N-乙酰半胱氨酸对高血压大鼠心脏重构的影响

目的 探讨抗氧化剂N-乙酰半胱氨酸(NAC)对高血压大鼠心脏重构的影响及其作用机理.方法 结扎SD大鼠腹主动脉造成高血压模型,以NAC(75 mg/d)干预4周,测大鼠超声心动图、颈动脉血压、左室质量,观察心脏组织谷胱甘肽及基质金属蛋白酶2、9的分布,并观察心脏组织胶原含量的变化.结果 与手术组相比,试验组大收缩压明显降低[(161±6)vs(198±10)mm Hg,P＜0.05],左室收缩功能明显改善[EF(77.2±6.4)%vs(90.6±2.7)%,P＜0.05],谷胱甘肽在心肌组织中的含量显著增加,而左室质量及基质金属蛋白酶在心肌组织中的分布均有显著降低,心肌胶原含量明显减少.结论 NAC通过增加心肌组织还原型谷胱甘肽含量改善心肌组织氧化还原状态,从而减缓高血压大鼠心脏的进一步重构.     

骨髓干细胞移植通过基质金属蛋白酶及其抑制剂降低大鼠缺血性心力衰竭心室重构

目的探讨骨髓干细胞通过调节基质金属蛋白酶2/基质金属蛋白酶抑制剂1(MMP2/TIMP1)系统改善急性心肌梗死后心力衰竭心室重构。方法结扎雌性 SD 大鼠左冠状动脉制作急性心肌梗死模型。4周后随机分为2组:移植组大鼠7只,移植雄性 SD 大鼠来源的骨髓干细胞(5×10~6)到梗死后瘢痕区。对照组大鼠7只,移植等体积的 PBS 到瘢痕心肌。通过 HE 染色和 Masson 染色评价左室形态。免疫组织化学分析心肌 MMP2和 TIMP1和瘢痕区Ⅰ、Ⅲ型胶原表达情况。经Western 杂交检测 MMP2和 TIMP1蛋白变化。结果部分骨髓干细胞在移植后21天呈纤维母细胞样生长。移植后早期有炎症细胞聚集在瘢痕区,移植后7天炎症细胞减少。与对照组相比,移植组大鼠左室射血分数和左室短轴缩短率提高[(63.43±3.97)%与(36.20±3.99)%,(31.71±1.98)%与(18.00±2.07)%,P<0.05],左室压力下降最大值(dp/dt_(min))降低[(-4756.24±270.00)mm Hg/s(1 mm Hg=0.133 kPa)与(-2789.53±624.13)mm Hg/s,P<0.05],左室厚度率增加[(76.34±2.66)%与(64.37±2.36)%,P<0.05],梗死区面积缩小[(36.19±0.83)%与(42.12±1.88)%,P<0.05]。移植组大鼠瘢痕区Ⅰ型胶原表达升高,Ⅲ型胶原降低;心肌 MMP2蛋白水平降低而TIMP1水平升高。结论骨髓干细胞移植通过 MMP2/TIMP1导致胶原网络的动态变化,从而改善急性缺血后衰竭心脏的左室重构。     

氯沙坦对高血压大鼠心肌MMP-2、Ⅲ型胶原和JNK1/2表达的影响

目的研究Ⅲ型胶原、基质金属蛋白酶-2(matrix metalloproteinases-2, MMP-2)和JNK1/2在高血压大鼠心肌组织中的表达及氯沙坦干预后3者的变化,探讨氯沙坦逆转心室重构的药理机制.方法采用SD大鼠建立两肾一夹型(Goldblatt)高血压模型,将大鼠随机分为对照组、高血压组和氯沙坦治疗组.采用鼠尾动脉测压法记录每周血压变化,实验末切取心脏,并计算心脏与体重比值.免疫组织化学方法测定心脏组织中的Ⅲ型胶原、基质金属蛋白酶-2和JNK1/2表达.结果左肾动脉结扎术后大鼠收缩压升高,心脏体重比值增加,心肌间质Ⅲ型胶原、基质金属蛋白酶-2、心肌细胞JNK1/2表达增多.氯沙坦治疗能显著降低大鼠收缩压,降低心脏体重比值,并且使心肌间质Ⅲ型胶原、基质金属蛋白酶-2、心肌细胞JNK1/2表达减少.结论两肾一夹型高血压大鼠重构心肌中MMP-2、Ⅲ型胶原、JNK1/2表达升高.氯沙坦能有效逆转心肌肥厚或心室重构,这一效应与其降低心肌中高表达的MMP-2,Ⅲ型胶原、JNK1/2有关.     

