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Biomedical subjects

W Seffner

Publications and source records attributed to W Seffner.

At least 19 recordsLinked to original sources
PubMed2000

Studies on the influence of a Se-restricted diet on the effects of long-term increased copper intake in guinea pigs.

Guinea pigs were exposed to Se-restriction/deficiency in combination with drinking water containing 200 or 300 mg Cu/l for 6-30 weeks. Under the influence of Se-restriction/deficiency Cu excretion by bile was diminished, the Cu content of the kidneys was increased and disturbances of liver function were seen in animals exposed for prolonged periods. Some parameters of the immune system, such as the phagocytic activity of peritoneal macrophages, mitogenicity of spleen lymphocytes and the amount of lymphatic spleen tissue were also adversely affected. These effects correlated in part with the liver damage and the copper content of the kidneys. Conclusion are drawn with respect to the Idiopathic Copper Toxicosis/Indian Childhood Cirrhosis.

Animals↗
PubMed1998

Liver fibrosis in guinea pigs experimentally induced by combined copper and aflatoxin application.

Aflatoxin B1 alone (0.05 mg resp. 0.037 mg/kg/d), copper alone (6.6 mg/kg/d or 200 mg/l drinking water) or a combination of both was administrated orally for 6 months to young guinea pigs from the first/second day of life. In the copper group there were no pathomorphological changes. For the aflatoxin B1 group liver damage was established. In the combined group liver injury was more frequent and more severe compared to the aflatoxin B1 group. Compared with the copper group biliary copper excretion was diminished and the kidney copper content was elevated in the Afl. B1 + Cu group. While copper concentrations in bile and kidney correlated with other parameters, notably the pathological lesions of the liver, no such correlation was found for liver copper. Therefore in this experiment the degree of Cu accumulation was not decisive for the liver lesions. The livers' capacity for excreting Cu by bile seems to be a much more important factor. Histologically only the livers of the combined group exhibited degeneration, atrophy and steatosis of liver cells, and a fibrosis more or less pronounced. For childhood cirrhosis (ICC and ICT), a combined etiology--a liver damaging agent plus elevated alimentary copper--is a plausible hypothesis.

Aflatoxin B1↗
PubMed1997

Experimental induction of liver fibrosis in young guinea pigs by combined application of copper sulphate and aflatoxin B1.

Aflatoxin B1 alone (0.05 mg resp. 0.037 mg/kg/d), copper alone (6.6 mg/kg/d or 200 mg/l drinking water) or a combination of both was administered orally for 6 months to young guinea pigs from the first/second day of life. In the copper group there were no pathomorphological changes. For the aflatoxin B1 group, liver damage was established. In the combined group, liver injury was more frequent and more severe compared to the aflatoxin B1 group and biliary copper excretion was diminished compared with the copper group. Histologically, only the livers of this group exhibited degeneration, atrophy and steatosis of liver cells, inflammatory processes and a more or less prominent fibrosis. For childhood cirrhosis (ICC and ICT) a combined etiology--a liver damaging agent plus elevated alimentary copper--is a plausible hypothesis.

Aflatoxin B1↗
PubMed1995

Subchronic application of humic acids and associated compounds provokes histological changes of goitre in the rat.

1. Different preparations of humic acids, a pyrogallol oxydation product (PYROP) and resorcinol were administered to male and female rats with the drinking water for 8 to 14 weeks. 2. By histometrical evaluation of the thyroid glands, an increase of the mean epithelial cell height of follicular epithelial cells was established in the 0.1% humic acid groups, 0.1% PYROP group and the 0.004% resorcinol groups. Females seemed to be more sensitive than males. Additionally, in some experiments, a decrease of the mean follicular diameter was found, which was the result of newly formed little follicles. The changes must be considered as a precursor of goitre. 3. In one of the experiments, in which circulating thyroid hormones were investigated, the serum thyroxine level in the male 0.1% humic acid group and the free thyroxine index in the female 0.1% humic group were diminished as compared to the control groups.

Animals↗
PubMed1995

[Natural water contents and endemic goiter--a review].

