeting in strain G186AR. G217B SID1-silenced yeasts grew normally in rich medium, did not synthesize siderophores, and were unable to grow on apotransferrin-chelated medium. Their intracellular growth in human and murine MΦ was significantly decreased compared to wild type (WT) yeasts, but growth was restored to WT levels by the addition of exogenous iron, or restoration of SID1 expression. Similar results were obtained with G186AR Δsid1 yeasts. Compared to WT yeasts, G217B SID1-silenced yeasts demonstrated in C57BL/6 mice significantly reduced growth in the lungs and spleens seven days after infection, and 40% of the mice given a normally lethal inoculum of G217B SID1-silenced yeasts survived. These experiments demonstrate that: (1) SID1 expression is required for siderophore biosynthesis by H. capsulatum strain G217B, (2) SID1 expression is required for optimum intracellular growth in MΦ, and (3) inhibition of SID1 expression in vivo reduces the virulence of H. capsulatum yeasts., (© 2011 ISHAM)
- Published
- 2011
- Full Text
- View/download PDF
28. Dendritic cells restrict the transformation of Histoplasma capsulatum conidia into yeasts.
- Author
-
Newman SL, Lemen W, and Smulian AG
- Subjects
- Animals, Cells, Cultured, Green Fluorescent Proteins, Humans, Mice, Phagocytosis, Dendritic Cells microbiology, Histoplasma growth & development, Macrophages microbiology, Spores, Fungal growth & development
- Abstract
Infections due to Histoplasma capsulatum occur as a result of the inhalation of airborne microconidia of the mold into the alveoli of the lungs. In this study we quantified the transformation over time of conidia into yeast-like cells within macrophages (MΦ) and dendritic cells (DC). Conidia from strain G217B which had been surface labeled with carboxy-fluorescein succinimidyl ester (CFSE), or conidia from strain G217B that expresses green fluorescent protein (GFP) only in the yeast phase, were used to infect MΦ and DC. At various time points, numbers of intracellular conidia or yeasts were quantified via phase-contrast and fluorescent microscopy. Transformation of conidia from non-GFP-expressing G217B also was quantified by their incorporation of ³H-leucine. In both human and murine MΦ, numerous yeast-like cells appeared by day 3 post-infection. The time course of conidia transformation into yeasts in culture medium was the same as in MΦ. However, transformation of conidia to yeasts was significantly restricted in human DC and murine lung DC. In DC, significant numbers of yeasts did not appear until 5 days post-infection. Further, MΦ monolayers were destroyed by day 6-7 post-infection, whereas DC monolayers remained intact throughout the study period. These data suggest that in vivo, conidia may transform into yeast-like cells efficiently whether or not they are phagocytosed by MΦ, but not when ingested by DC.
- Published
- 2011
- Full Text
- View/download PDF
29. A case of a neuropathic diabetic foot ulcer causing rupture of the Achilles tendon.
- Author
-
Saleem HA, Newman SL, Puckridge PJ, and Spark JI
- Subjects
- Achilles Tendon physiopathology, Angioplasty methods, Diabetes Mellitus, Type 1 diagnosis, Diabetic Foot diagnosis, Diabetic Neuropathies diagnosis, Female, Femoral Artery surgery, Follow-Up Studies, Humans, Middle Aged, Peripheral Arterial Disease diagnostic imaging, Peripheral Arterial Disease surgery, Radiography, Rupture, Spontaneous etiology, Rupture, Spontaneous therapy, Splints, Stents, Tendon Injuries therapy, Treatment Outcome, Achilles Tendon pathology, Diabetes Mellitus, Type 1 complications, Diabetic Foot complications, Diabetic Neuropathies complications, Tendon Injuries etiology
- Published
- 2010
- Full Text
- View/download PDF
30. Histoplasma capsulatum cyclophilin A mediates attachment to dendritic cell VLA-5.
- Author
-
Gomez FJ, Pilcher-Roberts R, Alborzi A, and Newman SL
- Subjects
- Antigens, Fungal metabolism, Blotting, Western, Cyclophilin A genetics, Cyclophilin A metabolism, Dendritic Cells immunology, Flow Cytometry, Histoplasma genetics, Histoplasma metabolism, Humans, Integrin alpha5beta1 metabolism, Macrophages immunology, Macrophages microbiology, RNA Interference, Reverse Transcriptase Polymerase Chain Reaction, Antigens, Fungal immunology, Cyclophilin A immunology, Dendritic Cells microbiology, Histoplasma immunology, Integrin alpha5beta1 immunology
- Abstract
Histoplasma capsulatum (Hc) is a pathogenic fungus that replicates in macrophages (Mphi). In dendritic cells (DC), Hc is killed and fungal Ags are processed and presented to T cells. DC recognize Hc yeasts via the VLA-5 receptor, whereas Mphi recognize yeasts via CD18. To identify ligand(s) on Hc recognized by DC, VLA-5 was used to probe a Far Western blot of a yeast freeze/thaw extract (F/TE) that inhibited Hc binding to DC. VLA-5 recognized a 20-kDa protein, identified as cyclophilin A (CypA), and CypA was present on the surface of Hc yeasts. rCypA inhibited the attachment of Hc to DC, but not to Mphi. Silencing of Hc CypA by RNA interference reduced yeast binding to DC by 65-85%, but had no effect on binding to Mphi. However, F/TE from CypA-silenced yeasts still inhibited binding of wild-type Hc to DC, and F/TE from wild-type yeasts depleted of CypA also inhibited yeast binding to DC. rCypA did not further inhibit the binding of CypA-silenced yeasts to DC. Polystyrene beads coated with rCypA or fibronectin bound to DC and Mphi and to Chinese hamster ovary cells transfected with VLA-5. Binding of rCypA-coated beads, but not fibronectin-coated beads, was inhibited by rCypA. These data demonstrate that CypA serves as a ligand for DC VLA-5, that binding of CypA to VLA-5 is at a site different from FN, and that there is at least one other ligand on the surface of Hc yeasts that mediates binding of Hc to DC.
