Labour care of women with HIV infection. Article did not highlight current guidelines.
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Female↗
Biomedical subjects
G P Taylor
Publications and source records attributed to G P Taylor.
Role of maternal humoral immunity in vertical transmission of HIV-1 subtype E in Thailand.
The significance of the maternal humoral immune response in relation to vertical transmission of HIV-1 was investigated in 123 mothers infected with subtype E from Thailand. Antibody binding titers to HIV-1 env domains (monomeric gp120, the CD4/gp120 binding site [BS], V3 loop, and gp41) and antibody-mediated neutralization of primary and T-cell line-adapted (TCLA) subtypes B and E HIV-1 isolates were investigated. No correlation between maternal anti HIV-1 antibodies at delivery and vertical transmission of HIV-1 subtype E was found. However, a trend to higher titer antibody-mediated cross-neutralization of a heterologous subtype B TCLA isolate, HIV-1MN, was observed in nontransmitting mothers postpartum. The HIV-1-specific antibody titers in these infected mothers increased significantly from delivery to 6 months postpartum (p < .05), but this was only partially attributable to hemodilution and an additional factor or factors appear to affect humoral immunity to HIV-1 during late pregnancy.
Adult↗
Low prevalence of HTLV-I/II infection among HIV-1-infected injecting drug users in Russia.
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HIV Infections↗
HLA alleles determine human T-lymphotropic virus-I (HTLV-I) proviral load and the risk of HTLV-I-associated myelopathy.
The risk of disease associated with persistent virus infections such as HIV-I, hepatitis B and C, and human T-lymphotropic virus-I (HTLV-I) is strongly determined by the virus load. However, it is not known whether a persistent class I HLA-restricted antiviral cytotoxic T lymphocyte (CTL) response reduces viral load and is therefore beneficial or causes tissue damage and contributes to disease pathogenesis. HTLV-I-associated myelopathy (HAM/TSP) patients have a high virus load compared with asymptomatic HTLV-I carriers. We hypothesized that HLA alleles control HTLV-I provirus load and thus influence susceptibility to HAM/TSP. Here we show that, after infection with HTLV-I, the class I allele HLA-A*02 halves the odds of HAM/TSP (P < 0.0001), preventing 28% of potential cases of HAM/TSP. Furthermore, HLA-A*02(+) healthy HTLV-I carriers have a proviral load one-third that (P = 0.014) of HLA-A*02(-) HTLV-I carriers. An association of HLA-DRB1*0101 with disease susceptibility also was identified, which doubled the odds of HAM/TSP in the absence of the protective effect of HLA-A*02. These data have implications for other persistent virus infections in which virus load is associated with prognosis and imply that an efficient antiviral CTL response can reduce virus load and so prevent disease in persistent virus infections.
Alleles↗
Clinical outcomes of acute myocarditis in childhood.
OBJECTIVE: To describe clinical outcomes of a paediatric population with histologically confirmed lymphocytic myocarditis. DESIGN: A retrospective review between November 1984 and February 1998. SETTING: A major paediatric tertiary care hospital. PATIENTS: 36 patients with histologically confirmed lymphocytic myocarditis. MAIN OUTCOME MEASURES: Survival, cardiac transplantation, recovery of ventricular function, and persistence of dysrhythmias. RESULTS: Freedom from death or cardiac transplantation was 86% at one month and 79% after two years. Five deaths occurred within 72 hours of admission, and one late death at 1.9 years. Extracorporeal membrane oxygenation support was used in four patients, and three patients underwent heart replacement. 34 patients were treated with intravenous corticosteroids. In the survivor/non-cardiac transplantation group (n = 29), the median follow up was 19 months (range 1.2-131.6 months), and the median period for recovery of a left ventricular ejection fraction to > 55% was 2.8 months (range 0-28 months). The mean (SD) final left ventricular ejection and shortening fractions were 66 (9)% and 34 (8)%, respectively. Two patients had residual ventricular dysfunction. No patient required antiarrhythmic treatment. All survivors reported no cardiac symptoms or restrictions in physical activity. CONCLUSIONS: Our experience documents good outcomes in paediatric patients presenting with acute heart failure secondary to acute lymphocytic myocarditis treated with immunosuppression. Excellent survival and recovery of ventricular function, with the absence of significant arrhythmias, continued cardiac medications, or restrictions in physical activity were the normal outcomes.
