Harold S. Cole

Light (phototherapy)-induced riboflavin deficiency in the neonate

Phototherapy with blue light decomposes riboflavin, which has a maximum absorption at 450 nm. A study was designed to determine whether riboflavin deficiency developed in neonates who received phototherapy for moderate hyperbilirubinemia. Twenty-one infants with normal erythrocyte glucose-6-phosphate dehydrogenase activity were investigated. Five infants with moderate hyperbilirubinemia who did not require phototherapy served as the controls. Riboflavin deficiency was determined from the degree of saturation of erythrocyte glutathione reductase, a method shown to reflect riboflavin nutritional status in the neonate. Sixteen of 21 infants who were exposed to phototherapy developed riboflavin deficiency; all who had phototherapy for 49 hours or more developed the deficiency. That the concentration of serum bilirubin or the duration of hyperbilirubinemia was not a factor is supported by the fact that none of the controls became deficient. This observation may have important metabolic and clinical consequences for the neonate.

Erythrocyte Glutathione Reductase as a Measure of Riboflavin Nutritional Status of Pregnant Women and Newborns

Summary The assay of erythrocyte glutathione reductase (EGR) used to assess the riboflavin nutritional status has been modified to increase its utility. The levels of EGR in cord blood are significantly higher than those in the blood of well-nourished pregnant women at term. In both maternal and cord blood the activity coefficients (AC) were near 1, indicating that the EGR in both was saturated with FAD. This method to determine riboflavin deficiency can be applied to both pregnant women and newborns, and is not affected by increased reticulocytes.

Riboflavin deficiency in children with diabetes mellitus

SummaryTwenty-four insulin-dependent diabetic children and 114 normal control children, all between the ages of 6 to 16 years, were investigated for riboflavin deficiency. The method used was a measurement of erythrocyte glutathione reductase activity and the results were expressed as the activity coefficient (AC). None of the children had received vitamin supplementation. The percentage of diabetic children with riboflavin deficiency was 4 fold greater than in non diabetics. Supplementation with daily oral riboflavin quickly returned all AC values to normal.

Riboflavin deficiency in a pediatric population of low socioeconomic status in New York City.

1. Chantler C, Baum JD, and Norman DA: Dextrostix in the diagnosis of neonatal hypoglycemia, Lancet 2:1395, 1967. 2. Ente G, Klein SW, and Paraswanath BS: Evaluation of a direct-reading reflectometer for neonatal hypoglycemia screening, Am J Clin Pathol 61:612, 1974. 3. Levkoff AH, Duncan RC, Urquhart C, and Gershank JJ: Measuring neonatal blood glucose with a reflectance meter and test strips, Israel J Med Sci 7:598, 1971. 4. Schersten B, Kuhl C, Hollender A, and Ekman R: Blood glucose measurements with Dextrostix and new reflectance meter, Br Med J 3:384, 1974. 5. Snedecor GW, and Cochran WG: Statistical methods, ed 6, Ames, Iowa, 1972, Iowa State University Press, Chapters 6 and 7.

A sensitive micromethod for the simultaneous determination of insulin and growth hormone by double antibody precipitation

Summary 1. A sensitive and relatively simple micro-radioimmunoassay is described, by which immunoreactive insulin and growth hormone can be measured simultaneously in a volume of only 0.025 ml of serum, allowing the determination of concentrations as low as 2.5 uU/ml for insulin and 0.5 mμg/ml for growth hormone. 2. The assay offers a precision (coefficient of variation 8–12 per cent), comparable to the macromethods, which measure the two hormones separately. 3. This method requires a relatively short incubation time and allows the processing of large numbers of samples with reduced and consequently less expensive reagent volumes. 4. It also provides the possibility of measuring two hormones simultaneously in newborn infants and small laboratory animals, where sample size is very limited.

