高棕榈酸饮食对ApoE基因敲除小鼠动脉粥样硬化的影响

1目的：观察高棕榈酸饮食对载脂蛋白E（ApoE）基因敲除小鼠的血脂、血浆游离脂肪酸水平、动脉粥样硬化斑块面积、斑块中胶原含量和基质金属蛋白酶2表达的影响。方法：将20只6～8周龄雄性ApoE基因敲除小鼠随机分为对照组和高棕榈酸饮食组,每组10只。分别给予普通小鼠饲料和含5％棕榈酸的饮食,连续喂养12周。用比色法检测血脂和血浆游离脂肪酸水平;主动脉根部连续石蜡切片,Masson染色检测斑块内胶原含量,免疫组化法检测主动脉基质金属蛋白酶2的表达。结果：两组血脂水平无明显差异。与对照组相比,高棕榈酸饮食组血浆游离脂肪酸水平显著升高,主动脉斑块内胶原含量显著降低,主动脉基质金属蛋白酶2表达明显增加（P均〈0．05）。结论：高棕榈酸饮食能够升高血浆游离脂肪酸水平,降低斑块内胶原含量,从而降低动脉粥样硬化斑块稳定性,其机制可能与其上调基质金属蛋白酶2的表达有关。     

红景天甙对低压低氧诱导的ApoE-/-小鼠动脉粥样硬化斑块稳定性的影响

目的:观察红景天甙对间歇性低压低氧诱导的载脂蛋白E基因敲除(ApoE-/-)小鼠动脉粥样硬化斑块稳定性的影响。方法:30只8周龄健康雄性ApoE-/-小鼠随机分为常压常氧组(对照组)、间歇性低压低氧组(低压低氧组)、低压低氧+红景天甙组(干预组),其中低压低氧组和干预组被放置在模拟海拔5 000m低压低氧舱内每天8h,每组给予相同的普通饮食喂养,干预组灌服红景天甙30mg·kg-1·d-1,而对照组和低压低氧组灌服等量蒸馏水。连续灌胃12周后取小鼠血样测空腹血糖及血脂,取小鼠主动脉根部的主动脉,Masson染色观察动脉粥样硬化斑块的大小及斑块内的胶原纤维含量,免疫组织化学染色检测基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶-9(MMP-9)及基质金属蛋白酶组织抑制剂-2(TIMP-2)蛋白的表达情况。结果:3组空腹血糖和血脂水平差异无统计学意义;与对照组比较,低压低氧组的动脉粥样硬化斑块面积明显增加,胶原含量明显减少(均P0.01);与低压低氧组比较,红景天甙干预组斑块面积及MMP-2、MMP-9蛋白水平明显降低,而斑块胶原含量及TIMP-2蛋白水平明显增加(均P0.01)。结论:红景天甙能抑制间歇性低压低氧诱导的动脉粥样硬化斑块形成,并提高斑块的稳定性,其机制可能与红景天甙增加斑块内胶原含量和降低MMP-2、MMP-9,提高TIMP-2蛋白的表达有关。     

红景天甙对间歇性低压低氧诱导的ApoE－/－小鼠动脉粥样硬化的影响

目的　观察红景天甙对间歇性低压低氧诱导的载脂蛋白E基因敲除（ApoE^－/－）小鼠动脉粥样硬化的影响及其可能机制。方法　30只8周龄健康雄性ApoE^－/－小鼠随机分为常压常氧组、间歇性低压低氧组、低压低氧＋红景天甙组,其中间歇性低压低氧组和低压低氧＋红景天甙组被放置在模拟海拔5000　m低压低氧舱内每天8　h,每组给予相同的普通饮食喂养,低压低氧＋红景天甙组灌服红景天甙30　mg/（kg·d）,而常压常氧组和间歇性低压低氧组灌服等量蒸馏水,连续灌胃12周后取小鼠血样测空腹血糖和血脂,取小鼠主动脉根部,HE染色观察动脉粥样硬化斑块的大小,Masson染色观察斑块内胶原含量,Western　blot检测基质金属蛋白酶2（MMP-2）、基质金属蛋白酶9（MMP-9）和组织型基质金属蛋白酶抑制剂2（TIMP-2）蛋白的表达。结果　三组空腹血糖和血脂水平无统计学差异（P>0.05）;与常压常氧组比较,间歇性低压低氧组动脉粥样硬化斑块面积明显增加（P<0.01）,胶原含量明显减少（P<0.01）;与间歇性低压低氧组比较,低压低氧＋红景天甙组斑块面积、MMP-2和MMP-9蛋白水平明显降低（P<0.01）,而斑块内胶原含量、TIMP-2蛋白水平明显增加（P<0.01）。结论　红景天甙能抑制间歇性低压低氧诱导的动脉粥样硬化斑块形成,并提高斑块的稳定性,其机制可能与红景天甙增加斑块内胶原含量有关。     

