206 results on '"John Papadimitriou"'
Search Results
2. Pathogenesis and clinical management of obesity-related knee osteoarthritis: Impact of mechanical loading
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Lianzhi Chen, Jessica Jun Yi Zheng, Guangyi Li, Jun Yuan, Jay R. Ebert, Hengyuan Li, John Papadimitriou, Qingwen Wang, David Wood, Christopher W. Jones, and Minghao Zheng
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Biomechanics ,Clinical management ,Mechanical loading ,Obesity ,Osteoarthritis ,Pathogenesis ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Summary: Obesity-related osteoarthritis (OA) is a complex, multifactorial condition that can cause significant impact on patients’ quality of life. Whilst chronic inflammation, adipocytokines and metabolic factors are considered to be important pathogenic factors in obesity related OA, there has been limited investigation into the biomechanical impact of obesity on OA development. This review aims to demonstrate that mechanical factors are the major pathological cause of obesity-related OA. The effect of obesity on pathological changes to the osteochondral unit and surrounding connective tissues in OA is summarized, as well as the impact of obesity-related excessive and abnormal joint loading, concomitant joint malalignment and muscle weakness. An integrated therapeutic strategy based on this multi-factorial presentation is presented, to assist in the management of obesity related OA. The translational potential of this article: Despite the high prevalence of obesity-related OA, there is no specific guideline available for obesity-related OA management. In this review, we demonstrated the pathological changes of obesity-related OA and summarized the impact of biomechanical factors by proposing a hypothetical model of obesity-related OA change. Therapeutic strategies based on adjusting abnormal mechanical effects are presented to assist in the management of obesity-related OA.
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- 2020
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3. Loss of the RNA-binding protein TACO1 causes late-onset mitochondrial dysfunction in mice
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Tara R. Richman, Henrik Spåhr, Judith A. Ermer, Stefan M. K. Davies, Helena M. Viola, Kristyn A. Bates, John Papadimitriou, Livia C. Hool, Jennifer Rodger, Nils-Göran Larsson, Oliver Rackham, and Aleksandra Filipovska
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Science - Abstract
Mutations in the translational activator of cytochrome c oxidase subunit I (TACO1) causes cytochrome c oxidase deficiency and Leigh Syndrome in patients. Here, the authors characterize mice with a mutation that causes lack of TACO1 expression, identifying a mouse model that could be useful for preclinical trials.
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- 2016
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4. Actin nemaline myopathy mouse reproduces disease, suggests other actin disease phenotypes and provides cautionary note on muscle transgene expression.
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Gianina Ravenscroft, Connie Jackaman, Caroline A Sewry, Elyshia McNamara, Sarah E Squire, Allyson C Potter, John Papadimitriou, Lisa M Griffiths, Anthony J Bakker, Kay E Davies, Nigel G Laing, and Kristen J Nowak
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Medicine ,Science - Abstract
Mutations in the skeletal muscle α-actin gene (ACTA1) cause congenital myopathies including nemaline myopathy, actin aggregate myopathy and rod-core disease. The majority of patients with ACTA1 mutations have severe hypotonia and do not survive beyond the age of one. A transgenic mouse model was generated expressing an autosomal dominant mutant (D286G) of ACTA1 (identified in a severe nemaline myopathy patient) fused with EGFP. Nemaline bodies were observed in multiple skeletal muscles, with serial sections showing these correlated to aggregates of the mutant skeletal muscle α-actin-EGFP. Isolated extensor digitorum longus and soleus muscles were significantly weaker than wild-type (WT) muscle at 4 weeks of age, coinciding with the peak in structural lesions. These 4 week-old mice were ~30% less active on voluntary running wheels than WT mice. The α-actin-EGFP protein clearly demonstrated that the transgene was expressed equally in all myosin heavy chain (MHC) fibre types during the early postnatal period, but subsequently became largely confined to MHCIIB fibres. Ringbinden fibres, internal nuclei and myofibrillar myopathy pathologies, not typical features in nemaline myopathy or patients with ACTA1 mutations, were frequently observed. Ringbinden were found in fast fibre predominant muscles of adult mice and were exclusively MHCIIB-positive fibres. Thus, this mouse model presents a reliable model for the investigation of the pathobiology of nemaline body formation and muscle weakness and for evaluation of potential therapeutic interventions. The occurrence of core-like regions, internal nuclei and ringbinden will allow analysis of the mechanisms underlying these lesions. The occurrence of ringbinden and features of myofibrillar myopathy in this mouse model of ACTA1 disease suggests that patients with these pathologies and no genetic explanation should be screened for ACTA1 mutations.
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- 2011
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5. Expression in skin biopsies supports genetic evidence linking CAMKK2, P2X7R and P2X4R with HIV-associated sensory neuropathy
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Jessica Gaff, Fitri Octaviana, Connie Jackaman, Peter Kamerman, John Papadimitriou, Silvia Lee, Jenjira Mountford, and Patricia Price
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Cellular and Molecular Neuroscience ,Neurology ,Virology ,Neurology (clinical) - Abstract
HIV-associated sensory neuropathy (HIV-SN) affects 14–38% of HIV+ individuals stable on therapy with no neurotoxic drugs. Polymorphisms in CAMKK2, P2X7R and P2X4R associated with altered risk of HIV-SN in Indonesian and South African patients. The role of CaMKK2 in neuronal repair makes this an attractive candidate, but a direct role for any protein is predicated on expression in affected tissues. Here, we describe expression of CaMKK2, P2X7R and P2X4R proteins in skin biopsies from the lower legs of HIV+ Indonesians with and without HIV-SN, and healthy controls (HC). HIV-SN was diagnosed using the Brief Peripheral Neuropathy Screen. Biopsies were stained to detect protein gene product 9.5 on nerve fibres and CaMKK2, P2X7R or P2X4R, and were examined using 3-colour sequential scanning confocal microscopy. Intraepidermal nerve fibre densities (IENFD) were lower in HIV+ donors than HC and correlated directly with nadir CD4 T-cell counts (r = 0.69, p = 0.004). However, IENFD counts were similar in HIV-SN+ and HIV-SN− donors (p = 0.19) and so did not define neuropathy. CaMKK2+ cells were located close to dermal and epidermal nerve fibres and were rare in HC and HIV-SN− donors, consistent with a role for the protein in nerve damage and/or repair. P2X7R was expressed by cells in blood vessels of HIV-SN− donors, but rarely in HC or HIV-SN+ donors. P2X4R expression by cells in the epidermal basal layer appeared greatest in HIV-SN+ donors. Overall, the differential expression of CaMKK2, P2X7R and P2X4R supports the genetic evidence of a role for these proteins in HIV-SN.
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- 2023
6. Distinct differences between calvarial and long bone osteocytes in cell morphologies, gene expression and aging responses
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Minhao Gao, Bin Zhu, Jing Fan, Youshui Gao, Feng Xue, Guangyi Li, Alysia Hubbard, Xiangrong Gao, Jing Sun, Jing Ling, Longxiang Cao, Delin Liu, Jun Yuan, Qing Jiang, John Papadimitriou, Weiguo Zou, Jian Q. Feng, Liu Yang, Changqing Zhang, Junjie Gao, and Minghao Zheng
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Cell Biology ,Molecular Biology ,Biochemistry - Published
- 2023
7. Author response for 'Distinct differences between calvarial and long bone osteocytes in cell morphologies, gene expressions and aging responses'
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null Minhao Gao, null Bin Zhu, null Jing Fan, null Youshui Gao, null Feng Xue, null Guangyi Li, null Alysia Hubbard, null Xiangrong Gao, null Jing Sun, null Jing Ling, null Longxiang Cao, null Delin Liu, null Jun Yuan, null Qing Jiang, null John Papadimitriou, null Weiguo Zou, null Jian Q Feng, null Liu Yang, null Changqing Zhang, null Junjie Gao, and null Minghao Zheng
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- 2023
8. Regulation of Blood-Brain Barrier Integrity by a Subset of Astrocytes Through Mitochondrial Transfer
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De-Lin Liu, Hao Li, Peng Liao, You-Shui Gao, Yi-Gang Huang, Hao Zhou, Lin-Jing Shi, John Papadimitriou, Yao Zong, Jun Yuan, Peilin Chen, Zi-Ming Chen, Peng Ding, Yong-Qiang Zheng, Changqing Zhang, Ming Hao Zheng, and Jun-Jie Gao
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
9. Oncocytic Lesion or an Atypical Epithelioid Vascular Tumor of Unknown Biologic Potential: A Rare Diagnostic Dilemma
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Dr. Sonia Sanadhya, Dr. Anthony Chi, Dr. Robert Dayse, Dr. Zaid Khoury, Dr. Manar Elnaggar, Dr. Ioana Ghita, Prof. John Papadimitriou, Dr. Robert Foss, Prof. Rania Younis, and Prof. John Basile
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Radiology, Nuclear Medicine and imaging ,Dentistry (miscellaneous) ,Surgery ,Oral Surgery ,Pathology and Forensic Medicine - Published
- 2022
10. Author response for 'Severe congenital cutis laxa: Identification of novel homozygous LOX gene variants in two families'
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John Papadimitriou, Aude Beyens, Fiona Haslam McKenzie, Gareth Baynam, Gareth Jevon, Kym Mina, Jan E. Dickinson, Birgitte Rode Diness, Bert Callewaert, Jesper Steensberg, and Jakob Ek
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Genetics ,medicine ,Identification (biology) ,Biology ,medicine.disease ,Gene ,Cutis laxa - Published
- 2021
11. Severe congenital cutis laxa: Identification of novel homozygous LOX gene variants in two families
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Gareth Baynam, Bert Callewaert, John Papadimitriou, Jakob Ek, Jesper Steensberg, Fiona Haslam McKenzie, Kym Mina, Aude Beyens, Jan E. Dickinson, Gareth Jevon, and Birgitte Rode Diness
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Adult ,Male ,Pathology ,medicine.medical_specialty ,Mutation, Missense ,Lysyl oxidase ,Cutis Laxa ,Protein-Lysine 6-Oxidase ,Pregnancy ,Ectasia ,Genetics ,Medicine ,Gene family ,Humans ,Abnormalities, Multiple ,Genetics (clinical) ,Exome sequencing ,biology ,business.industry ,Homozygote ,medicine.disease ,Phenotype ,Pedigree ,Osteogenesis imperfecta ,Face ,biology.protein ,Female ,business ,Elastin ,Cutis laxa - Abstract
We report three babies from two families with a severe lethal form of congenital cutis laxa. All three had redundant and doughy-textured skin and two siblings from one family had facial dysmorphism. Echocardiograms showed thickened and poorly contractile hearts, arterial dilatation and tortuosity. Post-mortem examination in two of the babies further revealed widespread ectasia and tortuosity of medium and large sized arteries, myocardial hypertrophy, rib and skull fractures. The presence of fractures initially suggested a diagnosis of osteogenesis imperfecta. Under light microscopy bony matrices were abnormal and arterial wall architecture was grossly abnormal showing fragmented elastic fibres. Molecular analysis of known cutis laxa genes did not yield any pathogenic defects. Whole exome sequencing of DNA following informed consent identified two separate homozygous variants in the LOX (Lysyl Oxidase) gene. LOX belongs to the 5-lysyl oxidase gene family involved in initiation of cross-linking of elastin and collagen. A mouse model of a different variant in this gene recapitulates the phenotype seen in the three babies. Our findings suggest that the LOX gene is a novel cause of severe congenital cutis laxa with arterial tortuosity, bone fragility and respiratory failure.
