vitamin-b-12 and Bacterial-Infections

Antivitamins represent a broad class of compounds that counteract the essential effects of vitamins. The symptoms triggered by such antinutritional factors resemble those of vitamin deficiencies, but can be successfully reversed by treating patients with the intact vitamin. Despite being undesirable for healthy organisms, the toxicities of these compounds present considerable interest for biological and medicinal purposes. Indeed, antivitamins played fundamental roles in the development of pioneering antibiotic and antiproliferative drugs, such as prontosil and aminopterin. Their development and optimisation were made possible by the study, throughout the 20th century, of the vitamins' and antivitamins' functions in metabolic processes. However, even with this thorough knowledge, commercialised antivitamin-based drugs are still nowadays limited to antagonists of vitamins B9 and K. The antivitamin field thus still needs to be explored more intensely, in view of the outstanding therapeutic success exhibited by several antivitamin-based medicines. Here we summarise historical achievements and discuss critically recent developments, opportunities and potential limitations of the antivitamin approach, with a special focus on antivitamins K, B9 and B12 .

Topics: 4-Hydroxycoumarins; Animals; Anti-Bacterial Agents; Anticoagulants; Antineoplastic Agents; Bacteria; Bacterial Infections; Drug Discovery; Folic Acid; Folic Acid Antagonists; Humans; Indenes; Models, Molecular; Neoplasms; Vitamin B 12; Vitamin K; Vitamins

Topics: Bacterial Infections; Bile Acids and Salts; Carbohydrates; Diarrhea; Humans; Intestinal Absorption; Intestinal Diseases; Intestine, Small; Lipid Metabolism; Proteins; Vitamin B 12; Vitamin B 12 Deficiency

Contamination of the small bowel with an abnormal microflora causes a variety of disturbances of intraluminal digestion and of mucosal function resulting in malabsorption of fat, protein, carbohydrate, electrolytes and vitamin B12. Indirect clinical tests for the presence of small bowel bacterial overgrowth must be supported by careful roentgenologic examination of the small intestine and intestinal aspiration studies to establish a firm pretreatment diagnosis. However, the reversal of absorptive defects by antibacterial therapy is valuable confirmatory evidence.

Topics: Anti-Bacterial Agents; Bacterial Infections; Breath Tests; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Humans; Intestinal Absorption; Intestine, Small; Malabsorption Syndromes; Vitamin B 12; Water-Electrolyte Balance

Topics: Animals; Bacteria; Bacterial Infections; Carbohydrate Metabolism; Celiac Disease; Digestive System; Fatty Acids; Fatty Alcohols; Humans; Intestine, Small; Malabsorption Syndromes; Nutrition Disorders; Nutritional Physiological Phenomena; Protein Deficiency; Protein-Losing Enteropathies; Proteins; Rats; Symbiosis; Vitamin B 12; Vitamin B 12 Deficiency

The role of bacteria in the bioavailability of protein-bound vitamin B12 was examined in eight elderly subjects who had atrophic gastritis and in eight normal controls. On separate days and in random order, vitamin B12 absorption tests were performed using either radiolabeled crystalline or protein-bound vitamin B12. At the same time, bacterial samples were collected from the upper gastrointestinal tract. The tests and gastrointestinal aspirates were performed before and during tetracycline therapy. Crystalline vitamin B12 was absorbed to the same extent in the two study groups. Atrophic gastritis subjects absorbed significantly less protein-bound vitamin B12 than normal controls (mean +/- SEM, 0.7% +/- 0.2% vs. 1.9% +/- 0.5%, respectively). However, protein-bound vitamin B12 absorption in these subjects normalized after antibiotic therapy. These results suggest that the small amounts of vitamin B12 released from the protein binders is readily absorbed (as shown in vitro) and/or metabolized by bacteria.

Topics: Achlorhydria; Aged; Bacterial Infections; Biological Availability; Female; Gastritis, Atrophic; Humans; Intestinal Absorption; Male; Tetracycline; Transcobalamins; Vitamin B 12; Vitamin B 12 Deficiency

Biomarkers of oxidative stress (OS) have been poorly explored in fungal peritonitis (FP). Potassium is a regulator of pro-oxidants and antioxidants. Albumin and vitamin B. Serum levels of potassium, albumin and B. These findings suggest lower serum potassium, albumin and B

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Antifungal Agents; Bacterial Infections; Biomarkers; Female; Humans; Male; Middle Aged; Mycoses; Oxidative Stress; Peritonitis; Potassium; Retrospective Studies; Risk Factors; Serum Albumin; Treatment Outcome; Vitamin B 12

Vitamin B

Topics: Animals; Bacteria; Bacterial Infections; Biological Transport; Caenorhabditis elegans; Corrinoids; Fluorescent Dyes; Humans; Lepidium sativum; Microscopy, Fluorescence; Models, Molecular; Mycobacterium tuberculosis; Vitamin B 12