间歇性低压低氧促进载脂蛋白E基因敲除小鼠血管重构

目的　探讨高海拔间歇性低压低氧（IHH）环境对载脂蛋白E基因敲除（ApoE^－/－）小鼠血管重构的影响。方法　将14只8周龄雌性ApoE^－/－小鼠随机分为对照组和IHH组,IHH组每天在低压舱模拟的4000　m海拔低压低氧环境中放置8　h,持续60天。干预完成后采用Masson染色测定胸主动脉管壁胶原含量,采用免疫组织化学法检测基质金属蛋白酶（MMP）及其组织型基质金属蛋白酶抑制剂（TIMP）的表达情况。结果　与对照组比较,间歇性低压低氧组小鼠主动脉管壁胶原含量显著降低,MMP-9的表达显著增高,而TIMP-2的表达显著降低（P＜0.01）,而MMP-2、MMP-14在两组间没有显著差异（P＞0.05）。结论　IHH可能通过加重ApoE^－/－小鼠血管壁MMP-9和TIMP-2的表达失衡减少血管壁胶原含量,从而促进血管重构。     

血管紧张素Ⅱ对载脂蛋白E敲除小鼠主动脉粥样硬化斑块细胞外基质金属蛋白酶诱导因子表达影响

目的探讨血管紧张素Ⅱ对载脂蛋白E敲除小鼠主动脉粥样硬化斑块细胞外基质金属蛋白酶诱导因子表达的影响。方法载脂蛋白E基因敲除小鼠经高脂饮食饲养建立动脉粥样硬化模型,用血管紧张素Ⅱ干预。用免疫组织化学法观察粥样硬化斑块内细胞外基质金属蛋白酶诱导因子表达,用RT-PCR及Western blotting检测主动脉内细胞外基质金属蛋白酶诱导因子表达。结果血管紧张素Ⅱ干预组细胞外基质金属蛋白酶诱导因子在动脉粥样硬化斑块内阳性表达较对照组明显增加;血管紧张素Ⅱ干预组主动脉内细胞外基质金属蛋白酶诱导因子mRNA及蛋白表达较对照组明显增加。结论血管紧张素Ⅱ能诱导主动脉粥样硬化斑块内细胞外基质金属蛋白酶诱导因子的表达。     

细胞外基质金属蛋白酶诱导因子和尿激酶型纤溶酶原激活物在载脂蛋白E基因敲除小鼠主动脉粥样硬化斑块中的表达

目的探讨细胞外基质金属蛋白酶诱导因子(EMMPRIN)与尿激酶型纤溶酶原激活物(uPA)在载脂蛋白E基因敲除(ApoE-/-)小鼠主动脉粥样硬化斑块中的表达,并探讨两者的相互关系。方法研究对象采用ApoE-/-小鼠,共喂养18周,分别于6周、10周、14周和18周4个时间点处死小鼠行HE染色切片观察动脉粥样硬化斑块形态;并采用RT-PCR及Western blot检测主动脉粥样硬化斑块内EMMPRIN和uPA的表达。结果成功建立动脉粥样硬化模型;在主动脉粥样硬化斑块中检测到EMMPRIN和uPA表达均增高,与普通饮食组比较有统计学意义(P<0.05)。EMMPRIN和uPA表达随喂养时间延长而增高。结论 EMMPRIN和uPA在ApoE-/-小鼠主动脉粥样硬化斑块中随着斑块病变程度的严重性增加表达增高,两者可能共同参与粥样硬化斑块的发生发展过程。     

基质金属蛋白酶在冠心病中的研究进展

动脉粥样硬化是急性心肌梗死 (AMI)和不稳定型心绞痛 (UAP)等临床综合征的病理基础 ,基质金属蛋白酶 (MMP)通过降解细胞外基质在心血管重塑中起到重要作用。在动脉粥样硬化斑块中可检测到增强的MMP表达 ,MMPs(基质金属蛋白酶家族 )的活动与斑块破裂有关。MMP表达既与斑块的不稳定有关 ,也与再狭窄病变的形成有关。特异性对抗MMPs的治疗药物的发展 ,将有助于预防动脉粥样硬化发展、斑块破裂和再狭窄的形成。     

