扩展高胰岛素-正葡萄糖钳夹技术的建立

目的建立扩展高胰岛素-正葡萄糖钳夹技术.方法应用扩展葡萄糖钳夹技术(即联合葡萄糖钳夹、3-3H标记葡萄糖示踪技术及间接测热技术)对9例正常体重、正常糖耐量者进行方法学研究.结果(1)在优势浓度胰岛素、血浆葡萄糖稳定在正常水平状态下肝糖产生完全被抑制,未见到升糖激素(皮质醇、生长激素、胰高血糖素)显著兴奋及内源性胰岛素释放.(2)扩展高胰岛素-正葡萄糖钳夹稳态期,胰岛素介导的机体葡萄糖利用率(葡萄糖消失率)较基础状态显著增加[(5.86±0.65)mg*kg-1*min-1比(2.45±0.15)mg*kg-1*min-1,P＜0.01],并以糖原合成为主;脂肪氧化被显著抑制,游离脂肪酸浓度显著下降.结论扩展高胰岛素-正葡萄糖钳夹技术已成功建立;在外源性胰岛素-葡萄糖代谢的稳定状态下,机体对葡萄糖利用显著增加,脂肪分解显著减少.     

肾上腺髓质素对正常Wistar大鼠胰岛素敏感性的影响

用高胰岛素正常血糖钳夹试验,联合放射性同位素稀释示踪技术观察肾上腺髓质素(AM)对正常Wistar大鼠胰岛素敏感性的影响。输入生理盐水及0.05、0.2、1μg·kg-1·min-1等不同剂量的AM,测定葡萄糖利用率(GDR)、肝脏葡萄糖输出率(HGO)。AM可使正常Wistar大鼠胰岛素刺激下的GDR值下降,并有剂量依赖趋势,尤以1μg·kg-1·min-1最明显(下降51%),可能还有增加HGO的作用,提示较高浓度的AM可导致以外周为主的胰岛素抵抗的发生。     

短期胰岛素泵强化治疗对新诊断2型糖尿病患者胰岛素分泌和敏感性的影响

目的 探讨短期胰岛素泵强化治疗对新诊断2型糖尿病患者胰岛素敏感性和胰岛素分泌功能的影响.方法 选取2006年6月至2007年2月在本院就诊的新诊断2型糖尿病患者10例进行为期2周的胰岛素泵强化治疗,在治疗前和停泵24 h后分别进行两次静脉葡萄糖耐量试验(IVGTT)和高胰岛素-正葡萄糖钳夹试验.结果 (1)在治疗前所有糖尿病患者均缺乏急性胰岛素分泌(AIR),经2周强化治疗使血糖正常后,所有患者AIR均有了不同程度地恢复[(7.63±4.73 vs 0.83±1.96)mU/L,P＜0.01)].AIR恢复较好的患者略为年轻和肥胖.(2)糖耐量正常志愿者平均葡萄糖输注率(GIR)为(8.26±2.48)mg·kg-1·min-1,而初发2型糖尿病患者在胰岛素泵强化治疗前GIR为(2.30±0.81)mg·kg-1·min-1(与正常者比,P＜0.01),胰岛素泵强化治疗后GIR升高到(5.33±1.43)mg·kg-1·min-1(P＜0.01).GIR升高显著的患者腰围和体重指数低、治疗前的平均血糖高.结论 短期胰岛素泵强化治疗使血糖"正常化",同时可改善胰岛细胞功能,提高胰岛素敏感性.     

早期营养不良对大鼠成年后胰岛素抵抗和糖耐量异常的影响

目的　探讨早期营养不良大鼠成年后胰岛素敏感性和糖代谢变化。　方法　建立早期营养不良大鼠动物模型 ;给予孕期 14d大鼠半量饲料饲养至哺乳期结束 ,造成其子鼠早期营养不良 ;对成年子鼠行腹腔内注射葡萄糖耐量试验和高胰岛素 正常血糖钳夹术。　结果　早期营养不良组(试验组 )子鼠与对照组子鼠比较 ,糖耐量试验各时间点血糖升高 (P <0 0 1) ;试验组子鼠稳态葡萄糖输注速率值 (2 8± 5 )mg·kg-1·min-1较对照组子鼠 (4 0± 7)mg·kg-1·min-1显著降低 (P =0 0 0 2 )。　结论　早期营养不良致大鼠成年后糖耐量受损 (IGT)和胰岛素抵抗 (IR)。     

