Influence of pericardial fluid on cardiogenic gas mixing in the lung

Respirat. Environ. Exercise Physiol. 42(1): 5-12, 1977. -In eight open-chested dogs we measured the end-inspiratory N2 concentration within 12 airways, 2.5-8.3 mm in diameter during constant flow inflations with 0.5 liter of O2 before and after the introduction of saline into the pericardial sac. The critical flow rate necessary to achieve a given end-inspiratory FN2, as well as the maximal amplitude of cardiogenic N2 fluctuations, became smaller in the presence of pericardial fluid (PF). In the presence of only 25-50 ml of saline in the pericardium the effective diffusion coefficient, incorporating cardiogenic gas mixing, decreased by as much as 50-66%, respectively. Studies in two dogs with the chest intact showed that PF caused a qualitatively similar impairment of gas mixing during breath holding. Multiple-breath N2 washouts did not reflect the decreases in gas mixing produced by PF. We believe that PF decreases cardiogenic gas mixing mainly by protecting the lung from the rotational thrust of the heart during myocardial contraction.

A microfluorometric assay of leukocyte alpha-1,4-glucosidase

We describe an improved method for detecting deficiency of the acid hydrolase, alpha-1,4-glucosidase in leukocytes, the enzyme defect in glycogen storage disease Type II (Pompe disease). The procedure requires smaller volumes of blood and less time than previous methods. The assay involves the separation of leukocytes by Peter's method for beta-glucosidase and a modification of Salafsky and Nadler's fluorometric method for alpha-glucosidase.

Phenotypes of galactosaemia in infants screened at birth

Five genetic forms of galactosaemia were found in 15 infants identified in a newborn screening programme through a combination of laboratory criteria, involving serial assays of transferase and interpretation of isozyme patterns. The biochemical phenotypes of some infants were ascertained only weeks after birth, when transferase activities had increased from initial levels.

Haemoglobin J in the French Canadian

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L-ascorbic acid biosynthesis in higher plants from L-gulono-1, 4-lactone and L-galactono-1, 4-lactone

Detached bean (Phaseolus vulgaris) and strawberry (Fragaria) fruits fed l-gulono-1,4-lactone or l-galactono-1,4-lactone convert this compound, in part, to l-ascorbic acid. When l-galactono-1,4-lactone is given as a 0.25% solution to detached bean shoots, the ascorbic acid content is tripled in less than 10 hours. l-Gulono-1,4-lactone is only 5 to 10% as effective as its epimer. Experiments with specifically labeled l-gulono-1,4-lactone and l-galactono-1,4-lactone prove that conversion is direct. Ascorbic acid is labeled at the same carbon as its precursor.A method is described for preparation of l-galactono-1,4-lactone-2-(14)C from myo-inositol-2-(14)C. This method can be extended to the preparation of l-ascorbic acid-2-(14)C on the basis of results obtained in the present study.

Chromosome 15 abnormality in a mentally retarded adult

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