Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor incidence was studied in 1,2-dimethylhydrazine (DMH) injected male rats assigned at weaning to isoenergetic casein-sucorse deits containing 7.5%, 15%, or 22.5% protein with or without 2.5% urea. Twenty rats fed each diet were given weekly intraperitoneal injections of DMH (15 mg/kg body weight/week) for the first 24 weeks and 20 were given saline. Of 96 DMH-injected rats necropsied after 28 weeks, 88 were necropsied during the 32nd or final week of the experiment. Adenocarcinomas of the small and large intestine were larger and significantly more numberous in rats fed 15% and 22.5% dietary protein. Keratin producing papillomas of the sebaceous glands of the external ear were observed first at 21 weeks in DMH-injected rats fed 22.5% protein. These were subsequently observed in some rats from all DMH-treated groups. As time progressed, the ear tumors increased in size and number in all groups but the greatest incidence was in the group fed 22.5% protein. No tumors were observed in saline-injected rats. Urea feeding did not increase the number of tumors nor cause changes in pH, urease activity or ammonia concentration of contents of the colon or cecum, or blood cholesterol. As dietary protein increased, cecal ammonia concentrations rose while both colon and cecal pH dropped. Portal blood urea and cholesterol reose as dietary protein was increased. DMH-treated rats had significantly higher concentrations of colon and cecal ammonia and lower blood cholesterol. Altough the rats fed 7.5% protein gained significantly less weight during 0 to 6 weeks of feeding, their weight gain was significantly higher during 6 to 26 weeks. No tumors were found in rats necropsied at 16 weeks.
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PMID:Nitrogen intake and tumorigenesis in rats injected with 1,2-dimethylhydrazine. 1 Mar 59

Lambs were fed a basal purified diet low in nickel (60 ppb) or the basal diet supplemented with 5 ppm of nickel to determine if rumen bacterial urease was a nickel-requiring enzyme. Two collection periods with lambs fed a diet in which all the nitrogen was supplied as preformed protein (casein) indicated that ruminal urease activity was much lower in lambs fed the low nickel diet. When 1% urea was added to the basal diet, urease activity increased slightly with both treatments; however, bacterial urease activity was still much higher in the lambs receiving 5 ppm of nickel. Ruminal volatile fatty acids were not influenced by dietary nickel. Ruminal urease requires nickel for maximal activity.
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PMID:Rumen bacterial urease requirement for nickel. 88 74

Forty one strains of dematiaceous fungi from the Mycology collection of the University of Costa Rica were studied. Thirty three were pathogenic (Fonsecaea pedrosoi, Cladosporium carrionii, Xylohypha bantiana, Exophiala jeanselmei, Rhinocladiella aquaspersa, Phialophora verrucosa) and the other eight were contaminants (Hormodendrum sp.). Morphological studies were done using the slide culture technique. The physiological criteria used were: urease production, gelatin and Loeffler media liquefaction; xanthine, tyrosine, starch and casein hydrolysis; nitrate utilization; carbohydrate uptake; sensitivity to cycloheximide and thermotolerance in glucose-Sabouraud medium. The physiological tests did not provide characteristic patterns for the different genera of pathogenic fungi, even though these differences were detected in non pathogenic fungi; the tests may be useful for the quick separation of both groups. Physiological test may have a limited value in the identification of fungi and the morphological analysis cannot be substituted by physiological studies.
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PMID:[Morphologic and physiologic characteristics of Costa Rica pathogenic fungi (Dermatiaceae)]. 184 48