Acute Disease↗
British HIV Association guidelines for prescribing antiretroviral therapy in pregnancy (1998).
The aim of antiretroviral therapy in pregnancy is to deliver a healthy uninfected child to a healthy mother, without prejudicing the future treatment opportunities of the mother. The use of zidovudine monotherapy rapidly became standard practice once it had been shown to reduce by 67% mother to child transmission in women with CD4+ lymphocyte counts above 200 x 10(6)/l. High rates of transmission are seen when maternal disease is advanced (high viral load, low CD4+ lymphocyte counts) despite zidovudine. In these women highly active antiretroviral therapy gives the best prospect for prolonged health and it is anticipated that reducing plasma viral load below the limits of detection will further reduce transmission rates. However, safety data for antiretroviral therapy in pregnancy are limited and each additional treatment exposes a significant proportion of uninfected infants to potential long term hazards. Where maternal therapy is not indicated and the sole objective of treatment is to reduce mother to child transmission, recent data suggest that short course zidovudine (especially in conjunction with prelabour caesarean section) is a reasonable option. This may minimise the emergence of viruses with reduced sensitivity to zidovudine and preserve maternal options for later therapy.
Anti-HIV Agents↗
Cardiac manifestations of congenital fiber-type disproportion myopathy.
Cardiac involvement has not been a reported feature of congenital fiber-type disproportion myopathy. We describe two children, aged 13 years and 1 year, respectively, who presented with serious cardiac symptomatology in conjunction with congenital fiber-type disproportion. One child developed dilated cardiomyopathy and medically intractable congestive heart failure necessitating cardiac transplantation at the age of 13 years. The second (unrelated) child developed atrial fibrillation with rapid atrioventricular conduction requiring treatment with digoxin. Skeletal muscle biopsy findings in both children showed congenital fiber-type disproportion with no evidence of a structural, dystrophic, or metabolic myopathy. Adenosine triphosphatase (ATPase) reacted sections showed type I hypotrophy with a predominance of type I fibers, confirmed by histogram analysis. Examination of the heart from patient 1 at the time of transplantation confirmed dilated cardiomyopathy with hypertrophic myocardiocytes. Although cardiomyopathy is commonly associated with other childhood myopathies, to our knowledge it has not been a feature in reported cases of congenital fiber-type disproportion. We recommend close cardiac assessment, with annual electrocardiograms, of children with congenital fiber-type disproportion.
Biopsy↗
Enhanced MDR1 gene expression in human T-cell leukemia virus-I-infected patients offers new prospects for therapy.
Overexpression of P-glycoprotein (P-gp), the protein product of the multidrug resistance gene (MDR1), confers a drug resistant phenotype on cells. This phenotype is reminiscent of human T-cell leukemia virus (HTLV)-transformed leukemic cells, for which no consistently effective chemotherapeutic regime has been found. The presence of an active multiple drug resistance (MDR) phenotype in freshly isolated peripheral blood mononuclear cells (PBMC) from HTLV-I-infected subjects was investigated. Significant P-gp-mediated efflux activity and enhanced MDR1 mRNA expression was observed in nine of 10 HTLV-infected subjects. The development of MDR phenotypes was found to be independent of disease type or status with significant MDR activities being observed in adult T-cell leukemia (ATL), HTLV-associated myelopathy (HAM)/tropical spastic paraparesis (TSP), and asymptomatic HTLV-infected individuals. P-gp-mediated drug efflux was also found to be restricted to CD3+ T-cell populations. Furthermore, we show the novel finding that the MDR1 gene promoter is transcriptionally activated by the HTLV-I tax protein, suggesting a molecular basis for the development of drug resistance in HTLV-I infections. These observations open up the possibility of new chemotherapeutic approaches to HTLV-associated diseases through the use of P-gp inhibitors.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Review of uptake of interventions to reduce mother to child transmission of HIV by women aware of their HIV status.
