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PubMed1984

Improvements in the routine investigation of urinary calculi.

Results from an external quality assessment program of urinary calculi analysis are shown. Some analytical improvements have been observed since a similar investigation two years earlier. Many erroneous results, however, were found. Best agreement was found between laboratories which produced results on an interval scale ("quantitative"). The laboratories in this group used either x-ray diffraction, infrared spectrometry, or wet chemistry. This, however, did not apply to the wet chemistry kit Merckognost 11003, which was used by 24 of the 57 participating laboratories. A study of this kit by our laboratory led to several improvements including better calibration and reduced imprecision. General recommendations of how to present the analytical results to the clinician are given.

Calcium Oxalate↗
PubMed1984

Urinary calculi in Lewis and Wistar rats.

A high incidence (8/892) of urinary tract calculi was encountered during a study involving rats being fed diets supplemented with retinoids. When the incidence was compared to that observed in earlier studies without retinoid supplements and spanning several years (2/2998), the incidence in the current study was significantly higher. Possible causative factors such as age, sex, strain, diet and carcinogen or retinoid treatment have been analyzed without a clear explanation for the increased incidence. The data suggest that retinoid treatment increased the risk of stone formation, but that retinoids were less important than some other unidentified factor(s) that operated during the recent period.

Animals↗
PubMed1983

Acetohydroxamate in struvite stones: in vivo study.

This report describes the results obtained with a combination of acetohydroxamic acid (AHA) and antibacterial agents in 13 patients with recurrent struvite stones complicated by refractory infections with urease-producing bacteria. Intravenous antibiotic pulses plus oral AHA achieved urine sterilisation in all. Then oral chemotherapy plus AHA was given for a mean period of 10.8 +/- 5.4 months. In four patients, the urine remained sterile, but in all the patients urinary pH remained below 6.4 and urinary NH4+ below 40 mg/dl. Despite the persistence of urea-splitting bacteria, the radiographic data showed an arrest of stone growth during the first year of treatment.

Anti-Bacterial Agents↗
PubMed1984

Evaluation of ammonium chloride as a urinary acidifier in the cat.

Twenty-four cats were fed a dry commercial cat food once daily for 2 weeks and then ad libitum for 2 weeks. Urine pH was measured 4 times daily the last 3 days of each feeding period. Subsequently, the cats were allotted to 2 equal groups and fed ad libitum an experimental, dry ration with or without 1.5% ammonium chloride for 11 months. During this period, urine pH was measured at 1, 3, 6, and 9 weeks, then monthly through 29 weeks, and then every 6 weeks for the duration of the study. When the cats were fed ad libitum, urine pH remained constant throughout the day, regardless of ration. In cats fed once daily, urine pH increased to 7.6 by 2 hours after feeding and remained between 6.6 and 7.6 for 9 hours. Urine pH remained constant throughout the study when cats were fed the experimental ration with or without 1.5% ammonium chloride, but was significantly different (P less than 0.01) between the 2 groups, 5.9 +/- 0.3 (n = 1,035) and 7.0 +/- 0.5 (n = 616), respectively. Ammonium chloride consumption had no effect on food and water consumption or body weight. It was concluded that ammonium chloride was an effective urinary acidifier for a prolonged time, maintained urine pH below 6.6, and did not decrease food intake when given at a concentration of 1.5% of the diet.

Ammonium Chloride↗
PubMed1984

Urinary acidification in the prevention and treatment of feline struvite urolithiasis.

Two groups of 12 cats were fed ad libitum an experimental dry expanded ration high in magnesium (0.37%, dry matter basis) and similar to most commercial dry cat foods in all other nutrients. The diet of one of the groups contained 1.5% ammonium chloride, which was added to the diet before processing. Urethral obstruction developed twice in 7 of the 12 cats fed the ration without ammonium chloride. Of the 5 remaining cats in that group, 2 had calculi in the urinary bladder and urethra at necropsy. In contrast, only 2 of the 12 cats fed the ration containing ammonium chloride had urethral blockage once; neither cat had another blockage. Both cats had been catheterized twice as paired controls before urethral obstruction. One of these 2 cats died from a urinary tract infection apparently introduced through the indwelling catheter, and at necropsy there were 2 small calculi in the urethra. At the end of the study, only 1 other cat fed the ammonium chloride diet had a calculus in the urinary bladder at necropsy; this cat had not had a urethral obstruction throughout the study. After each cat had 2 urethral blockages, its diet was changed. Four cats were fed the ration containing ammonium chloride and 3, a dry, commercial ration. Of the 4 cats fed the diet containing ammonium chloride, none developed another urethral obstruction within 6 months, and at necropsy, no calculi were in the urinary bladder or urethra. Two of the 3 cats fed the commercial ration experienced urethral blockage within 3 months. These 2 cats were then fed the diet containing ammonium chloride.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonium Chloride↗
PubMed1984

[Statistical analysis on 1,500 urinary calculi by using microcomputer].

