Search PubMed⌕ Search

Biomedical subjects

A Hesse

Publications and source records attributed to A Hesse.

At least 145 records · Page 8Linked to original sources
PubMed1980

[Citric acid excretion in stone-formers and healthy controls on normal and standard diet (author's transl)].

The citric acid excretion and concentration in 24 hours urine was measured in 70 stone-formers and 16 normal subjects (controls) on normal food intake followed by 9 days on a standard diet. On days 9 and 10 on the standard diet urine was collected in 3 hours portions and citric acid and calcium was measured. From day 7 to day 10 on standard diet we found only a slight change in the 24-hour excretion of citric acid ("steady state"). The citric acid excretion and concentration is significantly lower in stone-formers than in healthy controls. In both groups there is a sinusoid rhythm in citric acid excretion and concentration throughout the 24 hour period. The calcium concentration is at its maximum when the citric acid concentration is at its minimum.

Calcium↗
PubMed1979

A contribution to the formation mechanism of calcium oxalate urinary calculi. IV. Experimental investigations of the intrarenal crystallisation of calcium oxalate in rabbit.

Rabbits were given glyoxylic acid to induce intrarenal calcium oxalate crystal formation. The point of crystallisation in the renal tubule, the structure and the composition of the intrarenal crystals were studied. The initial crystallisation takes place in the proximal tubule. Calcium phosphate formation was excluded by microprobe examination. The comparison of the structures of the intrarenally formed crystals with those of Whewellite stones by scanning electron microscopy and the examination of isolated crystals by x-ray diffraction showed the intratubular crystals to consist of Whewellite.

Animals↗
PubMed1979

Scanning electron microscope and microprobe investigation of phosphate phases in uroliths.

In uroliths various phosphate phases can be detected which indicate different formation conditions. Structure and topography of the respective phosphate phases are characterized by scanning electron microscopy and microprobe techniques. Trace element enrichment is investigated and illustrated; for example, sulfur is found preferentially in carbonate apatite. From the distribution of the phosphate phases, conclusions can be drawn concerning the urolith genesis.

Crystallography↗
PubMed1979

[Percentiles of the neck-girth in children and adolescents (author's transl)].

Correlative calculations as to the circumference of the neck in age-conformingly developed children have revealed that neck circumference exhibits the best correlations to body weight, followed by body surface, body height, age and cervical skin thickness. The graph of the 50. percentile demonstrates sex-different course with single discontinuities of level, which are characteristic in the beginnings of school-resp. of puberal ages. The positions of the 1-s-deviations beside the 50. percentiles are almost symmetrical. An essential result of this investigations is the correction of the wide spread opinion of an age dependency of neck circumference. Instead of this, nearly linear correlation exists between body weight and neck circumference.

Adolescent↗
PubMed1978

[Analytic experiments on the significance of the fluorine content of urinary calculi (author's transl)].

The fluorine content of 150 precisely differentiated urinary calculi from areas with and without fluoridated drinking water (FDW) was quantitatively determined using different analytic methods. The fluorine content differed according to the type of calculus. With an average of 2 mg/g of calculus substance, the whewellite or weddellite concretions in FDW areas have the greatest portion of fluoride. The degree of crystallization of carbonate calculi increases with increased percentage of fluorine, and the parameter of the reticulum is characteristically contracted.

Apatites↗
PubMed1977

[Various problems in urinary calculi].

After evaluation of the essential parameters concerning urinary calculi and patient with the help of adequate computer programmes in more than 30,000 persons some conspicious trends could be established. The necessity of operative removal of calculi is still relatively high in the most frequent species of calculi whewellite, weddellite, uric acid, struvite and carbonate apatite. Thus nearly 65% of all struvite and carbonate apatite calculi must be operatively removed in women. For individual species of stones with statistical certainty (alpha=0.01) the preference of the right kidney in women and of the left kidney in men is established. The summer months bring an increased risk of stone formation. The spontaneous passages show a highly significant increase from July to October (alpha=0.01), compared with the winter and spring months.

Carbonates↗
PubMed1977

Mass spectrometric trace element analysis of calcium oxalate uroliths.

Mass spectrometric trace element analysis of whewellite and weddellite uroliths revealed 55 elements, from which 20 could be well assessed quantitatively. The total trace element content in weddellite increased by 77.5% with respect to whewellite, the main portion being made up from Na, P, Mg, and Cl. In physiological conditions weddellite is stabilized by trace elements. The importance of trace element analysis of Si, Al, Sr, Rb, S, F, Cl, and Br in uroliths is indicated.

Calcium↗
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↗