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- 2021
12. The histological stromal inflammatory subtypes and its transcriptional immune signature defined in oral squamous cell carcinoma with the soluble Semaphorin 4D immune biomarker
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Dr. Ioana Ghita, Prof. Rania Younis, Dr. Manar Elnaggar, Prof. Risa Chaisuparat, Prof. John Papadimitriou, Prof. Soren Bentzen, and Prof. Joshua Lubek
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Radiology, Nuclear Medicine and imaging ,Dentistry (miscellaneous) ,Surgery ,Oral Surgery ,Pathology and Forensic Medicine - Published
- 2022
13. Superficial CD34-positive fibroblastic tumour: report of two new cases
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John Papadimitriou, Daniel D. Wong, Benjamin A. Wood, Peter Robbins, and Shona Hendry
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Pathology ,medicine.medical_specialty ,Text mining ,business.industry ,medicine ,MEDLINE ,CD34 ,business ,Pathology and Forensic Medicine - Published
- 2015
14. Response Gene to Complement -32 exerts proinflammatory and profibrotic effects in immune complex mediated glomerulonephritis
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Violeta Rus, Alexandru Tatomir, Vinh Nguyen, Ana Talpos-Caia, John Papadimitriou, Sergei Atamas, Irina Luzina, Sun-Sang J Sung, Tudor Badea, and Horea Rus
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Immunology ,Immunology and Allergy - Abstract
Response Gene to Complement (RGC)-32 is a cell cycle regulator induced by complement activation, growth factors and cytokines. RGC-32 mediates TGF-β dependent profibrotic pathways, while in immune cells promotes the differentiation of Th17 cells in vitro and in vivo. RGC-32 expression is increased in tubules and glomerular infiltrating cells in kidney biopsies of patients with lupus nephritis. We used the nephrotoxic nephritis (NTN) mouse model to assess whether RGC-32 plays a local role in immune complex mediated glomerulonephritis (GN). NTN was induced in WT and RGC-32−/− mice. Proteinuria, blood urea nitrogen and kidney histopathology were determined to assess kidney function and damage, IgG and C3 deposition. Single cell suspension of kidneys and spleens were analyzed by flow cytometry. Expression of IL-17A, collagen I, III and IV was determined by RT-PCR. RGC-32−/− mice exhibit attenuated renal damage as shown by decreased proteinuria and glomerular scores, as well as decreased frequency of infiltrating PMN and decreased mRNA expression for IL-17A, collagen I, III and IV compared to WT mice. RGC-32 deficiency did not interfere with the induction of NTN as mouse anti-sheep IgG titers, percentage of splenic germinal center B cells, plasma cells, effector CD4+ T cells, Tregs, IL-17A, IFNg secreting cells and kidney deposition of autologous antibodies did not differ between RGC-32−/− and WT mice. These results suggest that RGC-32 contributes to the pathogenesis of immune complex mediated GN by promoting proinflammatory and profibrotic pathways. These data support further efforts to examine the mechanisms by which RGC-32 modulates these pathways and suggest that RGC-32 is a potential novel therapeutic target in the treatment of LN.
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- 2019
15. Fatal persistence of West Nile virus subtype Kunjin in the brains of flavivirus resistant mice
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Nadezda Urosevic, John Papadimitriou, and Rafidah Hanim Shueb
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Cancer Research ,viruses ,Congenic ,Virulence ,Biology ,Virus Replication ,Flavivirus Infections ,Pathogenesis ,Mice ,Mice, Congenic ,Virology ,Immunopathology ,medicine ,Animals ,Humans ,Mice, Inbred C3H ,Tumor Necrosis Factor-alpha ,Brain ,medicine.disease ,biology.organism_classification ,Immunity, Innate ,Titer ,Flavivirus ,Infectious Diseases ,Viral replication ,Interferon Type I ,Immunology ,Disease Susceptibility ,West Nile virus ,Encephalitis - Abstract
Flaviviruses cause febrile illnesses in humans that may progress to encephalitis and death. Both viral and host factors determine the level of virus replication and outcome of infection. In mice, genetically determined resistance conferred by the flavivirus resistance locus (Flv) is responsible for the restricted flavivirus replication and prevention of disease development. Majority of flaviviruses express significant virulence, replicate to high titers and cause high mortality in susceptible mice, while congenic resistant mice endure the infection, show significantly reduced levels of virus replication and remain healthy. In contrast, infection with West Nile virus subtype Kunjin (KUNV) causes morbidity and fatal outcomes even in mice that are naturally resistant to flaviviruses. There are two possible mechanisms that could account for such an unforeseen virulence of KUNV in resistant mice: (a) an abrogation of Flv-controlled natural resistance leading to high virus replication, or (b) massive virus-induced immunopathology in the brain. To identify the cause(s) of fatality of KUNV infection, disease progression, virus replication and brain histopathology were studied in parallel in resistant and congenic susceptible mice. While KUNV replicated to high titers causing early fatalities in susceptible mice, it showed only reduced replication associated with the delayed morbidity in resistant mice indicating no abrogation of the Flv resistance. No evidence of excessive immune cell infiltration and tissue damage following KUNV infection were found. However, incomplete KUNV clearance not previously described was perceived as an important source of pathogenesis in resistant mice.
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- 2011
16. Public awareness and perceptions of carbon dioxide capture and storage (CCS): Insights from surveys administered to representative samples in six European countries
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Bart W. Terwel, Carmencita Constantin, Alexandra Dudu, John Papadimitriou, Diana Schumann, Constantin Stefan Sava, Oana C. Nihfidov, Katja Pietzner, Emma ter Mors, Dancker D.L. Daamen, Diana Cismaru, Sorin Anghel, Irene R. Samoila, Michael H. Stephenson, Hans Yngvar Torvatn, Loredana Ivan, David Reiner, Sturle Danielsen Tvedt, Angelos Markos, Andrea Esken, Vassiliki Gemeni, Claudia E. Tomescu, Robert Næss, Glenn Kristiansen, Nikolaos Koukouzas, and Fotini Ziogou
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business.industry ,Communication ,media_common.quotation_subject ,Environmental resource management ,Awareness ,Environmental economics ,Capture and storage technologies ,Experimental research ,CCS ,Europe ,Knowledge ,Energy(all) ,TheoryofComputation_LOGICSANDMEANINGSOFPROGRAMS ,Perception ,Communication methods ,CO2 ,Public awareness ,business ,Netherlands ,media_common - Abstract
The representative survey studies provide a comprehensive database on the public awareness and perception of CCS in six selected European countries. Our results provide insights into the public understanding and knowledge of energy related issues and CCS topics. The embedded experimental research provides insights into how information affects CCS perceptions. The results discuss implications for CCS communication methods.
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- 2011
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17. Bronchial epithelial-myoepithelial tumour: a case report and review of the literature
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Anupam Naran, John Papadimitriou, Dominic V. Spagnolo, Pierre Filion, and Daniel D. Wong
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Pathology ,medicine.medical_specialty ,medicine.anatomical_structure ,medicine ,Myoepithelial cell ,Neoplasm ,Myoepithelial tumour ,Biology ,medicine.disease ,Epithelium ,Pathology and Forensic Medicine - Abstract
Sir,Epithelial-myoepithelial tumour (EMT) is an uncommon neoplasm composed of myoepithelial cells with varying amounts of duct-forming epithelium. It most frequently occurs in the salivary glands a...
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- 2010
18. Has Gallo proven the role of HIV in AIDS?
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Eleni Papadopulos-Eleopulos, John Papadimitriou, and Valendar F. Turner
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Isolation (health care) ,biology ,business.industry ,viruses ,Human immunodeficiency virus (HIV) ,virus diseases ,medicine.disease ,biology.organism_classification ,medicine.disease_cause ,Virology ,Virus ,Retrovirus ,Acquired immunodeficiency syndrome (AIDS) ,Immunology ,medicine ,business - Abstract
The evidence that Robert Gallo and his colleagues presented on 4th May 1984 regarding HTLV-III (HIV) isolation and the role of HIV in the pathogenesis of AIDS is critically analysed. It is concluded that the evidence does not constitute proof of the isolation of a retrovirus, that the virus is exogenous, or that the virus is causally related to AIDS.