- Published
- 2008
- Full Text
- View/download PDF
31. The Histoplasma capsulatum vacuolar ATPase is required for iron homeostasis, intracellular replication in macrophages and virulence in a murine model of histoplasmosis.
- Author
-
Hilty J, Smulian AG, and Newman SL
- Subjects
- Agrobacterium tumefaciens genetics, Animals, DNA, Fungal genetics, Fungal Proteins genetics, Genes, Fungal, Genetic Complementation Test, Histoplasma enzymology, Histoplasma physiology, Homeostasis, Humans, Lung Diseases, Fungal microbiology, Male, Mice, Mice, Inbred C57BL, Mutagenesis, Insertional, Phenotype, Plasmids, Reverse Transcriptase Polymerase Chain Reaction, Siderophores metabolism, Transformation, Bacterial, Virulence genetics, Histoplasma genetics, Histoplasmosis microbiology, Iron metabolism, Macrophages microbiology, Vacuolar Proton-Translocating ATPases genetics
- Abstract
Histoplasma capsulatum is a dimorphic fungal pathogen that survives and replicates within macrophages (Mphi). To identify specific genes required for intracellular survival, we utilized Agrobacterium tumefaciens-mediated mutagenesis, and screened for H. capsulatum insertional mutants that were unable to survive in human Mphi. One colony was identified that had an insertion within VMA1, the catalytic subunit A of the vacuolar ATPase (V-ATPase). The vma1 mutant (vma1::HPH) grew normally on iron-replete medium, but not on iron-deficient media. On iron-deficient medium, the growth of the vma1 mutant was restored in the presence of wild-type (WT) H. capsulatum yeasts, or the hydroxamate siderophore, rhodotorulic acid. However, the inability to replicate within Mphi was only partially restored by the addition of exogenous iron. The vma1::HPH mutant also did not grow as a mold at 28 degrees C. Complementation of the mutant (vma/VMA1) restored its ability to replicate in Mphi, grow on iron-poor medium and grow as a mold at 28 degrees C. The vma1::HPH mutant was avirulent in a mouse model of histoplasmosis, whereas the vma1/VMA1 strain was as pathogenic as WT yeasts. These studies demonstrate the importance of V-ATPase function in the pathogenicity of H. capsulatum, in iron homeostasis and in fungal dimorphism.
- Published
- 2008
- Full Text
- View/download PDF
32. Acetazolamide 125 mg BD is not significantly different from 375 mg BD in the prevention of acute mountain sickness: the prophylactic acetazolamide dosage comparison for efficacy (PACE) trial.
- Author
-
Basnyat B, Gertsch JH, Holck PS, Johnson EW, Luks AM, Donham BP, Fleischman RJ, Gowder DW, Hawksworth JS, Jensen BT, Kleiman RJ, Loveridge AH, Lundeen EB, Newman SL, Noboa JA, Miegs DP, O'Beirne KA, Philpot KB, Schultz MN, Valente MC, Wiebers MR, and Swenson ER
- Subjects
- Adult, Altitude, Confidence Intervals, Dose-Response Relationship, Drug, Double-Blind Method, Female, Humans, Male, Nepal, Odds Ratio, Prospective Studies, Pulmonary Edema prevention & control, Treatment Outcome, Acetazolamide administration & dosage, Altitude Sickness drug therapy, Altitude Sickness prevention & control, Carbonic Anhydrase Inhibitors administration & dosage, Mountaineering
- Abstract
750 mg per day of acetazolamide in the prevention of acute mountain sickness (AMS), as recommended in the meta-analysis published in 2000 in the British Medical Journal, may be excessive and is controversial. To determine if the efficacy of low-dose acetazolamide 125 mg bd (250 mg), as currently used in the Himalayas, is significantly different from 375 mg bd (750 mg) of acetazolamide in the prevention of AMS, we designed a prospective, double-blind, randomized, placebo-controlled trial. The participants were sampled from a diverse population of (non-Nepali) trekkers at Namche Bazaar (3440 m) in Nepal on the Everest trekking route as they ascended to study midpoints (4280 m/4358 m) and the endpoint, Lobuje (4928 m), where data were collected. Participants were randomly assigned to receive 375 mg bd of acetazolamide (82 participants), 125 mg bd of acetazolamide (74 participants), or a placebo (66 participants), beginning at 3440 m for up to 6 days as they ascended to 4928 m. The results revealed that composite AMS incidence for 125 mg bd was similar to the incidence for 375 mg bd (24% vs. 21%, 95% confidence interval, -12.6%, 19.8%), in contrast to significantly greater AMS (51%) observed in the placebo group (95% confidence interval for differences: 8%, 46%; 12%, 49% for low and high comparisons, respectively). Both doses of acetazolamide improved oxygenation equally (82.9% for 250 mg daily and 82.8% for 750 mg daily), while placebo endpoint oxygen saturation was significantly less at 80.7% (95% confidence interval for differences: 0.5%, 3.9% and 0.4%, 3.7% for low and high comparisons, respectively). There was also more paresthesia in the 375-mg bd group (p < 0.02). We conclude that 125 mg bd of acetazolamide is not significantly different from 375 mg bd in the prevention of AMS; 125 mg bd should be considered the preferred dosage when indicated for persons ascending to altitudes above 2500 m.
- Published
- 2006
- Full Text
- View/download PDF
33. Human macrophages do not require phagosome acidification to mediate fungistatic/fungicidal activity against Histoplasma capsulatum.
