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Biomedical subjects

J B Simon

Publications and source records attributed to J B Simon.

At least 37 records · Page 2Linked to original sources
PubMed1979

Selective superior mesenteric embolization for small intestinal hemorrhage.

A 25-year-old white woman who had previously undergone two operations for peptic ulcer disease, and was addicted to drugs and alcohol, had massive hemorrhage from the small intestine. Angiography pinpointed the jejunum as the source of bleeding. Because the patient had a coagulopathy she was considered a poor risk for surgery. Bleeding was controlled by embolization with sterile, commercially available Gelfoam (Upjohn) which was injected into the offending branch of the superior mesenteric artery. This is believed to be only the third documented case of embolization of small intestinal vessels. A review of the available literature is presented and the value of Gelfoam embolization as an adjunct in the control of hemorrhage in selected patients is stressed.

Adult↗
PubMed1978

Lipoprotein-X levels in extrahepatic versus intrahepatic cholestasis.

Lipoprotein-X (LP-X) is an abnormal lipoprotein characteristic of cholestasis. To assess recent claims that its serum concentration helps differentiate extrahepatic from intrahepatic cholestasis, we studied 42 consecutive LP-X-positive patients. The mean serum LP-X level was higher in 18 patients with extrahepatic obstruction than in 24 with intrahepatic cholestatis, 321 +/- 89 versus 130 +/- 31 SEM mg per dl (P less than 0.05). However, values overlapped in 38 of the 42 cases, and in the other 4 the diagnosis of extrahepatic obstruction was obvious anyway from clinical examination. LP-X concentration gave little more information than did free cholesterol of phospholipid levels, which it closely paralleled (r = 0.89 and 0.81, respectively, P less than 0.01). There was no correlation with standard liver function tests or with activity of lecithin-cholesterol acyltransferase, the enzyme responsible for cholesterol esterification in plasma. Contrary to recent claims, these findings suggest that serum LP-X quantitation has little or no clinical value in distinguishing extrahepatic from intrahepatic cholestasis.

Cholestasis↗
PubMed1978

Hepatic cholesterol ester hydrolase in human liver disease.

Human liver contains an acid cholesterol ester hydrolase (CEH) of presumed lysosomal origin, but its significance is unknown. We developed a modified CEH radioassay suitable for needle biopsy specimens and measured hepatic activity of this enzyme in 69 patients undergoing percutaneous liver biopsy. Histologically normal livers hydrolyzed 5.80 +/- 0.78 SEM mumoles of cholesterol ester per hr per g of liver protein (n, 10). Values were similar in alcoholic liver disease (n, 17), obstructive jaundice (n, 9), and miscellaneous hepatic disorders (n, 21). In contrast, mean hepatic CEH activity was more than 3-fold elevated in 12 patients with acute hepatitis, 21.05 +/- 2.45 SEM mumoles per hr per g of protein (P less than 0.01). In 2 patients studied serially, CEH returned to normal as hepatitis resolved. CEH activity in all patients paralleled SGOT levels (r, 0.84; P less than 0.01). There was no correlation with serum levels of free or esterified cholesterol nor with serum activity of lecithin-cholesterol acyltransferase, the enzyme responsible for cholesterol esterification in plasma. These studies confirm the presence of CEH activity in human liver and show markedly increased activity in acute hepatitis. The pathogenesis and clinical significance of altered hepatic CEH activity in liver disease require further study.

Acute Disease↗
PubMed1978

Studies on human hepatic cholesterol ester hydrolase in liver disease.

Stokke has described a lysosomal cholesterol ester hydrolase (CEH) in human liver. To clarify the significance of this enzyme, we first modified Stokke's assay to enable CEH determination in hepatic needle biopsies. Studies established optimal pH of 4.6--5.2 and linearity of hydrolysis for at least 12 hours, using homogenates containing about 2 mg liver and radiolabeled cholesterol oleate as substrate. The assay was then applied to patients undergoing percutaneous needle biopsy. Hepatic CEH activity in alcoholic liver disease, obstructive jaundice and a variety of other hepatic disorders was not significantly different from that in histologically normal livers. In patients with acute hepatitis, however, mean CEH activity was more than 3-fold increased (P less than 0.01). Values paralleled SGOT levels, returned to normal as hepatitis resolved, and were unrelated to serum cholesterol levels or to lecithin:cholesterol acyltransferase activity. In contrast to CEH, activity of acid phosphatase, a standard lysosomal marker enzyme, was the same in hepatitic as in normal livers. We conclude that CEH can be assayed in needle biopsies of human liver, that its activity increases in acute hepatitis, and that this is probably not simply due to a nonspecific general increase in lysosmal enzymes.

Acid Phosphatase↗
PubMed1975

Cholesterol ester hydrolase in human red blood cells.

1. Cholesterol ester hydrolytic activity (sterol-ester hydrolase EC 3.1.1.13) was detected in human red blood cells. Enzyme activity appeared confined to the cell membrane and was most marked in washed preparations of red cell ghosts. 2. Hydrolytic activity was stimulated by the anti-oxidants D-alpha-tocopherol and butylated hydroxytoluene. Marked inhibition was produced by erythrocyte hemolysate, sodium taurocholate, and Triton X-100. 3. Optimal pH for the reaction was 5.4--5.7. 4. Because red cell cholesterol is all unesterified, it is speculated that the hydrolase serves to maintain the erythrocyte membrane free of esterified cholesterol.

Butylated Hydroxytoluene↗
PubMed1975

Distribution of storage iron as body stores expand in patients with hemochromatosis.

The relative distribution of storage iron between bone marrow and liver has not been adequately studied in patients with iron-loading disorders. To help clarify this we assessed iron metabolism in patients with iron overload and in control subjects with cirrhosis but no excess body iron. In 4 patients with advanced iron overload studied late in the course of their illness, excess hemosiderin was present in both bone marrow and liver, as expected. In contrast, 2 patients with idiopathic hemochromatosis whose excess iron had been depleted by phlebotomy subsequently developed progressive hepatic parenchymal and reticuloendothelial (RE) deposition of iron, yet marrow hemosiderin remained sparse. Moreover, surface radioactivity over the liver after an oral dose of 59Fe. These results suggest that during the initial stages of hemochromatosis there is a dissociation in the rate of iron accumulation between the bone marrow and liver. Excess hemosiderin appears to be deposited predominantly and preferentially in hepatic storage sites until the later stages of the disease.

Aged↗
PubMed1975

Fate of ingested hepatitis B antigen in blood-sucking insects.

The fate of ingested hepatitis B antigen (HBsAg) in two mosquito species and two Hemiptera species was compared with the rate of blood meal digestion by these insects. In both mosquito species HBsAg was detected by radioimmunoassay for only a few hours after ingestion, disappearing well before the time of blood meal digestion. Production of a protease by the mosquito midgut may have been responsible for destruction of the antigen. In contrast, in the bedbug HBsAg remained detectable throughout a 5-week testing period. Moreover, titers rose during the last week, when blood meal digestion was complete, suggesting possible replication of the antigen. At no time was antigen detected in eggs or feces of any species tested, but juvenile bedbugs fed HBsAg when in the fourth or fifth instar stage still contained antigen after molting. These studies suggest that bedbugs may potentially be a more dangerous source of hepatitis B transmission than mosquitoes.

Animals↗