Search PubMed⌕ Search

Biomedical subjects

R J Biggar

Publications and source records attributed to R J Biggar.

At least 19 recordsLinked to original sources
PubMed1992

Risk of suicide among persons with AIDS. A national assessment.

OBJECTIVE: We sought to describe the rate, risk, trends, methods, and distribution of suicide among persons with the acquired immunodeficiency syndrome (AIDS) in the United States. DESIGN: We used National Center for Health Statistics multiple-cause mortality data from 1987 through 1989 to identify suicides among persons with AIDS (PWAs) and public-access AIDS surveillance data to determine person-years of observation of PWAs. PATIENTS: Residents of the United States with death certificates indicating suicide. MAIN OUTCOME MEASURE: Death certificates indicating both AIDS and suicide. RESULTS: In 1987 through 1989, a total of 165 suicides among PWAs occurred in 45 states and the District of Columbia. All but one case were male. Among males the rate was 165 per 100,000 person-years of observation, 7.4-fold higher than among demographically similar men in the general population. Self-poisoning with drugs was both the most common method (35%) and the method with the highest standardized mortality ratio (35). Suicide risk for PWAs decreased significantly (P < .05) from 1987 to 1989. CONCLUSION: Persons with AIDS have an increased risk of suicide, and assessment of such risk should be a standard practice in their care. These assessments should be carefully considered when potentially lethal medications are prescribed. The declining trend in suicide rates between 1987 and 1989 is encouraging; possible causes include emerging therapies for human immunodeficiency virus/AIDS, better psychiatric care for these patients, and lessened social stigma against PWAs.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Second primary cancers following anal and cervical carcinoma: evidence of shared etiologic factors.

The authors examined the incidence of second primary cancers occurring after cervical and anal cancer. Data from the Connecticut Tumor Registry for 1935-1988 and eight other US tumor registries for 1973-1988 were used. Women with primary invasive cervical cancer had a relative risk of 4.6 (95% confidence interval (CI) 2.4-8.1) for subsequent invasive anal cancer. Increased relative risks after cervical cancer were also found for cancers of the oral cavity (relative risk (RR) = 2.2), stomach (RR = 1.5), rectum (RR = 1.4), larynx (RR = 3.4), lung (RR = 3.0), vagina (RR = 5.6), bladder (RR = 2.7), for kidney (RR = 1.9); decreased relative risks were noted for melanoma (RR = 0.5) and breast cancer (RR = 0.8). Patients with a primary diagnosis of anal cancer had relative risks for subsequent invasive and in situ cervical cancer of 1.3 (95% CI 0.2-4.5) and 3.4 (95% CI 0.9-8.8), respectively. Anal cancer was also associated with increased relative risks of subsequent lung (RR = 2.5) and prostate (RR = 1.8) cancers, whereas the relative risk of uterine cancer was 0.2 (95% CI 0.0-0.9). These findings support other evidence for common factors, such as human papillomavirus infection and cigarette smoking, in the etiology of cervical and anal cancer.

Anus Neoplasms↗
PubMed1992

Immunologic markers of progression to acquired immunodeficiency syndrome are time-dependent and illness-specific.

Since prevalent cohorts may be biased by the duration of human immunodeficiency virus (HIV) infection (onset bias), it is useful to assess the potential predictive value of markers in incident cohorts of HIV-positive subjects for whom the date of seroconversion is known or can reliably be estimated. Of 131 homosexual men with HIV-1 seroconversion from New York City and Washington, DC, who were evaluated annually beginning in 1982, 60 developed acquired immunodeficiency syndrome (AIDS) by the end of 1989. The prognostic significance of immunologic markers (proportion of CD4+ T-lymphocytes, neopterin, beta 2-microglobulin, serum interferon, and anti-p24 antibody) and of a virologic marker (HIV p24 antigen) was determined using measurements made at defined time intervals after the known or estimated date of HIV seroconversion. When measurements made 3 years after seroconversion were used, all markers except anti-p24 antibody were found to be significant estimators of AIDS risk in univariate analyses. In multivariate Cox regression modeling, the maximum information was obtained by including neopterin, interferon, and the CD4+ T-lymphocyte proportion. The predictive value of markers after HIV seroconversion could change considerably from one interval to another. Elevated levels of beta 2-microglobulin and neopterin significantly predicted the development of Kaposi's sarcoma. These two markers were highly correlated (r = 0.74). The authors conclude that immunologic markers can be important for an HIV staging system for estimating prognosis and facilitating early therapeutic intervention in HIV-positive patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Interactions between persons at risk for AIDS and the general population in Denmark.

