Biomedical subjects

W Berg

Publications and source records attributed to W Berg.

At least 109 records · Page 6Linked to original sources

PubMed1977

[Animal-experiment studies on the effect of magnesium and vitamin B 6 on calcium-oxalate nephrolithiasis].

By chronic intoxication with ethylene glycol or acute intoxication by Na-glyoxalate in the animal experiment a Ca-oxalatenephrolithiasis could be produced. At this model the influence of magnesium, pyridoxine and phosphate was studied. The combination therapy of magnesium and vitamin B6 can completely prevent the formation of Ca-oxalate-microliths in the kidney. The production of a preparation with 200 mg MgO and 10 mg pyridoxine per tablet for the metaphylaxis of oxalate calculi is recommended.

Animals↗

PubMed1977

[Morphological studies on the formation of oxalate stones (author's transl)].

The present paper deals with experimental and crystaloptical studies on synthetic and native Ca-oxalate. The findings are in favour of a uniform way of formation of Ca-oxalate stones from Ca-oxalate dihydrate crystals as primary crystallization product in urine, developing into the monochydrate phase by dehydratation. Rapid growth and a sufficiently high concentration of foreign ions (Mg) in the urine support the formation and stabilisation of dihydrate stones.

Calcium↗

PubMed1976

A contribution to the formation mechanism of calcium oxalate urinary calculi. I. Stabilising urinary constituents in the formation of weddellite.

25 to 30% of calcium oxalate urinary calculi consist of the metastable Weddellite crystal phase. By fractionation of urine it was found that mineral substances are stabilising factors. The stability was checked in dry condition at room temperature at 38 degrees C and at 110 degrees C. These results could be confirmed by precipitation from synthetic solutions. Mg, Zn, Ni, Co, Mn and Cu individually, and above all in combination, promote the formation of Weddellite. The formation of mixed crystal phases must be considered one of the main factors for the stabilisation of Weddelite in the urinaty calculus.

Calcium↗

PubMed1976

A contribution to the formation mechanism of calcium oxalate urinary calculi. II. In vitro experiments concerning the theory of the formation of Whewellite and Weddellite urinary calculi.

In vitro investigations of the formation of Whewellite or Weddellite are described. By means of different precipitation models the influence of cationic minerals on the formation of Weddellite could be observed. The possible conversion of Weddellite into Whewellite in vivo is demonstrated by in vitro experiments. A theory of the formation of Weddellite or Whewellite urinary calculi is developed on the basis of the results obtained.

Calcium↗

PubMed1976

A contribution to the formation mechanism of calcium oxalate urinary calculi. III. On the role of magnesium in the formation of oxalate calculi.

The influence of magnesium in vitro on the precipitation of calcium oxalate was investigated. Even at maximum physiological magnesium concentrations a litholytic effect could not be observed, but the retardation of the calcium oxalate crystallization caused by magnesium might be decisive for a reduction in calculi formation. The enlargement of the calcium oxalate crystals and aggregates caused by the retardation of crystallization, however, should be regarded as a contraindicating factor for Mg therapy in oxalate calculous disease. It is safe to say that high magnesium concentrations prevent the conversion into Whewellite of the calcium oxalate calculi substance primarily formed as Weddellite.

Calcium↗

PubMed1976

Crystaloptical and spectroscopical findings with calcium oxalate crystals in the urine sediment: a contribution to the genesis of oxalate stones.

Transmitted light microscope and scanning electron microscope investigations reveal various shapes of urine calcium oxalate crystals. In addition to tetragonal bipyramids, weddellite forms further crystal shapes that have been heretofore interpreted exclusively as whewellite crystals. Weddellite is stabilized by urine foreign ions. In vivo formation of whewellite crystals occurs with massive crystallization only.

Animals↗

PubMed1976

[Infrared-spectroscopic studies of the carbonate apatite structure of dental hard tissues].

Samples of enamel, dentine and cementum were calcined at temperatures of 500 degrees C, 800 degrees C and 1000 degrees C. The infrared spectra recorded at these temperatures were evaluated quantitatively and qualitatively. With increasing temperature, the conversion of the primarily present carbonate apatite into hydroxyapatite increased. At 800 degrees C, a hydroxyapatite proportion of 83% was found. At that, the thermal treatment produced in the dentine an increase in the degree of crystallization from 62% to 100%.

Apatites↗

PubMed1976

[Influence of anthraquinones on the formation of urinary calculi in experimental animals (author's transl)].

The growth-inhibiting influence of hydroxy-anthraquinone derivatives of root of rubia in various calcium offerings was investigated using a foreign-body bladder calculus model in rabbits. Following oral doses of glycoside-bound and free aglycemics a pronounced calcium-complex binding effect and a significant reduction in the growth rate of the calculi was observed. Use of anthraquinone glycosides to prevent recurrence of calcium-containing urinary stones is recommended.

Animals↗

PubMed1975

Uric acid dihydrate as urinary calculus component.

The analysis of uric acid dihydrate was performed using infrared spectroscopy and X-ray diffraction. Both methods permit differentiation with regard to uric acid. Pure uric acid dihydrate was prepared according to a modified technique and the dA values (lattice distances (of A) were determined from several recordings. The extreme instability of the synthetic uric acid dihydrate is stressed, and the conversion speed is determined. During the evaluation of 7,750 analyses of urinary calculi in the course of the past 3 years, 1,126 (14.5 per cent) uric acid calculi and 283 (3.7 per cent) with a mixed portion of uric acid dihydrate were found.

Drug Storage↗

PubMed1975