Screening for intellectual disabilities and borderline intelligence in Dutch outpatients with severe mental illness.

BACKGROUND: The reliability and validity of the Screener for Intelligence and Learning Disabilities (SCIL) are unknown in a population of outpatients with severe mental illness. The prevalence of mild or borderline intellectual disabilities (MBID); an umbrella term for people with borderline intellectual functioning (BIF) and mild intellectual disability (MID) in this population is also unknown. METHODS: A total of 625 patients were screened with the SCIL, 201 of which also had IQ test results. RESULTS: Cronbach's alpha of the SCIL was 0.73. The AUC value for detecting MBID was 0.81, and also 0.81 for detecting MID, with percentages of correctly classified subjects (when using the advised cut-off scores) being 73% and 79%, respectively. The SCIL results suggested that 40% of the patients were suspected of MBID and 20% of MID. CONCLUSION: The SCIL seems to be an appropriate screening tool for MBID. It is important to screen for MBID because a substantial proportion of outpatients with severe mental illness appear to be functioning at this level. It is necessary to adapt treatment for these patients.

Cardiac Ultrasound Findings in Infants with Severe (Hurler Phenotype) Untreated Mucopolysaccharidosis (MPS) Type I.

BACKGROUND: Serious cardiac valve disease and left ventricular hypertrophy occur in most untreated older children with severe mucopolysaccharidosis type I. Although it is assumed that early intervention prevents these processes, evaluation of cardiac findings in these infants has not yet been reported. METHODS: We reviewed echocardiograms of 13 untreated infants < 1 year of age with severe mucopolysaccharidosis type I who had undergone evaluation for hematopoietic cell transplantation. We recorded left ventricular chamber dimensions, septal and posterior wall thicknesses, ventricular function, and aortic sinus diameters. We evaluated mitral and aortic valves for increased thickness, regurgitation, and stenosis. RESULTS: Average age (7M, 6F) was 221 (range 25-347) days. Left ventricular chamber dimension was ≥2 SD of normal in 3/13; wall thicknesses were ≥2 SD of normal in 2/13 infants. Systolic function was normal. Mitral valves were thickened in all infants; mitral regurgitation was present in 9/13, but significant in only three infants. Aortic valves were thickened in 10/13, but no infant had significant aortic regurgitation. Neither mitral nor aortic stenosis occurred. Aortic roots were dilated to ≥2 SD of normal in 5/13. CONCLUSIONS: Characteristic cardiac features of severe mucopolysaccharidosis type I can be seen in infancy. Mitral and aortic valve thickening are nearly universally present, even in the youngest infants. In 20-30 % of infants, other abnormalities such as left ventricular dilation, increased wall thickness, and mild mitral/aortic regurgitation may occur. Aortic root dilation is a frequent finding. Early intervention with enzyme replacement therapy may minimize the incidence and severity of cardiac findings in these infants. SUMMARY: Serious cardiac valve disease and left ventricular hypertrophy occur in most untreated older children with severe mucopolysaccharidosis type I. Although it is assumed that early intervention prevents these processes, evaluation of cardiac findings in these infants has not yet been reported. In our study of 13 infants with severe untreated MPS I < 1 year of age, mitral and aortic valve thickening was nearly universally present and aortic root dilation was frequent. Despite this, we found a lower incidence of left ventricular hypertrophy and both a lower incidence and milder expression of mitral and aortic valve dysfunction than previously reported in older children. These findings suggest that earlier intervention, including neonatal screening, may be of benefit to children with severe MPS I.

Weight loss in overweight patients maintained on atypical antipsychotic agents.

