雌激素抑制血管平滑肌细胞增殖和胶原合成的实验研究

目的　探讨雌激素对于胎儿血管平滑肌细胞 (HVSMC)增殖和胶原合成的影响。方法　分别以不同浓度 (0 .1nmol/ L～ 10 0 nm ol/ L)的雌二醇作用于体外培养的 HVSMC,利用 3H-脯氨酸掺入法测定培养平滑肌细胞胶原合成及 3H- Td R掺入法测定细胞增殖率。结果　 1.0 nm ol/ L～ 10 0 nmol/ L 雌激素以剂量依赖性方式抑制 10 %胎牛血清诱导 HVSMC增殖和胶原合成。结论　小剂量雌二醇具有抗动脉粥样硬化作用 ,而超生理剂量雌二醇可能诱发血管损伤     

不同砷化物对原代培养星型胶质细胞毒性作用的研究

目的 观察不同砷化物对原代培养星型胶质细胞的毒性作用。方法 细胞活力检测与形态学观察。结果 暴露40、60、80、100μmol／L3价和200、300、400、500μmol／L 5价无机砷的星型胶质细胞的AlamarBlue还原力与对照组比较差异有显著意义，且呈剂量-效应关系。体外24h暴露iAs^v和iAs^Ⅲ对原代培养星形胶质细胞的半数细胞活力抑制浓度分别为260．3μmol／L和50．8μmol／L。同时，暴露最低25μmol／L3价和100μmol／L5价无机砷的星型胶质细胞的细胞形态有明显的改变。另一方面，暴露最高1000μmol／L5价甲基砷和二甲基砷的星型胶质细胞的AlamarBlue还原力及细胞形态与对照组比较未见明显差异。结论 接触最少25μmol／L的3价无机砷或100μmol／L的5价无机砷对星型胶质细胞可产生明显的毒性损伤作用。3价无机砷的毒性明显大于5价无机砷。在微摩尔浓度范围内的5价甲基砷和二甲基砷对原代培养的星型胶质细胞无明显的直接毒性作用。     

亚砷酸钠诱导人膀胱上皮永生化细胞氧化损伤作用观察

目的 观察亚砷酸钠(NaAsO2)诱导人膀胱上皮永生化细胞(SV-HUC-1)氧化损伤作用.方法 以不同浓度NaAsO2[0(对照)、1、2、4、8、10μmol/L]对SV-HUC-1细胞染砷24 h,利用流式细胞仪检测细胞内活性氧(ROS)水平,采用酶联免疫吸附实验(EHSA法)检测细胞内硝基酪氨酸(NT)含量和细胞培养液中8-羟基脱氧鸟嘌呤核苷(8-OHdG)水平.结果 1、2、4、8、10 μmol/L染砷组SV-HUC-1细胞ROS水平(81.76±4.91、95.23±2.17、126.61±17.95、126.74±27.77、114.18±9.65)明显高于对照组(69.84±1.28,P＜ 0.05或＜ 0.01),ROS水平与染砷剂量呈显著正相关(r=0.818,P＜ 0.01).10 μmol/L染砷组SV-HUC-1细胞内NT含量[ (919.66±206.33)μg/L]显著高于对照组[(238.19±38.28) μg/L,P＜ 0.01],NT含量与染砷剂量呈显著正相关(r=0.617,P＜0.01).各组细胞培养液中8-OHdG含量比较,差异无统计学意义(F=2.127,P＞0.05).结论 NaAsO2能够引起SV-HUC-1细胞氧化损伤.     

