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

Neurologic manifestations of vitamin B12 deficiency are protean, including neuropathy, depression, and dementia. We present evidence to dispel confounding myths about vitamin B12 deficiency. Hematologic indices are normal in up to 30% of patients with vitamin B12 deficiency, and results of the Schilling test may be normal in patients with symptoms of deficiency. Isolated neuropathy or myelopathy may occur independently, but often appear concurrently. The neuropathy is primarily axonal and predominantly sensory. Myelopathy is caused by demyelinated areas in posterior and lateral columns. After therapy, recovery from neuropathy is incomplete or may extend for several years. Vitamin B12 replacement should not be withheld from patients with borderline vitamin B12 levels, since the consequences of allowing myelopathy, neuropathy, dementia, and mental disorders to worsen clearly outweigh any disadvantage of therapy.
 ...
PMID:Myths about vitamin B12 deficiency. 174 82

Recent adoption by the American Conference of Governmental Industrial Hygienists of a Threshold Limit Value of 50 ppm for an 8-hour average exposure to nitrous oxide (N2O) increases the likelihood for its regulation by state and federal occupational health agencies. This review outlines current information on the health risks of N2O inhalation to provide a basis from which safe and reasonably attainable exposure limits can be proposed. Although N2O was for many years believed to have no toxicity other than that associated with its anesthetic action, bone marrow depression in patients administered N2O for extended periods of time and neurological abnormalities in health care workers who inhaled N2O recreationally have disproved this notion. Retrospective surveys of dental and medical personnel have also linked occupational exposure to N2O with a number of health problems and reproductive derangements. Nitrous oxide reacts with the reduced form of vitamin B12, thereby inhibiting the action of methionine synthase, an enzyme that indirectly supports methylation reactions and nucleic acid synthesis. Many, if not all, of the nonanesthetic-related adverse effects of N2O may be ascribed to this action. Animal and human studies indicate that the toxic effects of N2O are concentration- and time-dependent. It is suggested that a time-weighted average of 100 ppm for an 8-hour workday and/or a time-weighted average of 400 ppm per anesthetic administration would provide adequate protection of dental personnel and be achievable with existing pollution control methods.
 ...
PMID:Health hazards and nitrous oxide: a time for reappraisal. 180 46

This study compared the B complex vitamin status at time of admission of 20 geriatric and 16 young adult non-alcoholic inpatients with major depression. Twenty-eight percent of all subjects were deficient in B2 (riboflavin), B6 (pyridoxine), and/or B12 (cobalamin), but none in B1 (thiamine) or folate. The geriatric sample had significantly higher serum folate levels. Psychotic depressives had lower B12 than did non-psychotic depressives. Poorer blood vitamin status was not associated with higher scores on the Hamilton Depression Rating Scale or lower scores on the Mini-Mental State Examination in either age group. The data support the hypothesis that poorer status in certain B vitamins is present in major depression, but blood measures may not reflect central nervous system vitamin function or severity of affective syndromes as measured by the assays and scales in the present study.
 ...
PMID:B complex vitamin patterns in geriatric and young adult inpatients with major depression. 200 38

This retrospective study evaluated the relationships between normal serum vitamin B12 and folate levels and neuropsychologic measures in a sample of 60 geriatric inpatients with psychotic depression, nonpsychotic depression, bipolar disorder, and dementia--all consecutively referred for cognitive testing. The psychotic depression subgroup demonstrated numerous significant positive correlations between B12 and cognitive subtests not seen in other diagnostic subgroups, especially those of IQ, and verbal and visual memory. Metabolic factors including vitamin B12 may play specific roles in the cognitive dysfunctions of different geropsychiatric disorders.
 ...
PMID:Relationship of normal serum vitamin B12 and folate levels to cognitive test performance in subtypes of geriatric major depression. 220 65

Dementia is a syndrome of acquired intellectual deterioration that interferes with personal or social functioning. Diagnosis requires historical information from the family and the mental status evaluation of orientation, recent memory, comprehension, calculation, and abstraction. Most dementias create permanent, even progressive cognitive deterioration, yet there are some presentations for which remission exists. Common reversible conditions include depression, drug toxicity, normal-pressure hydrocephalus, hypothyroidism, subdural hematoma, and neoplasm. Screening laboratory studies consist of urinalysis, chemistry profile, blood count, thyroid survey, vitamin B12 and folate measurements, serology, chest roentgenogram, computerized tomographic scan of the head, electroencephalogram, and electrocardiogram. Treatment focuses on potential reversibility, psychosocial issues, restoring deficits, and specific symptoms.
 ...
PMID:Dementia: what to do. 221 59

