Search results for "B12"
showing 10 items of 64 documents
Insights into the red algae and eukaryotic evolution from the genome of Porphyra umbilicalis (Bangiophyceae, Rhodophyta).
2017
Porphyra umbilicalis (laver) belongs to an ancient group of red algae (Bangiophyceae), is harvested for human food, and thrives in the harsh conditions of the upper intertidal zone. Here we present the 87.7-Mbp haploid Porphyra genome (65.8% G + C content, 13,125 gene loci) and elucidate traits that inform our understanding of the biology of red algae as one of the few multicellular eukaryotic lineages. Novel features of the Porphyra genome shared by other red algae relate to the cytoskeleton, calcium signaling, the cell cycle, and stress-Tolerance mechanisms including photoprotection. Cytoskeletal motor proteins in Porphyra are restricted to a small set of kinesins that appear to be the on…
Human Intrinsic Factor Expression for Bioavailable Vitamin B12 Enrichment in Microalgae
2018
Dietary supplements and functional foods are becoming increasingly popular complements to regular diets. A recurring ingredient is the essential cofactor vitamin B12(B12). Microalgae are making their way into the dietary supplement and functional food market but do not produce B12, and their B12 content is very variable. In this study, the suitability of using the human B12-binding protein intrinsic factor (IF) to enrich bioavailable B12 using microalgae was tested. The IF protein was successfully expressed from the nuclear genome of the model microalga Chlamydomonas reinhardtii and the addition of an N-terminal ARS2 signal peptide resulted in efficient IF secretion to the medium. Co-abunda…
Impact of supplementation with vitamins B 6 , B 12 , and/or folic acid on the reduction of homocysteine levels in patients with mild cognitive impair…
2021
Hyperhomocysteinemia is an independent predictor of the risk for cognitive decline and may be a result of low levels of vitamins B12 , B6 , and folate. Previous findings suggest that adequate intake of these vitamins may reduce homocysteine levels. This review aimed to assess the effects of treatment with vitamins B6, B12 , and/or folic acid in the homocysteine levels in patients with mild cognitive impairment (MCI). A systematic literature review was conducted in EMBASE, MEDLINE®, PsycINFO, and Cochrane Central Register of Controlled Trials. The research question was formulated using the Population, Intervention, Comparison, and Outcome (PICO) framework: in patients with MCI (P); what is t…
Exposure to Toxic Heavy Metals Can Influence Homocysteine Metabolism?
2019
Background: Homocysteine is a sulfur amino acid whose metabolism is activated in two pathways: remethylation to methionine, which requires folate and vitamin B12, and transsulfuration to cystathionine, which needs pyridoxal-5’-phosphate. High homocysteine level increases the risk of developing heart disease, stroke, peripheral vascular diseases, and cognitive impairment. Some evidence showed that exposure to these metals increased plasma homocysteine levels. Methods: A systematic review was carried out to clarify the relationship between homocysteine blood levels and exposure to toxic heavy metals (Lead, Cadmium, Mercury, and Chromium). Results: The results of this systematic review i…
Effects of marathon running on plasma total homocysteine concentrations.
2003
Summary Aims There is evidence of an excess of acute cardiovascular (CV) events in marathon runners. High plasma total homocysteine (tHcy) concentrations are a recognised risk factor for CV events. Therefore, we investigated the changes in plasma tHcy concentrations 24 h before and after a marathon race. Methods and results Twenty-two non-professional male athletes, mean age 35.6 (6.6), range 23–49 years, were studied the day before and 24 h after finishing a marathon race. None of the athletes was a carrier of the MTHFR 677TT genotype and no ingestion of supplements of vitamins (B12, B6, folic acid) was allowed. Results Changes in plasma folate and plasma vitamin B12 concentrations were no…
Vitamin B12 and hepatic enzyme serum levels correlate in male alcohol-dependent patients.
2001
- Vitamin B12 serum levels and markers for alcohol consumption were determined in 80 male alcohol-dependent patients. Spearman correlation coefficients (r(S)) were calculated. Significant positive correlations between vitamin B12 and hepatic enzyme values were found (gamma-glutamyltransferase: r(S) = 0.58; alanine aminotransferase: r(S) = 0.43; aspartate aminotransferase: r(S) = 0.47; glutamate dehydrogenase: r(S) = 0.43; all P:0.001). Therefore, for a proper interpretation of vitamin B12 levels, it may be clinically relevant to take markers of hepatocellular damage into account.
Higher vitamin B12 levels in neurodevelopmental disorders than in healthy controls and schizophrenia
2020
Recent studies suggest that both high and low levels of vitamin B12 (vitB12) may have negative health impacts. We measured VitB12 in patients with the Neurodevelopmental disorders (ND) (n = 222), comprised of Autism Spectrum Disorders, specific Developmental disorders, and Intellectual Disability (aged 2-53 years), schizophrenia (n = 401), and healthy controls (HC) (n = 483). Age-and gender-adjusted vitB12 z-scores were calculated by comparisons with a reference population (n = 76 148). We found higher vitB12 in ND (median 420 pmol/L, mean z-score: 0.30) than in HC (316 pmol/L, z-score: 0.06, P < .01) and schizophrenia (306 pmol/L, z-score: -0.02, P < .001), which was significant after adju…
Prevalence of methylenetetrahydrofolate reductase 677T and 1298C alleles and folate status: a comparative study in Mexican, West African, and Europea…
2006
Background: Methylenetetrahydrofolate reductase (MTHFR) 677C→T polymorphism is heterogeneously distributed worldwide, with the highest and lowest frequencies of the T allele in Mexico and Africa, respectively, and a south-to-north gradient in Europe. Distribution of MTHFR 1298A→C is less well known. It has been hypothesized that 677T frequency could result in part from gene-nutrient interactions. Objective: The objective was to compare the association of 677T and 1298C alleles with plasma concentrations of homocysteine, folate, and vitamin B-12 in geographical areas with contrasting 677T allele frequencies. Design: Healthy young adults (n = 1:277) were recruited in Mexico City, the West Afr…
Elevated plasma total homocysteine in centenarians
2004
Homocysteine (Hcy) is a sulfur-containing metabolite of methionine and is an emerging independent risk factor for atherosclerosis. Previous studies have shown that age, gender, renal function and folic acid intake are the main factors influencing total plasma Hcy levels in humans. A unique approach to the science of human longevity is the natural model of centenarians. The objective of this study was to verify whether the previously determined risk factors for atherosclerosis and atherosclerosis-related diseases change with age and, finally, to establish the vitamin nutritional status role. We studied 54 centenarians (14 males and 40 females) aged between 100-107 years (mean age 102.6+/-1.8…
Long-term metabolic effects in patients with urinary diversion
1998
The use of intestinal segments in genitourinary reconstruction could influence vitamin metabolism and affect the skeletal bone and its mineral content in the long term. In 137 patients, serum levels of the vitamins A, B1, B2, B6, B12, D, and E and of folic acid, bile acid, and ammonia as well as levels of intracorpuscular vitamin B12 and folic acid were examined and a red blood cell count was performed. The patients were divided into three groups (or = 2 years,2 toor = 4 years, and4 years after surgery) as well as into children and adults. In addition, bone mineral density (dual-photon absorptiometry) was measured in 25 patients. Of these, 16 patients were approximately 16.8 years s/p recta…