Biomedical subjects

E Kolb

Publications and source records attributed to E Kolb.

At least 55 records · Page 3Linked to original sources

PubMed1992

[The content of Hb in the blood and of different constituents in the plasma of lambs with low and normal increase in body mass].

In lambs with a very restricted intake of nutrients and an increase of the body mass of less than 60 g per day (group A) and in those with an increase of more than 220 g/day (group B), analyses of components of the blood and the plasma were performed at certain intervals. In the lambs of group A an anemia developed in the course of 77 days. The concentrations of alpha-amino-N, non-protein-N, urea, glucose and insulin as well as the activity of the alkaline phosphatase of the plasma of the lambs of group A were always lower than those of group B. The beta-hydroxybutyrate concentration of the lambs of group A on the 7th and 21st day of the experiment was higher than that of group B. The concentrations of inorganic phosphate and iron in the plasma of group A at most points during the study were lower than that in group B.

Amino Acids↗

PubMed1991

[The content of beta-carotene, vitamin A and ascorbic acid in different tissues of bulls, short-scrotum bulls and oxen of different body weights].

Analyses of the liver of bulls of different age show, that the concentration of beta-carotene in the age of 6 to that of 25 weeks increased only from 0.43 +/- 0.16 to 1.66 +/- 0.27 and that of vitamin A from 11.49 +/- 5.87 to 13.90 +/- 5.21 micrograms/g fresh weight. The concentration of beta-carotene and of vitamin A in the testis of bulls and of short scrotum bulls up to an age of 15 weeks was similar; thereafter the concentration in the short scrotum bulls was higher. At an age of 72 weeks the concentration of vitamin A in the liver of bulls (219.17 +/- 51.86) was higher (p less than 0.01) than in that of the short scrotum bulls (144.11 +/- 27.79) and that of the oxen (135.51 +/- 41.26 micrograms/g fresh weight). Analyses of the concentration of ascorbic acid in 8 different tissues of bulls and short scrotum bulls at 6 various periods show, that the highest values mostly were found in December.

Animals↗

PubMed1991

[Content of beta-carotene, vitamin E and ascorbic acid in blood plasma of female calves, cattle, bulls, castrates and ox throughout the course of the year].

The concentration of beta-carotin, of vitamin E and of ascorbic acid in the plasma of female calves (beginning with an age of 4 weeks), of cows in the 2nd and 5th lactation, of bulls, of short scrotum bulls and of oxes in the course of the year was analysed. The concentration of beta-carotin in the plasma of calves after driving up to pasture increased slower than that of cows. After transition to stable feeding there was a significant decrease in the concentration after 4 weeks. During the period of suckling the concentration of vitamin E in the plasma of calves was low. After transition to pasture the concentration of vitamin E in the plasma of calves increased slower than in that of the cows. The concentration of ascorbic acid in the plasma during the winter was higher than during the summer. There was no influence of experimental cryptorchism or castration on the mentioned values.

Aging↗

PubMed1991

[The content of minerals and Fe, Cu and Zn in blood plasma, in erythrocytes and in 10 different tissues of bulls, short scrotum bulls and oxen].

The concentrations of minerals (Ca, Mg, Na, K, total-P) and of trace elements (Fe, Cu, Zn) in the plasma and erythrocytes of bulls, of experimentally induced cryptorchids (Muchsen) and of oxen of the breed Holstein-Friesian and of bulls and cryptorchids of a hybrid breed with a high portion of meat-cattle were investigated. Further the concentrations in various tissues (M. semimembranosus, M. longissimus dorsi, left and right ventricle, liver, kidney, adrenal glands, lung, spleen, testis) in bulls, cryptorchids and oxen of the breed Holstein-Friesian were analyzed. The differences of some concentrations of various elements in some tissues are discussed relative to their genesis and significance.

Animals↗

PubMed1991

Clonal deletion of V beta 14-bearing T cells in mice transgenic for mammary tumour virus.

Autoreactive T lymphocytes are clonally deleted during maturation in the thymus. Deletion of T cells expressing particular receptor V beta elements is controlled by poorly defined autosomal dominant genes. A gene has now been identified by expression of transgenes in mice which causes deletion of V beta 14+ T cells. The gene lies in the open reading frame of the long terminal repeat of the mouse mammary tumour virus.