- Author
-
Newman SL, Gootee L, Hilty J, and Morris RE
- Subjects
- Animals, Antifungal Agents pharmacology, Cells, Cultured, Histoplasma ultrastructure, Humans, Hydrogen-Ion Concentration, Interferon-gamma physiology, Macrolides pharmacology, Macrophages metabolism, Macrophages ultrastructure, Macrophages, Peritoneal drug effects, Macrophages, Peritoneal immunology, Mice, Microscopy, Immunoelectron, Phagosomes metabolism, Phagosomes ultrastructure, Zymosan metabolism, Histoplasma immunology, Macrophages immunology, Macrophages microbiology, Phagocytosis immunology, Phagosomes immunology, Phagosomes microbiology
- Abstract
Histoplasma capsulatum (Hc) is a facultative intracellular fungus that modulates the intraphagosomal environment to survive within macrophages (Mphi). In the present study, we sought to quantify the intraphagosomal pH under conditions in which Hc yeasts replicated or were killed. Human Mphi that had ingested both viable and heat-killed or fixed yeasts maintained an intraphagosomal pH of approximately 6.4-6.5 over a period of several hours. These results were obtained using a fluorescent ratio technique and by electron microscopy using the 3-(2,4-dinitroanilo)-3'-amino-N-methyldipropylamine reagent. Mphi that had ingested Saccharomyces cerevisae, a nonpathogenic yeast that is rapidly killed and degraded by Mphi, also maintained an intraphagosomal pH of approximately 6.5 over a period of several hours. Stimulation of human Mphi fungicidal activity by coculture with chloroquine or by adherence to type 1 collagen matrices was not reversed by bafilomycin, an inhibitor of the vacuolar ATPase. Human Mphi cultured in the presence of bafilomycin also completely degraded heat-killed Hc yeasts, whereas mouse peritoneal Mphi digestion of yeasts was completely reversed in the presence of bafilomycin. However, bafilomycin did not inhibit mouse Mphi fungistatic activity induced by IFN-gamma. Thus, human Mphi do not require phagosomal acidification to kill and degrade Hc yeasts, whereas mouse Mphi do require acidification for fungicidal but not fungistatic activity.
- Published
- 2006
- Full Text
- View/download PDF
34. Human dendritic cell activity against Histoplasma capsulatum is mediated via phagolysosomal fusion.
- Author
-
Gildea LA, Ciraolo GM, Morris RE, and Newman SL
- Subjects
- Catecholamines pharmacology, Dendritic Cells metabolism, Enzyme Inhibitors pharmacology, Histoplasma pathogenicity, Humans, Imidazolines pharmacology, Immunity, Cellular immunology, Nitric Oxide metabolism, Phagosomes drug effects, Phagosomes ultrastructure, Respiratory Burst drug effects, Suramin pharmacology, omega-N-Methylarginine pharmacology, Dendritic Cells immunology, Dendritic Cells microbiology, Histoplasma growth & development, Phagocytosis immunology, Phagosomes microbiology
- Abstract
Histoplasma capsulatum is a fungal pathogen that requires the induction of cell-mediated immunity (CMI) for host survival. We have demonstrated that human dendritic cells (DC) phagocytose H. capsulatum yeasts and, unlike human macrophages (Mø) that are permissive for intracellular growth, DC killed and degraded the fungus. In the present study, we sought to determine whether the mechanism(s) by which DC kill Histoplasma is via lysosomal hydrolases, via the production of toxic oxygen metabolites, or both. Phagosome-lysosome fusion (PL-fusion) was quantified by using fluorescein isothiocyanate-dextran and phase and fluorescence microscopy and by electron microscopy with horseradish peroxidase colloidal gold to label lysosomes. Unlike Mphi, Histoplasma-infected DC exhibited marked PL-fusion. The addition of suramin to Histoplasma-infected DC inhibited PL-fusion and DC fungicidal activity. Incubation of Histoplasma-infected DC at 18 degrees C also concomitantly reduced PL-fusion and decreased the capacity of DC to kill and degrade H. capsulatum yeasts. Further, culture of Histoplasma-infected DC in the presence of bafilomycin, an inhibitor of the vacuolar ATPase, did not block DC anti-Histoplasma activity, indicating that phagosome acidification was not required for lysosome enzyme activity. In contrast, culture of Histoplasma-infected DC in the presence of inhibitors of the respiratory burst or inhibitors of NO synthase had little to no effect on DC fungicidal activity. These data suggest that the major mechanism by which human DC mediate anti-Histoplasma activity is through the exposure of yeasts to DC lysosomal hydrolases. Thus, DC can override one of the strategies used by H. capsulatum yeasts to survive intracellularly within Mø.
- Published
- 2005
- Full Text
- View/download PDF
35. Enhanced killing of Candida albicans by human macrophages adherent to type 1 collagen matrices via induction of phagolysosomal fusion.
- Author
-
Newman SL, Bhugra B, Holly A, and Morris RE
- Subjects
- Cell Adhesion immunology, Fibronectins immunology, Humans, Laminin immunology, Time Factors, Vitronectin immunology, Candida albicans immunology, Candidiasis immunology, Collagen Type I immunology, Macrophages immunology, Phagosomes immunology
- Abstract
Candida albicans, a component of the normal flora of the alimentary tract and mucocutaneous membranes, is the leading cause of invasive fungal disease in premature infants, diabetics, and surgical patients and of oropharyngeal disease in AIDS patients. As little is known about the regulation of monocyte/macrophage anti-Candida activity, we sought to determine if fungicidal activity might be regulated by extracellular matrix proteins to which monocytes/macrophages are adherent in vivo. Compared to monocyte/macrophages that adhered to plastic, human monocytes and monocyte-derived macrophages that adhered to type 1 collagen matrices, but not to fibronectin, vitronectin, or laminin, demonstrated a significant increase in candidacidal activity. The enhancement of monocyte fungicidal activity was maintained over a 4-h period, whereas macrophage fungicidal activity was maximum at 1 h. Although adherence of monocytes and macrophages to collagen matrices concomitantly enhanced the production of superoxide anion, only the fungicidal activity of collagen-adherent monocytes was partially blocked by superoxide dismutase and catalase. Remarkably, we found that only 10% of the phagosomes in C. albicans-infected macrophages that adhered to plastic fused with lysosomes. In contrast, 80% of yeast-containing phagosomes of collagen-adherent macrophages fused with lysosomes. These data suggest that nonoxidative mechanisms are critical for human macrophage anti-Candida activity and that C. albicans pathogenicity is mediated, in part, by its ability to inhibit phagolysosomal fusion in macrophages.
