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Biomedical subjects

L M Bell

Publications and source records attributed to L M Bell.

66 records · Page 4Linked to original sources

Immune response of infants and children to low-passage bovine rotavirus (strain WC3).

A bovine rotavirus (strain WC3) was isolated from a calf in Pennsylvania and adapted to growth in continuous Cercopithecus cell line CV1. A pool for human vaccine trials was produced at the 12th cell culture passage level. After preliminary testing in adults and older children, a dose of 3 X 10(7) plaque-forming units was given by mouth to 52 infants and children aged 5 months to 6 years. No clinical sequelae were detected, and shedding in feces was detected in only 30% of tested infants. A serum-neutralizing antibody response was induced in 95% of 21 infants aged 5 to 11 months; response rates were slightly reduced in older infants. The antibody response was primarily directed toward bovine rotavirus, but a response to human serotype 3 rotavirus was also observed in approximately 50% of vaccinees. After vaccination with WC3, infants with preexisting antibody to rotaviruses of human serotype 1 or 3 frequently exhibited a booster response to those serotypes. WC3 is a candidate rotaviral vaccine deserving larger trials in children.

Adult↗

Outbreak of cryptosporidiosis in a day-care center.

An outbreak of diarrhea due to infection with Cryptosporidium occurred in a day-care center. During a period of 2 months, 23 of 53 (43%) children attending the day-care center and 15 of 104 (14%) household contacts had diarrhea. Cryptosporidium oocysts were identified in 13 of 20 (65%) symptomatic children tested compared with three of 27 (11%) asymptomatic children (chi 2 = 12.56, P less than .001). Enteropathogenic bacteria, enteroviruses, rotavirus, and other protozoan parasites were ruled out as the cause of the diarrhea. A history of diarrhea in household contacts was associated with excretion of Cryptosporidium oocysts by the children. Human-to-human transmission of the infection was suggested by the epidemiology.

Child Day Care Centers↗

Epidemiology of rotavirus electropherotypes determined by a simplified diagnostic technique with RNA analysis.

The incidence and RNA electropherotypes of rotavirus in stools or rectal swabs of children with diarrhea were studied for three rotavirus seasons (1981 through 1984) in Philadelphia, Pa. We used a simplified RNA analysis method involving polyacrylamide gel electrophoresis followed by silver staining. Phosphate-buffered saline suspensions of the stools and swab eluates were examined directly by polyacrylamide gel electrophoresis-silver staining analysis and enzyme-linked immunoadsorbent assay (Rotazyme; Abbott Laboratories); electron microscopy was performed on solid stool specimens. The RNA analysis results were compared with electron microscopy and enzyme-linked immunosorbent assay results and exhibited a sensitivity and specificity greater than or equal to that of electron microscopy or the enzyme-linked immunosorbent assay. Ten different electropherotypes were detected among the 68 rotavirus RNA-positive specimens examined over the 3-year study. The predominant electropherotype was different in each season. Our results indicate that the polyacrylamide gel electrophoresis-silver nitrate strain RNA analysis of simple unextracted stool suspensions is a uniquely useful diagnostic technique; it rapidly provides both a definitive positive result and immediate determination of the RNA electropherotype, which is of value for epidemiological study.

Electrophoresis, Polyacrylamide Gel↗

Routine quantitative blood cultures in children with Haemophilus influenzae or Streptococcus pneumoniae bacteremia.

The potential clinical value of quantitative blood cultures determined by a commercially available lysis-direct plating method was studied in 50 children with either Haemophilus influenzae or Streptococcus pneumoniae bacteremia. The magnitude of bacteremia correlated with the severity of the infection; patients with greater than or equal to 100 colony-forming units per milliliter were significantly more likely to have meningitis (P less than .01, chi 2 = 7.5). On the other hand, all patients with S. pneumoniae bacteremia with colony counts lower than 15 colony-forming units per milliliter had "occult bacteremia" with no focus of infection. The data suggest that patients with higher levels of bacteremia have more severe disease. Quantitative blood culture results may be helpful in identifying which children are at risk for invasive disease.

Colony-Forming Units Assay↗

Teaching technical skills in pediatrics.

Technical skills are an important and difficult part of managing a very sick or injured child. However, technical procedures are more often learned from experience than practice. This article reviews a variety of technical skills and procedures commonly performed in a pediatric emergency department. Each technical procedure can be practiced using live or artificial model for simulation.

Clinical Competence↗

Pharmacokinetics of single daily dose gentamicin in children with cancer.

PURPOSE: To study the pharmacokinetics of single daily dose (SDD) gentamicin in children with cancer. METHODS: Serum concentrations of gentamicin were prospectively measured at 0.5, 8, 16, and 24 hours after a single daily dose of gentamicin 6 mg/kg, given as a 30-minute infusion in 18 febrile children with cancer and a central venous catheter. Then the peak (0.5-hour) and 12-hour serum concentrations of gentamicin were prospectively measured after a SDD of 7 mg/kg during 73 febrile episodes in 54 pediatric cancer patients with suspected infections. The aim was to achieve a peak serum concentration of 15 to 20 microg/mL 10 times the minimum inhibitory concentration (MIC) for sensitive Pseudomonas strains, resulting in good bactericidal activity and a long post-antibiotic effect (PAE) after a SDD of gentamicin. RESULTS: The mean serum peak gentamicin concentration 30 minutes after the end of the infusion of 6 mg/kg was 13.3 +/- 4.0 microg/mL. The mean serum concentration 16 hours after the infusion was 0.3 +/- 0.2 microg/mL. The mean peak and 12-hour serum concentration after SDD of 7 mg/kg was 17.2 +/- 3.9 microg/mL and 0.9 +/- 0.7 microg/mL, respectively. The mean peak serum concentration after SDD of 7 mg/kg in children younger than 5 years of age (16.1 +/- 3.5 microg/mL ) was significantly lower than that of children over 5 years of age (18.2 +/- 3.9 microg/mL; P = 0.02). The desired peak serum concentration was achieved in 67% of children younger and 84% of those older than 5 years of age. CONCLUSION: Adequate peak serum concentrations of gentamicin in children may be obtained with a SDD of 7 mg/kg. Children younger than 5 years of age achieve lower peak serum gentamicin concentration after SDD of 7 mg/kg than those older than 5 years.

Antibiotics, Antineoplastic↗

Evidence of reservior hosts of Brucella mellitensis.

Serological reactors to Brucella melitensis were found among goats and eland in Chilanga. The only clinical evidence of disease were abortion among the goats, and circumstances did not allow for isolation of the organism in the laboratory. No gross pathological lesions were observed on post mortem examination of the goats. The public health significance relates to the ease of Br. melitensis transmission between reservoir hosts and human beings.

Animals↗

Inpatient immunization program: eliminating a missed opportunity.

In response to the nation's low immunization rates among preschool-aged children, health care providers need to consider alternate sites as potential opportunities to administer vaccinations. One hospital established a Childhood Immunization Group designed to identify and provide immunizations to hospitalized children, 0-2 years of age. Sixty percent of the over 1,600 children evaluated have required immunizations in which 70% of these were immunized prior to discharge. The integration of primary care with "hospital care" can contribute to improving the immunization rate of preschool-aged children.

Child Health Services↗