一氧化氮改善糖尿病大鼠高糖毒性导致的胰岛素敏感性下降

目的　观察NO能否改善链脲佐菌素 (STZ)糖尿病大鼠高糖毒性导致的胰岛素敏感性下降。方法　对清醒状态下的STZ糖尿病大鼠(24只)和正常大鼠 (24只 )在实施正血糖高胰岛素钳夹实验同时,分别给予硝普钠、NG 甲基 L 精氨酸(LNMMA)及腺苷,观察葡萄糖代谢率 (MCR,作为胰岛素作用的指标)的变化。结果　糖尿病大鼠生理盐水组的MCR〔(7. 2±0. 8)ml·kg-1·min-1〕明显低于正常对照大鼠〔(18. 0±1. 8 )ml·kg-1·min-1,P<0. 01〕,给予LNMMA的糖尿病大鼠的MCR〔( 5. 0±0. 2 )ml·kg-1·min-1〕有进一步下降趋势,但是给予硝普钠的糖尿病大鼠的MCR〔(15. 3±1. 5)ml·kg-1·min-1,P<0. 01〕明显高于糖尿病大鼠生理盐水组,达到了正常大鼠MCR的 85%,而腺苷没有明显改变糖尿病大鼠的MCR〔(7. 1±0. 7)ml·kg-1·min-1〕。结论　NO可以改善STZ糖尿病大鼠高糖毒性导致的胰岛素作用下降。     

短期胰岛素强化治疗对新诊断2型糖尿病患者不同时相胰岛素分泌的影响

目的应用高葡萄糖钳夹技术评估短期胰岛素强化治疗对新诊断的2型糖尿病(T2DM)患者胰岛素分泌时相的影响。方法对12例正常人及6例新诊断糖尿病患者行高葡萄糖钳夹试验评价胰岛β细胞功能。6例糖尿病患者进行2周胰岛素强化治疗后重复高葡萄糖钳夹试验。结果正常组第一时相胰岛素分泌(1PH)257±36mU/L,第二时相胰岛素分泌(2PH)63±5mU/L,最大胰岛素分泌80±6mU/L。糖尿病组治疗前胰岛素分泌分别为95±19mU/L、34±9mU/L、39±12mU/L显著低于正常组(P均<0·01)。糖尿病组治疗后与治疗前相比,1PH显著改善(135±27vs95±19mU/L,P=0·01),2PH及最大胰岛素分泌量轻度改善,但差异无统计学意义(40±9mU/Lvs34±9mU/L,P=0·09;46±11mU/Lvs39±12mU/L,P=0·08)。结论对新诊断的T2DM患者2周胰岛素强化治疗能够明显改善胰岛素1PH分泌,并对2PH分泌及最大分泌可能也有改善作用。     

静脉输注胰淀素对大鼠胰岛激素分泌及血糖的影响

目的 观察外源性胰淀素对高脂饲养的SD大鼠胰岛素分泌第一时相胰高血糖素和胰岛素分泌的影响.方法 32只8周龄雄性SD大鼠随机分为常规饲养组(CC组)、高脂饲养组(CF组)、高脂饲养低剂量胰淀素组(AmyL组)、高脂饲养高剂量胰淀素组(AmyH组).饲养28周后进行静脉葡萄糖耐量试验(IVGTT),分别于静脉注射葡萄糖后0、3、5、10 min留取动脉血检测胰岛素及胰高血糖素水平,并同时测定血糖.AmyL组和AmyH组大鼠IVGTT前50 min开始以410 pmol·kg-1·min-1及610 pmol·kg-1·min-1的速度泵入胰淀素溶液.结果 AmyH组胰高血糖素水平显著低于CF组(P＜0.01);AmyL组及AmyH组大鼠胰岛素水平均显著低于CF组(P＜0.05, P＜0.01);AmyL组及AmyH组血糖均高于CF组(P＜0.05).结论 胰淀素在一定浓度范围可抑制胰高血糖素的异常分泌,但同时降低胰岛素分泌,且此作用强于抑制胰高血糖素的作用,造成血糖升高,提示胰淀素对血糖的影响可能与其对胰岛素及胰高血糖素分泌抑制之间的平衡有关.     

