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31.
Plasma levels of endothelin-1 in retinitis pigmentosa   总被引:1,自引:0,他引:1  
Retinitis pigmentosa (RP) is an inherited retinal disorder clinically characterized by a pale, waxy optic nerve head, attenuated retinal blood vessels and bone spicule pigment in the retina. Hemodynamic studies have demonstrated that RP is associated with a reduction in the retinal and choroidal blood flow. Retinal hemodynamic impairment is also present in the early stages of RP and various hypotheses have been advanced as to its cause. The authors studied 20 patients, 12 males and 8 females, aged between 26 and 42 years (mean 34.6 years) affected by simplex RP. The twenty patients were divided in two groups according to the degree of sight impairment: group A consisted of 10 patients with a visual acuity of 0.3 +/- 0.1, visual field mean defect 18.988 +/- 3.419 dB and b-wave electroretinogram amplitude of 13.14 +/- 0.308 microV. Group B consisted of 10 patients with a visual acuity of 0.8 +/- 0.2, visual field MD 10.523 +/- 3.582 dB and b-wave electroretinogram amplitude of 26.000 +/- 0.757 microV. An increase in plasma levels of endothelin-1 (ET-1) was found as compared with healthy controls: 1.910 +/- 0.617 pg/ml vs. 1.180 +/- 0.210 pg/ml (p < 0.021), but there was no statistical difference between group A and B (p < 0.163). It is thought that an increase in ET-1 and retinal oxygen levels in RP could lead to vasoconstriction and a decrease in the retinal blood flow worsening the abiotrophic process.  相似文献   
32.
Reproductive-tract anomalies after administration of the potent oestrogen, diethylstilboestrol, in pregnant women raised concerns about the reproductive effects of exposure to weakly oestrogenic environmental contaminants such as bis[4-chlorophenyl]-1,1,1-trichloroethane (p,p'-DDT) or its metabolites, such as bis[4-chlorophenyl]-1,1-dichloroethene (p,p'-DDE). We measured p,p'-DDT and p,p'-DDE in preserved maternal serum samples drawn 1-3 days after delivery between 1960 and 1963. We recorded time to pregnancy in 289 eldest daughters 28-31 years later. Daughters' probability of pregnancy fell by 32% per 10 microg/L p,p'-DDT in maternal serum (95% CI 11-48). By contrast, the probability of pregnancy increased 16% per 10 microg/L p,p'-DDE (6-27). The decreased fecundability associated with prenatal p,p'-DDT remains unexplained. We speculate that the antiandrogenic activity of p,p'-DDE may mitigate harmful androgen effects on the ovary during gestation or early life.  相似文献   
33.
Laminin is the main noncollagenous constituent of the basement membrane, and its serum levels could reflect the metabolic changes that occur in the basement membrane. Severe endothelial injury with thickening of basement membrane is a characteristic feature of thrombotic microangiopathy (TMA). With this background, the aim of the study was to investigate in a prospective way (1) the relationship among serum Lam-P1, the extent of renal histopathologic lesions, and the biochemical parameters commonly used as markers of TMA activity, and (2) the usefulness of serum Lam-P1 concentrations as a renal outcome prognostic index. To this end, 18 consecutive patients with active biopsy-proven TMA with renal involvement were studied. One hundred and twenty-one healthy control subjects, 20 patients with systemic scleroderma without renal involvement, and 35 patients with systemic lupus erythematosus (20 without nephropathy and 15 with diffuse proliferative type 4 lupus nephritis) were used as control groups. In addition, to analyze the influence of either renal failure or hemodialysis therapy on serum Lam-P1 levels, 91 patients on regular hemodialysis therapy and 81 patients with predialysis chronic renal failure of different etiologies were included in the study. Serum Lam-P1 was determined by RIA at admission, on days 10 and 30 of follow-up in all patients, and after 6 and 12 mo of follow-up in all surviving patients. Serum lactate dehydrogenase, haptoglobin, platelet count, hemoglobin, and serum creatinine were determined as markers of endothelial dysfunction and hemolysis. At admission, serum levels of Lam-P1 were significantly higher in patients with TMA than in healthy control subjects (3.39 +/- 0.56 U/ml versus 1.40 +/- 0.18 U/ml; P < 0.0001). In addition, patients with TMA had significantly higher serum Lam-P1 levels than the other groups included in the study. At the first control, Lam-P1 correlated with lactate dehydrogenase (P = 0.006) and hemoglobin (P = 0.002). During follow-up, platelet count and hemolysis indicators normalized in all patients, while serum Lam-P1 decreased only in patients with renal function recovery. In multivariate analysis, serum creatinine and Lam-P1 at day 10 were the only independent predictors of renal outcome (r2 = 0.94; P < 0.0001) and also correlated with indices of histopathologic damage (P < 0.001). Serum Lam-P1 normalized in all patients with chronic renal failure in the samples obtained at 6 and 12 mo of regular hemodialysis after solving active TMA, thus suggesting that histopathologic lesions, but not renal function itself, would be mainly responsible for the high Lam-P1 serum concentrations detected in TMA. In conclusion, serum Lam-P1 concentrations are increased in patients with active TMA. Furthermore, patients with poor renal outcome show a prolonged increase of serum Lam-P1 that is related to the extent of renal histologic lesions. Unlike the biochemical markers of hemolysis commonly used to assess TMA activity, the sequential determination of serum Lam-P1 provides valuable information about long-term renal prognosis in patients with TMA.  相似文献   
34.
