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71.
72.
Skin corrosion or irritation refers to the production of irreversible or reversible damage to the skin following the application of a test substance, respectively. Traditionally, hazard assessments are conducted using the in vivo Draize skin test, but recently in vitro tests using reconstructed human epidermis (RhE) models have gained regulatory acceptance. In this study, skin corrosion (SCT) and irritation tests (SIT) using a RhE model were implemented to reduce the number of in vivo tests required by regulatory bodies. One hundred and thirty-four materials were tested from a wide range of substance classes included 46 agrochemical formulations. Results were assessed according to UN GHS, EU-CLP, ANVISA and US EPA classification schemes. There was high correlation between the two in vitro tests. Assessment of the SCT sensitivity was not possible due to the limited number of corrosives in the data set; SCT specificity and accuracy were 89% for all classification systems. Accuracy (63–76%) and sensitivity (53–67%) were low in the SIT. Specificity and concordance for agrochemical formulations alone in both the SCT and SIT were comparable to the values for the complete data set (SCT: 91% vs. 89% specificity, 91% vs. 89% accuracy and SIT: 64–88% vs. 70–85% specificity, 56–75% vs. 63–76% accuracy).  相似文献   
73.
74.
Brain death impairs coronary endothelial function   总被引:4,自引:0,他引:4  
Szabo G  Buhmann V  Bahrle S  Vahl CF  Hagl S 《Transplantation》2002,73(11):1846-1848
BACKGROUND: To characterize the impact of brain death (BD) on endothelial dysfunction after cardiac transplantation we investigated coronary circulation and vasomotor function in a canine model. METHODS: Left ventricular pressure-volume data (conductance catheter) and coronary blood flow (CBF) were monitored continuously. Endothelium-dependent vasodilatation after acetylcholine and endothelium-independent vasodilation after sodium nitroprusside were assessed before and 3 hr after BD induction (inflation of a subdural balloon). RESULTS: BD led to an initial hyperdynamic reaction with significant (P<0.05) increase of CBF. After 3 hr, CBF decreased significantly (P<0.05). Although before BD, application of acetylcholine led to a monophasic vasodilatative response, after BD a short mild vasodilatation was followed by a longer vasoconstriction. Endothelium-independent vasodilatation remained unchanged. CONCLUSIONS: BD affects coronary circulation by two means: (1) impairment of CBF to decrease in parallel in afterload with consecutive hemodynamic deterioration and (2) severe endothelial dysfunction that may be a contributing factor to posttransplant outcome.  相似文献   
75.
The aim of the present study was to improve the viability of marginal livers from non-heart beating donors upon cold preservation using two different techniques for the provision of tissue aerobiosis. Livers from male Wistar rats (250-300 g bw) were harvested after 60 min of cardiac arrest, flushed via the portal vein with 20 mL of heparinized Ringer's solution and 60 mL of histidine-tryptophan-ketoglutarate (HTK) preservation solution. Control livers were then stored submerged in HTK for 24 h at 4 degrees C while other organs were subjected to aerobic conditions by either insufflation of gaseous oxygen via the venous vascular system of the cold stored organ (VSOP) or pulsatile machine perfusion (MP) with oxygenated HTK at 5 mL/min at 4 degrees C. Superoxide dismutase (SOD) (7500 IU) was added to the last 10 mL of HTK in order to prevent adverse effects of high oxygen tensions at hypothermia. Viability of the livers was assessed upon isolated perfusion in vitro with oxygenated Krebs-Henseleit buffer at constant flow. VSOP or MP, both significantly improved vascular conductivity upon reperfusion as evaluated by portal venous pressure, reduced hepatic enzyme release and led to a rise in hepatic bile production upon reperfusion. Induction of apoptosis was also looked for in tissue homogenates by Western analysis for cleavage of poly(ADP-ribose)polymerase (PARP). Expression of cleaved PARP fragment could be found in reperfused control livers but also, though to a lesser extend, after VSOP or MP. In conclusion, provision of oxygen during cold preservation significantly contributes to improve organ viability upon reperfusion and must be regarded as a useful adjunct for marginal or pre-damaged livers. HTK has been shown for the first time to be also suitable for long-term MP preservation of the liver, but, as inferred from these data, simple insufflation of gaseous O2 may be considered a feasible alternative.  相似文献   
76.
Introduction Postoperative treatment for colorectal cancer depends on tumor stage as defined by the International Union Against Cancer (UICC). Adjuvant chemotherapy is not recommended in patients without lymph node involvement (UICC stages I and II). As many as 20–30% of these patients, however, will develop recurrence. Aims and objectives We conducted this study to determine the presence of disseminated tumor cells in the lymph nodes by quantitative real-time polymerase chain reaction (QRT-PCR) for cytokeratin 20 (CK20) in an attempt to provide supplementary information compared to histopathological findings. Materials and methods Using a standard QRT-PCR assay, we examined primary tumors and 391 lymph nodes from 31 patients with completely resected colorectal cancer. Results Of the 31 primary tumors, 29 were positive for CK20 by QRT-PCR. Discussion An examination of the lymph nodes from the 29 patients with CK20-positive primary tumors revealed that 35 (92.1% sensitivity) of the 38 histopathologically positive lymph nodes and 54 (16.7%) of the 324 histopathologically negative lymph nodes were positive by molecular analysis. CK20 expression was detected in 10 (100%) of 10 patients with a histopathologically positive lymph node status (pN1). In 9 (47.4%) of 19 patients with negative histopathological results (pN0), we detected a CK20 mRNA signal in at least one lymph node. Whereas eight patients with histopathologically negative lymph nodes could be upstaged on the basis of the molecular findings, no patient would be downstaged. Conclusion Our results suggest that QRT-PCR for CK20 is a useful tool for the quantitative detection of micrometastases in the regional lymph nodes. We introduce a standardized procedure that integrates a molecular diagnostic technique in the clinical staging.  相似文献   
77.
