Pediatric reference ranges for zinc protoporphyrin.

OBJECTIVES: To determine pediatric reference ranges for zinc protoporphyrin (ZPP). DESIGN AND METHODS: The study was conducted in a large pediatric hospital on patient blood specimens (n = 6,478) (0 – 17 y) accrued from January 2001 to June 2002. The data was analyzed employing the Hoffman approach, which was computer adapted. RESULTS AND CONCLUSIONS: The 2.5(th) and 97.5(th) percentiles for children age 0 to 12 months were 9 to 40 μg/dL (16.6 –73.6 μmol/mol heme) for female subjects and 8.5 to 34.5 μg/dL (15.6 – 63.5 μmol/mol heme) for males. The 97.5(th) percentiles decreased for the 13 to 24 months age group for females (32 μg/dL) (58.9 μmol/mol heme). There was a significant decrease in the 97.5(th) percentile for zinc protoporphyrin (ZPP) concentrations for the 5 to 9 yr age group, the 97.5(th) percentile being 30 μg/dL (55.2 μmol/mol heme) in both genders, which increased to 33.5 μg/dL (61.6 μmol/mol heme) in the 10 to 17 yr female age group but not for the males (31.5 μg/dL) (58.0 μmol/mol heme). The highest medians were 25.5 μg/dL (46.9 μmol/mol heme) for females, and 21.5 μg/dL (39.6 μmol/mol heme) for males in the 0 to 12 months age group

Urinary iodine percentile ranges in the United States.

BACKGROUND: The status of iodine nutrition of a population can be determined by measurement of urinary iodine concentrations since it is thought to indicate dietary iodine intake. Normally, these results are compared to population-based criteria, since there are no reference ranges for urinary iodine. OBJECTIVE: To determine the percentile ranges for urinary iodide (UI) concentrations in normal individuals in the United States. MATERIALS AND METHODS: The third National Health and Nutrition Examination Survey (NHANES III) (1988–1994) database of the civilian, non-institutionalized, iodine-sufficient US population was used. The 2.5th to 97.5th percentile ranges for urinary iodine and for urinary iodine per gram creatinine ratio (UI/Cr) (μg/g) were calculated for females and males, 6–89 years of age, each stratified by age groups. RESULTS AND CONCLUSIONS: We calculated the percentile ranges for urinary iodine. After exclusions of subjects with goiter or thyroid disease, the study sample included 21,530 subjects; 10,439 males and 11,091 females. For women of childbearing age (14–44 years), urinary iodine concentration 2.5th to 97.5th percentiles are 1.8–65 μg/dl or 36–539 μg/g creatinine. For pregnant women, the ranges are 4.2–55 μg/dl or 33–535 μg/g creatinine

Milk transfer and neonatal safety of tacrolimus

Tacrolimus, an immunosuppressant drug used orally fororgan transplantation, exhibits variable but usually low absorption from the gastrointestinal tract, and is extensive-ly bound to proteins (99%); the whole-blood-to-plasma ra-tio is approximately 20.1 Both of these factors would sug-gest that there is low excretion of the drug into human breast milk and a low risk for absorption by the suckling infant. Presently, however, breast-feeding is generally not recommended during immunotherapy, based on theoretical concerns of affecting the development of immune function in the baby. There has been only 1 published report of the measurement of tacrolimus concentrations in breast milk using immunoassay techniques,2 and the mothers in that study were counseled to abstain from breast-feeding while taking the medication despite very low concentrations of tacrolimus in the milk. We describe the first account, to the best of our knowledge, of tacrolimus measurement in hu-man milk following maternal dosing, in which the mother breast-fed while taking the medication. Case Report A 32-year-old white woman (59 kg) had undergone liver transplanta-tion in April 1997. At 35 weeks ’ gestation, nearly 5 years after transplan-tation, after having taken tacrolimus throughout pregnancy, she contact-ed the Motherisk Program inquiring about the safety of breast-feeding during maternal tacrolimus therapy. The mother had stable graft function throughout her pregnancy, and her tacrolimus dose ranged from 3 to

Pediatric reference intervals for FSH, LH, estradiol, T3, free T3, cortisol, and growth hormone on the DPC IMMULITE 1000.

BACKGROUND: We studied serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), triiodothyronine (T3), free T3 (FT3), cortisol and growth hormone (GH) concentrations in a population of pediatric patients. The reference intervals were determined separately for females and males stratified by age groups to assess age- and sex-related differences. Our objective was to obtain reference intervals for the 7 serum analytes for our pediatric population using the IMMULITE 1000 system. METHODS: Serum samples of 800 in- and out-patients, newborn to 19 years old were analyzed using the DPC IMMULITE 1000 chemiluminescent immunoassay system. RESULTS AND CONCLUSIONS: We report pediatric reference intervals for FSH, LH, E2, T3, FT3, cortisol, and GH. These reference intervals provide the basis for clinical interpretation of laboratory results using the IMMULITE 1000 system and the assessment of child development

Changing trends in the epidemiology of pediatric lead exposure: interrelationship of blood lead and ZPP concentrations and a comparison to the US population

OBJECTIVES: To determine blood lead and zinc protoporphyrin (ZPP) concentrations in a pediatric population, confirm their interrelationship at low blood lead concentrations, and assess changing trends through comparison of these data with those found in a similar population 10 years earlier and to US national values. STUDY DESIGN AND METHODS: The study was conducted in a large pediatric hospital in the Washington DC area (CNMC) on patient whole blood specimens (n = 4908) (0–17 years) accrued from January 2001 to June 2002. Pediatric blood lead concentrations were determined by atomic absorption spectrophotometry, and ZPP by hematofluorometry. The data were analyzed using a computer adaptation of the Hoffmann approach. RESULTS AND CONCLUSIONS: Blood lead level (BLL) means ranged between 2.2 and 3.3 μg/dL, and the median BLL was 3 μg/dL throughout. Mean ZPP concentrations ranged between 21.1 and 26.6 μg/dL and the median concentrations between 21 and 27 μg/dL. In comparison to data obtained from a similar pediatric population at CNMC between 1991 and 1992, pediatric BLLs have significantly declined in the Washington DC area. The current data are also compared with data obtained from the National Health and Nutrition Examination Survey (NHANES III) of the US population. The interrelationship between ZPP and BLLs is examined