三氧化二砷体外对人卵巢上皮癌细胞3AO增殖及凋亡的影响

目的　探讨三氧化二砷 (As2 O3 )体外对人卵巢上皮癌细胞株 3AO增殖和凋亡的影响及其作用机制。方法　将人卵巢上皮癌细胞株 3AO与不同浓度的As2 O3 进行体外培养 ,采用四甲基偶氮唑蓝(MTT)测定不同浓度As2 O3 对 3AO细胞的生长抑制率 ,采用流式细胞技术检测细胞凋亡率、细胞周期时相及其Fas、FasL、P53 和bcl 2蛋白的表达。结果　 0 2 5～ 8 0 μmol /L浓度的As2 O3 均显著抑制3AO细胞的增殖 ,且随浓度升高及作用时间的延长 ,抑制率上升 ,As2 O3 与 3AO细胞联合培养 4 8小时的半数致死量 (IC50 )为 (3 90± 0 2 0 ) μmol /L。 0 2 5～ 4 0 μmol /L浓度的As2 O3 均诱导 3AO细胞凋亡 ,随浓度升高 ,凋亡率上升。As2 O3 阻滞 3AO细胞停滞于S期 ,并诱导细胞凋亡。As2 O3 (2 μmol/L )培养3AO细胞 4 8小时 ,Fas蛋白表达率为 (4 6 76± 4 5 0 ) % ,明显高于对照组的 (6 36± 0 82 ) % ,差异有显著性(P <0 0 5 ) ,FasL、P53 和bcl 2蛋白表达无明显变化 (P >0 0 5 )。结论　As2 O3 以剂量 时间依赖性方式抑制人卵巢上皮癌细胞 3AO增殖并诱导其凋亡 ,其作用机制与上调Fas基因表达有关。     

钙通道阻滞剂对体外培养神经瘢痕成纤维细胞形态及胶原分泌的影响

目的 观察钙通道阻滞剂对体外培养神经瘢痕成纤维细胞形态及胶原分泌的影响.方法 SD大鼠10只,制作双侧坐骨神经损伤模型,术后2 w取损伤处神经瘢痕,按组织块法培养神经瘢痕成纤维细胞,实验所用细胞为4～8代,分4组,T50、T100、T200组分别含维拉帕米50、100及200 μmol/L,C组为空白对照组,分别进行Giemsa染色和羟脯氨酸比色法测定细胞上清液中的胶原含量和胞浆中的胶原含量,并进行统计学分析.结果 维拉帕米可以改变神经瘢痕成纤维细胞的形态,即趋于球形变,使分泌到细胞培养上清中的胶原含量明显减少,胞浆中的胶原含量增加,具有明显剂量依赖性,以200 μmol/L浓度组作用最为显著(P＜0.05).结论 维拉帕米可使成纤维细胞趋于球形变,减少胶原蛋白分泌到细胞外,其效应在一定范围内呈剂量依赖性.     

氟对成纤维细胞增殖活性影响的剂量-效应关系

目的观察不同质量浓度氟在不同时间段对小鼠皮肤成纤维细胞株(L929)增殖活力的影响。方法采用四唑盐(MTT)比色法,观察氟对培养的小鼠皮肤成纤维细胞增殖活力的影响。结果0.001、0.002mg/L氟作用1h、0.001mg/L氟作用2h,可使成纤维细胞增殖活力较对照组明显增强。随着氟质量浓度的增加和氟作用时间的延长,成纤维细胞的增殖活力明显减弱。结论氟在一定剂量范围内对成纤维细胞的增殖活力有刺激作用,这种作用亦受作用时间的影响。     

H2O2诱导体外培养的皮肤成纤维细胞氧化应激损伤

目的探讨H2O2对体外培养的人皮肤成纤维细胞生物学特性的影响,从细胞水平为抗皮肤衰老药物的研究提供较理想的皮肤衰老模型。方法用不同浓度的H2O2(50～300μmol/L)干预体外培养的正常皮肤成纤维细胞,MTT比色法检测细胞增殖,流式细胞仪检测细胞凋亡,羟脯氨酸比色法检测胶原含量,紫外分光光度计测定细胞中超氧化物歧化酶(SOD)的活性和丙二醛(MDA)的含量。结果 H2O2浓度依赖性地抑制皮肤成纤维细胞增殖,促进细胞凋亡,降低细胞SOD的活性,减少细胞胶原含量,增加MDA含量。结论氧化应激可损伤皮肤成纤维细胞,用H2O2致皮肤成纤维细胞氧化损伤模型可用于抗皮肤衰老药物的研究。     

