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PubMed1988

The effect of pyrophosphate on the reaction of myosin with 2,4,6-trinitrobenzene sulphonate.

Myosin was reacted with 2,4,6-trinitrobenzene sulphonate (TNBS) in the presence or absence of Mg-pyrophosphate. The reaction led to trinitrophenylation of lysyl residues which could be divided on the basis of the reaction into three classes: (i) two rapidly reacting lysyl residues (RLR), one residing on each head of myosin, whose rate of reaction depends on the presence of Mg-pyrophosphate; (ii) two lysyl residues which react with intermediate rate (ILR) and reside on the rod segment of myosin; and (iii) the remaining lysyl residues of myosin which react slowly with TNBS. The rate of the trinitrophenylation of RLR was followed spectrophotometrically and enzymatically, measuring an absorbance change at 345 nm, and also changes in K+ (EDTA)-, Mg2+- and Ca2+-activated ATPase activities, respectively. According to analysis of the kinetics of the reaction, Mg-pyrophosphate inhibited the rate of trinitrophenylation in both heads of myosin, not in one head only as was suggested by Miyanishi et al. (J. Biochem Tokyo 85; 1979). Myosin heads (myosin subfragment-1, S-1) were prepared by digesting myosin trinitrophenylated in the absence and presence of Mg-pyrophosphate with chymotrypsin. S-1, with trinitrophenylated RLR, was separated from non-trinitrophenylated S-1 by DEAE cellulose column chromatography. The trinitrophenylated S-1 had a high Mg2+- and a low K+(EDTA)-activated ATPase while the non-trinitrophenylated species had the usual high K+(EDTA)- and low Mg2+-ATPase activity. This results excluded the possibility suggested by Miyanishi et al., that the myosin head, which is resistant to trinitrophenylation in the presence of Mg-pyrophosphate, did not possess K+(EDTA)-activated ATPase activity. The presence of Mg-pyrophosphate during trinitrophenylation substantially affected the enzymic characteristics of the modified myosin. The myosin trinitrophenylated in the presence of Mg-pyrophosphate had a higher K+(EDTA)- and a lower Mg2+-ATPase activity. SH1 (Cys-707) also probably becomes a target of the reaction if myosin is trinitrophenylated in the presence of Mg-pyrophosphate. This is deduced from the following findings: (i) the addition of dithiothreitol after trinitrophenylation partially reversed the loss in the K+(EDTA)-ATPase activity; and (ii) the specific alkylation of the SH1 thiol by 1,5-IAEDANS prior to trinitrophenylation prevented the effect of dithiothreitol on the ATPase activity of myosin. The results indicated that Mg-pyrophosphate induced structural changes in the myosin molecule which influenced the course and possibly the target(s) of trinitrophenylation.

Adenosine Triphosphatases↗
PubMed1985

Bacteriological study of renal calculi.

The pre-operative urine, pelvic urine, removed calculi and calculus washings were examined bacteriologically in 24 patients undergoing removal of intrarenal calculi. Four of seven patients with struvite calculi had an infected pre-operative midstream urine specimen and six of the seven removed calculi demonstrated significant bacterial growth. Proteus mirabilis was the commonest organism isolated. Of 17 patients with oxalate calculi only one had an infected pre-operative urine culture, but in four cases the removed stones were infected. Quantitative bacteriological culture of the stones and their washings demonstrated that infection is within the stone itself. Pre-operative urine culture failed to predict infection within the stone in 60% of patients with infected stones. The results suggest that the presence of infected urine together with the presence of renal calculus is indication for removal of the calculus.

Adult↗
PubMed1984

Applicability of biosuppressin as an urease-inhibitor.

Prevention of the formation of struvite and carbonate-apatite calculi, which rapidly increase in size and tend to recur, is of prime importance. One of the urease inhibitors, hydroxycarbamide, was studied in vitro. The results are favourable and justify further studies aimed at the local application of the inhibitor.

Ammonia↗
PubMed1986

S.E.M. study of urease-induced crystalluria in the presence of hydroxamic derivatives.

The effect of 3 hydroxamic acid derivatives on urease-induced crystalluria was studied in vitro. Acetohydroxamic acid is more effective than salicylhydroxamic and gentisohydroxamic acids in inhibiting the kinetic of urease enzymatic reaction and in retarding the formation of struvite and apatite. Crystal deposits studied by scanning electron microscope (S.E.M.) and X-ray microanalysis indicated that acetohydroxamic acid favours the formation of large crystals of struvite, and less aggregation is observed. Salicyl and gentiso derivatives favour the formation of brushite together with struvite and apatite.

Apatites↗
PubMed1990

Changes in some nutrients of fenugreek (Trigonella Foenum graecum L.) seeds during water boiling.

Fenugreek seeds were boiled in water for various lengths of time (5, 10 and 15 min). Changes in weight, volume, moisture content, total sugars, nitrogen compounds, minerals, phosphorus compounds, phytic acid, amino acids and the in vitro digestibility of the seeds as well as the total solids of the boiling water were determined. Data indicated that there was an increase in both weight and volume as well as the in vitro digestibility of fenugreek seeds especially after the first 5 minutes of boiling. On the other hand, a decrease in the content of total sugars, protein compounds, calcium, magnesium, phytic acid, phosphorus and amino acids was observed. The reduction was accompanied by a gradual increase in the total solids of boiling water.

