U69 593对家兔心室肌细胞L型Ca2+电流的影响

目的 :研究 U695 93对家兔心室肌细胞 L 型 Ca2 +电流 （ ICa· L）的影响。方法 :采用全细胞膜片钳技术记录家兔心室肌细胞 IC a· L。结果 :在 -2 0～ +4 0 m V测试电压范围内 ,10 0 nmol/ L U695 93显著增加 IC a· L,以 +10 m V为最大激活电压 ,其峰值 ICa· L由加药前 -7.1± 0 .4p A/ p F增至 -8.3± 0 .5 p A/ p F （ P<0 .0 1,n=8）。 10 0 nmol/ LU 695 93不影响 IC a· L电压依赖性激活与失活特性。结论 :U695 93可增加家兔心室肌细胞 ICa· L。     

雌激素抑制大鼠心室肌细胞L-型钙电流机制的研究

目的 :探讨雌激素抑制大鼠心肌细胞 L -型钙电流 （ICa,L）的可能途径。方法 :通过胶原酶消化得到单个大鼠心室肌细胞 ,膜片钳全细胞电压钳方法记录 ICa,L。结果 :雌激素 （1～ 30μmol/ L ）可剂量依赖性地抑制 ICa,L,雌激素对ICa,L的抑制作用并不能被雌激素受体的阻断剂 Tamoxifen和 ICI 182 780所阻断。细胞外灌流耦联了牛血清白蛋白（BSA）的雌激素 [β- estradiol6 - （o- carboxy- m ethyl） oxime:BSA（EST- BSA） ],不能透过细胞膜 ]也能抑制 ICa,L,但同样浓度的 EST- BSA细胞内灌流对 ICa,L并没有明显的抑制作用。结论 :雌激素可能是通过膜表面上特异的受体介导了其对 L-型钙电流的抑制作用     

黄芪总黄酮对急性心肌梗死大鼠心室肌细胞L-型钙电流及钠电流的作用

目的研究黄芪总黄酮（TFA）对急性心肌梗死（Am）大鼠心室肌细胞L-型钙电流（L—ICa）及钠电流（INa）的作用。方法设正常对照组、AMI组及TFA实验组。大鼠开胸左前降支结扎造成AMI,开胸前5min实验组大鼠舌静脉注射剂量为20mg／kg的TFA溶液50ul。用胶原酶酶解法急性分离AMI模型大鼠心室肌细胞,采用全细胞膜片钳记录技术记录左前降支供血区心外膜细胞的L—ICa及INa的作用。结果①应用TFA（20mg／kg）后,L—ICa从（0．313±0．14）nA增加到（0．402±0．27）nA,差异有统计学意义（P〈0．01,n=6）。②应用TFA（20mg／kg）后与对照组比较,峰值从（-8．43±2,03）nA下降到（-6．37±1．58）nA,差异有统计学意义（P〈0．01,n=6）。结论TFA可以增加AMI大鼠心室肌细胞L—ICa的幅值,TFA可显著降低AMI大鼠心室肌细胞INa的幅值。     

胡椒碱对H2O2致兔心房肌细胞动作电位时程及L型钙电流异常的保护作用

目的:研究胡椒碱(PIP)对H2O2引起的单个兔心房肌细胞动作电位时程（APD）及L型钙电流(ICa,L)异常的保护作用。方法:采用全细胞膜片钳技术,观察10和50 μmol/L的H2O2引起单个兔心房肌细胞APD及ICa,L的改变,以及预先应用7 μmol/L的PIP对其的作用。结果:7 μmol/L的PIP对正常兔心房肌细胞APD、ICa,L及L型钙通道动力学无明显影响。在10和50 μmol/L的H2O2作用下,兔心房肌细胞APD50和APD90明显缩短(P<0.05),静息膜电位（RMP）绝对值显著下降(P<0.05),ICa,L峰值由(39.3±5.4) pA/pF降低至(32.8±2.0) pA/pF(P<0.05),电流-电压曲线上移,通道稳态激活曲线右移,通道稳态失活曲线左移,但恢复时间不变。预先给予7 μmol/L的PIP可明显减轻H2O2对APD、ICa,L的抑制作用(P<0.01),对L型钙通道动力学的异常影响。结论:PIP可减轻氧化应激对心房肌细胞APD、ICa,L的影响。     

大蒜素对自发性高血压大鼠肠系膜动脉平滑肌细胞钙电流的作用

目的:观察大蒜素(Gar)对自发性高血压大鼠(SHR)肠系膜动脉平滑肌细胞L-型钙电流(LCa,L)的影响。方法:利用双酶-两步法消化得到单个大鼠肠系膜动脉血管平滑肌细胞,用全细胞膜片钳记录钙电流。在细胞池中灌流含Gar的细胞外液,观察药物对LCa,L的作用和门控机制及门控动力学参数的改变。结果:1Gar对ICa,L的抑制效应呈浓度依赖性和电压依赖性特征。刺激电位0 mV时,200μmol/L Gar可使ICa,L峰值密度由(-8.4±0.4)pA/pF降低为(-6.1±0.3)pA/pF;2药物可使ICa,L半激活电压V1/2右移,半失活电压左移及失活后恢复动力学减慢等环节可减少通道的开放和重复开放,从而减少ICa,L峰值密度和窗口电流。结论:Gar可能通过减少细胞的钙电流发挥降压效应。     

