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Biomedical subjects

F Cockburn

Publications and source records attributed to F Cockburn.

99 records · Page 6Linked to original sources
PubMed1967

Pulmonary vasoconstriction in asphyxia during cross-circulation between twin foetal lambs.

1. The effect of asphyxia on pulmonary vascular resistance was measured in anaesthetized foetal lambs whose left lung was supplied with arterial blood from a twin, both still being attached to their placentas by intact umbilical cords.2. In foetal lambs of 91-92 days gestation asphyxia of the recipient caused no pulmonary vasoconstriction so long as its left pulmonary artery was supplied with normal blood from a twin donor. Asphyxia of the donor caused pulmonary vasoconstriction in the unasphyxiated recipient; this was therefore wholly due to a local effect of the blood passing through the lung.3. In foetal lambs of 98-142 days gestation asphyxia of the recipient caused a small degree of pulmonary vasoconstriction, even though the left pulmonary artery was supplied with normal blood from the twin donor. This vasoconstriction was abolished by administration of hexamethonium or by cutting the sympathetic nerves to the left lung.4. In mature foetal lambs pulmonary arterial inflow and venous outflow were measured simultaneously. Broncho-pulmonary blood flow was less than 5% of total pulmonary flow. Pulmonary O(2) consumption was 0.75 +/- 0.11 ml./100 g.min, or about 5% of total foetal O(2) consumption.

Animals↗
PubMedDate not supplied

Linkage analysis in a large family with nonspecific X-linked mental retardation.

We report on a large 5-generation family with "nonspecific" X-linked mental retardation. Nine living affected males have an IQ between 50 and 70 but have normal stature, facial appearance, and testicular volumes and no other abnormalities. Two obligate carrier females had borderline intellectual abilities and visual-psychomotor difficulties similar to those seen in affected males. Results of chromosome studies, including fragile X, were normal in males and females. Linkage analysis was undertaken, with 19 X-specific chromosomal restriction fragment length polymorphisms (RFLPs), giving a maximal LOD score of 1.60 at a 0.10 recombination fraction for F9, suggesting a localization to distal Xq for the mutant gene in this family.

DNA Probes↗
PubMedDate not supplied

Linkage analysis in the fragile X syndrome using multiple distal Xq polymorphic DNA markers.

Linkage data using the polymorphic loci F9, DXS105, DXS98, DXS52, DXS15, and F8 and the DNA probe 1A1 are presented from 14 families segregating for fragile X [fra(X)] syndrome. Recombination fractions corresponding to the maximum LOD scores obtained by two-point linkage analysis suggest that DXS98 (Zmax = 3.23, theta = 0.0) and DXS105 (Zmax = 2.09, theta = 0.0) are the closest markers proximal to FRAXA and that DXS52 is the closest distal marker (Zmax = 3.55, theta = 0.16). FRAXA is located within a 25 cM interval between F9 and DXS52, coincident with DXS98, on multipoint linkage analysis. Phase-known three way crossover information places F8 outside the cluster (DXS52, DXS15, 1A1). Confidence limits for the markers DXS98 and DXS52 are relatively wide (0.0-0.15 and 0.06-0.31, respectively), but when used in combination with cytogenetic examination offer improved carrier detection in comparison with cytogenetic analysis alone.

Blotting, Southern↗
PubMedDate not supplied

Pharmacokinetic study of sulbactam and ampicillin administered concomitantly by intraarterial or intravenous infusion in the newborn.

The combination of sulbactam and ampicillin was administered to 16 newborn infants, 15 preterm and one term, who required umbilical arterial or venous catheterization and prophylactic antibiotics. The aims were to determine an appropriate dosage regimen and to study the pharmacokinetics. Satisfactory plasma concentrations were achieved with administration of a bolus injection of 50 mg of each drug/kg every 12 hr (mean concentrations: sulbactam, 110 mg/liter; ampicillin, 87 mg/liter 3 hr after dosing; and sulbactam, 105 and 135 mg/liter; ampicillin, 320 and 310 mg/liter 30 min after dosing in two infants. Mean elimination half-lives were longer than those in adults (sulbactam, 7.9 hr; ampicillin, 9.4 hr), and urinary excretion over 12 hr varied considerably (range: sulbactam, 7%-91%; ampicillin, 5%-132%), rates reflecting the immature renal function in the newborn and the relative oliguria characteristic of preterm infants with idiopathic respiratory distress syndrome. There was little evidence of accumulation of either drug, and both were well tolerated. This combination and dosage should be suitable for a trial of therapy for infection in the newborn.

Ampicillin↗