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Biomedical subjects

P Bacchetti

Publications and source records attributed to P Bacchetti.

At least 55 records · Page 3Linked to original sources
PubMed1997

The prevalence of serum antibody to human herpesvirus 8 (Kaposi sarcoma-associated herpesvirus) among HIV-seropositive and high-risk HIV-seronegative women.

OBJECTIVE: To determine the prevalence of human herpesvirus 8 (HHV-8) seropositivity among women who are known to be infected with human immunodeficiency virus type 1 (HIV-1) or who are at high risk for HIV infection. DESIGN: A cross-sectional and blinded study of the prevalence of serological reactivity to HHV-8 infection as determined by an indirect immunofluorescence assay using nuclei from cells latently infected with HHV-8. Data and specimens were collected at baseline assessments of a longitudinal natural history cohort study. SETTING: Four San Francisco Bay Area outpatient HIV specialty clinics participating in the cohort study. PATIENTS: A total of 387 participants in the Women's Interagency HIV Study whose HIV infection status was documented and serum was available in a local specimen repository. MAIN OUTCOME MEASURE: Serological reactivity to HHV-8. RESULTS: Serological reactivity to latent HHV-8 antigens was uncommon among study participants: 13 (3.4%) demonstrated serum antibodies. HHV-8 reactivity was more common among HIV-infected women; 12 (4.0%; 95% confidence interval [CI], 2.1%-6.9%) of the 302 HIV-infected participants vs 1 (1.2%; 95% CI, 0.03%-6.4%) of the 84 HIV-uninfected participants were seropositive for HHV-8, though the difference did not attain statistical significance (odds ratio=3.43; 95% CI, 0.49-148.6). Two of the HIV-infected women had Kaposi sarcoma lesions and both were seropositive. CONCLUSIONS: The prevalence of HHV-8 seropositivity among the group of HIV-infected women was dramatically lower than that recently reported among HIV-infected homosexual and bisexual men (30%-35%). This finding parallels the lower prevalence of Kaposi sarcoma among women in contrast to men with HIV infection. These data further extend the correlation of HHV-8 serological reactivity with risk of Kaposi sarcoma and are consistent with an important role for HHV-8 infection in development of Kaposi sarcoma.

Adult↗
PubMed1997

The impact of surgical complications after liver transplantation on resource utilization.

OBJECTIVE: To evaluate the impact of surgical complications on length of stay and hospital charges after liver transplantation. DESIGN: A retrospective economic evaluation of the outcomes during initial hospitalization after liver transplantation. SETTING: University hospital treating referred patients. PATIENTS: The study population was 109 patients undergoing 111 liver transplantations during fiscal year 1993. MAIN OUTCOME MEASURES: Hospital charges and length of stay during the initial hospitalization after liver transplantation. Multivariate regression methods were used to analyze the impact of surgical complications on costs. RESULTS: Of the 111 transplantations, 30 (27%) had a surgical complication that required a return to the operating room during the initial hospitalization. The effect of a surgical complication was to increase the mean hospital charges (excluding physician charges) from $150,092 to $347,728 (difference of mean, $197,636; confidence interval of difference, $114,153 to $319,326). The median length of stay was 16 days for patients without complications and 45 days for those with complications. Univariate and multivariate models suggested that surgical complications had the greatest effect on length of stay and hospital charges among the factors studied. Complications tended to occur more frequently among patients with United Network for Organ Sharing (UNOS) status 1 (42% vs 22%), but this did not reach statistical significance (P = .09). CONCLUSIONS: Surgical complications after liver transplantation have a marked impact on the cost of the procedure. The magnitude of this effect is greater than that of UNOS status, presence of rejection, or other demographic or clinical factors studied. Complications tend to occur in the most ill patients. Identifying strategies to reduce the risk of complications, particularly in patients with UNOS status 1, likely can reduce the cost of transplantation.

Adolescent↗
PubMed1997

Detection of extracapsular extension of prostate carcinoma with endorectal and phased-array coil MR imaging: multivariate feature analysis.

