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PubMed1990

Detection of hippurate hydrolysis by Legionella spp. by using a rapid high-performance liquid chromatography method.

A rapid high-performance liquid chromatography method was developed to determine hippurate hydrolysis by Legionella spp. Benzoic acid, an end product of enzymatic activity, was directly detected by high-performance liquid chromatography after 1 and 24 h of incubation in 1% sodium hippurate. Because of its sensitivity, this procedure offers more precise identification of some Legionella spp.

Chromatography, High Pressure Liquid↗

PubMed1978

Hippuric acid excretion after benzylamine ingestion in man.

The fate of 14C-benzylamine after oral administration as the hydrochloride has been investigated in two male volunteers. Over 98% of the administered radiolabel was excreted in the urine as 14C-hippuric acid within 24 hours. The rate of urinary hippuric acid excretion was extremely rapid, with more than 90% of the dose excreted after three hours.

Amines↗

PubMed1986

Carbodiimide-mediated conjugation of hippuric acid to concanavalin A: retention of ligand binding and hemagglutinating activities.

Conditions for conjugating small molecules with reactive carboxyl groups to concanavalin A (ConA), with retention of biological activity of the lectin, are described. Hippuric acid was conjugated to reactive amino groups on ConA with N-ethyl-N'-(dimethylaminopropyl) carbodiimide under conditions in which neither inter- nor intra-molecular cross-linking was detectable. These same conditions provided for the loading of variable amounts of hippurate as a function of reaction time; conjugates were synthesized with 9.6 mol hippurate.mol ConA-1. Conjugation in the presence of 0.1 M phosphate provided a condition for limiting the extent of coupling; only amide linkages were formed. These conjugates retained both the ability to bind ligands and the hemagglutination titer of the native lectin.

Carbodiimides↗

PubMed1980

The influence of inhibition of prostaglandin synthesis on hippurate extraction in conscious, newborn lambs.

The influence of indomethacin (INDO) on the renal extraction of hippurate (EH) was studied in 12 conscious, newborn lambs divided into two groups based upon age. EH was measured before and after INDO (7.5 mg/kg i.v.) by collecting blood samples from both the abdominal aorta (opposite the renal artery) and renal vein (under fluoroscopy). In the youngest group (0--4 days, n = 5), control EH was 18 +/- 8% (mean +/- SE) and increased to 29 +/- 6% following INDO (p = NS). In the older animals (2--3 weeks, n = 7) control EH was 66 +/- 5% (p less than 0.001), compared to the 0--4-day-olds) and decreased to 57 +/- 4% following INDO (p less than 0.02). The results suggest that EH increases during the first weeks of life and that prostaglandins may play a role in regulating the tubular transport of hippurate.

Animals↗

PubMed2005

Neither hippurate-negative Brachyspira pilosicoli nor Brachyspira pilosicoli type strain caused diarrhoea in early-weaned pigs by experimental infection.

A hippurate-negative biovariant of Brachyspira pilosicoli (B. pilosicolihipp-) is occasionally isolated in diarrhoeic pigs in Finland, often concomitantly with hippurate-positive B. pilosicoli or Lawsonia intracellularis. We studied pathogenicity of B. pilosicolihipp- with special attention paid to avoiding co-infection with other enteric pathogens. Pigs were weaned and moved to barrier facilities at the age of 11 days. At 46 days, 8 pigs were inoculated with B. pilosicolihipp- strain Br1622, 8 pigs were inoculated with B. pilosicoli type strain P43/6/78 and 7 pigs were sham-inoculated. No signs of spirochaetal diarrhoea were detected; only one pig, inoculated with P43/6/78, had soft faeces from day 9 to 10 post inoculation. The pigs were necropsied between days 7 and 23 after inoculation. Live pigs were culture-negative for Brachyspira spp., but B. pilosicolihipp- was reisolated from necropsy samples of two pigs. The lesions on large colons were minor and did not significantly differ between the three trial groups. In silver-stained sections, invasive spirochaetes were detected in colonic mucosae of several pigs in all groups. Fluorescent in situ hybridisation for genus Brachyspira, B. pilosicoli and strain Br1622 was negative. However, in situ detection for members of the genus Leptospira was positive for spirochaete-like bacteria in the colonic epithelium of several pigs in both infected groups as well as in the control group. L. intracellularis, Salmonella spp., Yersinia spp. and intestinal parasites were not detected. The failure of B. pilosicoli strains to cause diarrhoea is discussed with respect to infectivity of the challenge strains, absence of certain intestinal pathogens and feed and management factors.

