经门静脉骨髓基质细胞移植治疗肝纤维化

目的: 探讨移植骨髓基质细胞(BMSCs)减轻小鼠肝纤维化的作用.方法: BALB/c小鼠BMscs分离培养及经门静脉移植到BALB/c小鼠肝脏,二乙基亚硝胺诱导肝纤维化.60只小鼠随机分为对照组.模型组及治疗组.3 mo后测定ALT、AST、透明质酸酶(HA)和层黏连蛋白(LN)浓度,及肝脏羟基脯氨酸(Hyp)含量.免疫组化检测肝脏a.平滑肌肌动蛋白(α-SMA)表达,及荧光原位杂交鉴定移植的BMSCs向肝细胞的分化.结果: BMsCs在添加肝细胞生长因子(HGF)的培养基中体外培养能分化为肝细胞样细胞.与模型组相比.移植BMscs能显著降低血清ALT、AST、HA和LN的水平以及肝脏Hyp含量和α-SMA的表达(208±44 U/L 341±66 U/L,372±84 U/L vs 506±81 U/L,289±74μg/L vs 362±83 μg/L,178±48 μg/L vs 232±63 ug/L,900±141 mg/g liver vs1255±205mg/g liver,,均p<0.01).荧光原位杂交显示DEN诱导的损伤肝脏中有骨髓来源的肝细胞,3 mo后10%的肝细胞来源于BMSCs.结论: 在肝纤维化模型中,经门静脉移植的BMscs能分化为肝细胞,有效地恢复肝功能和减轻肝纤维化.     

维生素C和维生素E对小鼠化学性肝损伤的预防性保护作用

目的:探讨维生素C(VC)和维生素E(VE)对CCl_4引起化学性肝损伤的预防性保护作用.方法:昆明种小鼠60只随机分5组,设正常对照组、病理模型组、VC保护组、VE保护组、VC VE保护组,饲养10 d,除正常对照组外,其余各组ip 1.5 mL/L CCl_4致小鼠化学性肝损伤,测定小鼠血清中ALT,AST及肝细胞中MDA,GSH,SOD,HE染色光镜下观察肝细胞形态变化.结果:VC和VE保护组能显著降低血清中ALT和AST(2277.12±1187.90,2163.76±1412.11 nkat/L vs 4527.07±1019.37 nkat/L,P<0.01)以及肝细胞中脂质过氧化物MDA的含量(4.37±0.49,3.26±0.71μmol/g vs 9.25±2.74μmol/g,P<0.01).镜下观查肝损伤明显减轻,体外抗氧化实验能显著性的抑制脂质过化物MDA生成,联合应用有协同效应.结论:VC和VE对化学性肝损伤有预防性保护作用.     

粒细胞集落刺激因子防治小鼠CCl4所致肝损伤的作用

目的:观察重组人粒细胞集落刺激因子(rhG-CSF)对CCl4所致小鼠肝损伤的保护和治疗作用以及探讨rhG-CSF动员的外周血干细胞在受损肝组织内定植的能力.方法:清洁级BALB/c小鼠,ip 400 mL/LCCl4,2 mL/kg,每周2次,诱导肝损伤,sc rhG-CSF200 μg/kg进行预防和治疗.观察各实验组小鼠的生存率、肝组织病理变化、肝功能等指标.分别用免疫组化及流式细胞术观察肝组织中Thy-1和CD34阳性细胞变化,用Y染色体原位杂交法观察rhG-CSF动员的♂小鼠外周血干细胞在肝受损伤的♀小鼠肝脏内的定居能力.结果:rhG-CSF预防组小鼠的生存率、肝组织病理改变、肝功能的酶学指标均好于模型组(P＜0.05).治疗后30 d,rhG-CSF治疗组小鼠血清中肝功能酶学指标ALT和AST与对照组相比分别有显著性意义(1033.5±350.1 nkat/L vs 1983.7±616.8 nkat/L,P＜0.01;1817.0±483.4 nkat/L vs 3017.3±811.2 nkat/L,P＜0.05).治疗后8 d、15 d rhG-CSF组肝脏组织中Thy-1 和CD34 细胞明显多于对照组(P＜0.05).接受♂小鼠外周血干细胞移植的♀小鼠肝组织可见Y染色体阳性的细胞,主要位于汇管区与中央静脉周围,少数位于脾脏.结论:rhG-CSF预防和治疗均能促进CCl4所致的小鼠肝损伤修复,提高生存率.     

