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B A Koblin

Publications and source records attributed to B A Koblin.

30 records · Page 2Linked to original sources
PubMed1996

The feasibility of HIV-1 vaccine efficacy trials among gay/bisexual men in New York City: Project ACHIEVE. AIDS Community Health Initiative Enroute to the Vaccine EFfort.

OBJECTIVE: Candidate populations for HIV-1 vaccine efficacy trials need to be at high risk of infection, adhere to study protocols and be willing to participate. The goal of Project ACHIEVE is to collect baseline data needed in order to prepare for vaccine efficacy trials among gay/bisexual men in New York City. DESIGN AND METHODS: HIV-1 antibody-negative men were recruited into a cohort study with follow-up visits every 3 months (n = 622). Frequency of high-risk behaviors and incidence of HIV-1 seroconversion were measured. RESULTS: Of 544 men reporting having had at least one partner in the previous 3 months who was HIV-1 antibody-positive or of unknown status at baseline, 49% reported receptive anal sex encounters. Thirty-two per cent of these men reported the highest risk behavior, unprotected receptive anal sex. The follow-up rate at 12 months was 81%. The incidence rate of infection was 2.9 per 100 person-years (95% confidence interval: 1.7, 4.9). During follow-up, declines were observed in the proportion of men with an HIV-1 antibody-positive partner and the proportion reporting unprotected receptive or insertive anal sex. HIV-1 infection rates declined from 4.3 per 100 person-years in the first 6 months to 1.6 per 100 person-years by the 12-month visit. CONCLUSIONS: Gay/bisexual men in New York City are still placing themselves at risk of HIV-1 infection and may be a suitable population for future vaccine trials. Continued follow-up is needed to further define the incidence over time, especially for the period after the initial 3 to 6 months when vaccines are most likely to be effective. Immediate prevention efforts need to target this population more effectively.

AIDS Vaccines↗
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↗
PubMed1993

Epidemiology of human immunodeficiency virus type 1 infection among homosexual men participating in hepatitis B vaccine trials in Amsterdam, New York City, and San Francisco, 1978-1990.

Homosexual/bisexual men from Amsterdam, The Netherlands, New York, New York, and San Francisco, California, were entered into trials of the efficacy of hepatitis B vaccine shortly before the acquired immunodeficiency syndrome (AIDS) epidemic was recognized (1978-1980). The authors analyzed data, including serial blood samples tested for antibody to human immunodeficiency virus type 1 (HIV-1) as well as demographic and behavioral information, to characterize the spread of HIV-1 infection within the cohorts. By the end of 1982, the cumulative incidence of HIV-1 infection within the cohorts. By the end of 1982, the cumulative incidence of HIV-1 infection was 7.5% in Amsterdam, 26.8% in New York City, and 42.6% in San Francisco. Covariate analysis showed that differences in sexual activity (number of male sexual partners) and correlates of sexual activity (age and hepatitis B incidence) accounted for the differences in incidence of HIV-1 infection between the New York City and San Francisco cohorts. These covariates did not explain the lower incidence in the Amsterdam cohort. In conclusion, significant differences were found in the spread of HIV-1 in cohorts of homosexual men in Amsterdam, New York City, and San Francisco. These dissimilarities were probably due to a combination of differences in sexual activity at the time the epidemic began and a later introduction of HIV-1 in Amsterdam.

Cohort Studies↗
PubMed1992

Mortality trends in a cohort of homosexual men in New York City, 1978-1988.

Trends in mortality related to infection by human immunodeficiency virus type 1 (HIV-1) and to other causes were examined from 1978 to 1988 in a cohort of 8,906 homosexual men who participated in studies of hepatitis B virus infection in the late 1970s in New York City. HIV-related mortality rates increased from 1 per 10,000 person-years in 1980 to 181 per 10,000 person-years in 1986, followed by a plateau from 1986 to 1988. The standardized mortality ratio among white men in the cohort was 3.7 (95% confidence interval (Cl) 3.4-3.9) as compared with white men from across the United States. Higher HIV-related mortality rates were associated with a higher number of sexual partners, a history of gonorrhea and/or syphilis, and serologic markers of infection with hepatitis B virus. After adjustment for demographics and sexual behaviors, the relative risk of mortality for Hispanic men as compared with white men was 1.5 (95% Cl 1.1-1.9). This study illustrates the large excess in mortality among homosexual men over the last decade, with the excess accounted for by deaths from HIV-related diseases. The recent plateau in mortality may be due to the effect of new treatments and/or the decline in new HIV-1 infections among homosexual men. The excess in HIV-related mortality among Hispanic homosexual men was not explained by differences in demographics and factors associated with the sexual transmission of HIV-1.