The influence of luminal bacteria on small-intestinal permeability has not been fully assessed. This study addressed this issue.. Thirty-four subjects (mean age 64 years; range 22-95 years) were investigated for possible small-intestinal bacterial overgrowth (SIBO) with culture of a small-intestinal aspirate. A lactulose/mannitol small-intestinal permeability test was performed, small-intestinal histology assessed and serum vitamin B12 concentrations measured in all subjects. Permeability was also assessed in a control group of 34 asymptomatic volunteers.. Urinary lactulose/mannitol ratios were significantly increased in subjects with SIBO with colonic-type flora (P < 0.0005), even in the absence of villous atrophy. Urinary lactulose/mannitol ratios were increased in this group due to significantly increased urinary lactulose concentrations (P < 0.0005) rather than reduced urinary mannitol levels, after correcting for inter-subject variations in renal function. Counts of intraepithelial lymphocytes of CD8 phenotype were significantly increased in this group (P = 0.003). Although a significant correlation was found between intraepithelial lymphocyte counts and small-intestinal permeability overall (P < 0.002), these counts were not significantly different in subjects with SIBO with colonic-type flora whose permeability values were < or = > 0.028, the upper limit of normal in asymptomatic controls. Serum vitamin B12 concentrations did not differ significantly between groups (P > 0.5). Ageing did not independently influence small-intestinal permeability (P > 0.5).. Small-intestinal permeability is increased in subjects with SIBO with colonic-type bacteria. This effect is independent of ageing and not mediated by vitamin B12 deficiency. Although counts of intraepithelial lymphocytes of CD8 phenotype are increased in this disorder, it is also unlikely that these cells play an important causative role in this process. Routine light microscopic assessment underestimates the prevalence of small-intestinal functional disturbance in this disorder.

Topics: Bacterial Infections; Case-Control Studies; Humans; Intestinal Absorption; Intestinal Secretions; Intestine, Small; Lactulose; Mannitol; Middle Aged; Permeability; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Aged; Bacterial Infections; Dietary Fats; Diverticulitis; Female; Folic Acid; Humans; Jejunal Diseases; Malabsorption Syndromes; Serum Albumin; Vitamin B 12

It is recognised that prolonged anaesthesia with nitrous oxide (N2O) induces megaloblastic anaemia by oxidising vitamin B12. To determine whether sepsis aggravates the effect of N2O on haemopoiesis 5 patients with severe sepsis, who required surgery and were exposed to short-term (45-105 minutes) N2O anaesthesia, were studied. None had evidence of pre-operative vitamin B12 or folate deficiency. The effect of the combination of N2O anaesthesia and sepsis on DNA synthesis in bone marrow cells was assessed morphologically, and by the deoxyuridine suppression test. In 3 patients exposed to the longest duration (75-105 minutes) of N2O, addition of folinic acid and vitamin B12 partially improved the utilisation of deoxyuridine in vitro. No patient had evidence of megaloblastic haemopoiesis as judged by bone marrow morphology. It is concluded that prolonged N2O anaesthesia in patients with severe sepsis may adversely affect DNA synthesis. Although this effect did not manifest as overt megaloblastic erythropoiesis, it may be prudent to avoid N2O in such patients.

Topics: Adolescent; Adult; Bacterial Infections; Bone Marrow; Female; Folic Acid; Humans; Male; Nitrous Oxide; Time Factors; Vitamin B 12

Topics: Actinomycetales Infections; Amino Acids; Bacterial Infections; Bacteroides Infections; Bifidobacterium; Bile Acids and Salts; Clostridium Infections; Diarrhea; Enterobacteriaceae Infections; Folic Acid; Humans; Indican; Intestinal Absorption; Intestinal Diseases; Intestinal Mucosa; Intestine, Small; Lactobacillaceae; Malabsorption Syndromes; Monosaccharides; Protein-Energy Malnutrition; Veillonella; Vitamin B 12

Topics: Bacterial Infections; Creatinine; Equipment and Supplies, Hospital; Fever; Formaldehyde; Humans; Inulin; Isoantibodies; Molecular Weight; Phosphates; Renal Dialysis; Time Factors; Vitamin B 12

Topics: Bacteria; Bacterial Infections; Cobamides; Humans; Intestinal Diseases; Intestines; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Anemia; Bacterial Infections; Humans; India; Intestine, Small; Puerto Rico; Sprue, Tropical; Vitamin B 12

Since trimethoprim-sulfamethoxazole (TMP-SMX) was first marked occasional reviews have surveyed the pattern of adverse reactions. Skin rashes characteristic of sulfonamide sensitivity have predominated, with relatively few of a serious exfoliative nature. Hematologic adverse reactions recorded follow the pattern known to occur with sulfonamides, with a few cases related to the action of trimethoprim on human folate metabolism. Such an effect is more likely to occur when the patient's folate status is already jeopardized; it is rare in relation to the widespread use of the drug combination. Long-term administration does not per se seem to represent an additional hazard provided the dose is the correct one and the hematologic monitoring of the patient is performed regularly. The suggestion that TMP-SMX has a toxic effect on the kidney has not been substantiated. An estimated 250 million "standard treatment courses" have been given in the first 6 years of marketing and, overall, the picture of adverse reactions corresponds with that expected from a sulfonamide of relatively low toxicity.

Topics: Adult; Aged; Bacterial Infections; Blood Cell Count; Blood Cells; Blood Platelets; Child; Drug Combinations; Drug Eruptions; Drug Evaluation; Erythrocytes; Female; Folic Acid; Folic Acid Deficiency; Gastrointestinal Diseases; Hematologic Diseases; Hemoglobins; Humans; Long-Term Care; Male; Middle Aged; Sulfamethoxazole; Trimethoprim; Vitamin B 12

Topics: Bacterial Infections; Corrinoids; Diphtheria; Guinea Pigs; Sepsis; Toxemia; Vitamin B 12

Topics: Bacterial Infections; Corrinoids; Diphtheria; Sepsis; Toxemia; Vitamin B 12