Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abetalipoproteinaemia (ABLP) was diagnosed in a brother and sister, 9 and 13 years old, presenting with symptoms of malabsorption during the neonatal period. Both children showed most of the main clinical features of ABLP, including neurological, and ophthalmic symptoms, and mental retardation. Acanthocytosis of erythrocytes was almost complete in the affected children, while in most of the remaining 11 members of their three-generation family, it was found in less than 50% of red blood cells. Absence of apoprotein B and low concentrations of apo A-I and lipids were found only in ABLP-affected children. Among five siblings only the two affected children had ABLP-characteristic lipid storage in enterocytes. The latter features correlated better with clinical symptoms than did the acanthocytosis of erythrocytes.
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PMID:A case of abetalipoproteinaemia in a Polish family. 204 Mar 53

Jejunal mucosa is responsible for the absorption of triglycerides and the production of lipoproteins [chylomicrons, very-low-density lipoprotein (VLDL), high-density lipoprotein (HDL)] and apolipoproteins (B-48, A-I, A-II, A-IV, C-II). Mucosal damage is known to cause fat malabsorption and probably also affects the serum lipid profile. To determine lipoprotein production in states of enterocyte dysfunction, we compared the serum lipid profiles in a group of 12 children with untreated celiac disease (flat jejunal mucosa) with the profiles in a control group of 10 children suffering from other intestinal diseases. Statistically significant differences were found in the following parameters (celiac versus control): plasma levels of triglycerides (70 versus 119 mg/dl), cholesterol content in LDL (107 versus 67.7 mg/dl), protein content in VLDL (6 versus 10 mg/dl), and level of apoprotein A-I (112 versus 140 mg/dl). No significant differences were found between the two groups in the serum levels of total cholesterol, the cholesterol content in VLDL and HDL, the protein content in LDL and HDL, and the level of apoprotein B. Following institution of a gluten-free diet, the lipoprotein profile reverted to normal. These data suggest that the changes in the serum lipoprotein profile in celiac disease are secondary to alterations in enterocyte function and not only a reflection of fat malabsorption.
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PMID:Serum lipoprotein profile in children with celiac disease. 238 34

A plant sterol, sitosterol, was quantitated in very low density lipoproteins (VLDL), low density lipoproteins (LDL) and high density lipoproteins (HDL) and related to faecal steroids and cholesterol absorption in heterozygous familial hypercholesterolaemia patients with (n = 7) and without ileal bypass (n = 6). The latter had resulted in severe bile acid malabsorption but fractional cholesterol absorption was within low control limits. Serum total and LDL cholesterol and apoprotein B levels were reduced, whereas HDL cholesterol, apoprotein A-I, VLDL and HDL sitosterol concentrations were increased by the ileal exclusion, and the increase in LDL and serum total sitosterol levels was insignificant. In terms of mmol/mol of cholesterol or apoprotein B, however, the LDL and total sitosterol contents were higher in the subjects who had undergone operation. For an unknown reason the sitosterol content increased gradually within the lipoprotein particles from the lighter to the heavier lipoproteins, and the enrichment was similar in the two groups. Dietary sitosterol intake, indicated by faecal sitosterol excretion, was similar in the two groups. The contents of serum total and LDL sitosterol were positively correlated with the dietary sitosterol intake in both groups, and with the fractional cholesterol absorption only in the group not subject to operation. These associations were less consistent for sitosterol contents in other lipoproteins. We conclude that normally the serum sitosterol content reflects cholesterol absorption efficiency even in patients with familial hypercholesterolaemia, provided the dietary sitosterol intake is quite constant. In addition, for unknown reasons ileal exclusion leads to an increased lipoprotein sitosterol content.
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PMID:Effect of ileal exclusion on lipoprotein sitosterol in familial hypercholesterolaemia. 335 98

We describe two siblings with fat malabsorption and jejunal chylomicron retention. Plasma lipoproteins were studied in the patients and their first-degree relatives. The patients were a 14-year-old girl and her 8-year-old brother. Compared to healthy controls, they both had low fasting plasma concentrations of plasma total, HDL, and LDL cholesterol, as well as of apolipoproteins A-I and B. No increase in plasma lipoprotein levels or detectable apo B-48 was observed following an oral fat load. Histological studies of jejunal biopsy specimens obtained during fasting and 1 h postprandially showed severe steatosis, and an apparent block of chylomicron secretion from the endoplasmic reticulum into the Golgi apparatus was observed by electron microscopy. Liver biopsy specimens showed moderate steatosis and ultrastructural changes similar to those in the enterocytes. One healthy sister had a normal plasma lipoprotein pattern, and showed increased plasma triglyceride levels as well as the presence of apo B-48 following an oral fat load. Both parents had normal plasma total cholesterol levels, but clearly reduced fasting concentrations of HDL cholesterol and apo A-I. At least in this family, determination of plasma apo A-I levels might thus prove useful in the identification of heterozygotes.
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PMID:Studies on lipoprotein metabolism in a family with jejunal chylomicron retention. 760 Dec 3

