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Biomedical subjects

H Mendez

Publications and source records attributed to H Mendez.

At least 55 records · Page 3Linked to original sources
PubMed1994

Cigarette smoking, premature rupture of membranes, and vertical transmission of HIV-1 among women with low CD4+ levels.

To examine the possible influence of obstetric factors, substance use during pregnancy, and other maternal factors on the relationship between a low maternal CD4+ level and vertical transmission of human immunodeficiency virus type 1 (HIV-1), data were analyzed from the Mothers and Infants Cohort Study, a prospective cohort followed for up to 4 years between 1986 and 1992 in Brooklyn and the Bronx, New York. The overall transmission rate for the cohort was 25.1% (95% confidence interval (CI) = 19.0-31.3). Prenatal CD4+ lymphocyte measurements were available for 162 HIV-seropositive mothers of infants with known infection outcomes. Among mothers who smoked cigarettes after the first trimester, those whose mean prenatal CD4+ level was < 20% had more than a threefold increased risk of transmitting their infection to their infants [relative risk (RR) = 3.30; 95% CI = 1.46-7.44; p = 0.004]. Among mothers who developed premature rupture of membranes, those with a low CD4+ level had a similarly increased risk of vertical transmission (RR = 4.33; 95% CI = 1.78-10.5; p = 0.003). These relative risks were much higher than those for mothers who did not smoke after the first trimester (RR = 1.14; 95% CI = 0.48-2.70; p = 0.76) or have premature rupture of membranes (RR = 1.29; 95% CI = 0.61-2.74; p = 0.50), indicating that these factors modified the effect of CD4+ level on transmission. Among all mothers without regard to CD4+ level, those who experienced preterm premature rupture of membranes were also at greater risk of transmission (RR = 2.24; 95% CI = 1.07-4.69; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Epidemiology of persistent diarrhea among Guatemalan rural children.

A prospective, longitudinal two-year study to determine the epidemiology of persistent (> or = 14 days' duration) diarrhea in rural children of Guatemala was undertaken. Three-hundred and twenty-one children aged 0-35 months were kept under surveillance by twice-a-week home visits. The overall incidence of diarrhea was 0.147 per child-week; the incidence of persistent diarrhea was 0.014 per child-week. The peak of persistent diarrhea was observed in infants below six months of age, with a continuous decline thereafter. This trend in incidence of persistent diarrhea was associated with a higher proportion (16%) of illnesses persisting for more than 13 days in children younger than six months of age as compared to children 30-35 months old (4%). Males had more diarrhea (0.156 per child-week) than females (0.139 per child week). Among children above 18 months of age, the proportion of episodes that lasted for more than 13 days was lower in females than in males.

Acute Disease↗
PubMed1992

Association of indicators of hygiene behavior with persistent diarrhea of young children.

We examined the association between water and hygiene-related behaviors and persistent diarrhea (duration > or = 14 days) among children under age three years in an indigenous rural Guatemalan community. Behavior indicators were specific aspects of the appearance of the mother, study child, other children and household that could be observed using a spot observation technique. Thirty-four percent of children had one or more episodes of persistent diarrhea during the year of study. Bivariate analyses found that a higher proportion of observations in which the anti-hygienic condition was observed was significantly associated with persistent diarrhea for 11 of 26 behavior indicators; these 11 indicators were also strongly correlated with each other. In individual logistic regression models, which included overall rate of diarrhea and other child characteristics associated with persistent diarrhea, six behavior indicators maintained significant association with persistent diarrhea: presence of toy on the ground, presence of baby bottle on the ground, the hands of the mother being dirty, presence of a fecally soiled diaper on the ground in the household compound, presence of feces in the yard, and the study child wearing a fecally soiled diaper. Three additional indicators closely approached significant association with persistent diarrhea. Excluding the three soiled diaper indicators, which might be the result rather than the cause of diarrhea, we found the six other behavior indicators to demonstrate a significant dose-response effect in increasing risk of persistent diarrhea. These findings suggest that behaviors which promote increased exposure of young children to enteric pathogens increase risk of persistent diarrhea.

Behavior↗
PubMed1992

Vertical transmission of human immunodeficiency virus (HIV) infection. Reactivity of maternal sera with glycoprotein 120 and 41 peptides from HIV type 1.

The observation that approximately 70% of HIV-infected pregnant women do not transmit infection vertically suggests that antibody therapy may be effective in the prevention of transmission of HIV infection from mother to child. Currently, there is an incomplete understanding of the processes involved in vertical transmission of HIV infection. The elucidation of the serological basis of maternal immunity as it relates to protection from vertical transmission is the goal of this study. We have screened 20 maternal sera from HIV+ individuals of known vertical transmission status for reactivity with 31 peptides spanning the entire envelope glycoprotein of HIV-1. Of interest was reactivity to regions outside of the V3 loop of gp120. The findings have been examined in relationship to transmission status, as well as to in vitro anti-HIV-1 biological activity. Our results indicate that lack of vertical transmission is correlated with high viral neutralization activity, but not with antisyncytial activity nor with binding to the V3 peptides examined in this study. Also, the transmission group bound to fewer gp41 peptides when compared with the nontransmission group, suggesting that immune responses to gp41 may be important in preventing transmission. These findings may provide insights into the design of passive immunotherapies.

