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Biomedical subjects

W B Pittard

Publications and source records attributed to W B Pittard.

At least 37 records · Page 2Linked to original sources
PubMed1988

Correlation of bone mineralization in the radius and humerus of well premature neonates over the first 4 months of life.

To determine how well mineralization correlates in the radius and humerus of neonates, we have measured with photon absorptiometry the bone mineral content (BMC) and bone width (BW) in the humerus and radius of well premature neonates and in the radius alone of well term neonates at birth, 8 and 16 weeks of age. These data allow (1) the correlation of bone mineralization in the humerus and radius at birth and over the first 4 months of life and (2) the correlation between bone mineralization in the radius or humerus at birth and that measured at 8 and 16 weeks in the same bone site. The BMC of the radius was significantly (P less than 0.02) correlated with the BMC of the humerus at birth, 8 and 16 weeks, but the BW of the radius was significantly correlated with the BW of the humerus only at 16 weeks. On the other hand, the BMC of the radius at birth in both term and premature neonates failed to correlate significantly (P = ns) with the BMC of the radius at 8 or 16 weeks. In the humerus, the BMC at birth was significantly (P less than 0.001) correlated with that measured at 8 but not at 16 weeks. These data indicate that the humerus and radius increase in mineral content at a similar rate over the first 4 months of life but that one cannot accurately predict from the BMC at birth what the bone mineral content will be at 8 and 16 weeks of age.

Aging↗
PubMed1988

Newborn hospitalization: a closer look.

To assess the safety of moderately early hospital discharge for normal newborn infants (mean +/- SD, 31 +/- 5 hours after delivery), we compared the incidence of hospital readmission within 6 weeks of birth with the incidence of readmission among a similar cohort of infants with extended hospitalization (mean +/- SD, 92 +/- 44 hours) as a result of maternal illness. The hospital charts for all infants admitted to the well-baby nursery between January 1 and December 31, 1985, were reviewed. Fifty-two (3.0%) of the 1714 infants who were discharged moderately early and 17 (2.7%) of the 622 infants who had an extended hospitalization were readmitted to the hospital by age 6 weeks (P = NS). Maternal age, financial status, and race each failed to predict infant readmission. Only four of the 52 readmission diagnoses among infants discharged moderately early could potentially have been identified (not prevented) before discharge with an extended newborn hospitalization. These data indicate that moderately early neonatal hospital discharge does not result in an increased incidence of rehospitalization within the first 6 weeks of life.

Bilirubin↗
PubMed1988

Stool water loss in very-low-birth-weight neonates.

Fluid requirements in very-low-birth-weight (VLBW) infants include compensation for renal, insensible (skin and lung), and stool losses and provision for fluid retained for growth. Current estimates of stool water losses in VLBW infants are based on measurements established in term neonates. Therefore, the water content of 24-hour stool collections were determined in 11 healthy VLBW male infants on full enteral feeds and compared to the working norms. The neonates in this study were less than 2 weeks old with a mean +/- SD birth weight and gestational age of 1,311 +/- 112 g and 30.8 +/- 1.5 weeks, respectively. They were receiving only enteral formula feedings of 100 ml/kg/day or more with no parenteral fluid supplementation. The mean +/- SD number of stools and water content of the stools was 2.7 +/- 2.0/day and 7.2 +/- 4.0 ml/kg/day, respectively. There was a significant correlation (r = 0.696, p less than 0.02) between gestational age at birth and number of stools per day, but the correlation between stool water loss per day, gestational age, volume of feedings per day, and birthweight was not significant. Based on this study, 7 ml/kg/day is a reasonable estimate of daily stool water loss in VLBW babies.

Feces↗
PubMed1988

Dietary assessment of maternal vitamin D intake and correlation with maternal and neonatal serum vitamin D concentrations at delivery.

Maternal and cord blood 25-hydroxy vitamin D concentrations are positively and significantly correlated. If an easily obtainable maternal dietary history could be used to predict maternal and secondarily cord blood vitamin D status, it would be a useful means of assessing the vitamin D adequacy of the newborn. Therefore, a single assessment of maternal dietary vitamin D intake during the last trimester of pregnancy was correlated with maternal and newborn serum vitamin D concentration. Neither the correlation between maternal dietary history of vitamin D intake and maternal serum 25-hydroxy vitamin D level nor between maternal dietary history and cord blood 25-hydroxy vitamin D level was significant. These data indicate that a single maternal dietary history is an inadequate method of predicting neonatal vitamin status at delivery.