PURPOSE: To determine which magnetic resonance (MR) imaging features are most predictive of extracapsular extension of prostate carcinoma. MATERIALS AND METHODS: In 77 patients who had stage pT2 or pT3 prostate carcinoma, MR images were retrospectively reviewed by three readers with varying experience in interpretation of endorectal coil images of the prostate gland. MR imaging features assessed were broad tumor contact, smooth capsular bulge, irregular bulge, obliteration of the rectoprostatic angle, and asymmetry of the neurovascular bundle. Multivariate logistic regression analysis was performed to determine the relative value of each MR imaging feature. RESULTS: At multivariate analysis, obliteration of the rectoprostatic angle and asymmetry of the neurovascular bundle were most predictive of extracapsular extension, with a specificity of up to 95% and sensitivity of 38%. Poor-quality images reduced accuracy for all readers. The most experienced reader demonstrated overall accuracy of 77% in determination of extracapsular extension. CONCLUSION: Obliteration of the rectoprostatic angle and asymmetry of the neurovascular bundle were most indicative of extracapsular extension. Reader experience plays an important role in the ability to interpret prostate MR images and is an important contributor to interobserver variability.

Aged↗
PubMed1997

The underreporting of deaths of American Indian children in California, 1979 through 1993.

OBJECTIVES: This study linked birth and death certificates to determine misclassification of deaths of American Indian children in California. METHODS: Birth records for 1979 to 1993 were matched with mortality records through a computerized system. RESULTS: The number of deaths to American Indians was estimated to be three to four times greater than that reported on death certificates. Children in urban counties and those who died before 1987 were more likely to be misclassified. CONCLUSIONS: California death certificates identify less than one third of the deaths among American Indian children. Adjusting for racial misclassification provides a more accurate accounting of child mortality among American Indians.

Adolescent↗
PubMed1996

Reporting delays of deaths with AIDS in the United States.

The 1993 change in the AIDS case definition used in the United States has disrupted AIDS incidence trends. Death incidence is not disrupted by the change, but, like AIDS incidence, must be corrected for reporting delays. This article uses data from the national AIDS surveillance system to examine reporting delays of deaths with AIDS and finds (a) by mid-1994, death counts after two quarters of subsequent reporting seem to be 82% complete; (b) beginning in mid-1991, there is a significant trend toward faster reporting in more recent quarters, but this trend would be masked if very short delays were used in estimation; (c) persons dying in the quarter of diagnosis tend to have longer delays; (d) delays are more variable than assumed by standard methods, making uncertainty estimation difficult; and (e) delay corrections provided with the public data set may be too pessimistic.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Clozapine eligibility: the effect of stringent criteria on ethnic, gender and age subgroups of schizophrenic patients.

1. The purpose of this retrospective chart review study was to determine whether broad and stringent criteria differentially impact clozapine eligibility in ethnic, gender, and age subgroups of schizophrenic patients. 2. 505 patients charts were selected from a random cluster sample of mental health patients known to the city and county of San Francisco. Information related to clozapine eligibility was abstracted by trained non-clinical personnel. The impact of subgroup membership on eligibility was examined using logistic regression procedures. 3. Even under the broadest interpretation of FDA requirements for clozapine use, Asian patients were less likely to be eligible, since fewer Asian patients met clozapine treatment requirements. Under more stringent eligibility criteria, older patients were more likely to be excluded from eligibility when TD does not automatically satisfy treatment criteria, and younger patients were more likely to lose eligibility if the number of required adequate medication trials increases to three. 4. Broad eligibility criteria tend to differentially exclude Asian patients while more stringent criteria differentially exclude younger and older patients.

Adolescent↗
PubMed1996

Risk factors for herpes simplex virus epithelial keratitis recurring during treatment of stromal keratitis or iridocyclitis. Herpetic Eye Disease Study Group.

AIMS: Possible risk factors were evaluated for herpes simplex virus (HSV) epithelial keratitis in patients with stromal keratouveitis. METHODS: The study population included 260 patients who had active stromal keratitis and/or iridocyclitis without epithelial disease and who were enrolled in one of three clinical trials of the Herpetic Eye Disease Study. Study treatment involved a 10 week course of topical placebo, topical prednisolone phosphate, or topical prednisolone phosphate with oral acyclovir. All groups received topical trifluridine four times daily for 3 weeks then twice daily for another 7 weeks. Patients were examined for HSV epithelial keratitis for 16 weeks. RESULTS: Dendritic or geographic epithelial keratitis occurred in 12 (4.6%) study patients. Adverse effects attributable to trifluridine prophylaxis were acute allergic blepharoconjunctivitis in 10 (3.8%) study patients and corneal epithelial erosions in 11 (4.2%) study patients. No significant difference in the occurrence of HSV epithelial keratitis was found among the study treatment groups: one (2.0%) of 49 topical placebo treated patients, nine (6.5%) of 138 patients treated with topical corticosteroids without acyclovir, and two (2.7%) of 73 patients treated with topical corticosteroids and oral acyclovir. Univariate exponential models suggested that patients with a history of previous HSV epithelial keratitis and non-white patients were more likely to develop HSV epithelial keratitis during treatment of stromal keratouveitis. CONCLUSION: Individuals with prior HSV epithelial keratitis and certain ethnic groups may have a higher rate of recurrent epithelial keratitis during the acute treatment of HSV stromal keratouveitis.

