半夏泻心汤抑制DMH/DSS诱导的结肠炎相关性结肠癌的发生

目的:观察半夏泻心汤对DMH/DSS诱导的结肠炎向结肠癌转变的抑制作用.方法:♂ICR小鼠65只,随机分为正常组、模型组和半夏泻心汤3个剂量(100,200,400 mg/ kg)给药组.采用腹腔注射1,2-二甲肼20 mg/kg及饮用含20 g/L的右旋葡聚糖苷钠复制结肠炎相关的小鼠结肠癌.除模型组20只小鼠,其余30只存活小鼠在出现第二次便血时分别口服给予半夏泻心汤100,200和400 mg/kg进行治疗,1次/d,共11 wk.实验第20周,乙醚麻醉处死小鼠,截取结肠,称重;记录结肠肿瘤数目,取结肠做HE染色:摘取脾脏、胸腺称重.结果:在实验第20周,40%的模型组小鼠出现脱肛,成癌率为85%.半夏泻心汤3个剂量组则未见脱肛小鼠,100 mg/kg组成癌率为20%,200和400 mg/kg成癌率为10%.DMH/DSS诱导的结肠癌小鼠脾脏指数显著升高(6.50±4.08 mg/g vs 4.25±3.39 mg/g,P<0.01),而胸腺指数则明显降低(0.60±0.33 mg/g vs0.71±0.29 mg/g,P<0.05),与对照组相比有显著性差异.半夏泻心汤可明显的对抗结肠癌小鼠胸腺的萎缩(P<0.05),而对脾脏的增大也有明显的治疗作用(P<0.01).病理结果表明,半夏泻心汤成功的将小鼠结肠停留在炎症状态,阻止了结肠炎向结肠癌的转变.结论:半夏泻心汤能够显著地抑制结肠炎向结肠癌的转变,结肠炎的有效治疗是防止结肠癌发生的重要措施.     

选择性环氧合酶-2抑制剂PC407对TNBS诱导的大鼠溃疡性结肠炎的治疗作用

目的:观察新型选择性环氧合酶-2抑制剂PC407对2,4,6-三硝基苯磺酸(2,4,6-trinitrobenzenesulfonic acid,TNBS)诱导的大鼠溃疡性结肠炎的疗效并探讨其机制.方法:应用TNBS/乙醇灌肠复制大鼠溃疡性结肠炎模型,实验设正常对照组、模型对照组、塞来昔布阳性对照组(18 mg/kg)和PC407治疗组(9,18 mg/kg),ig给药,每天1次,共6 d,观察稀便出现情况.实验第7天,麻醉大鼠,分离大鼠结肠、脾脏、胸腺,观察各组实验动物体质量变化及结肠组织病理学改变,选用稀便率、结肠指数、溃疡比、胸腺指数和脾脏指数作为衡量治疗效果的指标,采用免疫组织化学方法检测结肠黏膜环氧合酶-2(COX-2)和肿瘤坏死因子a(tumor necrosis factor-alpha,TNF-a)的变化.结果:与模型组相比,18 mg/kg PC407治疗可明显阻止结肠炎大鼠的体质量下降(258.9 gvs 223.6 g,P＜0.05),降低稀便发生率(30% vs80%.P＜0.01),改善大鼠结肠组织损伤及病理学改变,包括降低结肠指数(5.03±1.26 mg/gvs 7.60±2.07 mg/g.P＜0.01)及溃疡比(24.69%±2.83% vs 36.13%±9.64%,P＜0.01);同时,PC407治疗可对抗结肠炎症引起的胸腺萎缩(1.964-0.48 mg/g vs 1.08±0.32 mg/g,P＜0.01)和脾脏肿大(2.85±0.33 mg/g vs 3.87±0.96mg/g,P＜0.01),显著降低结肠炎大鼠结肠黏膜COX-2和TNF-a的阳性表达率(30.6%±7.0%vs 67.4%±1.2%,19.5%±3.0% vs 52%±4.7%,P＜0.01).9 mg/kg PC407也可以改善以上指数,只是作用没有18 mg/kg明显.结论:PC407对TNBS/醇诱导的大鼠溃疡性结肠炎治疗作用良好,其机制可能通过下调COx-2及TNF-a的表达,从而缓解结肠炎症.     

