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Biomedical subjects

D Ehlers

Publications and source records attributed to D Ehlers.

At least 19 recordsLinked to original sources
PubMed1995

[Electron spin resonance spectroscopy investigations of fresh fruit. Evidence of treatment with ionizing radiation].

This paper describes the development of a method for the identification of irradiated fresh fruits by measurement of the e.p.r. spectra of pips, kernels or stones. Measurement parameters were optimized and the irradiation specific spectrum was assigned to a cellulose radical by comparison with the e.p.r. spectrum of pure cellulose. Several fruits especially different varieties of strawberries were examined giving the following results: Detectable minimum doses were between 0.4 kGy and 0.9 kGy and the intensity of the irradiation specific signals was found to be linear up to doses of 11 kGy. The lifetime of the specific radicals (at room temperature and at deep freezing temperatures) was long enough compared to the storage time of fresh fruits. Additional information about the nature of the unspecific central signal was gained measuring the samples which were stored at different temperatures. The main conclusion of this study is that the e.p.r. method seemes to be well suited for the use in routine control and should be tested in an intercomparison to establish a routine method for the identification of irradiated fresh fruits.

Dose-Response Relationship, Radiation↗
PubMed1995

HPLC analysis of tonka bean extracts.

Based on the results of GC-MS analysis, an HPLC procedure was developed for the determination of coumarin, dihydrocoumarin, melilotic acid (o-dihydrocoumaric acid), methyl melilotate, ethyl melilotate, 5-hydroxymethylfurfural and o-coumaric acid which are characteristic compounds of tonka beans. The presence of melilotic acid and ethyl melilotate in tonka beans has not been reported previously. Following HPLC analysis of tonka bean extracts produced in the laboratory and one sample of commercially available tonka bean absolute, evidence was provided that solvents used for production are decisive for the kind and amount of the compounds detected.

Chromatography, High Pressure Liquid↗
PubMed1989

Comparative studies on the adhesiveness of granulocytes of guinea pig and man.

The high affinity of granulocytes of guinea pig and man to glass surfaces is modified by serum. Native serum contains both an adherence-promoting activity, which is related to complement, and components which reduce the adhesiveness of granulocytes. These components are stable at 56 degrees C for 30 min and are tightly bound to the glass surface. beta-Lipoproteins are candidates for this adherence reducing ability of serum. Adherence promotion by native serum is mediated by coating the glass surface with C3b/C3bi. Human granulocytes from the peripheral blood adhered pig serum with C3b/C3bi to almost the same extent as in the presence of native serum, but on guinea pig granulocytes elicited in the peritoneal cavity, a cell surface metalloproteinase degraded the C3b/C3bi, thus reducing the adhesiveness of these cells. This proteinase was inhibited by MgEDTA, DTT, and 1,10-phenanthroline, whereby the high adhesiveness of granulocytes was restored to C3b/C3bi-coated glass.

Animals↗
PubMed1989

Side effects of the trypanocidal chemotherapeutics trypan blue and suramin.

Both the uptake of C3-opsonized and of nonopsonized bakers' yeast is inhibited by 1 mM trypan blue. This effect may be explained by inactivation of the C3bi-receptor. But trypan blue also inhibited the uptake of other non-opsonized particles lacking specially binding domains for this receptor. - Suramin has antiphagocytic properties at 1 mM concentration which were explained by its anticomplementary activity. However, the uptake of nonopsonized particles is also inhibited by suramin. The importance of these effects for therapeutic utilization is discussed.

Animals↗
PubMed1986

Detrusor instability in children with recurrent urinary tract infection and/or enuresis. I. Clinical conditions and symptomatology.

Forty-one children, aged 5-15 years, were referred because of recurrent urinary infections and/or enuresis. They were examined prospectively by means of cystometry. CO2 cystometry revealed detrusor instability in 18 children (44%), but if complete reproducibility were to be requested in repeated tests, only 7 children (17%) would have presented instability. Detrusor instability was not significantly related to definite pathological changes in the urinary tract or to irritative bladder symptoms.

Adolescent↗
PubMed1986

Detrusor instability in children with recurrent urinary tract infection and/or enuresis. II. Treatment.

Of 41 children, aged 5-15 years, referred consecutively because of recurrent urinary tract infections (UTIs) and/or enuresis, 18 (44%) showed detrusor instability (DI) in at least 2 of 6 CO2 cystometries. One child was excluded from the study because of lack of follow-up. Four children with less pronounced DI (instability during less than or equal to 50% of the cystometries performed) and frequent UTIs were given antibiotics prophylactically for 3 months. In the remaining 13 children, DI was found during more than half the cystometries performed, and 11 of these children, who also had urge incontinence, were treated with emepronium bromide, 400-600 mg daily (10-12 mg/kg) for 3 months. In 7 of the patients this treatment was supplemented by antibiotics prophylactically because of frequent UTIs. Two children with special problems received other types of treatment. All children were free from symptoms at a clinical check-up 6 months later, 95% confidence limits 0-20%.