25-Hydroxyvitamin D 2↗
PubMed1987

Pregnancy outcome in mothers with cystic fibrosis: normal neonatal immune responses.

Although pregnancy with cystic fibrosis (CF) has been associated in previous reports with increased maternal and neonatal morbidity, this may not reflect the current outcome with intense perinatal medical support. This report describes the pregnancy and pregnancy outcome in four women with CF. Although one neonate was delivered prematurely to a mother with advanced CF, there were no developmental abnormalities. The one premature infant was appropriately developed for his gestational age. Maternal pulmonary function was not clearly influenced by pregnancy, as confirmed by similar Schwachman scores before conception and after delivery. Finally, in this series of patients the postdelivery Schwachman score could be predicted from the preconception score.

Adolescent↗
PubMed1987

Mean platelet volume and platelet distribution width in the neonate.

Normal values for mean platelet volume (MPV) and platelet distribution width (PDW) have not been firmly established for term and preterm neonates. Cord blood samples from 143 healthy newborns (78 full term and 65 premature) were analyzed with the Coulter counter. Platelet count and MPV were significantly greater (p less than 0.05 and p less than 0.001, respectively) in term versus preterm infants, while PDW was significantly less in term infants (p less than 0.001). Platelet count and MPV correlated with gestational age, and platelet count also correlated with birth weight. There was a significant (p less than 0.001) negative correlation of PDW with gestational age and birth weight. These data represent normal reference ranges for neonates and demonstrate significant variation with gestational age.

Blood Platelets↗
PubMed1986

Relationships among vitamin D, 25-hydroxyvitamin D, and vitamin D-binding protein concentrations in the plasma and milk of human subjects.

We measured plasma and milk concentrations of vitamin D2, vitamin D3, 25-hydroxyvitamin D2 (25OHD2), 25-hydroxyvitamin D3 (25OHD3), and vitamin D-binding protein (DBP) in a group of lactating women. All vitamin D compounds were quantitated using competitive protein binding assay, while DBP concentrations were determined by rocket electrophoresis. Vitamin D3 was the most abundant vitamin D compound in human milk, followed by vitamin D2, 25OHD3, and, finally, 25OHD2. The average vitamin D activity in milk was between 33-68 IU/liter, depending on the criterion of biological activity used. DBP concentrations in milk were approximately 3% of those in plasma. Significant relationships were found between plasma and milk levels for all vitamin D compounds. The milk to blood concentration ratio was greatest for vitamin D2, followed by vitamin D3, 25OHD2, and 25OHD3. (Thus, the parent compounds gained access into milk in a much more efficient fashion than their 25-hydroxy metabolites. It is postulated that this differential translocation is controlled by the DBP in the circulation.) There was no significant correlation between plasma and milk DBP concentrations, nor were milk DBP concentrations related to the vitamin D content of milk. This investigation supports the concept that the nutritional status of lactating mothers affects the vitamin D sterol potential of her milk which, in turn, would likely have an effect on the vitamin D status of her nursing infant.

25-Hydroxyvitamin D 2↗
PubMed1985

Frequency of milk expression and milk production by mothers of nonnursing premature neonates.

The relationship between frequency of expression and milk output was studied in 25 healthy mothers of premature infants with gestational ages at birth of 28 to 37 weeks. Mothers expressed milk from days 5 to 11 post partum based on card selection, either four or more times per day or three or less times per day using an electric pump. Based on a second card selection, milk expression was either maintained at the same frequency or changed to the opposite frequency for a second week. On days 11 and 18, all milk expressed was quantitated. Of the 25 mothers studied, nine mothers changed expression frequency from four or more times per day to three or less times per day or vice versa, while nine expressed at the same frequency both weeks. These data indicate that frequent expression was associated with a significantly greater milk production (342 +/- 229 mL) than infrequent expression (221 +/- 141 mL). Thus, a low-cost, noninvasive method of enhancing milk production by mothers of nonnursing, prematurely delivered infants was to encourage frequent milk expression.

