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Biomedical subjects

J B Gould

Publications and source records attributed to J B Gould.

At least 37 records · Page 2Linked to original sources
PubMed1984

Diabetes-induced alterations of glucose metabolism in rat cerebral microvessels.

The effect of diabetes on the metabolism of glucose and lactate was examined in isolated rat cerebral microvessels. In rats with diabetes induced with streptozotocin, glucose oxidation to CO2 by the microvessels was decreased by 54-83% and its conversion to lactate by 21-61%. Insulin therapy for several days or starvation for 48 h both lowered blood glucose levels in the diabetic rats and restored microvessel glucose metabolism to normal. Cerebral microvessels consist principally of the capillaries that constitute the blood-brain barrier. Direct assessment of the blood-brain barrier in vivo using the brain uptake index (BUI) technique revealed a close parallel to the findings in the microvessels. Thus, hexose transport was diminished in diabetic rats and restored to normal by both insulin therapy and starvation. The oxidation of [1-14C]lactate to CO2 like that of glucose was depressed in microvessels of diabetic rats. In contrast to glucose, however, the transport of lactate across the blood-brain barrier in vivo was not altered. These findings suggest that diabetes suppresses glucose metabolism in rat cerebral microvessels and downregulates glucose transport across the blood-brain barrier. They also suggest that both of these processes are regulated by chronic alterations in blood glucose concentration rather than by insulin per se.

Animals↗
PubMed1982

Maternal cigarette smoking, psychoactive substance use, and infant Apgar scores.

A study of 1,709 mother/child pairs at Boston City Hospital examined whether maternal cigarette smoking, drinking, or the use of other psychoactive substances was associated with low infant Apgar scores. The potential confounding effects of other labor and delivery risks were controlled in the analysis. In contrast to previous reports, univariate and stepwise multiple regression analyses did not identify a significant negative association between cigarette smoking and 1- or 5-minute Apgar scores. None of the substance use variables was significantly associated with low infant Apgar scores at 1 and 5 minutes. Other labor and delivery risks, such as short length of gestation, abnormal delivery presentation, placental abnormalities, nuchal cord, and exposure to general anesthesia during delivery, were associated with low Apgar scores.

Adult↗
PubMed1980

Neonatal pneumopericardium: current management.

Neonatal pneumopericardium (PPC) is a frequently encountered complication of ventilator therapy. However, the appropriate management remains controversial. We describe seven infants who demonstrate the clinical spectrum of PPC. It is apparent that PPC can occur as an asymptomatic finding and may not require invasive therapy. PPC may present also with cardiac tamponade and require immediate diagnosis and therapy. Simple needle pericardiocentesis is appropriate therapy for most cases with tamponade, however a few babies with PPC uncontrolled by needle aspiration required placement of pericardial catheter for continuous drainage of the air. Mortality from PPC with tamponade (86% without therapy) should be much improved with modern management.

Cardiac Catheterization↗
PubMed1980

Factors affecting sleep spindle activity during infancy.

Sleep spindle activity was evaluated in 32 twins at 52 weeks postconceptional age. Significantly increased mature spindle activity was seen in infants born at older gestational ages, in femals, and in infants who were stressed by intra-uterine growth retardation or with mild postnatal respiratory illness.

Cerebral Cortex↗
PubMed1980

Periodic alpha seizures with apnea in a newborn.

A post-mature female newborn with a history of birth trauma developed frequent apneic spells coincident with left posterior-quadrant alpha discharges on her electro-encephalogram. Except during apneic spells, clinical seizure activity was rare. The alpha discharges occurred at regular intervals and were associated with disrupted sleep cycles and a diminution in the proportion of quiet sleep. Phenobarbital apparently abolished the apnea and alpha discharges and resulted in normal sleep cycles and state proportions. At 20 months of age the patient is neurologically and developmentally normal. She has been free of apnea and seizures since the newborn period, despite withdrawal of the anticonvulsant at eight months of age. The authors relate her favorable course to the etiology, periodicity and therapeutic response of her clinical and electrical seizures.

Alpha Rhythm↗
PubMed1980

Apnea and sleep state in infants with nasopharyngitis.

