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81.
Tissue-factor coagulant activity of cultured human endothelial and smooth muscle cells and fibroblasts 总被引:24,自引:1,他引:24
The tissue-factor (thromboplastic) activity of cultured human endothelial cells and fibroblasts is low at time of transfer into fresh medium but increases 3-10 fold. Endothelial cells reach peak activity (400 U/10(5) cells) 5-8 hr after subculture. Activity in fibroblast cultures peaks (3000-12,000 U/10(5) cells) 7-12 hr after subculture. After attaining maximum activity, endothelial and fibroblast tissue- factor content decreases in a time course similar to other cells studied in this laboratory, approaching basal levels by 24-50 hr after subculture. If medium over fibroblasts is changed every 12 hr, activity can be sustained at the peak level for an additional day but cannot be maintained at a high level indefinitely. The kinetics of expression of smooth muscle cell tissue factor are markedly different from other cell types. There is always a pronounced lag (30 hr or more) before the activity increases, and then, in most cases, there is no subsequent decline in activity even though the cells are not refed or restimulated. The activity of each of these cell types is cryptic but becomes available after freeze-thaw disruption of cells. 相似文献
82.
Peter J Vento Meghan E Swartz Lisa BE Martin Derek Daniels 《Journal of the American Association for Laboratory Animal Science》2008,47(6):46-50
The benzimidazole anthelmintic fenbendazole (FBZ) is a common and effective treatment for pinworm infestation in laboratory animal colonies. Although many investigators have examined the potential for deleterious biologic effects of FBZ, more subtle aspects of the treatment remain untested. Accordingly, we evaluated differences in food intake when healthy male Sprague–Dawley rats were provided a standard nonmedicated laboratory rodent chow or the same chow supplemented with FBZ. We also tested for a preference for either food type when subjects were provided a choice of the 2 diets. Data from these experiments showed no differences in food intake or body weight when rats were maintained on either standard or FBZ-supplemented chow. When the rats were given access to both the standard and FBZ-supplemented diets, they showed a clear preference for the standard diet. The preference for the standard diet indicates that the rats can discriminate between the 2 foods and may avoid the FBZ-supplemented chow when possible. Investigators conducting experiments during treatment with FBZ in which differences in food preference are relevant should be aware of these data and plan their studies accordingly.Abbreviation: FBZ, fenbendazolePinworm infestation is a common and troublesome situation that can arise in the maintenance and care of laboratory rat colonies.8,9 A popular and effective treatment strategy relies on a diet that has been supplemented with the benzimidazole anthelmintic fenbendazole (FBZ; methyl 5-[phenylthio]-2-bendzimidazole carbamate).4,6,7 According to a 1991 toxicology evaluation released by the World Health Organization, therapeutic levels of fenbendazole can be administered throughout the lifetime in rodents without significant toxic side effects.11 Moreover, previous experiments have failed to find carcinogenic effects of FBZ treatment at therapeutic doses (for review, see reference 20). However, various histological changes, such as hepatocellular hypertrophy and bile duct proliferation and hyperplasia, have been reported to occur in dosages exceeding 45 mg/kg.11,22 In addition, rats maintained on a diet containing FBZ had smaller litter sizes than those on an unmedicated diet.10 Nevertheless, deleterious effects resulting from therapeutic doses of FBZ appear to be minimal.Therapeutic doses of FBZ have few, if any, behavioral effects. One study1 found that when FBZ was administered to female rats throughout pregnancy and gestation, the pups showed no deficits in digging maze performance and negative geotaxis, whereas the pregnant dams showed no difference in drinking or weight gain. However, the progeny of the FBZ-treated dams showed decreased performance in running-wheel and Morris water maze tests and demonstrated delayed righting reflex.1 Nevertheless, adult rats treated with FBZ failed to differ from controls in a variety of tests, including conditioning and timing tasks that are sensitive to neurotoxic drug effects.12Although the potential for deleterious effects of FBZ has garnered much interest, more subtle issues remain untested. Diet and taste preference are important factors that may affect many types of experiments, especially those measuring food intake. To address the paucity of information related to intake of FBZ-supplemented food, we measured food intake and weight gain in healthy rats given standard or FBZ-supplemented chow. We also tested for a preference between standard and FBZ-supplemented diets. The data from these experiments indicate that rats consumed normal levels of the medicated diet when it was the only food available and did not alter their intake when switched from standard to FBZ-supplemented chow (or vice versa). Nevertheless, the rats showed a strong preference for the nonmedicated diet when given a choice. 相似文献
83.
84.
