血清CTRP13和UACR与不稳定型心绞痛合并2型糖尿病的相关性研究

目的 探讨血清补体C1q/肿瘤坏死因子相关蛋白13(CTRP13)及尿微量白蛋白/肌酐比值(UACR)与不稳定型心绞痛(UAP)合并2型糖尿病(T2DM)的关系。方法 选取2019年10月—2020年10月在承德医学院附属医院心内科和内分泌科住院的150例患者,根据是否诊断UAP和T2DM分为UAP+T2DM组(n＝50)、UAP组(n＝50)和T2DM组(n＝50),选取同期体检的健康人为对照组(n＝50)。分别测定四组患者的血清CTRP13浓度和晨尿UACR水平。比较各组间的一般资料及CTRP13和UACR水平的差异,分析UAP+T2DM组CTRP13和UACR与各指标的相关性;使用倒数f[CTRP13(ng/L)]＝1/[CTRP13(ng/L)]转换CTRP13(ng/L),用ROC曲线分析f(CTRP13)和UACR单独检测及联合检测对UAP+T2DM的预测效能。结果 血清CTRP13水平在UAP+T2DM组最低,T2DM组和UAP组次之,对照组水平最高(P＜0.05);UACR水平在UAP+T2DM组最高,UAP组和T2DM组次之,对照组最低(P＜0.05)。UAP+T2DM组Gensini评分高于UAP组(P＜0.05)。相关性分析显示,在UAP+T2DM组,血清CTRP13水平与空腹血糖(FPG)、高敏C反应蛋白(hs-CRP)及Gensini评分呈负相关,与高密度脂蛋白胆固醇(HDLC)呈正相关(均P＜0.05);UACR与腰围、低密度脂蛋白胆固醇(LDLC)、hs-CRP及Gensini评分呈正相关(均P＜0.05)。ROC曲线显示,f(CTRP13)、UACR单独检测及联合检测预测UAP合并T2DM的曲线下面积(AUC)分别为0.820(95%CI:0.759～0.882)、0.846(95%CI:0.786～0.905)和0.876(95%CI:0.820～0.931),其灵敏度分别为88%、82%和86%,其特异度分别为64%、80%和77.3%。结论 CTRP13和UACR不仅可作为UAP合并T2DM患者临床诊断的辅助指标,还可用于评估冠状动脉病变的严重程度;二者联合检测对UAP合并T2DM的诊断价值更高。     

2型糖尿病患者血尿酸水平与动脉粥样硬化的相关性研究

目的探讨血尿酸(SUA)水平升高与T2DM患者动脉粥样硬化(AS)风险增高的相关性。方法选取T2DM患者248例,将SUA水平按照三分位法进行分组,采用B型超声检测各组颈动脉内-中膜厚度(CIMT)。结果 SUA水平与WC、BMI、FIns、TC、LDL-C、血肌酐(Scr)和CIMT呈正相关(P0.01),与T2DM病程、FPG、HbA1c和肾小球滤过率(eGFR)呈负相关(P0.01)。校正年龄、性别、T2DM病程、吸烟、饮酒、HbA1c、LDL-C、eGFR、HOMA-IR和BMI等因素后,高分位组CIMT发生颈AS风险高于低分位组[OR(95%CI):2.96(1.83~4.25),P=0.019]。结论 SUA水平是T2DM患者AS的独立危险因素。     

