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Biomedical subjects

D Pillay

Publications and source records attributed to D Pillay.

At least 73 records · Page 4Linked to original sources
PubMed1999

Urinary levels of tissue kallikrein in the South African Black and Indian hypertensives.

It is accepted that Black subjects differ from White and Indian hypertensives in their response to hypotensive agents. Black hypertensives in the USA have a lower urinary tissue kallikrein (TK) excretion levels compared to White hypertensives. It has been suggested that Black patients respond better to thiazide diuretics compared to beta-blockers because thiazides increase whereas beta-blockers decrease tissue kallikrein excretion. This study compares the excretion of urinary TK in Black and Indian hypertensive and normotensive subjects. Urinary TK levels were measured with the selective, synthetic peptic substrate with the sequence of H-D-Val-Leu-Arg-pNA. Ten hypertensive patients on placebo therapy and 10 normotensive Black and Indian subjects provided three samples at weeks 0, 2 and 4 for the determination of urinary TK. The results were analysed using analysis of variance to compare the two racial groups. There were no significant differences in urinary TK values of the three bi-weekly individual samples. Urinary tissue kallikrein values (ng TK/microg protein) in Indian hypertensives were in general lower than Black hypertensives.

Adult↗
PubMed1999

Chronic erosive herpes simplex virus infection of the penis, a possible immune reconstitution disease.

OBJECTIVE: To report a novel clinical presentation: a chronic erosive herpes simplex virus (HSV) infection of the penis which developed in AIDS patients following the commencement of highly active antiretroviral therapy (HAART). The lesions were unresponsive to antiviral treatments which had previously been effective, and this could not be accounted for in terms of increased antiviral resistance. DESIGN: Detailed case-note review and investigation of three cases which presented at two large HIV units in London. METHODS: Review of all histology with immunohistochemistry for HSV, HSV drug susceptibility assays, tissue typing and measurement of in vitro lymphocyte functional activity against HSV. RESULTS: The histology of the lesions was the same in each case, with the presence of HSV on immunohistochemistry and an unusual prominence of plasma cell and eosinophils in the inflammatory infiltrate. HSV-specific lymphoproliferative responses were normal in two cases, but subnormal in a third case. All individuals shared the HLA class I molecules B72 and Cw0202 and the class II allele DRB4. CONCLUSION: We believe this to be a previously unreported adverse consequence of HAART, the result of partial immune restoration, reminiscent of the the recently described syndrome of immune recovery vitritis.

AIDS-Related Opportunistic Infections↗
PubMed1999

Use of real-time PCR and fluorimetry to detect lamivudine resistance-associated mutations in hepatitis B virus.

Very rapid amplification of DNA by PCR in small volumes can be continuously monitored by the detection of the binding of probes with a rapid cycler with built-in fluorometric detection. Primers were designed to amplify approximately 100 bp of the polymerase gene of hepatitis B virus (HBV) spanning codon 550, where mutations associated with resistance to lamivudine invariably occur. Four hybridization probes were synthesized: one was 3' labelled with fluorescein and hybridized upstream of codon 550. The others were 5' labelled with Cy5 and 3' labelled with biotin and spanned codon 550. The Cy5-labelled oligonucleotides contained either wild-type (ATG) or mutant (GTG or ATT) sequences. A Cy5-labelled probe and either the fluorescein-labelled probe or Sybr Green 1 (a compound that fluoresces when bound to double-stranded DNA) were included in each PCR. After completion of the amplification by using a LightCycler (Idaho Technology), the temperature at which the Cy5 probe melted from the product was determined in a melt program that took ca. 3 min. Pre- and posttreatment samples from eight patients (five chronic and three transplant) who failed lamivudine treatment were amplified, and the presence of mutations in codon 550 was determined by ABI sequencing and by using the LightCycler; in some cases PCR products were also cloned, and multiple clones were sequenced. Concordant results were obtained in all cases. We found the LightCycler to be better at resolving the sequences of genomic mixtures; for example, two samples showed a sequence at codon 550 of (A/G)T(G/T), which was found by fluorimetry to be mixtures of GTG and ATT but no ATG, and this finding was confirmed by the sequencing of clones. However, this approach was not more sensitive than population sequencing for the detection of the presence of mixtures. Overall, this pilot study has demonstrated an approach that could be an extremely rapid and economical method for the detection of lamivudine resistance-associated mutations in HBV.