Three cases of great toenail infection are described in which a slow-growing arthroconidial hyphomycete was isolated repeatedly and in pure culture. Direct microscopy revealed hyaline, round to barrel-shaped arthroconidia, hyaline hyphae of varying width, and broad thick-walled brownish hyphae. Three additional isolates were obtained from clinical specimens, for which the results of direct microscopy were unknown or negative. The fungus was resistant to cycloheximide, sensitive to common antifungal drugs by susceptibility tests in vitro and sensitive to benomyl. It was urease positive, hydrolysed casein and tyrosine but not xanthine or hypoxanthine, showed no specific nutritional requirements but grew better on carbohydrate-free media, assimilated 12 carbohydrates and potassium nitrate, and failed to perforate hair. The fungus is described as Onychocola canadensis Sigler gen. et sp. nov., and it is compared to Scytalidium lignicola, Scytalidium hyalinum and the Scytalidium synanamorph of Nattrassia mangiferae (Hendersonula toruloidea).
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PMID:Toenail infection caused by Onychocola canadensis gen. et sp. nov. 214 86

Urease activity was measured using whole cells of both long (swarming) and short (nonswarming) populations of Proteus mirabilis from casein hydrolysate agar (CHA) and broth (CHB) cultures, and from brain heart infusion broth (BHIB) cultures. Urease is a constitutive enzyme for both long and short cells, but its activity was tremendously increased when urea was incorporated into the media. Urease production was also affected by culture age and media used. Before exponential phase, urease activity was very low, and it increased to its highest point after about 4 h in BHIB and 8 h in both CHA and CHB cultures at 37 degrees C. Long cells had higher urease activity than did short cells when grown on CHA, and was also expressed by two different strains cultured in BHIB. Strain PM23, in BHIB, was able to form long cells (swarming cells) to a maximum proportion after about 4 h, but strain IM47 could not differentiate in any of the liquid media. The former had more urease when swarming differentiation was initiated. PM23 grew relatively faster than IM47 when the former began to differentiate, but this fast growth could not be observed when nutrient broth or minimal medium was used. These observations suggest that long or swarming cells are "faster growing" rather than "nongrowing bacteria".
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PMID:Urease activity related to the growth and differentiation of swarmer cells of Proteus mirabilis. 329 70

Scolecobasidium humicola, a soil fungus and etiologic agent of phaeohyphomycosis in fish, is herein reported to cause cutaneous lesions in a tortoise, Terrapine carolina var. carolina. S. humicola was isolated from lesions on the foot and dematiaceous hyphae were observed in KOH preparations of the biopsy and in stained preparations. This isolate and others were compared morphologically and physiologically with isolates of Dactylaria gallopava which it resembles. As a result of this investigation, we concluded that D. gallopava may be differentiated from S. humicola macroscopically, by the production in D. gallopava of an extensive diffusible purplish-red to reddish-brown pigment when cultured on Sabouraud dextrose agar; microscopically, by the presence and usually predominance of conidia, whose apical cell is markedly wider than the basal cell, and usually constricted at the septum; and physiologically, by the ability to grow on media containing cycloheximide and by the ability to grow well at 36-45 degrees C. In contrast, S. humicola does not usually produce a diffusible pigment on Sabouraud's dextrose agar or if present, is not extensive; it lacks the wider upper cell; is less constricted or non-constricted at the central septum; grows on media containing cycloheximide, although some inhibition may occur and lastly, does not grow at 36 degrees C or higher. Both species were urease positive, hydrolysed tyrosine but not casein, xanthine, or gelatin.
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PMID:A comparison between Dactylaria gallopava and Scolecobasidium humicola: first report of an infection in a tortoise caused by S. humicola. 404 87

Monoconidial cultures derived from 12 clinical and environmental isolates of Phialophora parasitica were compared with respect to morphologic and physiologic characteristics and response to antifungal agents. No yeast cells were seen in 1- and 3-week-old slide culture preparations. Also, not all of the distinguishing characteristics of this species were displayed by all isolates on all media examined. Although the isolates grew on Sabouraud agar with chloramphenicol and cycloheximide, some inhibition was observed. All cultures were strongly urease-positive and hydrolyzed casein and starch; most decomposed tyrosine but not gelatin. All but one environmental isolate grew well at both 23 and 37 degrees C, but none grew at 40 degrees C. In the sensitivity testing the isolates did not vary much in their response to each drug, although some anomalies were observed. Amphotericin B and miconazole had minimum inhibitory concentrations in the low sensitivity range (2.0-8.0 and 2.5-10 micrograms m-1 respectively), for most isolates, and most isolates were resistant to both 5-fluorocytosine and ketoconazole. Limited observations were made on three other Phialophora species which might be confused with P. parasitica.
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PMID:Phialophora parasitica, an emerging pathogen. 609 71