Amino Acid Sequence↗

PubMed1991

[The effect of a different level of crude protein in the feed of chickens from 1 to 14 days after hatching on the development of body weight, the biochemical parameters of the liver and breast muscle and the serum level of total protein and albumin].

The effect of a concentration of crude protein of 170 or of 227 g/kg in the ration of chicken from the 1st to the 14th day after hatching on biochemical values of the liver, the M. pectoralis superficialis and the serum was analysed. The significance of developmental investigations in domestic animals under normal and pathological conditions is discussed.

Albumins↗

PubMed1991

[Current knowledge of the mechanism of neutrophil granulocyte and macrophage activation for the formation of superoxide anions and of H2O2 and for the causes of defects in the NADPH-oxidase enzyme system involved].

By the binding of activators (f.e. complement factor C5a, leukotriene B4) to receptors of neutrophil granulocytes an activation of a GTP-binding protein is induced, that increases the activity of the phospholipase C in the membrane and thereby the liberation of inositol-1,4,5-phosphate (IP) and of diacylglycerol (DG). The IP effects the liberation of Ca from intracellular stores and an increase in the concentration of Ca-ions in the cytosol. The DG induces an activation of the phosphokinase C near the membrane, that phosphorylates a cytosolic protein, which takes part in the formation of the NADPH-oxidase. The mentioned reactions induce in the membrane the construction of the NADPH-oxidase from a NADPH-binding protein, a flavoprotein, a cytochrome b 558 and from 4 cytosolic proteins. When phagolysosomes are formed, the NADPH-oxidase is part of the membrane, so bactericidal superoxide-anions can be introduced in these. In the chronic granulomatous disease defects in the formation of cytochrome b or of 2 cytosolic proteins exist.

Anions↗

PubMed1991

[Current knowledge of characteristics and effects of alpha and beta tumor necrosis factors (cachectins)].

The tumour necrosis factors (TNF) alpha and beta play a role in the activation of the immune system in bacterial and viral infections as well as in parasitoses and inflammatory processes, respectively. The TNF alpha is formed mainly by activated macrophages and mast cells, the TNF beta is formed by activated T- and B-lymphocytes. The evocation of necroses in certain forms of tumours is done by the furthering of the formation of activated O2-molecules (H2O2, peroxide anions, hydroxyl radicals). In tumour cells with a high activity of glutathione-peroxidase and of Mn peroxide-dismutase the TNF are without any effect. The TNF activate neutrophil and eosinophil granulocytes as well as macrophages. By induction of the formation of an oligoadenylate synthetase in virus-infected cells they inhibit the virus reproduction. In chronic infections and parasitoses they evoke a retrogression of the fatty tissue (cachexia). The division of fibroblasts is stimulated via the activation of the genes c-myc and c-fos. In the same way like interleukin 1 and interferon gamma they cause fever.

Adipose Tissue↗

PubMed1991

[Endothelins--properties, formation, mechanism of action and significance].

In endothelial cells of the blood vessels and in other cell types by the cleavage of precursor-molecules 21 amino acids containing peptides--the endothelins--are formed. There exist 3 isoforms. The synthesis of endothelin 1 in the endothelial cells is stimulated by adrenaline, noradrenaline, angiotensin II, arginine-vasopressin, thrombine, interleukin 1 and hypoxia. Receptors for endothelins are distributed in most tissues. A significance of the endothelins apparently exists in the stimulation of the activity of the heart and in the vasoconstriction in the case of a decrease of the blood pressure (when blood is lost) and of hypoxia. Endothelins are also formed in the lungs, the kidneys, the brain and the eye. In experimental animals already a low dose of endothelin has a lethal effect by inducing disturbances in the cardiovascular system. By the snake species Atractaspis engaddensis formed sarafotoxins have a similar structure as the endothelins and are effective by binding to their receptors.

Animals↗

PubMed1991

[Current knowledge on the formation of nitric oxide in endothelial cells of blood vessels, in nerve cells and macrophages as well as its significance in vascular dilatation, information transmission and damage of tumor cells].

