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Biomedical subjects

W Romen

Publications and source records attributed to W Romen.

At least 37 records · Page 2Linked to original sources
PubMed1984

Carcinogenicity of dichloroacetylene: an inhalation study.

Dichloroacetylene (DCA) is a by-product of the synthesis of certain chlorinated, aliphatic hydrocarbons (e.g., vinylidene chloride). In a long-term carcinogenicity inhalation study, groups of 30 male and 30 female rats and mice were exposed to DCA vapour under the following conditions: mice, group I: 9 p.p.m. 6 h/day, 1 day/week for 12 months; group II: 2 p.p.m. 6 h/day, 1 day/week for 18 months; group III: 2 p.p.m. 6 h/day, 2 days/week for 18 months; rats: 14 p.p.m. 6 h/day, 2 days/week for 18 months; controls: under identical conditions except for addition of DCA to breathing air. The most important result is a striking increase in the formation of kidney cystadenomas of the proximal tubuli in all DCA exposed animals. The median latency time of this tumor varied widely in both mice and rats. Renal cystic adenocarcinomas were found in statistically significant numbers in male mice. In addition to kidney tumors, the development of cystadenomas of the Harderian gland in mice and of liver cholangiomas in rats were highly significant findings. DCA failed to induce liver tumors in mice. Our results confirm that DCA possesses a high carcinogenic potential, pronounced organotropic properties and distinct species differences referring to the number and nature of the induced tumors. The risk associated with handling chlorinated aliphatic hydrocarbons is essentially increased by the decomposition product DCA.

Acetylene↗
PubMed1984

[Irreversible renal failure following minimal change nephrosis].

A boy developed a nephrotic syndrome at the age of two years, and remained steroid sensitive for twelve years. In this time more than twenty relapses occurred. Two renal biopsies showed minimal changes. Renal function was normal all along. At an age of 14 years he developed an irreversible renal failure. Since this time he remained dependent to dialysis. A third renal biopsy now shows a perimembranous glomerulonephritis with a diffuse interstitial fibrosis.

Acute Kidney Injury↗
PubMed1983

Computer analysis of chromatin arrangement and nuclear texture in follicular thyroid tumours.

The differentiation of the thyroid glands follicular neoplasias into adenomas and carcinomas is currently done using the histological criteria recommended by WHO. This pilot study of 10 human follicular carcinomas and 10 folliculars adenomas demonstrates the possibility of a cytological classification using digital picture processing of high resolution cell images. Giemsa stained paraplast sections were scanned with a Colour-TV-camera, different channels were used with respect to staining and analyzing methods and computed with an image processing system. The computer aided cytophotometric methods detected significant differences in the chromatin arrangement and structure.

Adenocarcinoma↗
PubMed1983

The role of partial hepatectomy and of promoters in the formation of tumors in non-target tissues of trans-4-acetylaminostilbene in rats.

After repeated administration of trans-4-acetylaminostilbene to rats, DNA-bound metabolites accumulate to the greatest extent in liver and kidney, which are considered to be nontarget tissues for this carcinogen. To test whether the persistent DNA adducts represent procarcinogenic lesions, an initiation-promotion experiment was carried out using trans-4-acetylaminostilbene as an initiator and phenobarbital, DDT and diethylstilbestrol as promoters. In addition, partial hepatectomy was performed in some groups. Partial hepatectomy alone or in combination with promoters led to the formation of preneoplastic enzyme deficient foci, hyperplastic nodules and hepatoma in great yields. In addition, mammary tumors were observed with diethylstilbestrol promotion. The results support our proposal that aminostilbene derivatives produce procarcinogenic DNA-lesions in many, if not all, tissues and that secondary factors determine when and where tumors arise.

Adenoma, Bile Duct↗
PubMed1983

Functional anatomic reconstruction of the cardia.

Experiments on bastard dogs have shown that cardia reconstruction using an omega sling is effective. This sling is a pedicled, extramucosally excised, longitudinal muscle flap from the ventral aspect of the greater gastric curvature, which is prestretched at least 100%, wrapped around the cardia twice and sutured to the posterior gastric wall. A physiological pressure gradient is created with the help of intraoperative manometry. Perfusion manometry, radiology, histology and microangiographs demonstrate the competence of the omega sling.

Animals↗
PubMed1983

Human embryonal cell carcinoma in nude mice.

A lymph node metastasis specimen from a human testicular embryonal carcinoma with elements of a choriocarcinoma was successfully xenotransplanted into nude mice and maintained until the tenth animal passage. Electron microscopy of the tumors in nude mice revealed details consistent with their epithelial origin. The xenotransplants retained the ability to synthesize human choriogonadotropic hormone during all animal passages, as evidenced by radioimmunoassay and immunoperoxidase staining techniques. The beta-human choriogonadotrophic hormone serum level correlated significantly with the tumor volume (p less than 0.05). The average amount of beta-human choriogonadotropic hormone measured in the serum of 94 animals was 587.8 ng/ml, ranging from 5 to 4000 ng/ml. The chromosomal analysis of tumors in nude mice revealed a human chromosomal pattern with modal numbers between 55 and 60 chromosomes, and a consistent trisomy of chromosome 1.

