Biomedical subjects

E Vittinghoff

Publications and source records attributed to E Vittinghoff.

66 records · Page 4Linked to original sources

PubMed1994

Mycobacterium avium complex in the respiratory or gastrointestinal tract and the risk of M. avium complex bacteremia in patients with human immunodeficiency virus infection.

Mycobacterium avium complex (MAC) is frequently isolated from the respiratory or gastrointestinal tract of patients with advanced human immunodeficiency virus (HIV) infection. Whether they are at increased risk of MAC bacteremia and whether culture of respiratory tract or stool specimens is useful for predicting bacteremia are unclear. HIV-infected patients with < or = 50 CD4+ cells/microL were prospectively studied. The risk of MAC bacteremia was approximately 60% within 1 year for patients with MAC in either the respiratory or gastrointestinal tract and was greater than for those without MAC in these sites (relative hazards for respiratory and gastrointestinal tract, 2.3 and 6.0; 95% confidence intervals, 1.1-4.6 and 2.5-14.6, respectively). Both respiratory tract specimen and stool culture had poor sensitivities (22% and 20%, respectively) but good positive predictive values (approximately 60%) for bacteremia. Symptomatic HIV-infected patients with MAC in the respiratory or gastrointestinal tract are at a substantial risk for developing MAC bacteremia; culture of these sites has limited usefulness as a screening test.

Adult↗

PubMed1994

The impact of Mycobacterium avium complex bacteremia and its treatment on survival of AIDS patients--a prospective study.

It is currently recommended that patients with AIDS and Mycobacterium avium complex (MAC) bacteremia receive antimycobacterial treatment. However, no study has prospectively evaluated the impact of this infection and its treatment on survival. This study prospectively followed a cohort of 367 AIDS patients with < or = 50 CD4+ cells/microL and found that MAC bacteremia was independently associated with an increased risk of death (relative hazard [RH] = 1.8, 95% confidence interval [CI] = 1.3-2.4, P < .001). Patients with MAC bacteremia who were treated had a longer median survival than those who were not (263 vs. 139 days, P < .001); treatment was independently associated with a lower risk of death (RH = 0.45, 95% CI = 0.23-0.89, P < .001). However, 23% of patients with bacteremia died within 28 days of that diagnosis; few were treated. MAC bacteremia contributes to the death of patients with AIDS, and treatment increases survival. However, many patients will not survive long enough to receive treatment. These results underscore the importance of early diagnosis and chemoprophylaxis for MAC bacteremia.

AIDS-Related Opportunistic Infections↗

PubMed1993

Aetiology of AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗

PubMed1993

Does drug use cause AIDS?

A hypothesis identifying substance abuse as a main cause of AIDS has naturally excited much publicity. But such claims have no basis in fact.

Acquired Immunodeficiency Syndrome↗

PubMed1993

The characterization of non-progressors: long-term HIV-1 infection with stable CD4+ T-cell levels.

OBJECTIVE: To identify and characterize individuals with long-term HIV-1 infection who have experienced little or no progressive CD4+ T-cell loss during follow-up. PATIENTS AND METHODS: The rate of CD4+ T-cell loss (CD4 slope) was determined for each of the 290 participants in the San Francisco Men's Health Study who were seropositive at study entry in 1984. The study population was stratified, by CD4 slope, into 10 groups of 29 individuals and each group was characterized using a variety of cross-sectional and longitudinal laboratory measurements. RESULTS: Approximately 10% of the HIV-1-infected men experienced no net CD4+ T-cell loss during 78 months of follow-up. Compared with all other seropositive subjects, these 'non-progressors' were the extreme cases in a relatively continuous distribution of CD4 slopes, rather than a discrete subpopulation. Although they had no net cell loss, their mean CD4+ cell count was approximately 400 x 10(6)/l lower and their mean CD8+ cell count approximately 250 x 10(6)/l higher than seronegative subjects, suggesting early changes followed by stabilization. The CD4 slope was associated with the levels of beta 2-microglobulin, neopterin, p24 antibody, erythrocyte sedimentation rate, viral burden, and the proportion of HIV-1 isolates with tropism for the MT-2 T-cell line. Multivariate cluster analysis of these laboratory markers did not distinguish the non-progressors as a distinct subgroup. CONCLUSIONS: These findings support both a biphasic natural history and the suggestion that the broad range in HIV disease progression rates may be the result of several independent factors interacting in a variety of combinations. Recent changes in laboratory markers, known to predict both CD4+ cell loss and AIDS, suggest that non-progressors are undergoing slow HIV disease progression.

