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Biomedical subjects

W Arnold

Publications and source records attributed to W Arnold.

At least 397 records · Page 22Linked to original sources
PubMed1979

Biological characterization of a mesothelioma line in the nude mice. II. Some characteristics of cells cultivated in vitro prior to and after transplantation in nude mice.

Ascitic tumor cells from a female patient with a peritoneal carcinomatosis have been cultivated in vitro. The 25th in vitro passage of these cells were characterized by gowth curves. DNA-distribution patterns, chromosome patterns and drug sensitivity. Cells of the 25th in vitro passage were i.p. transplanted in nude mice. The 14th and 18th passage of ascitic cells and the 3rd passage of the solid tumor material grown in nude mice were compared with cells of the 25th in vitro passage. Changes in DNA-distribution patterns, chromosome patterns and drug sensitivity were observed: The G1/0-peak of the ascitic tumor cells (AP 14, AP 18) revealed a shift to the left. This is in coincidence with the chromosome number reduction found. Differences in sensitivity to Methotrexate and 5-Fluorouracil after transplantation in nude mice were observed. The possible reasons of instability of these biological properties are discussed.

Animals↗
PubMed1979

Demonstration and partial characterization of 22-nm HBsAg and Dane particles of subtype HBsAg/ady.

The present paper describes the demonstration of d, y, w, and r HBsAg determinants in one serum. It was shown that there are two populations of HBsAg particles: HBsAg/ad and HBsAg/ady. All complete Dane particles were of subtype HBsAg/ady. Further characterization of HBsAg/ady particles did not reveal morphologic differences when they were compared with HBsAg/ad and HBsAg/ay particles. An HBsAg/ady phenotype may be the result of a double infection with hepatitis B viruses or exchanges of DNA sequences that determine HBsAg/ay and HBsAg/ad to form a new genotype.

Adult↗
PubMed1978

[Electrode model for multiaxonal stimulation of the acoustic nerve (author's transl)].

An electrode arrangement is described, which allows an isolated stimulation of 25--50 singular axons: By laser beams a small ceramic plate got 25--50 perforations through which glass isolated platin wires were so fixed that they end like a brush. Only the tips of the "hairs" are not isolated. The diameter of the electrodes is approximately 10 micrometer, the length ranges between 0,5 and 1,5 mm. This electrode system is enough stabile to be pressed into a hard boiled egg without being damaged.

Acoustic Stimulation↗
PubMed1978

[Oxygen supply of middle- and inner ear in experimental tubar occlusion (author's transl)].

1. The mucosa of the middle ear is not only supplied with oxygen from the blood but also from the air space of the middle ear. 2. Under physiological conditions, the perilymph is supplied partially with oxygen from the tympanic cavity. When the PO2 in the middle ear falls below 57 mm Hg, a net diffusion flux of oxygen from the perilymph to the middle ear induces a loss of oxygen from the inner ear. 3. A negative pressure of 25 mm Hg generated in the middle ear, causes a transudate. Subsequently, slight disturbances of microcirculation should occur in the mucosal membrane (pO2-histogram). More pronounced negative pressure lead to very distinct disturbances of microcirculation and local oxygen supply.

Animals↗
PubMed1978

Electron microscopic findings in four cases of nasopharyngeal fibroma.

Light and electron microscopic investigations of four cases of juvenile nasopharyngeal fibroma revealed characteristic structures; a fibrous stroma, an inclination to hyalinisation and formation of scar like tissue, a lacunar thin walled vascular component, large numbers of mast cells and of fibroblasts. The tumor fibroblasts contained different nuclear bodies and particles. There existed five different types of more or less complex spherical bodies. The previously described nuclear electron dense particles with an electron lucent halo could be divided into four groups measuring 60, 90, 150, and 300 nm in diameter. In addition to the previously described ultrastructural properties of the tumors, the nuclei of the tumor fibroblasts were found to contain virus like particles. These particles were less electron dense, measuring 40 to 55 nm in diameter and arranged in groups throughout the nucleoplasm; they were different from chromatin condensations and from perichromatin granules. The structure and the size of the smallest particles was not comparable with the other nuclear inclusions.

Adolescent↗
PubMed1978

[Light and electron microscopic studies of the greater epithelial ridge and its relationship to the developing tectorial membrane in the cochlear duct of the guinea pig (author's transl)].

In early stages of fetal development (36th day, 3rd turn) the thickening of the epithelium at the basal side of the cochlear duct forms two ridges. Later in fetal development the laterally situated lesser epithelial ridge forms the major part of the organ of Corti, whereas the medially situated greater epithelial ridge contributes only a small part to this organ. The medial part of the greater ridge consists of the columnar inner supporting cells, which bear a border of closely packed microvilli at their upper surface. Up to the time of the opening of the internal spiral sulcus in the 48th day of fetal development, there is a close spacial relationship between microvilli and filaments of the tectorial membrane. We conclude that the inner supporting cells contribute to the formation of the tectorial membrane. However, thus far we cannot entirely exclude a different possibility, that the inner supporting cells absorb material of the tectorial membrane. During the opening of the sulcus spiralis internus the inner supporting cells become considerably smaller, some of them undergo complete destruction by cytolysis, with pyknosis and karyorrhexis.

