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PubMed1963

POLYSACCHARIDE STORAGE AND GROWTH EFFICIENCY IN RUMINOCOCCUS ALBUS.

Hungate, R. E. (University of California, Davis). Polysaccharide storage and growth efficiency in Ruminococcus albus. J. Bacteriol. 86:848-854. 1963.-Ruminococcus albus strain RAM requires biotin, p-aminobenzoic acid, pyridoxamine, isovalerate, isobutyrate, 2-methylbutyrate, and either cysteine or sulfide. Rumen fluid and casein hydrolysate improve growth but are not essential. Up to 35% iodophilic polysaccharide is stored in cells from batch cultures and 17% in a continuous culture on a 10-hr cycle. The storage product is a polymer of glucose resembling starch. The yield of cells in continuous culture, corrected for stored starch, averaged 102 mg per mmole of cellobiose fermented to waste products. It is postulated that nine high-energy phosphates are derived from each cellobiose molecule. Conversions providing this number are discussed.

4-Aminobenzoic Acid↗
PubMed1997

In vitro human skin barrier modulation by fatty acids: skin permeation and thermal analysis studies.

PURPOSE: This study aims to elucidate the skin permeation enhancement and the skin perturbation effects of a number of fatty acids, i.e. straight-chain saturated (SFA), monounsaturated (MUFA) and polyunsaturated acids (PUFA). METHODS: The skin permeation enhancement effects were studied using human stratum comeum (SC) and p-aminobenzoic acid (PABA) as a model permeant. The fatty acids in propylene glycol (FA/PG) were applied according to a pre-treatment/co-treatment protocol. The perturbation effects were studied using differential thermal analysis (DTA) on SC after pretreatment with FA/PG. RESULTS: SFA with 6 to 12 carbons exhibit a parabolic correlation between enhancement effect and chain-length, with a maximum at nonanoic-decanoic acids (with 9 and 10 carbons). Nonanoic and decanoic acids exert barely noticeable effects on the thermal behaviour of SC, suggesting that they easily mix with the skin lipids. All cis-6-, 9-, 11- or 13-octadecenoic acids (MUFA) enhance the permeation of PABA to the same extent. DTA revealed that the cis-9- and 13-isomers form a separate domain containing mostly the pure fatty acids within the SC lipids and suppress the lipid transitions at 70 degrees/80 degrees C. PUFA--linoleic (LA), alpha-linolenic (ALA) and arachidonic acids--enhance PABA permeation stronger than MUFA but additional double bonds do not further increase the degree of enhancement. LA and ALA form separate domains but do not completely suppress the SC lipid transitions at 70 degrees/80 degrees C. Increase in the enthalpy changes of 70 degrees/80 degrees transitions linearly correlates to the decrease in the permeability coefficients, suggesting that an increased perturbation of the skin lipids not necessarily has to yield an increased PABA permeation. CONCLUSIONS: The enhancement effects of fatty acids on the PABA penetration through SC are structure-dependent, associated with the existence of a balance between the permeability of pure fatty acids across SC and the interaction of the acids to skin lipids.

4-Aminobenzoic Acid↗
PubMed1981

Specificity of the BT-PABA test for the diagnosis of exocrine pancreatic insufficiency in the dog.

Exocrine pancreatic insufficiency in the dog has been assessed by the oral administration of the synthetic peptide N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA), a specific substrate for pancreatic chymotrypsin. The subsequent assay of PABA in either the plasma or the urine clearly differentiated control animals from those with exocrine pancreatic insufficiency (EPI), the results being unaffected by combination of this pancreatic function with a xylose absorption test. Possible interference with the specificity of the peptide test for the diagnosis of EPI was examined in six animals with small intestinal disease. In a group of four animals, with features resembling chronic tropical sprue in man, the results were comparable to those of the control group. In the fifth case, however, the results were indistinguishable from those of the EPI group, the estimation of sodium PABA absorption and the assay of proteolytic activity in the duodenal juice demonstrating that this was due to defective hydrolysis of the peptide. In the sixth case, diffuse intestinal lymphosarcoma and a marked villous atrophy were associated with an apparent reduction in the absorption of sodium PABA. However, although the plasma PABA concentrations following oral BT-PABA were subnormal, they were distinctly higher than those of the EPI group. These findings suggest that small intestinal abnormalities do not affect PABA absorption sufficiently to interfere with the specificity of the peptide test for the detection of severe EPI in the dog. This insufficiency may occasionally be secondary to small intestinal disease.

