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Biomedical subjects

J M Sands

Publications and source records attributed to J M Sands.

82 records · Page 5Linked to original sources

Dominantly inherited cardioskeletal myopathy with lysosomal glycogen storage and normal acid maltase levels.

A family is presented in which 7 members over 3 generations were affected by cardioskeletal myopathy. A vacuolar myopathy with excessive free and intralysosomal glycogen storage in skeletal and cardiac striated muscle was identified in biopsy studies. Post-mortem studies in several patients revealed changes of a congestive cardiomyopathy with myocardial fibrosis. Acid maltase, phosphorylase, debrancher and lysosomal enzyme screens, and glycolytic enzyme levels in skeletal muscle, were normal in 1 case. This is the third report of non-acid maltase deficient lysosomal glycogen storage disease and adds to previous reports with the presentation of detailed family studies, examined of ante- and post-mortem cardiac histology and reports of detailed glycolytic and lysosomal enzyme analysis. This syndrome is unusual among glycogenoses in having a dominant inheritance pattern.

Adult↗

Na-K-Cl cotransport in apical membrane of rabbit renal papillary surface epithelium.

The renal papillary surface epithelium is exposed to pelvic urine on its apical surface and to inner medullary interstitium on its basolateral surface. To investigate transport in this epithelium, we dissected it free from the renal papilla of rabbits and mounted it in a chamber that allowed both sides to be bathed independently. Cell volume was measured at 25 degrees C utilizing computerized quantitative microscopy. Addition of ouabain (10(-4) M) to the basolateral solution induced a 20% volume increase. This volume increase was completely inhibited by the removal of apical bath NaCl, Na+, K+, or Cl- but not by the removal of urea. Bumetanide, down to 10(-9) M in the apical bath, completely inhibited the ouabain-induced swelling. Changes in apical bath osmolality, resulting from addition or removal of NaCl, caused cell volume changes that were greater than could be accounted for by osmotic water flow alone. This hyperresponse was blocked by bumetanide and was stimulated by vasopressin (10(-8) M). These observations are consistent with the presence of Na-K-ATPase in the basolateral membrane and a bumetanide-sensitive, vasopressin-responsive Na-K-Cl co-transporter in the apical membrane.

Animals↗

Transmembrane potential of renal papillary epithelial cells: effect of urea and DDAVP.

To define how renal papillary epithelial cells respond to wide changes in the ionic and osmotic composition of their environment, measurements were made of the transmembrane potential differences (PD) of rat renal papillary epithelial cells in vitro in media containing 100 mM NaCl, 100 mM KCl, 1.5 mM CaCl2, and 1 mM MgSO4 plus varying amounts of urea and/or sucrose up to 1,400 mM. Glass microelectrodes (resistance 25-75 M Omega) were used. With added sucrose, no change in PD from the initial value of -9.3 +/- 1.3 (SD) mV (n = 29) (cell interior negative) was found. With added urea, alone or while osmolality was maintained nearly constant with sucrose, the PD changed in a triphasic manner, depolarizing to -5.3 mV at 50 mM urea, hyperpolarizing to -20.0 mV at 150 mM urea, and then depolarizing again to -5.5 mV at 1,400 mM urea. When bath potassium was decreased to 10 meQ/liter (choline replacement) the PD hyperpolarized to -46.9 +/- 5.0 (SD) mV (n = 32). DDAVP, a nonpressor vasopressin analogue, and 8-bromo-cAMP depolarized the membrane to -5 mV in the presence of urea but did not change PD when urea was absent. These observations suggest an interaction between urea and ionic movement or conductance in rat renal papillary epithelial cells.

Animals↗

Disseminated infection caused by Cunninghamella bertholletiae in a patient with beta-thalassemia. Case report and review of the literature.

Rare cases of acute mucormycosis in immunocompromised persons have been attributed to Cunninghamella bertholletiae. We report the first known case of this organism causing a chronic, indolent, systemic disease clinically similar to entomophthoramycosis. Cunninghamella bertholletiae is an opportunistic pathogen whose morbidity may be underappreciated because it is usually considered to be a laboratory contaminant.

Adult↗

Response of right ventricular ejection fraction to upright bicycle exercise in coronary artery disease.

The right ventricular (RV) response to exercise was assessed in 32 patients with angiographically documented coronary artery disease and in 14 normal controls without cardiopulmonary disease. The relationships between exercise RV reserve, exercise left ventricular (LV) reserve, and the presence of proximal right coronary stenosis were also evaluated. RV and LV ejection fractions were determined using first-pass radionuclide angiocardiograms. The normal response to exercise was at least a 5% absolute increase in RV and LV ejection fractions. In the group with coronary artery disease, RV ejection fraction either decreased or remained the same with exercise (abnormal exercise RV reserve) in 19 of 32 patients. LV exercise reserve was abnormal in 26 of 32 patients. All 19 patients with abnormal exercise RV reserve had abnormal exercise LV reserve, and all six patients with normal LV reserve had normal RV reserve. There was a significant linear relationship between the direction and magnitude of change from rest to exercise of LV ejection fraction and RV ejection fraction (r = 0.77). In contrast, the RV response to exercise was not primarily dependent upon the presence or absence of proximal right coronary stenosis. These data suggest that abnormal exercise RV reserve occurs frequently in coronary artery disease and that the concomitant LV response to exercise appears to be its major determinant.

Adult↗

Henbane chewing.

A case is presented of deliberate chewing of the flowers of henbane (Hyoscyamus niger) in the hope of producing euphoria, and an account is given of the poisoning so produced. The case indicates a more widespread use of this plant among the drug-taking community of Australia, and discussion of the case includes a description of the plant and an outline of treatment for the acute stage of the poisoning.

Adult↗