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Biomedical subjects

I G Williams

Publications and source records attributed to I G Williams.

At least 37 records · Page 2Linked to original sources
PubMed1997

Cerebral proton magnetic resonance spectroscopy in asymptomatic HIV infection.

OBJECTIVE: To determine whether proton magnetic resonance spectroscopy (MRS) demonstrates central nervous system abnormalities in asymptomatic HIV-1-infected individuals. DESIGN: Both prospective and retrospective cross-sectional analyses of MRS in asymptomatic HIV-infected individuals. SETTING: Two specialists HIV/AIDS outpatient facilities in London. PARTICIPANTS: Eighty-four HIV-1 seropositive asymptomatic men; 29 HIV-1 antibody-negative homosexual men at high-risk for HIV infection and 48 HIV-1 antibody-negative men at low-risk for HIV infection as controls. MAIN OUTCOME MEASURES: Single voxel, gradient-localized proton MRS performed at 1.5 T with 135 msec echo-time and 1,600 msec repeat-time in an 8 ml volume of interest positioned in the parieto-occipital white matter. Spectroscopic results were expressed as ratios between the areas under the N-acetyl (NA), creatine (Cr) and choline (Cho) resonance peaks. RESULTS: There were no differences between those controls at high and those at low-risk for HIV infection. Comparing the combined control groups with the asymptomatic seropositive patients there were statistically significant differences in NA/Cho, NA/Cr (both P < 0.05) and NA/(NA + Cho + Cr) (P < 0.01). CONCLUSION: Abnormalities in cerebral biochemistry may be demonstrated by proton MRS during asymptomatic HIV-1 infection.

Brain↗
PubMed1997

Detection of human herpesvirus-8 DNA in oral ulcer tissues of HIV-infected individuals.

OBJECTIVE: To determine the frequency of detection of human herpesvirus-8 (HHV-8) in HIV-related oral ulcers. DESIGN: Analysis of archived biopsy material. METHODS: Nested polymerase chain reaction of DNA extracts. RESULTS: HHV-8 DNA was detected in six of 10 oral ulcers of HIV-positive patients without oral Kaposi's sarcoma (KS) lesions and five of 11 oral KS lesions. The positive non-KS samples were derived from various oral sites. CONCLUSIONS: In HIV-positive people, HHV-8 can infect oral tissues that are not affected by KS.

AIDS-Related Opportunistic Infections↗
PubMed1997

Severe oral ulceration in patients with HIV infection: a case series.

OBJECTIVE: Oral ulceration occurs in an estimated 2-4% of patients with HIV infection. This retrospective observational study describes the aetiology and characteristics of 94 HIV-positive patients with either severe and/or recurrent oral ulceration presenting at a dedicated HIV dental unit over a 4-year period. METHODS: Case records were reviewed for diagnosis investigations, CD4 count, CDC stage and treatment modality. RESULTS: Of the 94 patients 50% had an AIDS diagnosis. In patients with asymptomatic HIV disease minor recurrent oral ulceration was the commonest diagnosis whilst large non-specific neutropenic ulcers were more frequently seen in patients with symptomatic disease with low CD4 counts. A variety of treatment modalities were used including thalidomide. An algorithm is presented for the management of patients with severe oral ulceration.

Acquired Immunodeficiency Syndrome↗
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

Proton Spectroscopy in a Cross-Section of HIV-Positive Asymptomatic Patients Receiving Immediate Compared with Deferred Zidovudine (Concorde Study).

The purpose of this study was to examine by proton spectroscopy for any difference in cerebral metabolites in patients taking part in the Concorde study (comparing the efficacy of immediate versus deferred treatment with zidovudine on asymptomatic HIV infected individuals). Forty seven HIV positive male patients [29 immediate, 18 deferred zidovudine] were examined in the last 9 months of the therapeutic trial. Magnetic resonance imaging and proton spectroscopy were performed at 1.5 Tesla using a single voxel placed in the parieto-occipital white matter. No significant difference was found in metabolite ratios comparing immediate versus deferred zidovudine (NA/NA+Cho+Cr 0.52 vs. 0.52). High quality spectra were acquired in relatively large numbers of patients and logistically spectroscopy may be applied to clinical therapeutic studies.

HIV Infections↗
PubMed1996

Immunization with recombinant p17/p24:Ty virus-like particles in human immunodeficiency virus-infected persons.

In studies of the natural history of human immunodeficiency virus type 1 (HIV-1) infection, it has been repeatedly shown that higher-titer antibody responses to the HIV gag p24 protein correlate with less rapid disease progression. In HIV-negative persons, immunization with HIV-1 p17/p24:Ty virus-like particles (p24-VLP) induced humoral and cellular immune responses to p24. This construct was therefore studied as a potential immunotherapeutic agent with the objective of augmenting the immune response to p24 in a double-blind placebo-controlled trial involving 74 p24 antibody-positive, asymptomatic HIV-1-infected subjects with CD4 cell counts > 350/mm3. Immunization with p24-VLP was generally well tolerated. Immunization with p24-VLP did not increase p24 antibody levels and had no effect on CD4 cell counts or virus load. The failure to increase p24 antibody titers cannot entirely be explained by the subjects' immunodeficiency because most generated an antibody response to Ty, a yeast component of the immunogen.

AIDS Vaccines↗
PubMed1996

A case control study of HIV seroconversion in gay men, 1988-1993: what are the current risk factors?