Yoshiya Kawamura BE MD Yukie Takahashi RN PHN Tsuyoshi Akiyama MD PhD Tsukasa Sasaki MD PhD Masako Kako RN MSN 《Asia-Pacific psychiatry》2009,1(3):138-142
Introduction: The present study examined the reliability, validity, and cutoff scores of the Japanese version of the Child Abuse Potential Inventory (CAPI) abuse scale, which screens for parents at risk of child abuse. Methods: Samples consisted of 1,809 parents, 109 students, and 33 child abusers in Japan. The CAPI was administered to all participants, and twice to the student sample at a 2‐week interval. Internal consistency was evaluated by Cronbach's α, and construct validity by principal factor analysis with the parent sample. Test‐retest reliability was assessed with Pearson's r with the student sample. With regard to predictive validity, the cutoff scores and classification rates were calculated through discriminant analysis between abusers and matched non‐abusers. Results: Internal consistency (Cronbach's α=0.88), test‐retest reliability (Pearson's r=0.93; two‐tailed P<0.001), and predictive validity (overall diagnostic power=90%) were all highly satisfactory. Regarding construct validity, the six‐factor structure of the original version was not replicated; only three factors were obtained. The discriminant analysis showed the basic cutoff score as 159. The conservative cutoff score for the upper 5% of the parent sample was 218. Discussion: The Japanese version of the CAPI abuse scale showed highly satisfactory internal consistency, test‐retest reliability, and predictive validity. The construct correspondence with the original version was more compromised. This version of the CAPI identified parents with scores of 159 or greater as being at risk of abusing a child. 相似文献
85.
86.
Calprotectin is an abundant neutrophil cytosolic protein released during neutrophil activation or death. The use of plasma calprotectin concentration as a marker of pulmonary inflammation was tested in 31 children with cystic fibrosis, none of whom was acutely unwell or pyrexic. Twenty three were receiving antibiotics, 21 had positive sputum cultures, but none of the traditional tests clearly diagnosed ongoing infection. Plasma calprotectin was significantly higher in the cystic fibrosis group than in matched controls. Sixteen children with cystic fibrosis had values above the control range (320-1570 micrograms/l). Their chest radiograph Northern score, an index of accumulated pulmonary involvement, and their plasma copper, an index of acute phase response, both correlated with plasma calprotectin. Plasma gamma-glutamyltransferase also correlated weakly with plasma calprotectin: thus, hepatic pathology may be a confounding variable. However, the data still suggested that plasma calprotectin is a better index of inflammation than the traditional indices in general use. 相似文献
87.
Patients with severe thalassaemia major suffer endocrine and other abnormalities before their eventual death from iron overload due to repeated blood transfusions. The endocrine status of 31 thalassaemic patients aged 2-5 to 23 years was investigated. Exact data were available on the rate and duration of blood transfusion in all of them and in many the liver iron concentration was also known. Although the patients were euthyroid, the mean serum thyroxine level was significantly lower, and the mean thyrotrophic hormone level significantly higher, compared with the values found in normal children. Forty oral glucose tolerance tests with simultaneous insulin levels were performed in 19 children, of whom 5 developed symptomatic diabetes and one had impaired tolerance. Previous tests on all 6 patients were available and some showed raised insulin levels possibly due to insulin resistance. 2 patients had clinical hypoparathyroidism and are described. The parathyroid hormone levels determined by radioimmunoassay in 25 patients were below the mean for the age group in all and outside the reference range in 16. Nonfasting plasma calcium levels were not reduced. Puberty was delayed in some patients. Concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) measured in urine from 7 girls and 5 boys showed considerable variation. In the boys there was an overall tendency for FSH and LH excretion to be low with regard to age, but with respect to puberty rating FSH exretions were normal or low and LH normal or raised. The girls showed a tendency for LH but not FSH excretion to be raised in relation to puberty rating. The severity of the endocrine changes was related to the degree of iron loading and is discussed in relation to previous work in which the iron loading has rarely been accurately indicated nor parathyroid status assessed. 相似文献
88.
89.
90.
It has been reported that chloroform administered to BDF1 mice by
inhalation for 2 years at concentrations of 5, 30 or 90 p.p.m. for 6 h/day,
5 days/week induced an increase in renal cell tumors in male but not female
mice exposed to the doses of 30 and 90 p.p.m. A small increase in liver
tumors was statistically significant in the female mice at 90 p.p.m. if the
incidences of carcinomas and adenomas were combined. Because chloroform is
not a DNA reactive mutagen, a 13-week time-course and dose-response study
was conducted under conditions of the original bioassay to examine whether
regenerative cell proliferation was an underlying mechanism of
carcinogenesis. Mice were given bromodeoxyuridine via infusion during the
last 3.5 days prior to necropsy to label cells in S-phase. Chloroform
induced pathology and regenerative cell proliferation, measured as the
labeling index (LI, percentage of cells in S-phase), were assessed
microscopically and immunohistochemically. Male mice exposed to 30 and 90
p.p.m. exhibited a dose-dependent increase in regenerating tubules within
the renal cortex and up to a 31-fold increase in LI. No renal lesions or
increased LI were observed in females. Increased centrilobular to midzonal
hepatocyte degeneration and vacuolation and a 7-fold increase over controls
in the hepatocyte LI were observed in the female mice at 90 p.p.m. at 13
weeks. Males exhibited similar pathology, but the increase in LI was not
sustained. The observed correlations between cytolethality and regenerative
cell proliferation with tumor formation supports extensive evidence that
chloroform induces cancer via a non- genotoxic-cytotoxic mode of action. A
concentration of 5 p.p.m. is the no-observed-adverse-effect level for
nephrotoxicity, cell proliferation and cancer. An appropriate safety factor
applied to this value is a straightforward approach to cancer risk
assessment that is consistent with the mode of action of chloroform.
相似文献