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Biomedical subjects

K Winnefeld

Publications and source records attributed to K Winnefeld.

At least 37 records · Page 2Linked to original sources
PubMed1994

The ambiguous effect of ascorbic acid on chromate induced proteinuria in rats.

The influence of ascorbic acid (AA, 5 g/kg body weight) on chromate (Cr, 10 mg/kg) induced proteinuria, which is a sensitive parameter of its nephrotoxicity, was investigated in adult female Wistar rats. The concentrations of Cr and ascorbic acid (AA) were determined in renal tissue. Cr nephrotoxicity is related to its intracellular reduction from Cr(VI) to Cr(III). Proteinuria was completely prevented by enhancement of extracellular reduction of Cr(VI) to Cr(III) followed by rapid renal excretion when Cr and AA were given concomitantly. With an interval up to 1 h between Cr and AA, proteinuria was decreased probably by the radical scavenging function of AA. At an interval of 3 h AA enhanced Cr toxicity by increased intracellular Cr reduction. If the interval was increased to 5 h or if Cr was given 24 h after AA, no influence of AA could be detected. Our results confirm that AA is a very effective reductant of Cr which can influence Cr nephrotoxicity in very high concentrations. It depends on the interval between Cr and AA administration whether or not there is a beneficial effect of AA in Cr nephrotoxicity.

Animals↗
PubMed1993

Role of glutathione for cisplatin nephrotoxicity in young and adult rats.

Investigations were done in 10- and 55-day-old Wistar rats. Glutathione (GSH) level in kidney was decreased by 8 mmol buthionine sulfoximine (BSO)/100 g BW. There was no effect on the renal function and nephrotoxicity of cisplatin (0.6 mg CP/100 g BW) in adult rats. In young rats BSO treatment was followed by nephrotoxic effects. Pt concentration remained unaffected by BSO in young and adult rats. GSH concentration in kidney was increased by 100 mg acetyl-cysteine (accys)/100 g BW. CP nephrotoxicity was lower in young as well as in adult ac-cys-treated rats. Pt levels in renal tissue were significantly decreased in rats from both age groups. From our results we conclude that the beneficial effect of high GSH concentration in renal tissue on CP nephrotoxicity is the result of decreased Pt concentration in kidney.

Acetylcysteine↗
PubMed1991

[Clinical, infrared spectroscopic and chemical analysis of bile duct and gallbladder stones].

By means of concrements, which were obtained endoscopically by extraction from the bile duct, and of gallstones, which were given the patient by the surgeon on the occasion of the gallbladder operation, we performed stone analyses with the aid of infrared spectroscopy and compared them correlatively with clinical and case history data. The paper focussed on the detection of the stony structure of choledochal concrements, separated into stone core and stone mantle. A method for the reliable differentiation of stones left (residual stones) from new formations (recurrent stones) in the bile ducts has not been possible to date. Thus, the burning question of the surgeon cannot be answered with certainty. However, there is no doubt about surgical suture material as incrustation core for a pigment stone in terms of a true recurrent stone, which poses a real challenge to biliary tract surgery.

Bile Pigments↗
PubMed1991

[Behavior of selenium in serum and erythrocytes in females with normal and risk pregnancy (pregnancy-induced hypertension, fetal retardation and hepatosis)].

In the course of normal pregnancy the selenium concentration in serum decreases significantly. The selenium concentration is enhanced in pregnant women with intrauterine growth retardation or hepatosis and unchanged in those with pregnancy-induced hypertension in comparison with healthy pregnant women. In our investigations no changes of the intracellular selenium concentrations in erythrocytes were measured in normal as well as in pathological pregnancy.

Erythrocytes↗
PubMed1990

[Magnesium level in serum and erythrocytes in patients with chronic coronary heart disease without myocardial infarct].

In 62 patients with chronic coronary heart disease without myocardial infarction the magnesium content of the serum and the erythrocytes was determined by means of the flame atom absorption spectrophotometry in comparison to patients with infarction and a group of healthy test persons. In the patients with chronic coronary heart disease without acute myocardial infarction the magnesium content of the serum was significantly reduced on the first day after the pectanginous attack. No decreased magnesium level of the erythrocytes was present on the first and tenth day after the pectanginous attack.

Adult↗
PubMed1990

Triiodothyronine (T3) increases cisplatin nephrotoxicity in young and adult rats.

The influence of pretreatment with triiodothyronine (T3) on cisplatin (CP)-induced nephrotoxicity was investigated in 10- and 55-day-old rats. Triiodothyronine pretreatment enhanced CP proteinuria in young and adult rats, and increased blood urea nitrogen concentration in 55-day-old rats. As T3 decreased Pt concentrations in renal tissue, the enhanced nephrotoxicity of CP by T3 must have another mechanism. Enhanced CP nephrotoxicity is discussed in connection with an increase of glutathione concentration obtained in renal tissue as a consequence of T3 pretreatment.

Aging↗
PubMed1989

[The function of hemoglobins].