小鼠日本血吸虫性肝纤维化组织TGF-β1及Smads的表达

目的:探讨小鼠日本血吸虫病纤维化肝组织中转化生长因子(transforming growth factor-β1,TGF-β1)、Smad2/3、Smad4和Smad7的表达和肝纤维化的发病机制.方法:清洁级6-8 wk龄ICR小鼠80只,雌雄各半,随机分为模型组和正常对照组,用血吸虫尾蚴腹部贴附法制成动物模型,正常组未予处理.感染后wk 4、6、8和12末分批处死2组小鼠且称肝脾质量,取部分肝做病理学观察,HE染色和猩红染色,制作组织芯片,免疫组化检测TGF-β1、Smad2/3、Smad4和Smad7在各细的表达状况.结果:与正常组相比,模型组小鼠肝脾质量和肝指数均高(肝,12 wk:2.99±0.28 g vs 1.83±0.13 g;脾,12 wk:0.87±0.15 g vs 0.14±0.02g;肝指数,12 wk:0.09±0.01 vs 0.04±0.00;均P＜0.01),TGF-β1和Smad2/3表达也均高于正常对照组(TGF-β1.12 wk:0.105±0.008 vs 0.024±0.002;Smad2/3.12 wk:0.094±0.009 vs 0.003±0.001,均P＜0.01),以上指数分别与肝纤维化程度呈正相关(r=0.635,0.482,0.646,0.347,0.662;均P<0.01);Smad4表达高于对照组且随着纤维化的发展表达量在逐渐下降(4wk:0.075±0.011 vs 0.023±0.006.6 wk:0.043±0.008 vs 0.010±0.002.8 wk:0.038±0.009 vs 0.003±0.002.12 wk:0.028±0.004 vs 0.013±0.006;均P＜0.01).Smad7仅8 wk表达增强.结论:TGF-β1和Smad2/3表达增强在肝纤维化的发生中起重要作用,Smad4可能主要在纤维化的早中期发挥效应.     

黄芪总苷对小鼠日本血吸虫病肝纤维化的影响

目的:研究黄芪总苷(AST)对小鼠日本血吸虫病肝纤维化和虫卵肉芽肿的影响.方法:以日本血吸虫尾蚴感染ICR小鼠制作肝纤维化动物模型,5 wk末随机分为:AST高剂量组20 mg/(kg·d)、AST低剂量组10 mg/(kg·d)、阳性药护肝片组540 mg/(kg·d)和模型对照组,各组均于感染40 d后,吡喹酮杀虫2 d 500mg/(kg·d).同时设置正常对照组30只.感染后6、10和14 wk每组随机处死10只,观察肝脏指数,应用HE和天狼猩红染色观察小鼠虫卵结节大小及纤维化程度;构建组织芯片,应用免疫组织化学方法检测虫卵结节中Ⅰ、Ⅲ型胶原蛋白的表达.结果:感染后10、14 wk, AST高、低剂量组与模型组相比较,肝组织中血吸虫虫卵结节显著缩小,纤维化程度明显减轻,Ⅰ、Ⅲ型胶原蛋白含量(MOD)明显减低(10 wk: 0.093±0.002、0.084±0.003 vs 0.134±0.004,P＜0.01;0.074±0.002、0.104±0.005 vs 0.146±0.008,P＜0.05;14 wk: 0.099±0.004、0.095±0.004 vs 0.141±0.007,P＜0.01;0.070±0.003、0.077±0.003 vs 0.101±0.004,P＜0.05).感染10 wk,AST高、低剂量组Ⅲ型胶原蛋白含量有统计学差异(P＜0.01).结论:AST通过抑制虫卵结节、减少Ⅰ、Ⅲ型胶原的合成发挥抗小鼠日本血吸虫病肝纤维化的作用.     

硝酸酯在小鼠急性实验性结肠炎中的治疗作用

目的 观察硝酸酯对小鼠急性实验性结肠炎的疗效.方法 将40只BALB/c小鼠均分为模型组和治疗组,模型组予4％葡聚糖硫酸钠(DSS)溶液,治疗组予4％DSS溶液和1.5 g/L硝酸酯溶液,均连续饮用7d.对小鼠疾病活动指数(DAI)进行评分.取小鼠结肠组织进行苏木精-伊红染色和髓过氧化物酶(MPO)免疫组织化学染色并进行观察.分别用MPO和一氧化氮检测试剂盒检测结肠组织MPO和一氧化氮活性.统计学处理采用t检验.结果 第6和第7天治疗组和模型组的DAI差异有统计学意义(t=5.12和6.72,P=0.012和0.008).第7天时模型组组织学评分(2.5±0.5)高于治疗组(1.9±0.4),差异有统计学意义(t=3.82,P＜0.01).与模型组相比,治疗组小鼠结肠组织病理损伤明显减轻,中性粒细胞浸润减少.第7天时模型组MPO活性、NO2-浓度、NO3-浓度分别为(2.8±0.6) U/g、(10.4±4.3) mmol/g、(100.3±50.1)mmol/g,治疗组则分别为(1.5±0.3)U/g、(17.5±7.0)mmol/g、(190.7±85.3) mmol/g,差异均有统计学意义(t=11.23、3.81、4.50,P均＜0.01).结论 硝酸酯可减轻DSS诱导的小鼠急性实验性结肠炎.     

