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Biomedical subjects

K Richter

Publications and source records attributed to K Richter.

At least 307 records · Page 17Linked to original sources
PubMed1984

The influence of cyclobarbital and diazepam on drug metabolism in vitro and their binding to cytochrome P-450.

Cyclobarbital inhibited diazepam metabolism by rat liver supernatant only at concentrations of 1 mM. Ethylmorphine N-demethylation is strongly inhibited by diazepam in a non-competitive manner whereas cyclobarbital shows a competitive inhibition type. Both cyclobarbital and oxazepam are weak inhibitors. Hexobarbital- evokes typical type I spectral changes with rat liver microsomes whereas cyclobarbital and diazepam-induced spectral changes are similar to type II or inverse type I. Barbital evoked the same type of spectral changes as diazepam and cyclobarbital. With the usual concentration in vivo the metabolism of diazepam and other drugs can scarcely be influenced by cyclobarbital.

Animals↗
PubMed1984

[Diagnosis and clinical course of cerebral hemorrhage in infants based on sonography].

Infants of very low birth weights (less than 1500 g) born before the 32nd week of gestation have a high incidence of neonatal intracranial hemorrhage (ICH). Beside perinatal and postnatal asphyxia the main risk factor for ICH is the immaturity of the infant. Mild intracranial hemorrhages resolve within a few weeks. Severe ICH, which were seen in very immature babies before 30 weeks of gestation and with birth-weights below 1250 g had a fatal outcome. The mortality rate in severe ICH was 50%. The infants which survived severe ICH developed posthemorrhagic hydrocephalus (PHH). Using the open fontanelle as an acoustic window gray scale ultrasonography of children's brain is able to visualize ICH and PHH. We suggest early sonografic brain investigation within the first days of life in all prematurely born infants with perinatal asphyxia. Infants with severe ICH should have weekly sonografic controls, to detect PHH as soon as possible.

Age Factors↗
PubMed1983

A novel peptide designated PYLa and its precursor as predicted from cloned mRNA of Xenopus laevis skin.

A variety of peptides closely related to mammalian hormones and neurotransmitters are secreted from amphibian skin. Using cDNA clones of mRNA isolated from skin of Xenopus laevis, we have been searching for precursors of some of these constituents. Here we present the sequences of parts of cloned mRNAs which code for precursors of a novel peptide. In the predicted polypeptides, pairs of basic residues flank a sequence of 25 amino acids terminating with glycine, the signal for the formation of a terminal amide. The predicted final product liberated from these precursors would be a peptide comprised of 24 amino acids starting with tyrosine and ending with leucine amide, which has therefore been designated PYLa. This peptide can form an amphipathic helix similar to that found in peptides with cytotoxic, bacteriostatic and/or lytic properties.

Amino Acid Sequence↗
PubMed1983

[Caesarean hysterectomy or tubal coagulation following caesarean section--a comparison].

From 1973 to 1982 a total of 99 Caesarean hysterectomies and 105 Caesarean sections with subsequent tubal coagulation were performed. This represents 6.5% and 6.9%, respectively, of all Caesarean sections. After excluding the emergency cases, 86 planned Caesarean hysterectomies and 99 Caesarean sections combined with tubal coagulation remained. Statistical evaluation showed that the postoperative course was more favourable and less febrile with Caesarean hysterectomy than with tubal coagulation after Caesarean section. The somewhat greater loss of blood after hysterectomy is practically without any sequel. Hysterectomy saves the patient from subsequent uterine diseases, ascending infections, menstrual anaemias, problems of hygiene, etc. Caesarean hysterectomy appears to be the method of choice if surgical sterilisation is deemed appropriate besides performing the Caesarean section; if the patient has been informed of the operation in detail; if the patient feels no emotional ties towards the uterus; if there has been ample opportunity to think things over calmly; and if the surgeon is really skilled in performing hysterectomy.

Cesarean Section↗
PubMed1982

[Transient chronic hepatitis after acute viral hepatitis A (author's transl)].

Serologic, chemical and in part bioptic follow-up investigations were done in 25 patients with acute viral hepatitis A. The disease course was completely uncomplicated in 19 patients; pathologically increased transaminases returned to normal within 3 months. Transaminases remained increased pathologically in 3 patients for 3 to 6 months. In a further 3 patients normalisation took 8 to 15 months. Two patients showed histologic changes in the early phase of the disease which were compatible with persistent or chronic active hepatitis. Cure of hepatitis appeared likely in all cases on the grounds of clinical and laboratory follow-up investigations. These investigations show that in acute viral hepatitis A prolonged disease courses and transient chronicity may occur besides the uncomplicated course.

Adult↗
PubMed1982

Decreased serum carnitine in valproate induced Reye syndrome.

A 3-year-old girl developed acute liver disease after treatment with valproate for 6 months. She developed the typical features of Reye syndrome. Serum free carnitine was decreased as well as 3-keto-valproic acid, the main metabolite of beta-oxidation of valproate. The serum valproate concentration was at the upper limit of the therapeutic range. The possible importance of carnitine in the pathogenesis of valproate induced liver disease is discussed.

Carnitine↗
PubMed1982

[An analysis of the diagnostic information derived from screening as against films during radiological examination of the stomach (author's transl)].

The value of screening procedures (with image intensifiers and television monitor) was compared with films during the radiological examination of the stomach, using a double contrast method. In one experiment, the diagnostic accuracy of experienced radiologists using screening only was compared with standardised films. There was a definite improvement using films. The reason for this was not the difference in the technical excellence of the images, but depended on the cognitive processes which lead the doctor to a diagnosis. For this purpose, static pictures provide a better basis than dynamic, rapidly changing and brief views seen during screening. The results lead to certain considerations concerning the methods for the radiological examination of the stomach.

Diverticulum↗
PubMed1982

Experimental evidence for an "internal leak" of cat gastric mucosa after stimulation with histamine and carbachol.

Numerous factors are involved in the pathogenesis of gastric ulcer. Possibilities under discussion are acid back diffusion, a reduction in the quality of the gastric mucus, and vascular factors that give rise to local ischemia. One hypothetical model presented for consideration, is based on the notion of an "internal leak", as a result of which acid escapes out of the parietal cells directly into the interstitium. Using the cationic dye acridine orange in cats, it has been possible to show, in particular after prior stimulation with stimulation with histamine and carbachol, but not with pentagastrin, that a microfocal accumulation of the dye in the interstitium can indeed be found. Under conditions of hypoxia, this phenomenon was not observed. In view of the specific properties of the dye, it may be concluded that, under certain conditions, acid substances can indeed diffuse out of the parietal cells into the interstitium. this animal model offers distinct findings compatible with the pathogenetic concept of an "internal leak".

Acridine Orange↗