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Biomedical subjects

E Connor

Publications and source records attributed to E Connor.

15 recordsLinked to original sources
PubMed1992

Lymphocyte subsets in healthy children during the first 5 years of life.

OBJECTIVE: To assess whether relative and absolute values of CD4 and CD8 lymphocytes and CD4/CD8 ratio change in relation to age, and to estimate the fifth and 95th percentiles for these values in children of various ages. PATIENTS AND METHODS: Phenotypic analysis of lymphocyte subsets was performed on blood samples from 208 healthy children, aged 1 through 59 months, using standard flow cytometric techniques. RESULTS: Regression analysis demonstrated that CD4 and CD8 lymphocyte counts declined significantly with advancing age (P less than .000001 and P = .03, respectively). Since CD4 and CD8 counts depend on total lymphocyte count, the percentage of total lymphocytes of each phenotype was also analyzed and demonstrated that the CD4 percentage was highly age dependent (P less than .000001). The CD8 percentage increased with age (P = .0001) but not as much as the CD4 percentage decreased. Median CD4 counts (fifth and 95th percentiles) for children 2 through 3, 4 through 8, 12 through 23, and 24 through 59 months of age were 2.83 (1.46 to 5.11), 2.95 (1.69 to 4.61), 2.07 (1.02 to 3.60), and 1.80 (0.90 to 2.86) x 10(9)/L, respectively. CONCLUSION: Healthy children's CD4 lymphocyte counts are considerably higher than previously established adult values. These data demonstrate that age is an important consideration in interpretation of lymphocyte subsets in children. This may be especially relevant in children who are infected with the human immunodeficiency virus, where CD4 lymphocyte values play a central role in monitoring disease progression and determining thresholds for medical interventions.

CD4-CD8 Ratio↗
PubMed1992

Nontuberculous mycobacteria in children with acquired immunodeficiency syndrome.

Among 139 children with acquired immunodeficiency syndrome at Children's Hospital of New Jersey, 20 had positive cultures for non-tuberculous mycobacteria. Eighty-five percent had Mycobacterium avium complex isolated and 70% had definite evidence of disseminated disease. Ninety-three percent had CD4 lymphocyte counts less than 100 cells/mm3 and 95% had met acquired immunodeficiency syndrome criteria before the time of first positive culture. Clinical findings included failure to gain weight, anorexia, fever, abdominal pain/tenderness and anemia. The median age at onset of symptoms was 46 months and the median time between onset of symptoms and positive culture was 9 months. Outcome for patients with positive cultures for nontuberculous mycobacteria was poor, with 75% of the children surviving for less than or equal to 10 months. Nontuberculous mycobacteria are increasingly important causes of morbidity and indirect mortality in human immunodeficiency-infected children. Children with severe immunodeficiency are at particular risk. In addition to M. avium complex, other species of nontuberculous mycobacteria may be involved.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Varicella does not appear to be a cofactor for human immunodeficiency virus infection in children.

We performed a retrospective analysis of longitudinal clinical and immunologic data obtained from 22 children in the early stages of infection with human immunodeficiency virus (HIV) when they developed varicella. We studied the course of HIV infection to determine whether clinical deterioration occurred after chickenpox. We examined the following indices: growth and development; neurologic status; helper T lymphocyte counts; blood values of core (p24) antigen of HIV; changes in the stage of HIV infection; and need for administration of zidovudine. We studied children for a mean of 2.8 years and for as long as 9.8 years after onset of varicella. There was little evidence that chickenpox affected HIV infection. Three (14%) children developed clinical zoster, 2 of whom (9%) had evidence of chronic infection with varicella-zoster virus. One additional child (5%) had 2 episodes of chickenpox. These observations suggest that children with early HIV infection could be considered for immunization with live attenuated varicella vaccine, which would be predicted to decrease their morbidity from varicella-zoster virus.

CD4-Positive T-Lymphocytes↗
PubMed1992

Population-based study of measles and measles immunization in human immunodeficiency virus-infected children.

