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R Dhanireddy

Publications and source records attributed to R Dhanireddy.

28 records · Page 2Linked to original sources
PubMed1989

Pulmonary management during extracorporeal membrane oxygenation.

Traditional lung management during extracorporeal membrane oxygenation (ECMO) calls for low inspiratory and expiratory pressures with low ventilator rate to achieve lung rest. However, rapid weaning of pressures to severely injured lungs commonly leads to marked increase in pulmonary opacification as seen on chest x-ray and loss of volume. We postulated that a sufficiently high level of PEEP could prevent this deterioration. Forty-six newborns, who required ECMO therapy for refractory respiratory failure, were maintained on 8 to 14 cm H2O PEEP. The peak pressure was 20 to 24 cm H2O, rate 10 to 15 breath/min, and FIO2 0.21. Forty-one (89%) of 46 patients survived to discharge. The duration of ECMO was significantly decreased compared to the national average (82.4 +/- 43 vs. 117.5 +/- 59 h). The lungs of most patients remained adequately expanded and free of severe pulmonary opacification. Eleven of 40 patients did show significant worsening of chest x-ray compared to baseline, but only one of 18 who were on PEEP of greater than or equal to 12 cm H2O showed such deterioration. No unexpected complications were encountered. These data suggest that the use of high PEEP during ECMO safely prevents deterioration of lung function and promotes more rapid lung recovery. PEEP levels of 12 to 14 cm H2O appear to be most effective.

Extracorporeal Membrane Oxygenation↗
PubMed1988

Detection of a rabbit uteroglobin-like protein in human neonatal tracheobronchial washings.

Uteroglobin is a steroid hormone dependent, low molecular weight, secretory protein with many immunomodulatory properties. Immunomodulation by this protein may, at least in part, be related to its inhibitory effects on phospholipase A2 activity. Although uteroglobin is conclusively found in the rabbit, its presence in the human is controversial. Here, we present biochemical and immunological evidence for the detection of a uteroglobin-like protein in the wet epithelial living of the respiratory tract of human neonates. Because inhibition of phospholipase A2 may modulate tissue eicosanoid levels and since many eicosanoids (i.e. prostaglandins and leukotrienes etc.) are well known regulators of smooth muscle contractility, cellular migration and inflammatory processes, the discovery of this protein in the human respiratory tract may have important physiological implications.

Animals↗
PubMed1985

Lipid clearing in premature infants during continuous heparin infusion: role of circulating lipases.

The nature of the lipases released into the circulation during low level continuous infusion of heparin (1 unit/ml total parenteral nutrition) and after bolus heparin injection (10 units/kg) was investigated in a group of 11 low birth weight infants (gestational age 27-34 wk, and postnatal age of 7-26 days) receiving total parenteral nutrition with Intralipid (0.5 g/kg). Hepatic lipase and extra-hepatic lipoprotein lipase were differentiated with the aid of an antibody specific for human hepatic lipase. The data show that continuous low level heparin infusion leads to a constant baseline postheparin lipolytic activity of 0.77 +/- 0.18 mumol free fatty acids released per milliliter serum per hour. Bolus heparin injection leads to peak lipolytic activity levels of 3.77 +/- 0.46 mumol free fatty acids per milliliter serum per hour, 10 min after injection. About two-thirds of the total postheparin lipolytic activity was of the hepatic type during low level continuous infusion or after bolus injection of heparin.

Birth Weight↗
PubMed1984

Prolactin binding in the developing rat fetal liver.

The binding of prolactin by fetal rat liver cell membrane fractions from 17 to 21 days gestation was studied. Particulate liver membranes were prepared in Dulbecco's Phosphate Buffered Saline (PBS) by ultracentrifugation and incubated at 22 degrees C for 16 hours with [125I] iodo-human growth hormone (hGH). Non-specific binding was assessed by parallel incubations in the presence of a 2000-fold excess ovine prolactin. Specific prolactin binding sites were detected only at 21 days gestation (2932 +/- 401 cpm/mg protein) in freshly prepared membranes. On freezing at -20 degrees C for 24 to 48 hours, the membranes of 20 days gestation animals were able to specifically bind prolactin (1295 +/- 239 cpm/mg protein). Freezing led to a 45 +/- 7% increase (4270 +/- 701 cpm/mg protein) in prolactin binding at 21 days gestation. No hormonal binding was detected from 17 through 19 days gestation in either fresh or freeze-thawed membranes. Scatchard analysis revealed a high affinity binding site with a Ka of approximately 1.4 X 10(8)M-1 in both fresh and freeze-thawed membrane preparations. The data show that 1) prolactin receptors appear in liver only during late fetal life and that 2) freezing of membranes may unmask binding sites that are initially unavailable to specifically bind prolactin.