Adult↗
PubMed1991

Clinical utility of HIV-IgA immunoblot assay in the early diagnosis of perinatal HIV infection.

OBJECTIVE: To ascertain the sensitivity, specificity, predictive value, and clinical use of a human immunodeficiency virus (HIV)-IgA immunoblot assay for diagnosing perinatal HIV infection in infants tested at birth to 1 month, 3 months, and 6 months of age. DESIGN: Prospective, longitudinal cohort study of children born to HIV-infected and noninfected women. The HIV-IgA immunoblot assays were performed at birth to 1 month, 3 months, and 6 months of age and compared with the Centers for Disease Control's classification system of HIV infection in the children. Children were followed up for at least 15 months to ensure accuracy of infection status. SETTING: Municipal hospital in central Brooklyn, NY, where the prevalence of HIV infection is high. PATIENTS: Serum samples from 58 children, 22 with documented HIV infection, 18 noninfected children born to seropositive women, and 18 children born to noninfected women, were studied. MAIN OUTCOME MEASURE: Diagnosis of HIV infection using the Centers for Disease Control's classification scheme was compared with diagnosis using the HIV-IgA immunoblot assay for children 6 months of age or younger. RESULTS: The HIV-IgA immunoblot assay yielded negative results at 3 and 6 months of age for all 18 infants born to seronegative women; for the 18 seroreverting, noninfected children born to infected women, the assay yielded negative results at 1 month, 3 months, and 6 months of age. The positive predictive value of the assay was 100%--no false-positive results were identified in the 88 serum samples obtained from noninfected infants. For the HIV-infected children, sensitivity was a function of age: one (5.9%) of 17 infants had an assay that yielded positive results at birth to 1 month of age, 13 (62%) of 21 infants had assays that yielded positive results at 3 months of age, and 17 (77%) of 22 infants had assays that yielded positive results at 6 months of age. The presence or absence of symptoms did not affect the sensitivity. CONCLUSION: The HIV-IgA immunoblot assay can detect a significant proportion of infected children during an early asymptomatic period of their life. This relatively inexpensive, easily standardized assay may allow for institution of therapy before the onset of clinical symptoms.

Female↗
PubMed1990

Early diagnosis of HIV infection in infants by detection of IgA HIV antibodies.

With the aim of achieving earlier diagnosis of human, immunodeficiency virus (HIV) infection in infants, IgA and IgM HIV antibodies in serum samples from babies born to seropositive mothers were assayed by immunoblot and enzyme-linked immunosorbent assay after removal of IgG with recombinant protein G. 64 samples were from 38 HIV-infected babies with Centers for Disease Control classifications of P1 or P2. Among these infected children IgA HIV antibodies were present in all 23 samples from those older than 12 months, in 12 of 18 samples from babies aged 6-12 months, in 5 of 10 samples from babies aged 3-5 months, and in 2 of 13 from babies under 3 months old. The 6 IgA-negative samples from infants over 6 months were all from infants with severe AIDS and/or hypogammaglobulinaemia. IgA HIV antibodies were present in twice as many samples as IgM HIV antibodies (66% vs 33%). No IgM or IgA HIV antibodies were detected in infants who subsequently seroreverted or in infants born to seronegative mothers. The correlation of the serological results with clinical information on each child suggests that detection of IgA HIV antibodies is an effective method for early diagnosis of HIV-infected infants without signs of infection.

AIDS Serodiagnosis↗
PubMed1990

Serious infections during pregnancy among women with advanced human immunodeficiency virus infection.

Fifty-six human immunodeficiency virus seropositive-women and 76 human immunodeficiency virus seronegative-women had known CD4 cell values and were followed up throughout pregnancy. The women with seronegative results and the 40 with seropositive results and CD4 (helper cell) counts consistently greater than 300 cells/mm3 had no serious infections during pregnancy. Among the 16 with seropositive results and counts that fell below 300 cells/mm3, three developed opportunistic infections, one had pneumonia, and one had a post-cesarean-section abscess. Human immunodeficiency virus seropositive-women with low CD4 counts are at markedly increased risk of serious infections during pregnancy. The consequences of this for fetal health, pregnancy management, maternal well-being, and human immunodeficiency virus testing policies are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Care of the infant born exposed to human immunodeficiency virus.