Having a mild upper respiratory tract infection does not change the sleep rate proportions or total sleep time of an infant. However, infants with colds exhibit some sleep state specific alterations in sleep apnea. At 40, 44, and 48 weeks postconception, the number of respiratory pauses of 2 to 4.9 seconds and of 5 to 9.9 seconds duration per 100 minutes of state, during rapid eye movement, and indeterminate sleep are decreased in infants with colds. The absence of this phenomenon at 52 weeks suggests that it is modified by maturation. We hypothesize that the reduction in rapid eye movement and indeterminate sleep apnea is a manifestation of an adaptive response in normal infants, but for infants at risk for the sudden infant death syndrome, this response may be overwhelmed, resulting in increased apnea and, in some instances, sudden infant death.

Diseases in Twins↗
PubMed1979

Apnea recordings of healthy infants at 40, 44, and 52 weeks postconception.

A total of 129 recordings of the respiratory activity of 46 normal full-term infants were obtained continuously for 24 hours in the hospital nursery at 3 days of life and in the home environment at 4 weeks and 12 weeks after birth. The pediatric pneumogram (PPG) technique, an impedance method, was used. Pneumogram data over longer than 16 hours was obtained on 77% of infants monitored. No infants experienced apnea longer than 15 seconds in duration at 40 and 44 weeks postconception, or greater than 11 seconds at 52 weeks postconception. Twenty-four hour plots of hourly apnea frequency revealed a marked variability, with evidence of clustering of apneic episodes during periods of reported sleep. Longest apnea time and hourly frequency of apneic episodes were highly correlated.

Apnea↗
PubMed1977

The relationship between accelerated pulmonary maturity and accelerated neurological maturity in certain chronically stressed pregnancies.

Two studies were done. In the first, 51 infants from high-risk pregnancies were evaluated for accelerated clinical neurological maturation. Eight infants had accelerated neurological maturation 3 or more weeks in excess of gestational age. In the second study, a sample of 25 infants with documented acceleration of pulmonary surfactant (lecithin/sphingomyelin ratio greater than or equal to 2 at gestational age less than or equal to 32 weeks) all infants showed accelerated neurological maturation (range 3 to 8 weeks) with the conditions studied associated with accelerated pulmonary maturation (for instance, retroplacental bleeding, prolonged rupture of membranes, placental infarction, severe toxemia, hypertensive disease, circumvallation, and amnionitis). Chronic retroplacental bleeding was associated with the most dramatic pulmonary and neurological accelerations.

Birth Weight↗
PubMed1977

The sleep state characteristics of apnea during infancy.

The sleep state characteristics of infant sleep apnea were studied in 36 twins examined by polygraphy at 40, 44, and 52 weeks after conception. The definition of sleep apnea is dependent upon the length of apnea, sleep state, and post-conceptional age. None of the infants had apnea longer than 20 seconds and apnea of 10 seconds or longer was uncommon. The attack rates for apneas 2 to 4.9 seconds long were highest in REM and lowest in qliet sleep. The attack rates for apneas 5 to 9.9 seconds long were equal in REM and indeterminate and lowest in quiet sleep. The percentage of infants with apnea of 10 seconds or longer at 40 weeks was highest in REM (27%) and indeterminate sleep (42%) and lowest in quiet sleep (12%). At 52 weeks, apnea 10 seconds or longer during REM decreased to 0%. The effect of maturation on apnea varies with sleep state. Over the period from 40 to 52 weeks, quiet sleep apnea was unchanged and indeterminate sleep apnea decreased only between 40 and 44 weeks. Although REM apnea 2 to 4.9 seconds long was unchanged, REM apnea 5 to 9.9 seconds long decreased between 40 and 44 weeks, and REM apnea of 10 seconds or longer decreased from 27% at 40 weeks to 0% at 52 weeks. This suggests that semi-independent apnea turn-on and turn-off mechanism operate during REM sleep. A correlation between brief apneas and the longer apneas was seen only during REM sleep. For all sleep states, there was no correlation between the levels of apnea of 5 seconds or longer at 40, 44, and 52 weeks.

Aging↗
PubMed1976

Central hypoventilation during quiet sleep in two infants.