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- 2009
19. Rescue of skeletal muscle α-actin–null mice by cardiac (fetal) α-actin
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Lisa M. Griffiths, Grant Morahan, Esther Lim, Kelly M. Crawford, Yun Shen, Nigel G. Laing, Gianina Ravenscroft, Kristen J. Nowak, Sophie Clément, Victoria A. Fabian, A Potter, Elizabeth Baker, Sarah E. Squire, Aleksandra Filipovska, John Papadimitriou, Stefan M.K. Davies, Anthony J. Bakker, Connie Jackaman, Kay E. Davies, James L. Lessard, and Caroline Sewry
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Genetically modified mouse ,medicine.medical_specialty ,Offspring ,Biology ,Article ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,Protein Isoforms ,Muscle, Skeletal ,Research Articles ,Actin ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,Fetus ,Heart development ,Gene Expression Profiling ,Myocardium ,Skeletal muscle ,Heart ,Cell Biology ,Actins ,Gene expression profiling ,Endocrinology ,medicine.anatomical_structure ,Knockout mouse ,030217 neurology & neurosurgery - Abstract
Skeletal muscle α-actin (ACTA1) is the major actin in postnatal skeletal muscle. Mutations of ACTA1 cause mostly fatal congenital myopathies. Cardiac α-actin (ACTC) is the major striated actin in adult heart and fetal skeletal muscle. It is unknown why ACTC and ACTA1 expression switch during development. We investigated whether ACTC can replace ACTA1 in postnatal skeletal muscle. Two ACTC transgenic mouse lines were crossed with Acta1 knockout mice (which all die by 9 d after birth). Offspring resulting from the cross with the high expressing line survive to old age, and their skeletal muscles show no gross pathological features. The mice are not impaired on grip strength, rotarod, or locomotor activity. These findings indicate that ACTC is sufficiently similar to ACTA1 to produce adequate function in postnatal skeletal muscle. This raises the prospect that ACTC reactivation might provide a therapy for ACTA1 diseases. In addition, the mouse model will allow analysis of the precise functional differences between ACTA1 and ACTC.
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- 2009
20. Structure and Function in Myocardial Hypertrophy
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John Papadimitriou, Roger R. Taylor, and Barry E. Hopkins
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medicine.medical_specialty ,Text mining ,business.industry ,Internal medicine ,Myocardial hypertrophy ,Cardiology ,Medicine ,business ,Structure and function - Published
- 2015
21. Cyclical Inguinal Keratoderma: A New Clinical Entity or a Variant of Pityriasis Rubra Pilaris?
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Janet Kim, Sujith Prasad Kumarasinghe, Lawrence Yu, and John Papadimitriou
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Treatment outcome ,Dermatology ,Thigh ,medicine.disease ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Scrotum ,Biopsy ,medicine ,Pityriasis rubra pilaris ,business ,Keratoderma - Published
- 2016
22. The biocompatibility of silk fibroin and acellular collagen scaffolds for tissue engineering in the ear
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Bing Mei Teh, Robert J. Marano, Sharon L. Redmond, John Papadimitriou, Yan Wang, Rodney J. Dilley, Yi Shen, Sheng Yan, Minghao Zheng, and Marcus D. Atlas
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musculoskeletal diseases ,Male ,Scaffold ,Materials science ,Tympanic Membrane ,Biocompatibility ,Swine ,Biomedical Engineering ,Silk ,Fibroin ,Bioengineering ,Biocompatible Materials ,Otoscopy ,Biomaterials ,Rats, Sprague-Dawley ,fluids and secretions ,Tissue engineering ,Fibrosis ,Osteogenesis ,medicine ,Animals ,Tympanic Membrane Perforation ,Inflammation ,Tissue Engineering ,Tissue Scaffolds ,Histology ,Ear ,medicine.disease ,Bombyx ,Immunohistochemistry ,Rats ,medicine.anatomical_structure ,Middle ear ,Collagen ,Fibroins ,Gels ,Biomedical engineering - Abstract
Recent experimental studies have shown the suitability of silk fibroin scaffold (SFS) and porcine-derived acellular collagen I/III scaffold (ACS) as onlay graft materials for tympanic membrane perforation repair. The aims of this study were to further characterize and evaluate the in vivo biocompatibility of SFS and ACS compared with commonly used materials such as Gelfoam and paper in a rat model. The scaffolds were implanted in subcutaneous (SC) tissue and middle ear (ME) cavity followed by histological and otoscopic evaluation for up to 26 weeks. Our results revealed that SFS and ACS were well tolerated and compatible in rat SC and ME tissues throughout the study. The tissue response adjacent to the implants evaluated by histology and otoscopy showed SFS and ACS to have a milder tissue response with minimal inflammation compared to that of paper. Gelfoam gave similar results to SFS and ACS after SC implantation, but it was found to be associated with pronounced fibrosis and osteoneogenesis after ME implantation. It is concluded that SFS and ACS both were biocompatible and could serve as potential alternative scaffolds for tissue engineering in the ear.
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- 2014
23. Morphological features of Murray Valley encephalitis virus infection in the central nervous system of swiss mice
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Peter Mcminn, Terry Robertson, John Papadimitriou, Tulene Kendrick, Michael Abdo, and Vance B. Matthews
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Pathology ,medicine.medical_specialty ,education.field_of_study ,Necrosis ,Endoplasmic reticulum membrane ,Endoplasmic reticulum ,Population ,Cell Biology ,Biology ,Golgi apparatus ,medicine.disease_cause ,Murray Valley encephalitis virus ,Virology ,Pathology and Forensic Medicine ,symbols.namesake ,Apoptosis ,Ultrastructure ,medicine ,symbols ,medicine.symptom ,education ,Molecular Biology - Abstract
We have examined the histological and ultrastructural features of CNS infection with Murray Valley encephalitis (MVE) virus in mice inoculated with a virulent parental strain (BH3479). Light microscopic examination revealed neuronal necrosis in the olfactory bulb and hippocampus of MVE-infected brains by 5 days post-infection (pi). Electron microscopy of these regions showed endoplasmic reticulum membrane proliferation, and tubular and spherical structures in the cisternae of the endoplasmic reticulum, Golgi complex and nuclear envelope. At seven to eight days pi, infected neurones exhibited chromatin condensation and extrusion, nuclear fragmentation, loss of segments of the nuclear envelope, reduced surface contact with adjacent cells and loss of cytoplasmic organelles. This cell injury was particularly noticeable in the proximal CA3 and distal CA1 regions of the hippocampus. The inflammatory cell profile consisted of macrophages, lymphocytes and especially neutrophils, and many of these inflammatory cells were apoptotic. High mortality rates in the BH3479-infected population of mice correlated with the intense polymorphonuclear and mononuclear leucocyte inflammatory infiltrate in the CNS.
- Published
- 2001
24. Retinal projections throughout optic nerve regeneration in the ornate dragon lizard,Ctenophorus ornatus
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John Papadimitriou, Sarah A. Dunlop, Lisa B.G. Tee, Ngan Tran, and Lyn Beazley
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biology ,Lizard ,General Neuroscience ,Optic disk ,Anatomy ,Commissure ,biology.organism_classification ,eye diseases ,Ctenophorus ornatus ,medicine.anatomical_structure ,nervous system ,Olfactory nerve ,biology.animal ,medicine ,Optic nerve ,sense organs ,Axon ,Tectum ,Neuroscience - Abstract
In goldfish and frog, optic nerve regeneration is successful, with restoration of retinotopic projections in visual brain centres and the return of functional vision within 1–2 months. By contrast, at 1 year after unilateral optic nerve crush in the ornate dragon lizard (Ctenophorus ornatus), the regenerated retinotectal projections lack topographic order, presumably explaining why the lizards are blind via the experimental eye (Beazley et al. [1997] J. Comp. Neurol. 377:105–120). To determine whether other abnormalities are associated with the inability to restore topographic projections in the lizard, we charted anatomically the time course, accuracy, and stability of optic nerve regeneration by examining visual projections with the lipophillic dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) applied to the optic disk at intervals up to 1 year after optic nerve crush; in addition, DiI tracing of small groups of axons was used to examine the topicity of axons projecting to the tectum. Axons re-innervated visual centres from between 1 and 2 months, a time frame comparable with that in goldfish and frog. However, the projections in lizard were found to differ from those in goldfish and frog in three major ways. First, there was considerable variability within the projection patterns both between individual lizards at any one stage and with time. Second, the projections were inaccurate. As in normal lizards, the major projection was to the contralateral optic tectum, although it lacked detectable retinotopic axon order throughout. Furthermore, misrouting occurred such that regenerating axons formed a persistent projection to the ipsilateral side of the brain that was considerably stronger and more widespread than normal. Minor visual centres also became re-innervated but, in addition, regenerating axons formed persistent projections into the opposite optic nerve and to non-retino-recipient regions such as the nucleus rotundus, hypothalamus, and olfactory nerve, as well as the posterior and tectal commissures. Third, the projections appeared unstable. Projections to both tecta were strongest between 3 and 5 months, but they diminished thereafter. The results suggest that, compared with goldfish and frog, in lizards both pathway and target cues are degraded and/or cannot be read adequately; as a consequence, regenerating axons are unable to navigate exclusively to visual centres and cannot re-form stable connections. J. Comp. Neurol. 415:188–200, 2000. © 2000 Wiley-Liss, Inc.