血清可溶性低密度脂蛋白受体11水平与2型糖尿病及颈动脉内-中膜厚度关系的研究

目的探讨血清可溶性低密度脂蛋白受体11(sLR11)水平与T2DM及颈动脉内-中膜厚度(CIMT)的关系及其临床意义。方法选取新诊断T2DM患者(T2DM组)51例及同期健康体检者(NC组)55名,ELISA测定血清sLR11水平,比较两组sLR11、CIMT、年龄、血脂及血压。另选常规治疗的T2DM患者165例,分析sLR11、CIMT与动脉硬化危险因素之间的关系,以及CIMT进展中sLR11与FPG的影响。结果 T2DM组血清sLR11、CIMT均高于NC组[(8.35±2.65)vs(6.64±1.99)ng/ml,P=0.026;(0.87±0.37)vs(0.73±0.26)mm,P=0.037]。165例T2DM患者中,血清sLR11水平为(9.79±3.54)ng/ml,CIMT为(0.79±0.18)mm。相关分析显示,sLR11水平与年龄、SBP、LDL-C、FPG、HbA_1c呈正相关(r=0.226、0.162、0.166、0.276、0.176,P0.05);多元线性回归分析显示,FPG与血清sLR11独立相关(β=0.175,P=0.023);不考虑年龄因素时,sLR11是CIMT的独立危险因素(β=0.008,P=0.044)。结论血清sLR11可能与T2DM血糖相关,并反映CIMT情况及血管内膜平滑肌细胞病理变化。     

半乳糖凝集素3与2型糖尿病患者颈动脉粥样硬化相关性的研究

目的探讨T2DM患者血清半乳糖凝集素3(Gal-3)与颈动脉粥样硬化(CAS)的相关性。方法选取新诊断T2DM患者94例,根据有无CAS分为合并CAS组(T2DM+CAS,n=48),不合并CAS组(T2DM,n=46);另选取糖耐量正常的CAS患者为CAS组(n=47);选取同期健康体检者为正常对照组(NC,n=48)。检测各组FPG、HbA_1c、高敏C反应蛋白(hsC-RP)、颈动脉内膜中层厚度(CIMT)、FIns、稳态模型评估胰岛素抵抗指数(HOMA-IR),ELISA法测定血清Gal-3水平。结果 T2DM+CAS组血清Gal-3水平高于其余三组(P0. 05或P0. 01)。Pearson相关分析显示,血清Gal-3水平与BMI、FPG、2 hPG、HbA_1c、FIns、hsC-RP、HOMA-IR、CIMT呈正相关(P0. 05或P0. 01),与超氧化物歧化酶呈负相关(P0. 01)。多元逐步回归分析显示,HbA_1c、Gal-3是T2DM患者CIMT的影响因素。Logistic回归分析显示,HbA_1c、Gal-3是CAS的影响因素。结论 T2DM、CAS患者血清Gal-3升高,是T2DM患者发生CAS的影响因素。     

2型糖尿病患者血清miR-320表达与糖尿病视网膜病变的相关性研究

目的探讨T2DM患者血清miR-320表达与DR的相关性。方法选取2018年5月至2020年5月于孝感市中心医院内分泌和风湿科住院治疗的T2DM患者262例,根据DR诊断及分期标准将患者分为非DR组(non-DR,n=83),非增殖性DR组(非增殖组,n=85),增殖性DR组(增殖组,n=94)。比较各组患者一般资料和主要生化指标,实时荧光定量PCR术检测各组血清miR-320表达。结果增殖组年龄高于non-DR、非增殖组(P0.05)。non-DR、非增殖和增殖组DM病程、FPG、HbA1c、HOMA-IR依次升高(P0.05)。非增殖组eGFR、miR-320水平高于增殖组(P0.05)。Pearson相关分析显示,T2DM患者血清miR-320表达与eGFR呈正相关(P0.05),与DM病程、TG、LDL-C、FPG、HbA1c和HOMA-IR呈负相关(P0.05)。Logistic回归分析显示,DM病程、TG、LDL-C、FPG、HbA1c、HOMA-IR、e GFR和miR-320表达是T2DM患者发生DR的影响因素。T2DM患者血清miR-320表达量预测发生DR时,曲线下面积为0.788(95%CI 0.734,0.842),当miR-320表达量为0.90时,灵敏度为63.13%,特异度为91.57%。结论 T2DM患者发生DR时血清miR-320表达降低,且与DR病程进展及糖脂代谢指标相关,是发生DR的危险因素,可能是预测T2DM患者发生DR的潜在生物学标志物。     