Acyclovir↗
PubMed1996

A competing risks analysis of presenting AIDS diagnoses trends.

The proportions of gay men presenting with various AIDS diagnoses display temporal trends. In particular, the proportion of initial diagnoses reported as Kaposi's sarcoma (KS) has declined over time. Epidemiologists have hypothesized that (a) KS may require a cofactor, whose prevalence has declined over time, or (b) KS may have a shorter incubation period than other presenting diagnoses. We examine whether this latter hypothesis, considered in a competing risks framework, could account for the observed decline in KS. We nonparametrically estimate the relevant cause-specific hazard functions from the doubly-censored data of the San Francisco City Clinic Cohort by maximizing a roughness penalized likelihood using an EM algorithm. These estimates suggest that differences in the underlying cause-specific hazard functions account for a substantial portion of the observed diagnoses trends.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Historical assessment of some specific methods for projecting the AIDS epidemic.

Extrapolation and back-calculation methods for predicting future acquired immunodeficiency syndrome (AIDS) incidence are assessed by examining how they would have performed at various points in the past. The methods use monthly AIDS diagnosis counts through December 1991 for all adults and adolescents in the United States to predict diagnoses 1-3 years into the future. When used on seasonally adjusted data, the average errors in projections by the different methods are smaller than the possible errors due to uncertainty in AIDS counts. This suggests that measuring and improving the completeness of AIDS surveillance may have more potential to improve projections than methodological enhancements.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Survival trees with time-dependent covariates: application to estimating changes in the incubation period of AIDS.

Tree-structured methods for exploratory data analysis have previously been extended to right-censored survival data. We further extend these methods to allow for truncation and time-dependent covariates. We apply the new methods to a data set on incubation times of acquired immunodeficiency syndrome (AIDS), using calendar time as a time-dependent covariate. Contrary to expectation, we find that rates of progression to AIDS appear to be faster after August 1989 than before.

Adult↗
PubMed1995

Effects of stringent criteria on eligibility for clozapine among public mental health clients.

OBJECTIVE: This study estimated rates of eligibility for treatment with clozapine among clients in a public mental health system using criteria with various degrees of restrictiveness. METHODS: A stratified, random cluster sample of 293 clients was selected from among all clients with schizophrenic disorders known to the mental health system of the city and county of San Francisco during 1991. Data on variables associated with eligibility for clozapine were abstracted from clinical records, and eligibility was estimated using broad and stringent criteria. RESULTS: An estimated 42.9 percent of the clients were eligible for clozapine using broad eligibility criteria that included a diagnosis of schizophrenia or schizoaffective disorder, two previous neuroleptic trials of at least 600 mg per day chlorpromazine equivalents for at least four weeks or tardive dyskinesia, Global Assessment of Functioning score less than 61, and no contraindications. Eliminating eligibility due to tardive dyskinesia alone, excluding persons with schizoaffective disorder, requiring six-week medication trials, and requiring three adequate medication trials instead of two resulted in substantial reductions in the rate of eligibility. CONCLUSIONS: Varying interpretations of the criteria for clozapine treatment listed in the medication package insert dramatically affect patients' eligibility for clozapine. Mental health agencies should endeavor to maintain a balance between restricting use of clozapine due to cost and providing it to the full spectrum of patients who might benefit from the medication.

Adolescent↗
PubMed1994

Progression of human immunodeficiency virus type 1 (HIV-1) infection among homosexual men in hepatitis B vaccine trial cohorts in Amsterdam, New York City, and San Francisco, 1978-1991.