OBJECTIVE: To investigate current risk factors for HIV seroconversion among homo/bisexual men. DESIGN: Matched case control study in a large STD clinic in central London. Data on risk factors were obtained by case note review. METHODS: Fifty-six cases who had at least one negative HIV test followed by a positive test between June 1988 and July 1993, and two homo/bisexual controls (having two or more negative HIV tests) matched to each case on age, total number of HIV tests and test interval period were identified. Univariate and multivariate odds ratio were calculated for acute STD, ano-genital intercourse, condom use and HIV status of sexual partners. RESULTS: Adjusted odds ratios (95% confidence intervals) for HIV seroconversion were 4.1 (1.3-13.3) for having an acute interval STD and 4.6 (1.4-15.4) for having a known HIV infected sexual partner. Compared with men who always used condoms, odds ratios for men who sometimes or never used condoms were 7.9 (2.2-28.9) and 16.2 (3.0-86.0) respectively. Unprotected ano-genital intercourse was commonly reported by both cases and controls, and reported condom use was no greater with a known HIV infected partner than with a partner of unknown HIV status. CONCLUSION: HIV seroconversion among homo/bisexual men attending STD clinics is strongly related to having an acute STD, a known HIV infected partner and not using condoms. Although consistent use of condoms is highly protective, knowing that a partner is HIV infected does not ensure condom use between serodiscordant men. More effective, well-evaluated interventions are needed to reduce sexual risk-taking in this population.

Adolescent↗
PubMed1995

Cryptococcal pneumonia in patients with the acquired immunodeficiency syndrome.

Infection with Cryptococcus neoformans occurs with increased frequency in patients with the human immunodeficiency virus (HIV). Despite the lungs being the portal of entry for the fungus the commonest presentation is with meningitis: Cryptococcal broncho pulmonary infection occurs less commonly. The chest radiographs of fourteen HIV positive patients with cryptococcal pneumonia were reviewed. The commonest radiographic abnormalities were interstitial infiltrates, (nine patients) and focal or widespread alveolar consolidation (seven patients). Ground glass shadowing, not previously described in cryptococcal pneumonia, occurred in six radiographs, miliary nodules in one, lymphadenopathy in four, and small pleural effusions in three. Two patients had a normal chest radiograph. In contrast to previous reports, we found alveolar consolidation and ground glass shadowing to be common and nodules and cavitation to be rare. Cryptococcal pneumonia should be considered in the differential diagnosis of Pneumocystis carinii pneumonia, bacterial pneumonia and miliary tuberculosis in HIV positive patients.

AIDS-Related Opportunistic Infections↗
PubMed1992

Auditing AIDS reporting. Experience from a central London district 1982-1991.

OBJECTIVE: To evaluate completeness of reporting of cases of AIDS to the Communicable Disease Surveillance Centre (CDSC) between 1982-1991. SETTING: Southside of the Bloomsbury and Islington District Health Authority. DESIGN: Reconciliation exercise with CDSC of cases reported with those known to have received treatment in the district from 1982 to March 1990. Case note review of unreported cases and follow-up at March 1991. MAIN OUTCOME MEASURES: Delayed and non-reporting of cases. RESULTS: Cumulatively 13% (46/351) of patients whose initial AIDS illness was diagnosed in the District remained unreported by March 1991. Non-reporting increased from 9% (2/23) of cases diagnosed prior to 1985 to 28% (26/92) of cases diagnosed between 1989 and 1990. After September 1987 the proportion of patients with a diagnosis of Pneumocystis carinii pneumonia or Kaposi's sarcoma was significantly higher in the reported group than in the non-reported group: 78% (124/158) v 51% (24/49) p < 0.001. Nine of 19 (47%) cases of AIDS transferring their care into the district had not been reported by their previous District Health Authority. CONCLUSIONS: Within the district non-reporting of cases of AIDS has risen over time as the numbers of patients treated has increased. The physician must be aware of the full AIDS case definition for surveillance purposes and the implications of non-reporting for the allocation of special "ring-fenced" resources for AIDS care. Adequate investment in information and reporting systems would seem essential.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Response of serum p24 antigen and antibody to p24 antigen in patients with AIDS and AIDS-related complex treated with zidovudine.

In an open study of the treatment of patients with AIDS-related complex (ARC) and AIDS with zidovudine, we evaluated the response of serum p24 antigen (p24Ag) and antibody to p24Ag (anti-p24) levels. Before treatment, serum from 49 out of 73 (67%) patients was p24Ag-positive, and of these patients 42 received zidovudine 800-1200 mg daily for greater than 4 weeks and had a baseline mean serum level of p24Ag of 119 pg/ml (s.e. 15.7). On zidovudine there was a reduction of p24Ag to 21.12% (s.e. 4.76) of pretreatment values at 3 months; however, there was a subsequent trend for levels after 6 months to increase to greater than 50% of pretreatment levels at 12 months. Serum levels of anti-p24 were measured in 26 patients. Of 16 patients whose serum contained p24Ag and 10 whose serum did not, four and nine, respectively, had detectable levels of anti-p24. There was no significant change in the serum anti-p24 with zidovudine therapy.

AIDS-Related Complex↗
PubMed1984

A case of Klinefelter's syndrome with acquired hypopituitarism.

The association of Klinefelter's syndrome (KS) and hypopituitarism has been described in previous isolated case reports, in most of which the hypopituitarism was partial. A case is described of a man with KS who acquired hypopituitarism in adult life. The diagnosis of KS was made at the age of 25 years on standard laboratory tests when he presented with failure of ejaculation and typical clinical features. Thirteen years later he presented with anaemia and further regression of secondary sexual characteristics. All aspects of anterior pituitary function were abnormal. The cause of the hypopituitarism was not determined, but may have been post-traumatic.

Adult↗