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Biomedical subjects

W Oh

Publications and source records attributed to W Oh.

At least 235 records · Page 13Linked to original sources
PubMed1981

Effects of acidosis on the activity of creatine phosphokinase and its isoenzymes in the serum of newborn infants.

The total creatine phosphokinase (CPK) activity and the levels of activity of its MM, MB and BB isoenzymes were measured in sera obtained within four hours after birth from 32 newborn infants. The total CPK level and activity of its MM, MB, and BB isoenzymes increased significantly with increasing acidosis. In addition, statistically significant correlations were found between the total CPK level in infants' sera and their one-minute Apgar scores. The infants' birth weight, gestational age, and mode of delivery did not correlate significantly with the serum total CPK activity. Infants who died within ten days after birth from causes related to asphyxia had significantly higher total CPK activity levels in their sera in comparison with the survivors. The data suggest that perinatal asphyxia with acidosis may result in the leakage of CPK and its isoenzymes from the damaged cells into the circulation and that a marked elevation of their values may indicate a poor prognosis for survival.

Acidosis↗
PubMed1980

Glycohemoglobin in diabetic pregnancy: a sequential study.

Glycohemoglobin (Hb Alc) was assayed sequentially during pregnancy and post partum in 53 women. In a group of nondiabetic women (N = 13) Hb Alc fell significantly (p less than 0.001) from the first to the third trimester and then rose to first-trimester levels by 12 weeks' post partum. Glycohemoglobin levels of insulin-dependent diabetic patients (N = 28) followed a similar pattern but at significantly elevated levels compared to nondiabetic patients (p less than 0.001). In contrast, patients with chemical diabetes (N = 12) did not manifest any change of Hb Alc with time, although they did have glycohemoglobin levels above those of the normal subjects during the third trimester (p less than 0.001) and before 12 weeks' post partum (p less than 0.02). It is speculated that these fluctuations in Hb Alc are most likely due to changes in long-term blood glucose control. Additionally, because Hb Alc increased in vitro oxygen affinity, some of these women were followed for parameters of oxygen transport as well. No significant changes of parameters of oxygen transport were found, with the exceptions of P50 in vivo and P50pH7.40 during the third trimester and of P50 in vivo before 12 weeks' post partum

Blood Glucose↗
PubMed1980

Effect of fluid administration on the development of symptomatic patent ductus arteriosus and congestive heart failure in premature infants.

We studied 170 premature infants with birth weights between 751 and 2000 g in a randomized sequential trial comparing "high" and "low" volumes of fluid intake. Beginning on the third day of life, the low-volume group received only enough water to meet average estimated requirements, and the high-volume group received an excess of at least 20 ml per kilogram of body weight per day (mean excess, 47 ml per kilogram per day). Sequential analysis showed that the risk of patent ductus arteriosus with congestive heart failure was greater in infants receiving the high-volume regimen. Thirty-five of 85 infants in the high-volume group acquired murmurs consistent with patent ductus arteriosus, and 11 of these 35 had congestive heart failure. Only nine of 85 infants in the low-volume group had murmurs consistent with patent ductus arteriosus, and two of these nine had congestive heart failure. More cases of necrotizing enterocolitis also occurred in the high-volume group. We conclude that limitation of fluid intake to amounts estimated to meet requirements for excretion, insensible loss, and growth can reduce the risks of patent ductus arteriosus and congestive heart failure in premature infants.

Ductus Arteriosus, Patent↗
PubMed1980

Nonketotic hyperglycinemia. Effects of therapy with strychnine.

Nonketotic hyperglycinemia was diagnosed in identical twins with lethargy and respiratory failure in the neonatal period. Therapy with strychnine (0.32 mg/kg/day) resulted in great reductions in CSF and plasma glycine levels and improvement in muscle tone, respiration, and ability to suck. Myoclonic seizures were partially controlled by therapy with clonazepam. Higher dosages of strychnine (up to 2.0 mg/kg/day) were needed to counteract the increased lethargy following administration of clonazepam. At 5 months of age, the twins' developmental performance remained below the 1-month level despite adequate somatic growth. The twins died suddenly of status epilepticus at 6 1/2 months of age.

Amino Acid Metabolism, Inborn Errors↗
PubMed1980

Somatic growth of children of diabetic mothers with reference to birth size.

In this study of the effects of maternal diabetes on the growth of offspring, 52 diabetic mothers were enrolled prenatally in the Providence cohort of the Perinatal Collaborative Study during 1960-1963. Among the offspring, there were 12 perinatal deaths. We were able to enroll 34 survivors and 34 matched controls in an adolescent follow-up study. Of the 34 diabetic mothers, six were insulin dependent, six had chemical diabetes, 13 had gestational diabetes, and nine were suspects. As part of the Collaborative Project, sequential follow-up evaluations had been done at four months, one year, four years, and seven years. A positive relationship was found between maternal pre-pregnant weight, weight gain during pregnancy, and the neonatal weight/height index in both diabetic and control subjects. At 7 years of age, eight of 19 offspring of diabetic mothers who were large for gestation at birth were obese, whereas only one of 14 infants who were appropriate for gestation at birth were obese (P < 0.05). Adolescent obesity (weight/height index greater than or equal to 1.2) was more likely in infants who had been LGA at birth. These data suggest that macrosomia in infants of diabetic mothers may be a predisposing factor for later obesity.