- Published
- 2005
- Full Text
- View/download PDF
36. Interaction of Histoplasma capsulatum with human macrophages, dendritic cells, and neutrophils.
- Author
-
Newman SL
- Subjects
- Antigen Presentation, Dendritic Cells immunology, Histoplasma growth & development, Histoplasma immunology, Humans, Immunity, Cellular, Immunologic Techniques, In Vitro Techniques, Macrophages immunology, Mycology methods, Neutrophils immunology, Phagocytosis, Dendritic Cells microbiology, Histoplasma pathogenicity, Macrophages microbiology, Neutrophils microbiology
- Abstract
Histoplasma capsulatum (Hc) is a dimorphic fungal pathogen indigenous to the Ohio and Mississippi River Valleys in the United States. Infection is initiated by inhalation of microconidia or small mycelial fragments into the terminal bronchioles of the lung. The conidia are taken up by alveolar macrophages (Mphi), in which they convert to the pathogenic yeast phase. The yeasts replicate in the alveolar Mphi and other Mphi recruited to the lung as part of the inflammatory response. Thus, the yeasts are able to disseminate from the lung to other organs, such as the liver and spleen. As a facultative intracellular parasite, the interaction of Hc yeasts with Mphi is a critical component of the host response to infection. In addition, Hc yeasts have critical interactions with inflammatory neutrophils, and with dendritic cells (DCs) in the lung and other organs. Indeed, recent new evidence suggests that DCs may be the key antigen-presenting cells that initiate cell-mediated immunity. Thus, the methods described in this chapter cover quantitation of the binding, ingestion, and intracellular replication of Hc yeasts in human Mphi, DCs, and neutrophils.
- Published
- 2005
- Full Text
- View/download PDF
37. A study of 10 states since passage of the national family caregiver support program: policies, perceptions, and program development.
- Author
-
Feinberg LF and Newman SL
- Subjects
- Aged, Attitude to Health, Family, Health Policy, Humans, Long-Term Care economics, Organizational Case Studies, Program Development, United States, Caregivers economics, Financing, Government, Health Services for the Aged economics, Home Nursing economics, Social Support, Social Work economics, State Health Plans organization & administration
- Abstract
Purpose: This study describes the preliminary experiences of 10 states in providing support services to family or informal caregivers of elderly adults and adults with disabilities; it focuses on the newly created National Family Caregiver Support Program, state general funds, Medicaid-waiver programs, and other state-funding streams., Design and Methods: Case studies were conducted, between March and July 2002, through in-person interviews with state officials and stakeholders in Alabama, California, Florida, Hawaii, Indiana, Iowa, Maine, Pennsylvania, Texas, and Washington., Results: States were in the start-up phase of implementing the National Family Caregiver Support Program and varied greatly in program design and integration of caregiver support into their home- and community-based care system. Viewing family caregivers as a client population was a paradigm shift for many state officials., Implications: Heavy reliance is currently placed on family and informal caregivers in home- and community-based care, without adequate support services. Family support should be an explicit goal of long-term-care system reform.
- Published
- 2004
- Full Text
- View/download PDF
38. Identification of heat shock protein 60 as the ligand on Histoplasma capsulatum that mediates binding to CD18 receptors on human macrophages.
- Author
-
Long KH, Gomez FJ, Morris RE, and Newman SL
- Subjects
- Animals, Binding, Competitive immunology, CD11 Antigens metabolism, CHO Cells, Cell Adhesion immunology, Cells, Cultured, Chaperonin 60 analysis, Chaperonin 60 metabolism, Cricetinae, Dendritic Cells immunology, Dendritic Cells metabolism, Dendritic Cells microbiology, Fungal Proteins metabolism, Histoplasma immunology, Histoplasma metabolism, Humans, Macrophages immunology, Membrane Proteins analysis, Membrane Proteins biosynthesis, Membrane Proteins metabolism, Protein Binding immunology, CD18 Antigens metabolism, Chaperonin 60 physiology, Histoplasma physiology, Macrophage-1 Antigen metabolism, Macrophages metabolism, Macrophages microbiology
- Abstract
Histoplasma capsulatum (Hc), is a facultative intracellular fungus that binds to CD11/CD18 receptors on macrophages (Mphi). To identify the ligand(s) on Hc yeasts that is recognized by Mphi, purified human complement receptor type 3 (CR3, CD11b/CD18) was used to probe a Far Western blot of a detergent extract of Hc cell wall and cell membrane. CR3 recognized a single 60-kDa protein, which was identified as heat shock protein 60 (hsp60). Biotinylation of viable yeasts, followed by precipitation with streptavidin-coated beads, and Western blotting with anti-hsp60 demonstrated that hsp60 was on the surface of Hc yeasts. Electron and confocal microscopy revealed that hsp60 resided on the yeast cell wall in discrete clusters. Recombinant hsp60 (rhsp60) inhibited attachment of Hc yeasts to Mphi. Recombinant hsp60 and Abs to CD11b and CD18 inhibited binding of yeasts to Chinese hamster ovary cells transfected with CR3 (CHO3). Polystyrene beads coated with rhsp60 bound to Mphi, and attachment was inhibited by Abs to CD11 and CD18. Freeze/thaw extract (F/TE), a preparation of Hc yeast surface proteins that contained hsp60, inhibited the attachment of Hc yeasts to Mphi. Depletion of hsp60 from F/TE removed the capacity of F/TE to block binding of Hc to Mphi. Interestingly, rhsp60 did not inhibit binding of Hc yeasts to dendritic cells (DC), which recognize Hc via very late Ag 5. Moreover, F/TE inhibited attachment of Hc to DC even when depleted of hsp60. Thus, Hc hsp60 appears to be a major ligand that mediates attachment of Hc to Mphi CD11/CD18, whereas DC recognize Hc via a different ligand(s).