BACKGROUND: Weight gain and associated medical morbidity offset the reduction of extrapyramidal side effects associated with atypical antipsychotics. Efforts to control weight in antipsychotic-treated patients have yielded limited success. METHODS: We studied the impact of an intensive 24-week program of diet, exercise, and counseling in 17 chronically psychotic patients (10 women, seven men) who entered at high average body weight (105.0+/-18.4 kg) and body mass index (BMI) (36.6+/-4.6 kg/m(2)). A total of 12 subjects who completed the initial 24 weeks elected to participate in an additional 24-week, less intensive extension phase. RESULTS: By 24 weeks, weight-loss/patient averaged 6.0 kg (5.7%) and BMI decreased to 34.5 (by 5.7%). Blood pressure decreased from 130/83 to 116/74 (11% improvement), pulse fell slightly, and serum cholesterol and triglyceride concentrations changed nonsignificantly. With less intensive management for another 24 weeks, subjects regained minimal weight (0.43 kg). CONCLUSIONS: These findings add to the emerging view that weight gain is a major health problem associated with modern antipsychotic drugs and that labor-intensive weight-control efforts in patients requiring antipsychotic treatment yield clinically promising benefits. Improved treatments without weight-gain risk are needed.

Delirium during clozapine treatment: incidence and associated risk factors.

BACKGROUND: Incidence and risk factors for delirium during clozapine treatment require further clarification. METHODS: We used computerized pharmacy records to identify all adult psychiatric inpatients treated with clozapine (1995-96), reviewed their medical records to score incidence and severity of delirium, and tested associations with potential risk factors. RESULTS: Subjects (n = 139) were 72 women and 67 men, aged 40.8 +/- 12.1 years, hospitalized for 24.9 +/- 23.3 days, and given clozapine, gradually increased to an average daily dose of 282 +/- 203 mg (3.45 +/- 2.45 mg/kg) for 18.9 +/- 16.4 days. Delirium was diagnosed in 14 (10.1 % incidence, or 1.48 cases/person-years of exposure); 71.4 % of cases were moderate or severe. Associated factors were co-treatment with other centrally antimuscarinic agents, poor clinical outcome, older age, and longer hospitalization (by 17.5 days, increasing cost); sex, diagnosis or medical co-morbidity, and daily clozapine dose, which fell with age, were unrelated. CONCLUSIONS: Delirium was found in 10 % of clozapine-treated inpatients, particularly in older patients exposed to other central anticholinergics. Delirium was inconsistently recognized clinically in milder cases and was associated with increased length-of-stay and higher costs, and inferior clinical outcome.

Effect of highly active antiretroviral therapy on the natural history of anal squamous intraepithelial lesions and anal human papillomavirus infection.

The effect of highly active antiretroviral therapy (HAART) on the natural history of anal squamous intraepithelial lesions (ASIL)-the likely anal cancer precursor-and anal human papillomavirus (HPV) infection is unknown. ASIL severity and level of anal HPV DNA were evaluated among HIV-positive men who have sex with men (MSM) for at least 6 months before initiation of HAART. The results were compared with those from a 6-month period after initiation of HAART. Anal swabs for cytology and HPV studies were obtained, followed by high-resolution anoscopy and biopsy. Among men whose most severe pre-HAART diagnosis was atypical squamous cells of undetermined significance or low-grade ASIL, 18% (confidence interval [CI], 6-31%, 7 of 38) progressed and 21% (CI, 8-34%, 8 of 38) regressed 6 months after starting HAART. Seventeen percent (CI, 0-38%, 2 of 12) of study subjects who began with a normal diagnosis developed ASIL. Only 4% (CI, 0-10%, 1 of 28) of study subjects with high-grade ASIL regressed to normal. There was no reduction in the proportion of study subjects who tested positive for HPV DNA or HPV DNA levels after HAART initiation. The ASIL and HPV data were similar to those of the pre-HAART comparison period. These results indicate that HAART has little effect on either ASIL or HPV in the first 6 months after HAART initiation.

Body morphology and the speed of cutaneous rewarming.