氯沙坦对高血压大鼠心肌MMP-2、Ⅲ型胶原和JNK1／2表达的影响

目的研究Ⅲ型胶原、基质金属蛋白酶-2(matrix metalloproteinases-2，MMP-2)和JNK1／2在高血压大鼠心肌组织中的表达及氯沙坦干预后3者的变化，探讨氯沙坦逆转心室重构的药理机制。方法采用SD大鼠建立两肾一夹型(Goldblatt)高血压模型，将大鼠随机分为对照组、高血压组和氯沙坦治疗组。采用鼠尾动脉测压法记录每周血压变化，实验末切取心脏，并计算心脏与体重比值。免疫组织化学方法测定心脏组织中的Ⅲ型胶原、基质金属蛋白酶-2和JNK1／2表达。结果左肾动脉结扎术后大鼠收缩压升高，心脏体重比值增加，心肌间质Ⅲ型胶原、基质金属蛋白酶-2、心肌细胞JNK1／2表达增多。氯沙坦治疗能显著降低大鼠收缩压，降低心脏体重比值，并且使心肌间质Ⅲ型胶原、基质金属蛋白酶-2、心肌细胞JNK1／2表达减少。结论两肾一夹型高血压大鼠重构心肌中MMP-2、Ⅲ型胶原、JNK1／2表达升高。氯沙坦能有效逆转心肌肥厚或心室重构，这一效应与其降低心肌中高表达的MMP-2，Ⅲ型胶原、JNK1／2有关。     

心脏肥大细胞在自发性高血压大鼠心肌重构中的作用

目的探讨心脏肥大细胞在自发性高血压大鼠(SHR)心肌重构中的作用。方法应用病理检查、计算机分析结合逆转录聚合酶链式反应等方法,观察SHR及Wistar-Kyoto大鼠(WKY)收缩压、左室重量指数、心肌细胞直径、肥大细胞密度、心肌胶原容积分数(CVF)、心肌血管周围胶原面积比(PV-CA)和心肌Ⅰ、Ⅲ型胶原mRNA表达水平的变化。肥大细胞密度与左室重量指数、CVF及PVCA之间的关系采用相关分析。结果与WKY比较,SHR收缩压为(206±18)比(108±10)mm Hg(P<0.01);SHR组左室重量指数为(4.6±0.4)比(3.3±0.3)mg/g,(P<0.01);SHR组心肌细胞长径为(17.4±1.9)比(10.0±2.2)μm(P<0.01);SHR组心肌细胞短径为(9.0±2.0)比(5.8±1.7)μm(P<0.01);SHR组肥大细胞密度为(7.4±3.2)比(1.9±1.2)个/mm2(P<0.01),SHR组肥大细胞密度为WKY组的3.9倍。SHR组CVF、PVCA分别为46.4%±7.8%和1.9±0.9,WKY组分别为24.4%±10.7%和0.4±0.1,SHR组明显升高(P<0.01)。SHR组心肌Ⅰ、Ⅲ型胶原mRNA表达相对含量也均明显高于WKY(P<0.01),心脏肥大细胞密度与左室重量指数、CVF及PVCA存在明显的正相关(相关系数分别为0.67、0.87和0.95,P<0.01)。结论心脏肥大细胞密度增加可能是促进SHR心肌重构的重要原因。     

