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101.
Oral submucous fibrosis (OSF), a chronic oral mucosal condition commonly found in south Asians, is a disorder characterized by a quantitative as well as a qualitative alteration of collagen deposition within the subepithelial layer of the oral mucosa. Since degradation of collagen by fibroblast phagocytosis is an important pathway for physiological remodelling of soft connective tissues, we have investigated phagocytosis of collagen- and fibronectin-coated latex beads by fibroblast cultures with an in vitro model system. Coated fluorescent latex beads were incubated with human oral mucosa fibroblasts and the fluorescence associated with internalized beads was measured by flow cytometry. Cells from normal tissues that had been incubated with beads for 16 h contained a mean of 75% collagen phagocytic cells and 70% fibronectin phagocytic cells; however, about 15% and 10% of phagocytic cells individually contained more than twice the mean number of beads per cell. In contrast, cells from OSF tissues exhibited a 40% reduction of the proportions of collagen phagocytic cells (mean=35%) and a 48% decrease of the proportions of fibronectin phagocytic cells (mean=22%), none of the cells having a high number of beads as compared to normal fibroblasts. OSF lesions appear to contain fibroblasts with marked deficiencies in collagen and fibronectin phagocytosis. To investigate if inhibition of phagocytosis could be demonstrated in vitro, normal fibroblast cultures were incubated with areca nut alkaloids (arecoline, arecaidine). The cultures had a dose-dependent reduction in the proportions of phagocytic cells. On the other hand, corticosteroid used in the treatment of OSF exhibited a dose-dependent enhancement in the proportion of phagocytic cells. Therefore, our hypothesis for OSF, although oversimplified, is that betel nut alkaloids (arecoline, arecaidine) inhibit fibroblast phagocytosis and this provides a mechanism for the development of OSF. The benefit of a local intralesional injection of corticosteroid is also possibly, at least in part, through an enhancement of fibroblast collagen phagocytosis. 相似文献
102.
Medicare spends more than $200 billion a year; the politics surrounding the Medicare program cannot be fully understood without an adequate appreciation of that fact. An understanding of the political economy of Medicare is perhaps best achieved by thinking along three dimensions: (1) Medicare as redistributive politics; (2) Medicare as special-interest politics; and (3) Medicare as distributive politics. Seeing the extent to which Medicare policies flow from these political processes makes clear that Medicare reform and broader political reform are, at some level, inseparable and indistinguishable. 相似文献
103.
CC Leong JV Marley S Loh N Milech BW Robinson MJ Garlepp 《Canadian Metallurgical Quarterly》1997,71(3):476-482
A 56-year-old female with rheumatoid arthritis was admitted because of bilateral hip pain. In a few months of her hospitalization, a relatively abrupt renal dysfunction was emerged besides complement breakdown, and renal biopsy revealed crescentic glomerulonephritis. Immunofluorescence study showed peripheral granular deposits of IgG, IgM, and C3 in the glomeruli. Cresents were predominantly composed of macrophages and glomerular epithelial cells. Amyloid nephropathy, renal vasuculitis, and association of other collagen vascular diseases were negligible for the causative factor. It was suggested that immune complexes were formed in the glomeruli, in which both humoral and cellular immune responses were to be induced, that brought cescents formation in the lesions. Crescentic glomerulonephritis in patients with rheumatoid arthritis is rare and a possible pathogenetic mechanisms involved in the development of renal dysfunction are discussed with the special reference to immune complex-induced inflammation. 相似文献
104.