A review is given of literature which considers water as the cause of endemic goitre irrespective of its iodine content and which incriminates goitrogenic substances in the water. There are evident connections between the geogenic origin of the water and the incidence of goitre insofar as water from shallow wells from phyllite, gneiss and slate was linked to an elevated goitre incidence as compared to water from igneous rock or from deeper wells with limestone underground. Water which caused goitre was often found to be grossly polluted. So far, nitrate, humic acids and some of their degradation products have been clearly identified to be goitrogenic. Experimental studies by the author emphasize the importance of nitrate as well as of humic acids and their derivatives as waterborne goitrogens.

Animals↗
PubMed1993

[Toasted rapeseed meal in broiler fattening diet].

A fattening trial of six week duration using male broiler chicks of the TETRA 82 genotype has been performed to evaluate the feeding value of rapeseed meal derived from the following rapeseed origins of so-called double-zero quality: Canola (Cananda), Jantar (Poland) and the new-bred East German-genotype BNW 1.43, each at a diet level of 12%. Moreover, the indigenous origin has been investigated at levels of 6 and 18% in practical broiler rations as a protein source instead of soybean meal (partial replacement). The fattening results (live weight development, intake and conversion of feed, mortality) do not show disadvantageous effects by the different rapeseed meal origins, and the various levels too. The chemical whole-body composition gives reduced fat and more protein in broiler's carcass at a diet level of 12 and 18% of BNW 1.43-rapeseed meal. Blood plasma levels of T3 and T4 have refered to beginning status of hypothyreodism, higher percentages of rapeseed mean had been fed. Weight of broiler's thyroid varied independtly of treatment. Also by the means of histometrical investigation of these glands the effects known for conventional rapeseed meals could be demonstrated, however in an important weakly extent. In comparison to discrepancies in the literature results regarding the possible inclusion of double-zero rapeseed meal in broiler diets, it seems a maximum diet level of 12% of toasted rapeseed meal of used qualities could be recommended for practical diet formulation (without of performance depressions). However, further investigations are be essential in these questions.

Animal Feed↗
PubMed1991

[Testing of extracted particles from winter rapeseed with different glucosinolate levels in swine with special reference to the iodine supply. 2. Thyroid hormone status, histomorphometric findings and iodine content of the thyroid gland].

In the experiment, 2 x 12 growing pigs received 19 or 6.7 mmol glucosinolates + aglucones/kg feed via conventional rapeseed meal (RSM) or RSM of a newly bred variety. These pigs and 24 littermates pair fed with a soya bean meal (SBM) diet were subdivided in groups of 4 animals each. Their diet contained either no supplementary iodine or an iodine supplementation of up to 1 mg/kg feed. In the RSM and SBM groups the lack of additional iodine lowered the serum T4 and T3 content below the detection limit and caused goitre with about 1 mg iodine in the total thyroid. The SBM diet with 0.0625 mg supplementary iodine/kg increased the serum T4 level and reversed the thyroid enlargement but not that of epithelial cells. The hypothyroidism (goitre and serum T4 level approximately 10 nmol/l) still existed in the case of this iodine dosage together with the RSM of the newly bred variety. A serum T4 level comparable to that of the animals fed SBM was only reached by supplementing the low glucosinolate diet with 0.25 mg iodine/kg feed. The iodine content of the thyroid, however, was reduced by 50 per cent. Though thyroid and epithelial cells were enlarged, this enlargement was not so obvious as in animals exposed to higher glucosinolate level. In spite of 1 mg supplementary iodine/kg feed, the feeding of the conventional RSM resulted in a lower serum T4 level a reduced thyroid iodine content and the enlargement of thyroid and that of epithelial cells. Compared to the high glucosinolate RSM, a significantly lower antithyroid effect of the low glucosinolate RSM was found in pigs with iodine supply. The degree of thyroid enlargement and the serum T4 level were the criteria.

Animal Feed↗
PubMed1990

Effect of varying glucosinolate and iodine intake via rapeseed meal diets on serum thyroid hormone level and total iodine in the thyroid in growing pigs.

