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991.
Critchley Hilary O.D.; Bailey Deborah A.; Au Chak L.; Affandi Biran; Rogers Peter A.W. 《Human reproduction (Oxford, England)》1993,8(10):1632-1639
The bleeding problems experienced by users of subdermal levonorgestrelimplants (Norplant) remain unexplained. The aim of the presentstudy was to investigate the oestrogen (ER) and progesteronereceptor (PR) distribution in levonorgestrel-treated endometrialbiopsies from 31 subjects recruited in Jakarta, Indonesia, andto compare the sex steroid receptor immunostaining with thatof endometrium from 58 normally cycling women from Melbourne,Australia. Sex steroid receptor immunoreactivity was additionallycompared with days of exposure to subdermal levonorgestrel,serum oestradiol and progesterone levels and days of bleedingduring a 90-day reference period. An immunohistochemical techniquewith an alkaline phosphatase anti-alkaline phosphatase (APAAP)detection system for use in formalin-fixed paraffin wax embeddedendometrial tissue was employed. Significantly greater meanimmunostaining scores of stromal PR were observed in Norplantcompared with control endometrium at all stages across the cycle.No significant correlations were demonstrated between sex steroidreceptor immunostaining and days of exposure to subdermal levonorgestrel,serum oestradiol or progesterone concentrations or days of bleedingduring a 90-day reference period. Whether the elevated stromalPR immunostaining in Norplant-treated endometrium is a consequenceof increased synthesis or reduced turnover of receptor remainsunclear. As yet it is undetermined whether increased PR immunoreactivitycorresponds to an increase in number of functional PR. 相似文献
992.
Early onset of autoimmunity in MRL/++ mice following immunization with beta 2 glycoprotein I.
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A L Aron M L Cuellar R L Brey S Mckeown L R Espinoza Y Shoenfeld A E Gharavi 《Clinical and experimental immunology》1995,101(1):78-81
Antiphospholipid antibodies (aPL) are associated with thrombosis, thrombocytopenia and recurrent fetal loss in humans and in some animal models. Immunization with beta 2 glycoprotein I (beta 2GPI) induced aPL production in normal rabbits and mice. However, the association of these antibodies with disease manifestations remains controversial. To determine whether induction of aPL by beta 2GPI immunization in an autoimmune strain of mice (MRL/++) would result in acceleration of clinical and serological autoimmune disease manifestations, three groups of 8-week-old female mice were studied. One group was immunized with beta 2GPI, and one with ovalbumin (OVA); the third was not immunized. After two booster injections, sera were analysed for the presence of anticardiolipin (aCL) and anti-DNA by ELISA and anti-nuclear antibody (ANA) by immunofluorescence. Mice were studied for thrombocytopenia, proteinuria, fecundity rates, litter sizes and the development of central nervous system dysfunction. Elevated levels of aCL, anti-DNA and ANA were detected in all beta 2GPI-immunized, in three OVA-immunized, and in none of the unimmunized mice. The anti-DNA antibodies were inhibited by CL micelles, suggesting cross-reactivity between aCL and anti-DNA. Platelet counts, fecundity rates and litter size were reduced in beta 2GPI-immunized but not in OVA-immunized or unimmunized mice. None of the mice developed neurological dysfunction or significant proteinuria over a 10-week period post-immunization. These findings suggest that beta 2GPI immunization induces aPL in MRL/++ mice associated with accelerated autoimmune manifestations resembling the antiphospholipid syndrome. 相似文献
993.
Vendeville B.; Baran D.; Gascon-Barre M.; Rubin E.; Luu T.; Vallieres S. 《Nephrology, dialysis, transplantation》1995,10(11):2020-2026
BACKGROUND.: Mercuric chloride (HgCl2 induces a lymphoproliferative disorderand autoimmune glomerulonephritis in Brown Norway (BN) rats.This syndrome is the consequence of T cell-dependent polyclonalB cell activation and autoantibody production. We have previouslyshown that HgCl2-induced autoimmune perturbations can be preventedin BN rats by the administration of cyclosporin A (CsA). Themost potent vitamin D3 metabolite 1,25(OH)2 D3 (Vit D3) sharescertain immunomodulatory properties with CsA. We therefore choseto compare the effects of Vit D3 to those of CsA in BN ratstreated with HgCl2 in order to establish whether Vit D3 eitheralone or in combination with CsA can attenuate an autoimmunesyndrome in vivo. METHODS.: BN rats were treated with HgCl2 according to a standard protocol.Subgroups of rats were also given CsA alone, Vit D3 or syntheticanalogues of Vit D3 alone, or combinations of both agents. Differentdoses and routes of administration were compared. The followingmarkers of disease activity were evaluated: mortality, peakproteinuria, serum IgE concentrations, and renal immunoglobulindeposition. RESULTS.: Disease activity was markedly attenuated in all rats treatedwith CsA alone. Vit D3 and certain of its synthetic analoguesadministered alone also tempered the autoimmune process, butto a lesser extent than did CsA. The effect of CsA alone wasso potent, that no additive or synergistic effects could bedemonstrated when CsA was administered in combination with VitD3. CONCLUSIONS.: Despite similar described immunomodulatory effects in vitro,CsA is clearly more effective than Vit D3 in preventing HgCl2autoimmune disease in BN rats. This suggests that there is adifference in the cellular targets of these two agents in vivo,and/or a difference in the potency with which HgCl2-triggeredimmune activation is suppressed. 相似文献
994.