- Published
- 2000
25. Acute susceptibility of aged mice to infection with Candida albicans
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John Papadimitriou, Robert B. Ashman, and Alma Fulurija
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Microbiology (medical) ,Aging ,DNA, Complementary ,Necrosis ,Biology ,Kidney ,Polymerase Chain Reaction ,Microbiology ,Mice ,Immune system ,Immunity ,Candida albicans ,medicine ,Animals ,Interferon gamma ,Mycosis ,Myocardium ,Candidiasis ,Brain ,Heart ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,medicine.disease ,biology.organism_classification ,Myocarditis ,Immunology ,Mice, Inbred CBA ,Cytokines ,bacteria ,Female ,Tumor necrosis factor alpha ,Disease Susceptibility ,Systemic candidiasis ,medicine.symptom ,medicine.drug - Abstract
The effect of aging on host resistance to systemic candidosis was assessed by monitoring the course of infection in 16-month-old CBA/CaH mice (aged non-immune) and in a comparable group that had been infected with a sublethal dose of Candida albicans at 6 weeks of age (aged immune). Aged non-immune mice showed rapid progression of the disease, with a marked increase in the number of mycelia in the brain and kidney, and early morbidity. Foci of myocardial necrosis were evident, but inflammatory cells were sparse. The histological picture in the aged immune mice was similar to that in the aged non-immune group, although fewer mycelial aggregates were seen. Both groups of aged mice showed a significantly lower fungal burden in the brain on day 1 of infection, but on day 4, colony counts increased significantly in the aged non-immune mice. Comparison of cytokine gene expression in the infected brains showed that the relative amount of interferon-gamma and tumour necrosis factor-alpha cDNA were similar in all three groups. Interleukin-6 was elevated in both infected non-immune and uninfected aged mice. Aged immune mice showed no morbidity after challenge, and both colonisation and tissue damage were reduced in comparison with the aged non-immune animals.
- Published
- 1999
26. VITAMIN D RECEPTOR mRNA IS EXPRESSED IN OSTEOCLAST-LIKE CELLS OF HUMAN GIANT CELL TUMOR OF BONE (OSTEOCLASTOMA)
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David Wood, W.H. Huang, L.L. Daniels, Ulrich Seydel, John Papadimitriou, and Ming Zheng
- Subjects
musculoskeletal diseases ,medicine.medical_specialty ,Stromal cell ,medicine.diagnostic_test ,In situ hybridization ,Biology ,medicine.disease ,Calcitriol receptor ,Molecular biology ,Bone resorption ,Endocrinology ,medicine.anatomical_structure ,Osteoclast ,Giant cell ,Internal medicine ,medicine ,Orthopedics and Sports Medicine ,Giant-cell tumor of bone ,Fluorescence in situ hybridization - Abstract
The conventional view of the effects of 1,25- (OH)2D3on osteoclastogenesis and bone resorption are thought to be mediated by stromal cells or osteoblastic cell. Giant cell tumor of bone (GCT) is characterized by multinuclear giant cells (osteoclast-like cells) distributed among a mass of mononuclear cells. Because it is very difficult to obtain normal human osteoclasts, many investigators, including ourselves, have used GCT as a source of human osteoclasts to enhance the understanding of normal skeletal remodeling and especially the hormone regulation of osteoclast functions. In this report, expression of human vitamin D receptor (VDR) mRNA was examined in the various components of GCT using the fluorescence in situ hybridization (FISH) technique. The results showed that VDR gene transcripts were expressed in both multinuclear cells (osteoclast-like cells) and mononuclear macrophage-like cells but not in stromal-like tumor cells in two cases of GCT examined. Measurement of VDR gene transcripts in situ by confocal microscopy showed that the level of VDR mRNA in osteoclast-like giant cells is greater than that in macrophage-like cells (p < 0.05). These findings suggest that 1,25- (OH)2D3mediated osteoclastic bone resorption or osteoclastogenesis could at least, in part, occur by direct action on osteoclasts/their precursor cells.
- Published
- 1999
27. The repopulation of murine Langerhans cells after depletion by mild heat injury
- Author
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M. Ghaznawie, John Papadimitriou, and Peter J. Heenan
- Subjects
Pathology ,medicine.medical_specialty ,Langerhans cell ,Epidermis (botany) ,Ratón ,Regeneration (biology) ,Dermatology ,Biology ,Lesion ,medicine.anatomical_structure ,Dermis ,Precursor cell ,Immunology ,medicine ,Bone marrow ,medicine.symptom - Abstract
We have developed a model of focal Langerhans cell depletion by mild heat injury and used it to investigate the mechanisms of Langerhans cell repopulation in the injured epidermis. The possibility whether repopulation occurred by recruitment of precursor cells from the circulation or dermis or, alternatively, by migration from the surrounding normal epidermis into the injured area was considered. Repopulation was studied by evaluating the pattern of Langerhans cell reappearance and calculating the rate of change in the density. Heat injury followed by whole-body irradiation with shielding of the injured skin was used to assess repopulation in the absence of bone marrow precursors. Using tritiated thymidine autoradiography, we also investigated whether the newly arrived Langerhans cells (be they from circulating precursors or surrounding normal epidermis) actually divide. The results showed that heat injury completely eliminated the Langerhans cells within the area delineated by the injury. Two hours after injury, the Langerhans cells were fragmented and 2 days later, they could not be detected. Regeneration of the epidermis occurred 2 days after injury and Langerhans cells reappeared scattered somewhat sparsely in the centre of the lesion on day 3. These cells were small and slender, bearing one or two short dendrites. As the dendrites increased in number and in length, the cells became similar morphologically and phenotypically to normal Langerhans cells. The rate of repopulation increased dramatically between days 5 and 7 and reached normal density on day 11. The pattern of Langerhans cell repopulation in the injured area and the lack of repopulation in the irradiated animals indicated that repopulation occurs by immigration of precursors from the circulation or dermis. There was no indication of migration of Langerhans cells from surrounding normal epidermis. Lastly, the newly arrived Langerhans cells failed to divide at the site of injury.
- Published
- 1999
28. Both CD4+ and CD8+ lymphocytes reduce the severity of tissue lesions in murine systemic candidiasis, and CD4+ cells also demonstrate strain-specific immunopathological effects
- Author
-
Robert B. Ashman, Alma Fulurija, and John Papadimitriou
- Subjects
CD4-Positive T-Lymphocytes ,Adoptive cell transfer ,medicine.medical_treatment ,Lymphocyte ,Spleen ,Inflammation ,CD8-Positive T-Lymphocytes ,Biology ,Kidney ,Microbiology ,Lymphocyte Depletion ,Mice ,Immune system ,Species Specificity ,Candida albicans ,medicine ,Animals ,Mice, Inbred BALB C ,Candidiasis ,Brain ,T lymphocyte ,medicine.disease ,Adoptive Transfer ,medicine.anatomical_structure ,Cytokine ,Immunology ,Mice, Inbred CBA ,Cytokines ,Female ,Systemic candidiasis ,medicine.symptom - Abstract
The role of T lymphocytes in host responses to sublethal systemic infection with Candida albicans was evaluated by mAb depletion of CD4+ and CD8+ cells from BALB/c and CBA/CaH mice, which develop mild and severe tissue damage, respectively. Depletion of CD4+ lymphocytes from BALB/c mice markedly increased tissue damage, but did not alter the course of infection. In CBA/CaH mice, depletion of CD4+ cells abrogated tissue destruction in both brain and kidney at day 4 after infection, and significantly decreased fungal colonization in the brain. However, the severity of tissue lesions increased relative to controls from day 8 onwards. A small increase in tissue damage was evident in both mouse strains after depletion of CD8+ cells. There were no major differences between days 4 and 8 after infection in cDNA cytokine profiles of CD4+ lymphocytes from either BALB/c or CBA/CaH mice. After passive transfer into infected syngeneic recipients, spleen cells from infected CBA/CaH mice markedly increased tissue damage when compared to controls, and also caused a significant increase in fungal colonization in the brain. A similar transfer in BALB/c mice increased the number of inflammatory cells in and around the lesions, but had no effect on the fungal burden in brain and kidney. The data demonstrate that both CD4+ and CD8+ lymphocytes contribute to the reduction of tissue damage after systemic infection with C. albicans, and that the development and expression of CD4+ lymphocyte effector function is influenced by the genetic background of the mouse.
- Published
- 1999
29. [Untitled]
- Author
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Jennet Harvey, Larry Witte, Michael J. Edel, Daniel J. Hicklin, and John Papadimitriou
- Subjects
Cancer Research ,Pathology ,medicine.medical_specialty ,Axillary lymph nodes ,biology ,Physiology ,Angiogenesis ,Clinical Biochemistry ,Mammary gland ,medicine.disease ,Receptor tyrosine kinase ,Metastasis ,medicine.anatomical_structure ,cardiovascular system ,medicine ,biology.protein ,Immunohistochemistry ,Breast carcinoma ,Lymph node - Abstract
Although it is generally accepted that tumour growth is angiogenesis dependent, little is known about the role of angiogenesis in the metastatic process. Recent evidence suggests that the angiogenic tyrosine kinase receptor KDR is pivotal in new vessel formation. To investigate, therefore, the association between new vessel formation in primary breast carcinoma and axillary lymph node metastasis we have used computer assisted video analysis to assess the vascular distribution as well as the level of expression of KDR in individual vessels in sections of invasive breast carcinomas, some of which had metastasized to the axillary lymph nodes and some that had not. We specifically assessed the frequency distribution, perimeter, area, and density of KDR positive vessels in the same sections of tumours. Our results show that in invasive mammary carcinoma KDR is expressed exclusively on the surface and cytoplasm of endothelial cells of approximately 71% of vessels, but the level of expression in individual vessels does not correlate with the presence of axillary lymph node metastases (P > 0.10). However, we found that small vessels express higher levels of KDR (P < 0.02) than larger vessels and that there is a significantly higher frequency of relatively small (< 90 μm in perimeter) KDR positive vessels in breast tumours that had metastasized to the axillary lymph nodes than those that had not (P < 0.001). In conclusion, increased density and frequency of KDR positive small vessels in primary invasive breast carcinoma correlates with axillary lymph node metastases.
