Isolation and characterization of a urobilinogenoidic chlorophyll catabolite from Hordeum vulgare L.
(1/15)
A new type of chlorophyll catabolite was isolated from extracts of de-greened primary leaves of barley (Hordeum vulgare cv. Lambic). Its constitution was elucidated by one-dimensional and two-dimensional [(1)H,(13)C]-homo- and heteronuclear NMR spectroscopic techniques and by high resolution mass spectroscopy. The isolated catabolite, a water-soluble, colorless, and nonfluorescent linear tetrapyrrole, resembles urobilinogen in which one of the propionic side chains forms a five membered isocylic ring system, indicating its origin from the chlorophylls. (+info)
Urobilinogen-i is a major derivative of bilirubin in bile of homozygous Gunn rats.
(2/15)
Gunn rats lack bilirubin UDP-glycosyltransferases, but diazo-negative derivatives of bilirubin have been described in their bile. In order to investigate this alternative disposal of bilirubin, crude bile samples from Gunn and Wistar rats were directly analysed by h.p.l.c. Besides bilirubin (in Gunn rats) or its glycosides (in Wistar rats), two major compounds were detected. A yellow one corresponded to the previously documented vitamin B-2 and was equally prominent in Gunn rats or Wistar-rat bile. The other compound was colourless, but on standing in contact with air it was spontaneously oxidized to a pinkish-yellow pigment. It was far more prominent in Gunn-rat bile. Analysis of bile obtained after intravenous injection of [14C]bilirubin to Gunn rats demonstrated that this compound was highly labelled. Freezing and thawing of the bile resulted in the formation of a series of diazo-negative derivatives, demonstrating that the original compound was quite labile. Spectral (adsorption and fluorescent) and chromatographic (h.p.l.c., t.l.c. and paper chromatography) analysis of the oxidized form of the labelled compound allowed its identification as urobilin-i. The colourless compound secreted in bile was urobilinogen-i. Administration of neomycin and bacitracin to Gunn rats or gut resection suppressed the biliary excretion of urobilinogen and thus confirmed its intestinal origin. Urobilinogen seems thus to represent the major bilirubin derivative present in Gunn-rat bile. Its breakdown products might represent the so-far-unidentified diazo-negative polar bilirubin derivatives. Since only a small amount of bilirubin is present in Gunn-rat bile, the urobilinogen formed in the intestinal lumen seems to be derived from bilirubin reaching the gut via routes other than the biliary one. (+info)
Effectiveness of an outpatient urine screening program.
(3/15)
We evaluated the effectiveness of a routine outpatient urinalysis screening program on a sample population of 2600 patients. The 189 abnormal urine results found in 182 patients were followed up by study of any new clinical and laboratory investigations or therapeutic modifications initiated on the basis of any abnormal test result. The urinalysis screening program appeared to have significant bearing on diagnosis or treatment in only 13 patients. Abnormalities found in 150 of the 182 patients were either not noted or no further positive action was taken. Thus we concluded that under the conditions of this study the urine screening program added to hospital costs without significant benefit to the patient. (+info)
Abnormal findings on dipstick urinalysis of out-patients with malaria in Abakaliki, Nigeria.
(4/15)
BACKGROUND & OBJECTIVES: Malaria, one of the major health challenges of the tropics affecting about 500 million people, particularly the children and pregnant women have been associated with changes in urine compositions. The present study was undertaken to document the urinary abnormalities in malaria patients based on malaria species and the level of malaria parasitaemia. METHODS: Febrile patients (n = 365) with positive Giemsa - stained blood films for malaria recruited from Outpatient Department of Ebonyi State University Teaching Hospital, Abakaliki participated in the study. Patients were classified into two categories (+ and ++) based on parasite density. Apparently healthy individuals (n = 81), without malaria parasite on both thick and thin films of comparable age and gender acted as control group. Urine sample (10 ml) was collected from each participant and analysed using standard laboratory methods and techniques. RESULTS: Seventy - four (20.3%) of the patients had Plasmodium falciparum malaria. Although all the urine parameters were higher in the malarial patients in comparison to the control, only bilirubinuria and urobilinogenuria were statistically significant (p <0.05). Also, bilirubinuria, urobilinogenuria, haematuria and proteinuria were significantly (p < 0.05) higher in P. falciparum infection than in infections with other malaria species, but only in P. falciparum infection, bilirubinuria and urobilinogenuria were significantly (p < 0.05) higher at higher parasitaemia. CONCLUSION: Even though positive blood film for malaria parasite remains the gold standard for the diagnosis of malaria, urinary abnormalities, such as bilirubinuria, urobilinogenuria, proteinuria and haematuria may aid in identifying patients with severe malaria parasitaemia, especially the falciparum malaria. (+info)
Reduction of bilirubin ditaurate by the intestinal bacterium Clostridium perfringens.