Acquired Immunodeficiency Syndrome↗

PubMed1993

Use of T lymphocyte subset analysis in the case definition for AIDS.

Infection with HIV-1 and < 200 CD4+ lymphocytes/mm3 has been proposed as an AIDS-defining condition. We have evaluated the effects of using this and other T-cell subset measurements, in the diagnosis of AIDS in two cohorts of homosexual/bisexual men in San Francisco. Among 762 HIV-1 infected men, 200 CD4+ lymphocytes/mm3 corresponded to 13 percent CD4+ lymphocytes and a CD4+/CD8+ ratio of 0.23. If these AIDS-defining criteria had been implemented in mid-1991, the number of living AIDS cases would have increased by 106 (212%), 133 (266%), and 136 (272%), respectively. When these criteria were first met, either before or in the absence of a clinical AIDS diagnosis, about half of the subjects were asymptomatic and the median clinically AIDS-free interval was approximately 2 years. Using two consecutive tests or pair-wise combinations of criteria reduced the number of cases identified by testing error or transient biological variation, but the number of living AIDS cases would still be increased more than twofold. Finally, any AIDS case definition using a specific T-cell subset value will be compromised by the inherent variability in these measurements and the substantial overlap in the results for those with and without clinical manifestations of HIV infection.

Acquired Immunodeficiency Syndrome↗

PubMed1991

Safety and immunogenicity of oligosaccharide conjugate Haemophilus influenzae type b (HbOC) vaccine in infancy. The Northern California Kaiser Permanente Vaccine Study Center Pediatrics Group.

The safety and immunogenicity of the HbOC conjugate vaccine have been evaluated in a study population of 61,080 children in the Kaiser Permanente Medical Care Program of Northern California. Half of the population served as controls. The vaccine was given as part of a three-dose regimen in the first year of life with the first dose given between 6 weeks and 6 months of age, a minimum interval of 1 month between doses and with the third dose given by 1 year of age. The vaccine was highly immunogenic with 97% of infants developing 1 microgram/ml or more of anti-polyribosyl phosphate antibody as measured by Farr assay 1 month after completion of the three-dose series and with 71% maintaining this concentration until a booster dose was given at approximately 18 months of age. There were three cases of Haemophilus influenzae type b disease after the first dose of vaccine and two of these children died. However, there was no statistically significant difference between either the incidence of H. influenzae type b disease or the mortality rate in infants after one dose of HbOC vaccine when compared with H. influenzae type b disease incidence and mortality in unvaccinated children of the same age. The rate of sudden infant death syndrome following HbOC vaccine was lower than that observed within the Kaiser Permanente Medical Care Program as a whole or in the three counties in which sudden infant death syndrome surveillance was tabulated. Immediate local and systemic reactions were evaluated by telephone interviews of 6887 infants within 72 hours of vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Bacterial↗

PubMed1991

Efficacy in infancy of oligosaccharide conjugate Haemophilus influenzae type b (HbOC) vaccine in a United States population of 61,080 children. The Northern California Kaiser Permanente Vaccine Study Center Pediatrics Group.

