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The effect of para-aminobenzoic acid and taurocholic acid feeding on human bile composition.

Seven patients were investigated after cholecystectomy and exploration of the common bile duct to determine bile composition and excretion rates. An initial depression of the major components of bile stabilized by the sixth postoperative day. Feeding of para-aminobenzoic acid and taurocholic acid to these patients demonstrated an increase in excretion of total bile acids, taurine and glycine conjugates, cholates and deoxycholates. Para-aminobenzoic acid in the doses used failed to block glycine conjugation. Preferential conjugation of bile acid with glycine is due to a deficient taurine pool and not a preferential metabolic pathway.

4-Aminobenzoic Acid

Effects of potassium para-aminobenzoate on growth and macromolecule synthesis in fibroblasts cultured from normal and sclerodermatous human skin, and rheumatoid synovial cells.

Potassium para-aminobenzoate was tested for its ability to affect growth and macromolecule synthesis in vitro using fibroblasts from normal human skin, from affected skin of patients with scleroderma, and rheumatoid synovial cells. The proliferation of all 3 cell types showed dose-dependent inhibition beginning at about 3000 microgram/ml. Acid mucopolysaccharide secretion by rheumatoid synovial cells and scleroderma fibroblasts was inhibited even at 100 microgram/ml, which is within the therapeutic range, and there was over 50% inhibition at 5000 microgram/ml. Collagen synthesis by several different strains, was not affected, despite the use of a range of concentrations and treatment times.

4-Aminobenzoic Acid

Nutritionally defined conditions for germination of Streptomyces viridochromogenes spores.

Spores of Streptomyces viridochromogenes were removed from the surface of solid media with glass beads and suspended in a buffer-detergent solution. Addition of yeast extract and glucose resulted in rapid loss of refractility of the spores. Appearance of germ tubes followed. Germination was accompanied by a decrease in the optical density (OD) of the suspension. The OD decrease was used as an assay for germination. A defined germination medium (DGM) comprised of L-alanine, L-glutamic acid, adenosine, para-aminobenzoic acid, and calcium and magnesium ions provided a germination rate nearly equal to that of complex media. The germination rate was essentially the same if D-alanine and D-glutamate replaced the L-isomers. The optimum pH and temperature for germination were 7.0 and 35 C. Germination was absolutely dependent on the presence of CO2. Spores harvested after growth for longer periods than the usual time (10 days) became less germinable in DGM. The same was observed for spores grown at 37 C as compared with 30 C. Spores incubated in DGM for various time periods before being transferred to a buffer solution did not continue to germinate. Spores harvested after growth of eight species of Streptomyces did not show a decrease in OD when incubated in yeast extract medium. Another strain of S. viridochromogenes did exhibit an OD decrease in the medium. Comparative properties of spores of streptomycetes, fungi, and bacilli are discussed.

Adenosine

Isolation of folate-producing probiotic candidates and their effects on homocysteine metabolism and gut microbiota composition.

BACKGROUND: Folate deficiency is a global nutritional problem associated with multiple adverse health outcomes, including impaired one-carbon metabolism and elevated homocysteine levels (hyperhomocysteinemia). Gut microbiota-mediated folate biosynthesis has emerged as a promising strategy for improving the host's folate status. This study aimed to isolate folate-producing probiotic strains, clarify their folate synthesis mechanisms, and evaluate their regulatory effects on folate metabolism and gut microbiota. METHODS: High-throughput cultivation and screening were performed to isolate folate-producing candidate probiotics. Whole-genome sequencing analysis, pathway reconstruction, and metabolite profiling in fermented milk were performed to explore folate biosynthesis pathways and microbial cross-feeding interactions. A folate-deficient mouse model was established to evaluate the effects of a candidate probiotic cocktail on serum folate, homocysteine (Hcy) levels, and gut microbiota composition using quantitative PCR (qPCR) and 16S rRNA gene sequencing. RESULTS: High-throughput screening identified 8 high-folate-producing candidate probiotic strains, including Lactiplantibacillus plantarum and Heyndrickxia coagulans, from over 1,000 isolates. Genomic analysis revealed that most commonly used probiotics lacked para-aminobenzoic acid (pABA) biosynthesis genes but retained downstream modules, suggesting a reliance on cross-feeding with pABA-producing gut commensals such as Bacteroides. Metabolite profiling of fermented milk demonstrated that selected strains significantly increased bioactive 5-methyltetrahydrofolate (5-MeTHF) and tetrahydrofolate levels. In vivo, only a high-dose candidate probiotic cocktail significantly elevated serum folate (p&#x202f;<&#x202f;0.05) and reduced homocysteine levels (p&#x202f;<&#x202f;0.05) in deficient mice. Fecal qPCR confirmed dose-dependent transient persistence of the administered bacterial species. Consistent with the qPCR data, 16S rRNA gene sequences demonstrated significant enrichment of these administered species observed in the high-dose group. Furthermore, beta-diversity analysis found that high-dose candidate probiotic supplementation promoted a shift in the gut microbiota composition toward a normal profile, partially mitigating the dysbiosis induced by the folate-deficient diet. This effect was accompanied by a significant enrichment of potential short-chain fatty acid producers (e.g., Lachnospiraceae and Oscillospiraceae) and the depletion of potential opportunistic pathogens. CONCLUSION: This study screened high-folate-producing candidate probiotic strains and demonstrated their ability to synthesize the active form of 5-MeTHF. Moreover, folate-producing candidate probiotic cocktail treatment significantly improved folate status and Hcy metabolism and modulated the gut microbiota by enriching potential beneficial bacterial taxa. These findings suggested that folate-producing probiotics may serve as a promising microbiota-based strategy to improve folate availability and homocysteine metabolism.