The authors evaluated the progression of human immunodeficiency virus type 1 (HIV-1) disease from the date of seroconversion to the development of acquired immunodeficiency syndrome (AIDS) and death among 362 well-documented seroconverters. The participants were homosexual men in hepatitis B vaccine trials in Amsterdam (n = 74), New York City (n = 120), and San Francisco (n = 168). There were significant differences in the proportion of deaths, mean age at seroconversion, and mean age at AIDS diagnosis in the three cohorts, but no significant differences in the reported use of zidovudine and Pneumocystis carinii pneumonia prophylaxis. Overall progression rates did not differ significantly across the cohorts: the median time to the development of AIDS was 122 months, and the median time from the initial AIDS diagnosis to death was 20 months. Multivariate proportional hazards analysis of progression from HIV-1 seroconversion to the development of AIDS found faster progression after June 1989. Multivariate proportional hazards analysis of progression from AIDS to death found younger age at diagnosis, an initial diagnosis of Kaposi's sarcoma, and more recent calendar time to be associated with slower progression. Multivariate proportional hazards analysis of progression from HIV-1 seroconversion to death found older age at seroconversion to be associated with faster progression. The 1987 expansion of the AIDS case definition, improved diagnostic methods, and more conscientious care-seeking behaviors may have resulted in diagnosis of AIDS at an earlier stage of HIV-1 infection, which would shorten the apparent time from seroconversion to progression to AIDS. This would also tend to increase survival after an initial AIDS diagnosis, which was observed in the more recent calendar periods, although such increases could also result from improved treatments and prophylaxis for HIV-1 disease. The time from seroconversion to death, a period not influenced by variations in diagnosing AIDS, lengthened only slightly in recent years.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Interferon-alpha therapy for hepatitis C virus infection after liver transplantation.

The aims of this pilot study were to evaluate the safety and efficacy of interferon-alpha 2b for treatment of hepatitis C virus infection in liver transplant recipients, to monitor changes in hepatitis C virus RNA levels with treatment and to determine pretreatment parameters predictive of a complete response. Eighteen patients with documented hepatitis C virus viremia and histological evidence of hepatitis after liver transplantation received 3 million units of alpha interferon three times weekly for at least 4 mo. Pretreatment serum aminotransferase levels were at least 1.5 times the upper limit of normal and no patient had concomitant hepatitis B virus infection. Response to therapy was defined as normalization of both aspartate and alanine aminotransferase at the end of treatment. Five patients (28%) had a complete response, whereas 13 (72%) had persistent elevation of one or both aminotransferases (nonresponders). At the end of therapy, hepatitis C virus RNA levels were reduced in both responders and nonresponders (p = 0.043 and 0.039, respectively by Wilcoxon signed rank test). After cessation of treatment, aminotransferases remained normal in four of five responders but serum hepatitis C virus RNA levels returned to pretreatment levels in responders and nonresponders. There was no significant change in histological score with therapy. Responders were more likely than nonresponders to have low pretreatment hepatitis C virus RNA levels and low serum bilirubin (p = 0.0004 and 0.0077, respectively). Responders tended to have a prolonged interval between transplantation and initiation of therapy (p = 0.10 by rank logistic regression analysis). Side effects resulted in early cessation of therapy in two patients and dose reduction in six.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine Transaminase↗
PubMed1994

Quantitation of hepatitis C virus RNA in liver transplant recipients.

BACKGROUND/AIMS: Hepatitis C virus (HCV) infection is common in liver transplant recipients, yet the effects of immunosuppression on HCV RNA levels and the relationship of HCV RNA levels to hepatic damage have not been studied. METHODS: To explore these issues, we measured HCV RNA in serum by polymerase chain reaction amplification and branched DNA assay from 100 HCV-infected patients undergoing liver transplantation. RESULTS: Mean posttransplant levels were 16-fold higher than pretransplant values (7,935,000 and 496,000 Eq/mL, respectively; n = 65; P < 0.0001). Patients with high pretransplant levels had higher mean posttransplant levels than those with low pretransplant levels (17,119,000 and 6,504,000 Eq/mL, respectively; P = 0.064). Posttransplant levels were similar in patients with recurrent and acquired infection and were independent of time of sampling. Fifty percent of patients with HCV infection had normal liver biopsy specimens, and there was no strong relationship between level of viremia and degree of hepatic damage. CONCLUSIONS: HCV RNA levels increase markedly following liver transplantation. The frequent finding of viremia in the absence of histological hepatitis suggests that a "carrier state" is common. Absence of allograft damage in some (despite high levels of viral RNA) suggests that in immunosuppressed patients, HCV infection may be tolerated without direct hepatic damage.

Base Sequence↗
PubMed1994

Predicting recidivism after orthotopic liver transplantation for alcoholic liver disease.