Ayala Stabholz Anne A. Nicholas Grenith J. Zimmerman Ulf M. E. Wikesjö 《Journal of clinical periodontology》1998,25(10):794-800
Abstract. 15 adults, each providing 4 non-adjacent untreated periodontal pockets with a probing depth (PD) exceeding 6 mm. volunteered for a randomized, split-mouth, double-blind, clinical study evaluating subgingival irrigation with chlorhexidine (CHX) or tetracycline HCl (TTC). The study protocol included oral hygiene instructions followed by scaling and root planing. Experimental and immediately adjacent teeth did not receive instrumentation. The 4 deep periodontal pockets in each patient were assigned to be irrigated with 150 ml CHX (0.12%). TTC (10 or 50 mg/ml; TTC10, TTC50), or sterile saline (control) in a single episode. Post-irrigation mechanical plaque control was supported by 2× daily CHX rinses throughout the 12-week observation interval. Recordings of oral hygiene (PlI), gingival health (GI). bleeding on probing (BoP). probing depth (PD), clinical attachment level (CAL), and microbial morphotypes from subgingival paper point samples were performed pre-irrigation. and at 1, 2, 4, 6, 8, 10, and 12 weeks post-irrigation. Mean post-irrigation PlI was low, fluctuating between 0.0 and 0.4, without significant differences between experimental groups. Mean pre-irrigation GI approximated 1.4 and reached 0.8 at the exit of study without significant differences between experimental groups. All experimental sites exhibited BoP pre-irrigation. BoP was significantly reduced in TTC50 compared to TTC10, CHX and control sites from week 8 post-irrigation. PDs were reduced for the experimental groups with TTC50 exhibiting the strongest reduction. CALs remained unaltered from pre-irrigation for TTC10. CHX and control sites over the 12-week observation interval, whereas TTC50 sites consistently improved to significantly differ from all other groups at week 10 and 12 post-irrigation. The distribution of bacterial morphotypes was significantly altered towards one of periodontal health for all experimental groups with a profound effect for TTC50 sites. Our results suggest that subgingival irrigation with TTC solutions at high concentrations may have a rôle in the management of adult periodontitis. 相似文献
995.
Homeostasisof11ematopoiesisiscontrollednotoillybytheproliferationanddifferentiationofcells,butalsobycelldeath.Inadditiontolossofcontrolofcellproliferation,disruptionofapoptosis--inducedf[lnctionalsocontributestotumordevelopment.Althoughdiversesignalscaninduceapoptosisinawidevarietyofcelltypes,anumberofevolutionarilyconservedgenesregulateafinalcommoncelldeathpathway,thatisconservedinmanyspeciesfromwormstohumansll].Thehcf--2proto--oncogeneisoneofthecrucialapoptosisantagonizinggenes.Highlevelofhc… 相似文献
996.
997.
F. Centis C. Delfini F. Agostinelli I. Barbanti M. Annibali G. Lucarelli 《European journal of haematology》1995,54(5):329-333
Abstract: This study analyzes the serum transferrin receptor (sTfR) levels in a series of 230 ex-thalassemics with a follow-up of 1 to 9 years after bone marrow transplantation (BMT) for homozygous β thalassemia. Ex-thalassemics are individuals, cured of homozygous β thalassemia by BMT, who maintain different degrees of iron overload acquired during the pretransplant period. Both in experimental and clinical conditions, sTfR concentrations have been shown to be a quantitative measure of body iron status. This study was carried out to assess whether the level of sTfR may be of help in determining the extent of iron overload in ex-thalassemics. Patients who received the marrow from their HLA-identical sibling donor heterozygous for β thalassemia, namely heterozygous ex-thalassemics, displayed significantly higher levels of sTfR than patients transplanted from their normal sibling donors (normal ex-thalassemics). This finding suggests that increased erythropoiesis, albeit in part ineffective in heterozygous ex-thalassemics, is responsible for the sTfR increment. Both heterozygous and normal ex-thalassemics had significant lower sTfR levels than their heterozygous (p < 0.003) or normal (p < 0.0001) donors, respectively. These differences may be ascribed to the presence of iron overload in ex-thalassemics in comparison to their normal or heterozygous donors who did not present excess of iron in the body. A significant inverse correlation between sTfR and serum ferritin levels (r = –0.54, p < 0.0001) was found when normal ex-thalassemics were considered. In heterozygous ex-thalassemics, the lack of correlation between these two parameters may be explained by the enhanced erythropoietic activity of individuals with thalassemic trait. These results suggest that the level of sTfR may be a useful indicator of iron overload in normal ex-thalassemics. 相似文献
998.