高脂饮食对老年大鼠肝脏脂肪酸代谢及胰岛素敏感性的影响

目的 探讨增龄和高脂饮食对大鼠肝脏脂肪酸代谢及胰岛素敏感性的影响,了解老年大鼠胰岛素抵抗(IR)的发病机制. 方法 将22～24月龄雄性Wistar大鼠随机分为老年对照组和高脂组;4～5月龄大鼠作为青年对照组.老年对照组和青年对照组给予基础饲料,高脂组给予高脂饲料,喂养8周.用高胰岛素-正葡萄糖钳夹实验评价各组大鼠胰岛素敏感性;肝脏三酰甘油经氯仿/甲醇抽提后用全自动生化分析仪测定. 结果 (1)老年对照组空腹血糖、胰岛素和游离脂肪酸均高于青年对照组,高脂组进一步升高,且血清三酰甘油和总胆同醇水平增高;(2)葡萄糖输注率老年对照组[(23.80±2.79)mU·kg-1·min-1]较青年对照组[(30.08±3.89)mU·kg-1·min-1]低,高脂组((18.83±2.18)mU·kg-1·min-1]最低,差异有统计学意义(P<0.01);高脂组8周末较4周末低;(3)肝脏三酰甘油老年对照组较青年对照组升高,分别为(16.6±4.8)μmol/g和(9.6±2.2)μmol/g,高脂组(24.7±6.6)μmol/g较老年对照组进一步升高(P<0.01);在老年组中,肝脏三酰甘油与葡萄糖输注率呈负相关.与空腹血糖呈正相关. 结论 与青年对照组比较,老年对照组更易出现脂肪酸代谢异常及IR;高脂饮食导致老年大鼠肝脏脂质积聚更加严重,进一步加重IR;肝脏脂质堆积可能参与了与增龄和高脂饮食相关IR的发生.     

高葡萄糖钳夹技术的建立

目的　在国内建立检测胰岛素 (Ins)分泌功能的精确方法 :高葡萄糖钳制技术。　方法　对 2 5名居住上海地区的正常中国人 (男 16名 ,女 9名 )进行高葡萄糖钳夹实验。空腹平卧后两侧上肢静脉埋管。一侧持续输注 2 0 %葡萄糖溶液 ,通过负反馈调节机制使血糖始终维持在较基础血糖升高 7.9mmol/L的水平。另一侧静脉定时取血测定Ins水平 ,以获得双相Ins分泌值 ,评价胰岛 β细胞功能。　结果　 (1)受试者血浆葡萄糖浓度在钳夹开始后的指定时间内 (14min)能达到实验所要求的高糖平台 [(12 .86± 0 .11)mmol/L] ,并能维持此水平至实验结束 ;(2 )在维持高糖平台期间 ,每 5min检测的血糖变异系数为 4.2 % ;(3 )可观察到持续高糖水平下双相Ins的分泌形态 ,第一时相Ins分泌为 (2 47.8± 2 3 .5)mU/L ,第二时相为 (72 .8± 6.1)mU/L。 (4)高糖钳夹可同时获得个体的Ins敏感性 (ISI) 19.9± 2 .4,但较正糖钳夹值为高。　结论　 (1)成功建立了高葡萄糖钳夹技术 ,评价了正常个体的双相Ins分泌及最大Ins分泌。 (2 )高葡萄糖钳夹能同时了解机体的胰岛素抵抗 (IR)情况 ,反映不同人群ISI的差异     

Prader—Willi综合征患者一例胰岛素敏感性分析及文献复习

目的评价1例Prader-Willi综合征患者的胰岛素敏感性。方法1例18岁男性患者因体重进行性增加15年就诊，临床确诊为Prader—Willi综合征。对患者进行系统的内分泌检查并行高胰岛素正葡萄糖钳夹试验，评价患者的胰岛素敏感性。结果患者身高156em，体重115kg，体质指数（BMI）47．3kg／m2；糖化血红蛋白6．8％，2次口服葡萄糖耐量试验（OGTr）均达到糖尿病的诊断标准，同步胰岛B细胞功能评价提示晚时相胰岛素分泌高峰延迟。胰岛素：0min43．7mU／L，1h247．6mU／L，2h230．9mU／L。甲状腺功能、肾上腺皮质功能均正常。钳夹试验时基础血浆葡萄糖为4．5mmol／L，钳夹开始20-120min内葡萄糖输注率（GIR）为6．6mg／（kg·min），稳态期GIR为6．2mg／（kg·min）。结论Prader—Willi综合征患者存在胰岛素抵抗。     

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.