铅对作业工人某些内分泌腺功能影响的研究

本文研究发现铅吸收、铅中毒工人血中游离三碘甲状腺原氨酸（ＦＴ＿３）、游离四碘甲状腺原氨酸（ＦＴ－４）、皮质醇含量明显低于对照组工人（Ｆ＜０．０１），且与尿铅、尿δ－ＡＬＡ含量呈明显负相关；铅中毒工人血中ＴＳＨ明显高于对照组工人（Ｐ＜０．０１），且与尿铅、尿δ－ＡＬＡ含量呈明显正相关。结果提示，接铅工人体内铅负荷达铅吸收水平，但尚未产生中毒症状时就已影响了甲状腺、肾上腺皮质的分泌功能，说明某些内分泌腺对铅的损伤作用较敏感，铅损伤某些内分泌腺的功能可能是铅中毒的重要机理之一。     

An unexpected cause of chronic cough in a young woman: Tachycardia-induced cardiomyopathy

Heart failure typically manifests with exertional dyspnea or limb edema. Old age, underlying heart disease, and coronary risk factors are known risk factors for heart failure. Thus, congestive heart failure is rarely considered as a differential diagnosis of chronic cough in a previously healthy young person. However, tachycardia-induced cardiomyopathy (TIC) can result in such a situation. A case of a previously healthy 27-year-old woman with TIC is described herein. On the first examination, the patient presented with left ventricular (LV) dysfunction caused by persistent tachyarrhythmia. Cardiomyopathy subsided with only heart rate control; therefore, the patient was diagnosed as having TIC. TIC can develop irrespective of age and underlying heart disease. The long-term outcome may be good, and LV systolic function recovers in most patients following resolution of arrhythmia. Physicians need to consider TIC as a differential diagnosis in patients of any age who present with heart failure, because prompt treatment generally leads to resolution of symptoms and ventricular function.     

Synergistic antidiabetic activity of Vernonia amygdalina and Azadirachta indica: biochemical effects and possible mechanism

Ethnopharmacological relevance

A decoction from a combination of herbs is commonly used in Traditional African Medicine for the management of chronic ailments. In Nigeria, the leaves of Vernonia amygdalina Del. (VA) and Azadirachta indica A. Juss (AI) are used traditionally as a remedy against diabetes mellitus for which empirical evidence attests to its efficacy.

Aim of the study

To evaluate the synergistic antidiabetic action of VA and AI, the biochemical effects and possible mechanism in streptozotocin-induced diabetic rat (SDR) models.

Materials and methods

Ethanolic extracts of VA and AI were co-administered (200 mg/kg, 50:50) to non-diabetic rats (NDRs) and SDRs for 28 days. Blood glucose and body weight were monitored during this period, and at end of treatment, serum glucose, insulin, triiodothyronine (T3), tetraiodothyronine (T4) and α-amylase activity were studied. Glucose and activities of antioxidant enzymes, e.g., catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), were estimated in hepatocytes, along with the impact on the histology of the liver and pancreas. Medium acting insulin, HU (5 IU/kg, s.c.) was used as a positive control.

Results

The study reveals that compared with single extracts, the combined extract (VA/AI) promptly lowered blood glucose and maintained a relatively steady level over the study period, in tandem with HU. During this period, body weight gain successively increased. In SDRs, fasting blood glucose at days 0 and 28 was raised by 4.33 and 3.16 fold, respectively, and the serum glucose was raised by 7.70 fold vs. normal control (P < 0.05). The discrepancies in the individual effects of VA and AI on hepatic glucose and α-amylase activity were also restored. In NDRs, VA/AI lowered blood and serum glucose (1.14 and 1.94 fold, respectively), although to a lesser extent when compared with HU. Furthermore, VA/AI was found to lower serum insulin, T3 and T4 by 1.66, 1.57 and 2.16 fold, respectively, in SDR (P < 0.05). This was similar to HU, which demonstrated 1.79 and 1.68 fold reduction of insulin and T3, respectively (P < 0.05), but had no effect on T4. Conversely, in NDRs, VA/AI caused 1.32, 4.93 and 1.04 fold increase in insulin, T3 and T4, respectively, reciprocal to its effect on blood and serum glucose. Oxidative stress in SDR, characterised by decreased GPx and CAT activities, was ameliorated, as the activities of the enzymes and SOD increased following a 28-day treatment with VA/AI (P < 0.05). The features of diabetic pathology, indicated in the histology of the liver and pancreas, were reversed. However, the extent of recovery was partial with VA, better with AI, and distinct and total with VA/AI, compared with a null effect by HU.

Conclusion

Taken together, our results contribute towards validation of enhanced antidiabetic efficacy of VA and AI when combined. This synergy may be exerted by oxidative stress attenuation, insulin mimetic action and β-cell regeneration.     

Absence of adverse effect on thyroid function and red blood cells in a population of workers exposed to cobalt compounds

Context

Hypothyroidism has been observed in the fifties and sixties as an undesirable side-effect of cobalt therapy used for its erythropoietic properties in the treatment of anemia.

Objective

This study aims at evaluating the possible impact of both cumulative (long-term) and recent occupational exposure to cobalt on thyroid function and red blood cells.

Methods and setting

A cross-sectional survey was conducted from February 2008 to August 2009 in a population of 249 male workers from a cobalt production department in the North of Belgium. The possible effect of cobalt exposure on thyroid and red blood cells was investigated through multiple regression analyses.

Results

Blood cobalt ranged from undetectable to 3.20 μg/100 ml (median 0.10); urinary cobalt from 0.30 to 204.30 μg/g_creat (median 3.90) and long-term exposure to cobalt ranged from 0.15 to 6990.46 μg/g_creat·years (median 106.09). No effect of cobalt exposure on thyroid or red blood cell parameters was observed at these levels of exposure.

