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Biomedical subjects

J W Carswell

Publications and source records attributed to J W Carswell.

At least 19 recordsLinked to original sources
PubMed1994

Reactions of Ugandan antisera with peptides encoded by V3 loop epitopes of human immunodeficiency virus type 1.

The specificities of antibodies reacting with peptides encoded by V3 loop apical epitopes were determined for sera from 230 seropositive Ugandans, including asymptomatic persons and AIDS patients, sampled between 1986 and 1992. Most (71%) of the sera reacted with the peptide encoded by HIV-MN, 59% reacted with a peptide containing a consensus sequence for Ugandan variants of the HIV-1 global subtype A (referred to as the Uganda A consensus), 59% reacted with a peptide containing a consensus sequence for Ugandan variants of the global subtype D (the Uganda D consensus); 19% of the sera also reacted with peptides encoded by the divergent Ugandan variant U31. There was no obvious correlation between the specificities of antibody binding and the V3 loop sequence of the corresponding virus isolate or provirus. Competitive inhibition and antibody adsorption experiments indicated that the MN peptide, the Uganda A consensus peptide, the Uganda D consensus peptide, and the U31 peptide were recognized by different sets of antibodies. Eighteen percent of the sera from AIDS patients and 26% of the sera from asymptomatic persons were monospecific for one of the MN, Uganda A, or Uganda D peptides. Whereas all except one of the singly reactive AIDS sera were specific for MN, 39% of the singly reactive asymptomatic sera were specific for MN, 39% for the Uganda A peptide, and 21% for the Uganda D peptides. We conclude that analysis of the specificities of antibodies against the V3 loop epitopes in sera from asymptomatic persons could provide useful epidemiological data about the prevalence of viral subtypes within a population.

Adult↗
PubMed1992

A review and assessment of non-governmental organization-based STD/AIDS education and prevention projects for marginalized groups.

A review of projects run by non-governmental organizations (NGOs) in primarily developing countries, which have aimed to provide STD/AIDS education and prevention skills to various marginalized groups, reveals that past quantitative and formative research has failed to identify key programmatic factors which lead to more successful project implementation and sustainability. In observations, interviews with field staff, visits to program sites and information drawn from the literature, a variety of methods to reach a wide range of groups such as men who have sex with men, prostitutes, clients of prostitutes, prisoners, street children, migrant workers and refugees are explored. Factors found to facilitate project success include the following: at least one full-time committed staff member; respectful treatment and appropriate motivation of the target group; suitable and sufficient equipment and supplies (particularly condoms); planning ahead for the participation of HIV-positive individuals and ways to meet their needs; focusing on qualitative rather than quantitative evaluation; planning in advance beyond a 9 or 12 month 'model'. Despite some evidence that marginalized groups can be successfully motivated to practise safer sex through prevention education, long-term behaviour change still presents major challenges--even when specific conditions are met.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Nucleotide sequence of a Ugandan HIV-1 provirus reveals genetic diversity from other HIV-1 isolates.

A Ugandan isolate of human immunodeficiency virus type 1 (HIV-1), designated U455, was adapted to growth in U937 cells, the provirus cloned into the lambda L47.1 vector, and its DNA sequence determined. The sequences of some of the U455 genes showed a marked divergence from those of North American and other African isolates. The sequenced clone was defective with single in-phase stop codons in the vpr and env genes and frame shift, resulting in a stop codon, within the vpu gene.

Adult↗
PubMed1989

Prevalence of HIV-1 in east African lorry drivers.

Sixty-eight lorry drivers and their assistants were examined for evidence of infection with HIV-1 because of their association and regular contact with prostitutes. Out of a total of 68 drivers, 24 (35.2%) were serologically found to be HIV-1 positive. Epidemiological evidence demonstrated a wide travel history involving seven different countries served by the port of Mombasa. History of other sexually transmitted disorders were significantly higher in HIV-seropositive individuals. The data presented here further support the hypothesis that a major route of heterosexual transmission of HIV in Africa is dissemination through a group such as lorry drivers and their assistants, whose behaviour puts them at risk of acquiring sexually transmitted diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Enteropathic AIDS in Uganda. An endoscopic, histological and microbiological study.

Twenty-three Ugandan patients with enteropathic acquired immunodeficiency syndrome (AIDS, 'slim' disease) were studied. Upper gastrointestinal (GI) endoscopy, colonoscopy, biopsy, stool parasitology and culture were performed. Endoscopy revealed oral and/or oesophageal candidiasis in 22 patients. Stool examination and histology of the upper GI tract showed that 11 patients had cryptosporidiosis and three had isosporiasis (total of 61% of patients with coccidian enteritis). One case of possible Mycobacterium avium mycobacteriosis was also identified. Enteropathic AIDS in Uganda presents with a spectrum of infections similar to that found in developed countries, but the incidence of cryptosporidiosis and isosporiasis is higher.

Acquired Immunodeficiency Syndrome↗
PubMed1987

HIV infection in healthy persons in Uganda.