In a trial with 50 fattening pigs (20 kg initial body weight), the effect of untreated rapeseed meal (RSM) (148 mmol glucosinolates and aglucones per kg dry matter) on the thyroid was compared with RSM treated with Cu2+ (9.5 mmol glucosinolates and aglucones per kg dry matter) and soybean meal (SBM). The diets containing 8% RSM were supplemented with 0.0625-1.0 and the SBM diet (control) with 0.125 mg iodine kg-1 (I). In comparison with SBM fed control, RSM treatment with Cu2+ resulted in a complete normalization of feed intake and growth. Only untreated RSM without I supplementation depressed performance and resulted in symptoms of I deficiency, but the thyroid and liver weight were also increased and the serum T4 content was significantly reduced in animals which were given RSM not supplemented with I, but treated with Cu2+. In young pigs (4 weeks) a plateau of the serum T4 content was achieved from 0.5 mg I kg-1 of the RSM diet onwards. In contrast, when the concentration of goitrogens was reduced by the treatment with Cu2+, the serum T4 level was increased significantly in groups fed with 0.125 mg I kg-1 diet and more. In older pigs (15 weeks) neither the content of goitrogens nor the I dosage affected the serum T4 level. On the other hand, the I content in the thyroid was a good indicator of the different goitrogenicity of the diet in the case of a low I supply. The present investigations show that pig diets with RSM (greater than 10 mmol glucosinolates and aglucones kg-1) should contain at least 0.5 mg I kg-1, but 0.1 mg supplementary I per kg is sufficient in diets without or with a low content (less than 1 mmol glucosinolates and aglucones per kg-1) of antithyroid compounds.

Animal Feed↗
PubMed1989

Histological and histometrical changes of liver damage in rats after treatment with ethanol and carbon tetrachloride.

A pretreatment of 30 to 52 weeks with a 10% (v/v) solution of ethanol did not bring about any distinct changes but increased the damaging effects on liver caused by an acute dose of carbon tetrachloride in rats. This was shown by the semiquantitative assessment of histological changes and by the measurement of hepatocyte nuclei. The results of both investigations are complementary to each other and show a correlation.

Alcoholism↗
PubMed1988

[Effects of nitrate and ascorbic acid on carcinogenesis in the operated rat stomach].

In the last few years, a great deal of attention has been paid to the hypothetical relationship between high nitrate intake, N-nitroso-compounds and gastric cancer. This long term study deals with the effect of nitrate and ascorbic acid contained in drinking water on the development of cancer in operated stomachs of rats without additional application of a carcinogen (tumor model). A total of 147 F1-Hybrids of WELS/Fohm X BD IX--rats were subjected to stomach operation (Gastroenterostomia antecolica anterior, truncular vagotomy and pyloroplasty). Carcinomas in stomach occurred within 33 weeks (post operationem). The surgical procedures altered the gastric flora, resulting in an increase and predominance of nitrate-reducing bacteria. The maximal tumor rate (10 of 13 rats) occurred in rats with gastroenterostomy and additional nitrate exposition. It may be possible, the nitrate is a precursor of gastric carcinogenesis. But we could not give any significant evidence of this fact. The addition of ascorbic acid to the drinking water lead to a suppression of the development of tumors. Our experience with the tumor model "operated stomach" underline the multifactorial genesis of stomach cancer in rats.

Animals↗
PubMed1985

[Vitamin A requirements of growing swine. 3. Effect of vitamin A supply on the state of health of piglets and fattening swine].

Diseases and losses were registered in dependence on vitamin A supply with 2,035 pigs (6.5-114 kg live weight). The histologic examinations comprised various organs of 72 animals. The content of the main protein fractions as well as antibody titre after supplementing antigenes were determined in the serum of 104 animals. The feeding of a vitamin-A- and carotinefree casein-starch-respectively a Vitamin-A-free cereal-soybeanmeal-diet led to deficiency symptoms after 7-8 respectively 16-19 weeks of experiment particularly in the shape of nervous disturbances and voice affectations. Histologically a hyperplasia and a metaplasia of the epithelium of the big ducts in the salivory gland could be proved. The repletion of a part of the avitaminotic animals by means of oral (500 I.U./kg feed) and parenteral (500,000 to 1,000,000 I.U. i.m.) vitamin A administration is proof of a lack of vitamin A. Vitamin A and provitamin dosage did not influence diseases and losses with the exception of the occurrence of deficiency symptoms. The protein content of the serum as well as that of the globulin fractions alpha, beta, gamma did not change, the albumin content was lower in the groups without vitamin A (p greater than 0.05). Antibody titre against the lipopolysaccharide of salmonella dublin and human gamma globulin were diminished in piglets and fattening pigs fed vitamin A free (p less than 0.05). Taking the criterion of animal health, a vitamin A requirement higher than for growth (250 I.U./kg feed) cannot be derived.

Age Factors↗