BACKGROUND: Infants and children cool quickly because their surface area (and therefore heat loss) is large compared with their metabolic rate, which is mostly a function of body mass. Rewarming rate is a function of cutaneous heat transfer plus metabolic heat production divided by body mass. Therefore, the authors tested the hypothesis that the rate of forced-air rewarming is inversely related to body size. METHODS: Isoflurane, nitrous oxide, and fentanyl anesthesia were administered to infants, children, and adults scheduled to undergo hypothermic neurosurgery. All fluids were warmed to 37 degrees C and ambient temperature was maintained near 21 degrees C. Patients were covered with a full-body, forced-air cover of the appropriate size. The heater was set to low or ambient temperature to reduce core temperature to 34 degrees C in time for dural opening. Blower temperature was then adjusted to maintain core temperature at 34 degrees C for 1 h. Subsequently, the forced-air heater temperature was set to high (approximately 43 degrees C). Rewarming continued for the duration of surgery and postoperatively until core temperature exceeded 36.5 degrees C. The rewarming rate in individual patients was determined by linear regression. RESULTS: Rewarming rates were highly linear over time, with correlations coefficients (r2) averaging 0.98+/-0.02. There was a linear relation between rewarming rate (degrees C/h) and body surface area (BSA; m2): Rate (degrees C/h) = -0.59 x BSA (m2) + 1.9, r2 = 0.74. Halving BSA thus nearly doubled the rewarming rate. CONCLUSIONS: Infants and children rewarm two to three times faster than adults, thus rapidly recovering from accidental or therapeutic hypothermia.

Left iliac vein occlusion: its clinical spectrum.

The cases reported here demonstrate the variability of the clinical manifestations of left common iliac venous occlusive disease. In each instance, therapy must be adjusted to meet the symptomatic needs of the individual patient. The experience reported here should reinforce the fact that occlusions even 25 months or longer in duration may be reopened. Continuing patency can be enhanced by stent placement.

Transcatheter closure of membranous ventricular septal defects with a new nitinol prosthesis in a natural swine model.

Transcatheter closure of a membranous ventricular septal defect (MVSD) is much more difficult than closure of other intracardiac defects because of the proximity to the aortic and tricuspid valves and their relatively large size in small children. In this report, transcatheter closure of naturally occurring membranous VSDs was attempted in 12 Yucatan minipigs. The prosthesis is constructed from fine Nitinol wires in the shape of two buttons and a connecting waist filled with polyester fiber. Two kinds of prosthesis were used in this study: concentric and eccentric left-sided retention disks. A 6 or 7 Fr delivery sheath was advanced across the membranous VSD over a wire from femoral vein. The prosthesis was inserted through the sheath by pushing the delivery cable to deploy a button into left ventricle and the second button was then deployed into right ventricle by withdrawing the sheath. Successful implantation of the device was achieved in all animals except one. Complete closure rate was 58.3% immediately after placement, 100% at 1 week, 90.9% at 1 month and 3 months, and 100% at 6 months. An associated aneurysm of the membranous septum increased significantly in size in two of three animals using the concentric device, and in none of the animals using the eccentric device. A trace to mild aortic regurgitation was present in two of the three animals using the concentric device, and only in one of the eight animals using the eccentric device. Five animals developed a trace to mild tricuspid regurgitation. Pathologic examination showed all devices to be covered by smooth neoendothelium at 3 months. This report presents the first experimental study where closure of membranous ventricular septal defects in a swine model was attempted by specially constructed devices. Procedural success and occlusion rates are very encouraging but overall results cannot equal surgery. Further experimentation is needed with devices that are redesigned according to the experience gained from this study.

Echocardiographic diagnosis of heart disease in apparently healthy adolescents.

