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Biomedical subjects

L Guay

Publications and source records attributed to L Guay.

18 recordsLinked to original sources
PubMed2001

The relationship of maternal and child HIV infection to security of attachment among Ugandan infants.

This study was designed to examine the relationship of maternal and child human immunodeficiency virus (HIV) infection to the security of attachment of Ugandan infants. The attachment patterns of two groups of Ugandan mother-infant pairs: 35 HIV-positive mothers and their infants and 25 HIV-negative mothers and their infants were compared. We tested the hypothesis that infants of HIV-positive mothers would demonstrate less secure attachment as measured by the Waters Attachment Q-set than infants of HIV-negative mothers. No differences were found in the security of attachment of infants of HIV-positive versus HIV-negative mothers. Infants of HIV-positive mothers with Acquired Immunodeficiency Syndrome (AIDS) were less securely attached than infants of mothers without AIDS. These findings underscore the relationship of infant security of attachment to maternal HIV infection in the presence of AIDS-related symptoms but not to asymptomatic maternal HIV infection.

Adult↗
PubMed2000

Identification of diverse HIV type 1 subtypes and dual HIV type 1 infection in pregnant Ugandan women.

Vertical (mother-to-child) transmission accounts for the majority of pediatric HIV-1 infections. Many factors are involved in vertical transmission, however it is not clear which factors are most important for determining whether a mother will transmit HIV-1 to her infant. It has been suggested that HIV-1 subtype may influence vertical transmission and that subtype D viruses may be less likely to be transmitted in this setting. We analyzed HIV-1 gp120 V3 region sequences from the plasma of 20 pregnant Ugandan women of known transmission status who did not receive antiretroviral prophylaxis. V3 regions were cloned, sequenced, and subtyped by phylogenetic analysis. Among 11 women who transmitted HIV-1 to their infants, we detected subtypes A, C, D, and G. Two of the transmitters had dual infection with subtypes A and D. In addition, a third was infected with two distinct strains of subtype G viruses. HIV-1 subtype A and D viruses were found in 9 women who did not transmit the virus to their infants. This study reveals that pregnant Ugandan women harbor diverse HIV-1 subtypes, including women who transmit HIV-1 to their infants. Transmission of HIV-1 with subtype D V3 regions was confirmed in 4 of the 11 transmitters, including 2 who had dual infection with subtype A and D HIV-1.

Amino Acid Sequence↗
PubMed1999

Cost effectiveness of single-dose nevirapine regimen for mothers and babies to decrease vertical HIV-1 transmission in sub-Saharan Africa.

BACKGROUND: Identification of economical interventions to decrease HIV-1 transmission to children is an urgent public-health priority in sub-Saharan Africa. We assessed the cost effectiveness of the HIVNET 012 nevirapine regimen. METHODS: We assessed cost effectiveness in a hypothetical cohort of 20,000 pregnant women in sub-Saharan Africa. Our main outcome measures were programme cost, paediatric HIV-1 cases averted, cost per case averted, and cost per disability-adjusted life-year (DALY). We compared HIVNET 012 with other short-course antiretroviral regimens. We also compared two implementation strategies: counselling and HIV-1 testing before treatment (targeted treatment), or nevirapine for all pregnant women (universal treatment, no counselling and testing). We did univariate and multivariate sensitivity analyses. FINDINGS: For universal treatment with 30% HIV-1 seroprevalence, the HIVNET 012 regimen would avert 603 cases of HIV-1 in babies, cost US$83,333, and generate 15,862 DALYs. The associated cost-effectiveness ratios were $138 per case averted or $5.25 per DALY. At 15% seroprevalence, the universal treatment option would cost $83,333 and avert 302 cases at $276 per case averted or $10.51 per DALY. For targeted treatment at 30% seroprevalence, HIVNET 012 would cost $141,922 and avert 476 cases at $298 per case averted or $11.29 per DALY. With seroprevalence higher than 3.0% for universal and 4.5% for targeted treatment, the HIVNET 012 regimen was likely to be as cost effective as other public-health interventions. The cost effectiveness of HIVNET 012 was robust under a wide range of parameters in the sensitivity analysis. INTERPRETATION: The HIVNET 012 regimen can be highly cost-effective in high seroprevalence settings. In lower seroprevalence areas, when multidose regimens are not cost effective, nevirapine therapy could have a major public-health impact at a reasonable cost.

