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Biomedical subjects

D Vidyasagar

Publications and source records attributed to D Vidyasagar.

At least 73 records · Page 4Linked to original sources
PubMed1988

Morbidity and mortality factors in twins. An epidemiologic approach.

Some epidemiologic characteristics of twin pregnancies and twin infants have been reviewed. We found that twins are prone to be born prematurely and have lower birth weights than their singleton counterparts after 30 to 34 weeks of gestation. Twins are also more prone to birth asphyxia, hyaline membrane disease, respiratory disorders, and seizures. Congenital anomalies and nonrespiratory morbidity were not found to be increased in twins. Twins have a six times higher perinatal mortality rate than do singletons. This is accounted for by prematurity in the main. A part of the excess mortality in twins is accounted for by a higher mortality in larger, near-term twins. Efforts should be directed toward decreasing the incidence of prematurity in twins and understanding and managing the problems of near-term twins better.

Asphyxia Neonatorum↗
PubMed1988

Early and late surfactant treatments in baboon model of hyaline membrane disease.

Because the issue of optimal time for artificial surfactant therapy for hyaline membrane disease has not been established, the effects of treatment with a reconstituted bovine surfactant (surfactant TA) were compared at two time periods in a hyaline membrane disease model in a premature baboon. The baboons were delivered by cesarean section at 75% of gestation (139.5 +/- 1.5 days, mean +/- SD). One group was treated with surfactant TA within ten minutes after birth (ultraearly), another group was treated at two hours of age (late) and a third (comparison group) did not receive the surfactant. Both treatment groups had significantly higher compliance and ratio of arterial to alveolar Po2 ratio and lower mean airway pressure and oxygen requirement (Fio2) than the comparison group. At autopsy, the largest residual volume and hysteresis in pulmonary pressure-volume curves were noted in the ultraearly group, intermediate values were found in the late group, and least values were found in the comparison group. These data indicate that early surfactant therapy for hyaline membrane disease results in greater improvement in lung mechanics than delaying treatment, even for two hours. Delivery room treatment with surfactant of infants at risk for hyaline membrane disease is perhaps better than therapy for established hyaline membrane disease.

Animals↗
PubMed1987

Double-blind controlled trial of single-dose treatment with bovine surfactant in severe hyaline membrane disease.

In a double-blind clinical trial the effects of a single dose of reconstituted bovine surfactant ('Surfactant TA') were assessed in 30 premature infants (birthweight 751-1750 g) with severe hyaline membrane disease. 17 infants had a sonicated saline suspension of 100 mg/kg surfactant phospholipid instilled into the trachea at 5.0 (SD 0.7) hours of age and 13 infants received saline by the same route at 4.3 (1.1) hours of age. In the surfactant-treated group there was early improvement in oxygenation and ventilation. Haemodynamically significant patent ductus arteriosus occurred more often in the surfactant group; pneumothorax and pulmonary interstitial emphysema occurred less often. The combined incidence of death and severe bronchopulmonary dysplasia was significantly lower in the surfactant group (3/17) than in the placebo group (9/13).

Animals↗
PubMed1987

Lipogenesis in the brown adipose tissue of the fetal baboon.

The ultrastructural and lipogenic capacity of the white and brown adipose tissue (WAT and BAT) of 10 baboon fetuses (gestational age, 138-183 days) were studied. The axillary, interscapular and pericardiac sites had at least 50% brown fat cells while the retroorbital site contained white adipocytes only. Both WAT and BAT incorporated 3H2O and 14C-glycerol into lipids at similar high rates. The activities of enzyme acetyl CoA carboxylase and glycerokinase were higher than those reported in human BAT and comparable to these reported in rodent BAT under unstimulated conditions. It is concluded that in the fetal baboon adipose tissue is capable of considerable de novo lipogenesis and that, despite the differences in microscopic appearance, WAT and BAT have similar lipogenic potentials with respect to the parameters measured.

Acetyl-CoA Carboxylase↗
PubMed1987

Effect of hepatic cytosol on postnatal drug metabolism.

Postnatal maturation for indomethacin O-demethylation in freshly isolated hepatocytes and 10,000 g liver homogenates of rabbit was found to be significantly different from that observed in rabbit hepatic microsomes. Addition of hepatic cytosol (100,000 g supernatant) from day 10 postnatal rabbits significantly inhibited indomethacin O-demethylation by hepatic microsomes from adult rabbits. Kinetic studies demonstrated that the inhibition was competitive and consistent with the concentration of cytosol. The pattern of postnatal maturation for hepatic microsomal drug metabolism may in part be related to changes in the concentration of endogenous cytosolic inhibitors.

