地塞米松对肺癌切除术病人血清过氧化脂质胰岛素皮质醇的影响

４０例肺癌切除术病人，随机分为对照（Ｓ）组和地塞米松（Ｓ－Ｄ）组，采用氯胺酮－安氟醚静吸复合麻醉，对血清中过氧化脂质、胰岛素和皮质醇进行了初步观察。结果表明，血清过氧化脂质Ｓ－Ｄ组于手术毕显著低于Ｓ组（Ｐ〈０．０５）；血清胰岛素两组间没有统计学差异；血清皮质醇Ｓ－Ｄ组于气管插管后显著高于Ｓ组（Ｐ〈０．０５）。作者认为肺癌切除术病人术前给地塞米松可有效地降低血清中过氧化脂质含量，利于维护脏器功能。     

ACTH-producing cells of 21-day-old rat fetuses after maternal dexamethasone exposure

Adrenocorticotrophic hormone (ACTH) is essential for developmental maturation of numerous organ systems during the fetal period and for adaptation to environmental challenges. Immunocytochemical and stereological methods were used in the present study to examine the effects of dexamethasone (Dx) administration during pregnancy on fetal rat pituitary ACTH-producing cells. Doses of 0.5, 0.5 and 1.0 mg Dx/kg body weight/day were given to the dams on 3 consecutive days starting on day 16 of gestation. Morphometric analysis of the ACTH-producing cells of fetuses at 21 days of gestation revealed significant inhibition by 24% and 27%, respectively, of cell volume and cell number after maternal Dx administration, whereas the volume of cell nuclei and volume density of ACTH-stained cells were insignificantly decreased. Immunocytochemical analysis showed reduced numbers, sizes and immunopositivity of ACTH cells of 21-day-old fetuses from Dx-treated dams as compared with the control group. Maternal Dx treatment in the period of intense differentiation of the hypothalamo-hypophyseal-adrenal system had an inhibitory effect on fetal function and proliferative activity of ACTH-producing cells at 21 days of gestation. Thus, inhibition of activity of fetal ACTH-producing cells may lead to adrenal suppression, modified activity of the hypothalamo-pituitary-adrenal axis and reduced body weight possibly causing lasting functional abnormalities.     

Analysis of susceptibility of mature human T lymphocytes to dexamethasone-induced apoptosis

We present evidence that dexamethasone (Dex), a synthetic glucocorticosteroid, causes apoptosis in mature human T cells, similarly to what has been reported for murine T lymphocytes. Human T cell clones and short-term activated T lymphocytes treated with Dex show the characteristic pattern of apoptotic cells, such as hypodiploid nuclei, chromatin condensation and DNA fragmentation into oligonucleosomal fragments. However, Dex susceptibility of T cells to apoptosis is cell cycle-dependent. The progression in the proliferative cell cycle (G1 versus S) rescues Dex-treated T cells from apoptosis. Moreover, occupancy of the T cell receptor reverses Dex-induced apoptotic phenomena. These observations suggest that glucocorticoids contribute to the regulation of the proliferative or the suicidal response of antigen-activated human T cells.     

The categorical and dimensional models of endogenous depression

We calculated a Research Diagnostic Criteria (RDC) endogenous score for 257 depressed inpatients based on the number of endogenous criteria present. The distribution of RDC endogenous scores was unimodal. There was no association between endogenous scores and results of the Dexamethasone Suppression Test, or morbid risk for depression in the patients' first-degree relatives. The morbid risk for a family history of alcoholism tended to decrease with increasing endogenous scores, although a consistent steady decline was not observed. The results suggest that the RDC criteria do not fit either the categorical or dimensional model of endogenous classification. Potential sources of difficulty with the RDC endogenous criteria are discussed.     

大剂量激素对脑创伤家兔脑微循环及血液流变性的影响

为探讨大剂量激素对脑创伤后脑微循环及血液流变性的影响，将２４只家兔随机等分为３组：标准对照组、损伤对照组和地塞米松治疗组。分别在伤前０．５ｈ、伤后０．５ｈ、１ｈ、２ｈ、３ｈ测量软脑膜微动脉管径和血流速度的变化及伤后３ｈ血液流变学指标。结果表明：大剂量激素在伤后０．５ｈ就能明显地扩张损伤处软脑膜的微动脉并使血流速度明显加快。伤后３ｈ能明显降低血沉、全血粘度、红细胞压积及纤维蛋白原含量，并明显增强红细胞的变形能力，降低其聚集性。这些结果表明大剂量激素能明显改善脑创伤后家兔的脑微循环及血液流变性     

MMPI, personality dysfunction and the dexamethasone suppression test in major depression

In this study we examined the relationship of psychopathology and personality dysfunction to neuroendocrine functioning. MMPI profiles were examined for 30 psychiatric inpatients with major depression who were suppressors (60%) and nonsuppressors (40%) on the dexamethasone suppression test. There were no differences between suppressors and nonsuppressors on any of the MMPI scales or on DSM-III Axis-II diagnosis. When subdivided according to T-score elevations above 70 on MMPI scales 4 and 6, or 4 and 9, 30% of the sample, however, met criteria for personality dysfunction. Furthermore, a significantly higher proportion of suppressors (50%) evidenced personality dysfunction than did the nonsuppressors (8%). This suggests that certain MMPI scales are able to identify a subgroup of depressed patients with personality disturbances who also have a hypothalamic-pituitary-adrenal dysfunction.     