OBJECTIVE: Comprehensive data are currently unavailable on the prevalence of cardiac abnormalities in children after the newborn/infant period. The present report describes the prevalence of echocardiographically detected cardiac disease in a cohort of randomly selected healthy junior high school children. METHODS: The cohort for this report consists of 357 children (mean age: 13 years) randomly selected after blood pressure screening of 12 043 fifth through eighth grade students and having an echocardiographic examination as part of a study of insulin resistance in childhood. RESULTS: A physical examination performed by a board-certified pediatrician reported no cardiac abnormalities. However, echocardiography and Doppler studies identified 13 (3.6%) children (7 males and 6 females), with previously unknown cardiac abnormalities, as follows: abnormal mitral valve with mitral regurgitation (4), bicuspid aortic valve (2), atrial septal defect (2), coronary artery to pulmonary artery fistula (1), patent ductus arteriosus (1), pulmonary hypertension (1), cardiomyopathy (1), and pulmonary artery stenosis (1). Physical examination performed by a pediatric cardiologist detected abnormal cardiac findings in 7 (54%) of the children. Cardiac catheterization was required in 3 for additional diagnostic evaluation and in 2 for therapeutic intervention; 1 patient underwent open-heart surgery. Bacterial endocarditis prophylaxis was recommended in 8 (62%) of the 13 children. CONCLUSIONS: The results suggest that: 1) clinically significant cardiac disease in childhood is more prevalent than previously reported; and 2) improved screening methods should be considered to detect asymptomatic but significant cardiac abnormalities that may result in long-term complications. echocardiography, prevalence, incidence, heart disease, children.

New device for closure of muscular ventricular septal defects in a canine model.

BACKGROUND: Repair of muscular ventricular septal defects (MVSDs) has always been challenging to the surgeon. Long-term morbidity and mortality are significantly increased if the defects are closed via left ventriculotomy or if they are associated with other complex congenital anomalies. The purpose of this study was to close MVSDs with the Amplatz ventricular septal defect device. This device is constructed from 0.004-in nitinol wire mesh filled with polyester fibers. It is retrievable, repositionable, self-centering, and of low profile. METHODS AND RESULTS: MVSDs were created with the help of a sharp punch in 10 dogs. The location of the defects was anterior muscular (n=3), midmuscular (n=3), apical (n=3), and inlet muscular (n=1). The diameter of the defects ranged from 6 to 14 mm. All defects were closed in the catheterization laboratory. The device was placed with the help of transesophageal echocardiography and fluoroscopy. A 7F sheath was used to deploy the device from the right ventricular side in 8 and the left ventricular side in 2 dogs. Placement was successful in all animals. The complete closure rate was 30% (3/10) immediately after placement and 100% at 1-week follow-up. Pathological examination of the heart revealed complete endothelialization of the device in dogs killed after 3 months. CONCLUSIONS: The Amplatz ventricular septal defect device appears highly efficacious in closing MVSDs. The advantages include a small delivery sheath, complete retrievability before release, and the fact that it is self-centering and self-expanding, thereby making it an attractive option in smaller children.

Perventricular [correction of Periventricular] closure of ventricular septal defects without cardiopulmonary bypass.

BACKGROUND: Minimally invasive techniques are currently in use to close atrial and ventricular septal defects (VSD). Cardiopulmonary bypass (CPB) is instituted via the femoral vessels, which may cause injury to these vessels, especially in younger patients. The objectives of this study were to demonstrate the feasibility of perventricular [corrected] closure of muscular VSD (MVSD) and paramembranous VSD (PVSD) without CPB, using the Amplatz VSD device. METHODS: Five Yucatan pigs with naturally occurring PVSD (3- to 7-mm diameter) and 5 dogs with surgically created MVSD (6- to 14-mm diameter) were subjects of this study. The VSDs were closed intraoperatively with a 7-French delivery sheath inserted through the free wall of the right (n = 5) or left ventricle (n = 5), under epicardial echocardiogram guidance. The animals were followed for 3 months. RESULTS: There was no operative mortality. All MVSD closed after placement of the device. Closure rate of PVSD was 4 of 5 after placement and 3 of 5 after 3 months. One pig developed aortic incompetence at the last follow-up. CONCLUSIONS: Perventricular closure of MVSD and PVSD is feasible. Avoidance of CPB can decrease recovery time, its complications, and trauma to the femoral vessels.

