Search PubMed⌕ Search

Biomedical subjects

B Tindall

Publications and source records attributed to B Tindall.

At least 37 records · Page 2Linked to original sources
PubMed1993

Factors associated with Kaposi's sarcoma in a cohort of homosexual and bisexual men.

The relationship between the occurrence of Kaposi's sarcoma (KS) and a range of factors was studied in a cohort of homosexual and bisexual men. Overall, 134 men had AIDS, including 46 for whom KS was the first AIDS-defining illness. The proportion of men diagnosed with AIDS whose first AIDS-defining illness was KS declined from 54 to 24% between 1984-85 and 1989-90 (p = 0.03 for linear trend). Kaposi's sarcoma was not associated with a history of any specific communicable disease, nor with the reported use of selected nontherapeutic drugs, at the 0.05 level of significance. No single sexual practice was significantly associated with KS, and only the relative risks for insertive oroanal contact (1.5, 95% confidence limits 0.73-2.4) and receptive fisting (1.3, 0.61-2.6) exceeded unity. Kaposi's sarcoma occurred significantly less frequently in men who reported orogenital intercourse than in those who did not (relative risk 0.47, 0.23-0.98 for receptive orogenital intercourse). History of sexual contact in the United States was associated with KS, but this association was not statistically significant. While this study provides some support for the hypothesis that Kaposi's sarcoma in people with AIDS may be caused by a sexually transmissible infectious agent, no specific sexual practice could be implicated. In particular, there was little evidence that the postulated KS agent was transmitted by fecal-oral contact.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Long-term symptomless HIV-1 infection in recipients of blood products from a single donor.

There have been reported cases of long-term symptomless human immunodeficiency virus type 1 (HIV-1) infection, but it is not clear whether the benign course of infection was due to host, viral, or other unknown factors. During follow-up of subjects with transfusion-acquired HIV-1 infection in New South Wales, Australia, we identified a group of 6 subjects who had been infected through a single common donor. We were therefore able to study the contributions of various factors to the course of infection. Throughout follow-up (range 6.8-10.1 years after infection), 5 of the recipients and the donor (last follow-up 10.2 years after infection of the first recipient) remained clinically free of symptoms, with normal CD4 cell counts and no p24 antigenaemia. HIV-1 was isolated from only 1 recipient; the isolate did not induce syncytia in a SUPT1 co-culture assay and had a limited in-vitro host range. 1 infected recipient (who had received extensive immunosuppressive treatment for systemic lupus erythematosus) developed Pneumocystis carinii pneumonia and died 4.3 years after infection. The frequency of progression to AIDS or a CD4 cell count below 0.50 x 10(9)/l was significantly lower among the 6 subjects with a common donor (1/6) than among 101 other HIV-infected transfusion recipients for whom data from 7 years of follow-up were available (94/101; p less than 0.0001). These findings suggest that the subjects were infected by a less virulent strain of HIV-1. The identification of this group of subjects should stimulate a search for other similar groups, which will provide important information on the immunopathogenesis of HIV-1 disease.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Low-dose trimethoprim-sulfamethoxazole prophylaxis for toxoplasmic encephalitis in patients with AIDS.

OBJECTIVE: To determine the efficacy of low-dose trimethoprim-sulfamethoxazole (trimethoprim, 160 mg plus sulfamethoxazole, 800 mg; one tablet twice daily, 2 days per week) as primary prophylaxis against toxoplasmic encephalitis in patients with human immunodeficiency virus (HIV) infection and previous Pneumocystis carinii pneumonia. DESIGN: A retrospective study. SETTING: Tertiary referral teaching hospital. PATIENTS: During a 3-year period after primary episodes of P. carinii pneumonia, 60 patients received trimethoprim-sulfamethoxazole, and 95 patients received pentamidine (aerosolized in 78 patients and intravenous in 17 patients) as secondary prophylaxis. RESULTS: No patient in the trimethoprim-sulfamethoxazole group and no patient seronegative for Toxoplasma gondii developed toxoplasmic encephalitis, compared with 12 of 36 (33%; 95% Cl, 19% to 51%) seropositive patients in the pentamidine group (trimethoprim-sulfamethoxazole compared with pentamidine, P = 0.008). A significant difference was seen in the time to development of toxoplasmic encephalitis between the trimethoprim-sulfamethoxazole group (no case at 1153 days) and the pentamidine group (median time, 460 days) (P = 0.004). Neither the CD4+ lymphocyte count at the start of prophylaxis nor zidovudine therapy during the period of prophylaxis influenced the rate of toxoplasmic encephalitis in any group. CONCLUSIONS: Low-dose trimethoprim-sulfamethoxazole (four tablets per week) appears to be effective prophylaxis against toxoplasmic encephalitis in HIV-infected patients with previous P. carinii pneumonia. A prospective, randomized, controlled study is needed to further evaluate these findings.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Trimethoprim-sulphamethoxazole appears more effective than aerosolized pentamidine as secondary prophylaxis against Pneumocystis carinii pneumonia in patients with AIDS.