Adult↗
PubMed1985

Bacteriostatic qualities of human milk.

A practical concern of the working mother is the bacteriostatic quality of human milk over time without benefit of refrigeration. Therefore, quantitative cultures of human milk stored at room temperature were performed at 0, 2, 4, 6, and 24 hours after expression. Milk from 10 mothers less than six days postpartum (colostrum) and from 10 mothers 7 to 42 weeks postpartum (mature milk) was studied. The number of colony-forming units per milliliter of milk cultured at 0 time did not significantly increase in mature milk after 6 hours nor in colostrum after 24 hours of storage at room temperature. Thus, mothers who express milk for their own infants while at work may assume that the bacterial contamination of their milk will not increase significantly for up to but no longer than 6 hours after expression, even if they have no access to refrigeration.

Adult↗
PubMed1985

Perinatal influences on in vitro B lymphocyte differentiation in human neonates.

In vitro differentiation of B lymphocytes present in cord blood mononuclear cell preparations into immunoglobulin secreting cells was studied in 126 neonates with gestational ages (GA) ranging from 20 to 44 wk. Eight infants had a GA less than 27.9 wk, 24 had GA 28-32.9 wk, 30 had GA 33-37.9 wk, 51 had GA 38-41.9 wk, and 13 had GA above 42 wk. B cell differentiation in response to pokeweed mitogen plus hydrocortisone was assessed using a plaque forming cell assay. All neonates had a measurable plaque-forming cell response in this assay. An increased plaque-forming cell response was observed in some neonates in all gestational age groups. The magnitude of in vitro neonatal B cell differentiation underwent a continuous and significant (p less than 0.002) reduction as gestational age increased. The influence of intrauterine growth retardation on in vitro B lymphocyte differentiation was studied and compared to gestational age-matched controls with a normal intrauterine growth. Intrauterine growth retardation was not associated with changes in B cell responsiveness. An analysis of perinatal factors revealed that cesarean section, and low 1-min Apgar scores were factors that predisposed cord blood cells to be triggered in vitro to produce increased numbers of plaque-forming cells.

Apgar Score↗
PubMed1985

Vitamin E and C concentrations in human milk with maternal megadosing: a case report.

Vitamins C and E were selected for analysis in this patient to study the effect of megavitamin ingestion on water-soluble and milk-fat-soluble vitamin concentration. This mother also had chronically consumed megadose amounts of vitamins A, B-6, B-12, and thiamin. Although these vitamins were not quantitated in her milk, one would anticipate that they were elevated, as were vitamins C and E. Long-term megavitamin intake of vitamins C and E, 40 and 99 times the RDAs, respectively, was associated with elevated blood and milk vitamin levels. The thesis that dietary water-soluble but not fat-soluble vitamins alter milk vitamin concentrations was not supported. Milk vitamin C levels were elevated above established norms, and milk vitamin E levels were more than three times the upper range of normal.

Adult↗
PubMed1984

Normal lymphocyte responses to mitogens in term and premature neonates following normal and abnormal intrauterine growth.

Cord blood lymphocyte responses to a panel of four mitogens were studied in 242 neonates using a whole blood technique. The patient population was divided into five gestational-age groups: 20-27.9, 28-32.9, 33-37.9, 38-41.9, and 42-44 weeks. Neonatal lymphocytes undergo a continuous reduction in proliferative responsiveness to the polyclonal ligands phytohemagglutinin (PHA) and concanavalin A (Con A) as gestation progresses from 20 to 44 weeks postconception. This is consistent with their change in unstimulated in vitro blastogenesis which when measured over the same developmental period is greatest in more immature neonates. Neonatal lymphocyte proliferative responsiveness to pokeweed mitogen (PWM) and staphylococcus protein A (SpA), however, was unrelated to gestational age. The influence of intrauterine nutritional deprivation on lymphocyte proliferative responses was studied in clinically uninfected newborns and compared to gestational age-matched controls with a normal nutritional status. Intrauterine nutritional deprivation was not associated with a decrease in mitogen-induced lymphocyte proliferation. Further, we explored the influence of several perinatal clinical settings commonly associated with fetal distress on cord blood lymphocyte responses to mitogens. Although perinatal stress in the form of low Apgar scores, meconium-stained amniotic fluid, and prolonged rupture of the amniotic membranes was not related to differences in mitogen induced lymphocyte proliferation, mode of delivery was. Cesarean section delivery as compared to vaginal delivery was associated with a significantly greater PHA-, Con A-, and SpA-induced neonatal lymphocyte response. Several alternative explanations for this finding are explored. Lastly, the purified protein thymosin fraction 5 was not associated with alteration in either neonatal or adult mitogen-induced lymphocyte proliferation.

