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)

From numerous publications on the "prophylactic" and "therapeutic" use of vitamin E, it may be concluded that the toxicity of vitamin E is very low. It has been demonstrated in animal experiments that vitamin E has neither mutagenic, teratogenic nor carcinogenic properties. Based on studies in humans, a daily dosage of 100-300 mg vitamin E can be considered harmless from a toxicological point of view. Using double-blind studies involving a large number of subjects, it has been demonstrated that large oral doses of up to 3,200 USP-Units/day led to no consistent adverse effects. From a large body of published data, dosage ranges have been deduced which can be characterized as safe for human subjects even where their use extends over a long period of time. It should, however, be noted that oral intake of high levels of vitamin E can exacerbate the blood coagulation defect of vitamin K deficiency caused by malabsorption or anticoagulant therapy. High levels of vitamin E intake are, therefore, contraindicated in these subjects.
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PMID:Tolerance and safety of vitamin E: a toxicological position report. 162 54

The use of small amounts of a dilute solution of heparin (less than or equal to 100 IU) to keep indwelling intravenous needles or catheters patent for intermittent venous access either for intravenous therapy or timed blood sampling is a common clinical practice. It is considered safe since the amount of heparin required is much less than that required for heparinization. Herein, we describe a 13-yr-old patient with malabsorption who developed clinically significant bleeding shortly after a diagnostic test which required multiple small injections of heparin for intermittent venous access (total amount of heparin administered was 600 units over 5 hr). The coagulopathy was corrected by a single dose (10 mg) of parenteral vitamin K. As our patient had multiple risk factors for the development of vitamin K deficiency including malabsorption, decreased food intake, and antibiotic use, we postulate that the small amount of heparin precipitated the coagulopathy by increasing the antiprotease activity of antithrombin III on abnormal factors X and II formed in the vitamin K deficient state. We would therefore recommend administration of vitamin K to patients who are at risk of developing vitamin K deficiency before using even small amounts of heparin.
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PMID:Hazards of small amounts of heparin in a patient with subclinical vitamin K deficiency. 250 46

Vitamin K catalyzes the post-translational carboxylation of coagulation proteins C, S, and factors II, VII, XI, and X. Detection of the noncarboxylated forms allows an indirect and specific measure of the vitamin K deficiency found in early, classic, and late hemorrhagic disease of the newborn (HDN), malabsorption syndromes, and drug related (warfarin, anticonvulsants, and antibiotics) states. Idiopathic late HDN (CNS bleeding) occurs in exclusively breast-fed infants and is prevented by appropriate parenteral and oral vitamin K prophylaxis given at birth. All newborn infants and older infants with malabsorption syndromes should receive prophylactic vitamin K.
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PMID:New insights on vitamin K. 332 79

Four cases of extrahepatic biliary atresia are reported. Each of these infants presented with haemorrhagic phenomena rather than with prolonged jaundice. The increased bleeding tendency was due to a vitamin K deficiency, probably caused by cholestasis-induced malabsorption. Therefore extrahepatic biliary atresia should be considered in each infant with a bleeding diathesis.
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PMID:Bleeding as the first symptom of extrahepatic biliary atresia. 349 31

A coagulopathy due to vitamin K deficiency was discovered in 42 hospitalized patients, most of whom had been misdiagnosed as having disseminated intravascular coagulation. Factors contributing to vitamin deficiency included inadequate diet, malabsorption, failure of physicians to prescribe vitamin K supplements, antibiotic therapy, renal insufficiency, hepatic dysfunction, recent major surgery, and possibly pregnancy. Sixteen patients (34%) bled sufficiently to need red blood cell transfusions and ten patients (24%) ultimately died. Of 18 patients who also had thrombocytopenia, three did have disseminated intravascular coagulation. The deficiency, a contributor to morbidity and mortality, can be prevented by prophylactic administration of vitamin K to severely ill patients who are eating inadequately and receiving antibiotics.
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PMID:Coagulopathy caused by vitamin K deficiency in critically ill, hospitalized patients. 365 2