In our laboratories, more than 1,500 urinary calculi have been analyzed by infrared spectroscopy. These data were statistically analyzed by microcomputer. The most frequent type was calcium oxalate combined with calcium phosphate, followed by pure calcium oxalate and magnesium ammonium phosphate combined with calcium phosphate. In particular, the composition of magnesium ammonium phosphate combined with calcium phosphate increased as compared with that four years earlier. Four years ago, we spent one month to statistically analyze 300 urinary calculi. But in this study, only sixteen days was required to analyze 1,500 urinary calculi by using a microcomputer.

Adolescent↗
PubMed1984

[A bacteriological study on urinary calculi associated with infections].

There are difficult problems in the management of urinary calculi associated with infections. Stones associated with infections are not only infection stones such as struvite stones, but also other kinds of stones such as calcium oxalate. Therefore, from practical view points, bacteriological studies should be carried out on urinary calculi associated with infections as a whole. We investigated 120 cases of urinary calculi associated with infections with special reference to bacteria on the stone surface, within the stone, compositions of the stone and permeation of an antibiotic into the stone. Proteus was isolated most frequently from the urine, followed by E. coli and Pseudomonas. These bacteria were isolated from the stone surface, although the incidence of Proteus mirabilis was higher than that in the urine. Bacteria were isolated in 25 of the 33 specimens of the inside parts and in 12 of the 12 stones of MAP and MAP plus other components. Proteus mirabilis was found in 7 of the 12 stones. Bacteria were isolated from the inside of 9 of the 16 stones of CaP and CaP plus other components and Proteus mirabilis was found in 6 of these 9 cases. Pseudomonas was isolated in 2 out of the 7 stones of CaP plus CaOX and its growth was seen in 5 specimens. The incorporation of an antibiotic, Cefmetazole, into the stone differed greatly with each stone. There were some cases in which the concentration of Cefmetazole in the inside was less than 5% of that in the outside. Stones may function as a sanctuary for organisms and may protect these organisms.

Adult↗
PubMed1983

Induction of squamous metaplasia in organ cultures of hamster trachea by naturally occurring and synthetic fibers.

Asbestos exhibits many properties of classical tumor promoters. These characteristics include the ability to stimulate proliferation and inhibit normal differentiation of cells. In organ cultures of trachea, crocidolite and amosite asbestos stimulate squamous metaplasia, a pathological process in which a rapidly proliferating squamous epithelium replaces the normal epithelium. We hypothesized that the induction of metaplasia depends upon the fibrous nature of asbestos. Accordingly, several naturally occurring and synthetic fibrous materials and their nonfibrous analogues were assessed for their ability to induce metaplastic changes in tracheal mucosa of the Syrian hamster. Exposure to both crocidolite asbestos and fiberglass resulted in significant increases (p less than 0.05) in squamous metaplasia over a range of dosages (1.0, 4.0, 16.0 mg/ml). Attapulgite (palygorskite) and both "long-" and "short-" fiber preparations of chrysotile asbestos had similar but less marked effects. Nonfibrous analogues of each material (riebeckite, antigorite, and glass particles) failed to produce metaplasia. Asbestos, and fibrous materials in general, appear to stimulate squamous metaplasia because of their fibrous geometry.

Animals↗
PubMedDate not supplied

Bilateral upper urinary tract stone.

The management of patients suffering from bilateral upper urinary tract stone presents one of the most difficult problems in urological surgery. The clinical course of 149 patients suffering from bilateral urolithiasis indicates that it has more serious consequences than unilateral stone disease in respect of postoperative recurrence, mortality, infection, and impairment of renal function. The object of this paper is to establish its incidence and the results of treatment. This enables us to assess the best policy of management in bilateral stone, using our increased knowledge of etiology and biochemical profiles, and employing the more sophisticated modern methods of complete stone removal. A more aggressive approach to bilateral staghorn calculi is considered desirable.

Apatites↗
PubMed1982

[Thermal behavior of phosphate-bonded investment. Part 1. Thermal behavior of MgNH4PO4.6H2O (author's transl)].

Thermal behavior of MgNH4PO4.6H2O was investigated by means of TG-DTA and X-ray diffraction. Two endothermic peaks (90 degrees C and 230 degrees C) and a exothermic peak (660 degrees C) were observed in a micro-DTA curve. Weight loss occurred at two stages corresponding to the two endothermic peaks. Values of weight loss were about 38% and 53%, respectively, at the end of each stage. These values were nearly equal to theoretical weight losses in the formation of Mg2P2O7 from MgNH4PO4.6H2O via MgNH4PO4.H2O. The intermediate, MgNH4PO4.H2O was identified by X-ray diffraction. The second weight loss continued till about 600 degrees C. The product during the second stage was amorphous and Mg2P2O7 began to crystallize above about 600 degrees C. The exothermic peak was thought to correspond to the crystallization. On the other hand, the first endothermic peak separated into two peaks in a macro-DTA curve. The first corresponded to removal of crystal water from MgNH4PO4.6H2O and the second to evaporation of the condensed water. Moreover the exothermic peak also separated into two peaks and the peak temperatures lowered. It was considered that the crystallization was affected by the atmosphere.

Dental Casting Investment↗