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Biomedical subjects

R K Whyte

Publications and source records attributed to R K Whyte.

27 records · Page 2Linked to original sources
PubMed1985

Energy intake and the nature of growth in low birth weight infants.

Growth is accompanied by and depends on energy storage in growing tissue. The rate of energy storage in growing low birth weight infants depends on the rate of energy intake and on the rates of energy excretion and expenditure, both of which (on a body weight basis) are much higher than in adults, and both of which increase with increments of gross energy intake. Energy-balance studies of growing low birth weight infants on gross energy intakes approximating 500 kJ X kg-1 X d-1 of mothers' milk or of infant formula indicate that the composition of extrauterine weight gain of the low birth weight infant differs from that of the fetus of similar gestation, in that the energy storage cost of growth is much higher. Attempts to increase metabolizable energy intake beyond 500 kJ X kg-1 X d-1 by energy supplementation alone do not result in proportionately increased rates of weight gain; low birth weight formulae, in which energy, protein, and mineral contents are all increased can result in large weight gains with proportionate increases in rates of protein and fat accretion.

Body Temperature↗
PubMed1983

The inflammatory response in candidal chorioamnionitis.

Fetal infection with Candida organisms has not commonly been reported. Umbilical cords and placentas from 23 cases of chorioamnionitis collected over a nine-year period were examined by electron microscopy and immunoperoxidase staining. Gross features, especially of the umbilical cord, were distinctive and included the pale yellow plaques pathognomonic of candidal funisitis. Histopathologically, the lesions were found to be focal and subamniotic and were often embedded in a "fibrinoid" exudate and surrounded by inflammatory cells. In some cases the exudate and inflammatory cells were deposited in dense bands. Immunoperoxidase staining showed the lesions to contain IgG, IgM, and IgA, which probably originated in dense-staining plasmacytoid and immunoblastic cells in the inflammatory infiltrates. Additional findings in two fetal cases of giant cell pneumonitis suggested that the fetus can mount a brisk inflammatory and immune response to Candida organisms as early as 18 weeks' gestation and that mucosal exposure to this antigen can result in production of IgA by the lung.

Candidiasis↗
PubMed1983

Energy balance and nitrogen balance in growing low birthweight infants fed human milk or formula.

Energy and nitrogen balances were measured in growing low birthweight infants fed either mother's expressed breast milk or a 20 kcal per ounce formula to determine whether or not there were differences between the two dietary groups in (1) the partition of energy among excretion, expenditure, and storage and (2) the relation of energy storage and nitrogen retention to weight gain. There were no significant differences between the human milk fed infants and formula fed infants in gross energy intake, metabolizable energy intake, nitrogen intake, or nitrogen retention. Energy expenditure was significantly lower in the human milk fed infants than in formula fed infants (221 kJ/(kg. day) and 244 kJ/(kg. day), respectively). There was no difference in mean energy storage between the two groups. Although weight gains were similar in both dietary groups, the ratio of energy storage to weight gain was significantly greater in infants fed with human milk (15.3 kJ/g, S.D. 2.0) than in infants fed formula (13.2 kJ/g S.D. 1.8). There was no significant difference between the two groups in the ratio of nitrogen stored to weight gain.

Body Weight↗
PubMed1982

Antenatal infections with Candida species.

The clinical, pathological, and microbiological features of 18 pregnancies complicated by intrauterine infection with Candida sp. are described. Chorioamnionitis with Candida sp. can be recognised macroscopically at birth. Penetration of the umbilical cord and membranes is associated with an intense fetal inflammatory response. The infection characteristically presents in infants of very low birthweight as pneumonia or a skin infection. In nearly every case the organism can be recovered from the gastric aspirate. A case control study showed that there is a striking association between chorioamnionitis caused by Candida sp. and the presence of a foreign body (an intrauterine contraceptive device or a cervical suture) in the mother's genital tract in pregnancy. This feature in the perinatal history of an infant of short gestation who exhibits a very high neutrophil count should alert the clinician to the possible presence of chorioamnionitis due to Candida sp.