The clinical, biochemical, and histological features of 27 children with syndromic paucity of the interlobular bile ducts are described. All presented in the first 5 months of life, 21 with jaundice, two with spontaneous bleeding due to vitamin K malabsorption in addition to jaundice, two with pruritus, and two with failure to thrive. Interlobular bile ducts were abundant in liver biopsies from five (18% of cases) in the first 6 months of life. The degree of portal fibrosis and cellular infiltrate was mild in all except three patients. Clinically significant heart lesions occurred in 52% but only 22% had peripheral pulmonary stenosis. Characteristic facial appearances were present in only 70%; embryotoxon and vertebral anomalies were present in 56 and 33%, respectively. Two infants died of cardiovascular complications, one of alimentary bleeding and one of progressive liver disease. Complications of vitamin K deficiency occurred in 15%, vitamin D deficiency in 30%, and vitamin E deficiency in 37%. Survivors at ages of 19 months to 16.5 years had considerable morbidity with pruritus occurring in 70%, jaundice in 48%, xanthomas in 30%, 74% having hepatomegaly and 63% splenomegaly. All had abnormal biochemical tests of liver function, 90% had growth retardation, and 50% developmental delay. We conclude that differentiation from extrahepatic biliary atresia can be difficult if biliary flow cannot be demonstrated. Prevention of fat-soluble vitamin deficiency is essential. Further research is required to decrease the morbidity associated with this syndrome in infancy.
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PMID:Syndromic paucity of the intrahepatic bile ducts: diagnostic difficulty; severe morbidity throughout early childhood. 368 72

A male born to first cousins presented at 12 months with hypocalcemic convulsions, rickets, epistaxis due to vitamin K deficiency, and extremely low serum levels of beta-carotene and vitamin A. Liver function was altered moderately (glutamic-oxaloacetic transaminase, 55 U/L; glutamic-pyruvic transaminase, 37 U/L; lactate dehydrogenase, 255 U/L; alkaline phosphatase, 437 U/L). To correct the deficiencies, 8,000 IU vitamin D/day, 10,000 IU vitamin A/day, and intramuscular administration of vitamin K1 were required. At 9 years, he presented signs of neuromuscular affection, and the serum vitamin E level (measured for the first time) was extremely low. Classic lipid malabsorption syndromes (abetalipoproteinemia, chronic cholestasis, mucoviscidosis, coeliac disease, Whipple's disease) were excluded by appropriate examinations. Composition of duodenal bile acids was characterized by undetectable levels of cholic acid metabolites, and only chenodeoxycholic acid metabolites were present. Serum total bile acid concentration was normal, with an atypical low cholic acid/chenodeoxycholic acid ratio and abnormal presence of 3 beta-OH-delta 5-cholenic acid and 6-OH-bile acids. Urinary bile acid composition was also characterized by elevated 6-OH-bile acids. Known enzymopathies of the bile acid synthetic pathway were excluded (cerebrotendinous xanthomatosis, cerebro-hepato-renal syndrome of Zellweger, coprostanic acidemia). Bile acid pool sizes were determined by using stable isotopes: cholic acid pool size [2.90 (N, 32 +/- 16) microM/kg] and chenodeoxycholic acid pool size [10.8 (N, 32.6 +/- 9.9) microM/kg] were extremely low; fractional turnover rates of both bile acids were in a normal range.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Malabsorption of liposoluble vitamins in a child with bile acid deficiency. 379 31