Vasoactive intestinal peptide (VIP) is a neuropeptide involved in the regulation of airway mucus secretion. The biological functions of VIP are mediated through two receptors, the vasoactive intestinal peptide receptor type 1 (VPAC1R) and type 2 (VPAC2R). The aim of this study was to quantify the expression of both VPAC1R and VPAC2R in the central airways of smokers with chronic bronchitis. Surgical specimens were obtained from 33 smokers undergoing thoracotomy for localised pulmonary lesions: 23 smokers with symptoms of chronic bronchitis and 10 asymptomatic smokers with normal lung function. By using immunohistochemical and microscopic analysis, an increased expression of VPAC1R, but not VPAC2R, was found in bronchial epithelium, bronchial glands and vessels of smokers with symptoms of chronic bronchitis compared with asymptomatic smokers. Smokers with symptoms of chronic bronchitis also had an increased number of mononuclear cells positive for both VPAC1R and VPAC2R in the bronchial submucosa. In conclusion, the expression of type 1 and type 2 vasoactive intestinal peptide receptors is increased in the central airways of smokers with chronic bronchitis, suggesting their possible involvement in the pathogenesis of chronic bronchitis.  相似文献   
35.
Effective therapy for prion diseases is currently unavailable. Recently, vaccination was shown to be effective in mouse models of a particular neurodegenerative conditions: Alzheimer's disease (AD). Here, we report that vaccination with synthetic oligopeptides homologous to the hamster (Mesocricetus auratus) prion protein augments survival time in animals infected intraperitoneally with 263K scrapie agent. For each hamster included in the study, prion-specific serum antibodies as well as deposition of pathological prion protein (PrP(res)), glial fibrillary acidic protein (GFAP), and mRNA expression for cytokines (TNF alpha, IL-1beta, IL-10) in brain tissues were evaluated. In immunized animals, increased survival after challenge was associated with a reduction of cerebral lesion, PrP deposition and GFAP expression; in these animals, anti-prion protein peptide antibody levels were increased, and the expression of pro-inflammatory cytokines (TNF alpha and IL-1beta) was reduced. Vaccination could be an effective therapeutic approach to postpone disease onset.  相似文献   
36.
The authors report the case of a malignant haemangiopericytoma found in an uncommon location, namely the mesorectum. Haemangiopericytomas of the mesorectum are rare mesenchymal tumours of vascular origin that usually occur in the musculature of the extremities, retroperitoneum, pelvis (uterus, ovary and urinary bladder), head, neck and lungs. Rare sites include the liver, pancreas, stomach and greater omentum. Because of their rarity the overall experience has not been significant and little has been published concerning such tumours. In addition, the difficult interpretation of the histological evidence and the poor prognosis of the disease may still give rise to problems in terms of clinical management. Haemangiopericytomas of the retrorectal space, however, seem to behave like malignant tumours: the clinical course is poor and survival short, despite radical surgery, due to early distant metastases and local recurrence. Surgery still remains the mainstay of treatment. Adjuvant therapies should be considered.  相似文献   
37.