Animals↗
PubMed1983

Respiratory distress syndrome in the newborn: relationship to serum prolactin, thyroxine, and sex.

Prolactin and thyroxine levels were measured by radioimmunoassay in cord blood of 61 premature infants of 26-36 weeks gestation. 30 of the infants subsequently developed respiratory distress syndrome (RDS). The infants who developed RDS had a mean cord prolactin level of 174.5 +/- 24.5 ng/ml and a mean cord thyroxine level of 5.9 +/- 0.4 micrograms/dl. In the 31 healthy infants, the mean cord prolactin and thyroxine levels were significantly higher (226.3 +/- 25.8 ng/ml and 7.1 +/- 0.4 micrograms/dl, respectively). The correlation coefficient between prolactin and thyroxine was r = 0.56 in infants with RDS (p less than 0.0008). Both prolactin and thyroxine correlated with gestational age in the RDS group (r = 0.71 and 0.47, respectively). Discriminant analysis shows that the correlation between prolactin and thyroxine is independent of gestational age (r2 = 0.32, p less than 0.05). There was no correlation between the levels of prolactin and thyroxine in infants without RDS. In the healthy group, the cord prolactin levels were significantly higher (p less than 0.01) in female (335.8 +/- 47.7 ng/ml) than in male infants (209 +/- 17.2 ng/ml). Premature infants who develop RDS have significantly lower thyroxine and prolactin levels in cord blood than infants who remain healthy.

Female↗
PubMed1981

Postheparin lipolytic activity and Intralipid clearance in very low-birth-weight infants.

The effect of heparin (10 U/kg) on serum lipolytic activity, triglyceride and FFA levels, during four hours infusion of 0.5 gm/kg Intralipid was measured in 18 AGA infants, 25 to 32 weeks' gestational age. PHLA, TG, and FFA were measured at 0, 10, 30, 120, and 240 minutes of infusion of Intralipid, before and following a bolus of 10 U/kg heparin iv. Lipolytic activity, measured by hydrolysis of activated tri-3H-oleate and expressed in mumol FFA released per milliliter serum per hour, was not detected in serum before heparin administration. Ten minutes after heparin administration peak PHLA was significantly higher in infants of 27 to 32 weeks' gestation than in infants of 25 to 26 weeks' gestation. There was no significant difference in peak PHLA between infants of 27 to 28 and 29 to 32 weeks' gestation. PHLA returned to baseline (zero) two hours after heparin administration in all infants. Infants of 25 to 26 weeks' gestational age had significantly higher concentrations of serum triglycerides before and during Intralipid infusion than in infants of 27 to 32 weeks' gestational age. Although there was a transient rise in FFA 10 and 30 minutes after heparin administration, the levels of FFA and triglycerides were not different at the end of infusion with or without heparin in either group, suggesting that a single bolus of heparin has only a transient effect on Intralipid clearance.

Fatty Acids, Nonesterified↗
PubMedDate not supplied

Dose-dependent evaluation of the effects of nebulized furosemide on pulmonary function in ventilated preterm infants.

OBJECTIVE: We have previously shown that a single dose of nebulized furosemide improves tidal volume and pulmonary compliance for up to a 2-hour study period. This study is undertaken in order to find out (a) whether increasing the dose of nebulized furosemide from 1 to 2 mg/kg of body weight will further improve the pulmonary mechanics in premature infants with evolving chronic lung disease and (b) whether the effects of a single dose of nebulized furosemide last beyond 2 hours. STUDY DESIGN: The effect of nebulized furosemide on pulmonary mechanics was studied at a mean postnatal age of 24 days (range 14 to 50 days) in 13 premature infants, 24 to 28 weeks' gestational age, who had been dependent on mechanical ventilation since birth. Furosemide was administered by nebulization at doses of 1 and 2 mg/kg of body weight, in random order, on two separate days 24 hours apart. Pulmonary function studies were performed before and 2, 4, and 6 hours after the nebulization. Urine was collected for 6 hours immediately before and for 6 hours after the nebulization. RESULTS: Furosemide by nebulization at 1 and 2 mg/kg of body weight resulted in significant improvement in tidal volume and compliance. There was no difference in the magnitude of response between the two doses. Neither 1 nor 2 mg/kg of body weight of nebulized furosemide had any effect on airway resistance. The improvement was maximum for up to 4 hours and lasted for up to 6 hours after the nebulization and was not associated with diuresis or increased excretion of urinary electrolytes. CONCLUSION: A single dose of nebulized furosemide improves pulmonary function for up to 6 hours after its administration. Increasing the dose from 1 to 2 mg/kg of body weight results in no further improvement in the pulmonary function. The pulmonary effects of nebulized furosemide are independent of its diuretic action.

Aerosols↗