Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirty lactating Holstein cows were in two groups in a study of effects of vitamin B12 injections on milk fat synthesis. All cows were fed a normal fiber diet for the first 28 days after calving and then adjusted gradually to a low fiber diet over the next 28 days. After adjustment to the low fiber diet, in a single reversal trail, cows received either 150 mg of vitamin B12 in the form of hydroxocobalamin intramuscularly every 7 days for 21 days or no treatment for 21 days. Daily milk yield (kg), percent milk fat, and milk fat yield (g) for the normal fiber, low fiber adjustment, low fiber control, and low fiber plus vitamin B12 treatments were 29.6, 3.59, 1192; 31.5, 2.85, 840; 28.0, 2.58, 715; and 28.8, 2.65, 760. Injections of vitamin B12 did not correct the milk fat depression associated with the low fiber diets. In addition, there was no consistent relationship between blood B12 and milk fat production. Milk fat production was highly correlated with molar percent acetate in the rumen .63 and with blood acetate concentration .74.
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PMID:Vitamin B12 administration for milk fat synthesis in lactating dairy cows fed a low fiber diet. 627 57

In a survey of 46 randomly selected diabetic patients on biguanide therapy, 30% had malabsorption of vitamin B12. Withdrawal of the drug resulted in normal absorption in only half of those with malabsorption. In most patients with persistent malabsorption, the results of absorption tests with exogenous intrinsic factor suggested the diagnosis of coincidental intrinsic factor deficiency. Further considerations, however, led to the concept that biguanides can induce malabsorption by two different mechanisms. One of these is temporary and unrelated to intrinsic factor secretion and the other is permanent and mediated by depression of intrinsic factor secretion.
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PMID:Malabsorption of vitamin B12 and intrinsic factor secretion during biguanide therapy. 682 78

Local cerebral glucose utilization (LCGU), as measured by the 2-deoxy-D-[1-14C]glucose technique, reflects local cerebral functional activity. In an effort to elucidate mechanisms of the encephalopathy associated with deficiency of vitamin B12, LCGU was determined in two recently described models of effective B12 deficiency: exposure of rats to subanesthetic doses of nitrous oxide (N2O) and/or administration of 1-amino-cyclopentane-1-carboxylic acid (cycloleucine). Our results show that exposure of adult rats to N2O depresses LCGU selectively in cortical, auditory, and limbic structures, in association with a depression in whole-brain activities of the vitamin B12-dependent methyltetrahydrofolate-homocysteine methyl-transferase (EC 2.1.1.13, methionine synthetase). Cycloleucine has no discernible effect on LCGU in the adult rat and does not change the cerebral activity of methionine synthetase.
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PMID:Local cerebral glucose utilization in two models of B12 deficiency. 683 46

We evaluated the association between nutritional status and cognitive functioning in 260 noninstitutionalized men and women older than 60 years who had no known physical illnesses and were receiving no medications. Nutritional status was evaluated by three-day food records and also by biochemical determination of blood levels of specific nutrients. Cognitive status was evaluated by the Halstead-Reitan Categories Test (a nonverbal test of abstract thinking ability) and by the Wechsler Memory Test. Subjects with low blood levels of vitamins C or B12 scored worse on both tests. Subjects with low levels of riboflavin or folic acid scored worse on the categories test. These differences remained significant after controlling for age, gender, level of income, and amount of education. "Subclinical" malnutrition may play a small role in the depression of cognitive function detectable in some elderly individuals, or depressed cognitive function may result in reduced nutrient intake.
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PMID:Association between nutritional status and cognitive functioning in a healthy elderly population. 684 5

Pregnant ewes were fed a depletion diet low in cobalt (0.06 ppm) for 3 1/2 months. Chronic catheters were implanted 8 weeks postpartum and 7 experiments were performed on these nonlactating vitamin B-12-depleted sheep (de-B12: 340 +/- 30 ng vitamin B-12 per gram wet liver) prior to repletion by intramuscular injection of hydroxocobalamin. Six experiments were then repeated after vitamin B-12 repletion (re-B12: 2220 +/- 50 ng vitamin B-12 per gram wet liver). The hepatic extraction ratios (HER) in continuously fed sheep were 0.81 and 0.77 for de-B12 and re-B12 corresponding to net hepatic uptakes of 460 +/- 50 and 440 +/- 40 mumol propionate per minute, respectively. Continuous infusion of unlabeled propionate into a mesenteric vein at 1 mmol/minute reduced the HER, yet this depression was greatest for re-B12 (0.74 vs. 0.63 for de-B12 and re-B12, respectively). Net hepatic uptake of propionate was increased (1145 +/- 100 vs. 985 +/- 95 mumol/minute, respectively), although vitamin B-12 status was without effect. It is concluded that the ability of liver to extract propionate is not affected at vitamin B-12 concentrations greater than 250 ng/g wet liver. However, when propionate entry rate was enhanced by intramesenteric infusion, the livers of de-B12 sheep had a greater capacity to remove propionate suggesting that alternate routes of metabolism may occur.
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PMID:Influence of vitamin B-12 status on hepatic propionic acid uptake in sheep. 685 14