Anti-HIV Agents↗
PubMed1999

Asymptomatic urethritis and detection of HIV-1 RNA in seminal plasma.

OBJECTIVE: To define risk factors for detection of HIV-1 RNA in semen in men attending the two largest HIV clinics in the West Midlands. METHODS: 94 HIV-1 seropositive men at any stage of infection donated matched semen and blood samples. 36 subjects (38%) were on no antiretroviral treatment, 12 (13%) were on dual therapy, and 46 (49%) were on three or more drugs. Median CD4 count was 291 cells x 10(6)/l. 87 subjects underwent a urethritis screen (Gram stained urethral smear and culture for gonococcus, and LCR for Chlamydia trachomatis on first pass urine). Quantitative cell free HIV-1 RNA was determined by commercial nucleic acid sequence based assay with a lower detection limit of 800 copies/ml for semen and 400 copies/ml for blood. Independent risk factors for seminal HIV RNA detection were defined by logistic regression. RESULTS: In univariate analysis, subjects not taking antiretrovirals were 11 times more likely to shed HIV RNA (21/36 (58%) v 6/58 (10%); p < 0.0001). Seven subjects (8%) had urethritis (including one C trachomatis infection). Urethritis was significantly associated with detection of seminal HIV RNA (adjusted OR, 80.2; p = 0.006), as was blood plasma viral load (adj OR, 19.3 per factor 10 increase; p < 0.001) and age (adj OR, 1.16 per 1 year older; p = 0.001). Antiviral treatment status, absolute CD4 and CD8 count, clinical stage, treatment centre, ethnicity, and risk factor were not independent predictors. No subject with undetectable blood viral load had detectable seminal HIV RNA. CONCLUSION: Asymptomatic urethritis is independently associated with seminal HIV RNA shedding.

Adult↗
PubMed1999

Poor reduction of HIV-1 RNA titres in nucleoside reverse transcriptase inhibitor experienced patients treated with indinavir combination therapy.

OBJECTIVES: The long term effectiveness of combination therapy at reducing viral loads in seminal fluid and blood plasma obtained from HIV-1 infected men who had undergone previous antiretroviral therapy was assessed. METHODS: Samples of semen and blood were obtained from a cohort of 12 nucleoside reverse transcriptase inhibitor experienced men before and during 25-68 weeks of combination therapy, which included the protease inhibitor indinavir. HIV-1 RNA titres present in the cell free blood and seminal plasma samples were determined using the nucleic acid sequence based amplification (NASBA)/Nuclisens assay system. RESULTS: Viral RNA was detected in 9/12 and 7/12 baseline blood plasma and seminal plasma samples, with median viral titres of 10(4.81) and 10(4.56) per ml, respectively. By the end of the study period the detection rates of HIV RNA in the blood and seminal plasma samples were 5/12 and 2/12, respectively, with the median viral titres below the assay cut off level for both sample types. Of the nine patients who had detectable viral RNA in the baseline sample, only three cleared virus from both compartments by the end of the study. CONCLUSIONS: These data show that stable reduction of blood and seminal fluid viral titres is not achievable in a significant proportion of nucleoside reverse transcriptase inhibitor experienced men.

Drug Therapy, Combination↗
PubMed1999

Hepatic dysfunction in a population of antibody-deficient patients: prevalence, aetiology and outcome of PCR screening for hepatitis C and G viruses.

