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51.
Xi  L; Zhang  L; Wang  Y; Smith  MT 《Carcinogenesis》1997,18(9):1687-1693
1,3-Butadiene is a carcinogen in rodents, but its potential carcinogenicity to humans remains controversial. Numerous studies have shown that butadiene and its metabolites cause sister chromatid exchanges in vitro and in vivo. To test for other types of genotoxicity, the micronucleus assay and fluorescence in situ hybridization (FISH) have been used to detect chromosome damage in human lymphocytes caused by two reactive metabolites of butadiene, diepoxybutane (DEB) and monoepoxybutene (MEB). DEB (0.5-5.0 microM) significantly increased micronucleus formation 4- to 6-fold (P <0.01) and MEB (1-500 microM) by 2- to 4-fold (P <0.01) over control levels. The ability of DEB and MEB to induce aneuploidy of chromosomes 7, 8, 12, and X was examined using dual-color FISH in both interphase and metaphase cells. These chromosomes were chosen because of their involvement in leukemogenesis. Both DEB and MEB caused dose-dependent increases in hyperdiploidy of chromosomes 12 and X, but had no discernible effect on chromosomes 7 and 8. These results suggest that DEB and MEB cause chromosome-specific aneuploidy in human cells. If formed in sufficient amounts, DEB and MEB may produce chromosome damage of the type found in leukemia following exposure to butadiene.   相似文献   
52.
Six children presenting with partial growth hormone (GH) deficiency (mean GH peak in two different tests, 8.0 k1.3 μ g/l ) aged 8–10.3 years (mean, 2.7 ± 0.9 years) were treated for 6 months by continuous subcutaneous infusion of GH-releasing hormone(1–29)-NH, (GHRH(1–29)-NH2); 24-hour GH profiles and height velocity were measured. A biphasic effect of GHRH(1–29)-NH2 infusion was observed. After an early substantial increase in the 24-hour integrated concentration of GH, from 1.6 ± 0.1 to 3.5 ± 0.7 μg/l/minute, a subsequent consistent decrease occurred by 3 months, which was more pronounced after 6 months (mean 24-hour integrated concentration of GH, 1.9± 0.9 μg/l/minute). This effect reflects modification of both pulse amplitude and frequency of GH secretion. At the end of the study, one child had complete suppression of GH secretion and two others showed only one peak above 5 μg/1 during a 24-hour period. No correlation was found between these changes and height velocity. Three children did not grow significantly; the other three children who had a growth response to GHRH(1–29)-NH2 were those with the lowest 24-hour integrated GH concentration at the end of the study. The possible mechanisms involved in this biphasic effect, including GHRH antibodies, changes in somatostatin levels and/or desensitization of pituitary GHRH receptors, have been investigated.  相似文献   
53.
Moderate and severe malnutrition are endemic in much of the developing world and in association with pockets of deprivation in the developed world. The cost in terms of individual and social development is high. The principles of effective management are clearly documented. A low cost, community based treatment programme for moderately and severely malnourished children under 3 years of age was established at a health centre in rural Jamaica. Children were followed up monthly and defaulters were rigorously recalled. Management consisted of carefully delivered dietary advice, antibiotics, anthelminthics, and vitamin supplements. All children improved and the response of 36 children, who were treated in the first year, showed an accelerated weight gain, with catch-up growth and the maintenance of length gain. There was a significant increase in the weight for age, at 1.9% per month over six months, which exceeds the rate reported with food supplementation programmes and nutrition rehabilitation centres.  相似文献   
54.
The use of follow up studies was evaluated in 128 patients with coeliac disease during their first visit to a department for adults. The original diagnosis had been made in childhood in all patients. Fifty eight (45%) of the subjects were following a gluten free diet, 23 (18%) were following a gluten free diet but with occasional gluten consumption, and 47 (37%) had adopted an unrestricted, gluten containing diet for a mean of 11.2 years. There was no correlation in individual subjects between the presence of symptoms, biochemical and immunological abnormalities, severity of histological findings, and the amount of dietary gluten, despite the greater frequency of symptoms in the group following an unrestricted diet than in the other two groups. Short stature and epilepsy with cerebral calcifications only occurred in patients following an unrestricted diet. As only diagnosis based on two or three biopsy samples and regular follow up correlated positively with dietary compliance, it is suggested that a histologically confirmed diagnosis of coeliac disease and regular lifelong follow up are essential in the management of these patients.  相似文献   
55.
Wooden foreign bodies in soft tissue: detection at US   总被引:4,自引:0,他引:4  
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The clinical study of treated subjects and nontreated controls was made in healthy eumenorrheic young postadolescent women volunteers in the Department of Obstetrics and Gynaecology at Cagliari University, to investigate whether an oral contraceptive (OC) containing drospirenone (3 mg) plus ethinyl estradiol (30 microg) (DRSP+EE) can affect bone metabolism. Control group (n = 26) and OC group (n = 28) women did not differ in age, body mass index, waist-to-hip ratio and main outcome measures [urinary levels of deoxypyridinoline and pyridinoline, serum levels of osteocalcin, bone specific alkaline phosphatase (bSAP), total testosterone (total-T), sex hormone-binding globulin (SHBG), progesterone and bone mineral density (BMD) at the heel]. The control group was studied at the luteal phase (LP) during both the first and the sixth menstrual cycle; the OC group was studied during the first cycle at the LP, and on days 16-18 of the sixth cycle of DRSP+EE treatment. At the sixth cycle, in the control group, the main outcome measures did not change compared to baseline. In the OC group, deoxypyridinoline, pyridinoline, osteocalcin, bSAP, total-T and progesterone levels were reduced, whereas SHBG levels were increased. The BMD was unchanged compared to baseline. The results suggest that 6-month DRSP+EE treatment decreases bone turnover.  相似文献   
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