- Published
- 2003
- Full Text
- View/download PDF
39. An unusual initial manifestation of metastatic papillary thyroid carcinoma: radioiodine uptake in lymph node metastatic lesions in a patient with Graves' disease.
- Author
-
Newman SL, Griffith AY, Herbst AB, Yeh IT, and Kukora JS
- Subjects
- Aged, Aged, 80 and over, Carcinoma, Papillary complications, Carcinoma, Papillary surgery, Graves Disease complications, Graves Disease surgery, Humans, Iodine Radioisotopes, Lymph Node Excision, Male, Radionuclide Imaging, Thyroid Neoplasms complications, Thyroid Neoplasms surgery, Thyroidectomy, Carcinoma, Papillary diagnostic imaging, Graves Disease diagnostic imaging, Lymphatic Metastasis diagnostic imaging, Thyroid Neoplasms diagnostic imaging
- Abstract
Objective: To report an unusual manifestation of metastatic papillary thyroid carcinoma with functional metastatic lesions demonstrated by radioiodine scanning and to discuss the relationship of Graves' disease and thyroid carcinoma., Methods: A case report is presented, and the current literature is reviewed., Results: An 82-year-old man had symptoms and laboratory results suggestive of thyrotoxicosis. 123I thyroid uptake scanning demonstrated lateral uptake, which directed attention to the lateral aspect of the neck and resulted in subsequent identification of previously overlooked lymphadenopathy. Total thyroidectomy, including excision of the central compartment and right jugular chain lymph nodes, was performed., Conclusion: In two previous reports of similar cases of metastatic thyroid carcinoma, imaging was done with use of a different scanning agent. To our knowledge, this is the first published case report of functional metastatic lesions imaged with 123I before thyroidectomy. This preoperative finding facilitated clinical management of the patient's thyroid cancer and thyrotoxicosis.
- Published
- 2002
- Full Text
- View/download PDF
40. Candida albicans is phagocytosed, killed, and processed for antigen presentation by human dendritic cells.
- Author
-
Newman SL and Holly A
- Subjects
- Cells, Cultured, Dendritic Cells cytology, Dendritic Cells microbiology, Humans, Macrophages cytology, Macrophages immunology, Macrophages microbiology, Mannose Receptor, Receptors, Cell Surface metabolism, Antigen Presentation immunology, Candida albicans immunology, Dendritic Cells immunology, Lectins, C-Type, Mannose-Binding Lectins, Phagocytosis immunology
- Abstract
Candida albicans is a component of the normal flora of the alimentary tract and also is found on the mucocutaneous membranes of the healthy host. Candida is the leading cause of invasive fungal disease in premature infants, diabetics, and surgical patients, and of oropharyngeal disease in AIDS patients. As the induction of cell-mediated immunity to Candida is of critical importance in host defense, we sought to determine whether human dendritic cells (DC) could phagocytose and degrade Candida and subsequently present Candida antigens to T cells. Immature DC obtained by culture of human monocytes in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4 phagocytosed unopsonized Candida in a time-dependent manner, and phagocytosis was not enhanced by opsonization of Candida in serum. Like macrophages (Mphi), DC recognized Candida by the mannose-fucose receptor. Upon ingestion, DC killed Candida as efficiently as human Mphi, and fungicidal activity was not enhanced by the presence of fresh serum. Although phagocytosis of Candida by DC stimulated the production of superoxide anion, inhibitors of the respiratory burst (or NO production) did not inhibit killing of Candida, even when phagocytosis was blocked by preincubation of DC with cytochalasin D. Further, although apparently only modest phagolysosomal fusion occurred upon DC phagocytosis of Candida, killing of Candida under anaerobic conditions was almost equivalent to killing under aerobic conditions. Finally, DC stimulated Candida-specific lymphocyte proliferation in a concentration-dependent manner after phagocytosis of both viable and heat-killed Candida cells. These data suggest that, in vivo, such interactions between DC and C. albicans may facilitate the induction of cell-mediated immunity.
- Published
- 2001
- Full Text
- View/download PDF
41. Histoplasma capsulatum yeasts are phagocytosed via very late antigen-5, killed, and processed for antigen presentation by human dendritic cells.
- Author
-
Gildea LA, Morris RE, and Newman SL
- Subjects
- Adult, Binding, Competitive immunology, CD18 Antigens physiology, Cell Adhesion immunology, Dendritic Cells metabolism, Dendritic Cells ultrastructure, Histoplasma metabolism, Histoplasma ultrastructure, Humans, Immunophenotyping, Monocytes immunology, Monocytes metabolism, Antigen Presentation immunology, Dendritic Cells immunology, Dendritic Cells microbiology, Histoplasma growth & development, Histoplasma immunology, Phagocytosis immunology, Receptors, Fibronectin physiology
- Abstract
Histoplasma capsulatum (Hc) is a facultative, intracellular parasite of world-wide importance. As the induction of cell-mediated immunity to Hc is of critical importance in host defense, we sought to determine whether dendritic cells (DC) could function as a primary APC for this pathogenic fungus. DC obtained by culture of human monocytes in the presence of GM-CSF and IL-4 phagocytosed Hc yeasts in a time-dependent manner. Upon ingestion, the intracellular growth of yeasts within DC was completely inhibited compared with rapid growth within human macrophages. Electron microscopy of DC with ingested Hc revealed that many of the yeasts were degraded as early as 2 h postingestion. In contrast to macrophages, human DC recognized Hc yeasts via the fibronectin receptor, very late Ag-5, and not via CD18 receptors. DC stimulated Hc-specific lymphocyte proliferation in a concentration-dependent manner after phagocytosis of viable and heat-killed Hc yeasts, but greater proliferation was achieved after ingestion of viable yeasts. These data demonstrate that human DC can phagocytose and degrade a fungal pathogen and subsequently process the appropriate Ags for stimulation of lymphocyte proliferation. In vivo, such interactions between DC and Hc may facilitate the induction of cell-mediated immunity.
