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)

There are two sources of vitamin D available to man: The more important source is the cholecalciferol (vitamin D3), which is produced photochemically in the skin from the provitamin, 7-dehydrocholesterol; vitamin D ingested with food is of secondary importance, but assumes a critical role when an individual is deprived of solar exposure. Vitamin D therefore is not strictly a vitamin. A deficiency of vitamin D ultimately results in osteomalacia in adults and rickets in children, and provision of sunlight or small oral doses of the vitamin can cure this bone condition. There are, however, many less common conditions in which small doses of the vitamin are ineffective, whereas larger doses of vitamin D can achieve healing of the bone disease. These conditions are collectively called vitamin D-resistant diseases and include hypoparathyroidism, genetic and acquired hypophosphataemic osteomalacias, renal osteodystrophy, vitamin D-dependent rickets, and the osteomalacia associated with liver disease and intestinal malabsorption. Unfortunately, large doses of vitamin D continue to be prescribed for a wide variety of diseases in which there is little scientific evidence of their efficacy. The benefits and dangers of high doses of vitamin D are discussed and the problems arising from inappropriate or poorly supervised treatment with vitamin D presented. The serum concentration of the active metabolite of vitamin D, 1,25 dihydroxyvitamin D is increased in certain disease states, and the pathophysiology of some these diseases are presented. The exciting developments in tumour differentiation and the role of high doses of 1,25 dihydroxyvitamin D for the control of leukaemia and other blood and skin diseases are discussed.
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PMID:High-dose vitamin D therapy: indications, benefits and hazards. 250 9

Electrolytic imbalance is a frequent finding in malabsorption syndrome. Derangement of calcium metabolism present clinically in different variants is most serious. Some patients develop hypocalcemia manifesting clinically with specific myasthenia, paresthesias, convulsions, hemorrhages, etc. In other variants severe skeletal lesions are seen which may become dominating in the clinical picture though hypocalcemia was absent. Investigation of calcium metabolism, hormonal profile (parathormone, in particular) in malabsorption syndrome can prognosticate and prevent the onset of osteomalacia.
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PMID:[Osteopathy in malabsorption syndromes]. 261 13

Calcium deficiency causes osteoporosis in experimental animals because the skeleton is sacrificed for the preservation of the plasma (ionic) calcium and to meet obligatory calcium losses in the feces and urine. (Vitamin D deficiency, on the other hand, causes rickets and osteomalacia largely because of the loss of the calcemic action of vitamin D, which leads to hypocalcemia, secondary hyperparathyroidism, and hypophosphatemia.) The concept that human osteoporosis, particularly in postmenopausal women, results from negative calcium balance represents a working hypothesis that fits many, but not all of the available data. In normal women, the crucial event is a rise in obligatory urinary calcium loss, which may result from an increase in the complexed fraction of the plasma calcium, due in turn to an increase in plasma bicarbonate. Prospective trials with calcium supplements have, however, yielded conflicting results. In osteoporotic women, a further increase in urinary calcium combined with calcium malabsorption produces a further increase in bone resorption, but some impairment of bone formation due to declining androgens may constitute an additional risk factor with advancing age. The suppressibility of urinary hydroxyproline by calcium supplementation in those patients who can absorb calcium, and by calcitriol in those who cannot, supports the calcium deficiency model, but more trials are needed to establish its validity.
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PMID:The calcium deficiency model for osteoporosis. 264 3

The level of serum 25-hydroxyvitamin D (25-OH-D3) was determined in 94 cases of healthy volunteers and 98 patients with various diseases. The mean level of the controls was 16.2 +/- 4.6 ng/ml (x /- S). The patients were divided into 5 groups, 1) Osteomalacia and rickets 42 cases, showing typical changes of bone in X-ray films. In 12 of them the disease was caused by vitamin D deficiency. The mean value of 25-OH-D3 was 3.3 +/- 2.0 ng/ml, being much lower than that of controls (P less than 0.001). In 14 cases of hypophosphatemia, 8 cases of renal tubular acidosis and 8 cases of renal insufficiency all complicated with osteomalacia the mean value of 25-OH-D3 was 17.9 +/- 11.4, 18.2 +/- 9.6 and 19.2 +/- 5.6 ng/ml (P greater than 0.05) respectively. 2) Intestinal malabsorption 18 cases. The mean level of 25-OH-D3 was 4.5 +/- 3.2 ng/ml (P less than 0.001). Some of them had hypocalcemia and/or secondary hyperparathyroidism. 2 showed osteoporosis and 1 osteomalacia. 3) Chronic liver disease 24 cases, the mean value of 25-OH-D3 was 6.2 +/- 5.6 ng/ml, being much lower than that of the controls (P less than 0.001). 4) 10 cases after taking anti-epileptic drugs had a mean level of 25-OH-C3 6.9 +/- 5.8 ng/ml (P less than 0.001). 1 had X-ray evidence of osteomalacia. 5) 4 cases of overdosage of vitamin D had a mean value of 110.3 +/- 22.5 ng/ml, being much higher than that of the controls (P less than 0.001). Competitive protein binding assay for measuring 25-OH-D3 is a simple and economic method. It is sensitive and specific as it provides distinct discrimination between healthy controls and patients with vitamin D deficiency or overdosage.
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PMID:[Clinical significance of competitive protein binding assay of 25-hydroxyvitamin D concentration]. 273 43