Liver disease is accompanied by major qualitative and quantitative disturbances in plasma lipoprotein metabolism, the extent and intensity of which depend on the degree of parenchymal damage, cholestasis, or both. The main objective of this study was to determine the cholesteryl ester transfer CETP activity and its association with the lipoprotein neutral lipid composition in patients with either liver cirrhosis or cholestasis, as compared to normal controls. Lipoproteins were isolated by ultracentrifugation, lipids and apolipoproteins were measured by conventional methods, and the fatty acid composition was established by gas chromatography; CETP activity in lipoprotein-deficient plasma was measured by determining the transfer of [3H]cholesteryl esters from HDL to VLDL. Lipoprotein lipase and hepatic lipase activities were measured in post-heparin plasma by radiochemical methods. In patients with liver cirrhosis, low levels of VLDL, HDL, apo B, and Lp(a) were observed, as well as a change in the composition of HDL particles, with increases in the relative proportion of triglyceride and free cholesterol. Respectively, the last two changes could be attributed in part to the low hepatic lipase activity observed in this study, and to the low lecithin:cholesterol acyltransferase activity previously observed by others. In patients with cholestasis, a moderate hyperlipidemia due to the elevation of LDL was found. In contrast, HDL and apo A-I levels were very low reflecting a low number of HDL particles, which also had altered compositions with increases in the triglyceride and free cholesterol contents relative to apo A-I and esterified cholesterol, respectively. As regards the fatty acid composition of lipoprotein lipids, the two groups of patients showed, in general, a lower proportion of linoleic acid and a compensating higher proportion of oleic acid as compared to the controls, changes that were observed in both cholesteryl esters and triglycerides. In contrast, the proportions of oleic and palmitoleic acids in phospholipids were increased, whereas that of stearic acid was decreased in patients as compared to controls. In patients with liver cirrhosis, as well as in controls, no changes were observed in the fatty acid compositions of cholesteryl ester, triglycerides, or phospholipids among the different lipoproteins, which probably reflects the equilibration reached by the action of CETP. In patients with cholestasis, no differences were observed in fatty acid composition among the lipoprotein phospholipids but, interestingly, cholesteryl esters from VLDL had a significantly lower linoleic acid content than those from HDL, whereas triglycerides from VLDL had significantly higher oleic acid and lower linoleic acid contents than those from HDL. This distinct fatty acid composition of the neutral lipids between lipoproteins was associated with a significant decrease (25%) in the cholesteryl ester transfer activity in patients with cholestasis. We suggest that fat malabsorption due to the biliary defect may induce a decrease in cholesteryl ester transfer protein synthesis or section, which in turn would slow the equilibration of the neutral lipids among plasma lipoproteins.
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PMID:Cholesteryl ester transfer activity in liver disease and cholestasis, and its relation with fatty acid composition of lipoprotein lipids. 874 May 80

Our purpose is to provide a framework for diagnosing the inherited causes of marked high-density lipoprotein (HDL) deficiency (HDL cholesterol levels <10 mg/dL in the absence of severe hypertriglyceridemia or liver disease) and to provide information about coronary heart disease (CHD) risk for such cases. Published articles in the literature on severe HDL deficiencies were used as sources. If apolipoprotein (Apo) A-I is not present in plasma, then three forms of ApoA-I deficiency, all with premature CHD,and normal low-density lipoprotein (LDL) cholesterol levels have been described: ApoA-I/C-III/A-IV deficiency with fat malabsorption, ApoA-I/C-III deficiency with planar xanthomas, and ApoA-I deficiency with planar and tubero-eruptive xanthomas (pictured in this review for the first time). If ApoA-I is present in plasma at a concentration <10 mg/dL, with LDL cholesterol that is about 50% of normal and mild hypertriglyceridemia, a possible diagnosis is Tangier disease due to mutations at the adenosine triphosphate binding cassette protein A1 (ABCA1) gene locus. These patients may develop premature CHD and peripheral neuropathy, and have evidence of cholesteryl ester-laden macrophages in their liver, spleen, tonsils, and Schwann cells, as well as other tissues. The third form of severe HDL deficiency is characterized by plasma ApoA-I levels <40 mg/dL, moderate hypertriglyceridemia, and decreased LDL cholesterol, and the finding that most of the cholesterol in plasma is in the free rather than the esterified form, due to a deficiency in lecithin:cholesterol acyltransferase activity. These patients have marked corneal opacification and splenomegaly, and are at increased risk of developing renal failure, but have no clear evidence of premature CHD. Marked HDL deficiency has different etiologies and is generally associated with early CHD risk.
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PMID:Clinical presentation, laboratory values, and coronary heart disease risk in marked high-density lipoprotein-deficiency states. 2129 40