A nationwide study of sexual behavior was undertaken among 4,680 randomly selected Danes aged 18-59 years. The median number of sexual partners (lifetime) was highest for men aged 30-34 years (eight partners) and for women aged 25-29 years (seven partners). After adjustment for age and sex, having had greater than or equal to 5 sexual partners in the past year was strongly associated with living in larger cities, intravenous drug use, and having sex with a prostitute, a bisexual man, an intravenous drug user, or a resident of sub-Saharan Africa. The frequency of ever having had anal intercourse was highest among women aged 20-34 years (range, 27%-36%) and was independently associated only with increasing number of sexual partners (lifetime). Overall, 2.7% of men reported any homosexual experience, among whom most (88%) had also had heterosexual intercourse. Prostitute contact (ever) was reported by 13% of all men and was associated with a high educational level, a history of travel, a greater number of sexual partners, and intravenous drug use. Overall, sexual contact with someone considered at high risk of human immunodeficiency virus (HIV) infection (a homosexual/bisexual man, intravenous drug user, prostitute, or sub-Saharan African resident) was reported by 15.9% of men and 4.8% of women. Among active blood donors (past year), 12.5% of men and 4.0% of women had engaged in potentially risky behavior. HIV testing was deliberately sought more often by respondents exposed to someone at increased risk of HIV infection (10.6%) than by those unexposed (6.5%, p less than 0.01). Exposure to persons at risk of HIV infection is considerable in Denmark. The majority of persons who have had potential exposure to HIV have not yet been tested for HIV.

AIDS Serodiagnosis↗
PubMed1992

Endemic human T cell lymphotropic virus type II infection among isolated Brazilian Amerindians.

Evidence for human T cell lymphotropic viruses (HTLV) was sought in sera and cells collected from adults in 13 isolated South and Central American Indian tribes. Serologic tests identified frequent HTLV-II-like reactivity among the Cayapo and Kraho tribes, who live 330 km apart in Central Brazil. Polymerase chain reaction analyses of viral DNA in cell pellet and plasma fractions confirmed the virus as HTLV-II. Both tribes speak Gé and, at the time of blood collection (1974), subsisted as hunter/gatherers and slash and burn agriculturalists. Further testing of plasma from Cayapo and Kraho of all ages revealed overall HTLV-II prevalence rates of 33.3% and 12.2%, respectively, with increasing prevalence associated with age and female gender. These data reveal for the first time a high prevalence of HTLV-II infection in remote South American Indians with little contact with non-Indians. Thus, HTLV-II is postulated to be an ancient human virus in the New World.

Adult↗
PubMed1992

The epidemiology of acquired immunodeficiency syndrome-related lymphomas.

Approximately 3% of acquired immunodeficiency syndrome cases present with non-Hodgkin's lymphoma. By 6 to 8 years after human immunodeficiency virus infection, lymphoma risk is elevated 100-fold, and the risk approaches 1% per year following acquired immunodeficiency syndrome diagnosis. The proportions presenting as lymphoma differ by age, sex, and race, with relative rates being higher in older persons, males, and whites. The differences are similar in magnitude and direction to those seen in non-human immunodeficiency virus-infected persons and account for the variation by risk group. The relative risk of high-grade lymphoma is greatest, but significant increases are also seen for some intermediate-grade tumors. At diagnosis, persons with Burkitt's lymphoma, more common in children, have significantly higher average CD4 counts than those with immunoblastic tumors. Human immunodeficiency virus-associated lymphoma risk is probably related to dysregulation of the immune system leading to uncontrolled proliferation of transformed cell clones and subsequent genetic accidents. Environmental factors are unlikely to be important. By 1994, 10% of all lymphomas will be human immunodeficiency virus related, but this proportion will increase in the future. New approaches to the therapy of lymphoma are needed for this tumor, which we can neither prevent nor adequately treat.