Expired ventilation (VE), tidal volume (VT), frequency (f), and alveolar PCO2 (PACO2) were examined in six normal infants at 41 to 52 weeks post-conceptional age and in two infants who were apneic at birth. Their response to breathing 5% carbon dioxide in air and to 100% oxygen in quiet sleep were compared to those in rapid eye movement (REM) sleep. VE in normal infants was 259 ml/kg/min in REM and 200.2 ml/kg/min in quiet sleep with the difference being due to decreased carbon dioxide production and to decreased dead space. VE increased 34.4 ml/kg/min/mm Hg of PCO2 elevation with 5% carbon dioxide breathing during REM and was not significantly different during quiet sleep. During oxygen breathing VE fell by 32.7% at 30 seconds before increasing again. In the affected infants, VE and PACO2 during REM at 1 and 4 months were normal. At 1 month, during quiet sleep, each infant became apneic and PACO2 rose 9 and 8 mm Hg/min respectively. At this time mechanical ventilation was begun. At 4 months, during quiet sleep, VE was 0.064 and 0.063 ml/kg/min at PACO2 of 66 mm Hg in each infant. The change was due entirely to a decrease in VT to 2.3 and 2.5 ml/kg. At this time 5% carbon dioxide breathing given during normal ventilation in REM produced an abrupt fall in VT to 2.0 and 2.2 ml/kg with no change in frequency. Oxygen breathing during REM at one month had no effect but at 4 months produced apnea requiring mechanical ventilation after one minute. The findings suggest that the ventilatory response to carbon dioxide is (1) important in initiation of extrauterine ventilation and (2) in sustaining ventilation particularly in quiet sleep. It is not necessary in sustaining ventilation awake or in REM sleep and it represents a balance between the stimulatory and depressant effects of carbon dioxide on the central nervous system.

Apnea↗
PubMed1976

Familial aggregation of blood pressures of newborn infants and their mother.

The blood pressures and pulse rates of 257 normal full-term infants and their mothers were measured two to four days after birth. Birthweight was correlated with systolic (P=.038), but not with diastolic blood pressure. Infants who were asleep had significantly lower systolic and diastolic blood pressure than infants who were awake (P less than .001). Sex, body length, and feedings did not appear to influence infant's blood pressure nor did the anesthesia given to the mothers. Maternal diastolic pressure correlated with infant's diastolic pressure (regression coefficient, .128) (P less than .01), whereas for systolic pressure the regression coefficient between maternal and infant pressure was .085 (P=NS). The aggregation between the diastolic blood pressures of infants and mothers was not influenced by birthweight, age of the mother, or medication administered to the mother. The pulse rates of black infants were significantly higher than those of white infants (P less than .002). There was no correlation between the pulse rates and blood pressures in infants.

Analysis of Variance↗
PubMed1975

Bile salt metabolism in the human premature infant. Preliminary observations of pool size and synthesis rate following prenatal administration of dexamethasone and phenobarbital.

Bile salt synthesis and bile salt pool size were determined by isotope dilution in two groups of healthy premature infants, utilizing nonradioactive deuterium-labeled bile salts. All 9 infants were between 32 and 36 weeks of gestation; however, in one group (4 infants), the mothers had received either dexamethasone or phenobarbital prior to delivery. The total bile salt pool averaged 20 mg for the infants of untreated mothers and 79 mg for the infants of treated mothers; similarly, the bile salt synthesis of 8 mg per day in the untreated group was increased to 27 mg per day for the treated group. Expressed per sq m of body surface, the cholic acid pool for the treated group was 321 mg per sq m, and the cholic acid synthesis rate equaled 98 mg per sq m per day; values equal to those for full term infants and nearly 4 times those for the untreated prematures. The intraduodenal bile salt concentrations obtained during meals were also low in the untreated group, equaling 1.2 mM as compared to 5.3 mM for the treated group. The reductions of bile salt pool size, synthesis, and intestinal concentration establish that the functional maturity of the liver, and possibly the gastrointestinal tract, is reduced in premature infants. The results further suggest that this maturity may be dramatically influenced by medications administered to the mother prior to delivery.

Bile Acids and Salts↗