4-Aminobenzoic Acid↗
PubMedDate not supplied

[Effect of paraaminobenzoic acid on interleukine-6 production in patients with herpetic keratitis].

The purpose of the study was to compare the effect of para-aminobenzoic acid (PABA) (actipol) on tear interleukin-6 (IL-6) levels in patients with herpetic keratitis and in peripheral blood cells of volunteers in vitro. Enzyme immunoassay was used to measure lacrimal fluid IL-6 levels in the actipol and acyclovir groups before and 1, 2, 3, 4, and 7-8 days after therapy and after clinical recovery in 30 patients with herpetic keratitis. A control group comprised apparently healthy volunteers (n=13, 26 eyes) who used actipol instillations into the conjunctival sac 4-5 times a day. The spontaneous production of cytokines and their production in response to the induction with different PABA concentrations (0.001, 0.01, 0.1, and 10 microkg/ml) were studied on peripheral blood cells taken from 9 volunteers. In the patients with herpetic, actipol was found to reduce and normalize tear IL-6 levels while acyclovir failed to produce this effect. In the healthy individuals, actipol did not affect IL-6 production in the anterior segment of the eye. All study PABA concentrations exerted a modulating effect on the production of IL-6 in the peripheral blood cells in vitro.

4-Aminobenzoic Acid↗
PubMedDate not supplied

Determination of fleroxacin in pure and tablet forms by liquid chromatography and derivative UV-spectrophotometry.

Derivative UV-spectrophotometric and liquid chromatographic (LC) methods for fleroxacin determination were validated. In the spectrophotometric assay, first-, second-, third-, and fourth-order measurements were applied with the use of peak-zero and peak-peak techniques. The linear correlation between amplitude of the peak and concentration of the examined drug ranged from 2.0 to 12.0 micro/mL. An isocratic LC analysis was performed on a Purospher ODS column with an acidic mobile phase containing tetrabutylammonium hydroxide. Measurements were made at a wavelength of 285 nm with 4-aminobenzoic acid (PABA) as internal standard. The calibration curve was linear (r = 0.9999) in the studied range of concentration (1.0-10.0 microg/mL). The accuracy (mean recovery, about 100%), precision (relative standard deviation < 1%), selectivity, and sensitivity of the elaborated methods were satisfactory.

4-Aminobenzoic Acid↗
PubMed1998

Inhibitory actions of glycyrrhizic acid on arylamine N-acetyltransferase activity in strains of Helicobacter pylori from peptic ulcer patients.

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene (2-AF) and p-aminobenzoic acid (PABA) as substrates were determined in Helicobacter pylori, collected from patients with peptic ulcers. The NAT activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. Inhibition of growth studies from H. pylori demonstrated that glycyrrhizic acid elicited dose-dependent bactericidal effect in H. pylori cultures, i.e.; the greater the concentration of glycyrrhizic acid, the greater the inhibition of growth of H. pylori. Cytosols or suspensions of H. pylori with and without selected concentrations of glycyrrhizic acid co-treatment showed different percentages of 2-AF and PABA acetylation. The data indicated that there was decreased NAT activity associated with increased glycyrrhizic acid in H. pylori cytosols and intact cells. For the cytosol and intact bacteria examinations, the apparent values of Km and Vmax were decreased after co-treated with 80 M glycyrrhizic acid. This report is the first demonstration of glycyrrhizic acid inhibition of arylamine NAT activity and glycyrrhizic acid inhibition of growth in the bacterium H. pylori.

4-Aminobenzoic Acid↗
PubMed1962

Increased resistance to chloramphenicol in Rickettsia prowazekii with a note on failure to demonstrate genetic interaction among.