Adult↗
PubMed1992

Effect of duration of hepatitis B virus infection on the association between human immunodeficiency virus type-1 and hepatitis B viral replication.

This study examined the effect of duration of hepatitis B virus infection on the association between human immunodeficiency virus type-1 infection and hepatitis B viral replication. Twenty-five chronic HBsAg carriers were studied. Presence of hepatitis B virus DNA and expression of HBeAg were more frequent among 20 chronic HBsAg carriers positive for human immunodeficiency virus type-1 antibody compared with five chronic HBsAg carriers negative for human immunodeficiency virus type-1 antibody, but the associations were not statistically significant. Hepatitis B virus DNA and HBeAg were inversely related to duration of hepatitis B virus infection (p less than 0.001). Stratifying for duration of hepatitis B virus infection, the presence of viral replication was similar among patients negative and positive for antibody to human immunodeficiency virus type-1. Hepatitis B virus DNA levels did not increase with the decline of cellular immunity over time. In conclusion, hepatitis B virus replication among chronic carriers may be a function of duration of hepatitis B virus infection rather than of an effect of human immunodeficiency virus type-1.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Time trends in high-risk injection practices in a multi-site study in Massachusetts: effects of enrollment site and residence.

Time trends in needle sharing and bleach use were examined among needle users enrolled at drug abuse treatment and nontreatment sites in greater Worcester, MA, from 1987 through 1989. Substantial declines in high-risk behavior were found, with different trends at drug treatment versus nontreatment sites. The percentage of individuals sharing needles declined at treatment facilities but not at nontreatment sites. Among those sharing, the proportion using bleach increased at both drug treatment and nontreatment sites. The bleach distribution program in Worcester appears to be associated with increased bleach use among residents. Bleach use was associated with residence in Worcester, after controlling for age, gender, race, enrollment site, time period, and frequency of sharing. Risk reduction in the subpopulation of needle users entering treatment was greater than that among those not in treatment. As avoidance of sharing is likely to be more effective than bleaching for the prevention of human immunodeficiency virus (HIV) transmission, the subpopulation not in treatment should be targeted for prevention programs.

Adolescent↗
PubMed1991

Differences in antibody response to whole-cell pertussis vaccines.

It has been assumed that whole-cell pertussis vaccines (WCVs) commercially distributed in the United States are of comparable immunogenicity, as all must comply with established standards for licensure. However, we have recently noted significant differences in antibody responses between groups of infants receiving the two WCVs commercially available in the United States. In separate studies performed concurrently under similar protocols at Vanderbilt and Johns Hopkins universities, infants were randomized to receive either an acellular pertussis vaccine or WCV. The acellular pertussis vaccine used at the two sites was identical, but the WCVs were from different manufacturers. Antibody responses to acellular pertussis vaccine did not differ between the two studies; responses to WCV differed dramatically, with infants receiving the Lederle WCV producing a 46-fold increase in antibody to pertussis toxin, compared with a 2.4-fold increase for infants receiving the Connaught WCV (P = .00003). Evaluation of other comparative data sets that were available provided further support for the conclusion that the two commercially available WCVs consistently differed in their ability to induce antibody to pertussis toxin. These findings have important implications for the design and interpretation of clinical trials comparing acellular and WCV products.

Adhesins, Bacterial↗
PubMed1990

Racial/ethnic differences in HIV-1 seroprevalence and risky behaviors among intravenous drug users in a multisite study.