The vasculature endothelium cells and the nerve cells of several regions of the brain and the autonomous nerve system contain a nitric oxide (NO)-synthase, that forms NO from arginine. The NO-synthase is stimulated by bradykinin, histamine and acetylcholine and is especially active in the coronary and brain vessels. In the vasculature smooth muscle NO activates the guanylate cyclase: The increase in the concentration of cGMP induces a relaxation and in this way a vasodilatation. In the nerve cells NO is active as a neuromodulator. The activation of macrophages by gamma-interferon or by lipopolysaccharides induces the formation of a NO-synthase, that has other properties than the enzyme of the endothelium cells. The macrophages secrete NO and inhibit the metabolism of tumour cells, especially enzymes of the respiratory chain and of the citric acid cycle as well as the DNA-synthesis. Trinitroglycerin and amyl nitrite form with thiol-compounds S-nitroso-compounds, the decomposition of these forms NO.

Amino Acid Oxidoreductases↗

PubMed1991

[The content of DNA, RNA and total protein in different skeletal muscles, in the diaphragm, in the right and left heart ventricles and in the musculature of the esophagus, the stomach and the urinary bladder of normally developed piglets and splayleg piglets of different body weights].

Studies were conducted into concentrations of RNA, DNA, and total protein in various skeletal muscles, diaphragm, right and left ventricles as well as in musculature of the oesophagus, stomach, and urinary bladder of 25 normally developed piglets and 24 sprayleg piglets of differentiated body weight (B.W.). DNA concentration was found to be at its highest in piglets of lowest B.W. The Protein: DNA-quotient increased along with growing B.W. The average value of this quotient in the anterior tibial muscle and brachial triceps muscle of sprayleg piglets was lower than that in normally developed piglets. Average values of the RNA:DNA quotients in the brachial triceps muscle, anterior section of the long dorsal muscle, left ventricle, and stomach muscles were also lower in sprayleg piglets. In newborn piglets, DNA concentrations in ventricles as well as in the muscles of the stomach and oesophagus were higher than those recordable from skeletal muscles. Causes of incapability of newborn piglets to stand on their own feet are discussed in some detail.

Animals↗

PubMed1991

[The concentration of ascorbic acid in different tissues of calf fetuses in 3 different development stages].

The concentration of ascorbic acid in the cerebrum and in the brain stem of bovine fetuses decreased with increasing body weight; in the cerebellum there was no change. The decrease of the concentration in the lungs, in the heart, in the kidneys, in the M. longissimus and in the M. semimembranosus in the course of the fetal growth was different. In the liver and in the adrenals the concentration in the 3 groups of fetuses with a body weight of 4.18 +/- 2.01, of 9.72 +/- 0.97 and of 17.12 +/- 2.61 kg was similar. The highest concentrations were found in the adrenals, in the testes and in the cerebrum. The functional significance of the changes in the concentration in the tissues of the bovine fetuses is discussed and compared with the results in human fetuses and in adult cattle.

Animals↗

PubMed1991

[Ascorbic acid concentration in plasma, in amniotic and allantoic fluids, in the placenta and in 13 tissues of sheep fetuses and newborn lambs].

At each 8 on an average 92 (body weight 615 +/- 49 g) and 120 days (b.w. 1.8 +/- 0.40 kg) old fetuses as well as at 6 newborn lambs (b.w. 2.8 +/- 0.65 kg) the concentration of ascorbic acid in the plasma, in the amniotic- and allantois-fluid, in the fetal and maternal part of the placenta and in 13 tissues was analyzed. The highest concentration in the plasma (73 +/- 11 micrograms/ml) was determined in the newborns. The concentration in the amniotic-fluid decreased and that in the allantoic-fluid, the adrenals and the fetal part of the placenta increased in the course of growth. In the cerebrum, the cerebellum, the brain stem, the lungs, the heart, the kidneys, the M. longissimus and the M. semimembranosus the concentration diminished during the fetal growth. In the liver, the spleen and the pancreas the concentration was similar. The function of the ascorbic acid during the fetal development is discussed. The results are compared with those at human, pig and calf fetuses. In analyzing the ascorbic concentration in fetal body fluids of ungulates the high concentration of fructose as an influence-factor in the usual applied methods has to be considered.

Allantois↗

PubMed1991

[Recent knowledge of the function of glucose transport molecules in cell membranes, of the regulation of their composition and of modification of their activity and changes in concentration in diseases (diabetes mellitus, Tumors)].