骨髓间充质干细胞对大鼠急性肝损伤修复的影响

目的: 观察骨髓间充质干细胞(BMSCs)移植通过抑制RhoA-ROCK信号转导通路对大鼠急性肝损伤修复过程的影响.方法: 贴壁筛选法培养、纯化♂ S D大鼠BMSCs.将健康♀SD大鼠随机分为3组: 正常对照组(N组,n = 10)、CCl4组(C组,n = 10)及CCl4+BMSCs组(T组,n = 10).N组不予任何处理;T组和C组腹腔注射0.1 mL/100 g 600 mL/LCCl4花生油溶液制造急性肝损伤模型后24 h,分别经鼠尾静脉移植的间充质干细胞和等量PBS.各组于不同时间点留取标本,采用HE染色和血清肝功能酶学指标观察受损肝脏恢复过程;RT-PCR方法检测RhoA mRNA的表达;Western blot检测RhoA蛋白的表达.结果: 与C组相比,T组移植BMSCs后能显著改善CCl4急性损伤大鼠肝功能(1 d,ALT: 89.70±3.09 U/L vs 147.59±6.83 U/L,AST: 263.67±17.05 U/L vs 472.68±19.04 U/L,P＜0.01或0.05;7 d,ALT: 42.38±14.31 U/L vs 92.75±6.70U/L,AST 173.85±16.80 U/L vs 260.41±25.35U/L,均P＜0.05),并迅速修复肝脏结构.N组大鼠肝脏RhoA mRNA和蛋白表达量极低,C组经CCl4损伤后RhoA mRNA和蛋白表达量迅速增加(1.39±0.046 vs 0.57±0.010,1.23±0.020vs 0.35±0.036,均P＜0.01),此后表达量缓慢降低.T组经BMSCs移植后,与C组比较,RhoAmRNA和蛋白表达水平迅速下降.结论: Rho-ROCK信号转导通路参与CCl4导致的急性肝损伤发生、发展和修复全过程.BMSCs可能通过抑制RhoA-ROCK信号转导通路加速受损肝脏修复.     

大鼠骨髓间充质干细胞向类肝细胞体外诱导分化

目的:观察不同条件下骨髓间充质干细胞(MSCs)体外诱导分化为类肝细胞的差异.方法:Wistar大鼠24只随机均分为3组,分别为正常对照组、肝纤维化模型组、自拟中药干预组.采用CCl4乳剂皮下注射建立肝纤维化模型.造模成功后中药干预组采用丹金舒肝胶囊药液灌胃治疗.治疗结束后剖杀大鼠,留取大鼠肝脏标本,HE染色观察各组病理改变.采用密度梯度离心法和贴壁法分离各组大鼠的MSCs,经培养传代获得纯化的MSCs.各组纯化的MSCs采用HGF、FGF-4进行诱导培养.留取15、21、27 d细胞培养液进行白蛋白(Alb)、甲胎蛋白(AFP)检测;于27 d收集细胞爬片,进行糖原染色和CK-18免疫细胞化学染色.结果:3组15、21和27 d各MSCs诱导组AFP水平均高于MSCs非诱导组(P<0.01),其中21 d AFP水平最高(肝纤维化模型组:48.94±0.08 vs 9.90±0.09;中药干预组:49.86±0.29vs 8.69±0.62;正常对照组:38.65±0.33 vs9.04±0.11,均P<0.01);3组15 d各MSCs诱导组与MSCs非诱导组白蛋白水平无统计学意义:21 d、27 d各MSCs诱导组白蛋白水平均高于MSCs非诱导组(1.11±0.08 vs 0.32±0.00,1.25±0.04 vs 0.32±0.00,1.06±0.03 vs 0.33±0.00;1.52±0.02 vs 0.33±0.00,1.79±0.01vs 0.31±0.03,1.63±0.04 vs 0.32±0.01,均P<0.01),27 d最高.27 d各MSCs诱导组糖原染色阳性,免疫细胞化学染色CK-18均阳性,而MSCs非诱导组糖原染色、CK-18均阴性.从AFP、Alb水平综合比较,3组诱导效果发现自拟中药干预组优于其他2组.结论:HGF、FGF-4可在体外诱导实验性大鼠的MsCs分化为具有肝细胞样细胞表型和功能的类肝细胞:自体MSCs可以作为治疗临床重症肝病的一种细胞来源,而临床联合中药复方治疗可能会使MSCs体外诱导的效果更为理想.     

