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Biomedical subjects

S B Lucas

Publications and source records attributed to S B Lucas.

At least 19 recordsLinked to original sources
PubMed1996

Disease in children infected with HIV in Abidjan, Côte d'Ivoire.

OBJECTIVE: To document the range of disease in African children infected with HIV. DESIGN: Necropsy results in consecutive children aged 1 month or more who were HIV positive and in children who were HIV negative for comparison; IgA western blots on serum samples from children under 2 years of age who were positive for HIV-1 to test the validity of routine HIV serology. SETTING: Largest hospital in Abidjan, Côte d'Ivoire. SUBJECTS: 78 children who were HIV positive and 77 children who were HIV negative on whom a necropsy was performed; their median ages at death were 18 and 21 months respectively. 36 HIV positive children and 29 HIV negative children were 1-14 months old; 42 HIV positive and 48 HIV negative children were > or = 15 months old. MAIN OUTCOME MEASURES: Cause of death and prevalence of diseases confirmed pathologically. RESULTS: Respiratory tract infections were more common in HIV positive than in HIV negative children (73 (94%) v 52 (68%); P < 0.05), and were aetiologically heterogeneous. Pneumocystis carinii pneumonia was found in 11 out of 36 (31%) HIV positive children aged < 15 months, but in no HIV negative children. Among older children measles was more common in HIV positive children (8/42 (19%) v 2/48 (4%); P < 0.06). Pyogenic meningitis was present in similar proportions of HIV positive and HIV negative children aged < 15 months (7/36 (19%) and 7/29 (24%)). In HIV positive children tuberculosis (1/78), lymphocytic interstitial pneumonitis (1/78), and HIV encephalitis (2/78) were rare. CONCLUSIONS: There is greater overlap between diseases associated with HIV infection and other common health problems in African children than there is in adults. Compared with adults, HIV positive children had a high prevalence of P carinii pneumonia and a low prevalence of tuberculosis. Measles, but not malaria, was associated with HIV infection.

AIDS Dementia Complex↗
PubMed1996

Detection of polyomaviral DNA in clinical samples from immunocompromised patients: correlation with clinical disease.

Clinical samples from immunocompromised patients were screened for polyomaviral sequences by nested polymerase chain reaction (PCR) to evaluate the association of these viral infections with progressive multifocal leukoencephalopathy (PML). JC virus (JCV) DNA was detected in 19 of 23 CSF samples and all four brain samples from patients with PML. Neither BK virus (BKV) nor simian virus 40 (SV40) DNA were detected in these samples. No evidence was found to support the hypothesis that polyomaviral DNA is present in the central nervous system of immunosuppressed patients without PML (CSF n = 67, brain n = 19). JCV DNA was not detected in any peripheral blood sample included in this study. JCV DNA was detected in urine from three of eight patients with PML, but was also amplified from three of 29 urine samples from patients without PML, JCV, and not SV40 or BKV, was associated with PML in this study.

BK Virus↗
PubMed1996

Induction of Th1 cytokine responses by mycobacterial antigens in leprosy.

Twelve mycobacterial antigens were compared for induction of gamma interferon (IFN-gamma) secretion by human blood mononuclear cells of patients with leprosy. Fractionated Mycobacterium leprae antigens containing cell wall proteins or cytosolic and membrane proteins induced good IFN-gamma responses in tuberculoid leprosy patients. Lipoarabinomannan from M. tuberculosis Erdman and M. leprae mycolylarabinogalactan peptidoglycan were the poorest IFN-gamma inducers.

Antigens, Bacterial↗
PubMed1996

Carcinoma of the conjunctiva and HIV infection in Uganda and Malawi.