The effects of intentional hyperthermia on the Thrombelastograph and the Sonoclot analyser.

The effect of whole-body hyperthermia (WBH) on viscoelastic properties of whole blood, as measured by the thrombelastogram (TEG) and Sonoclot analyser, was investigated in 10 patients undergoing WBH-carboplastin therapy for metastatic disease. Blood was taken from an existing central line at baseline (37 degrees C), during warming (39 and 41 degrees C) and cooling (39 and 37 degrees C). Sonoclot and TEG samples were analysed simultaneously at 37 degrees C and at the patient's temperature with a temperature-compensated unit, except at 41 degrees C for the Sonoclot (maximum temperature adjustment of 40 degrees C). TEG measurements included R time (time to initial fibrin formation [mm]), K time (mm) and alpha angle (degrees) (both reflecting fibrinogen-platelet interaction), maximum amplitude (representing qualitative platelet function [mm]) and per cent fibrinolysis at 30 and 60 min. The Sonoclot ACT (SonACT-secs), initial rate of clot formation (%), time to peak amplitude (min) and peak amplitude of the Sonoclot signature (mm) were recorded. Decreased R time of the TEG compared to a marginally elevated baseline was found at all times during warming and cooling (p < 0.05). The K time was decreased at 41 degrees C compared to a normal baseline (p < 0.05). The SonACT was decreased (from an elevated baseline) at all other times, without differences in measures at patient temperature versus 37 degrees C (p < 0.05). The data suggest acceleration of fibrin formation during WBH to 41 degrees C in patients with malignancy. Implications for defining thromboembolic risk require further investigation.

Production of reovirus type-1 and type-3 from Vero cells grown on solid and macroporous microcarriers.

Two strains of reovirus were propagated in Vero cells grown in stationary or microcarriers cultures. Vero cells grown as monolayers on T-flasks or in spinner cultures of Cytodex-1 or Cultispher-G microcarriers could be infected with reovirus serotype 1, strain Lang (T1L), and serotype 3, strain Dearing (T3D). A regime of intermittent low speed stirring at reduced culture volume was critical to ensure viral infection of cells in microcarrier cultures. The virus titre increased by 3 to 4 orders of magnitude over a culture period of 150 h. Titres of the T3D reovirus strain were higher (43%) compared to those of the T1L strain in all cultures. Titres were significantly higher in T-flask and Cytodex-1 microcarrier cultures compared to Cultispher-G cultures with respect to either reovirus type. The viral productivity in the microcarrier cultures was dependent upon the multiplicity of infection (MOI) and the cell/bead ratio at the point of infection. A combination of high MOI (5 pfu/cell) and high cell/bead loading (>400 for Cytodex-1 and >1,000 for Cultispher-G) resulted in a low virus productivity per cell. However, at low MOI (0.5 pfu/cell) the virus productivity per cell was significantly higher at high cell/bead loading in cultures of either microcarrier type. The maximum virus titre (8.5 x 10(9) pfu/mL) was obtained in Cytodex-1 cultures with a low MOI (0.5 pfu/cell) and a cell/bead loading of 1,000. The virus productivity per cell in these cultures was 4,000 pfu/cell. The lower viral yield in the Cultispher-G microcarrier cultures is attributed to a decreased accessibility of the entrapped cells to viral infection. The high viral productivity from the Vero cells in Cytodex-1 cultures suggests that this is a suitable system for the development of a vaccine production system for the Reoviridae viruses.

A cost-construction model to assess the total cost of an anesthesiology residency program.