Nociceptive primary afferent neurons carry nicotinic acetylcholine receptors (nAChRs). Using RTPCR, mRNAs for all alpha-subunits have been identified in rat dorsal root ganglia (DRG) (Genzen et al., 2001; Lips et al., 2002), but the responses of nociceptive neurons to nicotine are not uniform and the cellular distribution of nAChRs within DRG, in general, and among functionally different subtypes of primary afferent neurons, in particular, are only partially resolved (Rau et al., 2005). These diverse actions might suggest the presence of various nAChR isoforms that are operative under different conditions. The present study was aimed to extend previous studies on nAChRs that contain subunits alpha4, alpha7, and alpha10 in providing data for alpha3- and alpha5-subunit-containing nAChRs (Haberberger et al., 2004; Papadopolou et al., 2004). To this end, calcium-imaging and double-labeling immunofluorescence with nAChR alpha-subunit-specific antibodies, in combination with markers for nociceptive neurons (TRPV1, I-B4), were applied.  相似文献   
78.
Nonmotor symptoms (NMS) of Parkinson's disease (PD) are not well recognized in clinical practice, either in primary or in secondary care, and are frequently missed during routine consultations. There is no single instrument (questionnaire or scale) that enables a comprehensive assessment of the range of NMS in PD both for the identification of problems and for the measurement of outcome. Against this background, a multidisciplinary group of experts, including patient group representatives, has developed an NMS screening questionnaire comprising 30 items. This instrument does not provide an overall score of disability and is not a graded or rating instrument. Instead, it is a screening tool designed to draw attention to the presence of NMS and initiate further investigation. In this article, we present the results from an international pilot study assessing feasibility, validity, and acceptability of a nonmotor questionnaire (NMSQuest). Data from 123 PD patients and 96 controls were analyzed. NMS were highly significantly more prevalent in PD compared to controls (PD NMS, median = 9.0, mean = 9.5 vs. control NMS, median = 5.5, mean = 4.0; Mann-Whitney, Kruskal-Wallis, and t test, P < 0.0001), with PD patients reporting at least 10 different NMS on average per patient. In PD, NMS were highly significantly more prevalent across all disease stages and the number of symptoms correlated significantly with advancing disease and duration of disease. Furthermore, frequently, problems such as diplopia, dribbling, apathy, blues, taste and smell problems were never previously disclosed to the health professionals.  相似文献   
79.
In contrast to the controversy regarding the terminology and behavior of ovarian noninvasive low-grade serous tumors [atypical proliferative serous tumor (APST) and serous borderline tumor], little attention has been directed to their origin. Similarly, until recently, proliferative lesions in the fallopian tube had not been extensively studied. The recent proposal that ovarian high-grade serous carcinomas are derived from intraepithelial carcinoma in the fallopian tube prompted us to evaluate the possible role of fallopian tube in the genesis of low-grade serous tumors. We have identified a lesion, designated "papillary tubal hyperplasia (PTH)," characterized by small rounded clusters of tubal epithelial cells and small papillae, with or without associated psammoma bodies, that are present within the tubal lumen and which are frequently associated with APSTs. Twenty-two cases in this study were selected from a population-based study in Denmark of approximately 1000 patients with low-grade ovarian serous tumors in whom implants were identified on the fallopian tube. Seven additional cases were seen recently in consultation at The Johns Hopkins Hospital (JHH). These 7 cases were not associated with an ovarian tumor. PTH was found in 20 (91%) of the 22 cases in the Danish study. On the basis of this association of PTH with APSTs with implants and the close morphologic resemblance of PTH, not only to primary ovarian APSTs but also to noninvasive epithelial implants and endosalpingiosis, we speculate that the small papillae and clusters of cells from the fallopian tube implant on ovarian and peritoneal surfaces to produce these lesions. The 7 JHH cases of PTH that were not associated with an ovarian tumor support the view that PTH is the likely precursor lesion. We propose a model for the development of ovarian and extraovarian low-grade serous proliferations (APST, noninvasive epithelial implants, and endosalpingiosis) that postulates that all of these lesions are derived from PTH, which appears to be induced by chronic inflammation. If this hypothesis is confirmed, it can be concluded that low-grade and high-grade ovarian tumors develop from tubal epithelium and involve the ovary secondarily.  相似文献   
80.
OBJECTIVE: We investigated outcomes after surgical therapy in patients with active infective endocarditis (AIE) with regard to survival in relation to surgical urgency, valve position, number of valves implanted and abscess formation. We aimed to identify independent risk factors for early mortality. METHODS AND RESULTS: Two hundred and fifty-five patients received Shelhigh bioprostheses between February 2000 and March 2007. A total of 74.1% had native and 25.9% prosthetic AIE. Surgery was regarded as urgent in 57.3% and as an emergency procedure in 38.4%. There was a highly significant difference in survival rate between patients who were operated on urgently versus in an emergency (p<0.0001), between single and double valve replacement (p=0.0206) and between patients with and without abscess formation (p=0.0245). There were two cases of early reinfection (0.78%) and six of late reinfection (2.35%) leading to re-operation. CONCLUSIONS: The survival of patients differs significantly in dependence on their surgical urgency. Better outcome could have been achieved if patients had been referred earlier for surgery and operated upon before heart failure or septic shock developed. Long-term survival was better in patients without abscess formation. The low reinfection rate of Shelhigh bioprostheses in AIE is promising and the early and mid-term results achieved need to be verified in the long-term course.  相似文献   
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