芍药苷对STZ损伤的INS-1细胞的保护和修复作用

目的 研究中药单体芍药苷对INS-1细胞的影响,及对链脲佐菌素(STZ)损伤的胰岛细胞的保护、修复作用,并初步探讨其保护机制.方法 INS-1细胞传代培养后,用四氮唑蓝(MTT) 比色法测定细胞增殖活力,并测定细胞培养液中胰岛素浓度、丙二醛( MDA) 浓度、总抗氧化能力(T-AOC ).结果 芍药苷可促进INS-1细胞释放胰岛素.STZ损伤后,INS-1细胞活力降低;胰岛素分泌量减少;MDA含量明显升高;T-AOC下降.芍药苷保护组能不同程度改善STZ引起的上述指标的改变.结论 芍药苷可促进INS-1细胞释放胰岛素,对STZ损伤的INS-1细胞有显著的保护作用,这种作用可能是通过提高INS-1细胞的抗氧化能力实现的.     

原花青素对STZ致胰岛细胞损伤的保护作用

目的 探讨原花青素(PC)对链脲佐菌素(STZ)损伤大鼠胰岛素瘤细胞(INS-1)的保护作用.方法 INS-1细胞培养24 h后,以链脲佐菌素(STZ)损伤细胞,将细胞分为正常对照组、STZ组、PC保护组(PC +STZ),PC保护组培养液中加入不同浓度的PC干预12h后,用MTT比色法测定细胞存活率,用放免法检测培养细胞上清液胰岛素分泌量的变化,用比色法测定培养细胞上清液丙二醛( MDA)和超氧化物歧化酶(SOD)等指标的变化.结果 PC可以减少STZ对INS-1细胞的损伤,PC保护组的INS-1细胞存活率增加(P＜0.01);与STZ组比较,PC保护组促进了INS-1细胞的胰岛素分泌(P＜0.01),降低了INS-1细胞的MDA含量(P＜0.01),增强了T-AOC的活性(P＜0.01).结论 原花青素对STZ损伤INS-1细胞有一定的保护作用,其机制可能是通过降低MDA生成,提高T-AOC能力有关.     

内源性雌激素对STZ诱导雌性小鼠糖尿病的保护作用研究

目的 研究内源性雌激素对糖尿病小鼠血糖、血清胰岛素水平和抗氧化能力的影响,探讨内源性雌激素对胰岛细胞和胰岛素敏感性可能的保护作用.方法 小鼠按体重随机分为4组,假手术组(Sham)、去卵巢手术组(Ovx)、假手术注射链脲佐菌素(streptozotocin,STZ)组(Sham+ STZ)、去卵巢手术注射STZ组(Ovx+STZ).切除小鼠两侧卵巢,腹腔注射STZ制糖尿病小鼠模型.跟踪测定体重、血糖,进行糖耐量试验.取血制血清,取出胰腺于4％多聚甲醛中固定.测定血清中胰岛素浓度,丙二醛(MDA)、总抗氧化力( T-AOC),所取胰腺做病理切片,观察胰岛细胞的变化.结果 Ovx组血糖和MDA值明显高于Sham组,总抗氧化力低于Sham组;Ovx+STZ血糖和MDA值高于Sham+STZ组,胰岛素水平和T-AOC要低于Sham+STZ组.结论 内源性雌激素对糖尿病小鼠具有一定保护作用.     

肺炎衣原体感染影响胰岛β细胞增殖和功能的体外研究

目的 探讨肺炎衣原体(C.pn)感染对胰岛β细胞增殖和功能的影响.方法 将C.pn在人喉癌细胞系(HEp-2细胞)中增殖培养后,以感染复数为0.08、0.20,干预时间为6,24 h的C.pn感染体外培养的胰岛β细胞系(INS-1细胞),通过光镜下观察细胞形态变化及免疫荧光单克隆抗体染色方法确认感染模型的建立.在不同感染复数(0,0.04,0.08,0.10,0.12,0.14,0.16,0.20)、不同干预时间(2,4,6,8,16,24,36 h)的C.pn作用下,利用四甲基偶氮唑蓝法、台盼蓝活细胞计数及流式细胞仪观察C.pn感染对INS-1细胞增殖和凋亡的影响;并通过放射免疫法测定C.pn感染后经高糖(25 mmol/L)和低糖(5.6 mmol/L)刺激的INS-1细胞胰岛素分泌量.结果 与正常对照组相比,小剂量(0.08)加短时间(6 h)C.pn感染组INS-1细胞密度增加,细胞间隙变窄,大剂量(0.20)加长时间(24 h)C.pn感染组INS-1细胞骤缩、变圆、仍聚团生长.免疫荧光单克隆抗体染色显示特异性亮绿色荧光,证实C.pn感染INS-1细胞的体外模型成功建立.与正常对照组相比,小剂量(＜0.20)加短时间(＜24 h)的C.pn感染促进INS-1细胞增殖(t=-8.907,P ＜0.05)及INS-1细胞分泌胰岛素(t=-9.186,P＜0.05),而大剂量(＞0.20)加长时间(＞24 h)的C.pn感染则促进INS-1细胞凋亡(t=-37.306,P＜0.05)且抑制INS-1细胞分泌胰岛素(t=9.592,P＜0.05).结论 C.pn感染对胰岛β细胞增殖和功能具有双向作用,可为2型糖尿病早期防治提供新思路.     