Proteolytic Processing Mechanisms in the Biosynthesis of Neuroendocrine Peptides: The Subtilisin-like Proprotein Convertases 总被引:1,自引:0,他引:1
Yves Rouill Stephen J. Duguay Kaare Lund Machi Furuta Qiuming Gong Gregory Lipkind Anthony A. Oliva Jr. Shu Jin Chan Donald F. Steiner 《Frontiers in neuroendocrinology》1995,16(4)
The recent discovery of a novel family of precursor processing endoproteases has greatly accelerated progress in understanding the complex mechanisms underlying the maturation of prohormones, neuropeptides, and many other precursor-derived proteins. At least six members of this family have been found thus far in mammalian species, several having alternatively spliced isoforms, and related enzymes have been identified in many invertebrates, including molluscs, insects, nematodes, and coelenterates. The proprotein convertases are all dependent on calcium for activity and all possess highly conserved subtilisin-like domains with the characteristic catalytic triad of this serine protease (ordered Asp, His, and Ser along the polypeptide chain). Two members of this family, PC2(SPC2) and PC1/PC3(SPC3), appear to play a preeminent role in neuroendocrine precursor processing. Both convertases are expressed only in the brain and in the extended neuroendocrine system, while another important family member—furin/PACE (SPC1)—is expressed more ubiquitously, in almost all tissues, and at high levels in liver. SPC2 and SPC3 exhibit acidic pH optima and other properties which enhance their activity in the acidic, calcium-enriched environment of the dense-core secretory granules of the regulated pathway in neuroendocrine cells, while furin has a neutral pH optimum and is localized predominantly to the trans Golgi network where it is retained by a C-terminal transmembrane domain. Furin processes a wide variety of precursors in the constitutive pathway, such as those of growth factors, receptors, coagulation factors, and viral glycoproteins. Recent findings on the processing of proopiomelanocortin, proinsulin, proglucagon, and several other neuroendocrine precursors by SPC2 and SPC3 are discussed, along with information on the structure, properties, evolution, developmental expression, and regulation or the convertases. An inherited defect in the fat/fat mouse which affects the processing of proinsulin, and probably also many other prohormones, due to a point mutation in carboxypeptidase E has recently been identified and has begun to provide new insights into the functional integration of the individual processing steps. 相似文献
999.
Katherine Wiegmann Shylaja Muthyala Duk Hwan Kim Barry G. W. Arnason Ewa Chelmicka-Schorr 《Journal of neuroimmunology》1995,56(2)
Chronic/relapsing experimental allergic encephalomyelitis (CREAE) serves as an animal model for relapsing/remitting multiple sclerosis. Treatment with the β-adrenergic agonist isoproterenol or the β2-adrenergic agonist terbutaline significantly suppressed both the first acute attack and the number of relapses in CREAE Lewis rats. The number of relapses was decreased even when treatment with β-adrenergic agonist was started after the onset of the first acute attack of CREAE. β-adrenergic receptor number was increased significantly on splenocytes from CREAE rats as compared to healthy controls or CFA-injected rats. Terbutaline treatment of CREAE rats lowered the splenocyte receptor number to normal values. 相似文献
1000.
Peripheral blood CD3 and CD4 T-lymphocyte reduction correlates with severity of liver cirrhosis 总被引:2,自引:0,他引:2
L. Lombardo A. Capaldi G. Poccardi P. Vineis 《International Journal of Clinical & Laboratory Research》1995,25(3):153-156
Summary Immunological disturbances with impairment of immune function and a higher incidence of lymphoproliferative disorders and
other malignancies have been described in liver cirrhosis patients. To investigate the pathogenetic mechanism(s) involved
in such associated we looked for a possible imbalance in peripheral blood T-lymphocyte subpopulations in patients with liver
cirrhosis of differing severity. Immunophenotyping and counts of peripheral blood T-lymphocyte subpopulations were carried
out using monoclonal antibodies conjugated with different fluorochromes in 31 consecutive cirrhotic patients and 23 matched
healthy volunteers. Univariate and multivariate analyses of lymphocyte phenotype counts were performed and odds ratios were
computed. Statistically significant associations, according to both univariate and multivariate analyses, were found between
case/control status and mean CD3 and CD4 T-lymphocyte counts (P<0.0001). A strong correlation was found between the Pugh’s index and CD3 and CD4 lymphocyte counts, with a clear reduction
of these phenotypes with increasing liver cirrhosis. Median CD3 and CD4 values were 2,283 and 1,329/μl respectively among
controls and 896, 801, and 492/μl and 515, 514, and 307/μl, respectively in categories A, B, and C of Pugh’s classification.
Very high odds ratios were found using the median values of CD3 and CD4 as a threshold. There was a statistically significant
decrease for each of the T-cell phenotypes studied (CD2, CD3, CD4, CD8, CD16, CD19, CD20, CD56, CD57) between patients and
controls (P<0.0001). The progressive and severity-related decrease in mean peripheral blood CD3 and CD4 counts in liver cirrhosis suggests
a progressive impairment of protective immune function and may be a factor facilitating malignancy in cirrhotic patients. 相似文献