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Biomedical subjects

K Sankaran

Publications and source records attributed to K Sankaran.

At least 19 recordsLinked to original sources
PubMed1992

Pulmonary hemorrhage in premature infants after treatment with synthetic surfactant: an autopsy evaluation. The American Exosurf Neonatal Study Group I, and the Canadian Exosurf Neonatal Study Group.

In an across study analysis of five multicenter, placebo-controlled trials of the synthetic surfactant, Exosurf Neonatal in infants weighing at least 700 gm, the incidence of clinical pulmonary hemorrhage was 1.9% in treated infants and 1.0% in control infants. To investigate whether a similar increase was also present histologically at postmortem examination, a blinded retrospective review of all autopsy reports from infants dying during these five trials was conducted. Pulmonary hemorrhage was present in 55% of 159 infants undergoing autopsy; the incidence was not different in infants treated with surfactant or air placebo. Birth weight was inversely related to the incidence of pulmonary hemorrhage in both groups. Pulmonary pathologic findings significantly associated with pulmonary hemorrhage included pulmonary interstitial emphysema and necrotizing laryngotracheitis in both groups. In the surfactant group, patent ductus arteriosus, intraventricular hemorrhage, and pneumothorax were significantly more frequent among those who developed pulmonary hemorrhage. In contrast to clinical diagnosis, pathologic diagnosis of pulmonary hemorrhage at autopsy was not more common in infants treated with Exosurf Neonatal.

Autopsy↗
PubMed1992

Sedative/hypnotic effects of chloral hydrate in the neonate: trichloroethanol or parent drug?

Although the metabolism and pharmacokinetics of chloral hydrate (CH) have been reported, there have been no attempts to correlate CH or its metabolite, trichloroethanol (TCE) with the sedative or hypnotic effects. In order to determine whether plasma concentrations of CH or TCE reflect the sedative/hypnotic effects, a sedation/agitation scale was developed. Based on the results of the present study, the sedative/hypnotic effects of TCE cannot be ruled out completely. However, in the neonate, the parent drug CH seems to have a more important role than has been previously suggested from human research.

Chloral Hydrate↗
PubMed1992

Pulmonary eosinophilia in pulmonary tuberculosis.

Three radiologically and bacteriologically confirmed pulmonary tuberculosis patients had eosinophilic pneumonia, as demonstrated by BAL. In two patients, pulmonary eosinophilia was present only at the site of the lesion and the third had eosinophilia in both peripheral blood and lung. There was complete elimination of the eosinophilic inflammatory process in two patients who had successfully completed antituberculosis treatment.

Adult↗
PubMed1991

Effect of diethylcarbamazine on the alveolitis of tropical eosinophilia.

Bronchoalveolar lavage studies in 33 patients with acute untreated tropical eosinophilia have demonstrated intense eosinophilic alveolitis. Following treatment with a standard 3-week course of diethylcarbamazine, there was a significant fall in lung eosinophils (p less than 0.001). However, a mild alveolitis characterised by hypercellular lavage fluid due to a significant increase in absolute alveolar macrophages (p less than 0.001) and due to an increase in both the absolute number (p less than 0.01) and percentage of eosinophils (p = 0.02) was persisting at 1 month despite treatment. Long-term follow-up is essential to know the fate of alveolitis.

Acute Disease↗
PubMed1979

Immediate and late ventillatory response to high and low O2 in preterm infants and adult subjects.

The differences in the immediate (30 sec or 1 min) and late (5 min) ventilatory response to high and low O2 have not been quantitated in preterm infants and adult subjects using the same methods. It was thought that these differences might explain the paradoxical ventilatory response to CO2 at various O2 concentrations in preterm infants (12). Thus, 9 preterm infants and 10 adult subjects were given 21% O2 to breathe and then 100 or 15% O2 for 5 min each. Adults also breathed 15% O2 before 100% O2 or 12% O2 in order to make their resting arterial PO2 more comparable to those of infants breathing 21% O2. The ventilatory response to 100% O2 was the same in preterm infants and adult subjects, but the late response to 15% O2 remained paradoxical, ventilation decreasing at 5 min by 18% in infants and increasing by 19% in adults. The authors conclude: 1) the traditional concept of the ventilatory response to 100% O2 being different in infants and adult subjects is false; 2) the notion that the response to low O2 is paradoxical in infants is correct; and 3) the data do not explain why the response to CO2 under various background concentrations of O2 in infants is the reverse of that in adult subjects, but the depressed ventilatory response to hypoxia in infants may justify, at least in part, their flatter response to CO2 during low O2 breathing.

Adult↗
PubMed1979

Effect of sleep state on chest distortion and on the ventilatory response to CO2 in neonates.

