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Biomedical subjects

R Dietrich

Publications and source records attributed to R Dietrich.

At least 55 records · Page 3Linked to original sources
PubMed1985

Intestinal ischemia caused by cocaine ingestion: report of two cases.

Ingested cocaine can be a cause of severe bowel ischemia or gangrene. Two cocaine addicts who ingested large quantities of the drug developed severe abdominal symptoms and signs caused by bowel ischemia. In one patient gangrene of the bowel necessitated repeated resections and was followed, several weeks later, by death. The other patient suffered less severe ischemia and the bowel returned to normal. The diagnosis of bowel ischemia should be suspected whenever a cocaine addict has severe abdominal symptoms and signs. The presence of marked leukocytosis suggests bowel gangrene and demands prompt surgical intervention.

Adult↗
PubMed1984

The cardiovascular effects of neuropeptide Y (NPY).

NPY (1ng-10/micrograms) had no effect on mean arterial pressure (MAP) or heart rate (HR) when administered into the lateral brain ventricle or cisterna magna of conscious, chronically instrumented normotensive, male Wistar rats. However upon intravenous injection (0.1-5/micrograms) it produced a dose related pressor response accompanied by bradycardia. This pressor effect was not influenced by prazosin infusion (100 micrograms/kg/min). These results suggest that NPY has no direct role in central cardiovascular regulation, but peripherally is a very potent vasoconstrictor peptide.

Animals↗
PubMed1982

Regulation by repression of urease biosynthesis in Proteus rettgeri.

Measuring the specific enzyme activity in cells of Proteus rettgeri it was shown that urease formation is controlled by repression through ammonia. Derepressed synthesis of the enzyme, as initiated by the absence of ammonia, required an external nitrogen source, which may not only be urea, but also nitrate, glutamate or nutrient broth. In contradiction to earlier reports the observations indicated that urea is not required for the synthesis of this enzyme, and that, therefore, urease is not an inducible enzyme in this microorganism.

Culture Media↗
PubMed1982

Small intestinal mucosa in coeliac disease and cow's milk protein intolerance: morphometric and immunofluorescent studies.

One hundred and twenty-five small intestinal biopsies from children with coeliac disease (CD), cow's milk protein intolerance (CMPI) and controls were compared by morphometric analysis, by counting intraepithelial lymphocytes (IEL) and by quantitative evaluation of immunoglobulin-containing cells of lamina propria. The double-stain immunofluorescent technique of Brandtzaeg and Baklien [2] was used, based on defined mucosal tissue units. A patchy enteropathy was found in 60% of CMPI, and in 14% of nonspecific changes, but never in CD. There was a significant difference in crypt depth between CD (360 +/- 80 microns) and CMPI (217 +/- 92 microns), even when lesions of equal grade were compared (P less than 0.015). IEL counts per 1000 epithelial cells showed even better discrimination between the groups (CD: 793 +/- 173, CMPI: 320 +/- 143, P less than 0.001). In CD, there was a relatively greater increase of IgM-cells (X 4.9) and of IgG-cells (X 4.2) than of IgA-cells (X 2.6). Ig-cell changes outlasted the morphological lesion in CD on a gluten-free diet. In CMPI, IgM-cells (X 2.3), IgG-cells (X 2.5), and IgA-cells (X 1.7) were proportionately increased, compared to controls. A special increase of IgE-cells in CMPI could not be substantiated. By computerized stepwise discriminant analysis based upon crypt depth, villus/crypt-ratio, IEL-count, and counts of IgM-, IgG-, IgA-containing cells of lamina propria, accurate classification of patient groups was accomplished, even when only the initial biopsy data were analysed.

Animals↗
PubMed1977

[Cerebrospinal toxoplasmosis: detection, clinical course and therapy].

With modern techniques (membrane marking by indirect immunofluorescence and identification by morphological criteria) Toxoplasma gondii can be reliably identified in the CSF. Identification of the causative agent confirms the diagnosis of toxoplasmosis of the meninges, the central nervous system and the nerve roots. Toxoplasma encephalomyelitis associated with meningoradiculitis has hitherto only rarely been described. Our own cases afford evidence of the fact that even in the most typical cases of multiple sclerosis this possibility must be considered. Fansidar (a combination of an ultralong-acting sulfonamide with pyrimethamine combined with spiramycine is recommended as the treatment of choice.

Adolescent↗
PubMed1977

In vitro culture of lymphocyte colonies in agar capillary tubes after PHA-stimulation.

Human peripheral lymphocytes were stimulated with phytohemagglutinin (PHA) in liquid culture, suspended in agar and incubated in glass capillary tubes. Compact colonies of lymphocytes were found growing along the tube bottom in a buffer film, while compact clusters and rare diffuse colonies were observed inside the agar. Several parameters affecting the clonal growth were studied and optimized: PHA-dose, agar concentration, gel length (volume), quantity and density of seeded cells per capillary and gel length. Colony yield mainly depends on the seeded-cell density with a sharp optimum at 2 X 10(5) cells/ml irrespective of gel length; higher cell densities reduce the colony yield, suggesting that colony growth is the result of both stimulatory and inhibitory factors produced by cooperating cells. Following the daily clonal growth was only possible with undisturbed tubes; the number of colonies steadily increased from day 2 until day 7. Densitometric colony scanning is possible, yet problematic. Colony yield (plating efficiency is 10--50-fold higher in agar capillaries than in the usual Petri dishes. An additional advantage is that the capillaries provide a basis for a simple and reliable assay system for determining regulatory factors of lymphocyte proliferation (including chalones).

Agar↗