节旋藻藻胆蛋白对果蝇总抗氧化能力和丙二醛的影响

目的 研究节旋藻藻胆蛋白对果蝇体内总抗氧化能力(T-AOC)和丙二醛(MDA)含量的影响.方法 采用鄂尔多斯钝顶节旋藻藻胆蛋白(P1)和Chad湖钝顶节旋藻藻胆蛋白(P2)分别配制0.25％、0.50％和1.00％浓度的含蛋白培养基,以普通培养基为对照组、喂饲果蝇并测定各剂量组果蝇体内T-AOC和MDA含量.结果 P1、P2不同剂量组的雄果蝇T-AOC较对照组均显著提高(P＜0.05),雌果蝇T-AOC虽提高,但为达到显著性水平.与对照组相比,P1组雌雄果蝇MDA含量明显降低(P＜0.05),P2组雄果蝇MDA含量明显降低(P＜0.05).结论 节旋藻藻胆蛋白具有增强雄果蝇T-AOC和降低果蝇体内MDA含量的作用.不同产地钝顶节旋藻的藻胆蛋白对果蝇T-AOC和MDA含量的影响不存在差异.     

脑神康胶囊对培养大鼠海马神经元缺氧复氧损伤的保护作用

目的 观察益气补肾中药脑神康胶囊对体外培养大鼠海马神经元缺氧复氧损伤的保护作用.方法 原代培养大鼠海马神经元,随机分为对照组,损伤组,脑神康胶囊高、中、低浓度组.对照组正常培养,损伤组及脑神康胶囊各浓度组建立缺氧复氧损伤模型,其中脑神康胶囊各浓度组于复氧时换以不同浓度(5%、10%、20%)含药血清的培养液,检测各组细胞超氧化物歧化酶(SOD)、乳酸脱氢酶(LDH)活力及丙二醛(MDA)含量,测定细胞存活率及凋亡率,RT-PCR法检测bcl-2 mRNA和bax mRNA的表达及两者比值.结果 与对照组比较,损伤组SOD活性及细胞存活率均明显下降(P＜0.01),MDA含量、LDH活力及细胞凋亡率均显著升高(P＜0.01),bcl-2 mRNA表达下降,bax mRNA表达升高,bcl-2/bax降低(均P＜0.01);脑神康胶囊各浓度组均较损伤组SOD活性及细胞存活率均升高(P＜0.01),MDA含量及细胞凋亡率均降低(P＜0.01),LDH活力及bax mRNA表达降低(P＜0.01,P＜0.05),bcl-2 mRNA表达升高,bcl-2/bax增加(均P＜0.01),且呈明显的剂量依赖性.结论 脑神康胶囊对海马神经元缺氧复氧损伤有明显的保护作用,其作用机制可能与其提高神经元抗氧化能力、调节凋亡相关蛋白、减少凋亡密切相关.     

川芎生物碱对大鼠血清中SOD活性、NO、NOS、MDA含量的影响

目的 研究川芎生物碱对局灶性脑缺血再灌注(I/R)大鼠血清中一氧化氮(NO)、一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量的影响.方法 取大鼠50只,随机分成5组,每组10只.即假手术组,I/R模型组,川芎碱低、中、高剂量治疗组.采用线栓法建立大鼠局造性脑I/R病理损伤模型[1].用黄嘌呤氧化酶法测定血浆中SOD活性;用硫代巴比妥酸显色法测定血浆中MDA含量;用NOS试剂盒测定NOS活性;硝酸还原酶法测定血清中NO含量.结果 I/R组与假手术组相比,血清中的SOD活性降低,MDA含量增加(P＜0.01),川芎碱低、中、高剂量治疗组与I/R组相比,血清中的SOD活性均升高,MDA含量均降低(P＜0.05).I/R组与假手术组相比,血清中NO含量升高,NOS活性增强(P＜0.01),川芎碱低、中、高剂量治疗组与IYR组比,NO含量均显著降低(P＜0.01).结论 川芎生物碱对脑I/R引发的自由基损伤有保护作用,从而减轻脑L/R后脑绢织的损害.     