Adolescent↗
PubMed1980

The effects of thermal environment on heat balance and insensible water loss in low-birth-weight infants.

To define the neutral environmental temperature and assess the effects of deviation from that temperature on insensible water loss and heat balance, 12 premature infants were studied in a conventional incubator at four different predetermined ambient temperatures. Our method combines insensible water loss measured by a continuous read-out electronic scale with heat production as determined by open circuit measurement of oxygen consumption. An increase of 1 to 2 degrees C, to an ambient temperature above or near the top of the neutral zone, produced a significant rise in insensible water loss, from 1.90 +/- 0.76 to 3.08 +/- 1.19 ml/kg/hour (mean +/- SD), a corresponding rise in evaporative heat loss, and a fall in nonevaporative heat loss. A decrease of 1 to 2 degrees C, to a slightly subneutral ambient temperature, resulted in an increase in oxygen consumption from 5.82 +/- 0.92 to 7.45 +/- 1.50 ml/kg/minute, and an increase in total heat loss, but no change in insensible water loss and evaporative heat loss. The increased total heat loss was judged to be due entirely to a greater nonevaporative heat loss, both by convection and by radiation. The data confirm that ambient temperature is an important determinant of the magnitude and the partition of heat loss in low-birth-weight infants.

Body Temperature Regulation↗
PubMed1980

Heat balance in premature infants: comparative effects of convectively heated incubator and radiant warmer, with without plastic heat shield.

Insensible water loss, oxygen consumption, and carbon dioxide production were measured in eight premature infants under four different conditions: in conventional single-walled incubator with and without plastic heat shield, and under radiant warmer with and without heat shield. IWL was greater under the radiant warmer (3.40 +/- 1.50 ml/kg/hour, mean +/- SD) than in the incubator (2.37 +/- 1.15 ml/kg/hour) when both were compared without heat shield. Addition of the heat shield reduced IWL in the incubator (2.13 +/- 0.76 ml/kg/hour) but not under the radiant warmer (3.37 +/- 0.94 ml/kg/hour). There were no significant differences in VO2 or respiratory quotient between any two of the four study conditions.

Body Temperature Regulation↗
PubMed1980

Hyperviscosity in the small-for-gestational age infant.

Small-for-gestational age infants are prone to hyperviscosity but the precise incidence in unknown. A prospective survey was conducted on 4,974 consecutive livebirths for hyperviscosity in small-for-gestational age infants. Small-for-gestational age is defined as birth weight below the 10th percentile of the intrauterine growth curve and signs of malnutrition and hyperviscosity as venous blood viscosity (measured by a microviscometer) above the 2 SD of the norm. 79 infants were identified as small-for-gestational age. Of these, 14 were hyperviscous and 65 were normoviscous. The venous hematocrit range from 61 to 70% in hyperviscous and 37 to 62% for normoviscous. A predefined symptom complex referrable to cardiovascular, respiratory, gastrointestinal, and central nervous system were assessed by an unbiased observer; 57% of hyperviscous and 25% of normal viscous infants were symptomatic (p less than 0.05 by chi 2). The data indicate that the hyperviscosity syndrome occurs in 17.7% of small-for-gestational age infants; venous hematocrit (64%) is predictive of hyperviscosity, and that in spite of a positive correlation between symptom complex and hyperviscosity, there is a lack of specificity for the clinical manifestation of this neonatal complication.

Birth Weight↗
PubMed1980

Glycosylation and acetylation of hemoglobin in infants of normal and diabetic mothers.

The minor hemoglobins, which are formed post-translationally by acetylation or glycosylation, were studied in cord blood from 34 newborn infants. There were 9 normal infants, 8 infants of gestational (chemical) diabetics, and 17 infants of insulin-dependent diabetics. Among these groups, no significant differences in the acetylated fetal (FI) or other minor hemoglobin fractions were found by either isoelectric focusing in polyacrylamide gels or chromatography on DEAE-cellulose columns. These studies emphasize the technical limitations of detecting small amounts of glycosylated hemoglobin in newborns. The biological implications of the acetylated fetal hemoglobin fraction remain obscure.

Acetylation↗
PubMed1980

Glucose perturbation in experimental hyperviscosity.

