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Biomedical subjects

J Doyle

Publications and source records attributed to J Doyle.

At least 145 records · Page 8Linked to original sources
PubMed1986

Levels of 6-ketoprostaglandin F1 alpha in neonatal cerebrospinal fluid.

6-Ketoprostaglandin F1 alpha determinations were made by radioimmunoassay on samples of cerebrospinal fluid from 41 neonates. Levels were below the smallest quantity detectable (50 pg/ml) in 29 and greater than 200 pg/ml in only 3 babies. These results suggest that 6-ketoprostaglandin F1 alpha is not a major prostaglandin in the cerebrospinal fluid of human infants.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Reduction of immunoreactive prostacyclin metabolite after paralysis in ventilated preterm infants.

Levels of the stable metabolite of prostacyclin, 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) were measured by radioimmunoassay during the first 48 hours of life in a group of 20 infants ventilated for the respiratory distress syndrome in whom a simultaneous record of respiratory activity was made. 6-Keto-PGF1 alpha was significantly lower when the infants were paralysed (P = 0.0004) than when they were breathing spontaneously. Elimination of the capacity for spontaneous respiration may reduce barotrauma and hence the stimulus for prostacyclin release from the lung.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Ethamsylate reduces immunoreactive prostacyclin metabolite in low birthweight infants with respiratory distress syndrome.

Measurement of 6 ketoprostaglandin F1 alpha was made by radioimmunoassay during the first 3 days of life in 33 infants with respiratory distress syndrome who were subjects in a double blind controlled trial of ethamsylate for the prevention of intraventricular haemorrhage. Levels of 6-ketoprostaglandin F1 alpha were significantly lower on the first and second days of life in babies receiving ethamsylate. There was a reduction in the incidence of intraventricular haemorrhage in the treated group. High levels of prostacyclin metabolite are found in babies who develop haemorrhage, and reduction of prostacyclin synthetase activity may be the mode of action of this drug in vivo.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Early administration of indomethacin to preterm infants.

Indomethacin (0.2 mg/kg) or saline was given intravenously during the first 24 hours to 50 preterm infants in a double blind controlled trial. Eight of the control group later required treatment with indomethacin for clinical signs of left to right shunt, but only one in the treatment group (p = 0.03). Treatment with indomethacin prolonged bleeding time, raised serum creatinine concentrations, and was associated with gastrointestinal haemorrhage in seven infants. Five of these had a serum indomethacin concentration greater than 1.0 microgram/ml. There was a significant reduction of the stable metabolite of prostacyclin, 6-ketoprostaglandin F1 alpha, commencing six hours after treatment and lasting for four days. There was no significant difference in the incidence of intraventricular haemorrhage, days of treatment with oxygen or ventilation, or mortality between the two groups.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Channel catfish virus: use of nucleic acids in studying viral relationships.

Restriction digestion patterns were used to determine differences in the DNA of various isolates of channel catfish virus (CCV). All viruses were different from each other and from the type strain of CCV. The differences in the digestion patterns were used to relate the viruses quantitatively as to sequence divergence between all pairs of viruses. A range of values from 104 nucleotide changes to 1,690 nucleotide changes/total DNA of CCV was found for the various pairs. A cladistic analysis produced a phylogenetic network relating the viruses by possible ancestory. This network indicated that some viruses were relatively more separated from other viruses that were clustered in the network. A phenetic analysis indicated that the viruses that were clustered in the network were also reasonably similar to one another.

Animals↗
PubMed1985

The preoperative angiogram as a predictor of peripheral vascular runoff.

The preoperative angiogram is widely used as a means of assessing peripheral vascular runoff before bypass grafting, but the correlation between preoperative angiographic findings and actual measurements of peripheral vascular resistance has not been adequately examined. To test this correlation, we first devised a simple technique for measuring peripheral resistance and validated it in five dogs. Increases in peripheral resistance were artificially produced by temporarily occluding either the deep or superficial femoral artery or by intravenous administration of phenylephrine hydrochloride, a vasoconstrictor. In each instance, significant increases in resistance could be measured. We then used a similar technique to measure resistance in 23 patients undergoing peripheral bypass surgery. In addition, preoperative angiograms for these 23 patients were independently scored by four readers as 0, 1, 2, or 3 based on the number of patent vessels seen below the knee. Variations in scoring from reader to reader suggested that the present criteria for grading angiograms on this basis are unclear. Moreover, the correlation between angiographic score and measured resistance was poor for three of the four scorers (-0.21 to -0.29, p greater than 0.05). The angiographic scores of one reader, however, correlated reasonably well with the peripheral resistance measured at surgery (-0.59, p = 0.01). These findings demonstrate that current criteria for grading the preoperative angiogram are not sufficiently standardized to reliably predict runoff from a preoperative angiogram. However, these findings also suggest that it may be possible to identify angiographic findings that correlate well with changes in measured resistance.

Angiography↗
PubMed1984

Anticholinergic challenge and neuroleptic withdrawal. Changes in dyskinesia and symptom measures.

Benztropine mesylate (intravenous [IV] and oral) challenge was compared with brief neuroleptic withdrawal on dyskinesia ratings and symptom measures. Thirty-six neuroleptic-treated patients underwent a placebo-controlled acute IV challenge with 2 mg benztropine and a placebo-controlled two-week trial of oral benztropine mesylate (2 mg three times a day), followed by a double-blind placebo-controlled neuroleptic withdrawal involving four weeks of dose tapering and six weeks of placebo treatment. Benztropine given IV had no significant effect. Orally administered benztropine, however, led to statistically significant increases in dyskinesia and dysphoric mood. The brief neuroleptic withdrawal significantly increased dyskinesia scores and dysphoria and resulted in early termination of therapy in 12 of 36 patients (33%) due to symptom exacerbation. There was a striking absence of correlation between dyskinesia change measures brought about by benztropine and changes following neuroleptic withdrawal. Therefore anticholinergic challenge does not appear to be a fruitful procedure for identifying patients with covert dyskinesia.

Administration, Oral↗
PubMed1980

Combined effects of alcohol and sleep deprivation in normal young adults.

The effect of combining sleep deprivation and moderate alcohol consumption in male college students differed from the effects of each treatment alone. Following either alcohol or sleep deprivation, there was mild performance impairment, decreased alertness and reduced amplitude and increased latency of cortical evoked potential (EP) components. Heart rate increased after alcohol and anxiety increased after sleep deprivation. When alcohol and sleep deprivation were combined, antagonistic effects were found for most measures (reaction time, heart rate, alertness, anxiety, latency of early EP components), but synergistic effects also occurred (performance accuracy, latency of late EP components). These effects were found in a double-blind experiment using 24 subjects. The experimental treatments were alcohol doses of 0, 0.45 and 0.90 ml/kg of 95% ethanol and 0 and 26 h of sleep deprivation.

Adult↗