- Published
- 1999
30. A secondCandida albicansresistance gene (Carg2) regulates tissue damage, but not fungal clearance, in sub-lethal murine systemic infection
- Author
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Alma Fulurija, Robert B. Ashman, and John Papadimitriou
- Subjects
Ratón ,Genes, Fungal ,Sensitivity and Specificity ,Microbiology ,Pathogenesis ,Mice ,Candida albicans ,medicine ,Animals ,Allele ,Gene ,Alleles ,Brain Diseases ,Kidney ,integumentary system ,biology ,Candidiasis ,Fungi imperfecti ,biology.organism_classification ,Yeast ,Mice, Inbred C57BL ,Infectious Diseases ,medicine.anatomical_structure ,Immunology ,Kidney Diseases - Abstract
The severity of systemic infection with the yeast Candida albicans has been shown to be under complex genetic control. C57/L mice carry an allele that is associated with an increase in tissue destruction when compared with C57BI/6 mice; however, the gene affects only the severity of tissue lesions, and does not influence the magnitude of the fungal burden in either kidney or brain. Studies in [C57/L x C57BI/6]F1 hybrid mice, and [C57/L x C57BI/6]F1 x C57/L backcross mice, demonstrated that the gene behaves as a simple Mendelian co-dominant. (C) 1998 Academic Press.
- Published
- 1998
31. Factors influencing the effects of murine cytomegalovirus on the pancreas
- Author
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John Papadimitriou, Alan G. Baxter, R.N. Allcock, and Patricia Price
- Subjects
Human cytomegalovirus ,medicine.medical_treatment ,Clinical Biochemistry ,Congenic ,General Medicine ,Nod ,Biology ,medicine.disease ,Biochemistry ,Natural killer cell ,medicine.anatomical_structure ,Cytokine ,Immunology ,medicine ,Pancreatitis ,Insulitis ,NOD mice - Abstract
BACKGROUND: As human cytomegalovirus (HCMV) infections are implicated in insulin-dependent diabetes mellitus (IDDM), the effects of murine (M)CMV infection of inbred mice on the pancreas are of interest. RESULTS: Inflammation and periacinar oedema peaked on day 3 and were replaced by a focal inflammation, but infected cells were rare. The islets were spared in C57BL mice. Insulitis normally seen in non-obese diabetic (NOD) mice was accelerated, but infected NOD mice did not become glycosuric. Isotypes of total and autoreactive antibodies suggested a shift to a Th 1 response (IgG2a) in all MCMV-infected mice. MCMV-induced pancreatitis was not affected by MHC genes but was similar or less severe in BALB/c mice. As these lack the Cmv1 gene, which provides a protective natural killer (NK) cell response in C57BL congenic mice, the C57BL background may carry a pancreatitis susceptibility gene able to counter NK-mediated restriction of viral replication. Consistently, congenic mice expressing Cmvl on a BALB/c background did not display pancreatitis, unless depleted of NK cells. In vivo treatment with soluble cytokine receptors suggested that interleukin 1 (IL-1) and/or tumour necrosis factor alpha contribute to acinar necrosis in C57BL mice.
- Published
- 1998
32. Gene expression of monocyte chemoattractant protein-1 in giant cell tumors of bone osteoclastoma: Possible involvement in CD68+ macrophage-like cell migration
- Author
-
John Papadimitriou, Ying Fan, S. Wysocki, David Wood, Minghao Zheng, and Anne Smith
- Subjects
CD68 ,Cell Biology ,In situ hybridization ,Biology ,medicine.disease ,Biochemistry ,Peripheral blood mononuclear cell ,Molecular biology ,Giant cell ,medicine ,Macrophage ,Giant Cell Tumors ,Northern blot ,Molecular Biology ,Giant-cell tumor of bone - Abstract
Giant cell tumor of bone (GCT) is one of a few neoplasms in which the macrophage/osteoclast precursor cells and osteoclast-like giant cells infiltrate the tumor mass. Monocyte chemoattractant protein 1 (MCP-1) is a potent chemotactic factor specific for monocytes. In search of relevant cytokines that may enhance the recruitment of these reactive cells, we evaluated the localization and regulation of MCP-1 mRNA and protein in GCT by using Northern blot analysis, in situ hybridization and immunohistochemistry. We also determined whether conditioned medium obtained from GCT cultures can recruit human peripheral blood monocytes (CD68+) in an in vitro chemotactic assay. Using Northern blot analysis, we detected the specific gene transcript for MCP-1 in all GCT samples tested. In situ hybridization and immunohistochemistry revealed that both MCP-1 gene transcript and protein were consistently present in the cytoplasm of stromal-like tumor cells of GCT. Treatment of mononuclear cells from GCT at third passage with TGF-β1 for 24 h increased the level of MCP-1 mRNA in a dose-dependent manner, with the maximum effect at 1 ng/ml. Conditioned media from GCT cultures promoted the chemotactic migration of CD68+ peripheral monocytes, an activity which was abolished by the addition of MCP-1 antibody to the conditioned medium. Thus, the results of this study suggest that recruitment of CD68+ macrophage-like cells may be due to the production MCP-1 by stromal-like tumor cells. These CD68+ cells may originate from peripheral blood and could have the capability of further differentiating into osteoclasts in the tumor. J. Cell. Biochem. 70:121–129, 1998. © 1998 Wiley-Liss, Inc.
- Published
- 1998
33. Pax7 includes two polymorphic homeoboxes which contain rearrangements associated with differences in the ability to regenerate damaged skeletal muscle in adult mice
- Author
-
Sue Fletcher, John Papadimitriou, Melanie Ziman, Donna Harmon, Terry Robertson, and Peter Kay
- Subjects
TaqI ,Molecular Sequence Data ,Muscle Proteins ,Nerve Tissue Proteins ,Biology ,Biochemistry ,DNA sequencing ,Mice ,chemistry.chemical_compound ,medicine ,Animals ,Regeneration ,Allele ,Deoxyribonucleases, Type II Site-Specific ,Muscle, Skeletal ,Alleles ,Southern blot ,Homeodomain Proteins ,Genetics ,Mice, Inbred BALB C ,Base Sequence ,Myogenesis ,Genes, Homeobox ,Nucleic Acid Hybridization ,PAX7 Transcription Factor ,Skeletal muscle ,DNA ,Cell Biology ,musculoskeletal system ,Molecular biology ,Peptide Fragments ,Blotting, Southern ,medicine.anatomical_structure ,chemistry ,Homeobox ,PAX7 ,tissues ,Polymorphism, Restriction Fragment Length - Abstract
Pax7 is a paired-type homeobox gene which has previously been shown to play an important role in skeletal muscle formation. It is expressed in skeletal muscle of the limbs during embryogenesis and in adulthood. The aims of this study were firstly to determine the degree of polymorphism of Pax7 amongst inbred laboratory mice using Southern blotting and Pax7 regional specific sub-probes. Secondly, functional studies were performed on mice with each of the different structural forms of Pax7 to determine whether they were associated with differences in the ability to regenerate damaged skeletal muscle. Four different allelic forms of Pax7 have now been identified in laboratory mice indicating that the previously reported DNA sequence of Pax7 is not applicable to all laboratory mice. Hybridisation patterns of TaqI digested DNA representing each of the different Pax7 alleles with the Pax7 specific sub-probes suggested that in contrast to previous findings, Pax7 is associated with two highly polymorphic homeoboxes. The presence of two homeoboxes in BALB/c mice has been confirmed by DNA sequencing. Results of functional studies have also shown that the ability to regenerate damaged skeletal muscle in adult mice is strongly associated with the presence of a 0.15-kb TaqI fragment derived from one of the homeoboxes.
- Published
- 1998
34. The pathobiology of peritonitis
- Author
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John C. Hall, Kathryn A. Heel, Cameron Platell, and John Papadimitriou
- Subjects
Innate immune system ,Hepatology ,Lipopolysaccharide ,business.industry ,Peritoneal fluid ,Gastroenterology ,Peritonitis ,medicine.disease ,Cell biology ,Microscopy, Electron ,chemistry.chemical_compound ,medicine.anatomical_structure ,Immune system ,Peritoneum ,chemistry ,Immunology ,medicine ,Humans ,Interferon gamma ,business ,Mesothelial Cell ,medicine.drug - Abstract
The peritoneum is more than a mechanical covering that allows for the easy gliding of opposed peritoneal surfaces. The peritoneal mesothelial cells facilitate the action of powerful innate immune mechanisms. In addition, the peritoneal-associated lymphoid tissues contain unique cells that may play a crucial role in the localization of intraperitoneal infection. A clearer understanding of the molecular and cellular events underlying peritoneal functions in both the unstimulated and stimulated state will aid future treatment of peritonitis.
- Published
- 1998
35. A Novel MspI PCR-RFLP in the Human Cytosine 5-Methyltransferase Gene: Lack of Relevance for Malignant Lymphoproliferative Disease and Breast Cancer
- Author
-
Mohammed O. Ahmed, Aparna N. Bagwe, John Papadimitriou, Peter Kay, M. Franchina, and Dominic V. Spagnolo
- Subjects
Genetics ,Biology ,Molecular biology ,Gene dosage ,law.invention ,genomic DNA ,chemistry.chemical_compound ,chemistry ,law ,Copy-number variation ,Restriction fragment length polymorphism ,Gene ,Genotyping ,Genetics (clinical) ,Polymerase chain reaction ,Cytosine - Abstract
Two alternate allelic forms of human cytosine 5-methyltransferase, 5-MT I and 5-MT II, which differ by the absence or presence of an intronic MspI recognition sequence, have been recognised. The polymorphic region was localised using a series of subprobes prepared upon MspI digestion of the 2.5-kb cDNA probe (hmt-2.5). A PCR-based method was then developed for rapid 5-MT genotyping. The gene and phenotype frequencies of 5-MT I and 5-MT II were not significantly different in genomic DNA samples from a series of non-Hodgkin’s lymphomas and breast cancer cases compared with DNA from normal subjects. Allelism of 5-MT allows new approaches to the assessment of variation in gene copy number of 5-MT in different types of neoplasia.