A study, conducted with 20 isolates of Microsporum ferrugineum and 12 isolates of Trichophyton soudanense, revealed that some of the discrepancies in the literature regarding their characteristics and differentiation were due to methodology, strain variation and the use of an insufficient number of isolates. We found all isolates of T. soudanense to be urease negative and gelatinase positive (usually by the first week); to produce brown to black colonies on Lowenstein-Jensen medium; to rapidly decompose casein and more slowly tyrosine; to grow well or better at 37 degrees C as compared to room temperature; to produce reflexive branching on cornmeal Tween agar and abundant microconidia on casero medium and to exhibit no sexual reaction with either mating type of arthroderma simii. All but one isolate demonstrated restricted growth on lactose agar and only three isolates perforated hair. In contrast, we found 18 of 20 isolates of M. ferrugineum to be urease positive in urea broth (most isolates were negative on urea agar); all produced light-colored colonies on Lowenstein-Jensen medium; spreading colonies on lactose agar and failed to perforate hair in vitro or to produce reflexive branching. Most isolates manifested poorer to no growth at 37 degrees C compared to room temperature and all but one failed to decompose casein and tyrosine. A few strains produced macroconidia and/or microconidia on casero medium and some reacted sexually with A. simii (a) (-) mating type. Gelatin hydrolysis was variable.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies in the differentiation between Microsporum ferrugineum Ota and Trichophyton soudanense Joyeux. 637 42

This study was conducted to study chemically and serologically the characteristics of the Ureaplasmas isolated from the human oral cavity. Two hundred and fifty-one healthy and 12 periodontitis subjects were examined for the incidence of the isolation of Ureaplasmas from their oral cavity. A total of twenty-six strains was isolated from the healthy human saliva. But no strains could be isolated from a variety of clinical specimens obtained from the patients. The serological properties of the isolates were tested by the method of metabolism inhibition test (MI test). Seven out of 26 isolates were serologically identical with either one of the ATCC standard strains. However, the serological types of the other strains could not be demonstrated by the MI test. The biological characteristics of 4 isolates and ATCC strains were tested by the usual method. The isolates did not metabolize glucose and arginine, while all strains hydrolyzed urea. On the other hand, none of the isolates lysed skimmed milk and gelatin. The proteolytic activity of the isolates could be demonstrated by using casein and horse serum proteins as substrates. Zymogram patterns from one of the isolates and Streptococcus salivarius were obtained by polyacrylamide gel electrophoresis of the cells lysed with digitonin or cell protein extracts. On the basis of the gel electrophoresis patterns, it is clear that the urease of the Ureaplasma is different from that of the Streptococcus salivarius.
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PMID:Biochemical and serological studies on oral ureaplasma. 659 16

The antioxidant activity of skim milk was evaluated in a linoleate emulsion system with hemoglobin as a pro-oxidant. Sonication greatly increased the antioxidant activity of skim milk. The antioxidant activity of the casein fraction of milk was increased most by sonication, and this increase was nearly as great as that for skim milk, suggesting that casein was almost totally responsible for the antioxidant effect of sonication. Total sulfhydryl groups of skim milk decreased upon prolonged sonication, probably the result of the heat evolved in the process. Reactive sulfhydryl content was unchanged by sonication. Sonication had no effect on antioxidant activity of beta-lactoglobulin, reduced urease, or reduced ribonuclease, proteins with free sulfhydryl groups. Apparently sulfhydryl groups were not involved in the increased antioxidant activity of sonicated skim milk. Homogenization at 281.5 kg/cm2 did not increase the antioxidant effect of skim milk. Sonication probably disrupted casein micelles, increasing the effective concentration of casein, which could account for the increased antioxidant activity in the system.
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PMID:Antioxidant activity of skim milk: effect of sonication. 689 12


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