All low birthweight babies ventilated for the respiratory distress syndrome during a period of fourteen months were randomised to receive endotracheal suction 12-hourly or 6-hourly. There were no significant differences in respiratory outcome between the groups. These observations suggest that it is safe to aspirate endotracheal tubes infrequently during the first few days in uncomplicated respiratory distress syndrome.

Humans↗

PubMed1991

Sudden infant death.

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Attitude to Health↗

PubMed1989

Analogues of cisplatin derived from diaminodideoxytetritols. Synthesis and activity against the ADJ/PC6 plasmacytoma in mice.

Four new analogues of the anticancer drug cisplatin have been prepared that contain a diaminodideoxytetritol derivative as the amine ligand moiety, and their activities have been measured against the ADJ/PC6 plasmacytoma in mice. Two of these compounds, the enantiomers of cis-dichloro(1,4-diamino-1,4-dideoxy-2,3-O-isopropylidenethreitol) -platinum(II) , show a higher TI value than cisplatin when administered by intraperitoneal injection and, importantly, show significant antitumour activity when administered orally.

Administration, Oral↗

PubMed1988

A cell-specific activator in the Xenopus A2 vitellogenin gene: promoter elements functioning with rat liver nuclear extracts.

Transfection experiments using Xenopus vitellogenin A2 gene constructs allowed us to identify an activator which increases the activity of the thymidine kinase promoter. The activator is located between -121 and -87 of the A2 vitellogenin gene and is separated by a stretch of curved DNA from the estrogen-responsive DNA element at -331. The activator functions in a cell-specific manner, as it is active in human breast cancer cells (MCF-7) as well as hepatoma cells but not in fibroblasts or HeLa cells. The activator is composed of at least three elements: elements 1 and 2 which form a partial palindrome, function independently, but act synergistically when combined. Element 3 is not active on its own, but supports elements 1 and 2. A TATA box region derived from the Xenopus albumin gene is sufficient for the function of the activator. In vitro transcription experiments using rat liver nuclear extracts demonstrate that the activator interacts with transcription factors. These factors are distinct from those recognizing HP1, a regulatory element common to several genes specifically expressed in hepatocytes.

Animals↗

PubMed1988

Tracheal aspirates from neonates during endotracheal intubation: detection of surfactant by polarized light microscopy.

A technique for detecting the presence of pulmonary surfactant in the tracheal aspirates obtained from preterm babies is described. The specimens were examined by means of polarized light microscopy. Surfactant could be simply and rapidly identified by its appearance as birefringent particles in volumes of aspirate as little as 1 microliter. Tracheal aspirate specimens from 108 babies, obtained on the first day of life, were examined without knowledge of the patient's clinical details. When the samples from each baby were subdivided into three groups on the basis of the amount of surfactant particles seen, this subgrouping corresponded well with the babies' ventilatory requirements at the time of sample collection. This method of detecting surfactant material may prove valuable in determining the degree of surfactant deficiency in individual preterm babies with respiratory illness.

Humans↗

PubMed1988

Lung surfactant and sudden infant death syndrome.

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Humans↗

PubMed1988

Effect of indomethacin and of prostaglandins on extrarenal erythropoietin production in rats.

Indomethacin elevates the plasma erythropoietin titer of hypoxic anephric rats and probably does so by increasing extrarenal erythropoietin production. Because indomethacin is a potent cyclooxygenase inhibitor, we postulated that it alters extrarenal erythropoietin production via its effects on tissue prostaglandin levels. Studies were, therefore, performed to determine the effects of indomethacin on hepatic prostaglandin E2 (PGE2) and prostaglandin F2 alpha (PGF2 alpha) titers. Indomethacin significantly decreased the PGF2 alpha level but its effects on the PGE2 level were, in most experiments, insignificant. We next studied the effects of infusing PGF2 alpha and PGE2 on the plasma erythropoietin levels of hypoxic rats. PGF2 alpha significantly reduced the plasma erythropoietin titer of anephric rats and neutralized the effect of indomethacin when both substances were administered. PGE2 infusion, on the other hand, did not significantly affect the plasma erythropoietin level of anephric rats. The data support the conclusion that PGF2 alpha is a potent inhibitor of extrarenal erythropoietin production, and that indomethacin enhances the rate of extrarenal erythropoietin production by reducing the PGF2 alpha titer in the liver.

Animals↗

PubMed1987

Comparison of different rates of artificial ventilation in preterm neonates with respiratory distress syndrome.

The effectiveness of three different ventilator rates of artificial ventilation (30, 60 and 120/min) was studied in 32 preterm infants, all of whom were suffering from the Respiratory Distress Syndrome (16 were paralysed). Ventilator pressures, I:E ratio and MAP were kept constant at each rate. Increase in rate from 30 to 60 and to 120/min was well tolerated and not associated with episodes of hypotension. The only significant improvement in oxygenation was amongst the non-paralysed infants and at a rate of 120/min (p less than 0.01) this was associated with synchronous respiration. Two different ventilators were used in the study and a significant change in PaCO2 (reduction) occurred only in non-paralysed infants ventilated at a rate of 120/min by Sechrist ventilators (p less than 0.05). This difference may be a direct reflection of differences in ventilator performance at fast rates.

Airway Resistance↗

PubMed1987