Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The myelopathy associated with human immunodeficiency virus (HIV) infection closely resembles that in subacute combined degeneration, a disorder of vitamin B12 metabolism. To investigate whether the disorders share a pathogenetic mechanism, S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) were measured in the cerebrospinal fluid (CSF) of 20 HIV-seropositive patients and 30 HIV-negative patients who were undergoing lumbar puncture for other medical reasons. The HIV-seropositive patients had significantly lower CSF concentrations of SAM (mean 77 [SD 25] vs 131 [35] nmol/l; p less than 0.001) and significantly higher concentrations of SAH (30.5 [6.8] vs 19.0 [7.1] nmol/l; p less than 0.001) than the controls. There was therefore a significant difference between the groups in the SAM/SAH (methylation) ratio (HIV 2.7 [1.0] vs control 7.6 [3.4]; p less than 0.001). There were no correlations between SAM or SAH concentrations or methylation ratio and age or sex in both groups, or serum B12 and folate concentrations, CSF folate, serum or CSF methylmalonic acid, risk factors, body mass index, specific drug treatment received, or disease stage in the HIV group. This finding suggests that HIV affects the brain from a very early stage of the infection. We suggest that, as in the pig, the CSF methylation ratio closely reflects that in the brain. In HIV-infected patients a reduced brain methylation ratio would inhibit methyltransferase enzymes, which would lead to hypomethylation in the central nervous system and ultimately to neurological lesions. In a pig model of subacute combined degeneration and in vitamin-B12-deficient human beings, the primary cause of the low methylation ratio is impaired recycling of SAH back to SAM, a process which requires vitamin-B12-dependent methionine synthase. The HIV patients in this study were vitamin B12 and folate replete, which suggests a different cause for the low methylation ratio.
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PMID:Evidence of brain methyltransferase inhibition and early brain involvement in HIV-positive patients. 167 30

The aim of the present prospective study was to determine if malnutrition, measured using a simple validated score, is an independent risk factor for nosocomial infections (NI) in non-selected hospital in-patients. Between 29 and 31 May 2001, a survey on the prevalence of NI was conducted on all 1637 in-patients (61 (SD 25) years old) in a French university hospital as part of a national survey. Actual and usual body weights were recorded in all in-patients, and serum albumin levels were measured on all blood samples taken during the week before the study. Nutritional status was evaluated by using the nutritional risk index (NRI). Albumin values were obtained in 1084 patients, and complete weight information was obtained in 911. Therefore, NRI was calculated in 630 patients (61 (SD 20) years old): 427 (67.8 %) were malnourished. NI prevalence was 8.7 %: 4.4 % in non-malnourished patients, 7.6 % in moderately malnourished patients and 14.6 % in severely malnourished patients. In univariate analysis, the odds ratios for NI were 1.46 (95 % CI 1.2, 2.1) in moderately malnourished patients and 4.98 (95 % CI 4.6, 6.4) in severely malnourished patients. In multivariate analysis, age, immunodeficiency and NRI class influenced NI risk. Vascular and urinary catheters, and surgical intervention, were the extrinsic factors associated with NI, with odds ratios ranging from 2.0 (95 % CI 1.8, 2.6) for vascular catheters to 10.8 (95 % CI 8.8, 12.6) for association of the three factors. In conclusion, in non-selected hospitalized patients, malnutrition assessed with a simple and objective marker is an independent risk factor for NI. An early screening for malnutrition may therefore be helpful to reduce the high prevalence of NI.
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PMID:Malnutrition is an independent factor associated with nosocomial infections. 1523 Sep 93