清肝活血方对乙醇性肝纤维化大鼠肝星形细胞和肝细胞凋亡的影响

目的:观察酒精性肝纤维化大鼠Hsc和肝细胞的凋亡及中药清肝活血方对细胞凋亡的影响.方法:以乙醇为主制备酒精性肝纤维化大鼠模型,将造模大鼠分为清肝活血方低(4.75g/kg)、中(14.25g/kg)和高剂量组(28.5g/kg),每日进行ig药物干预2wk,并设空白对照组、模型对照组及易善复对照组.比色法检测血清ALT,AST,γ-GT;HE和Masson染色观察肝组织炎症和纤维化程度.TUNEL检测肝细胞凋亡,TUNEL-α-SMA双标记检测HSC凋亡.结果:清肝活血方用药组及易善复组能降低大鼠血清ALT(1213±245,1432±253nkat/Lvs2140±428nkat/L,P均<0.05),AST(1671±400,2123±413vs4454±850nkat/L,P均<0.05),γ-GT水平(4539±1847,5509±2430vs8271±3304nkat/L,P均<0.05),减轻纤维化程度(5.5±2.50,6.30±3.16vs9.00±2.27,P<0.05);诱导活化的HSC凋亡(5.25%±2.48%,3.63%±2.04%vs2.30%±1.24%,P<0.05),减少肝细胞凋亡(0.43%±0.11%,0.60%±0.16%vs1.77%±0.49%,P<0.05).结论:清肝活血方能有效减轻大鼠肝纤维化程度,并减少乙醇引起的肝细胞凋亡,诱导活化的HSC凋亡.     

骨髓基质细胞在小鼠肝脏内分化及癌变的潜能

目的:探讨骨髓基质细胞(BMSCs)在诱癌小鼠模型中向肝细胞分化及癌变的可能性.方法:♂BALB/c小鼠BMSCs分离培养及经门静脉移植到♀BALB/c小鼠肝脏.二乙基亚硝胺诱导肝癌.6mo后处死小鼠,取肝脏标本.用免疫组织化学检测胎盘型谷胱苷肽转移酶、甲胎蛋白和角蛋白19的表达及用荧光原位杂交(fluorescence in situ hybridisation,FISH)检测Y染色体阳性细胞.结果:BMSCs在添加肝细胞生长因子的培养基中体外培养能分化为肝细胞样细胞.诱癌6mo后26%的小鼠存活并成功诱导肝细胞性肝癌.免疫组织化学显示肝癌细胞表达胎盘型谷胱苷肽转移酶和甲胎蛋白,而不表达角蛋白19.FISH结果显示骨髓基质细胞移植及诱癌6mo后小鼠肝脏内有Y染色体阳性的肝细胞.而无二乙基亚硝胺诱癌的小鼠.BMSCs移植6mo后肝脏内未发现Y染色体阳性的肝细胞.另外,FIsH检测未发现Y染色体阳性的肝癌细胞.结论:在肝癌的小鼠诱癌模型中,移植的BMSCs能分化为肝细胞,但癌变的可能性小.     

非酒精性脂肪肝大鼠肝脏硬脂酰CoA去饱和酶-1表达与ATP浓度之间的关系

目的:研究非酒精性脂肪肝大鼠肝脏SCD-1表达及ATP含量之间的关系.方法:SD大鼠30只分成正常组、高脂组,在实验的第8,16和24周分批处死,观察肝脏组织学改变,荧光素酶-荧光素法测定肝脏ATP含量,RT-PCR实时荧光分析大鼠肝SCD-1mRNA与β-actinmRNA的比值.结果:肝组织HE染色显示高脂组大鼠肝脏内有弥漫性肝细胞脂肪变性,8wk达到脂肪肝诊断标准.8wk表现为单纯性脂肪肝,16-24wk进展为脂肪性肝炎.电镜下发现实验组与对照组相比,肝细胞线粒体肿胀、增大,部分内膜嵴粒脱落,16wk发现线粒体内有类圆形结晶样物质沉积.实验组肝SCD-1mRNA表达下降,8,16和24wk的测定值分别为0.39±0.18vs0.83±0.28(P<0.05)、0.44±0.17vs0.81±0.30(P<0.05)和0.47±0.23vs0.88±0.22(P<0.01);每克肝匀浆ATP含量(10-8μmol/L)减低(2.40±0.54vs2.96±0.43,P>0.05,2.26±0.55vs3.00±0.42,P<0.05和1.74±0.45vs2.79±0.40,P<0.01).肝SCD-1mRNA表达与ATP含量呈正相关(r=0.46,P<0.05).结论:长期高脂饮食引起肝SCD-1的表达下调,促使脂肪在肝内蓄积形成非酒精性脂肪肝.同时使肝细胞内饱和游离脂肪酸增加,线粒体结构和功能受损,使ATP的合成和储存下降,加重氧化应激对肝细胞的打击和肝脏的炎症反应.     