EGFR抑制剂AG1478对胶质瘤C6细胞增殖及凋亡的影响

[目的]观察表皮生长因子受体(EGFR)抑制剂AG1478对胶质瘤C6细胞增殖和凋亡的影响.[方法]C6细胞中分别加入5、10、25、50 mol/L的AG1478,作用48 h.用MTT法测算C6细胞生长抑制率,倒置显微镜观察细胞形态学的改变,流式细胞术测算细胞凋亡率.[结果]AG1487能够抑制C6细胞的增殖,其抑制作用呈剂量—效应依赖关系.在50 μmol/L的AGI478作用下,C6细胞变圆、细胞突起减少,贴壁瘤细胞数量明显减少,排列稀疏.25 μmol/L的AG1478作用C6细胞48h,细胞凋亡率显著增加.[结论]EGFR抑制剂AG1478可抑制胶质瘤C6细胞的增殖,促进细胞凋亡.     

无机砷对Chang liver细胞血红素单加氧酶-1表达的活化作用

目的 观察无机砷(NaAsO2)对正常人肝细胞株Changliver细胞血红素单加氧酶-1(heme oxygenase-1,HO-1)表达的活化作用.方法 采用细胞培养的方法,将Chang liver细胞分别暴露于10 μmol/L NaAsO2后0(对照)、2、6、12、24 h和0(对照)、5、10、25、50 μmol/L后12 h,收集细胞,Western blot技术检测细胞内HO-1蛋白的表达.结果 Chang liver细胞染砷10 μmol/L.体外培养6、12、24 h,细胞内HO-1蛋白表达(3.97±0.72、12.92±2.98、23.29±3.82)明显高于对照组(1.00±0.00).组问比较和各组分别与对照组比较.差异有统计学意义(F=85.83,P＜0.01;t值分别为-9.42、-8.95、-13.83,P＜0.05或＜0.01).染砷5、10、25、50 μmo]/L.体外培养12 h,细胞内HO-1蛋白表达(6.34±0.25、7.75±0.39、7.93±0.14、12.48±-0.35)明显高于对照组(1.00±0.00),组间比较和各组分别与对照组比较,差异有统计学意义(F=709.66,P＜0.01;t值分别为-36.25、-30.19、-86.40、-56.40,P＜0.01).结论 无机砷能够诱导Chang Liver细胞内HO-1的活化,促进蛋白表达,并且具有时间和剂量效应.     

氟砷单独及联合作用对正常人淋巴细胞增殖的影响观察

目的观察氟、砷单独及联合作用对正常人淋巴细胞增殖的影响.方法采用MTT实验测定亚砷酸钠及氟化钠对正常人淋巴细胞的LC50,然后以此为依据制定试验剂量(LC50的1/100～1/10),观察低剂量氟、砷单独及联合作用对正常人淋巴细胞增殖的影响.结果人淋巴细胞在经浓度为0.1,1μmol/L的NaAsO2及浓度为50mol/L的NaF染毒后,其MTT吸光度值与对照组相比,均呈下降趋势,且有统计学意义(P均＜0.01).结论氟砷联合作用对人淋巴细胞生长表现出明显的抑制作用,但经交互作用方差分析,尚不能认为氟砷联合作用对人淋巴细胞生长的抑制有交互作用(P＞0.05),低剂量亚砷酸钠及氟化钠对人淋巴细胞均存在明显的毒作用;氟与砷之间对人淋巴细胞的生长抑制作用并没有交互作用,仅表现为简单的相加作用.     

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.