Amino Acids↗
PubMed1989

Experiments with extracorporeal shock wave nephrolithotripsy.

Two sets of experiments were carried out on 14 live rabbits having renal calculi from nephrolithiasis patients implanted in their kidneys. Shock waves were used to disintegrate the implanted concrements. It took 100 to 150 sound pulses to crush struvite stones to fragments less than 2 mm in size, with 400 to 800 pulses needed to destroy calcium oxalate stones. After multiple exposures to shock waves there were no indications of any gross damage to the soft tissues of the experimental animals. Mechanisms for destruction of kidney stones by shock waves were considered.

Animals↗
PubMed1991

The origin and causes of struvite stones.

The aim of this paper is to evaluate the possible causes of the origin of "infection stones". The main differences between the ordinary biochemical parameters of a group of patients with this type of stones was analyzed and compared with a group of oxalocalcic stone-formers and with a group of healthy subjects. The importance of persistent basic urinary pH values is pointed out as possible origin of "infection stones" in some instances. The main urinary citrate concentration in patients with "infection stones" was significantly lower than in healthy subjects, this being an important factor that favours this kind of stone formation.

Calcium Oxalate↗
PubMed1997

Intravenous aminophylline increases the degree of saturation of urine with calcium phosphate and struvite.

This study was designed to assess the effect of i.v. treatment with aminophylline (AMPH) on the risk of calcium phosphate and struvite stone formation. We administered AMPH in doses of 4 mg/kg body weight in 15-min i.v. infusions to 60 infants with clinical symptoms of obstructive bronchitis with dyspnoea. During 3 hours after infusion we observed a significant increase in urine saturation with brushite, octocalcium phosphate and struvite. This rise in urine saturation may increase the risk of kidney stone formation.

Aminophylline↗
PubMed1988

Presence of lipids in urinary stones: results of preliminary studies.

The presence of lipids in urinary stones was determined by histochemical and biochemical methods. When crystals of calcium oxalate, made by mixing calcium chloride and potassium oxalate solutions and sections of human calcium oxalate urinary stones, were exposed to osmium vapors, there was no staining of the pure crystals whereas the stone sections were stained. De-paraffinized sections of demineralized calcium oxalate stones showed positive sudanophilia on staining with Sudan black B. Both these experiments indicate the presence of lipids in calcium oxalate stones. Lipids were extracted from uric acid, struvite, and calcium oxalate stones using standard techniques. Phospholipids were separated by one-dimensional thin layer chromatography. All the stones studied contained lipids. In calcium oxalate stones they accounted for 10.15% of the matrix. Calcium oxalate and struvite stones contained more phospholipids than uric acid stones. Cardiolipin, sphingomyelin, phosphatidyl choline, phosphatidyl inositol, phosphatidyl ethanolamine, phosphatidyl serine, and phosphatidyl glycerol were identified in lipid extracts. Demineralization by ethylenediaminetetra-acetate (EDTA) treatment increased lipid output from calcium oxalate stones by 15.5%.

Calcium Oxalate↗
PubMed1991

Epidemiology of urolithiasis in the elderly.

To estimate the epidemiology of upper urinary stones in the elderly, a total of 1,957 patients (1,349 men and 608 women) with urolithiasis were studied. The ratio of men to women was approximately 3:1 in middle-aged (between 30 and 59 years), 1:1 in young (29 or younger) and 1:1 in old patients (60 or older). Compared with the age distribution of the entire Japanese population, the incidence of urinary stones was very low in both male and female children, twice as high in middle-aged men, slightly higher in middle-aged women, and equal or slightly lower in the male and female elderly. Stones of calcium oxalate and uric acid occurred more frequently and those of calcium phosphate and struvite less frequently in men than in women. This tendency was especially obvious in the middle-aged. In the old generation, calcium oxalate stones occurred almost equally in men and women. Results of urinary stone analysis were similar among men of the three generations, although the incidence of uric acid stones increased with patient age. In women, however, the incidence of calcium oxalate was higher in the young and old generations, while that of calcium phosphate was higher in the middle-aged.

Adolescent↗
PubMed1989

Struvite crystal precipitation by different phenotypes of Yersinia.

Extracellular formation of struvite crystals by Yersinia enterocolitica, Y. frederiksenii, Y. kristensenii and Y intermedia strains was investigated. Precipitation of crystalline structures was found with 19 of the 187 strains tested, its formation being more frequently observed at 25 degrees C than at 37 degrees C. Production of struvite was greater in Y. enterocolitica strains belonging to biotype 1, serogroup 0:7,8 and lysotype Xz, than observed in other phenotypes. Quantitative assay in a liquid medium showed that struvite formation began after 3 d of incubation; production of these crystals increased up to 15 d. Crystalline structures were examined using electron microscopy and their extracellular formation was observed.