OBJECTIVE: We compared the efficacies of low-dose trimethoprim-sulphamethoxazole (TMP-SMX; one tablet: TMP, 160 mg, SMX, 800 mg, twice daily, twice a week) and aerosolized pentamidine (300 mg every 4 weeks) as secondary prophylaxis against Pneumocystis carinii pneumonia (PCP) in patients with HIV infection. DESIGN: A retrospective controlled study. SETTING: The study was performed at St Vincent's Hospital, Sydney, Australia, which is a tertiary referral university hospital. PATIENTS, PARTICIPANTS: Over a 4-year period, following primary episodes of PCP, 60 patients received TMP-SMX and 73 aerosolized pentamidine. Thirty-eight patients who received no secondary prophylaxis served as historical controls. MAIN OUTCOME MEASURES: The rate of and time to PCP relapse was recorded for patients receiving low-dose TMP-SMX, aerosolized pentamidine, or no prophylaxis. RESULTS: Only one (1.7%) patient in the TMP-SMX-treated group relapsed, compared with 31 (42.5%) of those in the aerosolized pentamidine group and 21 (55.1%) of those in the control group (P less than 0.0001). Median PCP-free survival times were greater than 1153 days in the TMP-SMX group, 496 days in the pentamidine group, and 265 days in the control group (P less than 0.0001 between all groups). The rate of or time to relapse was not influenced by CD4+ lymphocyte count at the start of prophylaxis, primary therapy of PCP, history of allergy to TMP-SMX, or zidovudine therapy during the period of secondary prophylaxis in any patient group. Both therapies were well tolerated, with three (5%) of those receiving TMP-SMX and four (5%) of those receiving pentamidine discontinuing therapy as a result of side-effects. CONCLUSIONS: Low-dose TMP-SMX appears to be more effective compared with aerosolized pentamidine as secondary prophylaxis against PCP in HIV-infected patients. Zidovudine was well tolerated by both groups, but did not influence the rate of or time to relapse.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Identification of HIV-1 in semen following primary HIV-1 infection.

OBJECTIVE: To determine whether HIV could be identified in semen samples during the first few weeks after infection. DESIGN: A series of three homosexual men with symptomatic primary HIV-1 infection. METHODS: Each subject provided a series of semen samples that was examined for HIV-1 by virus culture, polymerase chain reaction (PCR) and transmission electron micrography. RESULTS: The first samples obtained for each subject (17, 22 and 24 days following onset of primary HIV-1 infection) were all positive by PCR and negative by viral culture. Of 13 samples obtained during the first 80 days after onset of primary HIV-1 infection and analysed by PCR, 10 were positive. Only one of these samples was virus culture-positive. Four semen samples obtained from two subjects during treatment with zidovudine were PCR-positive. Eight samples were examined for presence of HIV-1 by electron microscopy and one was found to be positive. CONCLUSIONS: These results indicate that men with HIV-1 infection are potentially infectious through sexual transmission during the first few weeks after infection. The findings emphasize that individuals in all stages of HIV-1 infection should practise safer sex to reduce transmission of HIV-1.

Adult↗
PubMed1992

Effect of the revised CDC case definition of AIDS on the number of AIDS cases in the Sydney AIDS Prospective Study.

We sought to evaluate the potential impact of a proposed revision in the case definition of acquired immunodeficiency syndrome (AIDS) (from a clinical case definition to one also including subjects with HIV infection who have an absolute number of peripheral CD4+ cells of less than 200 x 10(6)/L) among 512 HIV-seropositive homosexual/bisexual who were reviewed between 1984 and 1991. According to the current case definition, 151 (30%) of 512 at-risk subjects developed AIDS between 1984 and August 1, 1991. Of the 361 at-risk subjects who were not classified as AIDS by the current definition, 47 (13%; 95% CI 9-17%) were classified as AIDS according to the revised definition. The median time to development of AIDS according to the revised definition was 288 weeks and that according to the current definition was 338 weeks. Data on clinical status were available for 34 of the new cases at the time of their diagnosis according to the proposed case definition: 16 (47%) of these were asymptomatic, 10 (29%) had persistent generalised lymphadenopathy and eight had minor infectious diseases. Of the 151 cases diagnosed according to the current definition, 78 (52%) had an antecedent CD4+ cell count that met the criteria for AIDS under the revised definition a median of 59 weeks before their diagnosis according to the current definition. These data indicate an appreciable increase in the number of cases of AIDS in this cohort when the revised case definition was applied. These findings have important implications for the surveillance, and for the clinical monitoring and treatment, of patients with HIV disease in Australia.