血清Neuregulin 4水平与2型糖尿病患者颈动脉内-中膜厚度的相关性研究

目的探讨血清脂肪因子Neuregulin 4(Nrg4)水平与T2DM患者颈动脉内-中膜厚度(CIMT)的关系。方法选择T2DM患者85例,颈动脉彩色超声测定CIMT,CIMT0.9 mm为CIMT正常组(n=39),CIMT0.9 mm为CIMT增厚组(n=46),另选健康对照(NC)组(n=44)。ELISA测定Nrg4浓度,同时测定其他代谢指标。结果 NC组、CIMT正常组和CIMT增厚组血清Nrg4浓度依次下降(P0.05或P0.01)。Spearman相关分析显示,CIMT与FPG、胰岛素抵抗指数(HOMA-IR)及糖尿病病程呈正相关(r=0.412、0.516、0.314,P0.01),与HDL-C及Nrg4呈负相关(r=-0.475、-0.373,P0.01)。多元线性回归分析显示,FPG、Nrg4、HDL-C是CIMT的独立影响因素。结论脂肪因子Nrg4血清浓度在T2DM合并CIMT增厚患者中下降,可能在T2DM动脉粥样硬化形成中发挥作用。     

2型糖尿病患者亚临床甲状腺功能减退与颈动脉硬化的相关性

目的:探讨2型糖尿病(T2DM)患者亚临床甲状腺功能减退(SCH)与颈动脉内膜中层厚度(CIMT)的相关性。方法:选择本院住院的T2DM患者111例,其中甲状腺功能正常的患者60例,T2DM合并SCH患者51例,比较2组患者体质量指数(BMI)、血糖、糖化血红蛋白、血脂及CIMT等指标。采用直线相关和线性回归分析各因素与CIMT的关系。结果 :与甲状腺功能正常的T2DM患者比较,合并SCH的T2DM患者糖、脂代谢紊乱更严重,CIMT增厚明显,差异均有统计学意义(均P<0.05)。多元线性逐步回归分析结果显示,促甲状腺激素(TSH)是CIMT的独立危险因素。结论:T2DM合并SCH患者糖、脂代谢紊乱程度更为严重,T2DM合并SCH促使CIMT明显增厚,由此增加糖尿病患者发生动脉粥样硬化的风险。     