葡聚糖硫酸钠自由饮用与定量灌胃诱导小鼠急性结肠炎模型的比较研究

背景：自由饮用葡聚糖硫酸钠（DSS）诱导的鼠类急性结肠炎模型均一性欠佳,动物死亡率较高。目的：评估2%DSS自由饮用或定量灌胃诱导的小鼠急性结肠炎模型模拟人类溃疡性结肠炎（UC）的效果和均一性。方法：予ICR小鼠2%DSS自由饮用或定量灌胃建立急性结肠炎模型,检测并比较正常对照组和两组模型小鼠的症状出现时间和频率、疾病活动指数（DAI）、DSS消耗量、死亡率、结肠长度、结肠损伤大体评分（MACD）、结肠组织病理学表现以及外周血白细胞计数和分类。结果：两组模型小鼠均出现类似人类UC的症状和组织病理学改变,结肠显著短缩,DAI、MACD以及外周血白细胞计数和中性粒细胞百分比显著高于正常对照组。与DSS自由饮用组相比,DSS定量灌胃组小鼠症状出现时间更为一致,症状出现率显著增高,动物死亡率和DSS消耗量显著减低。结论：2%DSS定量灌胃诱导的小鼠急性结肠炎模型能较稳定地模拟人类UC,均一性高,动物死亡率低。     

地龙提取液对结肠炎相关性结肠癌Wnt/β-catenin信号通路的影响

[目的]探讨地龙提取液对结肠炎相关性结肠癌疗效及其作用机制。[方法]小鼠随机分为空白组、模型组、地龙提取液(低、中、高剂量组)和美沙拉嗪组,并采用AOM/DSS法复制结肠炎相关性结肠癌癌前病变动物模型。治疗结束后分别测量各组小鼠胸腺、脾脏及结肠的质量,并光镜下观察结肠组织病理学改变,免疫印迹法检测结肠组织中Wnt/β-catenin信号通路中相关蛋白的表达。[结果]地龙提取液能够显著增加小鼠胸腺的质量和结肠长度(P0.05),减少脾脏和结肠质量(P0.05),降低AOM/DSS诱导小鼠的成瘤率(P0.05),改善CAC小鼠结肠组织的病理学形态;此外,地龙提取液能够显著减少CAC小鼠结肠组织中Wnt3a、phospho-GSK-3β、β-catenin、c-Myc、cyclin-D1蛋白表达(P0.05),增加APC、Axin1、GSK-3β、phospho-β-catenin、Bcl-2蛋白的表达(P0.05)。[结论]地龙提取液能够预防结肠炎后结肠癌的发生与发展,其作用机制是通过抑制Wnt/β-catenin信号通路的活化实现的。     

5-氨基水杨酸在结肠炎癌变模型小鼠中的初步研究

目的 应用5-氨基水杨酸(5-ASA) 干预偶氮氧甲烷(AOM)联合葡聚糖硫酸钠(DSS)诱导小鼠结肠炎癌变的模型,观察结肠过氧化物酶体增殖物激活受体γ(PPAR-γ)、β-catenin的表达水平.方法 36只BALB/c小鼠均分为对照组、模型组和干预组.模型组和干预组均于实验前1d予AOM 10 mg/kg腹腔注射,继以自由饮用4％DSS 1周,再普通饮水2周,饮用DSS及普通饮水共重复3个循环.干预组于实验前3d予5-ASA 150 mg/kg饲喂至实验结束.对照组于实验前1d予0.9％ NaCl溶液腹腔注射,普通饮水9周.监测小鼠疾病症状,评价实验1周末及9周末结肠组织学病理变化,检测9周末结肠PPAR-γ、β-catenin蛋白及结肠PPAR-γ mRNA表达水平.统计学处理采用t检验.结果 干预组饮用DSS 1周后结肠炎疾病活动指数(DAD为1.81+0.59,9周末平均肿瘤数为4.11±1.05,均较模型组(DAI为2.47±0.53,肿瘤数为9.71±2.29)明显降低(t=2.88和6.55,P均＜0.01).干预组结肠PPAR-γ蛋白(2.11±1.36)及mRNA(1.45±0.10)平均表达水平均较模型组(分别为0.43±0.53,0.57±0.08)明显增加(t=3.07和18.99,P均＜0.01).各组间β-catenin表达差异无统计学意义(P＞0.05).结论 5-ASA有效减轻AOM和DSS诱导的小鼠结肠炎癌变模型的炎性反应及肿瘤负荷,同时促进PPAR-γ在结肠中的表达,而对结肠中β-catenin的表达无明显影响.     