Conclusion

The results support the absence of effects on the thyroid and red blood cells when occupational exposure to cobalt is kept below the recommended biological limit of occupational exposure (15 μg Co/g_creat in urine).     

新生儿硬肿症患儿SOD、T_4、TSH的变化及相关关系探讨

对比观察了21例正常儿和19例新生儿硬肿症患者血清超氧化物歧化酶（SOD）、四碘甲状腺素（T4）及促甲状腺激素（TSH）含量的变化，并将三项指标进行相关分析。结果发现：硬肿症患儿SOD活性及T4含量明显低于对照组（P均＜0．001）；TSH含量与正常组相比无统计学差别；硬肿症患儿SOD活性与T4含量呈正相关（r＝0．581，P＜0．01），T4与TSH无相关性（r＝－0．257，P＞0．05）。提示：自由基的损伤作用及甲状腺功能低下参与该病的病理生理过程；T4的下降可能是由于自由基损伤甲状腺所致。     

胎儿生长受限脐血中T_3、T_4、TSH变化及其意义

目的:探讨胎儿生长受限脐血中甲状腺激素的变化。方法:采用化学发光免疫分析法,测定正常足月妊娠50例和足月妊娠FGR 30例脐血中三碘甲腺原氨酸(T3)、甲状腺素(T4)和促甲状腺素(TSH)水平。结果:FGR组脐血中T4显著下降(P<0.01),TSH明显升高(P<0.01)。结论:甲状腺功能减退可能与FGR的发病有关。     

甲状腺功能减退症与先兆流产的相关性及治疗

近年来的研究发现甲减与先兆流产的关联性主要与下丘脑—垂体—卵巢轴调节、甲状腺素与卵泡刺激素的协同作用、自身免疫失衡、甲状腺相关抗体等因素有关,而中医方面认为两者主要病机都为脾肾阳虚,故甲减可致胞宫失养,系胎无力,最终发为"胎漏""胎动不安"。在临床过程中,防治甲状腺功能减退症已成为控制先兆流产发生率的必要措施之一,除西医的常规治疗方法外,中医根据其发病机制,主要以益气健脾、补肾温阳之法调整体内气血平衡,从而改善机体内分泌代谢状态,降低血清TSH水平,最终达到减少流产的目的。目前临床中主要有单纯中药疗法、中西医结合疗法及针刺疗法,而中西医疗法因其突出的疗效而被临床广泛应用。     

血清T_3、T_4和γT_3水平变化在心脏病心衰病情及疗效观察中的应用

观察心脏病心衰时，血清Ｔ３、Ｔ４和γＴ３水平的变化与其病情及治疗疗效间的相关关系。方法应用放射免疫法测定心脏病患者心衰纠正前后血清Ｔ３、Ｔ４和γＴ３水平，并计算了Ｔ３／γＴ３和Ｔ４／γＴ３比值。结果３２例心脏病心衰患者血清检查中，Ｔ３水平显著降低（较对照组低４４．４％），心衰纠正后未见升高；γＴ３水平呈增高趋向，心衰纠正后降至正常以下；Ｔ４水平无明显改变。结论Ｔ３、Ｔ４和γＴ３水平以及Ｔ３／γＴ３和Ｔ４／γＴ３均可作为观察心脏病心衰的有效指标，并对心脏病心衰患者治疗疗效观察具有一定意义。     

电焊工人某些内分泌腺功能研究

应用ＲＩＡ方法测定５１名电焊作业工人血清中ＦＴ３、ＦＴ４、ＴＳＨ及ＣＳ的含量，评价锰对垂体、甲状腺及肾上腺皮质功能的影响。结果发现：工人接触锰尘平均浓度为０．１３～０．３３ｍｇ／ｍ３，血清中ＦＴ３、ＦＴ４、ＴＳＨ含量与对照组比较差异均无显著性，说明垂体、甲状腺的分泌功能未受到损害；血清中ＣＳ含量１０年以上各工龄组明显低于对照组，有显著性或高度显著性差别（Ｐ＜０．０５或０．０１），说明作业工人肾上腺皮质分泌功能受到一定的损害。推荐可将测定作业工人血中ＣＳ含量，作为锰的损害作用较早期的生物学指标。     

乙醇对雄性大鼠甲状腺和肾上腺皮质功能影响

目的研究乙醇对雄性大鼠甲状腺和肾上腺皮质功能的影响。方法给予雄性大鼠每天１５００ｍｇ／ｋｇ,３０００ｍｇ／ｋｇ和４０００ｍｇ／ｋｇ体重乙醇染毒连续７０天,并于染毒第３５天和７０天每组随机处死１０只,经腹主动脉采血,测定对照组及各剂量组血清ＦＴ３,ＦＴ４,ＴＳＨ和ＣＳ含量。结果染毒３５天各剂量组大鼠血清中ＦＴ３,ＦＴ４,ＴＳＨ和ＣＳ未发现有意义的改变;染毒７０天３０００ｍｇ／ｋｇ和４０００ｍｇ／ｋｇ组ＦＴ３含量较１５００ｍｇ／ｋｇ组下降,而４０００ｍｇ／ｋｇ组ＦＴ４含量较１５００ｍｇ／ｋｇ和３０００ｍｇ／ｋｇ组下降,差异均有显著性（Ｐ＜０．０５）;染毒７０天４０００ｍｇ／ｋｇ组ＣＳ含量较对照组升高,差异有显著性（Ｐ＜０．０５）,且存在明显的剂量－效应关系。结论乙醇在一定程度上损害了大鼠甲状腺及肾上腺皮质的功能。