With appropriate selection criteria, patients with end-stage alcoholic liver disease who undergo orthotopic liver transplantation have similar graft and patient survivals as patients undergoing transplantation for other causes. However, because of the possibility of recidivism after orthotopic liver transplantation there is still reluctance to transplant alcoholic patients. This study examined the association between pretransplant psychosocial variables and the risk of recidivism after orthotopic liver transplantation. At our institution, 43 patients received orthotopic liver transplantation for the referral diagnosis of alcoholic liver disease from February 1, 1988 to May 1, 1991. This represented 17% of all first transplants (43 of 257) performed during this period. Patients were interviewed before orthotopic liver transplantation by a single psychiatrist and responses to a defined set of questions were entered into a clinical database. All 43 patients diagnosed with alcoholic liver disease and a comparison group of patients transplanted for diagnoses other than alcoholic liver disease received a postoperative questionnaire regarding past and present alcohol use. Patients enrolled in the study all had at least 7 mo of follow-up, with the median follow-up being 21 mo. Eighty-six percent of alcoholic liver disease patients (37 of 43) and 86% of patients in the comparison group (37 of 43) of ALD patients agreed to participate in the study. Nineteen percent of alcoholic liver disease patients (7 of 37) and 24% of patients in the comparison group (9 of 37) admitted to having used alcohol after orthotopic liver transplantation, wtih 8% (3 of 37) and 11% (4 of 37) currently using alcohol, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

HIV seroconversion in intravenous drug users in San Francisco, 1985-1990.

OBJECTIVE: To examine the HIV seroconversion rate, risk factors for seroconversion, and changes in risk behavior over time in intravenous drug users (IVDU) in San Francisco, 1985-1990. DESIGN: Observational study. SETTING: All methadone maintenance and 21-day methadone detoxification programs in San Francisco. PARTICIPANTS: A total of 2351 heterosexual IVDU, of whom 681 were seronegative at first visit and seen at least twice ('repeaters'). MAIN OUTCOME MEASURES: HIV seroconversion rates, risk factors for seroconversion, and changes in behavior. RESULTS: The HIV seroconversion rate in repeaters was 1.9% per person-year (ppy) of follow-up [2.1% in women versus 1.7% in men (not significant); 4% in African Americans versus 1% in whites (P = 0.006); 3.9% ppy in the first third of the study, 1.2% in the second (P = 0.007), and 1.9% in the last (not significant)]. Risk factors for seroconversion were five or more sexual partners per year [hazard ratio (HR) = 2.6; P = 0.02], use of shooting gallery ever (HR = 2.9; P = 0.02), and less than 1 year (lifetime) in methadone maintenance (HR = 2.7; P = 0.02). Self-reported intravenous cocaine use fell from 33 to 15% over 5 years, shooting gallery use fell from 19 to 6%, and the proportion with five or more sexual partners fell from 25 to 10%. Bleach use rose to 75% of needle-sharers. CONCLUSIONS: The 1985-1990 HIV seroconversion rate in IVDU (1.9% ppy) was comparable to that in San Francisco cohorts of homosexual men (1.4% ppy). A decline in HIV seroconversion coincided with changes in risk behavior. Stable attendance of methadone maintenance was highly protective: the seroconversion rate in subjects with 1 year or more in methadone was 12% ppy.

Adult↗
PubMed1994

Hepatitis C in HIV-infected patients with and without AIDS: prevalence and relationship to patient survival.

BACKGROUND: Limited information is available about the prevalence of hepatitis C virus in patients with human immunodeficiency virus in relation to specific risk factors or about the influence of hepatitis C virus coinfection on survival. This retrospective study addressed these questions. METHODS: The study population consisted of 512 predominantly non-intravenous drug-using male homosexuals, 224 of whom had AIDS. Samples positive for hepatitis C virus antibody by second-generation enzyme immunoassay were further tested by means of strip immunoblot assay, and for hepatitis C virus RNA by means of polymerase chain reaction amplification. A randomly selected set of enzyme immunoassay-negative samples was also tested for hepatitis C virus RNA and, if hepatitis C virus RNA positive, by a second-generation recombinant immunoblot assay. RESULTS: The prevalence of hepatitis C virus infection unaccounted for by intravenous drug use or transfusion was 11.7% by enzyme immunoassay, and 87% of sera positive by enzyme immunoassay were also positive by second-generation recombinant immunoblot assay or hepatitis C virus RNA analysis. Hepatitis C virus RNA was detectable in 53% of enzyme immunoassay-positive samples but in only about 1% of enzyme immunoassay-negative samples. Hepatitis C virus coinfection did not influence survival of HIV-infected patients with or without manifestations of AIDS. CONCLUSIONS: Hepatitis C virus infection in nontransfused, non-intravenous drug-using patients with HIV infection is several times more prevalent than in volunteer blood donors, suggesting homosexual transmission of hepatitis C virus. About half of patients seropositive for hepatitis C virus antibody have detectable hepatitis C virus RNA, and serologically occult hepatitis C virus viremia is rare. Hepatitis C virus coinfection does not appear to adversely influence survival.

Acquired Immunodeficiency Syndrome↗