In 10 preterm and 10 term infants, the effect of sleep state on chest distortion and on the ventilatory response to CO2 was assessed. It was found that chest distortion and ventilatory response to CO2 were independent of sleep state. Chest distortion, however, was more frequent in preterm than in term infants. The authors suggest that the increased prevalence of chest distortion in preterm infants is related to their highly compliant chest wall rather than to differences in sleep state.

Carbon Dioxide↗
PubMed1979

Quantitative noninvasive method to measure cerebral blood flow in newborn infants.

We measured cerebral blood flow (CBF) in 32 healthy neonates by venous occlusion plethysmography. Mean CBF was 63 ml/min/100 gm which compared favorably with invasive methods used in older children and adult subjects. We suggest that this is a useful method to quantify CBF in neonates. It may be valuable in assessing sequential changes occurring during asphyxia, intracranial hemorrhage, or during administration of various gas mixtures and drugs such as theophylline.

Blood Flow Velocity↗
PubMed1978

Physiologic changes induced by theophylline in the treatment of apnea in preterm infants.

Ten preterm infants (birth weight 0.970 to 2.495 kg) with apnea due to periodic breathing (apneic interval = 5 to 10 seconds) or with "serious apnea" (greater than or equal to 20 seconds) were studied before and after the administration of theophylline. We determined the incidence of apnea, respiratory minute volume, alveolar gases, arterial gases and pH, "specific" compliance, functional residual capacity, and work of breathing. Theophylline decreased the incidence of apnea (P less than .05), increased respiratory minute volume (P less than 0.001), decreased (PACO2 (and PaCO2 P less than 0.001), increased the slope of the CO2 response curve (P less than 0.02) with a significant shift to the left (P less than 0.02). These findings suggest that the decreased incidence of apnea after theophylline is associated with an increase in alveolar ventilation and increased sensitivity to CO2 with a pronounced shift of the CO2 response curve to the left. These data are consistent with the idea that apnea is a reflection of a depressed respiratory system.

Apnea↗
PubMed1978

Heat-stable low molecular weight form of phosphodiesterases from bovine pineal gland.

The 105,000 X g supernatant fraction of bovine pineal gland contains a phosphodiesterase activity that hydrolyzes both cyclic AMP and cyclic GMP. The rate of hydrolysis is 4-5 times greater with cyclic GMP as substrate than with cyclic AMP. Chromatography of supernatant fraction on Sephadex G-150 resolves phosphodiesterase activity into two fractions designated PDE I and PDE II. These are distinguishable on the basis of their molecular size, substrate specificity, and kinetic parameters. PDE I hydrolyzes cyclic GMP at a faster rate than cyclic AMP and has a molecular weight of 163,000. PDE II appears to be a smaller protein with a molecular weight of 24,400 and is specific for cyclic AMP. PDE I has apparent Km values of 83 and 53 micron for cyclic AMP and cyclic GMP, respectively, whereas PDE II exhibits an apparent Km value of 330 micron for cyclic AMP. With subsaturating concentrations of cyclic AMP as substrate, the phosphodiesterase activity of PDE I is inhibited by the addition of cyclic GMP. However, PDE II activity remains unaffected by cyclic GMP even at concentrations up to 125 micron. PDE II appears to be thermostable, losing only 20% of its activity on heating at 80 degrees for 2 min. Similar treatment completely abolishes the enzyme activity of PDE I.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1977

Maternal and neonatal effects of methoxyflurane, nitrous oxide and lumbar epidural anaesthesia for Caesarean section.

General anaesthetic techniques continue to be used for Caesarean section despite the possible increased incidence of foetal acidosis and neonatal depression. Two techniques of general anaesthesia (methoxyflurane-oxygen and nitrous oxide-oxygen) and lumbar epidural anaesthesia were compared in 37 patients under-going elective Caesarean section. Apgar scores at birth were similar in all three groups. Neurophysiological testing of the neonates at six hours and twenty-four hours of age revealed a superiority for the methoxyflurane-oxygen and lumbar epidural techniques, although the babies in the epidural group tended to be hypotonic. Cord blood gas analysis showed the babies in the methoxyflurane group to have a higher PaO2 with less metabolic acidosis than the babies from the other two groups. The maternal effects of the three anaesthetic techniques were similar, with only a small rise in serum fluroide levels noted in the methoxyflurane group.

Anesthesia, Epidural↗
PubMed1977

Lenticonus in Alport's syndrome. A family study.

A South Indian family with three well documented cases of Alport's syndrome with anterior lenticonus are reported. Clinical features of the syndrome including ocular and laboratory findings have been presented and discussed. Macular pigmentation, 5 cases, subcapsular opacity and nephrotic syndrome, one case each, observed in the present series are of great interest and are quite rare in patients with Alport's syndrome. Critical analysis of the family pedigree revealed autosomal dominance with incomplete penetrance as the possible mode of genetic transmission of the disease.

Adolescent↗