OBJECTIVES: To examine the change in uptake of interventions to reduce transmission of HIV from mothers to infants from January 1994 to July 1997. DESIGN: Review of mother-infant pairs who presented for infant diagnosis of HIV infection. SETTING: Central London hospital with facilities for diagnosis of infant HIV infection. SUBJECTS: 57 consecutive mother-infant pairs, mainly from central London but also referred from surrounding hospitals. INTERVENTIONS: Data were collected on mother's country of origin; CD4 count at delivery; plasma HIV RNA copies/ml; mode of delivery; antiretroviral therapy; infant feeding; and HIV infection in infants. MAIN OUTCOME MEASURES: HIV infection of infants. RESULTS: The vertical transmission rate was 12% (7 pairs; 95% confidence interval 3% to 22%). All mothers chose not to breast feed. The caesarean section rate was 53% (30/57). Antiretroviral therapy was taken by 68.5% (39/57) of mother-infant pairs. With antiretroviral therapy or caesarean section, or both, transmission occurred in 6% (0% to 13%) of pairs (3/50). During the 24 months of 1994 and 1995, 21% (4/19) of infants were infected with HIV; 7.9% (3/38) were infected over the 19 months January 1996 to July 1997. The caesarean section rate did not change over these periods. Use of antiretroviral therapy increased from 31.5% (6/19) to 86.8% (33/38) (P < 0.0001). CONCLUSION: Women with a diagnosis of HIV infection acted to reduce the risk of transmission to their infants. Uptake of antiretroviral therapy increased significantly over time, and the caesarean section rate was persistently high.
Africa↗
Renal-cell carcinoma in children: a different disorder from its adult counterpart?
BACKGROUND: Renal-cell carcinoma (RCC) is a rare tumor in children. To address whether RCC in children differs from its adult counterpart, we report a series of 16 children with RCC (5 boys, 11 girls, mean age 9.6 years, range 3-19 years) presenting between 1979 and 1996 at three pediatric centers. PROCEDURE: Pathology showed papillary RCC in five patients (31%). Nonpapillary tumors were present in 11 (69%), of which nine were clear-cell type (56%), one was chromophobe-cell type (6%), and one was granular-cell type (6%). Cytogenetic studies were performed on four. RESULTS: In two tumors, normal karyotypes (45,XX or 45,XY) were found. In another, there were translocations: t(X;1), t(X;2) and t(6;14). In the fourth, analysis revealed 46,XX/46,X,t(X;17)(p11.2;q25),t(1;12). Several features in this series differ from those reported in adults. In adults, RCC is more frequent in males, is usually nonpapillary, and is characterized cytogenetically by deletions or rearrangements in the short arm of chromosome 3. In contrast, in our series there was no male predominance and a higher proportion of papillary tumors. In addition, two of four cytogenetically analyzed tumors had translocations involving the X chromosome. Translocations involving the Xp11.2 locus have been infrequently reported in both adults and children with papillary RCC. CONCLUSIONS: The higher frequency of papillary histology and the presence of translocations involving Xp.11.2 in two cases raise the possibility of a unique subtype of RCC in children.
Adolescent↗
Extraction of RNA from single frozen sections.
The sensitivity of the reverse transcriptase-polymerase chain reaction (RT-PCR) makes it ideally suited for the detection of changes in gene expression. Unfortunately, traditional methods for RNA isolation require time-consuming procedures that are not appropriate for small samples, such as individual frozen sections. This report describes a new technique that permits the rapid extraction of RNA from individual frozen histological sections. RNA is extracted by incubating a frozen section in an RT-PCR compatible buffer solution containing RNase inhibitor and dithiothreitol. RNA isolated from frozen sections is stable at room temperature for up to 3 h under the conditions described. Alternatively, extracts can be frozen for later use. When maintained in a dry state at room temperature, RNA in sections remained stable for 2 weeks. Histological, immunohistochemical, or in situ analyses can be carried out with sections that are immediately adjacent to those used for extracting RNA. The simplicity and economy of this procedure may foster the development of prognostic screens that can be performed in parallel with traditional histopathological analysis.
Buffers↗
Quantification of proviral DNA load in human T-cell leukaemia virus type I infections.
A nested PCR was designed using primers from the pol and tax genes of human T-cell leukaemia virus type I (HTLV-I). The assay reliably detected a single copy of HTLV-I proviral genome in DNA from 1 x 10(5) Peripheral blood mononuclear cells (PBMCs). Using serial dilutions of sample DNA, the assay was applied prospectively to study proviral load in patients with HTLV-associated disease and carriers. The median proviral load expressed as number of copies/100 PBMCs was found to be 14.0 copies in patients with HAM and 1.55 copies in initially asymptomatic carriers. The assay was used to test for low proviral load in subjects who may have HTLV-I infection, and to monitor response to therapy.
