小鼠腹水中弓形虫排泄分泌抗原鼻内免疫小鼠诱导的免疫应答

目的观察弓形虫感染小鼠腹水中分离的排泄-分泌抗原（excreted/secreted antigens,ESA）鼻内免疫小鼠对不同粘膜部位和系统的免疫效应。方法将5～6周龄BALB/c小鼠随机分为4组,每组10只,实验组分别用从感染弓形虫后24、48、72 h小鼠腹水中提取的ESA 20μg/只鼻内免疫小鼠2次,间隔2周;对照组用20μl/只PBS滴鼻。观察小鼠健康和死亡情况,记录体重。末次免疫后第3周处死小鼠,计数PP（Peyer’s patches）个数;分离PP淋巴细胞、脾淋巴细胞、小肠上皮内淋巴细胞（intraepithelial lymphocyte,IEL）及肠系膜淋巴结细胞（mesenteric lymph node lympho-cyte,MLNL）并计数。眼眶采血和收集直肠内粪便,ELISA检测血清特异性IgG水平及粪便sIgA。结果72 h ESA组小鼠免疫后健康状况较差,体重逐渐降低,死亡4只;其他组小鼠体重仍呈增高趋势。各实验组小鼠IEL、MLNL、脾淋巴细胞以及PP淋巴细胞的增殖活性均高于对照组（P〈0.05）,72 h和48 h ESA组高于24 h ESA组（P〈0.01）。免疫后第3周,各实验组小鼠血清IgG、粪便sIgA水平均高于对照组（P〈0.05）,72 h和48 h ESA组高于24 h ESA组（P〈0.01）。结论感染后不同时间提取的腹水弓形虫ESA鼻内免疫小鼠均可诱导不同粘膜部位及系统特异性的免疫应答,48 h ESA的免疫效果最好。     

不同剂量弓形虫ESA鼻内免疫小鼠诱导的粘膜及系统免疫应答

目的观察不同剂量弓形虫排泄一分泌抗原（excreted／secreted antigens，ESA）鼻内免疫小鼠诱导的粘膜及系统免疫应答，确定适宜免疫剂量。方法40只BALB／c小鼠，雌雄各半，随机分为5组，每组8只。分别用5、10、20和30μg ESA滴鼻免疫小鼠2次，间隔14d，对照组用20μl/只PBS滴鼻。于末次免疫后第14d，颈椎脱臼处死小鼠，ELISA法检测鼻咽冲洗液和小肠冲洗液sIgA、血清IgG抗体水平，分离并计数肠上皮内淋巴细胞（intest inalintraepithelial lymphocytes，iIEL）、肠系膜淋巴结淋巴细胞（mesenteric lymph node lymphocytes，MLNL）及脾淋巴细胞。结果实验期间，小鼠健康状况良好。随鼻内免疫ESA剂量的增加，特异性抗体水平不同程度的升高，MLNL、iIEL及脾淋巴细胞也显示不同程度的增生性应答。其中，30μg组小鼠血清IgG、脾淋巴细胞数量与10μg组、5μg组和PBS组比较，差异有统计学意义（P〈0．05或P〈0．01）；30μg组小肠冲洗液sIgA、鼻咽冲洗液sIgA、iIEL和MLNL数量，20μg组小肠冲洗液sIgA和MLNL数量与5／2g组及PBS组比较，差异有统计学意义（P〈0．05或P〈0．01）；20μg组血清IgG与PBS组比较差异有统计学意义（P〈0．05）。结论20μg和30μg ESA鼻内免疫能有效诱导粘膜及系统免疫应答。     

霍乱毒素联合弓形虫排泄-分泌抗原鼻内免疫小鼠诱导的GALT和NALT黏膜免疫应答

目的观察霍乱毒素(CT)联合弓形虫排泄-分泌抗原(ESA)鼻内免疫小鼠诱导的肠相关淋巴组织(GALT)和鼻相关淋巴组织(NALT)黏膜部位的免疫应答。方法将48只5~6周龄BABL/c小鼠随机均分为3组,分别用PBS、ESA和CT+ESA滴鼻免疫小鼠2次,间隔2周。末次免疫后14 d,处死小鼠,ELISA测定小鼠粪便和鼻咽冲洗液sIgA抗体水平;计数派伊尔淋巴集结(PP)、肠上皮淋巴细胞(IEL)、NALT和鼻通道(NC)淋巴细胞数,免疫细胞化学法检测CD4+、CD8+T细胞亚群水平。结果免疫后14 d,CT+ESA组小鼠鼻咽冲洗液和粪便sIgA水平显著高于ESA组和PBS组(P<0.01);CT+ESA和ESA组小鼠GALT部位的PP淋巴细胞显著增生,主要以CD4+T细胞为主;而IEL以CD8+T细胞增生为主,CD4+/CD8+比值降低(P<0.05)。CT+ESA NALT内淋巴细胞明显增生。CT+ESA组NC淋巴细胞显著升高(P<0.01),以CD4+T细胞增生为主。结论 CT佐剂联合ESA滴鼻免疫BALB/c小鼠可诱导GALT和NALT黏膜部位免疫应答。     