Differences in human immunodeficiency virus type 1 (HIV-1) seroprevalence and patterns of drug-use and sexual behaviors were examined among Hispanic, black, and white intravenous drug users recruited at multiple sites in Worcester, Massachusetts. A total of 1,092 (786 males, 306 females) intravenous drug users were interviewed, and HIV-1 antibody test results were available for 874 (80.0%). After adjustment for demographic differences, black males were significantly less likely to report risky drug-use behaviors (ever sharing needles and recently visiting shooting galleries) compared with white males. In contrast, Hispanic males were significantly more likely to report recent risky drug-use behaviors (sharing needles in New York City, daily needle-sharing, and visiting shooting galleries). Both groups were less likely to report risky sexual behaviors compared with whites. The odds ratios for HIV-1 seropositivity remained significantly greater than 1 for Hispanics compared with whites (odds ratio = 4.5) and maintained marginal significance for blacks compared with whites (odds ratio = 2.1) when adjusted for risky behaviors and demographic variables. The different patterns of drug-use and sexual behaviors by race/ethnicity indicate the need for interventions targeted to specific populations.

AIDS Serodiagnosis↗
PubMed1989

Immunity to diphtheria and tetanus in inner-city women of childbearing age.

This study was conducted to determine immunity to diphtheria and tetanus in 232 inner-city women experiencing a recent birth. Forty-three (18.5 percent) of the women had levels of diphtheria antitoxin below the protective level (less than 0.01 unit/ml), whereas only 10 (4.3 percent) had insufficient levels of tetanus antitoxin. The percent of women susceptible increased with age, with 33 percent and 25 percent of women over the age of 30 years susceptible to diphtheria and tetanus, respectively.

Adolescent↗
PubMed1988

Response of preterm infants to diphtheria-tetanus-pertussis vaccine.

The American Academy of Pediatrics recommendation that immunization of preterm infants with diphtheria-tetanus-pertussis (DTP) vaccine should begin at 2 months after birth, regardless of gestational age, is based on limited data. A prospective study was conducted to determine the immunogenicity and safety of DTP vaccine in preterm infants. One hundred ten preterm and 146 full term infants received doses of DTP at 2, 4 and 6 months after birth. Adjusted analysis of the antibody responses indicated that after three doses mean titers among preterm infants to each vaccine component were comparable to those of full term infants. Adjusted analysis of the incidence of adverse events indicated that the risk of adverse events in preterm infants was not significantly higher than that in full term infants. DTP vaccine is immunogenic and safe in preterm infants when the series is initiated at 2 months after birth, and this study supports the current recommendation of the American Academy of Pediatrics.

Antibody Formation↗
PubMed1982

Lysozyme activity in cystic fibrosis.

The activity of lysozyme in saliva and serum was determined in 51 patients with cystic fibrosis. Measurements were made on two occasions at least 1 month apart and compared to those of 25 normal healthy individuals of the same ages, sex, and race. The mean serum lysozyme activity of normal individuals was 5.8 micrograms/ml (S.E. = 0.4), whereas that of cystic fibrosis patients was 10.8 micrograms/ml (S.E. = 0.5). The difference is significant (P less than 0.05). Initial mean values compared to those of repeated samples from the cystic fibrosis group were similar, whereas individual fluctuations occurred between test periods. The mean lysozyme activity of the saliva sample of normal individuals was 63.5 micrograms/ml (S.E. = 9.3) and the mean value from cystic fibrosis patients was 82.7 (S.E. = 6.9). This difference was not significant (P greater than 0.1). Mean values from specimens obtained a month or longer after the initial saliva samples were similar for the two episodes. There was no correlation between the serum and salivary values and the age, sex or race of the subjects, the Shwachman-Kulczycki scores, colonization with Pseudomonas aeruginosa, Staphylococcus aureus or Haemophilus influenzae or absolute white blood cell counts. In vitro studies failed to demonstrate bactericidal activity for mucoid and nonmucoid strains of P. aeruginosa or for S. aureus. Elevated lysozyme activity in cystic fibrosis may be related to either an increased granulocyte turnover because of chronic bacterial infection of the respiratory tract or to a basic defect in the lysosomal membrane allowing an increased release of the enzyme, or a combination of both.

Adolescent↗