This study reports the course of measles and results of measles immunization in a cohort of human immunodeficiency virus-infected children. Six cases of measles were identified. All had typical clinical manifestations, 5 of 6 developed pneumonia and 3 of 6 died. A measles intervention program consisting of serologic screening and active immunization (measles-mumps-rubella (MMR)) was instituted in 1990. Among 127 children with data available for analysis (mean age, 6.7 years), only 35% had documentation of prior immunization with MMR. Among 80 children who had preimmunization measles serology reported, 56% were measles antibody-negative and 40% were antibody-positive; following intervention 36% remained measles antibody-negative. Six children lost measles antibody over time. MMR nonresponders had lower CD4 lymphocyte counts (303 +/- 394) compared with responders (865 +/- 677; P = 0.0058). Measles is a potentially fatal illness in human immunodeficiency virus-infected children. Prevention strategies are limited by low rates of age-appropriate MMR immunization, poor antibody responses to MMR in older human immunodeficiency virus-infected children and seroreversion.

Child↗
PubMed1991

Renal heme metabolism in hereditary tyrosinemia: use of succinylacetone in rat renal tubules.

Succinylacetone (SA), a metabolic end-product found in urine from individuals with hereditary tyrosinemia and associated renal Fanconi syndrome and a known inhibitor of hepatic 5-aminolevulinic acid dehydratase (ALAD), has been used to study heme metabolism in isolated rat renal tubules. Heme biosynthetic porphyrin precursors are increased selectively in the presence of 4 mmol/1 SA. Total porphyrin content of the tubules are increased approximately 2-fold, while both ferrochelatase and heme oxygenase activities remain unaffected by SA. Nonetheless, total heme content is reduced, as was incorporation of radioactive label from amino[14C]levulinic acid. Cytochrome P-450 content remained unaffected. Impairment of iron uptake and/or transport within the cell or enhancement of heme catabolism via a non-heme oxygenase-dependent pathway could explain the observations.

Amino Acid Metabolism, Inborn Errors↗
PubMed1991

Clinical and laboratory correlates of Pneumocystis carinii pneumonia in children infected with HIV.

The case histories of 27 children with Pneumocystis carinii pneumonia (PCP) who were followed up in the AIDS Program at the Children's Hospital of New Jersey, Newark, are reviewed. The mean and median age at PCP diagnosis were 10.8 and 7.7 months, respectively. All of the children had other clinical evidence of infection with the human immunodeficiency virus that was documented prior to the diagnosis of PCP or found at the time of PCP diagnosis. Most patients who presented to the hospital were acutely ill, and complications of treatment occurred in 70%. Overall, 89% of the patients died and 70% survived for less than 6 months after diagnosis of PCP. Median survival after the diagnosis of PCP was only 2.0 months and the median life span of children with PCP was only 14.4 months. Only 40% of children with PCP had CD4 lymphocyte counts at or below the threshold for institution of PCP prophylaxis in adults of 200 x 10(6) cells/L (200 cells/mm3).

CD4-Positive T-Lymphocytes↗
PubMed1991

Insulin dependent diabetes 1991.

Insulin dependent diabetes (IDD) most often results from the autoimmune destruction of pancreatic beta cells. During this process, autoantibodies to islet cell constituents (islet cell cytoplasm, 64KDa protein [GAD]) and to insulin arise and can be used for disease prediction if found before onset or for classification at onset in cases in which type of diabetes is not clear. Approximately 4-5% of immediate family members have at least one of these antibodies. The younger the age and the higher the antibody titer, the greater the chance of IDD developing. Because studies using immunosuppression in newly-diagnosed IDD have shown transient prolongation of beta cell function, efforts to use such therapies prior to diabetes onset may prevent beta cell destruction and clinical disease. A multicenter trial is underway in Florida to screen relatives for diabetes-related antibodies and then to enter those found positive and at increased risk in a study to prevent diabetes. Details of the study and its rationale are presented.

Autoimmune Diseases↗
PubMed1990

Cutaneous acquired immunodeficiency syndrome-associated Kaposi's sarcoma in pediatric patients.

Kaposi's sarcoma has only rarely been reported in children with acquired immunodeficiency syndrome. In contrast to adult patients, in whom the disease is predominantly cutaneous, among pediatric patients with acquired immunodeficiency syndrome, Kaposi's sarcoma is primarily limited to the lymphadenopathic form. We describe two children with the acquired immunodeficiency syndrome who developed diffuse nodular skin lesions of Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1977

A simple hypoxic chamber.

A simple, normobaric hypoxic chamber constructed of easily obtainable parts is described. Important features include small size, low cost, simple construction, and easy maintenance. The chamber accommodates 50 mice and can be used for rats as well. Although designed to provide animals for the in vivo bioassay of erythropoietin, it is also useful for experimental studies requiring the acute induction of hypoxia.

Animals↗