BACKGROUND AND OBJECTIVES: A group of 40 antibody-deficient patients receiving regular infusions of intravenous immunoglobulin underwent close monitoring in an attempt to identify hepatic dysfunction. The continuing risk of hepatitis virus transmission, especially hepatitis C virus via immunoglobulin products prompted this policy. We report our findings. METHODS: Screening included measurement of transaminase levels at each infusion. The patients were also tested for evidence of infection with hepatitis viruses B, C and G. RESULTS: Abnormal liver function tests were identified in 6 cases. However, a blood-borne viral aetiology was not found in any of these cases. Additional investigation allowed an alternative aetiology to be identified in most cases. One patient found to be positive for hepatitis G virus (HGV)-RNA by reverse transcriptase-polymerase chain reaction has no evidence to date of clinical problems as a result. INTERPRETATION: The results are reassuring in that definite iatrogenic hepatitis virus transmission has not been found in this cohort, despite long-term treatment with a wide range of immunoglobulin products. The source of infection of the single patient infected with HGV remains as uncertain as the pathogenic potential of this virus. However, as long as the risk of immunoglobulin-associated viral transmission continues, a strict monitoring programme such as ours should continue to facilitate prompt detection of cases with abnormal liver function. Liver dysfunction in this group requires full investigation and we cannot exclude infection with hitherto unidentified blood-borne viruses.

Adolescent↗
PubMed1999

Prevalence of long-term BK and JC excretion in HIV-infected adults and lack of correlation with serological markers.

The natural history of polyomavirus infection, and sensitivity of diagnostic assays remain unclear. A stratified group of 94 human immunodeficiency virus (HIV)-infected patients was studied for both virological and serological markers of active infection with both JC virus and BK virus. JC DNA was detected in the urine of 18 of 81 (22%) patients and BK DNA in 30 (37%) patients. Whilst patients with a low CD(4) cell count (P =.009), CD(4)/CD(8) ratio (P =.031) and beta2M concentration (P =.042) were significantly more likely to be excreting BK, JC excretion did not correlate with any of the immunological markers measured. Furthermore, when all the immunological factors were taken into account, there was no association between either BK or JC excretion and age of the patient (P =.149 for BK, P = 0.891 for JC). BK IgM antibody was detected in only 3 of 30 (10%) BK excretors. JC IgM was detected in 5 of 18 (27. 7%) JC excretors but also in 11 of 63 (17.5%) patients without demonstrable JC excretion. Therefore IgM was a very poor indicator of viruria. One year follow-up on a subset of patients showed that both DNA detection in urine and IgM antibody remain stable over many months despite falling CD(4) cell counts, and would indicate that events leading to enhanced viral production probably occur early after HIV infection. Replication of JC virus in the brain leading to the onset of progressive multifocal leukoencephalopathy (PML) could not be predicted using any of the markers studied.

Adult↗
PubMed1999

Analysis of hepatitis B virus quasispecies changes during emergence and reversion of lamivudine resistance in liver transplantation.

This report describes nucleotide sequence analysis of part of the polymerase gene of hepatitis B virus (HBV) during the development of lamivudine-resistant HBV in five patients who received lamivudine treatment in conjunction with liver transplantation. Samples from patients were analysed before, during and after drug treatment in conjunction with serum HBV quantification by PCR. Lamivudine resistance was found to be associated with L526M and M550V changes in two patients and M550I change in three patients. Other changes associated with lamivudine resistance in some patients were V509I, A546V, S565A and A568T. The effects on HBV surface antigen are also described. Some patients were subsequently treated with famciclovir and/or ganciclovir with variable outcomes. In two out of three patients who stopped lamivudine treatment, reversion (partial or complete) to wild-type virus was observed after about 5 months. In contrast, a complex mixture of mutant viruses emerged in a third patient who stopped lamivudine treatment.

Antiviral Agents↗
PubMed1998

Investigation of vesicular rashes for HSV and VZV by PCR.