The results of several serological surveys, carried out in Uganda in the last 2 years, show that HIV infection is present in a number of different groups of individuals. There is a wide range of seropositivity (0 to 67.7%) seen within Uganda. In the sexually inactive, whether primary school pupils or residents of old people's homes, no serological evidence of HIV infection was found. In young adults in Kampala the HIV seropositivity ranged from 10.6 to 24.1%, whereas in rural adults the range was from 1.4 to 12.5%. Those with the greatest number of lifetime sexual partners had the highest rate of seropositivity, ranging from 32 to 67.7%. These rates are probably dependent on a number of factors, including sexuality.

Acquired Immunodeficiency Syndrome↗
PubMed1987

HIV infection through normal heterosexual contact in Uganda.

One hundred and fourteen household contacts of 23 patients with AIDS or suspected AIDS were examined for evidence of infection with HIV. In total 12 contacts had antibodies to the virus by a competitive enzyme-linked immunosorbent assay (ELISA), confirmed by Western blot. Ten of these seropositive contacts were the sexual partners of the index cases. Overall 71% of sexual partners (10:14) were seropositive. By contrast only 2:100 of the non-sexual contacts had evidence of infection. These were the daughter of an index case and her 2-year-old son who were seropositive but had their own independent risk factors. The data presented here support the hypothesis that a major route of transmission of HIV in an African population is through heterosexual contact and furthermore suggest that transmission by other means such as intimate non-sexual contact, insect vectors, or the use of non-sterile needles is much less important.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Slim disease: a new disease in Uganda and its association with HTLV-III infection.

A new disease has recently been recognised in rural Uganda. Because the major symptoms are weight loss and diarrhoea, it is known locally as slim disease. It is strongly associated with HTLV-III infection (63 out of 71 patients) and affects females nearly as frequently as males. The clinical features are similar to those of enteropathic acquired immunodeficiency syndrome as seen in neighbouring Zaire. However, the syndrome is rarely associated with Kaposi's sarcoma (KS), although KS is endemic in this area of Uganda. Slim disease occurs predominantly in the heterosexually promiscuous population and there is no clear evidence to implicate other possible means of transmission, such as by insect vectors or re-used injection needles. The site and timing of the first reported cases suggest that the disease arose in Tanzania.

Acquired Immunodeficiency Syndrome↗
PubMed1977

Multiple skin testing of tuberculosis patients with a range of new tuberculins, and a comparison with leprosy and Mycobacterium ulcerans infection.

Four hundred and seventy tuberculosis patients were each skin tested with four of a range of 17 mycobacterial reagents in four countries in all of which tuberculosis and leprosy were endemic. Sixteen of the reagents were new tuberculins prepared from extracts of living mycobacteria disrupted by ultrasonic disintegration and the last was PPD, RT23.The effect that tuberculosis exerted on the delayed-type skin test response to these antigens was assessed by comparing results for tuberculosis patients with those for Tuberculin positive and Tuberculin negative control populations. Tuberculosis patients on Rifampicin therapy showed no difference in their skin test responses to any of the antigens from those patients on other forms of antituberculosis treatment.Amongst the normal population it was found that possession of Tuberculin positivity was associated with an enhanced response to all the other mycobacterial antigens with the exception of A(*)-in which demonstrated a reciprocal relationship with Tuberculin in Burma. It was also noted, in Burma particularly, that sensitization to mycobacterial species other than Mycobacterium tuberculosis, especially to the slow growers, plays a role in determining responses to different mycobacterial species.In tuberculosis patients enhanced skin test responses were also seen but only in those countries, e.g. Libya, where the prevalence of mycobacterial species was low. Where mycobacteria were common, as in Burma, the converse was true and tuberculosis was associated with a diminished skin test response to each antigen. The high prevalence of A(*)-in positivity in Burma, its reciprocal relationship with Tuberculin there and the results for all the antigens in the tuberculosis patients indicate that the cell mediated skin test response may have a threshold. If this is exceeded the skin test becomes negative so that non-reactors then include those who have been excessively sensitized as well as those who have not been sensitized. Despite this, a greater percentage of tuberculosis patients in each country responded to the specific reagent Tuberculin than did the control populations and their mean positive induration sizes were consistently larger. Nevertheless, amongst the tuberculosis patients in Burma 13% were complete non-reactors to Tuberculin and this apparent anergy also applied to the other reagents with which these individuals were tested.This differs from lepromatous leprosy where the anergic state pertains exclusively to M. leprae and a few seemingly closely related species. The breadth of anergy in M. ulcerans infection has not been measured but it is known to effect both Burulin and the PPD, RT23.Just as in leprosy and M. ulcerans infection, tuberculosis can be shown to have a disease spectrum here detected by multiple skin testing. The significance of this spectrum and its similarities with and differences from that of the other mycobacterioses is discussed.

Adolescent↗
PubMed1976

Preliminary evidence for the trapping of antigen-specific lymphocytes in the lymphoid tissue of 'anergic' tuberculosis patients.

Lymphocyte-transformation responses to mycobacterial antigens have been studied, using paired blood and lymph node samples from 'normal' Ugandans, (hernia repairs or orthopaedic cases) or from patients with tuberculosis, Mycobacterium ulcerans infection, or injection abscesses. The results suggest that in some individuals, antigen reactive cells, although absent from the periphery, may be demonstrable in the lymph nodes. This phenomenon is most striking in skin-test negative tuberculosis patients.

Antigen-Antibody Reactions↗