Adolescent↗
PubMed1984

Evaluation of the total fetomaternal vitamin D relationships at term: evidence for racial differences.

The present study assessed the total fetomaternal vitamin D relationship at term in 12 white and 10 black mothers and their infants. Antirachitic sterols were extracted from plasma, chromatographed, and finally quantitated using competitive protein binding assays. Compounds quantitated included vitamins D2 and D3, 25-hydroxyvitamin D2, 25-hydroxyvitamin D3, 24,25-dihydroxyvitamin D2, 24,25-dihydroxyvitamin D3, 25,26-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D2, and 1,25-dihydroxyvitamin D3. There was a strong correlation between maternal and neonatal plasma concentrations of all antirachitic sterols measured with the exception of vitamins D2 and D3. Vitamins D2 and D3, although detectable in maternal plasma, were undetectable in neonatal plasma. Racial comparisons demonstrated that vitamin D3, 25-hydroxyvitamin D3, 24,25-hydroxyvitamin D3, and 25,26-(OH)2-D3 were significantly (P less than 0.05) higher in white than in black mothers. Total 25-hydroxyvitamin D and 24,25-hydroxyvitamin D were also significantly (P less than 0.05) higher in white than in black mothers. A similar pattern was found in black and white infants except for 25,26-(OH)2-D3. Black mothers and their infants had significantly (P less than 0.05) higher 1,25-hydroxyvitamin D3 compared to the white subjects, although total 1,25-hydroxyvitamin D was not different between races. No significant racial (P greater than 0.05) differences were found for any of the vitamin D2 compounds. The results support the concept that fetomaternal vitamin D status are intimately related. Further, they strongly suggest that fetal metabolism begins with 25-hydroxyvitamin D rather than vitamin D. Finally, racial factors appear to influence the overall vitamin D status of both mother and fetus, and may influence antirachitic sterol metabolism.

25-Hydroxyvitamin D 2↗
PubMed1984

Cord blood B cell differentiation. Synergistic effect of pokeweed mitogen and Staphylococcus aureus on in vitro differentiation of B cells from human neonates.

B lymphocyte differentiation into immunoglobulin secreting cells is a process depending on the presence of functionally mature B lymphocytes, monocytes and regulatory T lymphocytes. Cord blood B lymphocytes present in isolated cord blood mononuclear cell (MNC) preparations are normally unable to differentiate into immunoglobulin secreting plaque forming cells (PFC) when cultured in the presence of pokeweed mitogen (PWM) alone or killed Staphylococcus aureus Cowan 1 (SAC1) alone. However, each one of these activators induces PFC formation by B lymphocytes in adult MNC cultures. In the present study we show that these two activators can act synergistically to induce a significant in vitro PFC response in cord blood MNC's. The synergism of PWM and SAC1 exhibits a requirement for a specific sequence of addition in order to induce a positive response in neonatal cells. If both activators are not added simultaneously at the initiation of culture, only the initial addition of SAC1 followed by PWM will result in increased PFC production. The action of PWM and SAC1 on cord blood MNC can each be replaced by conditioned media. Supernatants from monocyte cultures containing soluble factors such as interleukin-1 (IL-1) can substitute for the activity of SAC1 while supernatants containing soluble T-cell factors (interleukin-2[IL-2], T cell replacing factor (TRF), B cell differentiation factor (BCDF), etc) can replace PWM in the cord blood MNC cultures. The results suggest that the synergistic effect of these two activators overcomes a partial immaturity or an excessive suppressor activity of human cord blood MNC.

Adult↗