代谢综合征大鼠心脏PPARs变化与心脏重构和功能改变的关系

目的研究心脏过氧化物酶体增殖物激活受体(PPARs)变化与心脏重构和功能改变的关系。方法健康8周龄雄性Wistar大鼠,对照组(NC,n=10)和代谢综合征(MS)组(n=12),对照组予普食喂养,MS组予高脂(脂肪占总热能49%)高盐饮食,喂养24周。常规检测空腹血糖(FBG)、胰岛素(FINS)、血脂,葡萄糖耐量试验和高胰岛素正常血糖钳夹试验,并检测心肌组织的游离脂肪酸(FFA)水平。心脏重量和心脏组织形态学分析心脏结构改变,检测左室收缩末期压、左室舒张末期压(LVEDP)和左室压最大上升/下降速率(±dp/dtmax)了解心脏功能变化。心脏PPARα、PPARδ和PPARγ蛋白表达检测采用Westernblot方法。结果1.MS组大鼠心脏重量明显增加[(1.81±0.15vs1.36±0.06)g,P<0.05],心脏/体重比明显增高[(3.6±0.2vs3.2±0.1)mg/g,P<0.05],组织形态学显示心脏重构明显;2.MS组大鼠心功能参数-dp/dtmax明显低于NC组(4860±716vs6321±449)mmHg/s,而LVEDP明显增高[(3.5±0.7vs2.3±0.8)mmHg,P<0.05];3.MS大鼠心肌组织FFA水平明显增高[(0.26±0.09vs0.15±0.03)mmol/L,P<0.05];4.MS大鼠心脏PPARα、δ和γ蛋白表达明显减低;5.葡萄糖输注率(GIR)与心脏/体重比呈显著负相关(r=-0.77,P<0.05),心肌组织内FFA的水平与心功能参数-dp/dtmax呈显著负相关(r=-0.74,P<0.05)。结论MS大鼠心脏重构和功能失调明显,而心脏PPARs(PPARα、PPARδ、PPARγ)蛋白表达减低,可能对心肌脂肪酸代谢和MS有一定的影响,这可能是心脏重构和功能失调的原因之一。     

缬沙坦对压力超负荷兔心肌基质金属蛋白酶表达及胶原重构的影响

目的:观察缬沙坦对慢性压力超负荷兔左室肌基质金属蛋白酶-2,9(MMP2、MMP9)表达及胶原网络重构的影响,并探讨其机制。方法:36只家兔随机分为假手术组(12只)、结扎组(12只)、缬沙坦组(12只),腹主动脉次全结扎制备压力超负荷家兔模型。缬沙坦组给予缬沙坦(30mg·kg-1·d-1)灌胃,假手术组、结扎组给予等量的蒸馏水。术后12周取兔心肌行VG染色及免疫组化染色,观察胶原容积百分比(CVF)及MMP2、MMP9表达情况。结果:假手术组、结扎组、缬沙坦组MMP2的表达灰度值分别是(70.7±8.4)、(143.6±10.5)、(99.7±9.6),MMP9分别是(68.4±7.1)、(128.4±8.7)、(87.4±11.2);含小血管的CVF分别是(8.15±0.91)%、(17.72±0.64)%、(13.06±0.89)%。结论:基质金属蛋白酶是促使慢性压力超负荷下心肌胶原网络重构的重要因素,缬沙坦通过抑制基质金属蛋白酶能够改善胶原重构。     

Tribble 3在糖尿病心肌病心肌间质重构时的表达和缬沙坦干预的影响

目的探讨Tribble3(TRB3)基因在大鼠Ⅱ型糖尿病心肌病心肌间质重构中的可能作用及缬沙坦干预的影响。方法32只Wistar大鼠以高脂高热量饮食诱导加小剂量链脲佐菌素注射建立Ⅱ型糖尿病心肌病动物模型,随机分为糖尿病心肌病组和缬沙坦治疗组(缬沙坦30mg·kg-1·d-1灌胃),以8只正常大鼠作对照。采用Masson染色测定心肌胶原含量,实时定量逆转录-聚合酶链反应检测心肌TRB3mRNA表达。结果与对照组比较,糖尿病心肌病组左室心肌组织胶原含量显著高(11·01±3·05比16·92±3·18,P<0·01),与糖尿病心肌病组相比,缬沙坦组心肌胶原含量明显低(16·92±3·18比13·23±3·14,P<0·05),心肌组织胶原含量与空腹血糖呈明显正相关(r=0·746,P<0·01);与对照组相比,糖尿病心肌病组大鼠心肌TRB3mRNA表达水平明显高(0·0198±0·0082比0·1108±0·0933,P<0·05);与糖尿病心肌病组比较,缬沙坦组TRB3mRNA表达水平明显低(0·1108±0·0933比0·0367±0·0234,P<0·05);与对照组比较,缬沙坦组TRB3mRNA表达水平差异无统计学意义(P>0·05);糖尿病心肌病组大鼠心肌TRB3mRNA表达与血糖正相关(r=0·69,P<0·05),与心肌组织胶原含量正相关(r=0·67,P<0·05)。结论首次证实TRB3基因在大鼠心肌中表达,发现了TRB3基因可能参与了糖尿病心肌病心肌间质重构,缬沙坦干预减轻糖尿病心肌病心肌间质重构,改善左室舒张和收缩功能,下调TRB基因的表达。     