In AIDS, as previously found in pernicious anemia (PA), the earliest serum marker of subnormal vitamin B12 (cobalamin) absorption, and therefore of negative B12 balance, is low serum holotranscobalamin II (holo-TC II; B12-TC II) despite normal total serum B12 level, normal serum homocysteine, and normal classic (oral free radio-B12) Schilling test. This may be accompanied by subtle and insidious damage to hematopoietic, immunologic, neuropsychiatric, nutritional and alimentary systems, confirmed by correction on therapeutic trial with B12 therapy. Our studies suggest such selective B12 deficiency occurs in about half of the HIV-1 infected, in part due to frequent depression of B12 absorption by HIV-1 attack on the gastric mucosa and/or opportunistic infection attack on the small bowel, and in part due to a telescoping of the continuum of the stages of negative B12 balance in relation to damage to B12 delivery by the infective and/or systemic disease process. In AIDS, when total serum B12 is normal despite tissue depletion of B12, if the classic Schilling test does not reveal subnormal food B12 absorption, the food Schilling test does. We hypothesize that DNA-synthesizing cells of the hematopoietic, immunologic, neurologic and other systems which have surface receptors solely for holo-TC II, and which have low B12 stores, rapidly become dysfunctional due to B12 deficiency when holo-TC II is low, while cells (such as liver cells) which also have surface receptors for holohaptocorrin (B12-haptocorrin) remain B12-replete. We believe this to be another example of the concept of selective nutrient deficiency in one cell line but not another.
 ...
PMID:Low holotranscobalamin II is the earliest serum marker for subnormal vitamin B12 (cobalamin) absorption in patients with AIDS. 233 79

The effect of vitamin B12 (B12) deficiency on the levels of S-adenosylmethionine (SAM) in tissues and the activities of hepatic methionine synthase, methionine adenosyltransferase and glycine N-methyltransferase were investigated. The striking depression of methionine synthase activity was observed in all rats fed the B12-deficient diets with or without methionine supplementation for 150 days. The SAM level in liver was decreased by B12 deficiency. However, brain SAM level was not affected. The activities of hepatic methionine adenosyltransferase isozymes, alpha-form and beta-form, were decreased by B12 deficiency. Hepatic glycine N-methyltransferase activity in rats fed the low methionine-B12-deficient diet showed a tendency to lower, although the change the activity was not statistically significant, compared with B12-supplemented rats. It is proposed that the fall in the activity of hepatic methionine adenosyltransferase may be one of the causes of the decreased hepatic SAM level in B12-deficient rats.
 ...
PMID:Effect of vitamin B12 deficiency on S-adenosylmethionine metabolism in rats. 273 12

We studied the effect of vitamin B complex (vitamin B1, B6 and B12 complex) on the immune responsiveness in gastric cancer patients who underwent surgery. The depression of blastogenic responses to both PHA and PWM was observed 2 weeks after surgery in half of the patients treated with Vitamedin but the degree was significantly less than that in the control patients without vitamin B treatment whose lymphocyte responses were depressed. Moreover, the blastogenic responses were induced by vitamin B administration 2 or 4 weeks after surgery in 5 of the 8 stage III-IV patients whose lymphocytes had not responded prior to surgery. Four weeks after surgery, the patients without vitamin B treatment showed only a tendency of recovery of their lymphocyte responses, whereas the recovery of blastogenic responses in the patients treated with vitamin B was significant. Essentially similar results were obtained with skin reactions to PHA and PPD. These results suggest that the administration of vitamin B1, B6 and B12 complex is useful for the protection against and the recovery of immune dysfunction produced by surgery in cancer patients.
 ...
PMID:Effect of vitamin B complex on the immunodeficiency produced by surgery of gastric cancer patients. 321 Mar 44

To explore the role of vitamin B in neural mechanisms of analgesia, we investigated the effect of a compound of vitamins B1, B6 and B12 (Neurobion, E. Merck) on the nociceptive responses of single neurons in the spinal cord dorsal horn in anesthetized cats. Intrathecal superfusion of Neurobion, using a small pool placed on the spinal surface, produced a significant dose-dependent depression in the responses evoked by noxious skin heating (50 or 52 degrees C, 10 s) of hindfoot skin, but not of spontaneous activity in dorsal horn neurons. These results indicate that the therapeutic effect of vitamin B compounds in the clinical management of pain may involve a suppression of nociceptive transmission at the spinal level.
 ...
PMID:B vitamins suppress spinal dorsal horn nociceptive neurons in the cat. 322 8

Serum iron, folate, B12 and total iron binding capacity (TIBC) were obtained preoperatively and at 6-month intervals in 40 morbidly obese patients who underwent VGB. Deficiencies of hemic micronutrients rarely occurred following VBG. Hemoglobin and hematocrit levels were within normal limits at all times. Some patients experienced transitory depression of nutrients at six months postoperatively, during the period of most rapid weight loss and lowest dietary intake. These levels return to normal by one year in almost all cases. Low B12 levels were observed in four patients at 1 year. All had been above 120 per cent overweight and had lost in excess of 100 pounds in the first postoperative year. These data indicate that hemic micronutrients remain at normal levels following VBG. B12 levels should be followed to determine possible need for supplementation other than that provided by usual daily multivitamin preparations in patients above 120 per cent ideal weight loss exceeding 100 lbs in the first postoperative year.
 ...
PMID:Hemic micronutrients following vertical banded gastroplasty. 336 61


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>