Hyperviscosity was produced in one member of each of 7 sets of twin newborn lambs by an exchange transfusion with 500 ml maternal packed red blood cells. The remaining seven control twin lambs underwent an identical exchange with maternal whole blood. Postexchange hematocrits were 63 +/- 6 and 29.0 +/- 3% (mean +/- S.E.), respectively (P less than 0.01). Whole blood viscosity measured at 3 rpm increased from 3.2 +/- 0.4 centipoise (cps) to 14.4 +/- 6.1 cps in the lambs made hyperviscous (P less than 0.01) and remained unchanged in the control lambs (2.2 +/- 0.1 versus 2.8 +/- 0.3 cps). A 2-hr steady state glucose infusion was performed on each lamb before and after the packed cell or whole blood exchange transfusion. Mean steady state plasma glucose concentrations were significantly decreased from pre-exchange steady state glucose infusion levels in the same lambs made hyperviscous (P less than 0.05), whereas steady state glucose levels increased from preexchange levels in the twin lambs exchanges with maternal whole blood. Mean plasma insulin and glucagon values for the hyperviscous and control lambs remained unchanged during the glucose infusion.

Animals↗
PubMed1980

Endogenous posthepatic insulin secretion and metabolic clearance rates in the neonatal lamb.

Posthepatic insulin availability has been evaluated by steady-state insulin turnover studies with 131I-insulin. Spontaneously delivered term (age 3.3 +/- 0.8 days) (mean +/- S.E.) and prematurely delivered lambs (betamathasone treated at 132 days) (age, 1.1 +/- 0.2 days) were compared with 4- to 5-month-old sheep. After a 7-hr fast, animals received 0.45% saline or 5.7 mg/kg/min glucose (0.06 ml/kg/min) for 6-hr followed by the tracer insulin infusion for 110 min. Plasma glucose, insulin, and immunoprecipitable insulin were measured sequentially during the steady state. Endogenous posthepatic insulin secretion and metabolic clearance rates were derived. Neither endogenous posthepatic insulin secretion rates nor metabolic clearance rates were different among the three groups of animals when either 0.45% saline or 5.7 mg/kg/min exogenous glucose infusions were compared. Secretory response of the pancreatic beta cell to continuous glucose infusion seems similar for the term and preterm lamb when compared to adult sheep.

Aging↗
PubMed1980

Pharmacokinetics and echocardiographic effects of digoxin in low birth weight infants with left-to-right shunting due to patent ductus arteriosus.

Serum digoxin (DIG) levels, timed urine and M-mode echocardiograms were performed in 9 low birth weight infants with left-to-right shunting due to patent ductus arteriosus treated with DIG (40 micrograms/kg in 3 and 20 micrograms/kg in 6). Half the DIG was given initially and a quarter at 8-hourly intervals. Serum DIG levels at 24 h (1.8-7.0 ng/ml) were similar in both dose groups. One infant in the 40 micrograms/kg dose group developed Wenckebach phenomenon. Left atrial to aortic root ratio fell within 30 min and remained reduced during the ensuing 24 h (p less than 0.025). There were no significant changes in the other echocardiographic measurements. Half-life of distribution and elimination of DIG were 1.04 +/- 0.46 and 15.25 +/- 0.36 h. The alpha-phase volumes of distribution (VD) differed between the 40 and 20 micrograms/kg dose groups (2.28 +/- 0.05 vs. 1.33 +/- 0.66 liters/kg, p less than 0.025). The beta-phase VD (4.25 +/- 0.61 and 2.76 +/- 0.99, respectively) were similar. Mean urinary DIG clearance was 13.1 +/- 3.2 ml/min/1.73(2).

Digoxin↗
PubMed1980

Rapid fluorometric assay of bilirubin and bilirubin binding capacity in blood of jaundiced neonates: comparisons with other methods.

The concentrations of total blood bilirubin, albumin-bound bilirubin, and the reserve and total bilirubin binding capacities of 35 neonatal blood samples (28 patients) were determined by automated front-face fluorometry ((hematofluorometer). These values were compared to results of diazo determinations, Sephadex gel filtration, and peroxidase-oxidation methods. Total blood bilirubin level by fluorometry agreed well with the total plasma bilirubin level by diazotization (r = .96, sigma = 1.7 mg/100 ml). Albumin-bound bilirubin concentrations by fluorometry also correlated well with diazo values (r = .95, sigma = 1.9 mg/100 ml) and were slightly lower than the total blood bilirubin concentrations. Values for total bilirubin binding capacity determined by fluorometry agreed well with results obtained for the same specimens by Sephadex gel filtration (n = 28, r = .97, sigma = 1.8 mg/100 ml) and by peroxidase-catalyzed oxidation (n = 25, r = .97, sigma = 1.7 mg/100 ml). The agreement among the results obtained by the three methods indicates a well-defined in vitro end point at which available primary or "tight" binding sites on albumin are saturated with bilirubin. In this clinical experience the coefficient of variation of results with the hematofluorometer was 8.4% for total blood bilirubin and 6.5% for total binding capacity. A comparison of "sick" with "well" infants revealed that the fraction of bilirubin not bound to albumin was significantly different for these two groups. The assays made with the hematofluorometer are quick (10 to 15 minutes) and require only a small quantity (approximately 150 microliters) of blood.

Bilirubin↗