2型糖尿病患者发生慢性肾脏病的危险因素及与肥胖的相关性研究

目的研究2型糖尿病(T2DM)患者发生慢性肾脏病(CKD)的危险因素,并着重分析肥胖与CKD发生的关系。方法纳入2009年1月至2019年6月在南京鼓楼医院就诊的18至75岁诊断为T2DM的患者,收集一般资料包括性别、年龄、体重指数(BMI)、收缩压、舒张压、糖尿病病程以及实验室指标包括血红蛋白(Hb)、白蛋白、丙氨酸转氨酶(ALT)、天冬氨酸氨基转移酶(AST)、总胆红素(TBIL)、尿酸、空腹血糖(FPG)、糖化血红蛋白(HbA1c)、甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、尿白蛋白/肌酐比值和估算的肾小球滤过率。肥胖定义为BMI≥28 kg/m²,超重定义为24 kg/m²≤BMI<28 kg/m²。根据是否合并CKD,将研究对象分为合并CKD组和不合并CKD组。在不合并CKD的T2DM患者中,选取至少随访一次,随访时间超过12个月且随访数据完整的患者,按是否发生CKD分为发生CKD组和未发生CKD组。两组间各指标的比较采用t检验、非参数检验以及χ²检验。采用单因素及多因素logistic回归分析法分析T2DM患者发生CKD的危险因素,采用Cox比例风险模型分析随访的T2DM患者CKD发生的危险因素。采用限制性立方样条(RCS)拟合Cox回归模型来评估不同的BMI截点与CKD的关系。结果共纳入3194例T2DM患者,其中合并CKD组620例,不合并CKD组2574例。与不合并CKD组相比,合并CKD组T2DM患者BMI明显增高(P=0.005)。单因素logistic回归分析结果显示,性别、肥胖、收缩压、舒张压、Hb、白蛋白、TG、TC、FPG及HbA1c为T2DM患者发生CKD的影响因素(均P<0.05),将上述指标作为自变量,进行多因素logistic回归分析,结果显示,肥胖(OR=1.058,95%CI 1.079~2.018),收缩压增高(OR=1.027,95%CI 1.018~1.035),TG增加(OR=1.087,95%CI 1.008~1.171),FPG增高(OR=1.042,95%CI 1.003~1.083)是T2DM患者发生CKD的影响因素(均P<0.05)。不合并CKD组中随访时间超过12个月且随访数据完整的T2DM患者共753例,其中,发生CKD组182例,未发生CKD组571例。Cox比例风险模型分析结果显示,在校正年龄、糖尿病病程、收缩压、AST、TG及FPG后,超重为发生CKD的危险因素(OR=1.95,95%CI 1.05~3.61)。RCS拟合Cox回归模型结果显示,T2DM患者BMI与CKD发生风险呈非线性关系,BMI在28~31 kg/m²的T2DM患者CKD的发生风险增加(均P<0.05)。结论T2DM患者肥胖与CKD密切相关,肥胖的T2DM患者,特别是BMI在28~31 kg/m²,容易发展为CKD。     

2型糖尿病患者发生慢性肾脏病的危险因素及与肥胖的相关性研究

目的研究2型糖尿病(T2DM)患者发生慢性肾脏病(CKD)的危险因素,并着重分析肥胖与CKD发生的关系。方法纳入2009年1月至2019年6月在南京鼓楼医院就诊的18至75岁诊断为T2DM的患者,收集一般资料包括性别、年龄、体重指数(BMI)、收缩压、舒张压、糖尿病病程以及实验室指标包括血红蛋白(Hb)、白蛋白、丙氨酸转氨酶(ALT)、天冬氨酸氨基转移酶(AST)、总胆红素(TBIL)、尿酸、空腹血糖(FPG)、糖化血红蛋白(HbA1c)、甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、尿白蛋白/肌酐比值和估算的肾小球滤过率。肥胖定义为BMI≥28 kg/m²,超重定义为24 kg/m²≤BMI<28 kg/m²。根据是否合并CKD,将研究对象分为合并CKD组和不合并CKD组。在不合并CKD的T2DM患者中,选取至少随访一次,随访时间超过12个月且随访数据完整的患者,按是否发生CKD分为发生CKD组和未发生CKD组。两组间各指标的比较采用t检验、非参数检验以及χ²检验。采用单因素及多因素logistic回归分析法分析T2DM患者发生CKD的危险因素,采用Cox比例风险模型分析随访的T2DM患者CKD发生的危险因素。采用限制性立方样条(RCS)拟合Cox回归模型来评估不同的BMI截点与CKD的关系。结果共纳入3194例T2DM患者,其中合并CKD组620例,不合并CKD组2574例。与不合并CKD组相比,合并CKD组T2DM患者BMI明显增高(P=0.005)。单因素logistic回归分析结果显示,性别、肥胖、收缩压、舒张压、Hb、白蛋白、TG、TC、FPG及HbA1c为T2DM患者发生CKD的影响因素(均P<0.05),将上述指标作为自变量,进行多因素logistic回归分析,结果显示,肥胖(OR=1.058,95%CI 1.079~2.018),收缩压增高(OR=1.027,95%CI 1.018~1.035),TG增加(OR=1.087,95%CI 1.008~1.171),FPG增高(OR=1.042,95%CI 1.003~1.083)是T2DM患者发生CKD的影响因素(均P<0.05)。不合并CKD组中随访时间超过12个月且随访数据完整的T2DM患者共753例,其中,发生CKD组182例,未发生CKD组571例。Cox比例风险模型分析结果显示,在校正年龄、糖尿病病程、收缩压、AST、TG及FPG后,超重为发生CKD的危险因素(OR=1.95,95%CI 1.05~3.61)。RCS拟合Cox回归模型结果显示,T2DM患者BMI与CKD发生风险呈非线性关系,BMI在28~31 kg/m²的T2DM患者CKD的发生风险增加(均P<0.05)。结论T2DM患者肥胖与CKD密切相关,肥胖的T2DM患者,特别是BMI在28~31 kg/m²,容易发展为CKD。     