Adolescent↗
PubMed1992

Responses to anonymous questionnaires concerning sexual behavior: a method to examine potential biases.

OBJECTIVES: Low response rates to voluntary surveys raise questions about how representative the responses are. We compared the behavior and attitudes of responders, willing and reluctant, and nonresponders to anonymous questionnaires about behaviors that might expose participants to the human immunodeficiency virus (HIV). METHODS: Questionnaires were sent to 1080 Danish adults 18 through 59 years including explicit questions about sexual acts and illegal drug use. Identical questionnaires were sent to 3600 other Danes, similarly chosen; packets sent to these persons included cards to be returned separately informing us that they had responded. Questionnaires were sent twice more to nonresponders, who, if they then responded, were considered reluctant responders. One hundred nonresponders were telephoned and asked why they had refused to respond. RESULTS: Enclosing return cards did not affect initial response rate, but prompting boosted replies from 52% to 73%. However, behaviors were generally similar among initial and reluctant responders. One third of nonresponders agreed to respond if we wished (total potential response: 82%). In general, the reasons for nonresponse did not suggest that the life-styles of nonresponders placed them at risk for HIV infection. CONCLUSIONS: This method provides a simple, inexpensive approach to improving response rates and learning about the biases of reluctant responders and nonresponders.

Acquired Immunodeficiency Syndrome↗
PubMed1991

High risk of HIV-1 infection for first-born twins. The International Registry of HIV-exposed Twins.

To examine the epidemiology and natural history of mother-to-infant transmission of human immunodeficiency virus type 1 (HIV-1), especially genetic and intrapartum exposure factors, we obtained data on twins and triplets born to women infected with the virus. 40 investigators in nine countries contributed demographic, clinical, and epidemiological data on 100 sets of twins and 1 set of triplets. Among the 66 evaluable sets, HIV-1 infection was more common in first-born than in second-born twins (p = 0.004). In 22 sets, only one twin was infected (18 first-born, 4 second-born). 50% of first-born twins delivered vaginally and 38% of first-born twins delivered by caesarean were infected, compared with 19% of second-born twins delivered by either route. HIV-1 infection status tended to be concordant in more monozygotic (14 of 17 sets) than dizygotic (26 of 43) sets, but the frequency and clinical signs of HIV-1-related disease were similar in only 3 of the 10 sets with both children infected. These findings suggest that some infants may be infected in utero before labour but that a substantial proportion of HIV-1 transmission occurs as the first twin encounters the cervix and birth canal. Such measures as cleansing of the birth canal and caesarean delivery before membrane rupture might reduce the risk of transmission for infants born to HIV-1-infected women and should be the subjects of controlled clinical trials. Caesarean section should not be regarded as a wholly preventive measure, however, since substantial proportions of both first-born and second-born twins delivered in this way were infected.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Preventing AIDS now.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Projections of the incidence of non-Hodgkin's lymphoma related to acquired immunodeficiency syndrome.

Advances in antiretroviral therapy and treatment or prophylaxis against opportunistic infection have resulted in prolongation of the survival of patients with acquired immunodeficiency syndrome (AIDS). Previous research has demonstrated an association between AIDS and risk of non-Hodgkin's lymphoma (NHL). In addition to the approximately 3% of individuals found to have NHL at the time of AIDS onset, others continue to develop NHL following AIDS diagnosis. Data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute demonstrated a sharply increasing incidence of NHL among men in the age range 20-49 years since 1983 in the United States. Based on new data on the risk of NHL following AIDS diagnosis, on estimates of improved survival following AIDS diagnosis, and on projections of future AIDS incidence, we considered four sets of assumptions and estimated the number of AIDS-related NHL cases in 1992 to be between 2900 and 9800. Three of these projections were higher than the estimate of 4700 cases obtained by linear extrapolation of SEER incidence trends. These projections of AIDS-related NHL incidence suggest that between 8% and 27% of all NHL cases that occur in the United States in 1992 will arise as a consequence of infection with the human immunodeficiency virus (HIV), imposing a substantial health care burden. More research into the pathogenesis of lymphoma and new approaches to antiretroviral and antilymphoma therapy will be necessary to prevent and treat this formidable complication of infection with HIV.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Increasing incidence of cancers associated with the human immunodeficiency virus epidemic.

