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Biomedical subjects

M D Haust

Publications and source records attributed to M D Haust.

At least 73 records · Page 4Linked to original sources
PubMed1975

Hyperornithinemia, hyperammonemia, and homocitrullinuria associated with decreased carbamyl phosphate synthetase I activity.

Six subjects from three sibships with hyperornithinemia, homocitrullinuria, and hyperammonemia are described. Assays of liver biopsy in one showed decreased CPS I and leukocyte assays indicate a similar defect in all six. Loading studies with ornithine and citrulline are consistent with a block early in the urea cycle between ornithine and citrulline. They thus support the results of the enzymatic assays. Similar studies with lysine and homocitrulline indicate there is excessive homocitrulline biosynthesis that is related to lysine intake, but there is no evidence of a block in the main lysine catabolic pathway. The younger more severely affected patients require protein restriction to 1.2 and 1.5 g/kg/24 hr to control hyperammonemia; hyperornithinemia remains unaffected. Adult subjects avoid large protein meals but tolerate a diet that is almost normal. The mode of inheritance of this disorder appears to be autosomal recessive. The fine structure of liver shows the presence of large and abnormally configurated mitochondria. There is a peculiar periodic structure situated closely to the inner mitochondrial membrane, and it is possible that the presence of this may be related to the impairment of transport of ornithine into the mitochondria; this in turn may give rise to hyperornithinemia. This disorder adds to the metabolic errors that suggest that there are close links of lysine metabolism to the urea cycle but the details are yet to be defined.

Adolescent↗
PubMed1975

The granulovesicular bodies of the arterial wall.

Small, round, membrane-bound electron-dense bodies were observed in the smooth muscle cells and the intimal and medial intercellular spaces of arteries in the dog, rat, and pig under normal and various experimental conditions. These structures, referred to as granulovesicular bodies (GVB), measured from 0.2 to 0.5 mum. in diameter and contained an inner core of granular and vesicular subunits. The intercellular and extracellular forms of the GVB were structurally similar, and in the interstitial spaces they appeared to have a definite spatial relation to the elements of elastic tissue. The GVB were more numerous under experimental than under normal conditions. It is speculated that the GVB are secretory in nature, originating from the smooth muscle cells, and may play a role in the remodeling of arterial elastic fibers.

Animals↗