Weiss, Emilio (Naval Medical Research Institute, Bethesda, Md.) and Harry R. Dressler. Increased resistance to chloramphenicol in Rickettsia prowazekii with a note on failure to demonstrate genetic interaction among strains. J. Bacteriol. 83:409-414. 1962.-A further effort to produce genetically labeled Rickettsia prowazekii was made by serially passing the Madrid E strain in eggs in the presence of increasing concentrations of chloramphenicol. After 40 serial and 1 limit-dilution passages, a substrain, called C(r), was isolated, which appeared to be the result of a two-step change, each involving a twofold increase in resistance to the antibiotic. Chloramphenicol resistance was retained after 10 drugless egg passages. Cross-resistance to thiocymetin, but not to unrelated drugs, was shown. Several attempts were made to demonstrate genetic interaction, in eggs or entodermal cell cultures, among strains resistant to chloramphenicol, erythromycin, and p-aminobenzoic acid. They have not been successful.

4-Aminobenzoic Acid↗
PubMed1981

The effect of test meals on the PED test.

The effects of test meals on the PFD (pancreatic function diagnostant) test, which was introduced as "the B.T.PABA test" in the previous reports, were studied. The higher the protein in the test meal, the lower the urinary excretion value of p-aminobenzoic acid (PABA) and the first 3-h of PABA excretion. By using a test meal containing protein, the differences in digestion-absorption disorders between gastrectomy procedures (Billroth I and Billroth II) were clarified. Therefore, a test meal which contains a suitable amount of protein should be used in the PFD test to improve diagnostic accuracy.

4-Aminobenzoic Acid↗
PubMed2003

Dendrimers conjugates for colonic delivery of 5-aminosalicylic acid.

The water-soluble polyamidoamine (PAMAM) dendrimer conjugates for colonic delivery of 5-aminosalicylic acid (5-ASA) were designed. The drug was bound to the dendrimer using two different spacers containing azo-bond, p-aminobenzoic acid (PABA) and p-aminohippuric acid (PAH). Incubation of PAMAM dendrimer conjugates containing PABA and PAH spacers with rat cecal contents at 37 degrees C gradually released 5-ASA with time and the amount of drug released was 45.6 and 57.0% of the dose in 24 h, respectively. The release of the drug from the commercial prodrug, sulfasalazine was significantly faster than both conjugates (80.2% of the dose in 6 h). No 5-ASA was detected from the incubation of dendrimer conjugates with the homogenate of the stomach or phosphate buffer, pH 1.2 and 6.8. Only a small amount of 5-ASA was found after incubation of both conjugates with the homogenate of the small intestine for 12 h. It appears that this PAMAM dendrimer can be developed for use as a carrier for colon-specific drug delivery.

4-Aminobenzoic Acid↗
PubMed1989

Diagnostic value of plasma PABA level in pancreatic diseases.

NBT-PABA test was performed in 72 subjects with simultaneous determination of the plasma PABA time-concentration curve. The curve in 25 controls after oral administration of N-benzoyl-L-tyrosyl-P-aminobenzoic acid (NBT-PABA) peaked (3.88 +/- 0.78 micrograms/ml, M +/- SD) at the third hour. In patients with chronic pancreatitis (24) and pancreatic carcinoma (6), the curves were flattened, and peaked at the fifth hour (2.7 +/- 1.4 micrograms/ml, M +/- SD), and fourth hour (3.14 +/- 2.26 micrograms/ml, M +/- SD), respectively. The discrimination between the controls and patients with chronic pancreatitis was most significant in the third-hour plasma PABA concentration (P less than 0.0001). This study shows that determination of the third-hour plasma PABA concentration is better in sensitivity and specificity than the 6-hour urinary excretion of PABA, suggesting that the third-hour plasma PABA concentration after oral administration of NBT-PABA might be a sensitive index of exocrine pancreatic function test.

4-Aminobenzoic Acid↗
PubMed1984

Diagnostic and therapeutic applications of bentiromide screening test for exocrine pancreatic insufficiency in patients with cystic fibrosis. Comparison with other tests of exocrine pancreatic disease.