Crystallization↗
PubMed1991

Use of micronucleic test for the determination of genotoxicity of waste liquor from a magnesium bisulfite pulp mill.

Since diluted magnesium bisulfite waste liquor from a pulp mill after beech wood processing exhibited an inhibitory effect on all the model organisms used in our previous work (Cernáková et al. 1991) and the results of Ames mutagenicity test were ambiguous, micronucleic test was used for characterization. The frequency of micronuclei observed suggested that the diluted magnesium bisulfite waste liquor had a mutagenic effect under in vitro conditions of the micronucleic test.

Female↗
PubMed1984

Pathogenesis of renal calculi.

Urolithiasis involving the upper urinary tract is a multifactorial disease that remains a significant health problem. A variety of intrinsic and extrinsic factors influence the incidence of disease in individuals and in all populations. At the level of the kidney, natural physicochemical processes result in crystalluria and the formation and growth of stones. Urinary supersaturation of some degree must be present but its significance may be altered by changes in urinary volume, pH, epitaxial relationships, and the presence or absence of naturally occurring inhibitors. A variety of environmental parameters acting through effects on the local urinary conditions determine which patients among a group of people inherently at risk will form stones. The above factors are considered herein with regard to the four major types of stone disease encountered today.

Adult↗
PubMed1984

Nephrolithiasis: current concepts in medical management.

Advances in renal lithiasis research have contributed to a better understanding of the many varied factors that contribute to renal calculus formation. Utilizing the newer techniques of ambulatory metabolic evaluation, we can establish a specific diagnosis in 95% of recurrent stone-formers. Since a significant percentage of initial stone-formers will never have a second episode, it is essential to establish the natural history of the patient's stone disease prior to initiating potentially life-long medical therapy. The majority of initial stone-formers can be managed with education concerning modest dietary restrictions and increased fluid intake. For the recurrent stone-former with metabolically active stone disease, it is probably best to design medical therapy to treat the specific urinary chemical abnormality or disease process.

Acidosis, Renal Tubular↗
PubMed1999

Biomineralization of carbonates by Marinococcus albus and Marinococcus halophilus isolated from the Salar de Atacama (Chile).

We studied the precipitation of carbonates in 17 strains of moderately halophilic, Gram-positive cocci belonging to two species: Marinococcus halophilus and Marinococcus albus, isolated from the Salar de Atacama (Chile). They were cultivated in solid and liquid laboratory media for 42 days at salt concentrations (wt/vol) of 3%, 7.5%, 15%, and 20%. The bioliths precipitated were studied by X-ray diffraction and scanning electron microscopy. M. halophilus formed crystals at each of the salt concentrations, with a maximum number of strains capable of precipitating carbonates at 7.5% and 15% salt concentrations. M. albus did not precipitate at 20% and showed a maximum at 7.5%. This behavior is similar to that of other gram-positive bacteria and differs from that found in gram-negative bacteria. The bioliths precipitated were spherical, generally isolated, with a size of 10-100 microm, varying with salinity. They were of magnesium calcite (CO3 Ca1-x Mgx) with Mg content increasing with increasing salinity and Mg/Ca molar ratio of the culture medium. These results demonstrate the active role played by M. halophilus and M. albus in the precipitation of carbonates.

Carbonates↗
PubMed2003

[Infection-induced urinary stones].

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease-positive urinary tract infection. Urease is necessary to split urea into ammonia and CO(2). As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals are deposited infection stones form. Pathogenetically, various risk factors play a role: urinary obstruction, neurogenic bladder, dRTA, and MSK. If these infections are not treated and the stones are not removed, the kidney will be damaged. Modern methods are available for stone removal, e.g., ESWL and/or instrumental urinary stone removal. Here, especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences, and new infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

Apatites↗
PubMed2006

[Plasma-deposited carbon coating on urological indwelling catheters: Preventing formation of encrustations and consecutive complications].

BACKGROUND: Any material placed in the urinary tract is susceptible to the formation of encrustations of crystalline bacterial biofilms. These biofilms cause severe complications in some cases. The strategies used so far for reduction of these complications by surface modifications of the implant material failed to show the expected results. PATIENTS AND METHODS: In this study, we investigated amorphous carbon coatings (a-C:H) for their ability to effectively reduce or to repress the progressive formation of infection-enhancing crystalline biofilms as new functional surface coatings. In nine patients suffering for several years from stenting, a-C:H-coated ureteral stents were tested in treatment attempts. The current replacement intervals amounted to a mean of 77 days; the principle cause for early replacement was massive stent encrustations associated with symptomatic urinary tract infections. RESULTS: In total, 20 coated ureteral stents were tested spanning indwelling times between 3 and 4 months. No stent-related complications occurred. In all cases extraordinarily facile handling, less pain during replacement, and markedly increased tolerance were observed. Symptomatic urinary tract infections were reduced by more than 50%. The stents remained virtually free of encrustations. CONCLUSION: a-C:H coatings are a novel strategy leading to an enhancement of long-term applicability of ureteral stents and catheters and to improved patient comfort.

Adult↗