Africa South of the Sahara↗
PubMed1999

A new generation of polyurethane vascular prostheses: rara avis or ignis fatuus?

Three polyurethane (PU) vascular grafts with novel designs were investigated and compared in terms of the microporous structure, reinforcement technology, polymer chemistry, microphase separation, and mechanical properties. The Corvita graft, composed of a poly(carbonate urethane) polymer, displayed a helically wound filament structure with communicating inter-fiber spaces. The reinforced model contained an external PET mesh impregnated with a protein sealant, and displayed good microphase separation, the highest Young's modulus in the longitudinal direction, and the second highest in the radial direction. The Thoratec graft was made of a polyetherurethaneurea with an average micropore size of 15 microns. Silicone was observed on both surfaces of the graft. The Thoratec device displayed a low degree of hydrogen-bonding among the urethane groups and had no well-organized hard-segment domains. Its mechanical strength was superior to that of the Pulse-Tec graft. A solid PU layer underneath the luminal surface precluded any communication between the luminal and adventitial sides. The Pulse-Tec prosthesis was composed of polyetherurethane, with an average micropore size of 28 microns. It offered the highest radial compliance, a high degree of hydrogen-bonding, a narrow molecular weight distribution, and a certain degree of microphase separation. Its tensile strength and hysteresis loss were inferior to those of the other two grafts.

Animals↗
PubMed1999

Neurodevelopmental outcomes of Ugandan infants with HIV infection: an application of growth curve analysis.

Neurodevelopmental outcomes of human immunodeficiency virus Type 1 (HIV-1)-infected infants of non-drug-using mothers were assessed in a controlled, prospective study from birth to 24 months with 3 groups: 61 infants of HIV-infected mothers, 234 uninfected infants of HIV-infected mothers (seroreverters), and 115 uninfected infants of uninfected mothers. Compared with seroreverters and uninfected infants, HIV-infected infants demonstrated lower mental and motor development on the Bayley Scales and greater deceleration in their rate of motor development. HIV-infected infants with abnormal neurologic exams had lower motor and mental test scores and lower rates of motor Bayley Scales scores than their HIV-infected counterparts with normal neurologic exams. Contrary to prediction, no group differences in mean performance or growth rates were found on visual information processing on the Fagan Test of Infant Intelligence.

AIDS Dementia Complex↗
PubMed1999

Human immunodeficiency virus status and delayed-type hypersensitivity skin testing in Ugandan children.

BACKGROUND: In previous studies, delayed-type hypersensitivity (DTH) skin testing has been shown to be affected by several factors including nutritional status, intercurrent infection, host immune status, and previous exposure to the antigen being used. OBJECTIVE: To determine the effect of human immunodeficiency virus type 1 (HIV-1) status on DTH skin testing in a cohort of HIV-1-infected and noninfected Ugandan children followed prospectively from birth. DESIGN: Nested case-control study. SETTING: Primary care clinic serving study participants at Mulago Hospital, Makerere University, Kampala, Uganda. PARTICIPANTS: Thirty HIV-1-infected children and 30 age-matched, HIV-1-noninfected children. METHODS: After completion of history and physical, each child underwent Mantoux skin testing with both Candida and purified protein derivative (PPD). Results of skin testing were read in 48 to 72 hours. Complete chart reviews were performed on all children. CD4 lymphocyte counts were obtained on all HIV-1-infected children at the time the skin testing was read. RESULTS: The average age of participants was 67 months (range, 51-92 months). HIV-1-infected children (mean CD4 lymphocyte count, 1069 mL-1; range, 86-3378 mL-1), compared with noninfected, age-matched peers, developed significantly smaller PPD reaction size (mean, 1.18 mm +/- 4.3 vs 3.6 mm +/- 7.6, respectively). Candida responses were not different between the two groups of children. Among HIV-1-infected children, there was a larger Candida reaction size in children who had recently received chloroquine treatment. There was no significant correlation between Candida reactivity and PPD reactivity, progressive HIV-1 disease, or CD4 lymphocyte count. The six children diagnosed clinically with active tuberculosis had lower absolute CD4 lymphocyte counts than children without tuberculosis. Lack of reaction to PPD was associated with lower CD4 lymphocyte counts and progressive HIV-1 disease. CONCLUSIONS: In HIV-1-infected Ugandan children, DTH skin testing was influenced by the choice of antigen selected, HIV-1 infection, and recent treatment with chloroquine. Based on these findings, we believe that further prospective, longitudinal investigation into the role of chloroquine in HIV-1-infected children is needed. We emphasize the limitations of DTH skin testing in HIV-infected children as an adjunct in the diagnosis of active tuberculosis.