- Published
- 1998
36. [Untitled]
- Author
-
John Papadimitriou, Ulrich Seydel, David Wood, Ming Zheng, Geoffrey C. Nicholson, and S. Yovich
- Subjects
musculoskeletal diseases ,Pathology ,medicine.medical_specialty ,biology ,Chemistry ,Demineralized bone matrix ,Osteoid ,Cell Biology ,Bone healing ,Bone resorption ,Cell biology ,Resorption ,medicine.anatomical_structure ,Osteoclast ,Bone cell ,medicine ,biology.protein ,Osteopontin ,Anatomy - Abstract
Osteoclasts resorb bone by a complex dynamic process that initially involves attachment, polarization and enzyme secretion, followed by their detachment and migration to new sites. In this study, we postulated that mineralized and osteoid bone matrix signal osteoclasts differently, resulting in the resorption of mineralized bone matrix only. We, therefore, compared the cytoplasmic distribution of cytoskeletal proteins F-actin and vinculin using confocal laser-scanning microscopy in osteoclasts cultured on mineralized and demineralized bone slices and correlated the observations with their functional activity. Our results have demonstrated significant differences in F-actin and vinculin staining patterns between osteoclasts cultured on mineralized bone matrix and those on demineralized bone matrix. In addition, the structural variations were accompanied by significant differences in bone resorbing activity between osteoclasts grown on mineralized bone matrix and those on demineralized bone matrix after 24 h of culture --resorption only occurring in mineralized bone but not in demineralized bone. These results indicated that failure of osteoid bone resorption is caused by perturbation of osteoclast polarization.
- Published
- 1998
37. Assessment of vascularity in breast carcinoma by computer-assisted video analysis (CAVA) and its association with axillary lymph node status
- Author
-
Jennet Harvey, John Papadimitriou, Peter Robbins, Michael J. Edel, H.J.S. Dawkins, M.F. D'Antuono, and C.A. Mitchel
- Subjects
Cancer Research ,medicine.medical_specialty ,Pathology ,Breast Neoplasms ,Metastasis ,Vascularity ,Breast cancer ,medicine ,Carcinoma ,Humans ,Lymph node ,Microscopy ,Computers ,business.industry ,Middle Aged ,medicine.disease ,medicine.anatomical_structure ,Oncology ,Case-Control Studies ,Lymphatic Metastasis ,Axilla ,Female ,Histopathology ,Radiology ,medicine.symptom ,Breast carcinoma ,business ,Blood vessel - Abstract
Case-control methodology was used to evaluate the significance of vascularity in small breast carcinomas with regard to the presence or absence of axillary lymph node metastases. Vascularity was assessed in 32 axillary node positive primary breast tumours (LN+ve) less than 2 cm in size and compared with 56 control axillary node negative primary tumours (LN-ve), which were matched for histological type and grade and tumour size. This study design employed computer-assisted video analysis (CAVA) to assess the total blood vessel perimeter (BVP), total blood vessel area (BVA), and total blood vessel density (BVD) throughout a tissue section that encompassed an entire cross section of the tumour and its immediate periphery. The BVA and BVD in these tumours were not significantly different between LN+ve and LN-ve groups. The LN-ve carcinomas had, on average, a significantly (P0.05) higher total BVP (3355 microm/mm2) than LN+ve tumours (2771 microm/mm2). 'Hot spot' areas were also independently assessed by two pathologists and the same areas measured by CAVA. A strong correlation (P0.001) between the two methods of assessment of BVD of the neovascular 'hot spots' was found; however, no association with axillary lymph node metastasis was found using either method of assessment. In conclusion, vascularity assessed by either blood vessel density or blood vessel size in primary invasive breast cancers less than 2 cm in diameter showed no association with axillary lymph node metastasis; in fact a negative association was found with total BVP of whole tumour sections and BVD in 'hot spots' using CAVA. Further, this study has established a computer-assisted method of quantifying vascularity in solid neoplasms and is a positive step towards a standardised approach to this diverse and methodologically variable area.
- Published
- 1998
38. Analysis of haemorrhagic septicaemia-causing isolates of Pasteurella multocida by ribotyping and field alternation gel electrophoresis (FAGE)
- Author
-
Hugh Dawkins, K. M. Townsend, and John Papadimitriou
- Subjects
DNA, Bacterial ,Electrophoresis ,Serotype ,Pasteurella multocida ,Buffaloes ,Pasteurella Infections ,Cattle Diseases ,Hemorrhagic septicemia ,Microbiology ,Ribotyping ,otorhinolaryngologic diseases ,medicine ,Animals ,Humans ,Typing ,Serotyping ,Deoxyribonucleases, Type II Site-Specific ,Hemorrhagic Septicemia ,Bison ,General Veterinary ,biology ,Molecular epidemiology ,Deer ,Reproducibility of Results ,General Medicine ,biology.organism_classification ,medicine.disease ,Virology ,Genetic Techniques ,Cattle ,Restriction fragment length polymorphism ,Pasteurellosis ,Polymorphism, Restriction Fragment Length - Abstract
Ribotyping and field alternation gel electrophoresis (FAGE) were used to examine 19 Pasteurella multocida isolates, and to assess the ability of these techniques to differentiate P. multocida strains that cause haemorrhagic septicaemia (HS). Reproducible patterns were obtained from both methods, with FAGE demonstrating greater discriminatory power than ribotyping. FAGE analysis was particularly useful in distinguishing North American cultures originating from the 1922 Yellowstone National Park Buffalo 'B' strain, demonstrating the ability to detect genetic alterations induced by repeated subculture. A remarkable homogeneity was observed among Asian HS strains following ribotyping and FAGE analysis, with a clear distinction observed between virulent and avirulent HS isolates. This study has illustrated the value of genomic fingerprinting methods in distinguishing strains of similar serotype, and the capability of these methods to produce detailed characterisation of P. multocida isolates.
- Published
- 1997
39. REP-PCR analysis of Pasteurella multocida isolates that cause haemorrhagic septicaemia
- Author
-
John Papadimitriou, Hugh Dawkins, and K.M. Townsend
- Subjects
DNA, Bacterial ,Serotype ,Turkeys ,Pasteurella multocida ,Buffaloes ,Swine ,DNA Fragmentation ,Polymerase Chain Reaction ,Microbiology ,Bacterial genetics ,Birds ,chemistry.chemical_compound ,otorhinolaryngologic diseases ,Consensus sequence ,Animals ,Humans ,Hemorrhagic Septicemia ,Poultry Diseases ,Swine Diseases ,Base Sequence ,Bison ,General Veterinary ,biology ,Bird Diseases ,Deer ,biology.organism_classification ,DNA Fingerprinting ,Virology ,genomic DNA ,chemistry ,DNA fragmentation ,Cattle ,Fowl cholera ,DNA - Abstract
Amplification of multiple P multocida genomic DNA fragments by outwardly-directed primers based on the repetitive extragenic palindromic (REP) consensus sequence, generated complex profiles in a PCR-based fingerprinting method known as REP-PCR. Polymorphisms within REP-PCR profiles were used to characterise 38 isolates of P multocida. The high degree of homogeneity observed among haemorrhagic septicaemia (HS) strains of serotype B and E provided evidence of a disease-associated REP profile that may serve as a novel method for the identification of HS strains regardless of serotype. REP-PCR profiles of other P multocida serotypes were highly variable, illustrating the potential of this technique for the molecular fingerprinting of fowl cholera or atrophic rhinitis isolates. A specific amplified REP fragment was isolated and used to probe membrane-bound digested P multocida genomic DNA. Hybridisation patterns not only distinguished HS-causing isolates from non-HS P multocida, but also demonstrated a degree of relatedness between HS and HS-like strains.
- Published
- 1997
40. Age-related congophilic inclusions in the brains of apolipoprotein E-deficient mice
- Author
-
A.D Roses, Nichole Dutton, Ralph N. Martins, Terry Robertson, John Papadimitriou, and Byron Kakulas
- Subjects
Male ,Apolipoprotein E ,Aging ,Apolipoprotein B ,Hippocampal formation ,Mice ,Mice, Neurologic Mutants ,Apolipoproteins E ,medicine ,Animals ,Coloring Agents ,Amyloid beta-Peptides ,biology ,General Neuroscience ,Antibodies, Monoclonal ,Brain ,Congo Red ,Immunohistochemistry ,Molecular biology ,Mice, Inbred C57BL ,Protoplasm ,Microscopy, Electron ,medicine.anatomical_structure ,Biochemistry ,Cytoplasm ,Nerve Degeneration ,biology.protein ,Neuroglia ,Female ,Immunostaining ,Astrocyte - Abstract
The hippocampal region of apolipoprotein E-deficient mice of varying ages was examined for any morphological changes by light and electron microscopy. Unusual periodic acid-Schiff-positive granules were seen in the hippocampal area of these animals as early as the fourth week of life and their numbers increased gradually with age. These granules were never found in control C57BL/6J (B6) mice before six months-of-age and their numbers were invariable low. They were strongly congophilic when stained with a modified Congo Red technique and reacted with a monoclonal antibody specific to amino acids 17-24 and 35-43 of the beta-amyloid peptide. The immunostaining of these granules with the beta-amyloid peptide was lost after specific adsorption with the appropriate synthetic peptide. These granules were identified ultrastructurally as non-membrane-bound fibrillogranular material in the cytoplasm of protoplasmic astrocytes. The data indicate that an amyloid-like protein accumulates in the protoplasmic astrocytes of the hippocampus of apolipoprotein E-deficient mice, especially in the brains of old animals.