血清胰高血糖素样肽-1水平可预测新诊断2型糖尿病患者的颈动脉粥样硬化

目的：探讨新诊断2型糖尿病（T2DM）患者血清胰高血糖素样肽-1（GLP-1）水平与颈动脉粥样硬化（CAS）的相关性。 方法：选择T2DM患者180例，均接受颈动脉超声检查，分为单纯T2DM组（78例）和T2DM合并CAS组（DMCAS 组，102例），另选取本院同期健康体检者60例为对照组，比较3组临床检查指标；多因素 logistic 回归分析T2DM患者并发CAS的独立影响因素， 将DMCAS 组患者根据CAS分级分为1、2、3级，比较不同分级的空腹血糖（FPG）、低密度脂蛋白胆固醇(LDL)、GLP-1 和颈动脉内中膜厚度(IMT)水平。统计学分析GLP-1与CAS分级、FPG、LDL和IMT的相关性。受试者工作特征（ROC）曲线分析GLP-1对T2DM合并CAS发生的预测价值。 结果：FPG、LDL、GLP-1和IMT为T2DM患者合并CAS的独立危险因素（P均<0.05）。GLP-1与CAS分级、FPG、LDL和IMT呈显著负相关（P均<0.05）。预测T2DM患者CAS发生的最佳GLP-1水平为6.59 pmol/L（P<0.05）。 结论：T2DM合并CAS患者血清GLP-1水平明显降低，且与CAS严重程度相关；GLP-1水平能在一定程度上预测T2DM患者CAS的发生。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

Effects of pinealectomy and melatonin administration on certain indices of ovarian hyperplasia and/or hypertrophy in rats with both ovaries intact or after unilateral ovariectomy

Abstract: In earlier studies from other laboratories it was shown that melatonin decreased ovarian weight in rats and inhibited compensatory hypertrophy of the remaining ovary after unilateral ovariectomy. This study was designed to examine the influence of melatonin on certain indices of ovarian hyperplasia and/or hypertrophy in adult female rats with both ovaries preserved and with either an intact pineal gland or with the pineal gland removed (pinealectomy, PX) or, finally, in sham-PX animals. Similar studies were conducted on rats after unilateral ovariectomy, referring the examined parameters to the remaining intact ovary. The studies included mitotic activity of granulosa layer cells and corpus luteum cells, ovarian weight, ovarian cross-sectional area, cross-sectional area of the granulosa layer of all the Graafian follicles and the cross-sectional areas of the corpora lutea, visible on the ovarian cross-section. On the basis of results, we conclude that: 1) the effect of PX on the processes of ovarian hyperplasia and hypertrophy may vary; analogously, exogenous melatonin administration may influence ovarian hyperplasia and hypertrophy in different ways; 2) PX and exogenous melatonin may, under certain conditions, exert similar biological effects, even synergistic effects; 3) melatonin inhibits ovarian growth processes, while the effects of PX are variable; 4) the results indicate that in experiments performed on rats, with the use of two control groups, i.e., intact and sham-PX, melatonin effects on these two groups may differ.