乙酰胆碱诱发的豚鼠心室肌反跳作用研究

观察乙酰胆碱 (ACh)诱发的豚鼠心室肌肌力及钙电流的反跳作用 ,并探讨其作用机制。采用豚鼠离体左室乳头肌观察 1μmol/LACh单独对心室肌收缩力 (Fc)的影响及在 10nmol/L异丙肾上腺素 (Iso)存在时对Fc的影响 ,并应用膜片钳全细胞记录方法分别观察 1μmol/LACh和 1μmol/LACh +10nmol/LIso及迅速洗脱ACh对豚鼠心室肌细胞L型钙通道电流 (ICa L)的影响。结果 :1μmol/LACh对心室肌Fc有直接抑制作用 ,抑制率为 30 .8%± 10 .7%(P <0 .0 5 ) ,而快速洗脱ACh后 ,Fc反跳性增强了 2 5 .5 %± 10 .3% (n =7,P <0 .0 1)。而在应用 10nmol/LIso后 1μmol/LACh对Fc有间接的抑制作用 ,快速冲洗ACh后亦引起Fc的反跳性增强 ,与Iso组相比增强了 2 7.1%±13.2 % (n =7,P <0 .0 1)。 1μmol/LACh对心室肌细胞基础峰电流无明显影响 (n =8,P >0 .0 5 ) ;而以基础ICa L峰值(931± 16 1pA)作对照 ,在加入 10nmol/LIso后 ,ICa L峰电流增强到 1889± 331pA(n =7,P <0 .0 1) ;再给予 10nmol/LIso +1μmol/LACh快速灌流 2min ,峰电流降低为 15 12± 2 0 2pA(P <0 .0 1) ,用含 10nmol/LIso的细胞外液快速洗脱ACh ,峰电流增强到 2 10 7± 2 0 5pA ,较Iso组反跳性增强了 15 .8%± 4 .0 % (n =7,P <0 .0 1)。结论 :ACh对豚鼠心室肌收缩     

氧化苯胂对大鼠心室肌细胞L型Ca2+电流的影响

目的 :探讨氧化苯胂 （PAO） ,一种膜可通透的酪氨酸磷酸酶抑制剂 ,对大鼠心室肌细胞 L型 Ca2 +电流 （ICa,L）的影响。方法 :采用全细胞膜片钳技术记录大鼠心室肌细胞 ICa,L。结果 :1PAO对基础 ICa,L及β-肾上腺素受体激动剂异丙肾上腺素 （Iso）激发的 ICa,L有抑制作用 ;2 PAO对腺苷酸环化酶激动剂 forskolin激发的 ICa,L亦有抑制作用 ;3电极内液加入 1.5 mm ol/ L矾酸钠不能消除 PAO的作用 ;4PAO对 ICa,L的抑制作用可被二硫代苏糖醇反转。结论 :PAO抑制 ICa,L的作用与 c AMP- PKA-磷酸化途径和酪氨酸磷酸酶无关 ,可能与其使 L 型 Ca2 +通道蛋白上巯基氧化有关。     

乙酰胆碱对离体豚鼠心室肌的直接作用机制探讨

目的 :研究乙酰胆碱 （ACh）对离体豚鼠心室肌的直接负性作用及机制。方法 :采用标准玻璃微电极细胞内记录技术记录动作电位 （AP）及肌力换能器记录心肌收缩力 （FC）的方法观察 ACh对离体豚鼠心室肌的作用 ,并观察几种受体或通道水平的阻断剂阿托品、氯化铯 （Cs Cl）、氯化镉 （Cd Cl2 ）对 ACh直接作用的影响。结果 :10 - 5 mol/LACh对心室肌动作电位持续时间 （APD）及 FC的抑制率分别为 7.31%和 37.5 7% （P<0 .0 5 ） ,10 - 5 mol/L阿托品和 2 0 m mol/L Cs Cl可阻断该作用 ,0 .1m mol/L Cd Cl2 对该作用无影响。结论 :10 - 5 m ol/L ACh对离体豚鼠心室肌有直接负性作用 ,ACh的作用与毒蕈碱型胆碱受体及 K+电流有关 ,而与 Ca2 +电流的关系可能不大。     

酸氟西汀致严重低血钠症1例

患者男 ,70岁。因嗜睡、呼吸困难入院。患者因高血压长期服用双氢克尿噻及美多心安。近 2 0天由于抑郁加服盐酸氟西汀2 0 m g,每日 1次。半个月前数次检查血电解质均在正常范围。体检 :体温 36 .7℃ ,心率 75次 /m in,血压 15 0 /90 mm Hg;精神萎靡 ,双肺布满干罗音 ,无周围性肿。实验室检查 :血钠 10 9m mol/L,尿渗透压为 2 10 m Osm /kg,血浆渗透压 2 35 m Osm/kg,尿钠42 m mol/L。诊断为低钠血症。入院后嘱其停用所有药物 ,静脉给予生理盐水及速尿治疗。 5天后血钠恢复正常。讨论 :本例长期应用抗高血压药 ,血钠水平基本正常。服用盐酸…     