Animals↗
PubMed1982

Autoradiographic studies on the proliferation of glomerular and tubular cells of the rat kidney in early diabetes.

Although Osterby and coworkers have shown that the onset of diabetes is associated with glomerular hypertrophy and enlargement of the filtration surface, the pathogenesis of this lesion and the behaviour of the glomerular tuft cells during the increase in glomerular filtration surface area remain unclear. Autoradiography and electron microscopic morphometry in kidneys of male Sprague-Dawley rats with streptozotocin-induced diabetes indicate that glomerular enlargement is combined with glomerular cell hyperplasia. 6 days after continuous 3H-thymidine infusion there is a significant increase in DNA-synthesis in tuft cells indicating cell proliferation. Since podocyte volume only increases in acute diabetes (as shown by Osterby and Gundersen in 1980), and the mean podocyte nuclear area remains unchanged, we conclude that the increased DNA-synthesis results in podocyte hypercellularity so that an increased glomerular filtration surface area can be covered by a greater number of cells.

Animals↗
PubMed1982

[Morphological changes after permanent nerve block by freezing and ethanol injection of the sciatic nerve of the rabbit (author's transl)].

Permanent nerve blocks by intraneurally injected alcohol are often complicated by alcohol-neuritis. Encouraging clinical experiences with permanent blocks by freezing raises the question whether morphological differences between the nerve lesions could explain the difference in their side effects. On 30 rabbits both sciatic nerves were blocked after surgical preparation. The one by intraneural injection of 0,5 ml of 96% Ethanol, the other by freezing with a cryoprobe. The resulting degeneration and the beginning of recovery of the nerves was followed by histological evaluations of the sciatic nerves during the first 28 days after the blockade. The nerve lesions of both types of blockade were complete. That produced by the cryoprobe was limited to the small area of local freezing, whereas the alcohol-block produced the same type of nerve degeneration but with a wide-spread extension reaching the sacral plexus. We discuss whether this slight morphological difference might be sufficient to explain the higher complication rate of alcohol blocks.

Animals↗
PubMed1982

[Microangiographic studies on the revascularization of free smooth muscle grafts].

The aim of the investigations was to find out exactly how and when revascularization of free transplanted smooth muscle took place. For this purpose a continent colostomy was performed on 15 dogs by sphincter plastics with a free autologous transplant. The dogs were killed between postoperative day 1 and 5, and their blood vessels were perfused with mixture of Indian ink and Ringers solution. The microangiographic observations of the microscopic section showed the following results. On postoperative day 1 at the edge of the transplant the vessels of the intestinal serosa were distinctly seen to have ellipsoid dilatation. On day 2 tiny filamentary branches of the vessels proliferated into the transplant and connected with the original vessels of the sphincter plastic. By days 4 and 5 this process was apparent.

Angiography↗
PubMed1981

Studies on collagen metabolism in rats. I. Age-related changes in turnover and amino acid composition of the collagen of glomerular basement membrane and tail tendon.

To examine the effect of age on the collagen metabolism of glomerular basement membrane (GBM) and tail tendon, both structures were labeled in vivo by the injection of tracer amounts of radioactive proline. The analyses of the labeled proline and, especially, hydroxyproline revealed that synthesis and degradation are reduced in senescent rats. The calculated turnover rate for GBM-collagen is prolonged by about 40% with increased life span. The reduced catabolism is responsible for the age-related thickening of the GBM. In addition, compositional analyses of isolated GBM and tail tendon were performed. Substantial age changes were observed in the amino acid composition of both structures. The hydroxylated amino acids showed a progressive increase with age, while proline and lysine were found to decline.

Age Factors↗
PubMed1981

Studies on collagen metabolism in rats. II. Turnover and amino acid composition of the collagen of glomerular basement membrane in diabetes mellitus.

The effects of streptozotocin diabetes on the collagen metabolism in rat glomerular basement membrane (GBM) have been investigated. The metabolic activity was measured in vivo by following the incorporation of 3H-proline into hydroxyproline over the course of 3 months. Under diabetic conditions, smaller amounts of labeled hydroxyproline were found in the GBM indicating that collagen synthesis is injured. The retarded disappearance of the tracer from the GBM is related to an additional alteration of the degradation resulting in a slower turnover. If collagen formation is reduced in streptozotocin diabetes, the thickening of the diabetic basement membranes can only explained by this disturbed catabolism. The amino acid composition of GBM was also altered after streptozotocin application. The diabetic animals showed an increase of hydroxylysine in this structure. The diabetic effects on the GBM presented were interpreted as a kind of accelerated aging of collagen.

Amino Acids↗