We examined data from San Francisco and other areas participating in the Surveillance, Epidemiology, and End Results (SEER) Program to determine the effect of the human immunodeficiency virus (HIV) epidemic on cancer incidence between 1973 and 1987. In this period, non-Hodgkin's lymphoma incidence has increased over 10-fold and Kaposi's sarcoma incidence has increased over 5000-fold in single San Francisco men 20 to 49 years of age. Increases in non-Hodgkin's lymphoma have been restricted to high-grade and diffuse large-cell (intermediate-grade) histological types. With the exceptions of non-Hodgkin's lymphoma and Kaposi's sarcoma, no other tumor has significantly increased in incidence. During 1987, we estimate that HIV-seropositive men in San Francisco had a 0.47% risk of developing non-Hodgkin's lymphoma and a 1.6% risk of developing Kaposi's sarcoma. The relative risks for non-Hodgkin's lymphoma and Kaposi's sarcoma associated with HIV infection were 104 and 40,000, respectively. For 1987, HIV was associated with 14% of all reported cancers (except non-melanoma skin cancer) in men aged 20 to 49. We expect that 1,890 to 2,730 excess cases of non-Hodgkin's lymphoma and 6,490 to 8,320 excess cases of Kaposi's sarcoma will occur in the United States in 1990.

Adult↗
PubMed1991

Backcalculation of the number with human immunodeficiency virus infection in the United States.

The method of backcalculation was applied to national surveillance data on the acquired immunodeficiency syndrome (AIDS) in order to estimate the cumulative number of adults with human immunodeficiency virus type 1 (HIV-1) infection as of January 1, 1985 and July 1, 1987. A "plausible range" of estimates was constructed which reflected both uncertainty about the AIDS incubation distribution and random variation from selection and fitting of flexible models of the HIV-1 infection curve. The authors estimated that, as of 1985, 411,000 to 756,000 persons were infected. The infected population included 266,000 to 492,000 homosexual men, 69,000 to 136,000 intravenous drug users, 24,000 to 49,000 homosexual intravenous drug users, and 11,000 to 26,000 persons infected through heterosexual contact. The estimated prevalence of infection among persons aged 15-55 years was 0.31% in whites, 0.78% in Hispanics, and 0.81% in blacks. An estimated 32,000 to 66,000 women were infected. Compared with white women aged 15-55 years, the prevalence of infection was 5.3-fold higher in Hispanic women and 10.2-fold higher in black women. Plausible estimates for the total number infected by July 1987 ranged from 707,000 to 1,376,000, with the most likely estimate equal to 992,000. Backcalculation provides an assessment of the magnitude of the HIV-1 epidemic that is independent of estimates based on prevalence surveys in special populations. The estimates obtained from both methods are consistent and emphasize the need for vigorous programs to prevent the spread of HIV-1, especially in minority communities.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Kaposi's sarcoma and non-Hodgkin's lymphoma in European AIDS cases. No excess risk of Kaposi's sarcoma in Mediterranean countries.