不同剂量霍乱毒素联合弓形虫ESA小鼠鼻内免疫的佐剂效应

目的观察不同剂量霍乱毒素(cholera toxin,CT)联合弓形虫排泄-分泌抗原(excreted-secreted antigens,ESA)滴鼻免疫小鼠的佐剂效应,探索CT作为鼻黏膜佐剂的适宜剂量。方法 5~6周龄BALB/c小鼠60只,随机分为5组,每组12只,分别以0、0.5、1.0、1.5或2.0μg CT联合ESA 20μg滴鼻免疫小鼠,间隔2周进行加强免疫,共2次。末次免疫后30 d,眼静脉丛采血并颈椎脱臼处死小鼠,用ELISA法检测血清IgG和粪便sIgA水平。分离脾、Peyer’s patch(PP)、肠系膜淋巴结(MLN)淋巴细胞。结果 1.5和2.0μg CT组小鼠健康状况下降、存活率降低。免疫后30 d,小鼠粪便sIgA水平随CT剂量的增加而升高,1.0、1.5和2.0μg CT组小鼠粪便sIgA水平显著高于无佐剂组(P0.05),3组间差异无统计学意义(P0.05)。CT联合ESA鼻内免疫小鼠后MLN、PP和脾淋巴细胞数显著高于无佐剂组(P0.05),并均呈现一定的剂量效应,但较高剂量组(1.0、1.5和2.0μg)之间差异无统计学意义(P0.05)。结论 1.0μg CT联合ESA鼻内免疫小鼠可诱导较高水平的黏膜和系统免疫应答,且对小鼠的健康无不良影响。     

重组人IL-2联合STAg鼻内免疫BALB/c小鼠诱导的免疫应答

目的观察重组人白细胞介素-2（rhuIL-2）联合弓形虫可溶性速殖子抗原（STAg）滴鼻免疫小鼠诱导的免疫应答,探讨rhuIL-2的佐剂效应及适宜剂量。方法5～6周龄BALB/c小鼠60只,随机分为6组,每组10只。实验组以STAg20μg或分别加rhuIL-2250、500、1000、2000 IU滴鼻免疫,抗原与佐剂溶于20μlPBS中,对照组以PBS滴鼻,免疫2次,间隔2周。末次免疫后30d,颈椎脱臼处死全部小鼠,ELISA法检测血清IgG和粪便sIgA水平;分离脾淋巴细胞、肠上皮内淋巴细胞（iIEL）,并计数。结果与PBS组相比,各佐剂组血清IgG水平都有增高,其中STAg＋500 IU IL-2组IgG水平增高最显著（P〈0.01）;STAg＋500 IU IL-2组和STAg＋1000 IU IL-2组粪便sIgA抗体水平显著高于PBS组和STAg组（P〈0.05）。联合IL-2佐剂免疫小鼠脾淋巴细胞和产生了增殖性应答,其中STAg＋500 IU IL-2组和STAg＋1000 IU IL-2组脾淋巴细胞数显著高于PBS组和STAg组（P〈0.05）;TAg＋500 IU IL-2组iIEL高于PBS组（P〈0.05）。结论rhuIL-2作为佐剂联合STAg鼻内免疫小鼠可有效诱导粘膜免疫、系统的细胞免疫和体液免疫应答;500 IU IL-2为鼻内免疫小鼠的适宜剂量。     