Acquired Immunodeficiency Syndrome↗
PubMed1991

CD4% is the best predictor of development of AIDS in a cohort of HIV-infected homosexual men.

To determine the relationships between individuals' baseline T-cell subsets, their rates of change with time, and AIDS-free survival time, data were collected at 6-monthly intervals from 379 HIV-seropositive homosexual Sydney men, of whom 31 developed AIDS during the 3-year observation period. Both CD4% and rate of change of CD4% in an individual had significant prognostic value in determining AIDS-free survival time. Compared with subjects whose CD4% remained stable, subjects whose CD4% dropped by 7% or more in a year had a relative hazard of 35.1 (95% confidence interval = 11.7-105.6, P less than 0.001) of developing AIDS. Increasing CD4% had a significant protective effect, reducing the risk of developing AIDS. CD4%, CD4 cell count and CD4: CD8 ratios showed steeper declines in subjects who were later diagnosed with AIDS than in those who remained AIDS-free. The rates of immunological change in AIDS-free seroconverters and seropositives were similar, despite indeterminate differences in durations of infections. In the multivariate Cox regression analysis, baseline CD4%, the rate of change of CD4%, and baseline lymphocyte count were associated with AIDS-free survival time. Baseline CD4% had greater prognostic value than baseline CD4 cell count. Baseline CD8%, baseline CD8 count, their rates of change and their mean square errors were not independently significant in this analysis. These findings are important for clinicians monitoring HIV infection in an individual and for entry criteria and monitoring procedures in clinical trials. They also have implications for resource-poor settings; prognosis based on CD4% can be made with a flow cytometer without a full blood count.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1991

Zidovudine in the management of primary HIV-1 infection.

Eleven subjects who presented with a clinical illness characteristic of primary HIV-1 infection were treated with 1 g zidovudine daily for a median period of 56 days (range, 28-111 days). Primary HIV-1 infection was confirmed in each subject by seroconversion and virus isolation. The acute phase of the illness resolved a median of 4 days (range, 3-14 days) from commencement of zidovudine. Six subjects reported symptoms that may have been side-effects of zidovudine, the most common being nausea in four subjects and headache in two. Treatment was discontinued in one subject who had persistent headache and nausea. Haemoglobin, haematocrit and erythrocyte counts decreased and mean corpuscular volume increased significantly during the treatment. None of the subjects developed anaemia and none required dose modification or blood transfusion as a result of haematological side-effects. There were no significant differences in the granulocyte count or the lymphocyte count during any week of treatment when compared with baseline levels. There were no significant differences in T-cell subset numbers of the subjects during treatment compared with a group of historical controls. HIV-1 was isolated from several subjects during and after termination of zidovudine treatment. The results of this investigation indicate that zidovudine is a safe drug to administer to people with primary HIV-1 infection. There was no clear evidence, however, of any clinical benefit in terms of resolution of the acute illness and no indication that the treatment would prevent development of persistent infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1990

Development of AIDS in a cohort of HIV-seropositive homosexual men in Australia.

The Sydney AIDS Prospective Study is a cohort study of 1057 homosexual men enrolled between February 1984 and January 1985. By June 30, 1989, 111 (26.8%) of the 414 men who were seropositive for antibodies to human immunodeficiency virus (HIV) at enrollment had developed the acquired immunodeficiency syndrome (AIDS). On univariate analysis the following baseline factors were significantly associated with subsequent development of AIDS: splenomegaly; a lymphocyte count less than 1500 x 10(6)/L; a percentage of CD4+ cells less than 20% of the total lymphocyte count; an absolute number of CD4+ cells less than 200 x 10(6)/L; and a CD4+: CD8+ ratio less than 1.00. In a proportional hazards model the following factors retained significance: a lymphocyte count less than 1500 x 10(6)/L; an absolute number of CD4+ cells less than 200 x 10(6)/L; and a CD4+: CD8+ ratio less than 1.00. A CD4+ cell count less than 200 x 10(6)/L carried the greatest relative risk (3.99) for the development of AIDS. This study has confirmed that the appreciable rates of progression to AIDS demonstrated in overseas cohorts of HIV-infected persons also apply in the Australian context. A number of laboratory variables was found to be predictive for the subsequent development of AIDS. As we were not able to determine accurately whether subjects were receiving antiretroviral treatment or prophylaxis for opportunistic infections the observed rates in this study should be seen as minimum estimates. These findings have important implications for HIV-infected persons and for public health planning, and emphasise the need for regular clinical monitoring and T-cell subset enumeration in HIV-infected persons.

Acquired Immunodeficiency Syndrome↗