- Published
- 1997
41. Evidence that two independent host genes influence the severity of tissue damage and susceptibility to acute pyelonephritis in murine systemic candidiasis
- Author
-
Robert B. Ashman, Alma Fulurija, and John Papadimitriou
- Subjects
Ratón ,Kidney ,Hemolysis ,Microbiology ,Pathogenesis ,Mice ,Mice, Inbred AKR ,Inbred strain ,medicine ,Animals ,Genetic Predisposition to Disease ,Candida albicans ,Alleles ,Mycosis ,biology ,Candidiasis ,Brain ,Complement System Proteins ,biology.organism_classification ,medicine.disease ,Null allele ,Mice, Mutant Strains ,Mice, Inbred C57BL ,Infectious Diseases ,medicine.anatomical_structure ,Immunology ,Female ,Systemic candidiasis - Abstract
Tissue damage in the kidney and brain after systemic infection with Candida albicans was examined in recombinant inbred strains (AKXL) derived from AKR and C57/L progenitors. Nine of the 15 strains showed mild (C57/L-like) tissue damage. Of the remainder, two strains developed lesions comparable to the AKR parental strain, whereas four exhibited a much move severe pattern of tissue damage. This was characterized by pronounced mycelial growth in the brain, and gross oedema of the kidney, with extensive fungal colonization and marked tissue destruction. The presence of the null allele of the haemolytic complement gene (Hc) may be necessary but not sufficient, for the expression of the very severe lesions. The results were interpreted as reflecting the actions of two independent genes, which have been designated Carg1 and Carg2 (Candida albicans resistance genes 1 and 2). (C) 1997 Academic Press Limited.
- Published
- 1997
42. Anterior, posterior, or laparoscopic approach for the management of adrenal diseases?
- Author
-
Dimitrios Linos, Athanasios Souvatzoglou, Michails Boukis, Nikolaos Stylopoulos, Sotirios A. Raptis, and John Papadimitriou
- Subjects
Adult ,Male ,Laparoscopic surgery ,medicine.medical_specialty ,Time Factors ,Adolescent ,medicine.medical_treatment ,Adrenal Gland Diseases ,Adrenal Gland Neoplasms ,Statistics, Nonparametric ,Germany ,medicine ,Humans ,Anterior posterior ,Intraoperative Complications ,Laparoscopy ,Aged ,Analysis of Variance ,Pain, Postoperative ,Chi-Square Distribution ,medicine.diagnostic_test ,Patient-controlled analgesia ,business.industry ,Adrenalectomy ,Health Care Costs ,General Medicine ,Length of Stay ,Middle Aged ,Surgery ,medicine.anatomical_structure ,Concomitant ,Abdomen ,Female ,business ,Chi-squared distribution ,Follow-Up Studies - Abstract
Background At the advent of laparoscopic adrenalectomy it seemed timely to us to assess the advantages and the overall results of the different techniques that are currently used in an approach to adrenalectomy. Patients and methods Between 1984 and 1995, 165 patients underwent adrenalectomy. Eightysix patients (37 men and 49 women with a mean age of 46.4 years) underwent adrenalectomy via the anterior approach, 61 patients (18 men and 43 women with a mean age of 43.8 years) underwent posterior extraperitoneal adrenalectomy, and 18 patients (8 men and 10 women with a mean age of 48.7 years) underwent anterior laparoscopic adrenalectomy. For statistical analysis of the different comparisons between the groups we used the t test for independent samples, the Wilcoxon test, chi-square, and one way analysis of variance. Results There was no operative mortality. The morbidity was 13.9% in the anterior approach, 9.8% in the posterior approach, and 0% in the laparoscopic approach. The mean operating time for unilateral adrenalectomy was 155.3 min (range 75 to 315) for the anterior approach, 108.6 min (range 60 to 195) for the posterior approach and 116.1 min (range 75 to 180) for the laparoscopic approach. For bilateral adrenalectomy the mean operating time was 165 min for the anterior and 178 min for the posterior approach. The average diameter of tumors resected anteriorly was 8.07 cm (range 2.5 to 20), posteriorly was 5.25 cm (range 0.5 to 14), and laparoscopically was 4.03 cm (range 2 to 6.5). The mean length of postoperative hospitalization for patients undergoing unilateral adrenalectomy was 8 days (range 2 to 25) for the anterior approach, 4.5 days (range 1 to 11) for the posterior approach, and 2.2 days (range 1 to 5) for the laparoscopic approach. Patient controlled analgesia lasted 3.4 days for those operated anteriorly, 2.3 days for those operated posteriorly, and 1.08 days for those that underwent laparoscopic adrenalectomy. Conclusions The laparoscopic approach to the adrenal promises the safest and least painful operation with shorter in-hospital stay and the best cosmetic and long-term results. The posterior approach is the fastest of all and a better overall operation than the anterior approach that should only be reserved for removing very large adrenal tumors and when concomitant intra-abdominal procedures, that can't be handled laparoscopically, are anticipated.
- Published
- 1997
43. Microsatellite instability and loss of heterozygosity in mammary carcinoma and its probable precursors
- Author
-
Gavin R. Turbett, W.B. De Boer, John Papadimitriou, and E.K. Dillon
- Subjects
Genetic Markers ,Cancer Research ,Heterozygote ,Mammary gland ,Breast Neoplasms ,Biology ,medicine.disease_cause ,Malignancy ,Epithelium ,Loss of heterozygosity ,medicine ,Carcinoma ,Humans ,Breast ,Hyperplasia ,Microsatellite instability ,DNA, Neoplasm ,medicine.disease ,medicine.anatomical_structure ,Oncology ,Cancer research ,Microsatellite ,DNA mismatch repair ,Female ,Lymph Nodes ,Chromosome Deletion ,Carcinogenesis ,Carcinoma in Situ ,Research Article ,Microsatellite Repeats - Abstract
Microsatellite instability is a form of genetic damage that may be due to defective mismatch repair genes and may be a marker of processes leading to malignancy. We have analysed a series of epithelial hyperplasia of usual type, carcinomas in situ and invasive and metastatic carcinomas from the mammary gland on the assumption that they represent stages in the evolution of mammary carcinoma. Eight markers on chromosomes 3p, 4q, 9p, 11p, 14q, 17p, 17q and Xq were examined for microsatellite instability and loss of heterozygosity. High rates of loss on chromosomes 17p, 17q and Xq indicate that these chromosomal arms contain genes important in mammary carcinogenesis. The rate of microsatellite instability observed in this study was uniformly low, irrespective of the lesion. This implies that microsatellite instability is not a marker of malignancy in most instances of mammary neoplasia. Images Figure 1 Figure 2 Figure 3
- Published
- 1997
44. The Practice of Electroconvulsive Therapy in Greece
- Author
-
Kaliora, Styliani C. Braga, Raphael J. Petrides, Georgios and Chatzimanolis, John Papadimitriou, George N. Zervas, Iannis M.
- Subjects
mental disorders ,behavioral disciplines and activities - Abstract
Objective: To describe the practice of electroconvulsive therapy (ECT) in Greece. Methods: A survey was conducted during the academic year 2008-2009. Electroconvulsive therapy use was investigated for 2007. All civilian institutions providing inpatient care were included. Centers that provided ECT completed a 57-item questionnaire. Centers that did not offer ECT completed a 13-item questionnaire. Results: Fifty-five (82.1%) of 67 institutions responded. Electroconvulsive therapy was offered in 18 hospitals. Only 2 of 10 university hospitals offered ECT. Overall, 137 patients were treated with 1271 sessions in 2007. Only 1.47% discontinued treatment owing to adverse events. There were no deaths. Schizophrenia was the most common diagnosis (41.3%) among those receiving ECT, followed by major depression (28.9%), bipolar depression (9.1%), catatonia (4.1%), suicidal ideation (3.3%), and schizoaffective disorder (2.5%). Physicians considered major depression (93.8%), catatonia (86.5%), schizophrenia (56.3%), and mania (50%) the most appropriate indications. Written informed consent was required in 77.8% of the institutions, whereas the rest required verbal consent. Bilateral ECT was the preferred electrode placement (88.9%). Modified ECT was used exclusively. Propofol was the preferred anesthetic (44.4%), followed by thiopental (38.9%). Seven (38.9%) of 18 hospitals used a fixed stimulus dose at first treatment. Five (27.8%) of 18 hospitals used the half-age method. Continuation/maintenance ECT was used in 33.3% of the hospitals. Outpatient ECT was seldom used. Lack of training, difficult access to anesthesiology, billing issues, and stigma were cited as the main impediments to the practice of ECT. Conclusions: Electroconvulsive therapy is practiced in moderate numbers in Greece and almost exclusively on an inpatient basis. Lack of training and lack of availability of anesthesiologists were cited as the most common obstacles to providing ECT.
- Published
- 2013
45. Detection of a population of long-lived cells in mammary epithelium of the mouse
- Author
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Hugh Dawkins, Nikolajs Zeps, M.-N. I. Walters, Sharon L. Redmond, and John Papadimitriou
- Subjects
Pathology ,medicine.medical_specialty ,Histology ,Population ,Cell ,Biology ,Tritium ,Pathology and Forensic Medicine ,Mice ,chemistry.chemical_compound ,Mammary Glands, Animal ,Estrus ,medicine ,Animals ,education ,Epithelial cell differentiation ,Estrous cycle ,Mice, Inbred BALB C ,education.field_of_study ,Cell Differentiation ,Epithelial Cells ,Cell Biology ,Molecular medicine ,Cell biology ,medicine.anatomical_structure ,Mammary Epithelium ,chemistry ,Female ,Stem cell ,Thymidine - Abstract
The fate of dividing mouse mammary epithelial cells was followed by use of tritiated thymidine (3H-Tdr) autoradiography. Loss of label consistent with halving kinetics was observed at various times after injection; however, heavily labelled cells were frequently observed at two weeks and later, when none was expected. The grain count over these heavily labelled cells was often comparable with that 1 h after 3H-Tdr injection. Extensive serial sectioning revealed that the heavily labelled cells were often single cells surrounded by many unlabelled cells or that their label was in stark contrast (in excess of 20 reduced silver grains) to the surrounding group of cells whose label was just above background (a maximum of 3 grains). In addition, by injecting mice at different stages of oestrus, we demonstrated that these long-lived cells, although influenced by oestrus, replicated independently of the oestrogen peak. Our data support a model for mouse mammary epithelium that has a single 'stem' cell positioned within a group of its progeny to form a discrete proliferative unit. This model requires many such stem cells within the mammary epithelium and is consistent with similar models proposed for other tissues.