弓形虫STAg不同途径免疫小鼠诱导的黏膜免疫和系统免疫应答动态变化

目的动态观察弓形虫可溶性速殖子抗原(soluble tachyzoite antigen,STAg)滴鼻和皮下免疫小鼠诱导的黏膜免疫和系统免疫应答。方法6周龄BALB/c小鼠90只随机分为3组,分别以20μg STAg滴鼻或皮下注射免疫小鼠2次,间隔2周,对照组不做处理。末次免疫后1、2、3、4和5周,每组随机处死6只小鼠。ELISA法测定小肠冲洗液sI-gA和血清IgG,分离并计数小肠上皮内淋巴细胞(intraepithelial lymphocyte,IEL)和脾淋巴细胞。结果对照组小鼠小肠冲洗液sIgA水平和IEL数及血清IgG水平和脾淋巴细胞数均维持在较低水平。滴鼻免疫组小鼠小肠冲洗液sIgA水平升高,与对照组比较差异有统计学意义(FsIgA=10.074,FIEL=14.747,P0.01),其中第5周sIgA水平、第2~5周IEL数量与皮下免疫组比较差异有统计学意义(FsIgA=7.862,FIEL=9.807,P0.05)。皮下免疫组小鼠血清IgG水平和脾淋巴细胞数均升高,与对照组比较差异有统计学意义(FIgG=8.207,F脾细胞=11.209,P0.05),第5周脾淋巴细胞数与滴鼻组比较差异有统计学意义(F=6.826,P0.05)。结论20μg STAg滴鼻免疫小鼠诱导的黏膜免疫应答水平优于同剂量的皮下免疫,同时也诱导了较高水平的系统免疫应答。皮下免疫可诱导较高水平的系统免疫应答,但其诱导的黏膜免疫应答较弱。     

弓形虫复合黏膜疫苗鼻内免疫小鼠抵抗弓形虫感染作用的观察

目的 观察弓形虫复合黏膜疫苗鼻内免疫小鼠诱导的肠黏膜和系统免疫应答及其抗弓形虫感染作用。方法 BALB/c小鼠52只随机分为两组（每组26只），免疫组小鼠用弓形虫复合黏膜疫苗（每毫升含可溶性速殖子抗原1 mg， 霍乱毒素50 μg） 20 μl/只滴鼻免疫2次，间隔2周；对照组用等剂量PBS滴鼻。末次免疫后14 d，各组处死6只，摘眼球取血（0.5～1 ml）；取直肠内粪便（4～5粒），ELISA测定血清IgG和粪IgA抗体；分别计数脾组织、派伊尔集合淋巴结（PP）和肠上皮淋巴细胞（IEL），免疫细胞化学法检测各组织中CD4⁺、CD8⁺ T细胞亚群水平。用RH株弓形虫速殖子（4×10⁴个/只）灌胃攻击感染各组其余小鼠，30 d后颈椎脱位处死，计数肝、脑组织速殖子虫荷。 结果 免疫后14 d，免疫组小鼠血清IgG和粪IgA抗体水平（分别为0.224和0.371），显著高于对照组（分别为0.041和0.037）（P<0.05），脾、PP和IEL中T淋巴细胞与对照组相比明显增生（P<0.01），其中脾、PP中CD4⁺、CD8⁺ T淋巴细胞增殖显著（P<0.05），IEL中以CD8⁺ T细胞为主，增殖显著（P<0.01），CD4⁺/CD8⁺ 比值降低（P<0.05）。攻击后30 d，免疫组小鼠存活率（85.0%）显著高于对照组（45.0%）（P<0.05）。免疫组肝、脑组织速殖子数比对照组分别减少86.3%、86.7%，两组差异有统计学意义（P<0.05）。 结论 弓形虫复合黏膜疫苗鼻内免疫小鼠，能有效诱导黏膜和系统免疫应答，小鼠存活率显著提高，肝、脑组织虫荷显著降低。     

不同剂量STAg滴鼻免疫小鼠诱导的抗弓形虫感染作用

目的观察不同剂量可溶性速殖子抗原(soluble tachyzoite antigen,STAg)滴鼻免疫小鼠诱导抗弓形虫感染作用,确定STAg滴鼻免疫最佳剂量。方法BALB/c小鼠50只随机分为5组,实验组分别用5μg、10μg、20μg、30μg STAg/只滴鼻免疫小鼠2次,间隔2周,对照组用PBS滴鼻。末次免疫后第14d,用4×104个速殖子/只灌胃攻击全部小鼠,观察小鼠健康和死亡情况,记录体重。攻击后第30d检测粪便IgA和血清IgG,计数脾、脑组织内弓形虫速殖子,分离并计数小肠上皮内淋巴细胞(intraepithelial lymphocyte,IEL)。结果20μg和30μg组小鼠存活率高于5μg、10μg及对照组。攻虫后对照组小鼠体重逐渐降低,而5μg组,10μg组(P<0.05),20μg组(P<0.05)和30μg组(P<0.05)小鼠体重仍呈增高趋势。20μg和30μg组脾、脑组织内虫荷(速殖子数)显著低于5μg、10μg组和对照组(P<0.05),实验组粪便IgA,血清IgG及IEL数量高于对照组。结论不同剂量STAg滴鼻免疫小鼠均可诱导抗弓形虫感染,20μg或30μgSTAg滴鼻免疫可诱导更有效的抗弓形虫感染保护作用     

