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Biomedical subjects

R Krüger

Publications and source records attributed to R Krüger.

At least 19 recordsLinked to original sources
PubMed1995

[Viewpoints].

Explore the source record for details and available documents.

Eligibility Determination↗
PubMed1990

[New battery-powered equipment for continuous measurement and monitoring of blood pressure and body temperature].

This study reviews two newly developed battery-powered monitors for the accurate and invasive measurement of arterial blood pressure and body temperature. Their way of functioning is described in detail. Both devices allow a close monitoring of blood pressure, pulse rate and body temperature and a suitable intervention during the transport of critically ill patients and organ donors. Both monitors have high accuracy and stability, simplicity of operation and are robust. They are also relatively small and light. In addition, the devices are very suitable for measurement not only in humans but also in small animals like rats. The temperature monitor shows high accuracy in a range from -20 to 100 degrees C and is well suited for momentary and continuous temperature measurement in many other fields of application.

Blood Pressure Monitors↗
PubMed1989

Kinetics of antipyrine and sulfamethazine in patients recovered from dihydralazine-hepatitis.

Pharmacokinetic studies with sulfamethazine (500 mg) and antipyrine (15 mg/kg) were performed in 27 hypertonic patients (16 females, 11 males, 37-78 years) who had recovered from a dihydralazine-induced hepatitis, and 21 patients with essential hypertension (13 females, 8 males, 18-74 years) treated with antihypertonics excluding dihydralazine. 20 patients of the hepatitis group (74%) and 12 patients of the control group (57%) were slow acetylators. With regard to the pharmacokinetic parameters no differences were found in both slow and rapid acetylators between the sulfamethazine group and the antipyrine group.

Acetylation↗
PubMed1986

Comparison of the metabolism of the three antidepressants amitriptyline, imipramine, and chlorimipramine in vitro in rat liver microsomes.

The metabolism of the tricyclic antidepressants amitriptyline (AMI), imipramine (IMI), chlorimipramine (CMI) and some of their metabolites was studied in vitro in isolated liver microsomes of female Spraque-Dawley rats. Nine metabolites of AMI, seven metabolites of IMI, and 11 metabolites of CMI were quantitatively determined with high-performance liquid chromatography. The main metabolic reactions, mediated by an NADPH generating system, were hydroxylation, demethylation, and N-oxidation. The ratio of these reactions was different for the three drugs. AMI was hydroxylated more than CMI and CMI more than IMI. The order for demethylation was CMI greater than AMI = IMI, the order for N-oxidation IMI greater than CMI less than or equal to AMI. The substrate dependence of metabolism was investigated. Demethylation and N-oxidation increased proportionally to increasing substrate concentrations, whereas formation of hydroxylated metabolites became saturated (in the concentration range of 10(-6)-10(-5) M). The in vitro metabolism was compared with the in vivo metabolism in humans, reflected by the plasma concentrations of these drugs and their metabolites. A good agreement in metabolic pathways was found.

Amitriptyline↗
PubMed1986

Influence of neuroleptics on the metabolism of tricyclic antidepressants--in vitro experiments with rat liver microsomes.

The influence of two neuroleptics--the phenothiazine perazine and the butyrophenone haloperidol--on the metabolism of the tricyclic antidepressants amitriptyline (AMI), imipramine (IMI), and chlorimipramine (CMI) was studied in vitro in isolated liver microsomes of female Sprague-Dawley rats. The rats were pretreated over 10 days with either NaCl solutions or with 1, 3, and 10 mg/kg haloperidol or 5 and 15 mg/kg perazine, respectively. The microsomal fraction was incubated with various concentrations of antidepressants. The drugs and their metabolites were analyzed by high-performance liquid chromatography (HPLC). Neither pretreatment with haloperidol nor perazine had any significant influence on the demethylation and N-oxidation activity of the microsomes. Benzylic 10-hydroxylation of AMI or IMI or 10- and 11-hydroxylation of CMI was inhibited significantly by pretreatment with perazine, as was 2-hydroxylation of IMI and CMI, whereas 8-hydroxylation of CMI was not influenced. The inhibition was dose dependent. With haloperidol, only the high dose of 10 mg/kg caused a significant inhibition of benzylic 10-hydroxylation, whereas phenolic hydroxylation was not influenced. The inhibition was much lower than for perazine. Comparing the results with pharmacokinetic studies in humans revealed a good agreement in metabolic pathways. The study could therefore be important in the choice of neuroleptic drugs in combination therapy.

Amitriptyline↗
PubMed1984

Determination of benperidol in human plasma by high-performance liquid chromatography.

A high-performance liquid chromatographic method for the quantitative determination of benperidol in human plasma using haloperidol as internal standard is described. The method involves liquid-liquid extraction, separation of the substances on a reversed-phase column C18 followed by ultraviolet detection at 254 nm. The mobile phase consists of 32% acetonitrile in 0.05 M potassium dihydrogen phosphate buffer (pH 2.8). The detection limit is 0.5-1.0 ng/ml using 2- or 4-ml plasma samples.

Benperidol↗
PubMed1984

[Malignant blue nevus in Ota's nevus].

A 21-year-old Caucasian woman with congenital nevus of Ota developed a subcutaneous tumor below the lacrimal sack within the area of discoloration. The tumor, located subcutaneously, has been present for 4 years. Histologically, parts of the tumor showed neuroid structures as well as those like cellular blue nevus. In one part, however, malignant transformation features could be found.

Adult↗
PubMed1984

[Wegener's granulomatosis].

A case of an unusual development of Wegener's granulomatosis is described. A long-term immunosuppressive therapy led to intermittent involution of the process, but finally a transformation to a new disease, for present qualified as "malignant histiocytosis" was the result. The cause of the transformation and the differentiation from other necrotising granulomas are discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1982

Sex dimorphism of the adrenal cortex in rats after treatment with dexamethasone.

Sex dimorphism of adrenal cortex of the rat was studied by light and electron microscopy as well as the karyometric, gravimetric, and histometric methods after treatment with dexamethasone (2.0 mg/kg over a period of 4 days). Sex dimorphism cannot be shown in dexamethasone-induced atrophy of adrenal glands. Male fasciculata cells have more and finer distributed liposomes resembling in this way female fasciculata cells. Normally present differences in adrenal weight and nuclear size of fasciculata cells between both sexes disappear; nevertheless, female fasciculata cells remain relatively bigger compared to the corresponding male cells. Annulment of sex dimorphism is thought to be the result of altered functional activity of the zona fasciculata due to failing pituitary stimulation. Higher secretion activity of female fasciculata cells probably ceases after dexamethasone treatment.

Adrenal Cortex↗