In a retrospective study, jejunal mucosal disaccharidase and alkaline phosphatase activities have been investigated in 40 controls and patients with proven celiac sprue (n = 26), lactase deficiency (n = 26), osteoporosis or osteomalacia (n = 16), chronic pancreatitis (n = 12), giardiasis (n = 7), or Crohn's disease (n = 7). Apart from a nonselective reduction of mucosal enzyme activities in the sprue syndrome and a selective reduction of lactase activity in the patients with primary lactase deficiency, assays of mucosal disaccharidases revealed only inconstant or slight deviations from the control group and were not of diagnostic significance for any of the above-mentioned disorders. Isolated forms of enzyme deficiencies other than lactase deficiency, such as sucrase-isomaltase or trehalase deficiency were not present among 168 investigations carried out from 1972-1982. It is concluded that assay of small intestinal disaccharidase or alkaline phosphatase activities does not expand the diagnostic impact of morphological examination of small bowel biopsy specimens and modern noninvasive methods for the detection of carbohydrate malabsorption. Thus, the method does not appear a necessary or relevant investigation in routine clinical practice.
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PMID:Is the assay of disaccharidase activity in small bowel mucosal biopsy relevant for clinical gastroenterologists? 274 34

This article presents two cases of osteomalacia related to vitamin D deficiency after radiation therapy. Both patients had typical signs of serious small bowel affection with malabsorption and diarrhea, and fractures, osteoporosis, histological osteomalacia and serological vitamin D deficiency. Both patients responded to combined treatment with vitamin D, calcium, magnesium and vitamin B12. We discuss pathogenetic mechanisms, symptomatology and therapy, and review the literature. It is suggested that examination of serum 1.25 dihydroxy- and 25 hydroxy vitamin D levels be added to the diagnostic tests whenever small bowel damage after radiation is suspected.
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PMID:[Radiation injury of the intestine]. 281 76

Using a commercial kit method we obtained a vitamin D metabolite level within the normal range in a patient with biopsy-proven osteomalacia. This suggested that the ethanol extraction method employed had not removed serum factors known to falsely elevate the measurement of vitamin D metabolites. We therefore compared the levels measured after ethanol extraction and after purification by chromatography on Sep-pak C18 or Sephadex LH-20. Vitamin D metabolite levels after ethanol extraction of sera correlated with, but were higher than, those after chromatography on Sep-pak C18 cartridges (r = 0.84; 134 +/- 76 vs 76 +/- 46 nmol/l: mean +/- SD; p less than 0.01). Results were similar after chromatography on Sep-pak C18 and Sephadex LH-20 (r = 0.95; 79 +/- 46 vs 68 +/- 41 nmol/l). Sera from 5 patients (4 with osteomalacia, 1 with chronic pancreatitis/malabsorption) had vitamin D metabolite levels in the normal range after ethanol extraction but had low levels after Sep-pak C18 chromatography; four of these sera also had low levels after chromatography on Sephadex LH-20. These findings indicate that chromatography of serum on Sep-pak C18 cartridges corrects falsely elevated vitamin D metabolite levels measured by protein binding assay.
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PMID:Chromatography of serum on Sep-pak C18 corrects falsely elevated vitamin D metabolite levels measured by protein binding assay. 284 7

138 Indian patients with megaloblastic haemopoiesis were studied. All were lifelong vegetarians. The diagnosis was nutritional cobalamin deficiency in 95 and pernicious anaemia in 20; only 4 patients had folate deficiency. A third had intestinal malabsorption, 20 had features of osteomalacia, and 87 were iron deficient. Tuberculosis was diagnosed in 17. Cobalamin deficiency may have contributed to these complications via intestinal malabsorption and impaired bacterial killing of phagocytosed bacilli by cobalamin-deficient macrophages. The frequency of pernicious anaemia was the same in Indian subjects as in Caucasians.
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PMID:Megaloblastic anaemia in a vegetarian Hindu community. 286 24

Thirty-six totally depancreatectomized patients were followed up for 4-124 months. Pancreatectomy had been performed because of fulminant pancreatitis (in 10), chronic hyperalgic otherwise untractable pancreatitis (in 7), exocrine carcinoma of the pancreas (in 16), cystadenocarcinoma of the pancreas (in 2) and insulinoma (in 1). The longest survival duration was in chronic pancreatitis patients: 57 +/- 17 months. A normal socio-professional reinsertion was obtained in 16 patients, mainly those with non-malignant pancreotopathies. At the end of the survey, ten of the carcinoma patients had died, versus none in the other groups. Diabetes mellitus was characterized by the absence of ketonuria, and the frequent occurrence of hypoglycemia (in 15 patients) and infection (in 6). Malabsorption caused osteomalacia in one patient.
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PMID:Survival and rehabilitation after total pancreatectomy. A follow-up of 36 patients. 300 Aug 43

Fractures of the proximal femur are the most dangerous complications of type-II-osteoporosis with a high rate of disability and mortality. In contrast to type-I-osteoporosis, men are affected rather frequently (ratio 1:3). We report on a 79-year old man who was completely in need of care after bilateral fractures of the humerus after having survived a previous pertrochanteric fracture of the left femur. Diagnostic procedures revealed that in this case an intestinal malabsorption has to be taken into consideration as a pathogenetic factor of this severe osteopathy. Bone biopsy confirmed a combination of osteoporosis and osteomalacia. Partial gastrectomy, which had been performed 10 years before, was obviously the reason for malabsorption having caused furthermore pernicious anemia, severe malnutrition and exsiccosis.
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PMID:[Disabling senile osteoporosis]. 323 54


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