Cell Line↗
Overview of matrix metalloproteinase expression in cultured human cells.
The matrix metalloproteinases (MMP) have been implicated in tumor invasion and metastasis both by immunohistochemical studies and from the observation that specific metalloproteinase inhibitors block tumor invasion and metastasis. Oligonucleotide primers for thirteen MMPs (MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-10, MMP-11, MMP-12, MMP-13, MMP-14, MMP-15, MMP-16) were optimized for use in RT-PCR. A semi-quantitative RT-PCR assay was used to determine the pattern of MMP mRNA expression in 84 normal and transformed or carcinogen transformed human cell lines and strains derived from different tissues. The results demonstrate one or more cell lines which express thirteen members of the MMP family. In addition, various oncogene transfected human fibroblast cell strains were analyzed for MMP expression. We confirm that over-expression of the H-ras oncoprotein correlates with up-regulation of MMP-9 and demonstrate that over-expression of v-sis also up-regulates MMP-9. A cell line immortalized following myc expression was found to up-regulate MMP-7, MMP-11 and MMP-13. Inappropriate expression of several MMP mRNAs was detected in breast, prostate, bone, colon and oral tumor derived cell lines. Identification of at least one cell line expressing each of thirteen MMPs and the observation of oncogene induced expression of several MMPs should facilitate analysis of the transcriptional mechanisms controlling each MMP.
Cell Line↗
Intrapartum mucosal exposure to human immunodeficiency virus type 1 (HIV-1) of infants born to HIV-1-infected mothers correlates with maternal plasma virus burden.
The majority of vertical infections with human immunodeficiency virus type 1 (HIV-1) occur at or near delivery, strongly suggesting a mucosal route of transmission. The frequency and level of intrapartum mucosal exposure to HIV-1 of 22 infants born to infected mothers was investigated. Maternal plasma HIV-1 RNA and CD4 cell count were measured at delivery. Infant oropharyngeal aspirates obtained at birth were examined for HIV-1 RNA by reverse transcription-polymerase chain reaction and qualitative nucleic acid sequence-based amplification. Nine infants (41%) had detectable levels of HIV-1 RNA, 3 of which were quantifiable (mean, 3000 copies/mL). This mucosal exposure to HIV-1 during delivery did not lead to infection of any infant. Cesarian delivery did not reduce mucosal exposure to HIV-1. Mucosal exposure did not correlate with maternal CD4 cell count but did correlate with maternal plasma virus load and was reduced by antiretroviral therapy.
Adult↗
Pathogenesis and treatment of HTLV-I associated myelopathy.
That HTLV-I is not a latent infection is indicated by the detection of mRNA in the peripheral blood and CNS of patients with HTLV-I infection and by the persisting humoral and cellular immune responses. Indeed the frequency of anti-HTLV CTL is extremely high. The reduction in anti-TAX CTL frequency following reduction in proviral load suggests that removal of viral antigen may result in a reduced inflammatory response at least in peripheral blood and although the clinical data should be interpreted with caution, perhaps in the CNS. Patients with more advanced disease, and possibly fixed deficits may not benefit from either anti-inflammatory or antiretroviral treatment. The patients with most to gain are those with least deficit in whom early diagnosis and treatment will depend on raising awareness of HTLV-I beyond the neurological community. Many patients with HAM first present to a urologist or gynaecologist with bladder dysfunction or may have been seen in the genitourinary clinical with impotence or positive treponemal serology, which in the older patient is often the result of childhood infection with Treponema pallidum pertenue. Investigation of these patients should include HTLV-I serology and further investigation of HTLV-I positive patients should include proviral load measurements as well as markers of inflammation. Treatments whether antiviral or anti-inflammatory should be assessed for their effect on both as well as a clinical response.
Adolescent↗
Patterns of immunodominance in HIV-1-specific cytotoxic T lymphocyte responses in two human histocompatibility leukocyte antigens (HLA)-identical siblings with HLA-A*0201 are influenced by epitope mutation.