Prior to the AIDS epidemic, Kaposi's sarcoma (non-AIDS-KS) in Europe was mainly a disease of elderly Mediterranean men. In 1989 AIDS data from 15 European countries were collected to study proportional trends in AIDS-related Kaposi's sarcoma (AIDS-KS) in order to determine whether specific factors in Southern Europe might be important in the development of KS among AIDS patients. Another AIDS-related cancer, non-Hodgkin's lymphoma (NHL) was included as a malignancy control. Of 22,367 AIDS cases reported, 3,779 (16.9%) were KS and 741 (3.3%) were NHL. A significant, continuous fall in the percentage of AIDS-KS was seen for both homosexual men and other members of exposure groups during the period 1981-89 (p-trend less than 0.0001). The proportion with AIDS-KS decreased from 40.5% in 1983 to 26.5% in 1988 in homosexual men and from 12.2 to 3.6% in other exposure groups, respectively. No significant change was observed in the proportion of NHL cases among any of the risk groups over time, although a tendency towards a slight increase was noted for homosexual men. Comparing proportional trends of KS and NHL geographically, no significant difference was found overall, by time or by exposure group. In conclusion, a specific decline is observed over time for AIDS-KS. However, if geographically-restricted factors are important in the development of non-AIDS-KS in Europe, the same factors do not appear to affect the risk of AIDS-KS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Antibody to human retroviruses among drug users in three east coast American cities, 1972-1976.

Between 1972 and 1976, 585 persons attending methadone maintenance clinics at East Coast veterans hospitals were enrolled in a survey of hepatitis antibody prevalence. Sera were tested for human immunodeficiency virus (HIV) and human T lymphotropic virus (HTLV) using both HTLV-I and HTLV-II immunoblots. Clinical and death records were also reviewed. None of the sera had HIV antibodies (upper 95% confidence limit, 0.5%); however, 103 (18%) had reactivity to HTLV. The profile of reactivity suggested that these subjects had been exposed to HTLV-II rather than to HTLV-I. Prevalence was as high in the early 1970s as today and correlated with duration of drug use rather than age. Neither cancers, specific neurologic diseases, nor excess deaths from any cause (overall 14%) could be ascribed to seropositivity. Therefore, HTLV (probably HTLV-II) has been a common infection of drug users for many years but adverse outcomes following infection were not demonstrated.

Adult↗
PubMed1991

Cigarette smoking: a modifier of human immunodeficiency virus type 1 infection?

Two hundred and two homosexual men enrolled in a prospective cohort study of AIDS risk were assessed for differences in the occurrence and progression of human immunodeficiency virus type 1 (HIV-1) infection with respect to cigarette smoking. Among subjects who were initially seronegative, smokers were more likely than nonsmokers to become HIV-1 seropositive (p = 0.03). After seroconversion, serum beta 2-microglobulin and CD4+ lymphocyte levels were elevated in cigarette smokers relative to nonsmokers (p = 0.02 for both comparisons), but both of these differences disappeared within 2 years. There was no detectable difference in the risk of AIDS or Pneumocystis carinii pneumonia with respect to smoking. Our data suggest that cigarette smoking may alter the immune response to HIV-1 infection, but it appears to have no marked effect on clinical outcome. They also suggest that cigarette smoking may be a surrogate marker for continued high-risk sexual behavior in homosexual men.

Adult↗
PubMed1991

Factors that could influence the spread of AIDS in Ghana, West Africa: knowledge of AIDS, sexual behavior, prostitution, and traditional medical practices.

Ghana is a West African nation in the early stages of the human immunodeficiency virus (HIV) epidemic. In a series of surveys done between 1987 and 1989, we examined factors related to the spread of HIV infection, including knowledge about the acquired immune deficiency syndrome (AIDS), sexual habits, use of prostitutes, traditional healer practices, and skin-piercing customs. Although a polygamous society, three-fourths of married men had only one wife. The number of sexual partners at any one time was generally low. However, the divorce rate was more than 29% and 55% of married men had current sexual partners in addition to their wives. Knowledge about AIDS was widespread, yet 4% of men interviewed had had a sexual encounter with a prostitute within the last month. Use of condoms was very limited and 66% of customers of high-class prostitutes refused to use a condom even after a request to do so by the prostitute. Skin piercing, including scarification, was done by an unsterile instrument by 39% of 74 rural traditional healers, many of whom had more than one patient per day. To combat the spread of AIDS, Ghanaians will have to apply their knowledge of AIDS risk factors to their actual behavior. Many of the social customs are products of poverty and its ensuing social consequences. Funds are needed for specific AIDS prevention programs as well as improved education and health care throughout the country.

Acquired Immunodeficiency Syndrome↗