Mast cell populations in the chick embryo lung and their response to compound 48/80 and dexamethasone

Summary Two mast cell populations, connective tissue mast cells (CTMCs) and mucosal mast cells, (MMCs) containing different proteoglycans in their granules, can be distinguished in several animal species by means of histochemical methods. In this study we documented the presence of these two types of mast cell in the chick embryo lung, from the 15th incubation day for the MMCs, and from the 18th incubation day for the CTMCs. Lungs of embryos treated with compound 48/ 80, which produces degranulation of the CTMCs, showed a decrease in the number of this type of mast cell and an unchanged number of MMCs. In the lungs of embryos treated with dexamethasone, which degranulates MMCs, a reduction in the number of these cells and an unchanged number of the CTMs were found.     

急性肺血栓栓塞症兔TNF-α、IL-8、IL-10水平及地塞米松的影响

目的:探讨兔急性肺血栓栓塞症(PTE)时血浆及支气管肺泡灌洗液(BALF)中TNF-α,IL-8、IL-10的水平和地塞米松(Dex)的影响。方法:采用自体血栓回输法建立兔急性PTF模型。36只兔随机分为对照组、Dex治疗组和PTE模型组。用ELISA方法检测上述细胞因子(CK)水平,术毕肺组织行病理观察。结果:栓塞后上述CK均有升高,治疗后TNF-α、IL-8均有下降,IL-10变化不明显。组织病理学可见栓塞后肺动脉内血栓形成,肺组织萎缩、出血、炎性反应明显,Dex治疗后肺组织病理改变明显减轻。结论:PTE后促炎性CK在引起肺部炎性反应和肺组织及肺动脉病损中起了重要作用,抗炎治疗可以明显减轻CK引起的这种损伤。抗炎治疗能降低PTE急性期病死率,改善远期预后,CK可能起了很重要的作用。     

Dexamethasone and clenbuterol detection by enzyme immunoassay in Bovine Liver Tissue: A new multiresidue extraction procedure

A fast and simple extraction procedure was developed for simultaneous determination in bovine liver of two veterinary drugs, widely used as growth promoters in meat production: dexamethasone (a synthetic corticosteroid drug) and clenbuterol (a beta2‐adrenergic agonist drug). Liver samples were extracted by acetonitrile, without any clean‐up step. Two different ELISAs, specific for the two classes of drugs, were used to determine the residue concentration in the extracts. The intra‐ and inter‐extraction variability was determined at different concentrations: the intra‐extraction coefficients of variation (CVs) were between 2.5 and 17.7% for dexamethasone and between 0.9 and 9.8% for clenbuterol; the inter‐extraction CVs were between 2.0 and 16.8% for dexamethasone and between 0.5 and 10.8% for clenbuterol. Recovery ranged from 92 to 154% for dexamethasone and from 78 to 105% for clenbuterol. The limit of detection was 1.43 ng g^?1 and 0.43 ng g^?1, respectively. The limit of quantification for dexamethasone was 2.09 ng g^?1 and for clenbuterol was 0.72 ng g^?1. The combination of the new extraction procedure with an ELISA detection permitted the rapid semi‐quantitative determination of both dexamethasone at its maximum residue level (MRL: 2.5 ng g^?1 in liver tissue), and clenbuterol at low concentration level.     

Dexamethasone loaded bioresorbable films used in medical support devices: structure, degradation, crystallinity and drug release

Bioresorbable polymer films containing dexamethasone (DM) were prepared using a solution processing technique. Investigation of the films focused on cumulative DM release as affected by film morphology (drug location/dispersion in the film) and degradation processes. Two film structures were studied: A-type, a polymer film with large drug crystals located on the film’s surface, and B-type, a polymer film with small drug particles and crystals distributed within the bulk. The effect of the polymer’s degree of crystallinity on the drug release profile was also studied. Prototypical applications of these films are biodegradable medical support devices which combine mechanical support with drug release. In most of our studied systems the drug release profile from the film is determined mainly by both drug location/dispersion in the film and the polymer’s weight loss rate. All release profiles from A-type films exhibited a burst effect of approximately 30%, accompanied by a second release phase at a constant rate, whereas the release profiles from B-type films were determined mainly by the degradation profile of the host polymer, and did not exhibit any burst effect. A high degree of crystallinity is important for the current application, since good mechanical properties are required. This contributes to slower drug release rates, mainly at relatively low weight losses, whereas at high weight losses, where a porous structure is created, the crystallinity almost does not affect the rate of drug release. The shape of the porous structure that develops with degradation also affects the drug release profile from the B-type films.