Haemoglobin is primarily responsible for the oxygen supply and a normal acid-base economy in mammals. An optimal loading of haemoglobin with oxygen in the lungs and a high desaturation in the periphery are ensured by a highly cooperative oxygen binding of 4 subunits as well as by different effectors--2,3 DPG, chloride, pH, temperature...-.A number of differently built-up haemoglobins will ensure a sufficient oxygen supply of individual ontogenetic stages of development in the human organism.

Biological Transport↗
PubMed1989

[The diagnostic value of CT in siderophilia (primary idiopathic hemochromatosis)].

CT, due to its high resolution of density, is suitable, within certain limits, to quantify iron contents in the liver. - Diagnostic value and limits of dual-energy-computed tomography after 38 examinations, 31 of them in patients with verified haemochromatosis, are described: In a progressive state of iron overload a high correlation exists between results of computed tomography and usual reference methods of iron metabolism (iron determination by absorption spectrometry and histologic examination, serum-iron-level, serum-ferritin-level, relative transferrin saturation, desferal test). - With a specificity of nearly 100% CT shows a minor or medium iron overload only with low sensitivity. - Because of its noninvasive nature CT is an alternative method of biopsy in progressive liver disease with suspected hepatic siderosis.

Fatty Liver↗
PubMed1988

Nephrotoxicity and pharmacokinetics of cisplatinum in young and adult rats.

Wistar rats (10 and 55 days old) were administered a single dose of 0.6 mg cisplatinum (CP) 100 g body wt. intraperitoneally. Urinary volume, p-aminohippurate and total protein excretion were determined. Separation of urinary proteins was performed by sodium dodecylsulfate polyacrylamide gel electrophoresis. Significant symptoms of nephrotoxicity (oliguria, reduced PAH-excretion, heavy proteinuria, changes in urinary protein composition) were detected in adult rats 72 h after CP. At that time young rats did not show distinct signs of nephrotoxicity. Experiments on time dependence of nephrotoxicity showed that in young rats symptoms occurred already 6 h after CP-administration, and 72 h after CP the damage was nearly completely repaired. Pt-determination in serum, kidney tissue, and urine showed a shorter t1/2 in serum, lower concentrations in kidney tissue as well as higher Pt-concentrations in urine of young compared with adult rats.

Aging↗
PubMed1988

[Pharmacokinetics and nephrotoxicity of aluminum in rats of various ages].

Experiments were done in 5-, 10-, 20-, 33-, 55-, and 105-d-old rats to clarify whether or not age-dependent differences in pharmacokinetics and nephrotoxicity of Al exist. Using kidney function tests distinct signs of alumina (Al) nephrotoxicity can be demonstrated following 1 or 2 mg Al/100 g b. wt. i.p.: polyruria, reduced concentration of sodium in urine, elevated blood urea nitrogen concentrations. There is the same degree of nephrotoxicity both in adult and in young rats with an immature kidney function. Following administration of 2 mg Al/100 g b. wt. i. p. the initial plasma concentration of Al is distinctly lower in young than in adult rats. A rapid phase of elimination of Al from plasma (alpha-slope) is absent in 5-d-old rats and fully expressed in 33- and 55-d-old rats. In young rats the relative volume of distribution of Al is smaller than in adults. Following the administered dose nephrotoxicity in ducing concentrations of Al were obviously reached also in kidney tissue of young rats.

Aging↗
PubMed1986

[Desferal treatment of aluminum poisoning; effect on serum concentrations of aluminum (Al), iron (Fe) and copper (Cu)].

In 2 patients with a progressive dialysis encephalopathy and increased serum aluminium concentrations a Desferal-treatment with 500 mg per week was performed and in these cases the kinetics of Al, Fe, Cu was investigated. After the application of Desferal an increase of the serum levels, the ultrafiltrable proportion, the dialysance and the eliminated quantity of aluminium developed. In the course of the treatment in the two patients the aluminium level could be reduced to approximately normal values. Nevertheless one patient died of a severe course of a progressive dialysis encephalopathy. An increase of the copper concentration independent of Desferal-treatment after the dialysator passage remained without influence on the course of concentration of the serum copper in the examination period. A remarkable effect of the Desferal-therapy on the iron metabolism could not be established. Since in the dosage used there did not appear any side effects the Desferal-application is to characterized as a distinct and effective technique for the decrease of the serum-aluminium-concentration in patients undergoing dialysis.

Adult↗
PubMed1985

[Effect of Visotrast (R) and bilirubin on lipase and alpha-amylase activities of pancreatic secretions].

The contamination of pancreatic juice obtained by endoscopic retrograde catheterism of the papilla by cannulation of the pancreatic duct with contrast medium is possible. When the amount of "VisotrastR 370" is more then 0.05 ml per ml one observes a decrease of the lipase while alpha-amylase is unchanged.--Bilirubin has also an influence on the activity of lipase - but not on the alpha-amylase.

Bilirubin↗