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1.
The effects of two promoters of hepatocarcinogenesis--phenobarbital and butylated hydroxytoluene (BHT)--on five hepatic biochemical parameters were examined in adult female rats. Phenobarbital given orally in two doses each of 110 mg/kg 21 and 4 hr before the rats were killed caused large increases in hepatic ornithine decarboxylase (ODC) activity and cytochrome P-450 content. Extending the number of phenobarbital treatments to five increased the hepatic enzyme induction and also caused a minor decrease in hepatic glutathione and a small increase in serum alanine aminotransferase activity. Two oral doses of 700 mg BHT/kg (20% of the LD50) caused hepatic DNA damage and induction of both ODC activity and cytochrome P-450 content. When the dose of BHT was reduced from 700 to 140 mg/kg no significant effects on the biochemical parameters were found. Both promoters of hepatocarcinogenesis were identified by their induction of ODC, a marker for promotional potential, but only BHT showed a potential for carcinogenic initiation. The biochemical parameters examined, particularly the alkaline elution technique for DNA damage, ornithine decarboxylase activity and serum alanine aminotransferase, may constitute a useful assay system for examining a compound's potential for carcinogenic initiation, carcinogenic promotion and cellular toxicity. 相似文献
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The role of size, sequence and haplotype in the stability of FRAXA and FRAXE alleles during transmission 总被引:2,自引:5,他引:2
Murray A; Macpherson JN; Pound MC; Sharrock A; Youings SA; Dennis NR; McKechnie N; Linehan P; Morton NE; Jacobs PA 《Human molecular genetics》1997,6(2):173-184
Factors involved in the stability of trinucleotide repeats during
transmission were studied in 139 families in which a full mutation,
premutation or intermediate allele at either FRAXA or FRAXE was
segregating. The transmission of alleles at FRAXA, FRAXE and four
microsatellite loci were recorded for all individuals. Instability within
the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for
FRAXE) was extremely rare; only one example was observed, an increased in
size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in
the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were
unstably transmitted. Instability was more frequent for FRAXA intermediate
alleles that had a tract of pure CGG greater than 37 although instability
only occurred in two of 13 such transmissions: the changes observed were
limited to only one or two repeats. Premutation FRAXA alleles over 100
repeats expanded to a full mutation during female transmission in 100% of
cases, in agreement with other published series. There was no clear
correlation between haplotype and probability of expansion of FRAXA
premutations. Instability at FRAXA or FRAXE was more often observed in
conjunction with a second instability at an independent locus suggesting
genomic instability as a possible mechanism by which at least some FRAXA
and FRAXE mutations arise.
相似文献
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S-A Ivarsson D Bergqvist NR Lundström E Maly KO Nilsson C Wattsgård 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(12):1044-1048
We report a case of Takayasu's disease with severe renovascular hypertension in a girl from Eritrea. In the "burn-out" phase after the erythrocyte sedimentation rate had normalized, reconstructive vascular surgery was performed as further progression of the disease seemed unlikely. However, probably due to her growth, the graft rotated and a second operation was successfully performed. 相似文献
6.
Inpatient dependency in activities of daily living predicts informal caregiver strain: A cross‐sectional study
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Effects of sustained isometric handgrip on praecordial accelerocardiogram in normal subjects and in patients with heart disease.
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The effects of isometric exercise on the maximum amplitude of the praecordial accelerocardiogram (as represented by the DE deflection) have been compared in 6 normal subjects (group 1), 12 patients with aortic stenosis (group 2), and 16 patients with myocardial disease (group 3). Whereas the tachycardia and pressor effects of isometric exercise were identical in all three groups, the normal subjects showed a significant decrease in DE during handgrip of 10 +/- 4 per cent (P less than 0.05) as compared with the insignificant increases of 8.5 +/- 6 per cent (P greater than 0.5), and 4 +/- 3.5 per cent (P greater 0.3) observed in the patients in groups 2 and 3. This response in the normal subjects differed significantly from the responses observed in the patients in groups 2 (P less than 0.02) and 3 (P less than 0.01). Of the patients in each of groups 2 and 3, 50 per cent responded abnormally to handgrip in that they showed a significant increase in DE. In the patients with aortic stenosis this subgroup of patients differed from the remainder in that they had a higher resting cardiac index (P less than 0.05). In the patients with myocardial disease this subgroup was characterized by a significantly lower resting left ventricular end-diastolic pressure (P less than 0.02). It seems, therefore, that those patients who increase DE in response to handgrip tend to have better left ventricular function at rest than those who do not. We suggest that this may be because of increased beta adrenergic activity at rest and during isometric exercise in the subgroup who respond to handgrip with an increase in DE. 相似文献