Animals↗
PubMed1978

Anti-HBc, HBeAg and DNApolymerase activity in healthy HBsAg carriers and patients with inflammatory liver diseases.

In this paper we report on anti-HBc-titers, HBcAg, DNApolymerase activity in the serum and intracellular HBsAg in healthy HBsAg-carriers and patients with HBsAg-positive inflammatory liver diseases. 32/44 patients with acure virus-B-hepatitis were negative for anti-HBc in the first week of the disease. Anti-HBc-titers in healthy HBsAg-carriers varied between 1:10 and 1:32,000 (medium titer 1:4,000). In HBsAg-positive CAH we found a medium titer between 1:32,000 and 1:64,000, in cases with CPH of about 1:16,000. All autoimmune type CAH showed anti-HBc-titers less than 1:10. By immunofluorescence we could demonstrate in a group of 71 asymptomatic HBsAg-carriers in none of the healthy HBsAg-carriers HBcAg in the liver cell nuclei. In contrast HBcAg could only be found in 4/5 HBsAg positive CAH- and 6/9 CPH patients. No elevated DNApolymerase activity could be demonstrated in healthy HBsAg-carriers. Out of 44 patients with virus-B-hepatitis only 3 showed elevated DNApolymerase activity. On the other hand DNApolymerase elevation was demonstrable in 17/37 cases with CAH and 9/15 with CPH. The investigations showed a strong correlation between the demonstration of HBcAg in the serum and the DNApolymerase activity. The characteristic findings enabled us to differentiate between "healthy" HBsAg-carriers and HBsAg-carriers with inflammatory liver diseases.

Alanine Transaminase↗
PubMed1978

[Functional morphology of stria vascularis after treatment with ethacrynic acid or atoxyl (author's transl)].

Surface alterations of the stria vascularis and Reissner's membrane were studied in guinea pigs following intravenous or intraperitoneal administration of ethacrynic acid or atoxyl. DC-potential was measured in the same animals during intoxication. In addition we studied changements in potassium concentration (perilymph, endolymph) of the atoxyl-treated animals.

Action Potentials↗
PubMed1978

[Morphology of nasopharyngeal fibroma (author's transl)].

Light and electron microscopic investigations of four cases with juvenile nasopharyngeal fibroma revealed the characteristic structures like a fibrous stroma, and inclination to hyalinisation and formation of scar like tissue, a lacunar thin walled vascular component, a high amount of mast cells, and of fibroblasts with different nuclear bodies and particles. The well known electron dense nuclear inclusions were subdivided into three groups of size. The tumor cell nuclei also contained five different types of more or less complex bodies with spherical shape. In addition to the earlier described ultrastructural properties of the tumor the nuclei of the tumorous fibroblasts were found to contain virus like particles measuring 40 to 55 nm in diameter. These particles were aggregated to groups; they were different from chromatin condensations and from perichromatin granules. The structure and size of the smaller particles was not comparable to that of the electron dense nuclear inclusions regarded as pathognomonic in the nasopharynegal fibroma.

Adolescent↗
PubMed1978

[Circulating immune complexes in acute viral hepatitis, chronic active hepatitis, and periarteritis nodosa (author's transl)].

Circulating immune complexes were determined in patients with acute viral hepatitis, chronic active hepatitis and periarteriitis nodosa with the Raji cell technique. Circulating immune complexes were found in 11/18 HBsAg positive and HBsAg negative cases of acute viral hepatitis. In HBsAg positive chronic active hepatitis immune complexes were detectable in 42/43 cases but only in 1/27 HBsAg negative cases. Ten healthy HBsAg carriers demonstrated no detectable immune complexes. Using FITC conjugated antisera against HBs, HBc, and e antigen, immune complexes could not be found in any case of acute viral hepatitis or chronic active hepatitis. Elution of immune complexes from Raji demonstrated IgG, C'3 and a lack of HBsAg, HBc or e antigen. Immune complexes were present in 4/8 cases with periarteriitis nodosa. Viral components were detectable in one case.

Acute Disease↗
PubMed1978

Experiments to increase the selectivity of tumor chemotherapy by means of in vivo activation of transport forms of cancerostatics by exogenous enzymes.

A significant tumor damaging effect (growth inhibition) on transplanted syngeneic sarcoma in mouse was obtained by means of pH-dependent activation of a transport form of a cancerostatic drug by an enzyme foreign to the organism. This effect was achieved by combined administration of 8-0-(alpha-L-arabinofuranosyl)beta-peltatin-A as a transport form of beta-peltatin-A and the exogenous enzyme alpha-L-arabinofuranosidase from Aspergillus niger and additional increase of the acidity of the tumor by injection of glucose. The combined application of the transport form plus enzyme showed a more favorable effect on selectivity than free peltatin when a quantitative comparison was made between the tumor growth inhibition and the damage to the blood picture.

Animals↗