- Published
- 1996
46. CHANGES IN THE CONCENTRATION OF MICROVILLI ON THE FREE SURFACE OF HEALING MESOTHELIUM ARE ASSOCIATED WITH ALTERATIONS IN SURFACE MEMBRANE CHARGE
- Author
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Steven E. Mutsaers, Darrel Whitaker, and John Papadimitriou
- Subjects
Pathology ,medicine.medical_specialty ,biology ,Chemistry ,Pathology and Forensic Medicine ,law.invention ,Glycosaminoglycan ,Glycocalyx ,Mesothelium ,Membrane ,medicine.anatomical_structure ,Concanavalin A ,law ,biology.protein ,medicine ,Biophysics ,Surface charge ,Electron microscope ,Mesothelial Cell - Abstract
The luminal plasmalemma of regenerating mesothelial cells was examined by transmission electron microscopy and the concentration of microvilli at various stages of healing was quantified. Charged tracer and lectin binding techniques were also employed to investigate electrostatic and chemical changes in mesothelial glycocalyx. In uninjured mesothelium and at all stages of healing, the concentration of microvilli at the cellular periphery was greater than over the main cell mass (P < 0.05). Furthermore, there was an increase in the concentration of microvilli in all regions by day 4, which reached a maximum at day 6, then at days 10-15 returned to values closer to uninjured mesothelium (P < 0.01). These changes were associated with an alteration in surface charge. In all lesions, the surface charge on microvillar membranes was greater than for flat membranes, but the difference was only significant at days 4, 6, and 15 (P < 0.001). The changes in surface charge may reflect a differential expression of mucopolysaccharides on the surface membrane. In addition, concanavalin A bound avidly to mesothelial surface membranes, suggesting the presence of alpha-methyl-D-mannoside residues. These findings suggest an association between microvillar formation and surface charge, the former protecting the healing mesothelium by enhancing entrapment of serosal fluid and its contents.
- Published
- 1996
47. Short Communication: Initiation of impaired outer segment degradationin vivousing an antisense oligonucleotide
- Author
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Laurence Rapp, May C. Lai, Sarojini Vijayasekaran, Ian J. Constable, Piroska E. Rakoczy, John Papadimitriou, and Terry Robertson
- Subjects
Retina ,Oligonucleotide ,medicine.medical_treatment ,Biology ,Molecular biology ,Photoreceptor outer segment ,Sensory Systems ,In vitro ,Cellular and Molecular Neuroscience ,Ophthalmology ,medicine.anatomical_structure ,In vivo ,Sense (molecular biology) ,Antisense oligonucleotides ,medicine ,sense organs ,Saline - Abstract
This paper describes the first successful in vivo application of antisense DNA technology to induce the accumulation of photoreceptor outer segment derived debris in the retina. An antisense oligonucleotide (CatSC), which was previously demonstrated to be an effective tool to induce debris accumulation in vitro, was injected into the vitreous of pigmented and non-pigmented rats. The animals were euthanased 7 days after the injections. The number of inclusions significantly increased in the RPE layer of Long Evans and RCS-rdy + rats injected with 66 ug of CatSC to 96.13 ↣ 2.6 (SD) (p < 0.0003) and 204.2 ↣ 39.3 (SD) (p < 0.0001), respectively. The difference between the number of phagosome-like inclusions present in control saline, 6.6 ug of CatSC or 66 ug of sense oligonucleotide (S1) injected animals was not statistically significant. There were no abnormalities observed in the inner layers of the retina but the accumulation of phagosome-like inclusions was accompanied by disorganisation in the apices of ...
- Published
- 1996
48. Ultrastructural evidence of intestinal mucosal macrophage activation after bone marrow transplantation
- Author
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Robert Horne, John Papadimitriou, Wendy N. Erber, B. J. Collins, and Geoffrey M Forbes
- Subjects
Adult ,Male ,Pathology ,medicine.medical_specialty ,Graft vs Host Disease ,chemical and pharmacologic phenomena ,Biology ,CD16 ,Transplantation, Autologous ,Pathology and Forensic Medicine ,Pathogenesis ,Colon, Sigmoid ,immune system diseases ,medicine ,Humans ,Transplantation, Homologous ,Macrophage ,Intestinal Mucosa ,Bone Marrow Transplantation ,Lamina propria ,Receptors, IgG ,Macrophage Activation ,Middle Aged ,medicine.disease ,Immunohistochemistry ,Transplantation ,Microscopy, Electron ,surgical procedures, operative ,Graft-versus-host disease ,medicine.anatomical_structure ,Immunology ,Female ,Bone marrow - Abstract
Summary Previous studies have demonstrated upregulation of intestinal mucosal macrophage CD16 (an Fc receptor for IgG) in bone marrow transplant (BMT) recipients with graft-versus-host disease (GVHD). We sought to determine whether there was ultrastructural evidence of mucosat macrophage activation in allogeneic BMT recipients and relate appearances to those seen in autologous BMT patients and to immunohistological findings. Sigmoid colonic mucosal biopsies from five allogeneic and three autologous BMT patients were taken prior to, 30 days after transplant and, in three of the allogeneic patients, 120 days after transplant. These were examined by immunohisto-chemistry and electron microscopy. Immunohistological analysis revealed upregulation of lamina propria macrophage CD16 after transplant in all patients except one autologous BMT recipient; there were no such changes in total macrophage numbers. Ultrastructural evidence of lamina propria macrophage activation was prominent after both allogeneic and autologous BMT. There was an increase in nuclear size accompanied by increased euchromatin and larger nucleoli. In the cytoplasm there were increased numbers of lysosomes, many of which were small and cylindrical, and cytoplasmic flaps were prominent. Phagosomes were less numerous after transplant. These data confirm that after BMT intestinal mucosal macrophages become activated. However changes in macrophage uttrastructure specific to patients at risk of developing clinical GVHD are lacking.
- Published
- 1996
49. Acute labyrinthitis associated with systemicCandida albicansinfection in ageing mice
- Author
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Alma Fulurija, John Papadimitriou, and Robert B. Ashman
- Subjects
Aging ,Pathology ,medicine.medical_specialty ,Time Factors ,Membranous labyrinth ,Mice ,Labyrinthitis ,Risk Factors ,Utricle ,otorhinolaryngologic diseases ,medicine ,Animals ,Inner ear ,Candida albicans ,biology ,business.industry ,Candidiasis ,General Medicine ,medicine.disease ,biology.organism_classification ,Corpus albicans ,medicine.anatomical_structure ,Otorhinolaryngology ,Ear, Inner ,Acute Disease ,Mice, Inbred CBA ,Vestibular membrane ,Female ,sense organs ,Saccule ,business - Abstract
The yeastCandida albicansis an important opportunistic pathogen that has been associated with disease of the inner ear. This study describes the histopathology of acute labyrinthitis caused by systemic infection with C.albicansin ageing inbred mice. Within four days after infection, yeast and hyphal forms of C.albicanswere found in the membranous labyrinth. The utricle and the adjacent parts of the ampullary regions of the semicircular canals were most severely affected, but damage was also seen in the scala media, the Scala tympani, the saccule, and the scala vestibuli. In the utricle, the lining epithelium of the membranous labyrinth was disrupted, and the lining cells of the vestibular membrane showed foci in which the membrane was disrupted. The data suggest that age may represent a risk factor for fungal labyrinthitis.
- Published
- 1996
50. The genotype of bone marrow-derived inflammatory cells does not account for differences in skeletal muscle regeneration between SJL/J and BALB/c mice
- Author
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John Papadimitriou, Miranda D. Grounds, and Christopher A. Mitchell
- Subjects
Male ,Muscle tissue ,Pathology ,medicine.medical_specialty ,Histology ,Genotype ,Bone Marrow Cells ,Mice, Inbred Strains ,Inflammation ,Carrageenan ,Wounds, Nonpenetrating ,Pathology and Forensic Medicine ,BALB/c ,Mice ,Necrosis ,Phagocytosis ,Species Specificity ,Tibialis anterior muscle ,Leukocytes ,medicine ,Animals ,Regeneration ,Bone Marrow Transplantation ,Mice, Inbred BALB C ,biology ,Macrophages ,Muscles ,Skeletal muscle ,Cell Biology ,Hematopoietic Stem Cells ,biology.organism_classification ,medicine.disease ,Hindlimb ,Transplantation ,medicine.anatomical_structure ,Radiation Chimera ,Female ,Bone marrow ,medicine.symptom ,Infiltration (medical) - Abstract
This study determined whether the genotype of bone marrow-derived inflammatory cells contributes to the more pronounced leukocytic exudation and extensive new muscle formation seen in SJL/J compared with BALB/c mice after a crush-injury (Mitchell et al. 1992). Female SJL/J mice were whole-body irradiated and reconstituted with male bone marrow from the BALB/c strain, and irradiated BALB/c females reconstituted with male SJL/J bone marrow. The mice were allowed to recover for 3 weeks and the tibialis anterior muscle (in a leg which had been protected from irradiation) was injured by crushing. At 3 and 10 days after injury the extent of necrotic debris, mononuclear leukocytic infiltration and new muscle formation was assessed in the muscles. The SJL/J mice reconstituted with BALB/c bone marrow showed extensive mononuclear leukocytic infiltration and clearance of necrotic debris when compared with BALB/c mice reconstituted with SJL/J bone marrow, and these strain-specific differences mirrored those seen with control bone marrow reconstituted hosts and non-irradiated hosts. The results show that the genotype of the bone marrow-derived macrophages is not responsible for the superior regeneration of crush-injured skeletal muscle in SJL/J mice, and it appears that factors intrinsic to the muscle tissue may be of central importance.
- Published
- 1995
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