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61.
Gerbils are much more sensitive to the hepatotoxic and lethal effects of CCl4 than rats as indicated by 48-hr LD50 values (0.08 vs 2.8 ml/kg). On the other hand, gerbils are refractory to chlordecone (CD) potentiation of CCl4 toxicity. To investigate the possible mechanism underlying the high sensitivity of gerbils to CCl4 lethality, the metabolism of CCl4 was studied in gerbils pretreated with dietary CD, phenobarbital (PB), or mirex (M) at 10, 225, and 10 ppm, respectively. The hepatic content of 14CCl4, the expiration of 14CCl4 and 14CCl4-derived 14CO2, and lipid peroxidation were measured and the results were compared with the previous data for rats. After the 15-day dietary pretreatment, male gerbils (60-80 g) received 14CCl4 (0.08 ml/kg; sp act 0.04 mCi/mmol) ip in corn oil and the radioactivity present in the expired air was collected for 6 hr. More than 80% of the parent compound as represented by the 14C-label in the toluene trap was expired in 6 hr regardless of the pretreatments. Expiration of 14CO2 measured during the 6 hr after 14CCl4 administration in control gerbils was 3.5-fold more than that in rats and was significantly increased in pretreated groups (M greater than PB greater than CD). PB and M pretreatments resulted in a significant increase of 14C-label bound to the nonlipid fraction of the liver as compared with CD-treated or control gerbils. The radiolabel present in the livers of control gerbils was 5-fold higher than that of rats. In vivo lipid peroxidation measured as diene conjugation in lipid extracts from the livers was lower in gerbils than in rats, and none of the pretreatments significantly affected lipid peroxidation. The serum alanine aminotransferase and aspartate aminotransferase were significantly elevated at 6 hr after CCl4 injection in all groups of gerbils. These data indicate that the more extensive metabolism of CCl4, as represented by 14CO2 formation and 14C-label bound to hepatic tissue, in gerbils as compared with rats, may partially explain the high sensitivity of gerbils to CCl4 toxicity. However, the enhanced metabolism of CCl4 found in CD-, PB-, or M-pretreated gerbils did not lead to amplified hepatotoxic and lethal effects of CCl4. The reason gerbils may be refractory to CD amplification of CCl4 injury might be associated with other factors yet to be investigated. 相似文献
62.
实验国际学校学生膳食及营养状况的调查 总被引:2,自引:0,他引:2
本文对南京实验国际学校369名6~11岁学生进行了膳食及营养状况的分析研究。结果表明:该校学生膳食中除视黄醇、钙及锌(9~11岁组)不足外,其余营养素和热能均超过推荐供应量。蛋白质量足质优。脂肪在一天总热能中比例较高.达到30%左右。该校学生营养过剩发生率达18.4%.提示该校食堂要注意学生膳食的合理调配.防止学生摄入过多脂肪和热能;同时建议增加含钙、锌高的食物供给,以补充其不足。 相似文献
63.
乡(镇)卫生院是农村三级医疗预防保健网的中心环节,是我国农村实现“2000年人人享有卫生保健”的关键。本文通过对广东省梅县乡(镇)一级卫生院卫生人力状况的调查分析,结果表明,目前该县乡镇卫生院的机构稳定,卫技人员占编比例合理,年龄较轻,成为今后农村卫生院发展的优势。但存在着卫生技术人员的总体数量不足,素质较差,各类专业技术人员的构成比例失调和层次分布不合理等问题,同时提出了如何加以改善的对策措施。 相似文献
64.
Evidence that [3H]-alpha,beta-methylene ATP may label an endothelial-derived cell line 5'-nucleotidase with high affinity. 总被引:1,自引:1,他引:0 下载免费PDF全文
A. D. Michel N. M. Chau T. P. Fan E. E. Frost P. P. Humphrey 《British journal of pharmacology》1995,115(5):767-774
1. In membranes prepared from a permanent cell line of endothelial origin (WEC cells), [3H]-alpha, beta-methylene ATP ([3H]-alpha, beta-meATP) labelled high (pKd = 9.5; Bmax = 3.75 pmol mg-1 protein) and low (pKd = 7.2; Bmax = 23.3 pmol mg-1 protein) affinity binding sites. The high affinity [3H]-alpha, beta-meATP binding sites in the WEC cell membranes could be selectively labelled with a low concentration of the radioligand (1 nM). In competition studies performed at a radioligand concentration of 1 nM, 88.6% of the sites possessed high affinity (pIC50 = 8.26) for alpha, beta-meATP. 2. The high affinity [3H]-alpha, beta-meATP binding sites appeared heterogeneous since in competition studies a number of nucleotide analogues (alpha, beta-meADP, ATP, ADP, AMP, GTP, GppNHp, GMP) and adenosine identified two populations of the sites labelled by 1 nM [3H]-alpha, beta-meATP. The proportion of sites with high affinity for these compounds was found to vary between 42 and 69%. 3. Approximately 60-69% of the binding sites labelled with 1 nM [3H]-alpha, beta-meATP possessed high affinity for alpha, beta-meADP (pIC50 = 8.87), AMP (pIC50 = 7.12), GMP (pIC50 = 7.34), UTP (pIC50 = 6.12), GTP (pIC50 = 7.59), GppNHp (pIC50 = 7.35) and adenosine (pIC50 = 5.45).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
65.
本研究采用先进的三维超声成像技术及多普勒技术对正常育龄妇女月经周期中心血管功能进行研究。结果:月经周期中HR、BP无变化;血清E2是周期性变化,排卵前达高峰。SV、CO、EF在排卵前期升高达峰值,显著高于月经期和黄体期;SVR排卵前期最低,而Ved、Ves无变化。Vmax、A、E在内源性E2高峰时明显加快,而E/A比值无明显变化。结果提示:月经周期中随内源性E2的周期性变化,心脏功能也发生周期性变化。E2高峰时,心输出量、心搏量和射血分数达最高。外周阻力最低,心脏内血流速度加快。 相似文献
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OBJECTIVE: To study the value of serum progesterone in selecting the candidate patients with ectopic pregnancy (EP) for methotrexate (MTX) treatment and in monitoring the effect of the treatment. METHODS: Thirty-seven EP patients who were given single-dose intramuscular injection with 50 mg/m2 MTX were divided into success and failure groups according to the effect of the treatment. The serum progesterone concentrations in these patients were measured and compared between the 2 groups, and the receiver-operator curves (ROC) were used to determine the critical serum progesterone levels for assessing the effect of MTX treatment. The time consumed respectively by serum progesterone and beta-human chorionic gonadotrophin (beta-hCG) decreasing to below normal level was also compared. RESULTS: The serum progesterone concentrations of the success group (7.93+/-2.02 ng/ml) were significantly lower than those of the failure group (14.53+/-1.72 ng/ml, P<0.05). The recommended critical level for assessing the effect of MTX treatment for EP patients was 11 ng/ml according to the ROC, and the time for serum progesterone decreasing to below normal level was significantly less than that for beta-hCG. CONCLUSION: Serum progesterone can be used as an index for selecting candidate EP patients for MTX treatment, and also as a good indicator for assessing the therapeutic effect after treatment. 相似文献