Urolithiasis has an incidence of about 12% in men and about 5% in women before the age of 70 years. Several epidemiological factors are involved in the predisposition to the urinary stone disease, notably: age, sex, race, climate, geography, profession, social class, nutritional factors and inherent genetic particularities. A number of physicochemical mechanisms govern lithogenesis, passing from saturation and supersaturation of urine to nucleation, crystallization and crystal growth to clinically significant sizes when the inhibition mechanisms are overwhelmed or absent. Generally urinary stone are of diverse aetiologies, that can essentially be grouped in calcium, uric acid, cystine and magnesium ammonium phosphate stones with subgroups in relation to the varied pathophysiological mechanisms involved in each case. 相似文献
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MA Quera-Salva C Guilleminault B Claustrat R Defrance P Gajdos CC McCann J De Lattre 《Canadian Metallurgical Quarterly》1997,20(12):1145-1150
OBJECTIVE: To describe the changes in the characteristics of human immunodeficiency virus (HIV)-related deaths in children with perinatally acquired infection. METHODS: A retrospective review of all deaths that occurred in HIV-infected children managed at The New York Hospital-Program for Children with AIDS during a 7-year period from January, 1990, to December, 1996. Differences in the characteristics at death between 15 children who died in 1990 and 10 children who died in 1996 were analyzed. RESULTS: Fifty-eight deaths in our cohort of HIV-infected children were identified during the 7-year period. The mean age at death was 4.43 years. Sixty-nine percent of children were black, 55% were male and 94% were receiving Medicaid. The mean weight/age Z score was -3.9 and the mean CD4 index was 0.067 with 65% having <50 CD4 cells/microl at the time of death (TOD). The most common organ/organ systems to be involved at the TOD were lung (78%) and central nervous system (61%). Mycobacterium avium complex (MAC) was the most common isolate at the TOD (26%) followed by Pneumocystis carinii (20%) and Pseudomonas aeruginosa (17%). The leading non-infectious cause of death was cardiac failure (9%). Comparison of the characteristics at the TOD between 1990 and 1996 revealed significant differences in mean age (2.1 vs. 9.2 years, P < 0.0001), mean CD4 count index (0.18 vs. 0.02, P < 0.03), mean number of organ/organ system involvement (3.9 vs. 5.9, P < 0.05), percent receiving antiretroviral therapy (33% vs. 70%, P < 0.02), mean number of years receiving antiretroviral therapy (0.88 vs. 3.86 years, P < 0.01), percent receiving P. carinii pneumonia prophylaxis (27% vs. 100%, P < 0.001), percent receiving MAC prophylaxis/therapy (0% vs. 100%, P < 0.0001), and cause of death from P. carinii pneumonia (53% vs. 0%, P < 0.01). CONCLUSIONS: Compared with children who died in 1990, HIV-infected children who died in 1996 were significantly older, more lymphopenic and more likely to have a greater number of organ system involvements and to have received antiviral therapy and antimicrobial prophylaxis. In 1996 no child died of P. carinii pneumonia. In 1996 MAC and P. aeruginosa were the two most important opportunistic infections causing death. These changes in the characteristics at death will warrant review of resources used in treating these children and may be critical in advising parents and care givers about the prognosis of this chronic infection. 相似文献
107.
We measured the incidence of cuff retear and injury to the suprascapular nerve after mobilization and repair of a massive rotator cuff tear. Of one hundred four rotator cuff repairs performed over a 5-year period, 10 patients (7 men and 3 women, age range 22 to 68 years) had primary repairs of massive rotator cuff tears requiring cuff mobilization and an acromioplasty as their only procedure. These patients were evaluated at a mean of 2.5 years (range 2.0 to 3.0 years) after surgery. At follow-up electromyographic examination confirmed that 1 of the 10 patients had an iatrogenic suprascapular nerve injury, whereas ultrasound evaluation revealed that 2 of 10 repairs failed. Pain relief was achieved in the eight patients with intact repairs and not in the two with recurrent tears. All patients had some limitation of active motion or strength, especially in external rotation. Thus 7 of 10 patients had neither evidence of nerve injury nor recurrent rotator cuff tears yet still showed limited active motion or weakness. It appears that operative injury to the suprascapular nerve during cuff mobilization can occur, but other factors such as inadequate cuff muscle function are more frequently responsible for the poor functional outcomes seen after successful repairs of massive rotator cuff tears. 相似文献
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KB Avraham T Hasson T Sobe B Balsara JR Testa AB Skvorak CC Morton NG Copeland NA Jenkins 《Canadian Metallurgical Quarterly》1997,6(8):1225-1231
Deafness is the most common form of sensory impairment in humans. Mutations in unconventional myosins have been found to cause deafness in humans and mice. The mouse recessive deafness mutation, Snell's waltzer, contains an intragenic deletion in an unconventional myosin, myosin VI (locus designation, Myo6). The requirement for Myo6 for proper hearing in mice makes this gene an excellent candidate for a human deafness disorder. Here we report the cloning and characterization of the human unconventional myosin VI (locus designation, MYO6) cDNA. The MYO6 gene maps to human chromosome 6q13. The isolation of the human gene makes it now possible to determine if mutations in MYO6 contribute to the pathogenesis of deafness in the human population. 相似文献