BACKGROUND: Although the total costs of graduate medical education are difficult to quantify, this information may be of great importance for health policy and planning over the next decade. This study describes the total costs associated with the residency program at the University of Texas--Houston Department of Anesthesiology during the 1996-1997 academic year. METHODS: The authors used cost-construction methodology, which computes the cost of teaching from information on program description, resident enrollment, faculty and resident salaries and benefits, and overhead. Surveys of faculty and residents were conducted to determine the time spent in teaching activities; access to institutional and departmental financial records was obtained to quantify associated costs. The model was then developed and examined for a range of assumptions concerning resident productivity, replacement costs, and the cost allocation of activities jointly producing clinical care and education. RESULTS: The cost of resident training (cost of didactic teaching, direct clinical supervision, teaching-related preparation and administration, plus the support of the teaching program) was estimated at $75,070 per resident per year. This cost was less than the estimated replacement value of the teaching and clinical services provided by residents, $103,436 per resident per year. Sensitivity analysis, with different assumptions regarding resident replacement cost and reimbursement rates, varied the cost estimates but generally identified the anesthesiology residency program as a financial asset. CONCLUSIONS: In most scenarios, the value of the teaching and clinical services provided by residents exceeded the cost of the resources used in the educational program.

Sudden asystole during craniotomy: unrecognized phenytoin toxicity.

The authors report a case of intraoperative sinus arrest in an otherwise healthy patient undergoing craniotomy for aneurysm clipping after mild subarachnoid hemorrhage. The sinus arrest was precipitated by a rapid infusion of 1500 mg phenytoin and was successfully treated with standard resuscitative measures. The differential diagnosis of intraoperative cardiac arrest and the mechanisms of action of phenytoin are discussed. The authors emphasize the role of phenytoin in cerebral protection.

Effects of hyperbaric hyperoxia on cardiac and regional hemodynamics in conscious dogs.

BACKGROUND: Although evidence of systemic vasoconstriction has been reported both in animal models and in humans, the regional hemodynamic effects of hyperbaric hyperoxia have not been well characterized. METHODS: In the present study, we report the effects of hyperoxia (normobaric and hyperbaric) on simultaneous measurements of cardiac and regional hemodynamics in the chronically instrumented conscious dog. RESULTS: Hyperbaric hyperoxia (202 kPa) produced significant decreases in heart rate (12%) and cardiac output (20%) and a significant increase in systemic vascular resistance (30%). Carotid artery blood flow decreased significantly (18%) whereas coronary, hepatic, renal and mesenteric flows remained unchanged. CONCLUSIONS: Our data show that the hyperoxic vasoconstriction is limited to the cerebral and peripheral vascular beds. Additionally, blood flow to major organs is well preserved in the face of hyperoxia-induced decreases in cardiac output. Consequently, we postulate that a redistribution of blood flow from peripheral vascular beds (e.g., skin, muscle, bone) to major organs occurs during hyperbaric hyperoxia.

Virologic, immunologic, and clinical parameters in the incidence and progression of anal squamous intraepithelial lesions in HIV-positive and HIV-negative homosexual men.

Anal cancer may be preceded by anal squamous intraepithelial lesions (ASIL), but the natural history of ASIL is poorly understood. In this report, we characterize the 2-year incidence and progression of low-grade SIL (LSIL) and high-grade SIL (HSIL) in a cohort study in 346 HIV-positive and 262 HIV-negative homosexual or bisexual men. Subjects were studied at defined intervals using anal cytology, anoscopy with biopsy of visible lesions, human papillomavirus (HPV) testing, HIV serostatus, CD4 level, and data on medical history and lifestyle. The incidence of HSIL within 2 years was 20% in HIV-positive men and 8% in HIV-negative men who were normal at baseline. In total, 62% of HIV-positive and 36% of HIV-negative men with LSIL at baseline progressed to HSIL. The relative risk (RR) for anal disease progression in HIV-positive men was 2.4 (95% confidence interval [CI], 1.8-3.2) when compared with HIV-negative men. The RR increased to 3.1 (95% CI, 2.3-4.1) in HIV-positive men with CD4 counts <200/mm3. Infection with multiple HPV types was a risk factor for anal disease progression in both HIV-positive (RR = 2.0; 95% CI, 1.0-4.1) and HIV-negative (RR = 5.1; 95% CI, 2.3-11) men. The incidence of anal HSIL and progression of LSIL to HSIL within 2 years of follow-up is high in HIV-positive homosexual or bisexual men and to a lesser extent, in HIV-negative men. Men with the above risk factors may be at increased risk of developing anal cancer.