- Published
- 2001
- Full Text
- View/download PDF
42. Identification of constituents of human neutrophil azurophil granules that mediate fungistasis against Histoplasma capsulatum.
- Author
-
Newman SL, Gootee L, Gabay JE, and Selsted ME
- Subjects
- Antifungal Agents chemistry, Antifungal Agents pharmacology, Antimicrobial Cationic Peptides, Carrier Proteins pharmacology, Cathepsin G, Cytoplasmic Granules immunology, Histoplasma growth & development, Humans, Microbial Sensitivity Tests, Muramidase pharmacology, Myeloblastin, Neutrophils metabolism, Pancreatic Elastase pharmacology, Serine Endopeptidases pharmacology, Blood Proteins pharmacology, Cathepsins pharmacology, Cytoplasmic Granules chemistry, Defensins pharmacology, Histoplasma drug effects, Membrane Proteins, Neutrophils immunology
- Abstract
Previously we demonstrated that human neutrophils mediate potent and long-lasting fungistasis against Histoplasma capsulatum yeasts and that all of the fungistatic activity resides in the azurophil granules. In the present study, specific azurophil granule constituents with fungistatic activity were identified by incubation with H. capsulatum yeasts for 24 h and by quantifying the subsequent growth of yeasts via the incorporation of [(3)H]leucine. Human neutrophil defensins HNP-1, HNP-2, and HNP-3 inhibited the growth of H. capsulatum yeasts in a concentration-dependent manner with maximum inhibition at 8 microg/ml. At a concentration of 4 microg/ml, all possible paired combinations of defensins exhibited additive fungistatic activity against H. capsulatum yeasts. Cathepsin G and bactericidal-permeability-increasing protein (BPI) also mediated fungistasis against H. capsulatum in a concentration-dependent manner. The fungistatic activities of combinations of cathepsin G and BPI were additive, as were those of combinations of cathepsin G or BPI with HNP-1, HNP-2, and HNP-3. Lysozyme and elastase exhibited modest antifungal activity, and azurocidin and proteinase 3 exhibited no significant fungistasis against H. capsulatum yeasts. Thus, defensins, cathepsin G, and BPI are the major anti-H. capsulatum effector molecules in the azurophil granules of human neutrophils.
- Published
- 2000
- Full Text
- View/download PDF
43. Regulation of the macrophage vacuolar ATPase and phagosome-lysosome fusion by Histoplasma capsulatum.
- Author
-
Strasser JE, Newman SL, Ciraolo GM, Morris RE, Howell ML, and Dean GE
- Subjects
- Animals, Lysosomes enzymology, Lysosomes microbiology, Macrophages microbiology, Mice, Mice, Inbred BALB C, Organelles microbiology, Phagosomes enzymology, Phagosomes microbiology, Histoplasma immunology, Macrophages immunology, Membrane Fusion, Organelles enzymology, Proton-Translocating ATPases biosynthesis, Vacuolar Proton-Translocating ATPases
- Abstract
Histoplasma capsulatum (Hc) maintains a phagosomal pH of about 6.5. This strategy allows Hc to obtain iron from transferrin, and minimize the activity of macrophage (Mo) lysosomal hydrolases. To determine the mechanism of pH regulation, we evaluated the function of the vacuolar ATPase (V-ATPase) in RAW264.7 Mo infected with Hc yeast or the nonpathogenic yeast Saccharomyces cerevisae (Sc). Incubation of Hc-infected Mo with bafilomycin, an inhibitor of the V-ATPase, did not affect the intracellular growth of Hc, nor did it affect the intraphagosomal pH. In contrast, upon addition of bafilomycin, phagosomes containing Sc rapidly changed their pH from 5 to 7. Hc-containing phagosomes had 5-fold less V-ATPase than Sc-containing phagosomes as quantified by immunoelectron microscopy. Furthermore, Hc-containing phagosomes inhibited phagolysosomal fusion as quantified by the presence of acid phosphatase, accumulation of LAMP2, and fusion with rhodamine B-isothiocyanate-labeled dextran-loaded lysosomes. Finally, in Hc-containing phagosomes, uptake of ferritin was equivalent to phagosomes containing Sc, indicating that Hc-containing phagosomes have full access to the early "bulk flow" endocytic pathway. Thus, Hc yeasts inhibit phagolysosomal fusion, inhibit accumulation of the V-ATPase in the phagosome, and actively acidify the phagosomal pH to 6.5 as part of their strategy to survive in Mo phagosomes.
- Published
- 1999
44. Macrophages in host defense against Histoplasma capsulatum.
- Author
-
Newman SL
- Subjects
- Animals, Histoplasma physiology, Histoplasmosis microbiology, Humans, Macrophage Activation, Macrophages microbiology, Mice, Mycobacterium immunology, Mycobacterium physiology, Phagocytosis, Phagosomes physiology, Respiratory Burst, Histoplasma immunology, Histoplasmosis immunology, Macrophages immunology
- Abstract
Macrophages function in both innate and cell-mediated immunity in host defense against pathogenic fungi. They initially serve as a protected environment in which the primary fungal pathogen Histoplasma capsulatum multiplies and disseminates from the lung to other organs. Upon induction of cell-mediated immunity, cytokines activate macrophages to destroy the yeasts and thus remove them from the host.
- Published
- 1999
- Full Text
- View/download PDF
45. Modulation of the effector function of human macrophages for Histoplasma capsulatum by HIV-1. Role of the envelope glycoprotein gp120.
