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81.
Cell cultures were derived from adult human brain biopsies [from cortical gray (cultures 9-HB-G and 33-HB-G) and white (culture 14-HB-W) and stroke-injured white matter (culture 33-HB-IW)]. The morphology and growth rate of cultured cells were examined and correlated with the presence of vimentin and glial fibrillary acidic protein (GFAP). The cultures from various brain matters differed in cell morphology and rate of growth but not in GFAP and vimentin staining. Cells of primary and rapidly proliferating cultures were GFAP-negative and vimentin-positive. Spontaneous growth deceleration occurred in culture 14-HB-W within passages 5 to 10 and in cultures 9-HB-G, 33-HB-G, and 33-HB-W within passages 17 to 20. This deceleration, as well as the successive complete growth arrest, were accompanied by an appearance of GFAP-positive cells and an elevated intensity for vimentin staining. We propose that GFAP-positive astrocytes originate from glial precursor cells that migrate from the explants and differentiate under prolonged subcultivation.  相似文献   
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83.
Responsiveness, the ability to detect meaningful clinical change, is a critical attribute of instruments used to evaluate outcomes of treatments. The authors hypothesized that self-administered symptom severity and functional status questionnaires are more responsive to clinical improvement after carpal tunnel release than traditional physical examination measures of strength and sensibility. Data were obtained from a randomized clinical trial of endoscopic versus open carpal tunnel release conducted in four university medical centers. Patients were evaluated before surgery and 3 months after surgery. Seventy-four patients indicating that they were more than 80% satisfied with the results of surgery were assumed to have clinically meaningful improvement and were the focus of the analysis. Evaluations included questionnaires assessing symptom severity, functional status, and activities of daily living as well as measurement of grip, pinch, and abductor pollicus brevis strength, and 2-point discrimination and Semmes-Weinstein pressure sensibility. Responsiveness was calculated with the standardized response mean (mean change/standard deviation of change) as well as the effect size (mean change/standard deviation of baseline values). The symptom severity scale was four times as responsive, and the functional status and activities of daily living scales were twice as responsive, as the measures of strength and sensibility. Self-administered symptom severity and functional status scales are much more responsive to clinical improvement than measures of neuromuscular impairment and should severe as primary outcomes in clinical studies of therapy for carpal tunnel syndrome.  相似文献   
84.
85.
Isolated left atrial mural endocarditis is rare. We report a case where the diagnosis was made clinically and supported by blood cultures and transoesophageal echocardiography. Appropriate intravenous antibiotics were administered and serial transoesophageal echocardiograms helped in monitoring the decrease in size and final disappearance of the vegetation, thus avoiding the need for surgical intervention.  相似文献   
86.
BACKGROUND: Many Helicobacter pylori strains produce a cytotoxin that induces cytoplasmic vacuolation in various types of eukaryotic cells. In contrast with the marked cell vacuolation that occurs in vitro in response to this cytotoxin, comparatively little epithelial vacuolation has been observed in the gastric mucosa of H pylori infected persons. AIMS: Experiments were performed to determine the susceptibility of human gastric epithelial cells in vitro to H pylori vacuolating cytotoxin activity. METHODS: Human gastric epithelial cells, harvested from upper gastrointestinal endoscopic biopsy specimens, were incubated overnight with broth culture supernatants from either a wild type cytotoxin producing (tox+) H pylori strain or an isogenic mutant strain that lacks cytotoxin activity. RESULTS: Prominent cytoplasmic vacuolation occurred in response to tox+ supernatant, but not supernatant from the isogenic mutant strain. Primary human gastric epithelial cells were significantly more sensitive to H pylori vacuolating cytotoxin activity than were either HeLa or AGS cells. Exposure of human gastric epithelial cells to high concentrations of tox+ supernatant for 48 hours caused lethal cell injury. CONCLUSIONS: These studies indicate that primary human gastric epithelial cells are highly sensitive to H pylori vacuolating cytotoxin activity.  相似文献   
87.
We investigated the effect of chronic exposure (3 days) with low-density lipoprotein (LDL) and oxidized (Ox)-LDL on the unstimulated and stimulated formation of prostacyclin (6-keto-prostaglandin [PG]F1 alpha) and total inositol phosphates (IPs) by cultured bovine aortic endothelial cells. Neither basal nor bradykinin-stimulated (1 to 10 nmol/L) formation of 6-keto-PGF1 alpha was affected by LDL, except at the highest concentration of bradykinin tested (100 nmol/L). In the presence of the antioxidants N-acetyl-L-cysteine (NAC, 10 mumol/L) or vitamin E (100 mumol/L), basal and bradykinin-stimulated formation of 6-keto-PGF1 alpha was potentiated by 20 micrograms protein/mL of LDL. Ox-LDL decreased unstimulated formation of the eicosanoid from 3.1 +/- 0.2 pg/micrograms protein in control cells to 1.6 +/- 0.1 and 0.5 +/- 0.1 pg/microgram protein after 3-day incubation with 5 and 20 micrograms protein/mL of Ox-LDL, respectively (P < .05). As in the basal state, Ox-LDL decreased bradykinin-induced 6-keto-PGF1 alpha formation. NAC or vitamin E did not influence Ox-LDL-induced endothelial cell changes in eicosanoid production. IPs formation by endothelial cells increased to a similar extent in the presence of 20 micrograms protein/mL of either LDL or Ox-LDL. However, no change was apparent in the bradykinin (10 mumol/L)-induced increase in total IPs formation after incubation with the lipoproteins. The data indicate that chronic exposure to Ox-LDL abolishes the production of prostacyclin by cultured endothelial cells. The oxidatively modified lipoprotein seems to more specifically affect the prostacyclin pathway.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
88.