Although an association of psychiatric symptoms with vitamin B12 deficiency is well accepted, the incidence and nature of these symptoms is not established. To help illuminate the natural history of this illness we review the literature regarding psychopathology associated with B12 deficiency and examine 15 cases, including one of our own, that meet specified criteria for B12-responsive psychosis. In the accepted cases the most common psychiatric symptoms were organic brain syndrome, paranoia, violence, and depression. Several of the patients were not anemic and had no neurologic deficit. Examination of blood smears or obtaining of serum B12 levels should be considered for patients with the symptoms described.
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PMID:B12 deficiency and psychiatric disorders: case report and literature review. 701 36

A 7-week-old infant with methylmalonic acidemia had pancytopenia and hypoplastic bone marrow. The patient responded to large doses of vitamin B12 treatment, and within 3 wk, the blood counts and bone marrow cellularity returned to normal. To understand the mechanism of marrow depression in this infant, we examined the effect of the patient's plasma and methylmalonic acid itself on the in vitro growth of bone marrow-committed stem cells. The patient's plasma obtained before B12 treatment completely inhibited the marrow cell growth, whereas the posttreatment plasma showed no inhibition. Methylmalonic acid when added to the culture dishes in concentrations comparable to those reported in plasma of methylmalonic acidemia patients, inhibited growth of marrow stem cells in a concentration-dependent fashion. On the other hand, 16 to 18 hr incubation of cells in the same concentration of methylmalonic acid did not affect the recovery of viability of the cells. The observations suggest that methylmalonic acid is inhibitory to the proliferation of marrow stem cells. The mechanism of inhibition is yet to be elucidated.
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PMID:Inhibition of bone marrow stem cell growth in vitro by methylmalonic acid: a mechanism for pancytopenia in a patient with methylmalonic acidemia. 725 44

The fat, protein and B12 absorption by the liver, kidney and small intestine was studied by radionuclide methods in gastric cancer patients during the preoperative period as well as within 15-30 days, 3-12 months and for more than a year following gastrectomy. It was observed that the function of the kidney, liver and B12 absorption was disturbed during the preoperative period. Gastrectomy caused a marked depression of the renal, hepatic and small intestinal function. During later periods following gastrectomy, these functions improved but were not restored to normal.
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PMID:[Radionuclide methods in evaluating the sequelae of gastrectomy for cancer]. 730 54

An outbreak of white liver disease in lambs in Western Australia is described. The disease affected 2- to 3-month-old lambs and was characterised by liver damage, severe ill-thrift, depression, serous ocular discharge, photosensitization, and a high mortality rate. Transient central nervous system signs occurred. A positive response to vitamin B12 therapy was demonstrated.
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PMID:White liver disease in lambs. 734 Jul 80

Three experiments were conducted with White Leghorn chicks hatched from hens fed diets varying in levels of protein, fat, and vitamin B12. Adding animal fat at a level of 10% in the chick diet caused growth depression of vitamin B12 deficient chicks, regardless of protein or energy level of hen or chick diet. Increasing the level of fat to 20% in the chick diet caused further growth depression and increased mortality. Feed efficiency of vitamin B12 deficient chicks was severely depressed by each additional increment in the fat level. Increasing protein content from 20 to 30% in the chick diet resulted in severe growth depression and poor feed efficiency. Although the added fat in the 30% protein chick diet depressed growth of chicks hatched from hens fed the 16 and 32% protein with added fat, it improved growth of those hatched from hens fed the similar diets with no added fat. Added fat in the 30% protein chick diet also improved feed efficiency of all chicks regardless of breeder diet treatments. Chicks hatched with an adequate carry-over of vitamin B12 from hens or chicks fed a diet with 10 micrograms of added vitamin B12/kg of feed did not show the growth depression caused by the high level of fat in the 20 and 30% protein chick diets. Feed efficiency was greatly improved by the addition of vitamin B12 to all chick diets. In a 22% protein vitamin B12 deficient diet, isocaloric substitution of glucose for fat depressed chick growth significantly and this growth depression was counteracted by supplementing the diet with 10 or 100 micrograms of vitamin B12/kg of feed. The vitamin B12 requirement was not increased by such substitution in the 22% protein diet. In contrast, isocaloric substitution of fat for glucose in the 32% protein chick diet increased the vitamin B12 need for optimum growth.
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PMID:The effect of vitamin B12 on the tolerance of chicks for high levels of dietary fat and carbohydrate. 746 1


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