Antigens, Fungal↗
PubMed1997

Neurodevelopmental outcomes of Ugandan infants with human immunodeficiency virus type 1 infection.

BACKGROUND: The neurodevelopmental outcomes of human immunodeficiency virus type 1 (HIV-1)-infected Ugandan infants of nondrug-using mothers were studied using controlled, prospective methodology. METHOD: The sample of 436 full-term infants included 79 HIV-infected infants of HIV-1-infected mothers, 241 uninfected infants of HIV-1-infected mothers (seroreverters), and 116 uninfected infants born to HIV-negative mothers. Neurologic status, information processing ability, and motor and mental development were assessed from 6 to 24 months of age. Observations of caretaker-child interaction and home environments were made at 6 and 12 months. All evaluators were blinded to the HIV status of the child and family. RESULTS: Compared with seroreverters and uninfected infants, HIV-infected infants demonstrated greater deficits in motor development and neurologic status, and more frequent and earlier onset of motor and neurologic abnormalities. Compared with controls, HIV-infected infants had more abnormalities in mental development at 6 and 18 months and an earlier onset of abnormalities. By 12 months, 30% of HIV-infected infants demonstrated motor abnormalities and 26% cognitive abnormalities as compared with 11% and 6% among seroreverters and 5% and 6% among seronegative infants. HIV-infected infants (62%) demonstrated a higher probability of developing an abnormal neurologic examination by 12 months, compared with seroreverters (17%) or seronegative infants (15%). Information-processing abilities did not differ as a function of HIV infection. Home environments and infants' interactions with caretakers were similar across groups. CONCLUSION: We conclude that HIV infection results in more frequent and earlier abnormalities in infants' neurologic status and motor development that are not attributable to other biological and environmental risk factors. More frequent mental developmental abnormalities were evident at several ages. However, information-processing abilities, such as recognition memory, may be spared from HIV-related deficits.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Maternal HIV-1 RNA serum levels at delivery and vertical transmission in Uganda.

OBJECTIVE: To evaluate the clinical utility of maternal HIV-1 RNA serum levels at delivery in predicting the rate of HIV-1 vertical transmission. DESIGN AND METHODS: HIV-1 RNA levels were determined by the Roche Amplicor Monitor assay in serum specimens collected at the time of delivery from 94 transmitting and 107 nontransmitting infected mothers and 12 seronegative mothers in Uganda. Nonparametric Wilcoxon-Rank sum tests were used to identify significant differences in medians and RNA level distributions by transmission status. RESULTS: Mean HIV-1 RNA copies/mL for transmitters was 3419 +/- 7489 copies/mL versus 2483 +/- 8954 copies/mL for nontransmitters. There was a significant difference in medians and HIV-1 RNA serum level distributions between transmitting and nontransmitting mothers (p = 0.0039). However, the predictive value for any given HIV-1 RNA level for HIV-1 vertical transmission was poor. CONCLUSION: Maternal HIV-1 RNA serum levels at delivery are significantly higher in transmitting mothers versus nontransmitting mothers, but appear to be of limited value in predicting HIV-1 vertical transmission using the Roche Amplicor Monitor assay in Uganda.

Case-Control Studies↗
PubMed1994

Lack of association between anti-V3 loop antibodies and perinatal transmission of HIV-1 in Kampala, Uganda.

This study evaluated the association between reactivity of maternal antibody to human immunodeficiency virus type 1 (HIV-1) V3 loop peptides and perinatal transmission in Uganda. Plasma from 40 HIV-1-infected mothers (20 transmitting and 20 nontransmitting mothers) and 31 uninfected mothers in Uganda were tested for reactivity and antibody titer to synthetic peptides representing V3 loop sequences from HIV-1 strains MN, SF2, LAI, ZR6, and CM235 and consensus peptides CA, CB, and CD. No significant differences were found between 20 transmitting mothers and 20 nontransmitting mothers in terms of percent reactivity or titer of antibody to any of the V3 loop peptides tested. Use of a multivariable logistic model to adjust for beta-2 microglobulin level as a confounding variable of stage of infection did not help demonstrate an association except possibly for the ZR6 peptide. These data suggest that neither reactivity nor maternal antibody titer to V3 loop peptides are protective against perinatal transmission of HIV-1 in Uganda.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Beta 2-microglobulin, HIV-1 p24 antibody and acid-dissociated HIV-1 p24 antigen levels: predictive markers for vertical transmission of HIV-1 in pregnant Ugandan women.