- Author
-
Chaturvedi S and Newman SL
- Subjects
- Blood Proteins drug effects, Cell Differentiation drug effects, Cells, Cultured, Dose-Response Relationship, Drug, HIV-1 metabolism, Humans, Macrophages microbiology, Macrophages virology, Time Factors, HIV Envelope Protein gp120 physiology, HIV-1 physiology, Histoplasma immunology, Macrophages immunology, Macrophages metabolism, Phagocytosis
- Abstract
We have demonstrated that monocyte-derived macrophages (Mphi) from HIV+ individuals are deficient in their capacity to phagocytose Histoplasma capsulatum (Hc) yeasts, and are more permissive for the intracellular growth of Hc. To determine whether these defects in Mphi function were caused by HIV infection of the Mphi and/or by pathological events associated with HIV infection, cultured normal human Mphi were infected with the HIV-1BaL strain. Virus production, quantified by reverse transcriptase activity and p24 antigen, was evident on day 8 after infection and peaked on day 16. On days 12, 16, and 20 after infection, HIV-1-infected Mphi were deficient in their capacity to recognize and bind Hc yeasts compared with control Mphi, and also were more permissive for the intracellular growth of Hc. Culture of normal Mphi with the envelope glycoprotein gp120 inhibited phagocytosis of Hc yeasts by Mphi in a concentration-dependent manner, but did not cause more rapid intracellular growth of Hc. Normal Mphi cultured in the serum of HIV+ individuals with impaired Mphi function subsequently were deficient in their capacity to phagocytose Hc yeasts, and were more permissive for the intracellular growth of yeasts compared with Mphi cultured in normal serum. Conversely, culture of normal Mphi in the serum of HIV+ patients with normal Mphi function did not affect the interaction of Hc yeasts with Mphi. Moreover, when Mphi from HIV+ individuals that were initially defective in host defense against Hc were cultured in normal HIV- serum, normal Mphi function was demonstrated. Adsorption of gp120 from the serum of two HIV+ patients removed the capacity of the serum to cause a Mphi defect in phagocytosis of Hc, but had no effect on the capacity of the serum to cause accelerated intracellular growth. These data demonstrate that observed defects in Mphi interaction with Hc yeasts may be caused by gp120 and other, as yet unknown serum component(s) probably released into serum by HIV-infected cells.
- Published
- 1997
- Full Text
- View/download PDF
46. Activation of human macrophage fungistatic activity against Histoplasma capsulatum upon adherence to type 1 collagen matrices.
- Author
-
Newman SL, Gootee L, Kidd C, Ciraolo GM, and Morris R
- Subjects
- Cell Adhesion immunology, Cytokines pharmacology, Gels, Histoplasma immunology, Histoplasmosis immunology, Humans, Intracellular Fluid immunology, Intracellular Fluid metabolism, Intracellular Fluid microbiology, Iron metabolism, Macrophages physiology, Phagosomes immunology, Phagosomes microbiology, Collagen physiology, Histoplasma growth & development, Histoplasmosis microbiology, Histoplasmosis prevention & control, Macrophage Activation, Macrophages immunology, Macrophages microbiology
- Abstract
Human monocyte/macrophages (Mphi) were adhered to extracellular matrix proteins, and the intracellular growth of Histoplasma capsulatum (Hc) yeasts were quantified and compared with their growth in Mphi adhered to plastic. Freshly isolated monocytes and cultured monocyte/derived Mphi adhered to type 1 collagen gels, but not to nongelled collagen-, fibronectin-, laminin-, or vitronectin-coated surfaces, demonstrated significant fungistatic activity against Hc yeasts. Activation of Mphi developed immediately upon adherence to the collagen matrices (1 h) and did not require additional time in culture. In addition, many of the yeasts were digested by 24 h postinfection. Mphi adhered to collagen maintained their fungistatic activity for up to 4 days, during which time monolayers cultured on plastic were destroyed. Culture of Mphi in the presence of IFN-gamma or TNF-alpha for 24 h before infection did not augment the fungistatic activity of collagen-adherent Mphi. Likewise, culture of monocytes on collagen gels with IL-3, granulocyte-Mphi CSF (GM-CSF) or Mphi CSF (M-CSF) for 7 days did not enhance Mphi fungistatic activity above that obtained by monocytes cultured on collagen alone. The mechanism(s) of Mphi-mediated fungistasis was not associated with production of toxic oxygen radicals, nitric oxide, or the restriction of intracellular iron. However, experiments with horseradish peroxidase-labeled gold colloids and immunoelectron microscopy demonstrated that phagolysosomal fusion, which is minimal in Hc-infected Mphi adhered to plastic, is enhanced significantly at both 1 h and 24 h postinfection in Mphi adhered to collagen matrices. These data suggest that in vivo, matrix-bound Mphi may express a previously unrecognized antifungal activity that proceeds in the absence of exogenous cytokines and is mediated, in part, by overcoming the capacity of Hc yeasts to inhibit Mphi phagolysosomal fusion.
- Published
- 1997
47. Role of cell-surface molecules of Blastomyces dermatitidis in host-pathogen interactions.
- Author
-
Klein BS and Newman SL
- Subjects
- Amino Acid Sequence, Animals, Bacterial Proteins genetics, Bacterial Proteins physiology, Blastomyces genetics, Blastomyces physiology, Cell Membrane physiology, Fungal Proteins genetics, Fungal Proteins immunology, Fungal Proteins physiology, Glycoproteins genetics, Glycoproteins immunology, Glycoproteins physiology, Humans, Models, Biological, Molecular Sequence Data, Virulence physiology, Adhesins, Bacterial, Blastomyces pathogenicity, Blastomycosis etiology
- Abstract
The fungal pathogen Blastomyces dermatitidis produces an adhesin (WI-1) in yeast stages, which contains repetitive regions that bind host-cell receptors. Adhesin and glucan may modulate fungal interactions with macrophages; their level of expression is altered in hypovirulent mutants. Adhesin is also involved in immune responses, and may be important in eliciting the clearance of the fungus.
- Published
- 1996
- Full Text
- View/download PDF
48. Oxidative killing of Cryptococcus neoformans by human neutrophils. Evidence that fungal mannitol protects by scavenging reactive oxygen intermediates.