The bentiromide test for exocrine pancreatic function was carried out in normal volunteers, patients with cystic fibrosis (CF) without clinical evidence of pancreatic dysfunction, and CF patients with clinically significant exocrine pancreatic insufficiency. The test was performed with and without the concomitant administration of a Lundh test meal. p-Aminobenzoic acid was given on a separate occasion to eliminate false positives due to factors unrelated to pancreatic disease. Correct classification of 25 CF patients with pancreatic insufficiency and 9 CF patients without clinical pancreatic dysfunction was possible by interpreting the results of the above three tests. Isoamylase determinations would have misclassified 20% of the CF patients with pancreatic insufficiency, but were able to detect the CF patients without clinical pancreatic dysfunction on the basis of an elevated pancreatic amylase isoenzyme. The bentiromide test results were normal in CF patients without clinical pancreatic dysfunction despite previous findings of decreased bicarbonate secretion in this group. However, the bentiromide test did appear to be useful in the evaluation of therapeutic intervention with exogenous pancreatic enzymes and other adjunctive therapy.

4-Aminobenzoic Acid↗
PubMed1995

Identification of a 23 kDa protein from maize photoaffinity-labelled with 5-azido-[7-3H]indol-3-ylacetic acid.

A 23 kDa protein (p23) was identified in microsomal extracts from maize coleoptiles by photoaffinity labelling with 5-azido-[7-3H]indol-3-ylacetic acid ([3H]N3IAA). Labelling of p23 was blocked by unlabelled IAA, N3IAA, indol-3-ylbutyric acid and indol-3-yl-lactate. In addition, labelling was efficiently decreased by tryptophan, as well as by the scavenger p-aminobenzoic acid. Labelling was, however, not affected by synthetic auxins such as 1-naphthylacetic acid or 2,4-dichlorophenoxyacetic acid. Competition data suggest that the label was probably bound via the indole ring, and hence labelling was not specific for auxins. The 23 kDa protein was solubilized from crude microsomes by extraction with Triton X-100 and purified to homogeneity by ion-exchange, size-exclusion and reversed-phase chromatography. After electroblotting, the amino acid sequences of the p23 N-terminus as well as the several tryptic peptides were obtained. Database comparisons revealed sequence identity with a maize manganese superoxide dismutase. We conclude that photoaffinity labelling of p23 was pseudo-affinity, and therefore the binding site for IAA is not specific.

4-Aminobenzoic Acid↗
PubMed1987

Bentiromide test is not affected in patients with small bowel disease or liver disease.

The bentiromide test reliably detects exocrine pancreatic insufficiency. The synthetic peptide attached to p-aminobenzoic acid (PABA) is cleaved by chymotrypsin, PABA is absorbed in the small intestine, partially conjugated in the liver, and excreted in the urine. It has been claimed that the bentiromide test is abnormal not only in patients with pancreatic insufficiency but also in patients with small bowel or liver disease because of impaired PABA absorption or conjugation, respectively. This study prospectively evaluates the bentiromide test in 12 patients with small bowel disease and 18 patients with biopsy-proven liver disease. One of 30 patients had an abnormal bentiromide test. Cumulative 6-h urinary arylamine excretion and plasma PABA concentration, 2 h after administration, were in the same range as healthy controls. We conclude that the bentiromide test is not affected by small bowel or liver disease. An abnormal test is virtually diagnostic for exocrine pancreatic insufficiency.

4-Aminobenzoic Acid↗
PubMed1978

Oral administration of chymotrypsin labile peptide for a new test of exocrine pancreatic function (PET) in comparison and pancreozymin-secretin test.

A new test using N-benzoyl-L-tyrosyl-p-aminobenzoic acid (N-BT-PABA) for an evaluation of exocrine pancreatic function was compared with a pancreozymin-secretin test in 38 subjects. Urinary recovery of PABA, which is absorbed from the intestine and conjugated in the liver after an oral administration of N-BT-PABA, depends mainly on chymotrypsin activity. The recovery rate of PABA in urine decreases in chronic pancreatitis, in which chymotrypsin activity in the duodenal juice is disturbed. The recovery rate of PABA in calcifying chronic pancreatitis was 40.2 +/- 15% and significantly less than 81.2 +/- 7.4% in normal subjects (P less than 0.01). The amount of PABA in urine during eight hours was correlated with parameters of volume output- bicarbonate concentration and amylase output stimulated by injections of pancreozymin and secretin (P-S test). The new test using N-BT-PABA is useful for the evaluation of exocrine pancreatic function in general practice.

4-Aminobenzoic Acid↗
PubMed1984

Drug elimination function of rat small intestine: metabolism and intraluminal excretion.