Animals↗

PubMed1990

[Application of 13C label-nuclear magnetic resonance (NMR) tracer techniques to clinical chemistry. Metabolic rate of benzoic acid to hippuric acid].

A new tracer technique, in which a 13C-labeled compound as a biological tracer and 13C nuclear magnetic resonance (NMR) as an analytical tool are used, is proposed. In order to verify the applicability of the method to clinical chemistry. [1-13C]benzoic acid was administered and [1'-13C]hippuric acid excreted in the urine was quantitated by NMR, by using [1-13C]hippuric acid as an internal standard.

Benzoates↗

PubMed2001

Hippuric acid as a modifier of calcium oxalate crystallisation.

Hippuric acid (HA) originating from the conjugation of benzoic acid with glycine is a physiological component of human urine. Findings suggest that HA inhibits calcium oxalate (CaOx) growth and considerably enhances the CaOx solubility in artificial urine. Thus, it is assumed that HA is a major modifier of CaOx formation. However, only a slight CaOx growth inhibition of 1-8% was also reported. These values were also derived from artificial urine. The key mechanism, which led HA to be of interest in urolithiasis research is the fact that in presence of Ca2+ ions HA can form a hippurate complex. By forming such a complex, Ca2+ concentration in urine decreases, and as a consequence, CaOx formation is inhibited. This study was performed in order to clarify the role of HA in native and artificial urine. Biochemical analyses to calculate the relative CaOx supersaturations and crystallisation experiments using an in-line laser probe were examined. BONN Risk Indices indicating the risk of CaOx crystallisation were calculated from the results of the crystallisation experiments. The results obtained from artificial as well as from native urines showed that HA has no significant effects on CaOx formation. We suggest that HA plays only a minor role as a crystallisation modifier in human urine.

Benzoic Acid↗

PubMed1982

[Effects of physical loads on the urinary excretion of metabolites from organic solvents. Part I. Change in the urinary excretion of glycine conjugate, hippuric acids, and glycine after a physical burden].

Effects of physical loads on the excretion of urinary glycine conjugates, which are commonly used as an index of organic solvent intake, were examined. After physical exertion by Kendo exercise university students for about 2 hours, urinary protein excretion changed from the levels of (-) or (+) before the exercise to (+) to (formula: see text) after the exercise revealed by the test-tape semi-quantitative indication, and the levels of urinary creatinine increased to approximately 1.9 time and initial level. Under the present experimental conditions, the following results were obtained. 1) Statistically no significant change was observed in the levels of urinary hippuric acid, but an increasing trend was recognized. 2) The glycine levels in the urine decreased and the significance was stressed when the values were adjusted with reference to the specific gravity of urine or to the levels of urinary creatinine. 3) The ratio of hippuric acid to the glycine in the urine increased almost twice as high as the initial ratio and the physical load seemed to promote the glycine conjugation. 4) As to the adjusted levels of urinary metabolites, especially due to several organic solvents, values adjusted with reference to the specific gravity of urine and those to the levels of urinary creatinine correlated well in the samples collected before the exertion. But a poor correlation was observed in the samples collected after the exertion. Therefore, a notice should be given when the adjustment of the values with reference to the levels of urinary creatinine, which is widely used in the health administration practice for organic solvent workers to assess the levels of exposure, since the adjusted values were lowered unnecessarily by excess excretion of creatinine after the physical exertion and the tendency would be exaggerated especially under the low level exposure to organic solvent vapours in the work yard.

Glycine↗

PubMed1985

The effects of methenamine-hippurate upon urinary risk factors for renal stone formation.

Among the various treatments for renal calcium stone disease, none has been documented to reduce urinary oxalate. Methenamine-hippurate (Hiprex) has been used extensively in the treatment of urinary tract infections and from micropuncture studies in the rat, using para-aminohippurate, it could be expected to reduce the renal secretion of oxalate. A daily dose of 3 g was given orally to 15 healthy subjects for 2 weeks. However, there was no net decrease in the urinary excretion of oxalate, but a risk index based on the urinary content of calcium, magnesium, oxalate, citrate and urine became reduced during treatment. The urinary inhibition of calcium oxalate crystal growth was unaffected. It is concluded that there may be a potential in methenamine-hippurate for the treatment of calcium stone disease, which can only be evaluated, however, by a clinical trial in stone patients.