AIM: To investigate the association of human immunodeficiency virus (HIV) infection and carcinoma of the conjunctiva in Africa, and the role of human papilloma virus type 16 (HPV-16). METHODS: Patients in Uganda and Malawi presenting to eye clinics with lesions suspicious of carcinoma were studied. Pathological confirmation of eye lesions was sought. HIV testing of patients who were biopsied and, in Uganda, of matched case control subjects was carried out as was testing of a sample of fixed biopsies for HPV-16 by polymerase chain reaction (PCR). The HIV-1 serology, histopathology of conjunctival biopsies (conjunctival intraepithelial neoplasia (CIN), invasive carcinoma, other lesions), and prevalence of HPV-16 infection were determined. RESULTS: Of Ugandan patients, 27/38 (71%) with carcinoma (27 invasive carcinoma, 11, CIN) were HIV positive compared with 12/76 (16%) of controls (odds ratio 13, 95% confidence interval 5-38). The calculated population aetiological fraction of carcinoma associated with HIV was 66%. Of 32 Malawian patients (20 invasive carcinoma, 12 CIN), 25/29 tested (86%) were HIV positive. HPV-16 infection was found in 7/20 (35%) of carcinoma samples, 0/9 pingueculae, and 2/6 conjunctivitis samples. CONCLUSIONS: HIV infection is strongly associated with an apparent increase in the incidence of conjunctival carcinoma in Africa. While ultraviolet light is probably the prime risk factor and HPV-16 is implicated in a proportion of cases, the interactions of ultraviolet light, HIV, HPVs, and other factors are unclear in the pathogenesis of carcinoma. The disease represents another model of multifactorial epithelial carcinogenesis.

AIDS-Related Opportunistic Infections↗
PubMed1996

Fatal haemorrhage following liver biopsy in patients with HIV infection.

A retrospective review of all 248 liver biopsies performed in patients with HIV infection at two referral centres in London over a 12 year period revealed five cases of major bleeding following biopsy, with four deaths. The risk of major bleeding was 2.0%, and mortality was 1.6% following liver biopsy. The risk of bleeding as much higher than in published series of biopsies done in patients without HIV infection, owing in part to the high prevalence of thrombocytopaenia and clotting abnormalities in patients with HIV infection. HIV infection per se may also increase the risk of bleeding following liver biopsy.

Adult↗
PubMed1995

Tropical medicine for the 21st century.

The specialty of tropical medicine originated from the needs of the colonial era and is removed from many of the health care requirements of tropical countries today. Tropical medicine concentrates on parasitic diseases of warm climates, although other infections and diseases related to poverty rather than climate dominate medicine in developing countries challenged by population pressure, civil strife, and migration. In the new century, tropical medicine would best be absorbed into the specialty of infectious diseases, which should incorporate parasitic diseases, travel medicine, and sexually transmitted diseases. Pressing questions for health care and research in developing countries concern the provision of appropriate services for problems such as HIV/AIDS, tuberculosis, sexually transmitted diseases, and injuries. The question of how to provide appropriate clinical care in resource poor settings for the major causes of morbidity and premature mortality has been neglected by donors, academic institutions, and traditional tropical medicine.

Forecasting↗
PubMed1995

Testing for antibody to human immunodeficiency virus type 1 in a population in which mycobacterial diseases are endemic.

During a large epidemiologic study in the Karonga District of northern Malawi, serum samples from 139 patients with incident leprosy, 124 with newly diagnosed leprosy, 277 patients with incident tuberculosis, and 2296 controls were tested for antibodies to human immunodeficiency virus. Sera were tested according to a four-test protocol using two ELISAs and two particle agglutination assays. Overall, 188 samples were considered positive, 2634 were considered negative, and 14 were indeterminate. All 18 available positive specimens from leprosy patients, a random sample of 14 positive specimens from tuberculosis patients, and 15 positive specimens from controls were tested by Western blot. There was no evidence of substantial numbers of ELISA false-positives in any patient group or among controls.

Adult↗
PubMed1995

Immunohistochemical study of cutaneous neuritis in positive lepromin reactions.