The metabolic and excretory function of the small intestine was investigated after oral and intravenous administration of drugs having an aromatic amino group to rats. After administration of drugs into the intestinal loop at the initial concentration of 0.1 mM, significant excretion of their N-acetylated forms into the lumen was observed. The amount of N-acetyl forms excreted in the lumen were 39.3 +/- 3.5, 63.5 +/- 20.9 and 18.0 +/- 13.8% of disappeared drugs from the lumen for p-aminobenzoic acid (PABA), p-aminosalicylic acid and sulfanilic acid, respectively. The excretion of p-acetamidobenzoic acid (Ac-PABA) after the absorption of PABA was reduced by the coadministration with salicylic acid, benzoic acid and 2,4-dinitrophenol. Salicylic acid noncompetitively inhibited the acetylation of PABA by the intestinal N-acetyltransferase. A good correlation was found between the intestinal N-acetyltransferase activities for drugs and the intraluminal excretion of N-acetyl derivatives after intestinal absorption of drugs. These results indicate that a drug having a higher susceptibility to intestinal N-acetyltransferase would undergo a greater excretion into the lumen in its N-acetyl form after intestinal absorption. After intravenous administration of PABA at a dose of 100 mumole/kg, 4.02 +/- 0.51% of dose was excreted in the lumen as Ac-PABA in 30 min. On the other hand, a significantly smaller fraction (2.72 +/- 0.68% of dose) was excreted in the lumen after intravenous injection of 100 mumole/kg of Ac-PABA. The larger excretion of Ac-PABA after administration of PABA indicates the contribution of intestinal metabolism on the transfer of PABA not only after oral, but also after intravenous administration.

4-Aminobenzoic Acid↗
PubMed1979

Improved diagnostic accuracy of a modified oral pancreatic function test.

The oral pancreatic function test (PFT) depends upon urinary recovery of p-aminobenzoic acid (PABA) released by chymotrypsin hydrolysis of orally administered N-benzoyl-L-tyrosyl-p-aminobenzoid acid. The diagnostic value of the test is limited because falsely abnormal results frequently occur in patients with bowel or liver disease in whom PABA recovery is impaired by abnormal absorption or hepatic conjugation, even though pancreatic function is normal. To overcome this problem, we have modified the oral PFT to correct for impaired PABA absorption and conjugation. Results of the oral PFT have been compared with urinary recovery of an equivalent dose of free PABA in order to derive a PABA excretion index (PEI). When the modified oral PFT is used, the PEI clearly distinguished patients with pancreatic disease from normal subjects. In patients with small-bowel or liver disease and normal exocrine pancreatic function, the PEI results were similar to those of normal subjects, although a previous oral PFT had been falsey abnormal. The modified test can therefore distinguish abnormal results due to pancreatic disease from the falsely abnormal results found in liver and small-bowel disease.

4-Aminobenzoic Acid↗
PubMed1986

A new criterion in the assessment of bentiromide as a test of exocrine pancreatic function in alcoholics.

Bentiromide (N-benzoyl-L-tyrosyl-p-aminobenzoic acid; Bz-Tyr-PABA) is a useful agent in the assessment of exocrine pancreatic function. Bz-Tyr-PABA is hydrolyzed by chymotrypsin in the intestine with liberation of PABA and its metabolic products, arylamines. This study was undertaken to determine the normal values for absorption and excretion of arylamines in normal volunteers and in alcoholics without detectable disorders of the pancreas, liver, or small intestine. After an overnight fast, basal blood and urine samples for baseline arylamine levels were collected, followed by oral administration of 500 mg of bentiromide. A 6-h urine collection was instituted, and 90- and 120-min plasma samples were obtained. The results were analyzed comparing normals and alcoholics: The mean concentration of arylamines was significantly higher in alcoholics than nonalcoholic subjects in baseline urine and in plasma at 90 and 120 min; no significant difference was found between alcoholics and nonalcoholics when comparing mean arylamine levels in 6-h urines. In summary, cumulative 6-h urine arylamine levels are more reliable as a criterion than 90- and 120-min plasma levels in the assessment of exocrine pancreatic function in alcoholics.

4-Aminobenzoic Acid↗