人参糖肽对大鼠胰岛β细胞损伤的改善作用

目的探讨人参糖肽对链脲佐菌素(STZ)引起大鼠胰岛β细胞损伤的改善和防护作用。方法腹腔注射STZ损伤雄性Wistar大鼠胰岛为胰岛损伤组;注射STZ前连续7 d腹腔注射人参糖肽保护胰岛为人参糖肽组;以不经任何处理的大鼠为对照组。实验结束时采用放射免疫分析法检测大鼠血清胰岛素和C肽含量,苏木素-伊红(HE)染色观察胰岛病理改变,免疫组织化学染色检测胰岛素蛋白表达水平,电镜观察胰岛细胞超微结构变化。结果与对照组相比,胰岛损伤组大鼠血清胰岛素和C肽含量显著降低(P0.01),而人参糖肽组的血清胰岛素和C肽含量较胰岛损伤组明显升高(P0.01)。HE染色观察显示胰岛损伤组胰岛细胞数量显著减少,细胞排列不整,细胞肿胀,结构破坏,人参糖肽组的胰岛细胞损伤明显改善。免疫组织化学研究显示,胰岛损伤组胰岛素阳性染色面积明显缩小,而人参糖肽组的胰岛素阳性染色面积明显扩大(P0.01)。胰岛损伤组胰岛β细胞超微结构为变性-坏死性改变且分泌颗粒极少,而人参糖肽组胰岛β细胞变性-坏死性改变明显改善,分泌颗粒显著增多。结论人参糖肽能明显改善STZ引起的大鼠胰岛β细胞损伤。     

小檗碱对高脂高糖饮食与链脲佐菌素联合诱致糖尿病大鼠肾脏损伤的保护作用

目的探讨小檗碱对高脂高糖饮食与链脲佐菌素(STZ)联合诱致糖尿病大鼠肾脏损伤的保护作用及其机制。方法 SD大鼠70只,随机分为正常组和模型组。除正常组外,其余大鼠均给予高脂-高糖饲料喂养4 w,再给予STZ(40 mg/kg,ip),72 h后测定空腹血糖,将血糖值大于16.67 mmol/L的大鼠随机分为4组:模型组,二甲双胍组(250 mg/kg),小檗碱低剂量组(100 mg/kg)和高剂量组(200 mg/kg),连续给药8 w。末次给药后,收集24 h尿量,测定尿蛋白含量;取血测定血糖、血清胰岛素、糖化血红蛋白(HbA1c)含量、晚期糖基化产物(AGEs)含量、血肌酐、尿素氮等变化;测定肾组织AGEs和丙二醛(MDA)含量及超氧化物歧化酶(SOD)和Na-K-ATP酶活性;光镜下观察肾脏病理学变化。结果模型大鼠的空腹血糖(FBG)、胰岛素水平、HbA1c含量、血清和肾组织的AGEs含量均明显增高(P<0.01);尿蛋白量、血肌酐、尿素氮含量亦明显升高(P<0.01);肾组织MDA含量升高,SOD活性降低,Na-K-ATP酶活性减弱(P<0.01)。小檗碱低高剂量组治疗8 w后,明显改善FBG和胰岛素水平,降低HbA1c含量及血液和肾组织的AGEs含量(P<0.01,P<0.05);降低尿蛋白含量、血肌酐和尿素氮含量(P<0.05);减低肾组织MDA含量,提高SOD和Na-K-ATP酶活性(P<0.01,P<0.05)。结论小檗碱对高糖高脂饮食与STZ诱致糖尿病大鼠肾损伤具有保护作用,其机制可能与抑制糖基化反应及提高抗氧化作用有关。     

APP5肽类似物165对链脲佐菌素损伤SH-SY5Y细胞的保护作用

目的探讨体外APP5肽类似物165（下称P165）对链脲佐菌素（STZ）损伤SH-SY5Y细胞的保护作用。方法STZ0.8mmol/L作用于SH-SY5Y细胞的损伤模型。通过测定噻唑蓝（MTT）代谢率、乳酸脱氢酸（LDH）漏出率,瑞氏染色观察细胞形态,Western blot检测相关蛋白,观察P165的保护作用。结果与正常对照组细胞的MTT代谢率（1.00±0.01）和LDH漏出率（201.56±47.54）比较,STZ损伤组细胞MTT代谢率降低（0.84±0.01）,LDH漏出率升高（317.83±76.95）,差异有统计学意义（P〈0.05）,细胞胞体面积缩小,胰岛素信号通路相关蛋白IRS-1、PI3K表达减少;P16530μmol/L组细胞MTT代谢率升高（0.91±0.01）,LDH漏出率降低（228.53±35.65）,细胞形态恢复正常,胰岛素信号通路相关蛋白IRS-1、PI3K表达恢复正常。结论体外STZ与SH-SY5Y细胞共孵育,可能影响胰岛素/胰岛素受体信号转导系统对细胞的促生长作用,而P165可能通过激活该信号通路逆转这种损伤,可作为一种神经营养因子起到保护作用。     

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.     

MUTATION FREQUENCY IN NURSES AND PHARMACISTS WORKING WITH CYTOTOXIC DRUGS

Individuals occupationally exposed to cytotoxic drugs may be at risk owing to the effects of these agents on DNA. As an index of DNA damage, in vivo mutations were measured in lymphocytes from 24 oncology nurses or pharmacists and 24 matched controls. Mutation frequency was significantly increased in exposed individuals and appeared to be related to duration of exposure. However, the overall magnitude of the increase was small and its biological significance remains to be determined.