中药肠炎清治疗小鼠葡聚糖硫酸钠所致结肠炎的机制

目的:探讨肠炎清的疗效及其机制.方法:以葡聚糖硫酸钠(DSS)饮水法复制小鼠实验性结肠炎40只,随机平均分为4组:肠炎清中药组、柳氮磺胺吡啶(SASP)西药组、肠炎清和SASP中西药结合组和模型组.观察肠炎清(灌胃剂量为0.2mL/(20g?d)、1次/d、疗程7d)对疾病活动指数(DAI)和肠组织髓过氧化物酶(MPO)活性及TNF-α、IL-1β和IL-6mRNA表达的影响.结果:与模型组相比,肠炎清可降低DAI(1.413±0.835vs2.167±0.911,P<0.05)和MPO活性(72.4±0.590nkat/gvs117.0±0.902nkat/g,P<0.05),并降低肠组织TNF-α(0.841±0.190vs1.320±0.282,P<0.05)、IL-1β(0.641±0.095vs0.920±0.082,P<0.05)和IL-6mRNA(1.241±0.247vs1.620±0.312,P<0.05)的表达,中西医结合组以上指标下降更为明显(DAI:0.608±0.449;MPO:27.3±0.211;TNF-α:0.339±0.081;IL-1β:0.239±0.073;IL-6:0.639±0.141)(P<0.01).肠炎清与柳氮磺胺吡啶(SASP)的作用相当(P>0.05).结论:肠炎清可治疗DSS结肠炎,其降低肠组织TNF-α、IL-1β和IL-6mRNA的表达可能是其疗效机制之一.     

急性肝损伤大鼠肝脏血红素加氧酶-1/一氧化碳系统的变化及意义

目的:研究急性肝损伤时大鼠肝脏HO-1/CO系统的变化规律,探讨HO-1和内源性CO的作用机制及其病理生理意义.方法:采用D-氨基半乳糖(GalN)和脂多糖(LPS)联合腹腔注射制备大鼠急性肝损伤模型,动态测定各时间点(3,6,12,24,36 h)大鼠肝脏HO-1活性和蛋白表达情况,测定肝脏CO浓度以及血清ALT,AST水平和肝组织SOD活性、MDA含量变化.结果:Ga1N和LPS联合注射成功诱导了大鼠急性肝损伤,表现为染毒24 h时大鼠血清ALT,AST水平以及肝组织MDA浓度显著升高(10872.5±708.5 nkat/L,9246.8±814.7 nkat/L,5.06±1.21 μmol/g vs 1043.5±247.4 nkat/L,1278.6±273.8 nkat/L,2.03±0.59 μmol/g,均P＜0.01),SOD活性明显下降(813.7±168.3nkat/mg vs 1248.2±84.9 nkat/mg,P＜0.01),HE染色显示肝细胞出现严重损伤.染毒3-24 h大鼠肝脏HO-1活性明显增强,6-24 h呈现一定的时间依赖方式(4.02±0.74,5.97±1.51,6.13±1.18 μmol/g vs 2.86±0.41 μmol/g);Westernblot测定结果亦显示,HO-1蛋白表达显著增强,24 h时明显高于正常对照组(1.87±0.39 vs0.37±0.09,P＜0.01).正常大鼠肝脏的CO浓度极低,染毒后以时间依赖方式开始升高,并显著高于正常对照组(0.373±0.112,0.474±0.152,0.513±0.193 μmol/g vs 0.172±0.041 μmol/g,P＜0.01),这与HO-1表达情况相一致.结论:大鼠急性肝损伤时出现HO-1活性增加和蛋白表达持续上调以及CO浓度迅速增高,提示HO-1/CO系统参与急性肝损伤的病理生理过程,其表达增加可能对机体有重要调节作用.     

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.     

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.