Adolescent↗
PubMed1985

Value of cystourethroscopy in the assessment of children with recurrent urinary tract infections and/or enuresis.

Forty-one children ages 6-14 years consecutively referred for recurrent urinary tract infections (RUTI) and/or enuresis constituted the study group. Cystourethroscopy (CUS) was carried out in 40 children and pathologic findings were revealed in 70% of children with RUTI in the absence of vesico-ureteral reflux (VUR). However, only in 4 patients did CUS influence treatment. Based on these data we conclude that routine CUS is not justified in the evaluation of this group of children unless anatomical infravesical lesions are suspected. VUR was proven in 44% of children with RUTI. In 86% of these ureters abnormal ureteric orifices were demonstrated. We therefore find CUS to be valuable in the assessment of children with both RUTI and VUR, because this examination is helpful in selecting patients who might need operation for severe VUR. CUS was not of therapeutic benefit to children with enuresis. Five patients with macroscopic haematuria during urinary tract infection were not managed differently following CUS.

Adolescent↗
PubMed1984

Prophylactic antibiotics in transurethral prostatectomy.

The study included 88 patients with sterile urine prior to transurethral prostatectomy. Forty-five received a preoperative dose of 2 g of cefotaxime (Claforan) and the remaining 43 were given 10 ml of 0.9% NaCl. The two groups did not differ in frequency of postoperative urinary infection (greater than 10(5) colonies per ml urine); 6 patients (13.3%) in the cefotaxime group had postoperative infections during hospital stay as compared to 8 patients (18.6%) in the control group (0.5 greater than p greater than 0.3). Those in the cefotaxime group who had infections were tested for resistance. They were all fully sensitive to cefotaxime except one, who was infected with enterococci. There was no growth of bacteria from either venous blood or bladder irrigating fluid taken during the operations. Nor were any serious complications observed in any of the patients. In view of the relatively low risk of infection and the few side effects of the infections that did occur, prophylactic treatment with an antibiotic is not indicated for transurethral prostatectomy in patients with sterile urine.

Aged↗
PubMed1981

Isolation and characterization of phosphatases from vascular smooth muscle.

Actomyosin preparations of the carotid arteries of cattle contain a soluble phosphatase activity, which can be removed from the contractile proteins by repeated washings. This enzyme activity is lowered by high ionic strength, potassium fluoride, zinc acetate, ammonium molybdate, and vanadate. Magnesium ions enhance the enzyme activity. The phosphatase activity shows a maximum between pH 5.5 and 6.0 and a plateau of pH 7-9. By means of gel filtration on Sepharose 6B the phosphate activity is separated into three peaks, which are characterized with respect to their inhibition by potassium fluoride, ammonium molybate, and vanadate and their dependence on pH.

Actomyosin↗
PubMed1978

[Characterization of Ca-uptake by a microsomal fraction from vascular smooth muscle].

A microsomal fraction was isolated from the media-intima of the bovine carotid artery; the preparation is a mixed fraction of membranal and mitochondrial debris, which is able to bind Ca-ions and to take them up in the presence of ATP. The Ca-uptake is activated within a pCa range from 7--5. The involvement of two different systems in the Ca-uptake is discussed. A Ca-stimulatable ATPase was demonstrated, whose relationship with a Ca-transport system could not be established, however. The substrate for Ca-uptake is MgATP; in addition, free Mg has a stimulating effect. The Na/Kratio has no influence on the Ca-uptake. The influence of the pH-value on the Ca-binding and Ca-uptake was studied. Phosphate increased the Ca-uptake, while oxalate did not. The investigated system is discussed as a model for the action of vaso-active drugs.

Adenosine Triphosphatases↗
PubMed1977

[Experiments on the mechanism of action of vascular spasmolytics. 4. Effect of nitroprusside sodium, nitroglycerin, prenylamine and verapamil on the calcium uptake of microsomes of the smooth bascular muscles].

Nitroprusside-sodium, nitroglycerol, and verapamil had no effect on the calcium uptake by microsomes from the carotid artery of cattle. Prenylamine reduced the passive binding and the active uptake and released already bound calcium. The basal Mg-dependendent ATPase and Ca-stimulatable Mg-ATPase were inhibited by prenylamine.

Animals↗