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Biomedical subjects

E Connor

Publications and source records attributed to E Connor.

At least 37 records · Page 2Linked to original sources

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

The intrapartum management of the HIV-infected mother and her infant.

The number of HIV-infected pregnant women in the United States is steadily increasing. While seroprevalence rates vary widely by geography, as many as 2 to 5 per cent of pregnant women in epicenters are seropositive. Medical management of the HIV-infected woman during labor and delivery depends on the clinical stage of her disease. Many will be asymptomatic or mildly symptomatic and can be managed as usual. For others, delivery may be complicated by concomitant infections and AIDS-related conditions. Between 25 and 40 per cent of infants born to HIV infected mothers will acquire HIV infection. Transmission of HIV from mother to her infant can occur in utero, intrapartum, or postpartum by breastfeeding. Infants who escape intrauterine infection are exposed to HIV-infected maternal blood and secretions at the time of delivery. Precautions should be taken to minimize intrapartum exposure by removing blood and secretions from the surfaces and mucous membranes of the infant as soon as possible after birth. In addition, procedures that involve disruption of the infant's intact skin should be avoided when possible until maternal blood and secretions have been removed. The risk of nosocomial transmission of HIV is low (less than 1 per cent following needlestick exposure). Nevertheless, labor and delivery represent times when exposure to blood and body fluids can be anticipated. Precautions that are designed to prevent parenteral exposure and exposure of mucous membranes and nonintact skin of health care workers to blood and body fluids should be used routinely for all patients.

Allied Health Personnel↗

Dyskeratosis congenita: report of a case and review of the literature.

A case of dyskeratosis congenita in a 10-year-old white boy is reported. The triad of oral leukoplakia, nail dystrophy, and skin pigmentation was present. Other associated anomalies included dysphagia and varied immunoglobulin levels, although there was no evidence of anemia, pancytopenia, and ocular involvement. Since it may be associated with future malignant change, dyskeratosis congenita should be considered in all cases in which an obscure white lesion exists in the mouth.

Child↗

Acquired immunodeficiency syndrome-associated renal disease in children.

Five children with acquired immunodeficiency syndrome (AIDS) and clinically significant renal disease had detailed pathologic examination of renal tissue (biopsy specimens, autopsy specimens, or both). All patients had proteinuria, hypoalbuminemia, and edema; one patient had persistent azotemia. In two cases, renal disease was the first manifestation of human immunodeficiency virus (HIV) infection. All patients had progressive renal disease, and four of the five died. Pathologic studies revealed focal glomerulosclerosis and mesangial proliferative glomerulonephritis with deposits of immunoglobulins and complement demonstrated by immunofluorescence and electron microscopy. Characteristic tubuloreticular structures were also demonstrated in the glomerular endothelial or epithelial cells in two cases. Renal disease is part of the multisystem involvement in children with AIDS. The pathogenesis of renal disease is not known, but circulating immune complexes are known to occur in children with HIV infection and may be involved.

Acquired Immunodeficiency Syndrome↗

Dilated cardiomyopathy in children with acquired immunodeficiency syndrome: a pathologic study of five cases.

Clinicopathologic features with special reference to the heart are presented in five fatal cases of acquired immunodeficiency syndrome (AIDS) in children. Three children showed clinical evidence of cardiovascular compromise or congestive heart failure. Autopsy was performed in all cases. The enlarged heart showed biventricular dilatation with grossly unremarkable valves and coronary arteries and absence of mural thrombi. Microscopic examination of the heart revealed primarily myopathic abnormalities with hypertrophy of the myocardium and only rare foci of sparse inflammatory infiltrate. The pathogenesis of dilated cardiomyopathy in these children with AIDS is not known. Infection, immunologic factors, anemia, deficiency of nutritional factor(s), and longer survival may be related to the pathogenesis. Pediatricians should be alert to the possibility of cardiac involvement in pediatric AIDS.

Acquired Immunodeficiency Syndrome↗

A comparison of the adherence of fimbriated and nonfimbriated Haemophilus influenzae type b to human adenoids in organ culture.

Adherence of fimbriated and nonfimbriated variants of a single strain of Haemophilus influenzae type b to organ cultures of human adenoidal tissue was measured by three assays, two of which were quantitative. In one assay, the adherence of radioactively labeled bacteria was measured; the numbers of CFU of bacteria per gram of adenoidal tissue were 16.0 +/- 6.7 for fimbriated bacteria and 10.2 +/- 4.0 for nonfimbriated bacteria (P less than 0.05). In the second assay, adherent CFU were determined directly; the results were 23.4 +/- 17.2 CFU/g of tissue for fimbriated bacteria and 5.1 +/- 2.2 CFU/g for the nonfimbriated variant (P less than 0.02). By combining data from the two assays it appears that fimbriated and nonfimbriated bacteria do not compete for the same site on the tissue, and that the adherent bacteria do not change their state of fimbriation under the assay conditions used. In contrast, the third assay, scanning electron microscopy, showed very poor adherence of nonfimbriated bacteria. Fimbriated bacteria, on the other hand, adhered in clusters to nonciliated epithelial cells. Overall, the data indicate that fimbriae enhance adherence of H. influenzae type b to a type of tissue that is a normal site of human colonization and that nonfimbriated bacteria adhere by a distinctly different mechanism.

Adenoids↗

Arteriopathy in children with acquired immune deficiency syndrome.

Pathologic features of the arteries of different organs (heart, lungs, kidneys, spleen, intestine, brain) seen at autopsy in 6 children with acquired immune deficiency syndrome (AIDS) are described. Small and medium-sized arteries, which were the most commonly involved, showed intimal fibrosis with fragmentation of elastic tissue, fibrosis and calcification of media with variable luminal narrowing, and a vasculitis or perivasculitis that was seen only in the brain in association with AIDS encephalopathy. In 1 case aneurysms of the right coronary artery with thrombosis and myocardial infarction were seen. Vascular inflammation, seen only in the brain, may be related to the agent associated with AIDS encephalopathy. The fibrocalcific arterial lesions most closely resemble idiopathic arterial calcification of infancy, but because of differences in age incidence, clinicopathologic and immunologic features, and the size and distribution of the involved arteries, the arterial lesions of pediatric AIDS appear to constitute a distinctive arteriopathy. Infection, secondary to immunodeficiency and resulting in increased exposure to endogenous and exogenous elastases, may be the pathogenesis. Luminal narrowing caused by arterial lesions may play a contributory role in the pathogenesis of the atrophy, cell depletion, scarring, and necrosis or infarction found in organs of children with AIDS. Pediatricians should be alerted to the possibility of arterial involvement in pediatrics AIDS.

Acquired Immunodeficiency Syndrome↗