脑出血与细胞凋亡

近年来的研究表明，细胞凋亡是脑出血的继发性损伤机制之一。脑出血后细胞凋亡可能与出血后凝血酶大量释放、红细胞分解产物聚积、兴奋性氨基酸受体激活、多种细胞因子表达和炎性细胞浸润等有关，是一个复杂的病理生理学过程。干预这些病理生理学环节有可能抑制脑出血后细胞凋亡，并为防治出血后的继发性脑损伤找到一些新的途径。     

脑出血与细胞凋亡

近年来的研究表明,细胞凋亡是脑出血的继发性损伤机制之一。脑出血后细胞凋亡可能与出血后凝血酶大量释放、红细胞分解产物聚积、兴奋性氨基酸受体激活、多种细胞因子表达和炎性细胞浸润等有关,是一个复杂的病理生理学过程。干预这些病理生理学环节有可能抑制脑出血后细胞凋亡,并为防治出血后的继发性脑损伤找到一些新的途径。     

脑出血后继发性脑损伤机制研究进展

脑出血是具有高病死率和高致残率的神经科常见疾病。近年研究证实,脑出血发病过程中存在炎症反应、氧化应激、凝血酶神经毒性、小胶质细胞激活、细胞凋亡等继发性脑损伤机制,继发性脑损伤是导致脑出血后神经细胞损伤的重要因素。目前尚缺乏有效的治疗脑出血手段,研究脑出血后继发性脑损伤机制,为脑出血治疗提供一条新途径。     

核因子-κB在脑出血后继发性脑损伤中作用的研究进展

核因子-κB(NF-κB)是一种广泛存在于真核细胞内,能将信息从胞浆传至胞核引起相应基因表达的重要转录因子,在机体免疫和炎症反应、细胞凋亡等有关基因转录过程中具有重要的调控作用。脑出血诱导了NF-κB的激活,活化的NF-κB参与炎性反应、诱导细胞凋亡、介导自由基损伤等机制加重了脑出血后继发性脑损伤。NF-κB将为脑出血后继发性脑损伤的病理生理机制及治疗开辟新途径。     

炎症反应在脑出血后细胞凋亡中的作用

脑出血后血肿周围区可发生继发性损伤。最近的研究表明，血肿周围区出血后神经细胞的死亡，其中炎症反应在脑出血后细胞凋亡中起着十分重要的作用，包括白细胞和小胶质细胞渗出、多种细胞因子的表达以及基质金属蛋白酶和凝血酶的释放。对脑出血后炎症反应的作用进行研究，有望找到新的脑出血治疗的切入点。     

炎症反应在脑出血后细胞凋亡中的作用

脑出血后血肿周围区可发生继发性损伤。最近的研究表明,血肿周围区出血后神经细胞的死亡,其中炎症反应在脑出血后细胞凋亡中起着十分重要的作用,包括白细胞和小胶质细胞渗出、多种细胞因子的表达以及基质金属蛋白酶和凝血酶的释放。对脑出血后炎症反应的作用进行研究,有望找到新的脑出血治疗的切入点。     

脑出血后继发性脑损伤机制

脑出血后继发性脑损伤与脑水肿、炎症反应以及其他损伤因素,如补体系统激活、兴奋性氨基酸毒性、血管活性物质释放和自由基损伤等密切相关.脑出血后继发性脑损伤时的神经元死亡方式主要为坏死和凋亡.     

脑出血家兔模型血肿周围脑组织细胞凋亡与c-fos表达水平的关系

目的 探讨血肿周围脑组织细胞凋亡与c-fos mRNA及c-fos蛋白表达的关系及脑出血后继发性损伤的机制.方法 健康家兔42只,随机分为正常组6只,出血模型组36只,采用多种方法检测血肿周围组织中的凋亡细胞、c-fos mRNA、c-fos蛋白的表达.结果 与对照组相比,实验组出血后0.5h内可见凋亡细胞,逐渐增多,48 h到高峰;c-fos mRNA在脑出血后0.5h达到高峰,依次递减,24 h后就基本消失;c-fos蛋白表达则延后,在脑出血后半小时表达比较明显,2h达高峰,6h仍然较明显,随后递减.结论 脑出血后血肿周围的脑组织中细胞凋亡与c-fos相关,即早基因之一的c-fos可能对其具有调节作用.     

小胶质细胞在脑出血中的作用研究进展

脑出血是一种严重的中枢神经系统出血性损伤,出血后炎性反应在其发病后损害及修复中发挥重要作用。小胶质细胞是神经系统固有免疫细胞,脑出血后小胶质细胞激活,可分泌抗炎因子如白细胞介素10、神经生长因子-1及促炎因子白细胞介素1、肿瘤坏死因子α等,在脑出血继发损伤中起到促炎致损及抑炎修复的双向作用。调节小胶质细胞功能状态,增强其组织保护功能,可以促进脑出血后血肿清除,减弱炎性反应,减轻继发性损伤。作者就脑出血后小胶质细胞的激活与功能作用及相关分子机制进行综述,以期为脑出血治疗提供新思路。     

脑出血后神经细胞死亡机制的研究进展

正脑出血后血管内容物通过理化损伤机制,尤其血液成分所产生的大量细胞毒性因子造成神经细胞不同形式的死亡。研究显示,在人和动物脑出血标本中均发现了血肿周围组织存在坏死、凋亡、自噬、坏死性凋亡等神经细胞的多种死亡方式[1]。近年来,有研究报道铁死亡为小鼠脑出血模型中存在的新的细胞死亡方式[2-3]。由此可见,脑出血后继发性神经细胞死亡机制具有多样的生物学特性。本研究对脑出血后继发性神经细胞死亡方式的特点、调节机制、干预靶点等进行综述。     

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.     

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.     

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.