OBJECTIVES: To evaluate the clinical utility of plasma beta 2-microglobulin (beta 2M) levels, acid-dissociated HIV-1 p24 antigen, and HIV-1 p24-antibody titers in predicting HIV-1 vertical transmission in 227 HIV-1-infected Ugandan pregnant women. DESIGN: Plasma beta 2M levels, acid-dissociated HIV-1 p24-antigen positivity, and HIV-1 p24-antibody titers were determined using commercial enzyme immunoassays (EIA) in a Ugandan cohort of 52 HIV-1-seropositive transmitting mothers, 175 HIV-1-seropositive non-transmitting mothers, and 52 seronegative mothers within 6 weeks prior to delivery. RESULTS: Transmitter mothers had significantly higher plasma concentrations of beta 2M (1.80 +/- 1.13 mg/l) than non-transmitter seropositive mothers (1.32 +/- 0.81 mg/l; P = 0.0013). Similarly, a significantly higher proportion of transmitter mothers had detectable p24 antigen than non-transmitter mothers [six out of 51 (11.8%) versus six out of 173 (3.5%); P = 0.03]. Compared with the vertical transmission rate of 23% in the seropositive group, the positive predictive values of a beta 2M level > 1.5 mg/l or detectable HIV-1 p24 antigen for vertical transmission were 34 and 50%, respectively. Five of six (83.3%) seropositive mothers with both a beta 2M level > 1.5 mg/l and detectable p24 antigenemia transmitted HIV-1 infection to their infants compared with 25 of 124 (20.2%) seropositive mothers with values below the cut-off values for both tests (P = 0.00249). However, beta 2M was not found to be a significant independent predictor of vertical transmission when analyzed in a multivariate model with p24 antigenemia. There was no significant difference in HIV-1 p24-antibody titers in transmitter mothers versus non-transmitter mothers (P = 0.299). CONCLUSION: beta 2M levels and acid-dissociated HIV-1 p24-antigen assays may be used to predict which HIV-1-infected pregnant women are at greatest risk for vertical transmission. However, only the p24-antigen test was independently predictive of vertical transmission and its clinical utility is limited.

Adolescent↗
PubMed1991

Non-isotopic polymerase chain reaction methods for the detection of HIV-1 in Ugandan mothers and infants.

Two non-isotopic polymerase chain reaction (PCR) methods were evaluated by testing blood from 41 HIV-1-seropositive and 16 HIV-1-seronegative Ugandan mothers and 56 of their children (aged 0.5-15.0 months). Amplification of HIV-1 sequences was performed in duplicate using a biotinylated primer pair to the gag region (SK 462-431) and nested primer pairs (JA 17-20) to the pol region of HIV-1. gag sequences were hybridized using a microtiter plate coated with the SK 102 probe followed by colorimetric detection using an avidin-horseradish peroxidase conjugate and tetramethylbenzidine/peroxide substrate. pol sequences were detected on agarose gel stained with ethidium bromide. Results of HIV-1 PCR analysis showed that 40 out of 41 (98%) seropositive mothers and 10 out of 29 (34%) seropositive children had detectable HIV-1 gag and pol sequences. None of the 16 seronegative mothers nor 27 seronegative or Western blot-indeterminate children had detectable HIV-1 sequences. Our results suggest that non-isotopic PCR methods are sensitive, specific, and potentially useful in the early diagnosis of HIV-1 infection in developed and developing countries.

Adolescent↗
PubMed1991

[Poverty, mental health and survival strategies].

The relation between "poverty and mental health" has long been established. However, the dynamic underlying the relation between social and psychic processes has received much less attention. This article presents certain preliminary results of research whose aim is to promote the emergence of the multiple dimensions behind the problematic of mental health in social conditions characterized by extreme poverty. In addition, the authors base their approach on the assumption that human beings, even underprivileged, are very active players, and explore the strategies that are hereby developed in order to maintain or recover their equilibrium.

Adaptation, Psychological↗
PubMed1982

[Nurses and death].

Explore the source record for details and available documents.

Attitude to Death↗