干细胞因子对糖尿病小鼠结肠Cajal间质细胞的干预效应

目的:探讨外源性干细胞因子(stem cell factor,SCF)能善糖尿病(diabetes mellitus,DM)小鼠结肠Cajal间质细胞(interstitial cells of Cajal,ICC)的异常病变.方法:DMd、鼠一次性ip链脲佐菌素(STZ,150mg/kg)造模,将♂ C57/BL6小鼠分为正常对照组(control组)、糖尿病组(DM组)、糖尿病 外源性SCF组(DM SCF组):DM SCF组ip SCF0.2 μg/(kg穌),control组和DM组每天ip等量的磷酸盐缓冲液(pH=7.4),干预6 wk后处死所有小鼠,以Western blot检测远端结肠组织中SCF的表达情况,以免疫组化、透射电镜和Western blot观察远端结肠ICC的变化.结果:DM小鼠远端结肠组织中SCF水平明显降低(178.97±13.51 vs 200.25±16.48,P<0.05),且伴结肠组织中ICC数量减少(72±10 vs 102±12.P＜0.05)、超微结构严重破坏.DM鼠给予外源性SCF干预后,结肠组织中SCF表达(210.14±11.8)上调(P＜0.05),且ICC的数量(87±10,P＜0.05)和超微结构显著改善.结论:外源性SCF对糖尿病相关的结肠ICC异常病变有一定改善或逆转作用.     

代谢综合征小鼠肝脏过氧化物增殖体受体γ共同作用因子-1的表达

目的探讨代谢综合征小鼠肝脏过氧化物增殖体受体γ共同作用因子-1(PGC-1)表达.方法进正常食C57BL/6J小鼠10只、进高脂高糖食8 wk小鼠5只及16 wk小鼠10只.测定血脂、血清胰岛素(INS)及空腹血糖、肝功、肝脏重质量、腹部瘦肉及瘦肉含量,肝脏脂质含量及PGC-1蛋白表达采用Western blot免疫印迹,并做肝脏病理.结果进高脂高糖食16 wk的小鼠腹部脂肪量、血清甘油三酯(TC)和空腹血糖(FBG)均明显高于正常小鼠(腹部脂肪量3.63±0.62vs 2.99±0.31, P＜0.01;TC2.31±0.16 mmol/Lvs 2.04±0.15 mmol/L,P＜0.01;FBG6.90±1.84 mmol/L vs 5.11±1.86 mmol/L,P＜0.05).高脂高糖食的动物血清TP、ALB及A/G低于正常动物,其中进食16 wk的动物ALB及A/G有显著差异(ALB18.12±2.63 g/L vs 21.64±3.38 g/L,P＜0.05;A/G0.89±0.15 vs 1.06±0.18,P＜0.05).血清ALT,ALP及AST高于正常动物,其中进食16 wk的动物的ALP有显著差异(103.80±8.72 U/L vs 64.60±10.67 U/L,P＜0.05).高脂高糖食小鼠肝脏有明显脂肪变性,16 wk重于8 wk的小鼠.16 wk进高脂高糖食的小鼠肝脏的TC和TG含量显著高于正常动物,达到正常的2倍以上(TC0.0582±0.0251 mmol/g干重vs 0.0275±0.0114 mmol/g干重,P＜0.01;TG0.1566±0.0166 mmol/g干重vs 0.0631±0.0232 mmo1/g干重,P＜0.01).高脂高糖食小鼠肝脏PGC-1表达高于正常动物,16 wk强于8 wk的小鼠.结论高脂高糖食C57BL/6J小鼠可作为代谢综合征动物模型,其存在脂肪肝,肝脏的PGC-1蛋白表达量高于正常食小鼠,可能其参与脂肪肝的形成.     

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.