Primary human immunodeficiency virus (HIV) infection is controlled principally by HIV-specific cytotoxic T lymphocytes (CTL) to a steady-state level of virus load, which strongly influences the ultimate rate of progression to disease. Epitope selection by CTL may be an important determinant of the degree of immune control over the virus. This report describes the CTL responses of two HLA-identical hemophiliac brothers who were exposed to identical batches of Factor VIII and became seropositive within 10 wk of one another. Both have HLA-A*0201. The CTL responses of the two siblings were very dissimilar, one donor making strong responses to two epitopes within p17 Gag (HLA-A*0201-restricted SLYNTVATL and HLA-A3-restricted RLRPGGKKK). The sibling responded to neither epitope, but made strong responses to two epitopes presented by HLA-B7. This was not the result of differences in presentation of the epitopes. However, mutations in both immunodominant epitopes of the p17 Gag responder were seen in proviral sequences of the nonresponder. We then documented the CTL responses to two HLA-A*0201-restricted epitopes, in Gag (SLYNTVATL) and Pol (ILKEPVHGV) in 22 other HIV-infected donors with HLA-A*0201. The majority (71%) generated responses to the Gag epitope. In the 29% of donors failing to respond to the Gag epitope in standard assays, there was evidence of low frequency memory CTL responses using peptide stimulation of PBMC, and most of these donors also showed mutations in or around the Gag epitope. We concluded that HLA class I genotype determines epitope selection initially but that mutation in immunodominant epitopes can profoundly alter the pattern of CTL response.
Amino Acid Sequence↗
Prognostic factors in the treatment of lymphatic malformations.
OBJECTIVE: To find factors that may influence the treatment outcomes of lymphatic malformations of the head and neck in children. DESIGN: Charts of patients treated surgically for lymphatic malformations of the head and neck between 1988 and 1996 at our tertiary care children's hospital were reviewed retrospectively. Outcomes were correlated with age at presentation, associated symptoms, anatomical site (s) of involvement, extent of disease, length of time between first symptoms and surgery, completeness of removal, and histologic pattern. PATIENTS: Of 85 children treated, 74 underwent primary surgical excision at our hospital. Follow-up ranged from 6 months to 8 years, with a mean of 3 years. RESULTS: The overall recurrence rate, judged by functional or cosmetic deformity, was 22%. Two neonates died of the disease. Factors associated with a better prognosis were a single anatomical site of involvement; location in the neck, even if involving 2 sites; and the impression of completeness of resection at the time of surgery. Findings associated with a higher recurrence rate included younger age (especially neonates) and the presence of associated symptoms (ie, infection, dyspnea, dysphagia, and hemorrhage). The histologic pattern and the length of time from diagnosis to treatment were not significantly associated with the prognosis. CONCLUSIONS: We recommend aggressive, timely surgical excision for lymphatic malformations of the head and neck. The timing of surgery should be based on the child's functional and cosmetic deformity at the time of presentation and on the likelihood of complete excision, weighed against the morbidity associated with surgical excision.
Adolescent↗
No evidence of antibody to human foamy virus in widespread human populations.
The first human foamy virus (HFV) to be described was isolated from nasopharyngeal carcinoma tissue from a Kenyan patient. Early seroepidemiology concluded that there was a significant infection rate, particularly among Africans. Awareness of foamy viruses as potential vectors has stimulated interest in the natural seroprevalence of HFV infection. We, therefore, investigated the prevalence of HFV infection in more than 5000 human sera collected from diverse populations. To maximize the chances of including the major antigenic epitopes, recombinant proteins derived from the HFV gag and env genes divided into three (the 5' amino terminal, the 3' carboxy terminal, and an internal overlapping region) were used as antigens in an ELISA. In contrast to most other seroepidemiological investigations of HFV infection, highly reactive sera identified by ELISA were subjected to further analysis by additional serological assays and, where PBMCs were available, PCR. None of the serum samples were confirmed as positive. It is worth noting that with our ELISA, the highest level of serum reactivity to HFV was found in subjects from Pacific islands (17%), and in Central Africa (34% in Malawi), areas previously cited as having a high level of HFV infection. Taken together with sequence analysis endorsing the phylogenetic closeness of HFV to SFV-6/7, these data strongly suggest that HFV is not naturally found in the human population.
Blotting, Western↗