Anti-Infective Agents, Urinary↗

PubMed1975

Accumulation of 131I hippurate in rat heart allografts during rejection.

The accumulation of 131I hippurate in heterotopic (abdominal) rat heart allografts (Brown-Norway to Lewis) in comparison with native (autologous) hearts 6 and 7 days after transplantation was studied by noninvasive scintigraphic imaging and by direct isotope counting of excised hearts. Six hours after intravenous isotope injection, isotope accumulation in the allografted heart was clearly identified by scintigraphic study in comparison with the background, kidneys, urinary bladder, and native heart. Six and 7 days after transplantation, excised allografted hearts were significantly increased in weight in comparison with native hearts. A significant increase in isotope accumulation in allografted hearts in comparison with native hearts was found both per heart and per gram of heart. The findings of this study suggests the potential usefulness of 131I hippurate in the immunoinflammatory monitoring of organ allograft rejection by direct counting as well as by noninvasive scintigraphic study if sufficient time is allowed to permit clearance of high concentrations of isotope from the background areas, kidneys, and urinary bladder.

Abdomen↗

PubMed1991

[The effect of dipyridamole on hippurate excretion in healthy volunteers and in patients with renal insufficiency].

Organic anions retained in patients with renal failure participate in a substantial way in the metabolic acidosis and thus also the catabolism in renal failure. The basic disorder is the reduced capacity of the transport system of organic ions. Therefore drugs are sought to enhance its activity. Acute investigation of healthy volunteers revealed that 150 mg dipyridamol increased the urinary hippurate excretion, while the serum hippurate concentration declined. In patients with renal failure there is the same tendency, though less marked, and due to the variability of functions of individual patients this trend is insignificant. It is assumed that this hitherto not described action of dipyridamol may be of therapeutic importance when administered to patients with impaired renal function.

Dipyridamole↗

PubMed1991

Pharmacokinetics of ortho-I-hippurate in the blood and central lymph of the rat.

The authors studied ortho-I-hippurate kinetics in the blood and central lymph in two groups of intact rats and three groups of animals with induced pathological states (cirrhosis, uraemia, malabsorption). A differentiated lipid concentration in the central lymph was induced in intact animals by depriving them of food (the unfed group) or allowing them food (the fed group) before the experiment. All the hippurate kinetic parameters, including lymphatic bioavailability (FL), in the fed group were very close to those in the unfed group, which was also used as the control for the groups with induced pathological states. Cirrhosis, uraemia and malabsorption altered the blood and lymphatic kinetic parameters in many cases, but the changes mostly followed a parallel course so that FL was maintained (except in the uraemia group, in which it fell).

Animals↗

PubMed1990

A comparative study of renal scintigraphy and clearance with technetium-99m-MAG3 and iodine-123-hippurate in patients with renal disorders.

The aim of this study was to compare kit prepared technetium-99m-mercaptoacetyltriglycine (99mTc-MAG3) with our routine radiopharmaceutical, iodine-123-hippurate our routine radiopharmaceutical, iodine-123-hippurate ([123I]OIH) for renal dynamic scintigraphy. Seventeen patients with different nephrologic disorders or hypertension were first studied with OIH and then reinvestigated with MAG3 2-8 days later. Renal MAG3 gamma camera images were almost identical with those of OIH except for higher (p less than 0.01) liver-to-background ratios at 20 min postinjection, irrespective of kidney function. Urinary peristalsis was visible longer and more clearly in the MAG3 studies. MAG3 and OIH renograms showed identical relative kidney uptake (r = 0.99), but elimination of MAG3 from the kidneys was slower (p less than 0.01). The plasma clearance of MAG3 was lower than that of OIH, but correlated (r = 0.92) significantly. The plasma distribution volume and content in blood cells was lower (p less than 0.01), but the binding of MAG3 to plasma proteins was higher, 90%, as compared with 74% for OIH, p less than 0.01. Urinary excretion expressed as a percent of the given dose 60 min after injection was the same for the two substances. Thus, there are some significant differences in the renal handling, plasma distribution, and cell penetration between MAG3 and [123I]OIH. MAG3, however, seems to have particular qualifications as a radionuclide for dynamic renal scintigraphy, especially in patients who require acute investigations or in those with low renal function.

Gamma Cameras↗

PubMed1990

Ultraviolet-absorbing organic anions in uremic serum separated by capillary zone electrophoresis, and quantification of hippuric acid.