Previous studies have shown that mu (mu) and kappa (kappa) opioid antagonists inhibit suckling-induced prolactin release. Prolactin responses elicited by pup suckling or opioid administration are mediated, at least in part, by suppression of dopamine (DA) release from tuberoinfundibular dopaminergic (TIDA) neurons in the hypothalamus. We examined the effects of the mu opiate receptor antagonist, beta-funaltrexamine (beta-FNA), and the kappa opiate receptor antagonist, nor-binaltorphimine (nor-BNI) on the activity of TIDA neurons in lactating rats. TIDA neuronal activity was determined by measuring DOPA accumulation in the caudate putamen (CP) and median eminence (ME). The effects of opioid antagonist treatment were determined in pup-deprived (low circulating prolactin levels) or pup-suckled rats (high circulating prolactin levels). The accumulation of 5-hydroxytryptophan (5-HTP) in the medial preoptic area (MPOA), the anterior hypothalamus (AH) and the median eminence (ME) was quantified as an index of serotonergic activity in the same animals for comparative purposes. In vehicle treated rats, suckling caused a significant and selective decrease in DOPA accumulation in the ME. beta-FNA (5 micrograms, i.c.v.) pretreatment significantly increased DOPA accumulation in the ME of pup-deprived and pup-suckled rats. beta-FNA pretreatment also prevented the suckling-induced suppression of DOPA accumulation in the ME. In contrast to the actions of beta-FNA, pretreatment with nor-BNI (8 micrograms, i.c.v.) did not significantly affect the activity of the TIDA neurons in pup-deprived or pup-suckled rats. Suckling alone did not alter 5-HTP accumulation in any of the brain regions examined, and neither opioid antagonist had appreciable effects on 5-HTP accumulation. These results demonstrate that the EOP tonically inhibit the TIDA neurons in both pup-deprived and pup-suckled, post-partum female rats by acting through the mu, but not the kappa, opiate receptor subtype. Furthermore, the suckling-induced inhibition of TIDA neurons is also mediated through the EOP acting at mu, but not kappa opioid receptors.  相似文献   
89.
Preretinal neovascularization and chronic retinal oedema are the two major sight-threatening complications that can occur during diabetic retinopathy. Ocular neovascularization is strongly associated with retinal ischaemia, and growth factors have been implicated in its pathogenesis. The ischaemic retina is assumed to secrete growth factors that stimulate residual vessels to proliferate. Interest has focused on basic fibroblast growth factor (bFGF), insulin-like growth factor-1 (IGF-1), platelet-derived growth factor (PDGF), transforming growth factor beta (TGF beta) and more recently vascular endothelial cell growth factor (VEGF). Histologic studies have demonstrated the presence of growth factor proteins and receptors and/or their mRNA, mainly VEGF, PDGF, and bFGF, in preretinal membranes of patients with proliferative diabetic retinopathy. Elevated intravitreal levels of IGF-1 and VEGF correlating with neovascular activity have been found in some patients. However, a direct causal relationship between ischaemia, growth factors and neovascularization has not been clearly demonstrated despite considerable research work. To date, the growth factor correlating most closely with neovascularization is VEGF. As many growth factors seem to be produced during the neovascular process, their specific inhibition probably will have limited effects. Laser photocoagulation of the retina has proved beneficial for regression of new vessels, probably through destruction of the ischaemic retina producing neovascular growth factors, and is currently the only treatment for proliferative diabetic retinopathy. Inhibition of IGF-1 by somatostatin analogs has produced unsatisfactory results. Other vascular inhibitors are currently being studied.  相似文献   
90.
We conducted a systematic review of what is known about the relationship between post-traumatic stress disorder (PTSD) and smoking to guide research on underlying mechanisms and to facilitate the development of evidence-based tobacco treatments for this population of smokers. We searched Medline, PsychINFO, and the Cochrane Central Register of Controlled Trials and identified 45 studies for review that presented primary data on PTSD and smoking. Smoking rates were high among clinical samples with PTSD (40%-86%) as well as nonclinical populations with PTSD (34%-61%). Most studies showed a positive relationship between PTSD and smoking and nicotine dependence, with odds ratios ranging between 2.04 and 4.52. Findings also suggest that PTSD, rather than trauma exposure itself, is more influential for increasing risk of smoking. A small but growing literature has examined psychological factors related to smoking initiation and maintenance and the overlapping neurobiology of PTSD and nicotine dependence. Observational studies indicate that smokers with PTSD have lower quit rates than do smokers without PTSD. Yet a few tobacco cessation treatment trials in smokers with PTSD have achieved quit rates comparable with controlled trials of smokers without mental disorders. In conclusion, the evidence points to a causal relationship between PTSD and smoking that may be bidirectional. Specific PTSD symptoms may contribute to smoking and disrupt cessation attempts. Intervention studies that test behavioral and pharmacological interventions designed specifically for use in patients with PTSD are needed to reduce morbidity and mortality in this population.  相似文献   
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