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61.
Phenobarbital and clofibrate, two non-genotoxic carcinogens, have been
investigated regarding the relationship between reactive oxygen species,
antioxidant enzyme expression and apoptosis in primary cultures of rat
hepatocytes. Low toxicity concentrations, 200 and 100 microg/ml for
phenobarbital and clofibrate respectively, were used to examine their
effect on spontaneous or transforming growth factor beta1
(TGFbeta1)-induced apoptosis and on the expression of antioxidant defence
enzymes (superoxide dismutases and catalase). The increased incidence of
apoptotic nuclei was visualized in TGFbeta1-treated cultures with the
fluorescent dye Hoechst 33258 and was quantified under all experimental
conditions by measurement of the hypodiploid peak in DNA histograms
obtained by flow cytometry. Both substances, when added separately to
hepatocyte cultures and incubated for 24 and 48 h, significantly diminished
spontaneous apoptosis and exhibited a slight suppression of
TGFbeta1-induced apoptosis. Endogenous peroxide production by hepatocytes
increased with TGFbeta1, phenobarbital or clofibrate and the increase was
greater with phenobarbital and in the presence of TGFbeta1 with both drugs.
Gene expression of catalase and Mn- and Cu,Zn superoxide dismutases (SOD)
was evaluated by northern blot analysis of hepatocytes incubated in the
presence of phenobarbital or clofibrate with or without TGFbeta1 and the
following differences were detected: phenobarbital induced a significant
decrease in both dismutases (to 56%, P < 0.05, and 55%, P < 0.05, for
Mn- and Cu,Zn-SOD respectively) and a 2-fold increase (P < 0.01) in
catalase; clofibrate induced a slight decrease in both SODs and a 4-fold
increase (P < 0.05) in catalase; TGFbeta1 significantly decreased to 37%
(P < 0.05) expression of catalase while not significantly affecting
expression of both SODs. We conclude that inhibition of spontaneous
apoptosis induced by either phenobarbital or clofibrate is accompanied by
increases in the endogenous levels of peroxides and by significant
induction of catalase gene expression. Furthermore, the lack of effect of
both compounds on TGFbeta1-induced apoptosis could be a consequence of the
inability of these two compounds to counteract the depressing effect of
TGFbeta1 on expression of catalase.
相似文献
62.
Eberhart LH Högel J Seeling W Staack AM Geldner G Georgieff M 《Acta anaesthesiologica Scandinavica》2000,44(4):480-488
BACKGROUND: So far there are three different scores to predict postoperative vomiting (PV: Apfel et al., 1998) or postoperative nausea and vomiting (PONV: Koivuranta et al., 1997; Palazzo and Evans, 1993). All three scores used logistic regression analysis to identify and create weights for the risk factors for PV or PONV. In short, these were sex, age, history of previous PONV, motion sickness, duration of anaesthesia, and use of postoperative opioids. However, an external evaluation and a comparison of these scores has not been performed so far. METHODS: Patients undergoing a variety of surgical procedures under general anaesthesia were studied prospectively. Preoperatively, they completed a questionnaire concerning potential risk factors for the occurrence of PV or PONV implemented in the three risk scores. Balanced anaesthesia (induction agent, nondepolarising neuromuscular blocker, opioid, and inhalation agent in nitrous oxide/oxygen) was performed. No intravenous anaesthesia or any antiemetic prophylaxis was applied. Postoperatively, the patients were observed in the recovery room for the occurrence of PV and PONV and were visited twice on the ward within the 24-h observation period. Both the patients and the nursing staff were asked whether PV or PONV was present. The severity of PONV was categorised using a standardised scoring algorithm. A total of 1,444 patients was finally included into the analysis. Using information of the predicted risk for the individual patients and the actual occurrence of PV or PONV, Receiver Operator Characteristics (ROC-curves) were drawn. The area under each ROC-curve was calculated as a means of the predictive properties of each score and was compared for statistical differences. RESULTS: For prediction of PONV (any severity) the AUC-values (AUC=area under the curve) and the corresponding 95%-confidence intervals were: Apfel: 0.70 (0.67-0.72); Koivuranta: 0.71 (0.69-0.73); Palazzo: 0.68 (0.65-0.70). For prediction of PV: Apfel: 0.73 (0.71-0.75); Koivuranta: 0.73 (0.70-0.75); Palazzo: 0.68 (0.65-0.70). Thus, all three scores appeared to have a moderate accuracy as measured by the AUC. The score of Koivuranta predicts PONV (P=0.007) and also PV (P=0.002) significantly better than Palazzo's score. Furthermore, for predicting of PV the score of Apfel was also superior to Palazzo's score (P=0.005). All three scores predict PV with the same accuracy as PONV. CONCLUSION: The occurrence of PV and PONV in patients undergoing surgery under balanced anaesthesia can be predicted with moderate but acceptable accuracy using one of the available risk scores, regardless of local surgical or anaesthesiological circumstances. For clinical practice, we recommend the score published by Koivuranta, since its calculation is very simple. 相似文献
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AM Halefoglu 《Journal of Medical Imaging and Radiation Oncology》2005,49(3):242-245
A pulmonary arteriovenous fistula is an abnormal connection between pulmonary arteries and veins. Patients with Rendu–Osler–Weber syndrome may present with this vascular malformation, which is a typical finding of the disease. Approximately 5–15% of Rendu–Osler–Weber syndrome patients have pulmonary arteriovenous malformations (AVM) and there is usually a family history of AVM in these patients. The malformations are usually located in the lower lobes. In this paper, I describe a 49‐year‐old male patient with dyspnoea, cough, haemoptysis and epistaxis. Physical examination showed nasal telangiectasias, cyanosis of the lips and nails, and a systolic bruit over the left lung. Chest X‐ray revealed a 5‐cm mass in the left lower lobe and after magnetic resonance examination, together with 3‐D magnetic resonance angiography, it was demonstrated to be a pulmonary arteriovenous fistula. The history of a niece with a similiar history of suspected pulmonary arteriovenous fistula led me to consider the possibility of Rendu–Osler–Weber syndrome presenting with a pulmonary arteriovenous fistula. 相似文献
66.
BD White A Kong E Khoo AM Southcott 《Journal of Medical Imaging and Radiation Oncology》2005,49(4):319-321
Tracheobronchopathia osteochondroplastica (TO) is a rare benign disease characterized by the presence of osseous and cartilaginous submucosal nodules projecting into the tracheobronchial tree. Most cases are asymptomatic and discovered incidentally at post‐mortem. We identified a case of TO on thoracic spiral CT and confirmed the diagnosis on bronchoscopy. This article reviews the imaging characteristics of TO, and shows the 3‐D virtual bronchoscopic and multiplanar reconstruction appearances of TO. 相似文献
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Adipokines played a limited role in predicting temporary growth differences between very low birthweight infants with and without bronchopulmonary dysplasia 下载免费PDF全文
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