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R Yogev

Publications and source records attributed to R Yogev.

11 recordsLinked 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

Bacterial and fungal colonization of endotracheal tubes in children: a prospective study.

OBJECTIVES: To evaluate both the frequency and route of endotracheal colonization of intubated children by pathogens and to assess the usefulness of Pediatric Risk of Mortality scoring and measurement of gastric pH in predicting this colonization. DESIGN: Prospective data collection. SETTING: A multidisciplinary pediatric ICU. PATIENTS: Nineteen children with medical/surgical problems who were intubated for at least 4 days. INTERVENTIONS: Buccal mucosa, and endotracheal and gastric aspirates were cultured for pathogens immediately after endotracheal intubation and daily for 4 to 5 days. Pediatric Risk of Mortality scores were calculated at the time of endotracheal intubation; gastric pH was measured each time that the cultures were obtained. MEASUREMENTS AND MAIN RESULTS: The buccal mucosae of ten (53%) of 19 children were colonized with Candida species at the time of endotracheal intubation. This colonization correlated with the degree of physiologic instability as measured by Pediatric Risk of Mortality scores (12.9 +/- 2.8 SEM for those patients colonized vs. 4.9 +/- 1.0 for those patients not colonized; p = .01), but not with preintubation antibiotic therapy. Eleven (58%) children acquired 27 endotracheal pathogens after the day of intubation. The buccal mucosa was the initial site of colonization of 19 (70%) of 27 of the acquired pathogens. A gastric pH of > 3.0 at the time of intubation correctly predicted colonization in nine of 11 children (p < .025, Fisher's exact test); a Pediatric Risk of Mortality score of > 8 at the time of endotracheal intubation correctly predicted colonization in eight of 11 patients (p < .05, Fisher's exact test). CONCLUSIONS: Colonization of the buccal mucosa appears to be the crucial antecedent to endotracheal colonization in children. In children, gastric pH and Pediatric Risk of Mortality scores at the time of endotracheal intubation can predict pathogenic endotracheal colonization within 4 days of intubation. Selective decontamination regimes may be appropriate for these patients, especially those regimes that are directed to the buccal mucosa.

Adolescent

Ventricular fluid levels of chloramphenicol in infants.

Investigation of two infants suggested that peak ventricular fluid levels of chloramphenicol after intravenous administration were achieved after 3 h. The penetration of chloramphenicol into ventricular fluid may be unpredictable. In one patient, the peak ventricular fluid level was 57.5% of the peak serum level, and it was only 22.5% in the other patient. This observation may explain some of the past treatment failures when chloramphenicol was utilized in patients with gram-negative ventriculitis and meningitis.

Brain Diseases

Ventriculitis from Acinetobacter calcoaceticus variant anitratus.

Ventriculitis from infection with Acinetobacter calcoaceticus variant anitratus occurred in an infant two weeks after surgical repair of a lumbosacral meningomyelocele and ventriculoperitoneal shunting. Recovery took place on replacing the shunt with an extraventricular deviation device and giving gentamicin and ampicillin intravenously.

Acinetobacter Infections

Viral hepatitis.

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Adult

Effect of TMP-SMX on nasopharyngeal carriage of ampicillin-sensitive and ampicillin-resistant hemophilus influenzae type B.

The carriage rate of ampicillin-resistant Hemophilus influenzae type B in a chronic care facility was investigated. Up to 48% of the children carried this strain. Of interest was the finding of simulaneous carriage of ampicillin-resistant and ampicillin-sensitive HITB, a phenomenon which was detected by using both chocolate agar and chocolate agar containing 2 microgram/ml of ampicillin. A trial of sulfamethoxazole-trimethoprin successfully eradicated the ampicillin-sensitive HITB, but had no effect on the ampicillin-resistant HITB.

Ampicillin

Enterobacter aerogenes primary bacteremia in pediatric patients.

Enterobacter aerogenes bacteremia associated with the infusion of contaminated admixed intravenous (IV) fluid occurred in seven patients in a pediatric hospital over a five-day period. Clinical illness was characterized by spiking fever in all patients. The temporal clustering of cases allowed for rapid recognition of the problem. The primary control measure was the prompt replacement of the IV fluids, although IV antibiotics were also administered. Hospital pharmacy practices for admixing IV solutions should follow published recommendations to minimize this source of potential contamination of fluids.

Child