Animals↗
PubMed1987

Surfactant replacement therapy: clinical and experimental studies.

Surfactant replacement therapy has been investigated extensively both in animal models and clinical studies. Although not yet available for routine clinical treatment, surfactant replacement in HMD holds great promise. This article reviews the current literature in this area.

Animals↗
PubMed1987

Pulmonary surfactant replacement in respiratory distress syndrome.

Exogenous surfactant therapy in infants with HMD leads to dramatic improvement in oxygenation and disease course. Both prophylactic and rescue treatments have shown a significant reduction in morbidity and mortality from the disease. There are several questions yet to be answered regarding the most effective surfactant, the appropriate time of treatment, and the appropriate dose, as well as the number of treatments required. Based on the available data, surfactant TA has shown promising and consistent results. Another important question to be answered is the role of surfactant in milder cases of HMD and its impact on the cost of hospitalization. Hopefully, future studies will be able to provide answers to these questions.

Humans↗
PubMed1987

Perinatal morbidity and mortality in a regional perinatal network.

A study of pregnancy outcome was performed using a 1982-1985 regional network database of 60,456 infants. The perinatal mortality rate was 15.6 deaths per 1,000 births (total, 942), while the antepartum, intrapartum and neonatal mortality rates were 5.3, 1.6 and 8.7, respectively. Seven hundred forty-three multiple gestation pregnancies (1.2%) and 1,632 major congenital anomalies (2.7%) were identified. The corrected perinatal mortality rate was 13.8 deaths per 1,000 births. This study revealed that prematurity, postdatism, congenital anomalies, low Apgar scores and neonatal complications, including respiratory distress syndrome, pneumothorax, persistent fetal circulation, intracerebral hemorrhage and seizure activity, were major factors contributing to mortality. This analysis suggests that a further reduction in mortality should follow a reduction in preterm deliveries and their sequelae and the early identification and management of maternal and fetal antenatal complications.

Female↗
PubMed1986

Effect of tolazoline on renal function in newborn puppies.

Tolazoline is used in pulmonary hypertension and hypoperfusion syndrome during the neonatal period. Some of the side effects of tolazoline are hypotension, bleeding disorders and renal dysfunction. The present study was designed to investigate the effect of hypoxia and tolazoline on renal function in newborn puppies. The data in normal animals administered tolazoline alone did not reveal any statistically significant changes in blood pressure or in renal function. In the hypoxia group changes in renal function were noticed in spite of normal blood pressure. When tolazoline was administered to the hypoxic animals, a marked decrease in blood pressure resulted. Indeed, changes in renal function were more profound in the hypoxic animals receiving tolazoline than in hypoxic animals not receiving tolazoline, even though some of the renal functional values did not reach statistical significance.

Animals↗
PubMed1986

Infantile apnea.

Infants who are found apneic, limp and cyanotic or pale and who require resuscitation must be hospitalized for cardiorespiratory monitoring and medical evaluation. If no cause is found, the diagnosis of idiopathic infantile apnea is made. The impedance pneumocardiogram is often helpful in diagnosis and management. Home monitoring limits asphyxia and may prevent death in infants thought to be at risk for recurrent apnea.

Apnea↗
PubMed1985

Transmission of neonatal listeriosis in a delivery room.

Two cases of neonatal listeriosis occurred in a hospital within a two-week period. Both infants were infected with the same organism, Listeria monocytogenes, type 1a, bacteriophage type 6 (lysotype 1652). Both infants were born in the same delivery room, 17 hours apart. The index patient became septic shortly after birth and died after 48 hours despite antibiotic therapy. The mother of the index patient was febrile and had chorioamnionitis. The second infant became ill with meningitis at 13 days of age. Neither infants nor mothers were attended by the same medical or nursing staff nor were they in the same labor or postpartum areas or nurseries. However, both infants were resuscitated in the same delivery room after birth by means of laryngoscope, suction catheter, and emergency resuscitation (Ambu) bag. Although it was hospital policy to clean and sterilize resuscitation equipment after use, the equipment had only been wiped with alcohol between patients in this instance, since sterile replacement equipment was not available during the early-morning hours when the index birth occurred. Therefore, we believe the contaminated resuscitation equipment was the source of infection in the second infant. This episode emphasizes the importance of appropriate disinfection of respiratory resuscitation equipment to prevent nosocomial infection due to L monocytogenes, an unusual but important pathogen in neonates.