普罗布考对高脂喂养LDLR-/-小鼠动脉粥样硬化的影响及机制研究

目的探讨普罗布考对高脂喂养LDLR-/-小鼠动脉粥样硬化的影响并初步阐明其作用机制。方法14只8周龄LDLR-/-雄性小鼠,予以高脂喂养4周后随机分为高脂组（继续高脂饮食,n=7）和普罗布考组（高脂加0．5％普罗布考,n=7）,喂养14周后处死,检测血浆中甘油三酯（TG）、总胆固醇（TG）和高密度脂蛋白胆固醇（HDL—C）水平;取主动脉进行油红0染色观察斑块生长情况;制作主动脉根部冰冻切片,分别进行油红0、Masson染色,检测主动脉根部斑块面积和胶原含量;ELISA检测血浆中炎症因子IL-12p70水平。结果普罗布考组小鼠血浆TG、HDL—C显著低于高脂组（P均〈0．01）,TG无显著改变（P〉0．05）;油红O染色结果显示,两组间主动脉斑块占主动脉比例无显著差异（P〉0．05）,但普罗布考组小鼠主动脉根部斑块面积显著高于高脂组（P〈0．01）;Masson染色结果显示,普罗布考组小鼠主动脉根部斑块中胶原比例显著高于高脂组（P〈0．01）;ELISA结果显示,普罗布考组小鼠血浆IL-12p70水平显著低于高脂组（P〈0．05）。结论普罗布考可降低高脂喂养的LDLR-/-小鼠血浆TG、HDL-C和IL-12p70水平,促进主动脉根部斑块形成,但增加主动脉根部斑块中胶原含量。     

基质金属蛋白酶抑制物-2基因转移对家兔动脉粥样硬化斑块的影响

目的探讨局部转染金属蛋白酶抑制物(pcDNA3TIMP2)基因对动脉粥样硬化斑块的影响。方法内皮剥脱加高脂饮食建立兔动脉粥样硬化动物模型,基因球囊局部转染pcDNA3TIMP2,RT PCR和Westernblot分别检测动脉粥样硬化斑块局部外源基因转移效果,Zymography检测动脉粥样硬化斑块局部基质金属蛋白酶(MMPs)活性,病变股动脉组织行HE和苦味酸酸性品红染色,全自动图像分析仪行图像处理,测量血管腔面积、胶原成分含量。结果基因转染组术后2周动脉粥样硬化局部TIMP2基因表达即明显高于空白载体对照组(P<0.01),术后4周达高峰;术后2、4、8周TIMP2蛋白表达也明显高于空白载体对照组(P<0.01),MMP2和MMP9活性低于对照组。局部转染TIMP2基因组动物,动脉粥样硬化斑块纤维帽厚度和病变局部胶原含量均明显高于对照组,但病变血管腔面积与对照组差异则无统计学意义。结论动脉粥样硬化局部转移TIMP2基因可明显抑制病变局部MMP2和MMP9活性,增加动脉粥样硬化斑块纤维帽厚度和病变局部胶原含量,但对动脉粥样硬化所致血管腔狭窄程度无明显影响。     

脑心通调节基质金属蛋白酶及其抑制剂表达的研究

目的观察脑心通胶囊稳定实验性动脉粥样硬化（AS）易损斑块的作用，探讨基质金属蛋白酶9（MMP9）及其抑制剂（TIMP1）对AS斑块发展及稳定性的影响。方法45只兔腹主动脉球囊拉伤后高脂喂养，12周末随机分为脑心通组、辛伐他汀组及对照组。24周末处死分离腹主动脉进行免疫组化和实时定量RT—PCR分析。结果免疫组化显示，MMP9和TIMP1在对照组斑块内阳性细胞数多于脑心通组；实时定量RT—PCR分析结果显示对照组mRNA表达量高于脑心通组及辛伐他汀组，且脑心通组与辛伐他汀组组间比较无统计学意义。结论MMP9和TIMP-1是测定动脉粥样硬化斑块稳定性的重要指标，脑心通胶囊能下调其在斑块内的表达，从而降低斑块的易损性。     

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.     

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.     

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.     

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.