The efficacy of the HbOC conjugate Haemophilus influenzae type b vaccine was evaluated in a study population of 61,080 infants in the Northern California Kaiser Permanente Medical Care Program. Between February, 1988, and June, 1990, the HbOC vaccine was given as part of a three-dose series at 2, 4, and 6 months of age to 20,800 infants. The study population included children with a well-care visit at a study center during the first 6 months of life. There were 25 cases of Haemophilus influenzae type b disease in the study population: 22 in unvaccinated children and 3 in children who received only one dose of HbOC vaccine. The efficacy of the full three-dose series was evaluated by several methods: a primary analysis comparing fully vaccinated children with unvaccinated children from 7 to 18 months of age; a stratified exact analysis adjusted for age and seasonality; and a case-control analysis which further adjusted for known risk factors. The efficacy of three doses of vaccine was 100% with the lower bound of the 95% confidence interval for the three analyses at 68, 71, and 64%, respectively. There were no cases of disease resulting from two doses of HbOC vaccine yielding an estimate of 100% efficacy (95% confidence interval, 47 to 100) for two doses of HbOC vaccine. However, for children who had received only one dose of HbOC vaccine, vaccine efficacy was estimated to be 26% and the possibility that one dose of HbOC vaccine had no efficacy could not be excluded.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Proteins↗

PubMedDate not supplied

The relation of smoking to waist-to-hip ratio and diabetes mellitus among elderly women.

BACKGROUND: Smoking is associated with lower body weight, but an increased risk of diabetes in some studies. Because smoking may increase waist-to-hip ratio (WHR), a risk factor for diabetes, we postulated that the relation between smoking and diabetes may be mediated in part by smoking-associated differences in body fat distribution. METHODS: We conducted a cross-sectional analysis of baseline data from 9,435 elderly nonblack women enrolled in the Study of Osteoporotic Fractures. Data were collected by Self-report and physical examination. Linear and logistic models were used to determine the relation of smoking to WHR and prevalence of self-reported diabetes. RESULTS: Current and past smokers had greater WHRs compared with never smokers. In multivariate models that adjusted for body mass index, the prevalence of diabetes was lower among smokers of < or = 10 cigarettes/day [odds ratio (OR) = 0.57, 95% confidence interval (CI) 0.31-1.03] and higher among smokers of > 10 cigarettes/day (OR = 1.38, 95% CI 0.99-1.92) compared with never smokers. The relation of smoking > 10 cigarettes/day to prevalence of diabetes was slightly attenuated after further adjustment for WHR. CONCLUSIONS: Smoking-associated differences in WHR may mediate, at least in part, the prevalence of diabetes among smokers of > 10 cigarettes/day. The decreased prevalence of diabetes that we observed among smokers of < or = 10 cigarettes/day was not explained by differences in obesity and requires confirmation.

Aged↗

PubMedDate not supplied

Management of pelvic inflammatory disease by primary care physicians. A comparison with Centers for Disease Control and Prevention guidelines.

BACKGROUND: The Centers for Disease Control and Prevention published recommendations for clinicians on the management of pelvic inflammatory disease, but it is unknown if providers are aware of the guidelines or follow them. GOAL: To compare pelvic inflammatory disease screening, diagnosis, treatment, and reporting practices among primary care physicians with the Centers for Disease Control and Prevention guidelines for pelvic inflammatory disease. STUDY DESIGN: A weighted random sample of California primary care physicians surveyed in November 1992 and January 1993. RESULTS: Of the 1,165 physicians surveyed, 553 (48%) returned completed questionnaires. Among respondents, 302 (55%) reported having treated a case of pelvic inflammatory disease during the last 12 months, and of these, 52% answered that they were unsure of or do not follow the Centers for Disease Control and Prevention guidelines for pelvic inflammatory disease. Pediatricians and those with more years since residency were less likely to deviate from the Centers for Disease Control and Prevention guidelines for pelvic inflammatory disease, and family practitioners were more likely to deviate from the guidelines. CONCLUSIONS: Pelvic inflammatory disease is commonly encountered by primary care physicians in California. Training and experience were important predictors of compliance with the Centers for Disease Control and Prevention recommendations; however, substantial divergence from the guidelines occurs.