Anal squamous intraepithelial lesions in HIV-positive and HIV-negative homosexual and bisexual men: prevalence and risk factors.

Anal cancer is more commonly found in homosexual and bisexual men than cervical cancer is in women. Invasive anal cancer may be preceded by anal squamous intraepithelial lesions (ASIL), and treatment of ASIL may prevent the development of anal cancer. We characterized the prevalence and risk factors for ASIL in 346 HIV-positive and 262 HIV-negative homosexual men. Anal cytology, biopsy of visible anal lesions, and human papillomavirus (HPV) tests were performed, and data on HIV serostatus, CD4 count, and medical and lifestyle history were collected. ASIL was diagnosed in 36% of HIV-positive men and 7% of HIV-negative men (relative risk [RR] = 5.7; 95% confidence interval [CI], 3.6-8.9). Among HIV-positive men, the RR for ASIL increased with lower CD4 levels but was elevated even in men with CD4 levels >500/mm3 (RR = 3.8; 95% CI, 2.1-6.7) when compared with HIV-negative men. High-level HPV infection, as measured by detection of both hybrid capture (HC) group A and group B types, was another significant risk factor for ASIL in both HIV-positive men (RR = 8.8; 95% CI, 2.3-35) and HIV-negative men (RR = 20; 95% CI, 5.5-71) when compared with HC-negative men. HIV-negative men with anal HPV infection and HIV-positive men, regardless of CD4 level, are at high risk for ASIL.

High incidence of anal high-grade squamous intra-epithelial lesions among HIV-positive and HIV-negative homosexual and bisexual men.

OBJECTIVE: The incidence of anal cancer among homosexual men exceeds that of cervical cancer in women, and HIV-positive homosexual men may be at even higher risk than HIV-negative men. Cervical cancer is preceded by high-grade squamous intra-epithelial lesions (HSIL) and anal HSIL may similarly be the precursor to anal cancer. In this study, we describe the incidence of and risk factors for HSIL in HIV-positive and HIV-negative homosexual and bisexual men. DESIGN: Prospective cohort study of HIV-positive and HIV-negative homosexual men. SETTING: The University of California, San Francisco. PATIENTS: 346 HIV-positive and 262 HIV-negative men enrolled at baseline, 277 HIV-positive and 221 HIV-negative homosexual men followed after baseline. STUDY DESIGN: A questionnaire was administered detailing lifestyle habits, medical history and sexual practices. Anal swabs for cytology and human papillomavirus studies were obtained, followed by biopsies of visible lesions. Human papillomavirus testing was performed using polymerase chain reaction (PCR) and 'hybrid capture'. Blood was obtained for HIV testing and measurement of CD4 levels. MAIN OUTCOME MEASURES: Incident HSIL. RESULTS: HIV-positive men were more likely to develop HSIL than HIV-negative men relative risk (RR), 3.7; 95% confidence interval (CI), 2.6-5.7. Life-table estimates of the 4-year incidence of HSIL was 49% (95% CI, 41-56) among HIV-positive men and 17% (95% CI, 12-23) among HIV-negative men. Among HIV-positive men, those with lower baseline CD4 counts (P = 0.007) and persistent infection with one or more human papillomavirus types, determined using PCR (P = 0.0001), were more likely to develop HSIL. CONCLUSIONS: HIV infection, lower CD4 levels and human papillomavirus infection were associated with high rates of incident HSIL among homosexual men. However, high rates were found at all CD4 levels among HIV-positive men and among HIV-negative men.