- Author
-
Chaturvedi V, Wong B, and Newman SL
- Subjects
- Cell-Free System immunology, Cryptococcus neoformans chemistry, Humans, Neutrophils drug effects, Oxidation-Reduction drug effects, Phagocytosis drug effects, Respiratory Burst drug effects, Cryptococcus neoformans immunology, Mannitol pharmacology, Neutrophils immunology, Neutrophils metabolism, Reactive Oxygen Species metabolism, Respiratory Burst immunology
- Abstract
Polymorphonuclear neutrophils (PMN) kill Cryptococcus neoformans (Cn) by oxidative mechanisms, but the roles of various reactive oxygen intermediates (ROIs) are not known. We used a mannitol low-producing Cn mutant (Cn MLP) and its wild-type parent (Cn H99) to examine the role of ROIs distal to H2O2 in PMN killing and to determine whether mannitol produced by Cn protects the fungus against ROIs. At PMN:Cn cell ratios of 1:1, 10:1, and 100:1, PMN killed significantly more Cn MLP than Cn H99 cells after 2 and 4 h (p less than 0.05). Superoxide dismutase and the hydroxyl radical (OH.) scavengers mannitol and DMSO inhibited killing of both strains (p less than 0.05), but catalase did not. Cn H99 and Cn MLP stimulated PMN to produce similar amounts of O2- and H2O2. In contrast, Cn MLP stimulated greater luminol-dependent chemiluminescence than did Cn H99 (p less than 0.05). Finally, H2O2 alone killed similar numbers of Cn H99 and Cn MLP cells, but oxidants generated by FeSO4 (1 microM), H2O2 (10 microM), and iodide (1 to 3 microM) killed significantly more Cn MLP than Cn H99 cells in 1 h (p less than 0.05). Mannitol, DMSO, and catalase completely inhibited killing of both Cn strains by this cellfree system, but superoxide dismutase did not. These results suggest that 1) distal ROIs such as OH. and HOCI are key effector molecules against Cn, and 2) mannitol produced by Cn may protect against oxidative killing by scavenging distal ROIs.
- Published
- 1996
49. Inhibition of growth of Histoplasma capsulatum yeast cells in human macrophages by the iron chelator VUF 8514 and comparison of VUF 8514 with deferoxamine.
- Author
-
Newman SL, Gootee L, Stroobant V, van der Goot H, and Boelaert JR
- Subjects
- 2,2'-Dipyridyl pharmacology, Cell Division drug effects, Culture Media, Histoplasma drug effects, Humans, In Vitro Techniques, Macrophages drug effects, 2,2'-Dipyridyl analogs & derivatives, Deferoxamine pharmacology, Histoplasma growth & development, Iron Chelating Agents pharmacology, Macrophages microbiology
- Abstract
Histoplasma capsulatum requires intracellular iron to survive and multiply within human and murine macrophages (M phi). Thus, iron chelators may be useful compounds in the treatment of histoplasmosis. In the present study we compared the efficacies of five different iron chelators with deferoxamine (DEF) for their capacity to inhibit the growth of H. capsulatum yeast cells in culture medium and within human M phi. Of the agents tested, only one, VUF 8514, a 2,2'-bipyridyl analog, was found to be effective. VUF 8514 inhibited the growth of yeast cells in tissue culture medium and within M phi in a dose-response fashion. In tissue culture medium, the 50% effective dose (ED50) of VUF 8514 was 30 nM and the ED50 of DEF was 1 mM. In human M phi, the ED50 of VUF 8514 was 520 nM and the ED50 of DEF was 4 mM. Thus, VUF 8514 was effective at a concentration 7.7 x 10(3)-fold lower than DEF in inhibiting the growth of yeast cells in M phi. Inhibition of the intracellular growth of yeast cells by VUF 8514 was reversed by holotransferrin and iron nitriloacetate, an iron compound that is soluble at neutral to alkaline pH. Thus, VUF 8514 inhibits the intracellular growth of yeast cells by acting as an iron chelator rather than through its capacity as a weak base. These data suggest that the hydroxamic acid siderophore of H. capsulatum yeast cells competes successfully for iron against some iron chelators but not others and that VUF 8514 may be a potential therapeutic agent for the treatment of histoplasmosis.
- Published
- 1995
- Full Text
- View/download PDF
50. Myelinogenic potential of an immortalized oligodendrocyte cell line.
- Author
-
Newman SL, Weikle AA, Neuberger TJ, and Bigbee JW
- Subjects
- Animals, Blotting, Western, Cell Division, Cell Line, Ganglia, Spinal cytology, Ganglia, Spinal metabolism, Gene Expression physiology, Immunoblotting, Immunohistochemistry, Microscopy, Electron, Myelin Basic Protein biosynthesis, Myelin Sheath ultrastructure, Neurites physiology, Neurites ultrastructure, Oligodendroglia ultrastructure, Proteolipids biosynthesis, Rats, Thymidine metabolism, Myelin Sheath metabolism, Oligodendroglia metabolism
- Abstract
The myelinogenic potential of an oligodendrocyte cell line (N20.1) immortalized by transformation with a temperature-sensitive retrovirus (Verity et al., J Neurochem 60:577-587, 1993) has been evaluated in a co-culture system utilizing dorsal root ganglion neurons. When N20.1 cells were placed in co-culture with dorsal root ganglion neurons at 39 degrees C, the temperature at which TAg expression is decreased relative to that in cells maintained at 34 degrees C, there was a dramatic decrease in the N20.1 proliferation rate compared to cells maintained in the absence of neurons at either temperature. This decrease in proliferation was observed within 3 days of co-culture and appeared to precede a further decrease in TAg expression that occurred with time in response to the neurons. In co-cultures the immunoreactivity of N20.1 cells for galactocerebroside increased with time, and the cells appeared to establish contact with neurites and initiate formation of membranous sheets. When the duration of co-culture was extended to 52 days, myelin-like figures were noted by electron microscopy. Thus, the extent of N20.1 differentiation is dependent on the presence of neurons and the duration of co-culture. This culture system represents a potentially powerful tool for the study of neuronal-glial interactions influencing myelinogenesis and remyelination.
- Published
- 1995
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.