Adolescent↗

PubMedDate not supplied

Antibiotics in chronic obstructive pulmonary disease exacerbations. A meta-analysis.

OBJECTIVE: A meta-analysis of randomized trials was performed to estimate the effectiveness of antibiotics in treating exacerbations of chronic obstructive pulmonary disease (COPD). DATA SOURCES: English-language studies published from 1955 through 1994 were retrieved using MEDLINE, Index Medicus, bibliographies, and consultation with experts. MEDLINE search terms included "COPD," "chronic bronchitis," and "antibiotic(s)." STUDY SELECTION: Only randomized trials that enrolled patients having an exacerbation of COPD, used an antibiotic in the treatment group and placebo in the control group, and provided sufficient data to calculate an effect size were included in the meta-analysis. DATA EXTRACTION: Descriptive and outcome data from each study were independently in the meta-analysis. DATA SYNTHESIS: Overall summary effect size of the nine trials satisfying all inclusion criteria was 0.22 (95% confidence interval [CI], 0.10 to 0.34), indicating a small benefit in the antibiotic-treated group. Similar analysis of the six studies that provided data on peak expiratory flow rate changes revealed a summary effect size of 0.19 (95% CI, 0.03 to 0.35) and a summary change in peak expiratory flow rate of 10.75 L/min (95% CI, 4.96 to 16.54 L/min) in favor of the antibiotic-treated group. Sensitivity analyses did not significantly affect these results. CONCLUSIONS: These analyses suggest a small but statistically significant improvement due to antibiotic therapy in patients with exacerbations of COPD. This antibiotic-associated improvement may be clinically significant, especially in patients with low baseline flow rates.

Anti-Bacterial Agents↗

PubMedDate not supplied

Adherence to National Cholesterol Education Program Treatment goals in postmenopausal women with heart disease. The Heart and Estrogen/Progestin Replacement Study (HERS). The HERS Research Group.

OBJECTIVES: To determine the proportion of volunteer women with established heart disease who have low-density lipoprotein cholesterol (LDL-C) levels at or below the National Cholesterol Education Program Adult Treatment Panel goals and to determine what factors are associated with levels above goal or not receiving lipid-lowering medication when indicated. DESIGN: Cross-sectional measurement of lipids and lipoproteins, blood pressure, height, weight, and other demographic and cardiovascular risk factors in 2763 postmenopausal women with heart disease. SETTING: At 18 centers throughout the United States, participants were recruited by means of lists of women with coronary heart disease from coronary units and catheterization laboratories, direct mail to age-eligible women, and advertisements. PATIENTS: Mean age of the cohort was 66.7 years (range, 44-79 years) and the distribution by race/ethnicity was 88.7% white, 7.9% African American, 2.0% Hispanic/Latina, 0.8% Asian/Pacific Islander, and 0.7% other. INTERVENTION: We report cross-sectional analysis of the cohort at baseline. OUTCOME MEASURES: We measured the frequency of achieving 1988 and 1993 Adult Treatment Panel treatment goals, and of being on a regimen of lipid-lowering medication. RESULTS: Although 47% of participants were taking a lipid-lowering medication, 63% did not meet the 1988 treatment goal of LDL-C level less than 3.4 mmol/L (130 mg/dL) and 91% did not meet the 1993 goal of LDL-C level less than 2.6 mmol/L (100 mg/dL). Factors independently associated with achieving the earlier goal were use of lipid-lowering medication, marital status, education, body mass index, exercise, hypertension, diabetes, gallbladder disease, and first diagnosis of coronary heart disease after 1990. Failure to use lipid-lowering medication was associated with age, being African American, marital status, body mass index, lack of exercise, alcohol consumption, current smoking, and first diagnosis of coronary heart disease before 1985. CONCLUSION: The majority of women enrolled in the trial had LDL-C levels that significantly exceeded the treatment goals set by the 1988 and 1993 Adult Treatment Panel guidelines. Better implementation of these guidelines among women with coronary disease would be highly desirable.

Aged↗