Candidiasis↗
PubMed1982

Energy cost of growth of premature infants.

The objective of this paper is to review approaches to the determination of the energy cost of growth in premature infants. Two approaches are compared: one based on the composition of weight gain, and one based on the determination of energy balance. Data are lacking on the composition of weight gained by the premature infant after birth, while the composition of fetal weight gain and its energy cost can be calculated from data on fetal body composition. These calculations show that energy storage amounts to less than 8.4 kJ/g weight gain below a body weight of 2 kg; the total energy cost of growth is less than 10.5 kJ/g. Estimates twice as high have been obtained from energy balance studies of growing premature infants and older infants. We conclude that the energy cost of growth in premature infants is still uncertain and requires further study.

Body Composition↗
PubMed1978

Faecal excretion of oligosaccharides and other carbohydrates in normal neonates.

Chromatographic analysis of sugars in the stools of 40 normal newborn infants has shown the presence of an oligosaccharide in 85% of samples. The oligosaccharide has been shown to contain fucose (6-deoxygalactose), glucose, and galactose and is present in normal breast milk. In addition fucose has also been found in the presence of galactose in some samples and is probably a breakdown product of milk oligosaccharides. These findings, which affect the interpretation of faecal sugar excretion, have not been described previously.

Animals↗
PubMed1975

Assessment of Doppler ultrasound to measure systolic and diastolic blood pressures in infants and young children.

A recently developed instrument uses the Doppler shift technique to detect vessel wall movement, and it has been suggested that in conjunction with a conventional sphygmomanometer systolic and diastolic blood pressures can be measured. A controlled study was carried out in 20 children recovering from cardiac surgery where direct intra-arterial measurements (one observer) were compared with independent measurements using the Doppler instrument (2 observers). Systolic pressures measured directly and by Doppler technique correlated well and there was no significant difference between intra-arterial and indirect measurements whether the latter were taken by doctors or by nurses. In contrast, direct and indirect diastolic pressure measurements correlated poorly and were significantly overestimated with a mean difference of 6-25 mmHg (range +25 to -10) for doctors, and 4-25 mmHg (range +20 to -10) for nurses. Thus, the instrument adequately measured systolic blood pressure, but in our hands did not give precise measurements for diastolic blood pressure.

Blood Pressure Determination↗
PubMedDate not supplied

Calcium glycerophosphate as a source of calcium and phosphorus in total parenteral nutrition solutions.

Calcium glycerophosphate (CaGP) was tested as an alternative to calcium gluconate (CaGluc) and potassium mono- and dibasic phosphate (KPhos) as a source of Ca and P in total parenteral nutrition (TPN) solutions for piglets. Four-day-old piglets were infused for 7 days with a TPN solution that provided either 4.2 mmol Ca and 2.1 mmol P/kg/24 h as CaGluc and KPhos (the maximum quantities that can be provided using these sources), or 15.0 mmol Ca and 15.0 mmol P/kg/24 h as CaGP. Ca and P retentions were more than six times greater (p less than 0.01) in the piglets receiving CaGP (14.5 +/- 0.2 vs 2.2 +/- 0.3 mmol Ca/kg/24 h and 13.3 +/- 0.4 vs 2.4 +/- 0.1 mmol P/kg/24 h) (Mean +/- SEM). The ratio of Ca to fat-free dry weight, an indicator of bone mineralization, was significantly higher (p less than 0.05) in the humerus (174.8 +/- 2.2 vs 147.2 +/- 6.7) and femur (158.3 +/- 4.8 vs 130.1 +/- 7.8) in the CaGP group. This study showed that CaGP is efficiently used as a source of Ca and P in TPN solutions for piglets. The results suggest that the use of CaGP as the source of Ca and P in TPN solutions may prevent the development of the undermineralized bone seen in low-birth weight infants nourished intravenously.

Animals↗