Organic anions accumulated in blood serum of patients with chronic renal failure were separated by a novel technique: closed-system capillary zone electrophoresis (CZE) in a pH6 carrier-electrolyte system. Hippuric acid (HA), p-hydroxyhippuric acid, and uric acid were identified by their co-elution with standards prepared in ultrafiltered normal serum and by comparison with the corresponding ultraviolet-detected peaks positively identified in the HPLC analyses. Analysis time for the entire profile is 8 min. Repeatabilities (CVs) of CZE migration times and peak areas of the three acids in serum samples were about 0.7% and 6%, respectively. We quantified HA in 10 ultrafiltered uremic serum samples and compared results with those by a previously described HPLC procedure. The very good agreement further supports the identification of hippuric acid. Accuracy and precision of the CZE method were similar to those for the HPLC gradient-elution method, but analysis time for HA (8 min) is much less than by HPLC (90 min). Our technique is very suitable for selective, rapid analysis for (ultraviolet-absorbing) anionic constituents in ultrafiltered uremic serum, without any sample pretreatment.

Anions↗

PubMed1989

[Comparison of three pigment production media with CAMP and hippurate hydrolysis tests for the identification of beta-streptococcus group B].

Three pigment production media were compared with CAMP and hippurate hydrolysis tests for the identification of beta-Streptococcus group B. A total of 129 clinical isolates of beta-Streptococcus group B and 287 beta-Streptococcus non group B were tested. The results show that sensitivities are: pigment medium, 99.2%, DMS medium, 95.6%, Columbia agar, 92.8%, CAMP test, 96.3%, hippurate hydrolysis test, 97.6%. As for specificities results show: CAMP test, 99.7%, the other tests, 100%; respectively. Pigment medium is a simple, convenient methodology.

Bacteriological Techniques↗

PubMed1988

Are the classical markers sufficient to describe uremic solute accumulation in dialyzed patients? Hippurates reconsidered.

Interdependencies of accumulated solutes, analyzed by liquid chromatography in dialyzed and non-dialyzed patients, were studied by multivariate statistical analysis. In principal component analysis, three principal components (PC1-PC3) were retained from the data on 22 accumulated compounds in dialyzed patients, whereas only one principal component was retained from analogous data of a non-dialyzed patient group. PC1 in the dialyzed patient group comprises concentrations of hippuric acid, p-hydroxyhippuric acid, tryptophan, and five unidentified fluorescent solutes in serum. Concentrations of the classical markers urea, uric acid, creatinine, and phosphate were closely related to PC2 in these patients. Indoleacetic acid and two unidentified fluorescent compounds constitute PC3. The compounds associated with the groups found by principal component analysis may be characterized by chemical structure and by the mechanism of their excretion via the remaining nephrons of dialyzed patients. In the non-dialyzed group, most of the solutes could be described by a single PC. This PC and PC1 from the dialyzed group correlated significantly with residual renal function, and with total ultraviolet absorbance and total fluorescence emission. The data suggest that it is of value to introduce a marker of uremic solute retention in addition to urea, to account for renal-function-related "organic-acid-like" compounds that are excreted by renal tubular secretion in dialyzed patients. The hippurates may serve this purpose.

Chromatography, High Pressure Liquid↗

PubMed1986

[Renal excretion of total porphyrins and hippuric acid in rats].

The amounts of total porphyrins, hippuric acid and creatinine, excreted in urine by adult male Wistar rats, exhibited normal distributions for hippuric acid and creatinine, but a bimodal distribution for total porphyrins. This typical distribution of total porphyrins was still observed when creatinine was used as reference parameter. In biochemical and toxicological experiments in rats, the tested parameters should be therefore be investigated for homogeneity.

Animals↗

PubMed1979

Drug therapy reviews: methenamine mandelate and methenamine hippurate.

The mechanism of action, spectrum of antimicrobial activity, pharmacokinetics, adverse effects, therapeutic use, and dosage of methenamine hippurate and methenamine mandelate are reviewed. The antimicrobial activity of methenamine depends on its conversion in the urine to formaldehyde. Formaldehyde's spectrum of antibacterial activity encompasses all urinary tract pathogens. Urinary concentrations of formaldehyde vary with pH and urine volume; however, there is no documentation that acdification of the urine enhances methenamine's therapeutic activity. Adverse reactions to methenamine, including gastrointestinal intolerance and skin reactions, are mild and reversible and occur infrequently. Methenamine mandelate and hippurate are effective in the prevention of recurrent urinary tract infections except in patients with Foley catheters or who require intermittent catheterization.

Bacteria↗