B vitamin

Cross immunological reactions between three haptens of the "para" group and 4-aminoantipyrine.

Cross passive hemagglutination reactions between sulfanilic acid (SA), para-aminobenzoic acid (PABA), p-phenethidine (PT) and 4-aminoantipyrine (4-AA) haptens have been investigated using conjugates of diazo derivaties of these compounds with homologous serum proteins. Intense cross passive hemagglutination reactions were found between PABA, SA and 4-AA haptens. Although anti-PT sera cross reacted intensely with PABA, SA as well as with 4-AA haptens, antibodies cross reacting with PT were not detected in any of the anti-PABA, anti-SA and anti-4-AA antisera. The conjugates containing a heterologous hapten de not substantially alter the titer of the hemagglutination reactions performed with erythrocytes coated with the homologous hapten, but completely suppress the hemagglutination reactions performed with erythrocytes coated with this hapten as well as with other, but not all, heterologous, haptens. The results support the conclusion that the apparent polysensitization to drugs may actually rely upon cross reactions with haptens chemically related to the immunizing one.

4-Aminobenzoic Acid

Convective diffusional analysis for drug transport through a tubular polymeric membrane.

The transport of three p-aminobenzoate esters (ethyl, butyl, and hexyl) through a tubular dimethyl polysiloxane membrane into a flowing liquid was investigated. The tubular configuration permits the exact determination of the convective diffusional contribution to membrane transport with models that account for fluid hydrodynamics. The observed transport behavior ranged from complete convective diffusion control for the hexyl ester to complete membrane control for the ethyl ester; the butyl ester exhibited a change in control with flow rate. The implications of convective diffusional considerations to intestinal absorption and dissolution studies are discussed.

4-Aminobenzoic Acid

Chymotrypsinlike activity of some intestinal bacteria.

Some tests of exocrine pancreatic function are based on the estimation of intestinal chymotryptic activity by using specific substrates such as N-benzoyl-L-tyrosyl-PABA (BT-P). In this study the action of a number of bacteria isolated from human or monkey intestines on BT-P was investigated. The monkeys studied had an intestinal flora closely resembling that of man. Except for Bacteroides, Proteus vulgaris No. 73, Proteus morgani No. 202, and Pseudomonas aeruginosa No. 76, significant splitting of BT-P did not take place when the common enteric microorganisms were tested. It was concluded that with the possible exception of bacterial overgrowth of the small bowel, microbial chymotryptic activity is not of importance.

4-Aminobenzoic Acid

The use of gamma-glutamyl-p-aminobenzoic acid as the substrate for determination of gamma-glutamyltranspeptidase activity in blood serum.

By the phthaloyl method less toxic and readily soluble gamma-L-glutamyl-p-aminobenzoic acid was synthesized. This substance was used as a substrate for gamma-glutamyltranspeptidase activity assay in blood serum and urine. Close correlation was shown between the results obtained with the new method and with the old one which used gamma-L-glutamyl-p-nitroanilide.

4-Aminobenzoic Acid

Effect of intestinal gamma-glutamyl transferase inhibitor on the amount of gamma-glutamyl metabolites in mouse.

Experimental mice fed a balanced rodent chow, called LSM fodder, had markedly lower gamma-glutamyl transferase activity in the epithelium of intestinal villi then control mice fed wheat. After oral administration of gamma-14C-glutamyglycine, oxidized 14C-glutathione or gamma-glutamyl-p-amino-benzoate the amounts of gamma-glutamyl substrates and their metabolites in intestines, livers and kidneys of experimental mice were significantly lower than those in control mice. L-serine simultaneously administered with gamma-14C-glutamylglycine reduced the radioactivity of gamma-glutamyl substances in organs of the control mice. No differences in organ radioactivity of experimental and control mice were observed when some uniformly labeled with 14C amino acids were given. The obtained results are not in aggreement with hypothesis on a role of gamma-glutamyl transferase in amino acid transport.

4-Aminobenzoic Acid

[Study of the histaminergic mechanisms of the action of malaben].

In rabbits (intact and with experimental myocardial infarction) histamine metabolism (histamine content and diaminoxidase activity) following introduction of malaben was studied. In intact animals the ability of malaben to reduce the blood histamine level and to activate diaminoxidase was discovered. Administration of malaben in experimental myocardial infarction promotes a quicker normalization of the disturbed metabolism of histamine.

4-Aminobenzoic Acid