Sixty skin biopsies taken from positive tuberculoid and borderline-tuberculoid late lepromin reaction were studied using histological techniques. The distribution of mycobacterial antigen and nerves was demonstrated using immunochemical methods. A total of 557 nerve bundles was observed in 51 biopsies; 9 were devoid of nerves in the sections examined; 475 nerve bundles showed some relationship to the inflammatory infiltrate (85%); perineuritis being seen in 144 (30%) and endoneuritis in 5 (0.9%). Mycobacterial antigens inside the granuloma were detected in 59 of the 60 biopsies (98%). Only one specimen, showing a strong tuberculoid reaction, failed to show these antigens. On the contrary, mycobacterial antigen was absent in almost all nerves. Small deposits were detected in the perineurium of one nerve with perineuritis, and inside a Schwann cell of another, the latter belonging to a previously multibacillary patient. The neurotropic tendency of the granuloma does not seem to be stimulated by the presence of mycobacterial antigens inside the nerves, as normally these antigens do not penetrate them. The hypothesis of some antigenic fraction of the neural tissue which cross-reacts with Mycobacterium leprae antigens, thus eliciting a perineural or near-perineural inflammatory reaction is put forward, but needs further investigation.

Antigens, Bacterial↗
PubMed1995

Clinical and histological discrepancies in diagnosis of ENL reactions classified by assessment of acute phase proteins SAA and CRP.

Sixteen out of 45 (36%) leprosy patients with clinical features of acute erythema nodosum leprosum (ENL) did not show the characteristic presence of neutrophils (polymorphs) in histology of the ENL lesion. The acute-phase reactants, serum amyloid A (SAA) and C-reactive protein (CRP) which are systemic markers of inflammation, and IgM and IgG antibody to Mycobacterium leprae were determined in these patients in order to understand the differences in histological diagnosis. Both SAA and CRP were elevated in ENL patients, irrespective of the presence of polymorph infiltrates, as compared to nonreactional lepromatous patients, patients with histologically confirmed reversal reactions and endemic controls, indicating that all clinically diagnosed ENL patients had ongoing inflammatory reactions. On the other hand, IgM and IgG antibodies were significantly lower (> 70%) in ENL patients as compared to nonreactional lepromatous patients. When the two ENL groups [ENL-PMN+ve (positive for neutrophils) and ENL-PMN-ve (negative for neutrophils)] were compared, there were no significant differences in the mean SAA, IgM or IgG antibody concentrations, but CRP was eightfold lower in ENL-PMN-ve as compared to the ENL-PMN+ve group. This may indicate that the timing or modulation of the reaction was different in the two ENL groups. Thus, measurement of the acute-phase response and the ratio of SAA/CRP in particular are helpful in the clinical diagnosis of ENL reactions in leprosy.

Adolescent↗
PubMed1994

HIV-associated lymphoma in Africa: an autopsy study in Cote d'Ivoire.

HIV infection predisposes to the development of non-Hodgkin lymphoma (NHL). The frequency of NHL among HIV-positive adults and children in sub-Saharan Africa is not known. In 1991-1992, a representative autopsy study of HIV infection was performed in Abidjan, Côte d'Ivoire. Of 247 HIV-positive adult (> 14 years) medical patients dying in hospital, 2.8% had NHL, 1.6% with visceral NHL and 1.2% with primary cerebral lymphoma. The estimated crude incidence of NHL among HIV-positive adults in Abidjan was 84/100,000 per year, 10-fold greater than the expected pre-AIDS incidence of NHL but less than the incidence observed among HIV-positive adults in industrialised countries. None of 78 autopsied HIV-positive children (median age = 17 months) had NHL. HIV infection augments the incidence of NHL among adults in Africa, but short survival with advanced HIV disease probably prevents the major increase in HIV-associated NHL seen in industrialised countries. Survival of HIV-positive children in Africa appears too short to permit the significant development of additional NHL; classic Burkitt lymphoma is not an AIDS-associated tumour in Africa.

Adolescent↗