Vesicular fluid from rashes of 132 patients was tested by a multiplex PCR shown to be specific for herpes simplex virus (HSV) type 1 and 2, and varicella zoster virus (VZV) genomic DNA. The results were compared with those obtained by examination by electron microscopy and virus isolation by cell culture. The PCR did not differentiate between HSV 1 and 2. By PCR, 64 HSV infections and 53 VZV infections were identified, with presumed 100% sensitivity and specificity. Fifteen specimens tested negative by PCR, electron microscopy, and virus isolation for herpes viruses. The sensitivities of virus isolation and electron microscopy for detection of herpes simplex virus were 56% and 80%. For varicella zoster virus, the sensitivities of virus isolation and electron microscopy were 47% and 60%. These data illustrate the advantage of rapid PCR diagnosis of herpes simplex virus and varicella zoster virus in vesicle fluids.

Adolescent↗
PubMed1998

GBV-C/HGV coinfection in HIV-1-positive men: frequent detection of viral RNA in blood plasma but absence from seminal fluid plasma.

Sequential paired samples of blood and seminal fluid were obtained from a cohort of 54 HIV-1-infected homosexual males. The prevalence of GBV-C/HGV RNA in the cell-free fractions of some of these patients was determined using reverse-transcription polymerase chain reaction (RT-PCR). To assess the effects of HIV-1 and HCV infection upon GBV-C/HGV RNA status, blood CD4 cell counts, HCV RNA status, and HIV-1 proviral DNA and viral RNA titres were also determined. GBV-C/HGV RNA was detected in 8/30 (27%) of the blood plasma samples obtained at the start of the study, and was present at a frequency of 14/64 (22%) in all the blood plasma samples tested. By contrast, GBV-C/HGV RNA was not detected in the 26 seminal fluid samples obtained at the start of the study, including 8 samples obtained from patients for which GBV-C/HGV RNA was detected in the corresponding blood sample. Of the samples tested for the presence of both GBV-C/HGV and HCV RNA, there was no evidence of coinfection. Although GBV-C/HGV RNA detection rates were significantly higher in individuals with blood CD4 cell counts greater than 200 cells per microlitre, there were no significant differences in the median blood CD4 cell counts or HIV-1 proviral DNA or viral RNA titres observed between the GBV-C/HGV-positive and -negative individuals. The failure to detect GBV-C/HGV RNA in seminal fluid samples obtained from this cohort would suggest that further studies need to be carried out to determine the roles of sexual transmission and of seminal fluid in GBV-C/HGV infection.

CD4 Lymphocyte Count↗
PubMed1998

A multiplex PCR assay for the simultaneous detection of human herpesvirus 6 and human herpesvirus 7, with typing of HHV-6 by enzyme cleavage of PCR products.

A multiplex polymerase chain reaction (PCR) method was developed for the simultaneous detection of human herpesviruses 6 and 7 (HHV-6; HHV-7) in clinical samples, using primers which amplify a section of the HHV-6 U67 gene and the HHV-7 homologue of the HHV-6 U42 gene. Comparison of the multiplex assay with the respective single PCR assays, using cloned HHV-6 and HHV-7 sequences as targets for amplification, showed equivalent sensitivity and specificity for the assays. To demonstrate the use of multiplex PCR for the analysis of clinical samples, serum and saliva from infants were analysed using this technique. The results showed that a clear distinction can be made between the amplicons of HHV-6 and HHV-7, without loss of sensitivity or specificity. There was complete concordance between the respective single PCR assays, and the multiplex PCR. HHV-6 amplicons derived from the multiplex PCR analysis were typed by differential AvaII restriction endonuclease digestion, in which HHV-6 variant A amplicons are cleaved but those of variant B remain undigested. These results were compared to HHV-6 variant typing by an established method, the results of which showed complete concordance between assays. It is proposed that this multiplex assay, where HHV-6 positive samples may be typed directly from the reaction products, is an efficient and cost-effective approach to the analysis of large numbers of samples to determine the epidemiological importance of HHV-6 and HHV-7.

Child↗