An outline has been given of the major abnormalities of coagulation which can occur secondary to diseases in previously normal individuals. First, the disorders due to deficiency of the vitamin K-dependent clotting factors are described. Vitamin K deficiency can occur in the newborn, or at later stages in life when there is intestinal malabsorption. The malabsorption disorders, such as coeliac disease, together with major abdominal surgery or prolonged use of broad-spectrum antibiotics can give rise to vitamin K deficiency. Additionally, in obstructive jaundice the lack of secretion of bile salts into the upper intestine causes vitamin K malabsorption. The use of oral anticoagulants is associated with haemorrhage in a small proportion of patients. These patients usually have an excessively prolonged prothrombin time, due to overdosage with anticoagulants, but occasionally haemorrhage can occur from a localized bleeding site, such as a duodenal ulcer, in patients under good anticoagulant control. The large number of drugs which can interact with anticoagulants are listed, from which it can be seen that careful monitoring of all patients on oral anticoagulants must be carried out. The haemostatic defects associated with liver disease are then tabulated. In this situation abnormalities may be due to deficient synthesis of coagulation factors in hepatocellular failure, by failure of vitamin K absorption, and also by disseminated intravascular coagulation (DIC). DIC occurs in hepatocellular failure, because the liver cells are normally responsible for clearing activated products of the coagulation and fibrinolytic enzyme systems. The presence of clinical haemorrhage and haemostatic breakdown in hepatic disease usually indicates a serious prognosis, but appropriate replacement therapy is indicated in this situation. Disseminated intravascular coagulation embraces a large number of clinical haemorrhagic syndromes, where intravascular activation of the coagulation system takes place accompanied by compensatory fibrinolytic activity. DIC can be initiated by intravascular release of procoagulant substances, such as tissue thromboplastin, or by damage to vascular endothelium and platelets. The main clinical conditions associated with DIC comprise the severe infections and septicaemias, obstetric accidents, shock and trauma, neoplasia and snake-bite envenoming. In all instances, the pathophysiological disorder of haemostasis is managed by treating the underlying disease.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Acquired coagulation disorders. 389 41

A 15-month-old girl from Coimbra (Portugal) had a history of numerous hemorrhagic episodes with multiple bruises, hematomas but not hemarthroses. On serial testing she showed deficiency of factors II, VII, IX, X and protein C. Malabsorption-induced vitamin K deficiency, liver disease or ingestion of a coumarin compound were excluded. An absence of detectable abnormalities was found among her relatives. Consanguinity was not present. The immunologic assay, immunoelectrophoresis or antibody neutralization, revealed much higher levels of these factors than the clotting assay. The non-physiological activator (Echis carinatus venom) produced higher levels of prothrombin activation than those detected by physiological activation. Two-dimensional immunoelectrophoresis of the patient's plasma in calcium showed that prothrombin had the same mobility as acarboxyprothrombin. No significant response to large doses of intravenous vitamin K3 (6 mg) was observed. Transfusion of 120 ml of frozen fresh plasma led to an immediate increase in the procoagulant activities of vitamin K dependent protein, similar to that found after perfusion of plasma plus vitamin K3. The results obtained from this patient suggest a defect in the gammacarboxylation mechanism inside the hepatocyte.
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PMID:Congenital deficiency of vitamin K-dependent coagulation factors and protein C. 654 83

Vitamin K (phylloquinone, K1; menaquinone, K2) functions as an essential cofactor for the synthesis of the coagulation protein factors II, VII, IX, X and protein C and S by promoting a unique post-translational modification of specific glutamic acid residues to gamma-carboxylglutamic acid, thus mediating calcium binding to phospholipid surfaces. Vitamin K deficiency results in a depletion of liver stores of phylloquinone, decreased plasma levels of vitamin K1, increased levels of K1 epoxide, appearance of noncarboxylated protein (PIVKA), decreased levels of functioning vitamin K-dependent clotting factors and prolongation of the APTT, PT and thrombotest. When the progression of deficiency leads to abnormal clotting tests a generalized bleeding tendency occurs. Noncarboxylated prothrombin (PIVKA-II) determinations are a sensitive indicator of vitamin K deficiency. Although Vitamin K deficiency can occur at any age (warfarin, fasting, antibiotic therapy, malabsorption syndromes) the major public health problem is related to prevention of early, classic and late hemorrhagic disease of the newborn (HDN). A single dose of oral or parenteral vitamin K prevents classic HDN but the most effective way to prevent early HDN is by giving large doses to the mother prior to delivery (2 weeks). Late HDN in breastfed infant occurs with a prevalence of about 20 per 100,000 live births when no neonatal prophylaxis is given. Parenteral (1 mg) K1 prevents late HDN and single or repeated doses of oral vitamin K reduces the incidence but does not eliminate all late HDN. The optimal (cost, feasibility, effective) mode of neonatal prophylaxis remains to be determined.
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PMID:Vitamin K deficiency. 788 7


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