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排序方式: 共有974条查询结果,搜索用时 15 毫秒
931.
932.
933.
Oxidative stress and antioxidant status in beta-thalassemia major: iron overload and depletion of lipid-soluble antioxidants 总被引:4,自引:0,他引:4
Livrea MA; Tesoriere L; Pintaudi AM; Calabrese A; Maggio A; Freisleben HJ; D'Arpa D; D'Anna R; Bongiorno A 《Blood》1996,88(9):3608-3614
Because of continuous blood transfusions, thalassemia patients are subjected to peroxidative tissue injury by the secondary iron overload. In accordance, analysis of serum from 42 beta-thalassemia patients, aged 4 to 40 years, showed that the mean concentrations of conjugated diene lipid hydroperoxides (CD), lipoperoxides evaluated as malondialdehyde/ thiobarbituric acid (MDA/TBA) adducts, and protein carbonyls increased about twofold with respect to control. Ferritin levels were positively correlated with the amount of MDA (r = .41; P = .007) and showed a positive trend with CD (r = .31; P = .07) and protein carbonyls (r = .35; P = .054), as further evidence of the deleterious effects of high tissue iron levels. Marked changes in the antioxidant pattern were also observed in all patients. Evidence is presented of a net drop in the concentration of ascorbate (-44%), vitamin E (-42%), vitamin A(-44%), beta-carotene (-29%), and lycopene (- 67%). On the other hand, an increase of uric acid and bilirubin was observed, whereas serum albumin and glutathione were in the normal range in all patients. As a result, the total serum antioxidant potential, measured as trolox equivalent antioxidant capacity appeared significantly decreased by 14%. Serum levels of vitamin E were inversely correlated with ferritin (r = -.45; P = .003), suggesting a major consumption of this antioxidant under iron overload. Nontransferrin bound iron (NTBI) was in the range 4.5 to 54.8 micrograms/dL (mean, 21.8 +/- 13.9). Although NTBI had a positive trend with ferritin (r = .37, P = .03), no clear correlation was found with either MDA or vitamin E. A mild to severe hepatic damage, as assessed by serum transaminases, was shown in 24 of 42 patients. Serum levels of vitamin E (r = -.49, P = .015), vitamin A (r = -.48, P = .016) and lycopene (r = -.47, P = .020), were inversely correlated with the levels of transminases. On the other hand, lipid-soluble antioxidants in thalassemia patients were depleted to the same extent in hepatitis C virus (HCV)-infected (31 subjects) and in HCV-uninfected (10 subjects), while in the normal range in serum from 30 nonthalassemic patients with HCV-related chronic hepatitis. These results point out that the iron- induced liver damage in thalassemia may play a major role in the depletion of lipid-soluble antioxidants. The variations of the parameters evaluated in the present study were not correlated with the age of the patients. Our results suggest that the measurement of peroxidation products, matched with evaluation of antioxidants, may be a simple measure of iron toxicity in thalessemia, in addition to the conventional indices of iron status. 相似文献
934.
935.
Roozenburg BJ; van Dessel HJ; Evers JL; Bots RS 《Human reproduction (Oxford, England)》1997,12(8):1720-1722
Patients suffering from normogonadotrophic anovulation and infertility are
initially treated with clomiphene citrate. Those who do not respond to
clomiphene citrate usually receive gonadotrophin treatment which is
labour-intensive, expensive, and associated with an increased risk of
multiple pregnancies and ovarian hyperstimulation syndrome. We treated 22
patients with clomiphene resistant normogonadotrophic anovulation with
naltrexone (an opioid receptor blocker) alone or naltrexone in combination
with an antioestrogen. In 19 patients ovulation and resumption of a regular
menstrual cycle was achieved and in 12 out of 19 a singleton pregnancy was
observed. In conclusion, ovulation can be induced successfully using
naltrexone alone or naltrexone in combination with an anti-oestrogen in
clomiphene citrate resistant anovulatory patients. Compared to
gonadotrophin induction of ovulation, this method is safe, simple and
inexpensive.
相似文献
936.
Suspected recurrent rectosigmoid carcinoma after abdominoperineal resection: MR imaging and histopathologic findings 总被引:17,自引:1,他引:16
Eleven patients who underwent abdominoperineal resection for rectosigmoid carcinoma were examined with magnetic resonance (MR) imaging for suspected recurrent tumor in the presacral space. There were 12 suspected masses in the 11 patients. Ten lesions were malignant, and in two lesions only nonneoplastic inflammatory tissue was found. The signal intensity (SI) of each lesion relative to that of muscle was determined visually and correlated with the histologic findings at surgery or biopsy. The SIs of malignant and benign lesions were indistinguishable. All lesions showed areas of high SI that correlated with carcinoma and tumor necrosis or with non-neoplastic inflammation and edema. Areas of low SI corresponded to reactive fibrous tissue (desmoplastic reaction) with small islands of tumor or to nonneoplastic fibrosis. MR imaging can be useful in determining the extent of suspected tumors, but SIs on T2-weighted images do not permit histologic diagnosis. In particular, distinction of benign from malignant tissue is difficult in tumors with a desmoplastic reaction. 相似文献
937.
938.
Pattern of endogenous lectins in a human epithelial tumor 总被引:1,自引:0,他引:1
Salt and detergent extracts of a malignant epithelial tumor, obtained by extraction of acetone powder, were fractionated on different sets of Sepharose columns covalently derivatized with lactose, asialofetuin, melibiose, mannan, fucose, and heparin. Successive elution by chelating reagent and specific sugar resulted in isolation of different Ca2+-dependent and Ca2+-independent endogenous carbohydrate-binding proteins, as analyzed by gel electrophoresis. It appears from the analysis that certain bands represent newly identified proteins capable of binding to lactose (at Mr 64,000), melibiose (at Mr 28,000), and fucose (at Mr 62,000 and 70,000). Other carbohydrate-binding proteins isolated from this human tumor have been identified in normal, especially embryonic, tissues of different nonhuman vertebrates. The carbohydrate-binding proteins are assayable as agglutinin with rabbit erythrocytes and show no detectable enzymatic activity. They can thus be defined as lectins. The presence of a complex pattern of endogenous lectins and their biochemical characteristics may contribute to an understanding of intercellular interaction during the complex process of metastatic spread and may furthermore allow a new tool for diagnosis and a lectin-based therapy. 相似文献
939.
Follow-up of 13 children who had had a ureterosigmoid anastomosis 3 1/2 to 10 years previously and whose initial urogram had been satisfactory, showed that growth was normal and that there was no serious metabolic disorder. In particular whole-body potassium did not differ significantly from normal values (as given by Langham, 1961). Asymptomatic urinary infection is the chief hazard in these cases but is difficult to diagnose and may lead to progressive dilatation of the ureters. 相似文献