阿托伐他汀钙对肾血管性高血压大鼠模型左室重构的影响

目的观察阿托伐他汀钙对肾血管性高血压大鼠左室重构的保护作用。方法应用经典的两肾一夹方法,制备肾血管性高血压大鼠模型。实验动物随机分对照组(假手术)、高血压组及治疗组,每组各7只。治疗组给予阿托伐他汀钙(立普妥2 mg/kg)治疗6周。采用鼠尾测压法测定大鼠血压的变化;放射免疫分析法测定大鼠血浆血管紧张素(Ang)Ⅱ含量和肾素活性;称量法计算各组大鼠心脏重量及左室重量与体重比值。结果高血压大鼠血浆AngⅡ含量和肾素活性分别为(106.4±7.8)ng/L和(20.6±2.4)ng/L,比对照组〔(72.3±5.4)ng/L和(12.5±3.7)ng/L〕明显增高(P<0.01);心脏重量为(1.46±0.09)g,左室重量与体重比值为(3.54±0.19)×10-3,比对照组〔(0.98±0.07)g和(2.28±0.06)×10-3〕显著增大(P<0.01)。给予小剂量阿托伐他汀钙治疗6周后,AngⅡ含量〔(68.3±6.9)ng/L〕和肾素活性〔(8.7±2.3)ng/L〕明显下降(P<0.01),心脏重量减至(1.05±0.04)g,左室重量与体重比值降至(2.36±0.07)×10-3,与对照组比较差异无统计学意义(P>0.05)。结论阿托伐他汀钙能明显降低高血压大鼠心脏重量及左室重量与体重比值,对高血压大鼠病理性左室重构具有保护作用。     

基质金属蛋白酶-9在自发性高血压大鼠心室重构的变化及γ-干扰素的干预研究

目的:观察基质金属蛋白酶-9(MMP-9)在自发性高血压大鼠心室重构(SHR)的变化及γ-干扰素(IFN-γ)的干预作用。方法:28只SHR(雄性),随机分为4组(每组7只):高剂量组(SHR-H),中剂量组(SHR-M),低剂量组(SHR-L)和SHR对照组(SHR-C);另7只WKY大鼠(雄性),作为阴性对照组(WKY)。SHR-L组,SHR-M组,SHR-H组每日上午分别腹腔注射INF-γ,5万u/kg,10万u/kg,15万u/kg,连续8w。SHR-C组和WKY组每日上午腹腔注射等量的0.9%氯化钠液,连续8w。分别于治疗前,治疗后4w、8w,采用尾袖法测量尾动脉收缩压(SBP),ELISA法检测血清MMP-9含量。实验第8周,处死大鼠,称取左心室质量(LVM),计算左心室质量指数LVMI(LVWI=LVM/BW);光镜下观察HE染色的心肌组织;采用werstern blot法检测心肌组织MMP-9蛋白表达。结果:各SHR组尾动脉收缩压(SBP)、左心室质量、LVMI及MMP-9的血清水平较WKY组明显升高(P<0.0 5)。应用IFN-γ后,治疗组的各指标较SHR-C均显著下降SBP[(189.57±5.06)vs.(201.57±5.74)mmHg(1 mmHg=0.133kPa)],LVMI[(2.68±0.08)vs.(2.89±0.08)mg/g],MMP-9[(3.20±0.35)vs.(4.90±0.51)mg/L,P<0.05)];心肌组织MMP-9蛋白明显负调表达[(0.49±0.07)vs.(1.05±0.08),P<0.05]。结论:IFN-γ能抑制心肌组织中MMP-9表达,改善高血压心室重构,可能与抑制心肌的慢性炎症有关。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.