Serum Insulin and Growth Hormone Values in Children during the Oral Glucose Tolerance Test

Three-hour oral glucose tolerance tests were performed on 125 nonobese children in three age groups: One-and-one-half to less than four years, four years to less than eight years and eight to twelve years of age. All children were in good health and had negative family histories for diabetes. Oral glucose was administered according to age and weight. Capillary blood was collected and analyzed for blood sugar and serum insulin and growth hormone. All insulin and growth hormone analyses were performed on specimens from children whose blood sugar values during the oral glucose tolerance test conformed with previously established standards for normal controls. No significant differences were found either for insulin or growth hormone at any of the testing periods between all age groups or between the sexes. Insulin values reached their peak sixty minutes after ingestion of glucose and returned toward fasting levels at 180 min. The highest level of growth hormone was the fasting value. A decrease occurred after administration of oral glucose with a rising trend at the 180 min. testing period. Five control children who received a nonglucose-containing vehicle orally showed no statistically significant changes in growth hormone values due to the stress of multiple finger sticks.

Carbohydrate metabolism in children: (1) Blood sugar, serum insulin, and growth hormone during oral glucose tolerance tests; (2) Blood sugar during the cortisone glucose tolerance test

Oral glucose tolerance tests have been performed on 159 children 1 wk to 12 yr of age, using capillary specimens. Mean glucose responses varied only between the 112–3-yr age group and the 3–12-yr group at 60 min post-glucose ingestion. There were no agerelated differences in insulin and growth hormone responses. Cortisone glucose tolerance tests have been carried out with 113 normal children without a family history of diabetes, and the data analyzed by age group (112 yr-<4 yr, 4-<8 yr, 8–12 yr). The responses of the youngest group differed significantly from those of children older than 4 yr. There were no significant sex differences. The responses of the children 4–12 yr of age provide standards for this test.

Effect of erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) deficiency on light-induced riboflavin deficiency in the neonate.

Summary Five neonates with moderate hyperbilirubinemia and G-6-PD deficiency underwent phototherapy for periods of 48 to 120 hr. No biochemical evidence of ribo-flavin deficiency resulted. This contrasts with evidence of riboflavin deficiency observed in 15 of 16 infants with moderate hyperbilirubinemia but no G-6-PD deficiency who were exposed to light for periods of 48 hr or longer. The elevated FAD levels of the erythrocyte of the G-6-PD-deficient infants may have protected them from the light-induced vitamin deficiency.

Deterioration of tolerance to glucose and progression of the microangiopathy: effect of treatment (preliminary report).

Publisher Summary This chapter describes a study in which muscle biopsies were performed in 96 subjects divided into five groups. Twenty-five were normal control subjects with normal tolerance to glucose and no family history of diabetes. Thirty-two were prediabetics with normal tolerance to glucose and family histories ranging from both parents to only one relative having overt diabetes. It was found that when the mean basement membrane width (BMW) of the 25 normal control subjects was compared with the mean BMW of the 32 genetic prediabetics, no difference was found between the two groups. This also applied when sexes were compared. When prediabetics were matched with normal control subjects according to age, six prediabetics were found to have BMWs above 2 SD of the mean for the control group of the same age. Two had glucose areas above the mean + 1 SD of control subjects, and two had elevated insulin areas. When regression analyses were made of the data from the prediabetic and chemical diabetic groups, no significant correlation was found between BMW and glucose values.

Capillary Blood Sugar Values in Infants and Children During Oral Glucose Tolerance Tests

A capillary blood micro technic for blood sugar utilizing the Unopette, a device forobtaining the required specimens, is described. The accuracy of the Unopette was tested and established. Three-hour capillary blood oral glucose tolerance tests, using this methodology, were performed on a total of 159 children in three age groups; one week to one-and-one-half years, one-and-one-half to three years, and three to twelve years. Oral glucose solution was administered according to age and weight. All children had negative family histories for diabetes and were in good health. The mean blood sugar values for each of the three age groups were compared with one another for each of the sampling periods. No significant differences at the 5 per cent level were observed among the group means at any of the six testing periods. Over-all means and the values of ± 2 standard deviations and the third to ninety-seventh percentiles were determined for the three age groups combined. Values for the :± 2 standard deviation range were: Fasting (55 to 88 mg./ 100 ml.); thirty minutes (77 to 160 mg./100 ml.); sixty minutes (66 to 149 mg./100 ml.); ninety minutes (68 to 133 mg./100 ml.); 120 minutes (59 to 130 mg./100 ml.); 180 minutes (46 to 105 mg./100 ml.).