(5/15)
Bilirubin is degraded in the human gut by microflora into urobilinoids. In our study we investigated whether the bilirubin-reducing strain of Clostridium perfringens can reduce bilirubin ditaurate (BDT), a bile pigment of some lower vertebrates, without hydrolysis of the taurine moiety. C. perfringes was incubated under anaerobic conditions with BDT; reduction products were quantified by spectrophotometry and separated by TLC. Based on Rf values of BDT reduction products and synthetic urobilinogen ditaurate, three novel taurine-conjugated urobilinoids were identified. It is likely that bilirubin-reducing enzyme(s) serve for the effective disposal of electrons produced by fermentolytic processes in these anaerobic bacteria. (+info)
Liquid-chromatographic assay of urinary porphobilinogen.
(6/15)
This is a rapid (10 min per sample), highly sensitive procedure for quantifying urinary porphobilinogen (PBG). Interfering substances are removed by selectively adsorbing PBG onto an ion-exchange resin. After PBG is eluted with 0.5 mol/L formic acid, Ehrlich's reagent is added to produce the chromophore, which is then injected into a liquid chromatograph equipped with a diode-array detector. PBG is separated by a linear gradient (10% to 100%) of methanol in 10 mmol/L phosphate buffer, pH 3.0. Absorbance is monitored at 555 nm. Assay response varies linearly with PBG concentration over the range 0-110 mumol/L (0-25 mg/L). As little as 1.5 mumol/L (0.3 mg/L) can be detected. In prepared urine samples with known PBG concentrations, the within-run coefficient of variation (CV) ranged from 1.7% to 3.2%, the day-to-day CV from 3.5% to 6.1%. PBG concentrations in 24-h urine collected from 25 healthy subjects were all below the detection limit of the assay (less than 1.5 mumol/L). We used the new assay to measure PBG concentrations in the urine of two patients with latent porphyria. This method is more sensitive than spectrophotometric techniques currently used for measuring urinary PBG. (+info)
Establishment of a biochemically active intestinal ecosystem in ex-germfree rats.
(7/15)
A time course study for the establishment of some biochemical microbial intestinal functions was undertaken in ex-germfree rats conventionalized, i.e., colonized with conventional flora, in three different ways: untreated (group 1); contact with visitor rats (group 2); inoculated with intestinal contents from conventional rats (group 3). The first two groups of rats were inoculated with the intestinal contents from conventional rats after being out of the germfree isolators for 4 weeks. The biochemical parameters studied were degradation of mucin, inactivation of tryptic activity, conversion of cholesterol to coprostanol and of bilirubin to urobilinogen, degradation of beta-aspartylglycine, and formation of short-chain fatty acids. The results showed that the way in which the microbes were introduced and the microbial biochemical functions themselves were of importance. In several cases, social contacts, i.e., contact with visitor rats, were just as effective for the functionally adequate establishment of microbial intestinal functions as was inoculation with intestinal contents from conventional rats. Some of the biochemical parameters studied were established after a few days, whereas the establishment of others was markedly delayed. When inoculated after 4 weeks, all rats in the first two groups were colonized with conventional flora within 1 week. The results indicate that the model system described is suitable when studying buildup mechanisms in intestinal ecosystem(s). (+info)
Some aspects of bile acid and urobilinogen excretion and fecal elimination in men given a rural Guatemalan diet and egg formulas with and without added oat bran.
(8/15)
Six healthy men were fed a formula diet with and without oat bran and a natural food diet typical of rural Guatemala. No significant difference in dye transit time was found between diets but the Guatemalan diet significantly decreased dye retention time and increased stool frequency. Serum cholesterol and triglyceride levels showed no significant differences among dietary treatments. Excretion of fecal bile acids significantly increased on the Guatemalan and oat bran diets, but fecal bile acid concentration was significantly lower only on the Guatemalan diet. Urinary urobilinogen excretion and fecal urobilinogen concentration were significantly lower with the Guatemalan diet. (+info)