心肌肽素对急性心肌梗死大鼠心脏血流动力学及心肌细胞钙电流的作用

目的探讨心肌肽素（cardiomyopeptidi）对急性心肌梗死（AMI）大鼠心脏血流动力学及心肌细胞钙电流的作用。方法大鼠开胸左前降支结扎造成AMI。开胸前5min实验组大鼠舌静脉注射浓度为50μg／ml的心肌肽素溶液50μl,并设正常对照组、AMI组及心肌肽素实验组,行血流动力学检查;酶解分离心室肌细胞,采用全细胞膜片钳记录技术记录左前降支供血区心外膜细胞的L型Ca^2＋电流（L—Ica）的作用。结果应用心肌肽素（50p,g／m1）后与AMI组比较,血流动力学指标明显改善（P〈0．05,n=7）。②应用心肌肽素（50μg／m1）后,L-型钙电流（L—ICa）由给药前的（0．15±0．34）nA增加到给药后的（0．31±0．37）nA（P〈0．01,n=7）。结论心肌肽素可以明显改善AMI大鼠心脏血流动力学,可以增加AMI大鼠心室肌细胞L-型钙电流的幅值。     

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.     

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.     

N-acetyl-L-cysteine combined with mesalamine in the treatment of ulcerative colitis： Randomized,placebo-controlled pilot study

AIM： To evaluate the effectiveness and safety of oral N-acetyl-L-cysteine （NAC） co-administration with mesalamine in ulcerative colitis （UC） patients.
METHODS： Thirty seven patients with mild to moderate UC were randomized to receive a four-wk course of oral mesalamine （2.4 g/d） plus N-acetyl-L-cysteine （0.8 g/d） （group A） or mesalamine plus placebo （group B）. Patients were monitored using the Modified Truelove-Witts Severity Index （MTWSI）. The primary endpoint was clinical remission （MTWSI ≤ 2） at 4 wk. Secondary endpoints were clinical response （defined as a reduction from baseline in the MTWSI of ≥ 2 points） and drug safety. The serum TNF-α, interleukin-6, interleukin-8 and MCP-1 were evaluated at baseline and at 4 wk of treatment. RESULTS： Analysis per-protocol criteria showed clinical remission rates of 63% and 50% after 4 wk treatment with mesalamine plus N-acetyl-L-cysteine （group A） and mesalamine plus placebo （group B） respectively （OR = 1.71; 95% CI： 0.46 to 6.36; P = 0.19; NNT = 7.7）. Analysis of variance （ANOVA） of data indicated a significant reduction of MTWSI in group A （P = 0.046） with respect to basal condition without significant changes in the group B （P = 0.735） during treatment. Clinical responses were 66% （group A） vs 44% （group B） after 4 wk of treatment （OR = 2.5; 95% CI： 0.64 to 9.65; P = 0.11; NNT = 4.5）. Clinical improvement in group A correlated with a decrease of IL-8 and MCP-1. Rates of adverse events did not differ significantly between both groups.
CONCLUSION： In group A （oral NAC combined with mesalamine） contrarily to group B （mesalamine alone）, the clinical improvement correlates with a decrease of chemokines such as MCP-1 and IL-8. NAC addition not produced any side effects.     

Delorme's transrectal excision for internal rectal prolapse

Surgical therapy of functional outlet obstruction in patients with internal rectal intussusception may include abdominal, perineal, or transrectal procedures. Because abdominal procedures often result in significant physiologic impact but unrelieved constipation, the authors have elected Delorme's transrectal excision for management of these patients. Since a short-term placebo effect attends many therapies, this report describes results of transrectal excision only after a threeyear postoperative period. Delorme's transrectal excision of internal intussusception accomplished sustained symptomatic relief in over 70 percent of otherwise refractory constipated patients. The association of internal intussusception with other abnormalities underscores the importance of defining both anatomic and functional components when selecting patients whose constipation may require surgical therapy. Critical technical elements, surgical pitfalls, and potential complications of the procedure are discussed.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Toronto, Canada, June 11 to 16, 1989.     

The oral glucose tolerance test: A comparison of the time points on the basis of limit values,normal dispersion,and reproducibility

Summary Time points in the glucose tolerance test (GTT) are compared on the basis of limit values, dispersion within a reference population, and reproducibility. We suggest using the distance between a limit value and the median reference value as a measure of the magnitude of abnormality. The distance between 140 mg/100 ml and the median fasting plasma glucose value is chosen as a standard distance and limits for other points in the GTT are calculated to equal this standard distance of abnormality. We suggest that the probability of correctly interpreting an inividual result is directly related to the reproducibility of the test and inversely related to the percentage of the total range of values which is dispersed among the normal population. The ratio of reproducibility to percentage normal dispersion is proposed as an index of the probability of correctly interpreting an individual result. According to this index, the probability of correct interpretation varies in order: fasting plasma glucose concentration>3-h>2-h>0.5-h>1-h plasma glucose concentration.