弓形虫排泄-分泌抗原和可溶性速殖子抗原免疫原性的观察

目的观察弓形虫速殖子排泄-分泌抗原（excreted/secreted antigen,ESA）和可溶性速殖子抗原（soluble tachyzoite antigen,STAg）鼻内免疫小鼠的免疫原性。方法BALB/c小鼠随机分为4组,分别用PBS 20μl/只、体外排泄-分泌抗原（excreted/secreted antigenin vitro,ESAv）、腹腔排泄-分泌抗原（excreted/secreted antigen in mice,ESAm）和STAg各20μg/只鼻内免疫2次,间隔14 d。分别于末次免疫后14 d和44 d每组处死8只小鼠,计数肠上皮内淋巴细胞（intestinal intraepithelial lymphocytes,iIEL）和脾淋巴细胞,ELISA法检测血清IgG和小肠冲洗液sIgA抗体水平。结果实验期间,ESAm组小鼠于二次免疫后状态欠佳,其他各组小鼠健康状况良好。末次免疫后14 d,各抗原组脾淋巴细胞及iIEL均增殖活跃,细胞数与PBS组比较,差异具统计学意义（P〈0.05或P〈0.01）;至免疫后44 d,两种ESA组脾淋巴细胞及iIEL数与PBS组比较差异具统计学意义（P〈0.05）。各抗原组血清IgG水平在免疫后14 d和44 d均明显增高,与PBS组比较差异有统计学意义（P〈0.05或P〈0.01）。免疫后14 d肠液sIgA水平ESAv、ES-Am和STAg组与PBS组比较差异有统计学意义（P〈0.05或P〈0.01）,ESAm和STAg组与ESAv组比较差异有统计学意义（P〈0.05或P〈0.01）,两种ESA组在免疫后44 d与PBS组比较差异仍具统计学意义（P〈0.05）。结论ESAv、ESAm和STAg鼻内免疫均可诱导粘膜及系统的细胞和体液免疫应答,有较强的免疫原性。但ESAm可能对机体有毒副作用,不适宜直接鼻内免疫。     

弓形虫STAg联合IFN-γ佐剂滴鼻免疫小鼠诱导不同黏膜部位抗体水平动态观察

目的观察弓形虫可溶性速殖子抗原（soluble tachyzoite antigen,STAg）联合IFN-γ佐剂滴鼻免疫BALB/c小鼠后不同黏膜部位抗体水平及其持续时间,为黏膜疫苗研制提供实验依据。方法 84只5~6周龄BALB/c小鼠随机分为免疫组和对照组,每组42只。免疫组以STAg（20μg/只）为抗原加IFN-γ（1 000 U/只）为佐剂滴鼻免疫,对照组以PBS 20μl滴鼻。共滴鼻2次,间隔2周。首次免疫后第0、2、4、6、8、10、12周每组处死6只小鼠,ELISA法测定鼻咽、肺和小肠冲洗液sIgA、IgG水平。结果小鼠用弓形虫STAg联合IFN-γ首次免疫后鼻咽冲洗液sIgA和IgG水平均增高,其中第2、4、6、8周sIgA水平显著高于对照组（P〈0.05）,第2、4、6周IgG水平高于对照组（P〈0.05）;首次免疫后第6、8周小鼠肺冲洗液sIgA水平显著高于对照组（P〈0.05）,第4、6、8周IgG水平高于对照组（P〈0.05）;首次免疫后第2、4、6周小肠冲洗液sIgA水平高于对照组（P〈0.05）,第2、4、6、8周IgG水平高于对照组（P〈0.05）。免疫后不同黏膜部位抗体均以sIgA为主,且以肠道冲洗液最高。结论 STAg联合IFN-γ佐剂滴鼻免疫BALB/c小鼠可诱导鼻咽、肺和小肠黏膜部位产生高水平sIgA和IgG抗体应答,并可持续6~8周。表明滴鼻免疫是弓形虫疫苗的适宜接种途径。     

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.