BACKGROUND: Squamous cell carcinoma has a stronger association with tobacco smoking than other non-small cell lung cancers (NSCLC). A study was undertaken to determine whether chronic obstructive pulmonary disease (COPD) is a risk factor for the squamous cell carcinoma histological subtype in smokers with surgically resectable NSCLC. METHODS: Using a case-control design, subjects with a surgically confirmed diagnosis of squamous cell carcinoma were enrolled from smokers undergoing lung resection for NSCLC in the District Hospital of Ferrara, Italy. Control subjects were smokers who underwent lung resection for NSCLC in the same hospital and had a surgically confirmed diagnosis of NSCLC of any histological type other than squamous cell. RESULTS: Eighty six cases and 54 controls (mainly adenocarcinoma, n = 50) were enrolled. The presence of COPD was found to increase the risk for the squamous cell histological subtype by more than four times. Conversely, the presence of chronic bronchitis was found to decrease the risk for this histological subtype by more than four times. Among patients with chronic bronchitis (n = 77), those with COPD had a 3.5 times higher risk of having the squamous cell histological subtype. CONCLUSIONS: These data suggest that, among smokers with surgically resectable NSCLC, COPD is a risk factor for the squamous cell histological subtype and chronic bronchitis, particularly when not associated with COPD, is a risk factor for the adenocarcinoma histological subtype.  相似文献   
38.
Evidence indicates that ghrelin, an endogenous ligand of the growth hormone secretagogue receptor, controls the growth of several human and rat cell types cultured in vitro. Hence, we have investigated, by using both TUNEL and ELISA assays, the effects of 10(-8) M ghrelin on the basal apoptotic deletion rate of rat osteoblasts and thymocytes, rat and human adrenocortical cells, human umbilical vein endothelial cells, and human aldosteronoma cells cultured in vitro, as well as of the human adrenocortical carcinoma-derived cell lines NCI-H295 and SW-13. Both assays consistently showed that ghrelin did not affect apoptotic rate of normal rat and human cells, but significantly enhanced apoptotic deletion in aldosteronoma, NCI-H295 and SW-13 cell cultures. Due to the central role of apoptosis in the control of tumor growth, these findings, if confirmed in other tumor cell types, could suggest an antitumoral action of ghrelin.  相似文献   
39.
Polyphosphazenes are polymers possessing a skeleton composed of alternating phosphorous and nitrogen atoms, and two side-moieties linked to each phosphorous atom. Polyphosphazenes with amino acid esters as side-moieties are biocompatible and biodegradable polymers. Two polyphosphazenes, poly[bis(ethyl alanate) phosphazene] and poly[(ethyl phenylalanate)0.8(ethyl alanate)0.8(ethyl glycinate)0.4 phosphazene] (PPAGP) were synthesized, and processed to form small fibers. Their ability to support rat neuromicrovascular endothelial cell (EC) adhesion and growth has been studied, using poly(D,L-lactic acid) as reference compound. Scanning electron microscopy revealed that both poly[bis(ethyl alanate) phosphazene] and PPAGP fibers were thinner than poly(D,L-lactic acid) fibers, and possessed a more irregular and porous surface. All polymers increased EC adhesion, compared with polystyrene, but only polyphosphazenes were able to improve EC growth. The highest increase in EC proliferation was induced by PPAGP, which, as revealed by environmental scanning electron microscopy, was also able to induce ECs to arrange into tubular structures. The conclusion is drawn that PPAGP may provide the best scaffold for engineered blood vessels, because it promotes adhesion, growth, and organization of ECs into capillary-like structures.  相似文献   
40.
We compared 2 rules-based genotype interpretation systems and real or virtual phenotype through a retrospective analysis of a prospective trial. Genotypes were determined with VircoGEN II (VIRCO) and were interpreted with either RetroGram 1.4 or TRUGENE HIV-1 (guidelines 3.0) or original virtual phenotype (Virtual Phenotype; VIRCO), as available in the year 2000. Among 188 human immunodeficiency virus (HIV) type 1 isolates, overall concordance (kappa agreement) was observed for the 2 rules-based systems, whereas striking discordances were noted between them and real and virtual phenotype interpretations for stavudine, didanosine, zalcitabine, abacavir, and amprenavir (kappa<0.4). Clinical evaluation of a subset of 173 patients showed that both rules-based sensitivity scores were independently associated with HIV RNA loads <400 copies/mL at week 16 of during-treatment analysis (TRUGENE: odds ratio [OR], 2.90; 95% confidence interval [CI], 1.52-5.52; P=.001; RetroGram: OR, 2.34; 95% CI, 1.21-4.55; P=.012), whereas, in contrast to real or virtual phenotype, interpretations according to biological cut-offs were not (OR, 1.91; 95% CI, 0.77-4.76; P=.162).  相似文献   
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