The expanding epidemic of HIV infection in reproductive-age women, the availability of antiretroviral therapy for children, and recommendations for increased case identification activities augur a time when more and more pediatricians are going to be called on to care for HIV-exposed infants. This article outlines a comprehensive medical framework for the care of these children from the labor and delivery setting to the nursery, outpatient clinic, and the emergency room. It includes issues of infection control; medical, developmental, and psychosocial care; and laboratory evaluations. Finally, it address the need for long-term follow-up of all children born exposed to HIV.

Aftercare↗
PubMed1990

Pregnancy outcomes among mothers infected with human immunodeficiency virus and uninfected control subjects.

Between June 26, 1985, and Feb. 24, 1989, 101 seropositive pregnant women and 129 seronegative pregnant women from the same prenatal clinics in Brooklyn and the Bronx were recruited into a prospective study of human immunodeficiency virus infection in pregnant women and their offspring. This report details the course of pregnancy and short-term neonatal outcomes of 91 seropositive women and 126 seronegative women who gave birth during the study period. Seropositive mothers were significantly more likely to have sexually transmitted diseases (17.6% vs 7.1%, p = 0.017) and medical complications (43.0% vs 25%, p = 0.006) during pregnancy. No other obstetric complications (e. g., chorioamnionitis, endometritis, toxemia, or placental problems) were associated with serologic status. After controlling for confounding variables (drug use, tobacco use, age of mother, and clinic), we found that the mother's serologic status was not significantly associated with birth weight, gestational age, head circumference, or Apgar scores among live infants. For example, after adjustment on confounders we found that children born to seropositive mothers weighed about 7 gm more than children of seronegative mothers (95% confidence interval, -180 to 194 gm). We conclude that in this population human immunodeficiency virus infection has little demonstrable impact on the status at birth of live neonates.

Adult↗
PubMed1989

Mother-to-infant transmission of human immunodeficiency virus type 1: association with prematurity or low anti-gp120.

In a prospective study of pregnant women infected with human immunodeficiency virus type 1 (HIV-1) in Brooklyn, New York, USA, 16 (29%) of 55 evaluable infants were infected with HIV-1. 9 infants had paediatric acquired immunodeficiency syndrome, 6 had less severe clinical manifestations of HIV-1 infection, and 1 was symptom-free but was seropositive for HIV-1 beyond 15 months of age. The 10 infants born at 37 weeks of gestation or earlier were at higher risk of HIV-1 infection than infants born at 38 weeks of gestation or later (60% vs 22%) but the median age at appearance of disease was approximately 5 months in both groups. The HIV-1 transmission rate was not associated with predelivery levels of maternal T cells, anti-p24, or neutralising antibodies but it was higher, among full-term infants, for those with mothers in the lowest third of the distribution of anti-gp120 levels (53%). On immunoblot, transmitting mothers lacked a gp120 band but not other bands. Protection was not associated with antibody to recombinant peptides from the hypervariable region of the major neutralising gp120 epitope, and the anti-gp120 endpoint dilution titre was similar in transmitting and non-transmitting mothers. Mothers of uninfected full-term infants appear to confer immunological protection against HIV-1 infection of their offspring by way of a high-affinity antibody to a gp120 epitope, whose specificity has importance for vaccine development and possibly perinatal immunotherapy.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Pediatric human immunodeficiency virus infection and its cutaneous manifestations.

Acquired immunodeficiency syndrome was first observed in children in 1982. Human immunodeficiency virus (HIV) is now known to be the etiologic agent of this disease complex. Children acquire the viral infection in utero or perinatally, or by receiving contaminated blood products. The cutaneous manifestations include persistent oral thrush, herpes simplex, herpes zoster, molluscum contagiosum, and a variety of fungal and bacterial skin infections. Vasculitis, unusual drug eruptions, and cutaneous manifestations of nutritional deficiencies are also seen.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Introduction to the study of pre- and postnatal growth in humans: a review.

This review is divided in several items. A brief introduction on the characterization of the growth processes is made; the ways of assessing fetal development and well-being, the factors acting on fetal growth and birth weight, the causes and post-natal consequences of prematurity and intrauterine growth retardation are discussed in the first part. The following items deal mainly with: the normal pattern of growth from birth to puberty according to sex, race, and nutritional status, with special mention to pubertal changes; methods for predicting adult height from skeletal age; the effect of hormones during pre- and post-natal life; and the genetics of adult stature. The remainder of this review deals with genetic causes of growth abnormalities. Constitutional delay of growth, familial short stature, hypothalamic-pituitary dwarfism, skeletal dysplasias and many genetic syndromes presenting intrauterine growth retardation are listed. Aneuploidy effects on human growth are extensively reviewed, and usual growth patterns in Down and Ullrich-Turner syndrome patients as well as other sex aneuploid individuals and mosaics are fully described. The influences of X and Y chromosomes on growth and maturation are also discussed. Finally, some remarks are made about overgrowth syndromes.

Adolescent↗