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Biomedical subjects

S B Lucas

Publications and source records attributed to S B Lucas.

At least 55 records · Page 3Linked to original sources
PubMed1997

Comparison of magnetic resonance imaging with neuropathological findings in the diagnosis of HIV and CMV associated CNS disease in AIDS.

OBJECTIVES: To compare the results of clinical assessment and MRI with neuropathological findings in the diagnosis of HIV and cytomegalovirus (CMV) associated CNS disease. METHODS: A retrospective study of 35 patients infected with HIV who were examined at necropsy between four and 70 (median 20) days after neurological assessment and MRI. RESULTS: Of the 35 patients, 19 had diffuse white matter hyperintensity on T2 weighted MRI, six of whom also had focal lesions. Nine other patients had focal white matter lesions and seven had changes in cortical atrophy only. Necropsy in the 19 with diffuse white matter hyperintensity showed HIV leukoencephalopathy (HIVLEP) with encephalitis in 10, CMV encephalitis in three, both HIVLEP/HIV encephalitis and CMV encephalitis in one, lymphoma in three, and non-specific inflammation in two. Necropsy in the 16 other patients without diffuse white matter hyperintensity showed CMV encephalitis in six, HIV encephalitis (without HIVLEP) in two, CMV encephalitis and HIVLEP/HIV encephalitis in one, non-HIV associated abnormalities in five, herpes simplex encephalitis in one, and lymphoma in one. CMV DNA was detected in CSF of five of seven patients with CMV encephalitis and in two of two with CMV associated polyradiculopathy but without CMV encephalitis. Diffuse white matter hyperintensity on MRI had a sensitivity of 100%, a specificity of 66.6%, and a positive predictive value of 58% for diagnosis of HIVLEP. CONCLUSION: Diffuse white matter hyperintensity on MRI can be due to either HIV or CMV associated pathology or non-specific abnormalities.

Acquired Immunodeficiency Syndrome↗
PubMed1997

HHV8 and Kaposi's sarcoma: a time cohort study.

AIMS: The recent finding that human herpes virus 8 (HHV8) is found in the majority of Kaposi's sarcoma (KS) cases supports the epidemiological observation that the tumour may be caused by an infectious agent. This study aimed to address when and how HHV8 evolved. METHODS: A cohort of African endemic KS (49 samples from 45 patients) and European KS (18 samples from 13 patients), spanning 27 years, was assessed for the presence of HHV8 by both standard solution phase polymerase chain reaction (PCR) and the newly described technique of TaqMan PCR. RESULTS: HHV8 was present in approximately 49% (24 of 49 tissue samples) of the African cases and in more than 90% (16 of 18 tissue samples) of the European cohort, in keeping with recent seroepidemiological data. CONCLUSIONS: HHV8 is strongly linked to the development of KS; however, in some patients, other factors may operate. The utility and flexibility of TaqMan PCR in detecting low copy viral target in human tissues was demonstrated.

Adolescent↗
PubMed1997

The neuropathology of HIV-infected African children in Abidjan, Côte d'Ivoire.

In an autopsy study of HIV-infected children in Abidjan, Côte d'Ivoire, the neuropathology of 76 HIV-1- and 2 HIV-2-positive children was compared with that of 77 frequency-matched HIV-negative children, in whom the systemic pathology was also known. Seventy of the 78 HIV-seropositive children were confirmed as HIV-infected, as determined by combined serology, IgA Western blots and clinicopathological criteria. The HIV-negative children showed a high background level (n = 49, 64%) of neuropathological abnormalities, including nonspecific inflammatory infiltrates, micromineralization, and bacterial and lymphocytic meningitis. In the HIV-positive children, HIV encephalitis was found in 4 (6%), cytomegalovirus in 2 (3%), toxoplasmosis in 3 (4%) and measles encephalitis in one (1%). Bacterial meningitis was equally common in both groups, but cerebral malaria was less common (n = 2, 3%) in HIV-positive than in HIV-negative children (n = 11, 14%). The low prevalence of HIV encephalitis may reflect comparatively early death in HIV infection in Africa as compared with our experience in Europe and the US.

Acquired Immunodeficiency Syndrome↗
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↗