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Biomedical subjects

R Krüger

Publications and source records attributed to R Krüger.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1982

[Prevention by metyrapone of halothane induced liver necrosis in rats (author's transl)].

Liver necrosis and an increase of serum sorbitol dehydrogenase activity can be produced in rats by halothane anesthesia (1% v/v in oxygen) following pretreatment with polychlorinated biphenyls. Using this model, it was shown that administration of metyrapone (2-methyl-1,2-bis(3-pyridyl)-1-propanone) (100 mg/kg b.w.) 1 h prior to anesthesia prevents liver necrosis and the concomitant increase in serum sorbitol dehydrogenase activity. No significant differences were observed when halothane was applied in air instead of oxygen, but the protective effect of metyrapone was abolished.

Animals↗
PubMed1980

[Castleman's lymphoma (author's transl)].

Intrathoracic angiofollicular lymph node hyperplasia (Castleman's lymphoma) was found in a 32-year-old woman. The diagnosis could be established already preoperatively by endoscopic biopsy. It was a coincidental discovery as there were no clinical symptoms. Histologically the tumour was of the hyaline-vascular type. After uncomplicated surgical removal follow-up at 6 weeks was unremarkable. Aetiology and pathology of this rare disease are unknown.

Adult↗