Cross Infection↗
PubMed1985

Uptake of taurocholate by freshly isolated hepatocytes from fetal and newborn rabbits.

During early postnatal maturation a significant increase in the rate constant of translocation (Michaelis-Menten constant; Km) for taurocholate uptake occurs in isolated rabbit hepatocytes. This age-dependent change is related to a decrease in the efficiency of uptake for taurocholate and is probably associated with changes in the receptor or its microenvironment within the plasma membrane. Cholic acid conjugates (taurocholic and glycocholic acids) are the predominant bile acids found in the premature and neonatal human. It is therefore of interest that in the fetal and neonatal rabbit we have found a developmentally dependent alteration of taurocholic acid transport.

Animals↗
PubMed1985

Effect of peritoneal dialysis on serum concentrations of three drugs commonly used in pediatric patients.

The use of peritoneal dialysis in young infants bears the theoretical advantage that the relative size of their peritoneal surface area is twice that of adults. The movement of drugs across the peritoneum is affected by the physiochemical properties of the drug molecules and the pathophysiologic condition of the patient. It is observed that the peritoneal dialysis clearances of phenobarbital, amikacin and cefazolin in infants were 1.07-1.33, 0.54-0.86 and 0.40-1.02 ml/min, respectively. The dosage determination in the dialysis patients receiving these drugs is discussed.

Amikacin↗
PubMed1985

Transcutaneous oxygen and carbon dioxide monitoring in sick neonates using a combined sensor.

Using a combined O2-CO2 sensor, we evaluated the effect of cathode size and membrane thickness and incorporation of correction factor upon transcutaneous O2-CO2 readings. The present studies were carried out in three phases in newborns less than a week of age. The data from these studies indicate that a combined O2-CO2 sensor with a smaller cathode, Teflon membrane and with a built-in correction factor can accurately reflect arterial O2 and CO2 tension and can replace the present two heated sensors.

Carbon Dioxide↗
PubMed1985

Bovine surfactant (surfactant TA) therapy in immature baboons with hyaline membrane disease.

As a prelude to clinical trials with a bovine surfactant (surfactant TA), in human infants with hyaline membrane disease, pulmonary and hemodynamic changes following its instillation in premature baboons were investigated. Baboons, delivered by cesarean section at 141 +/- 3.5 days (mean +/- SD, 77% gestation), were provided with intensive care. At 2 hours of age in one group (n = 10), 100 mg/kg of surfactant TA (reconstituted bovine surfactant, Tokyo Tanabe Co., Tokyo) was instilled into the lungs. Sequential measurements and monitoring of pulmonary and hemodynamic variables were carried out in these ten baboons and in a control group of five baboons for 16 hours, at which time the experiments were electively terminated. At birth, the pulmonary compliance, findings of chest radiographs, ratio of arterial PO2 to alveolar PO2, and respirator variables needed to maintain normal blood gas and acid base status were identical in both groups and indicative of severe hyaline membrane disease. Following surfactant instillation, the treated group demonstrated a rapid increase in PO2 with significantly improved ratio of arterial PO2 to alveolar PO2 (from a mean +/- SD pretreatment value of 0.21 +/- 0.11 to 0.45 +/- 0.11 by 16 hours). Pulmonary compliance improved similarly (from pretreatment value of 0.18 +/- 0.06 mL/cm H2O/kg to 0.27 +/- 0.09 mL/cm H2O/kg). Significant reduction in respirator support variables could be achieved in all treated animals; however, in the control animals, the pulmonary status worsened as evidenced by increasing mean airway pressure and respirator variables to keep normal blood gas and acid base status, thus worsening compliance. At autopsy, pulmonary pressure-volume curves were significantly different with large hysteresis obtained in the surfactant-treated group. Although no deleterious effect on hemodynamics was noted in surfactant TA-treated animals, a large patent ductus arteriosus was demonstrated by aortography. Increased lung blood flow, probably due to a large patent ductus arteriosus flow, was demonstrated by radiolabeled microsphere technique. The physiologic significance and clinical relevance of these findings in premature baboons treated with surfactant TA are discussed.

Animals↗