In the outer membrane of animal cells there exist different isoforms of glucose-transporters (GluT), that contain pores for the facilitative intake of glucose. The content of the various forms of GluT in the different cells is influenced by the stage of development and by the plasma-concentration of glucose. In the regulation of the glucose-concentration in the plasma the content of the skeletal musculature and of the adipose tissue in GluT type 4 plays an important role: It is insulin-dependent. In diabetes mellitus the content of the outer membranes of the cells of the mentioned tissues in GluT 4 is - in dependence of the degree of the disturbance - more or less reduced. The binding of insulin to the receptor in the musculature and in adipose tissue stimulates the transport of GluT 4 from the interior of the cells to the outer membrane. Fasting causes an increase in the content of GluT 4 in the musculature and a decrease in the adipose tissue. Tumor-cells have an increased uptake of glucose with the help of GluT.

Adipose Tissue↗

PubMed1990

[Current findings in the regulation of formation of corticoliberin, pro-opiomelanocortin and ACTH as well as the efficacy of these compounds].

A survey is given on the regulation of the formation of corticoliberin and of pro-opiomelanocortin and of ACTH, respectively, and on the significance of these compounds. The formation of pro-opiomelanocortin is furthered by corticoliberin, vasopressin, oxytocin and angiotensin II. Receptors for the binding of corticoliberin appear in numerous parts of the central nervous system. In various diseases the content of corticoliberin in the plasma and in certain tissues is changed. The inhibition of the ACTH secretion by glucocorticosteroids takes place via a decrease of the formation of corticoliberin and by a reduction of the equipment of the corticotrophic cells with receptors for its binding. The secretion of corticoliberin and of ACTH, respectively, is increased by loads, by hypoglycaemia, by blood losses, by hypoxia and by infections. In the glucocorticosteroid receptors there are 2 types with different affinity to cortisol and corticosterone.

Adrenocorticotropic Hormone↗

PubMed1990

[Various recent findings concerning the formation, mechanism of action and significance of atrial natriuretic peptides (atriopeptins)].

The proatriopeptins consisting of 126 amino acids is formed and stored by the myocytes of the atria. In its disintegration among others develops the alpha-atriopeptins consisting of 28 amino acids, which in normal blood pressure and blood volume, respectively, is secreted only in small quantities. The content of alpha-atriopeptins in the plasma varies approximately between 4 and 12 pmol/l in the course of 24 hours, the half-life period amounts to 1 to 2 min. In an increase of the blood pressure in the atria and in tachycardia the output of alpha-atriopeptins increases. It is bound to receptors of the cells of the glomerular zone, the vessels, the hypothalamus and the kidneys and activates a guanylate cyclase. The main effects of the alpha-atriopeptins are an inhibition of the secretion of aldosterone, vasopressin and renin, a dilation of the arteries, an increase of the glomerular filtration as well as an increase of the sodium and water excretion. In certain diseases of the kidneys and the heart the content of alpha-atriopeptins in the plasma increases.

Aldosterone↗

PubMed1990

[Some recent discoveries of metabolism and function of ascorbic acid].

Some newer knowledge concerning the metabolism of the ascorbic acid as well as its importance for the pituitary gland, the adrenal glands, the immune system and the bone formation are described. A large enrichment of the ascorbic acid is present in the pituitary gland and in the adrenal glands. In the pituitary gland the compound is constituent of the Cu-containing peptidyl-glycine-alpha-amidizating-monooxygenase which among others is necessary for the formation of alpha-MSH a lack of ascorbic acid diminishes the formation of alpha-MSH at stress the increased binding of ACTH to the cells of the middle and inner layer of the adrenal cortex leads to the fact that about 40 to 60% of the quantity of ascorbic acid are delivered. This evokes an increase of the activity of the adenylate cyclase as well as of the C21-hydroxylase: The synthesis and secretion of glucocorticosteroids increases. When there is a deficiency of ascorbic acid the content of cortisol in the plasma increases. The ascorbic acid is a constituent of the dopamine-beta-hydroxylase.

Adrenal Glands↗

PubMed1990

[The content of fresh material, DNA and RNA in different tissues of turkeys during growth. 1. Analysis of the M. pectoralis superficialis, the M. quadriceps femoris, the cerebrum and cerebellum and the spinal cord].

First Communication: Analyses of M. pectoralis superficialis, M. quadriceps femoris, Cerebrum, Cerebellum, and Spinal Cord. The fresh matter level in the M. pectoralis superficialis of turkey was found to increase by a factor of 915, between the first and 224th days from hatching. DNA went up by a factor of 169. The protein: DNA quotient was increased 8.5 times. RNA concentrations in the same muscle went up from 2.65 +/- 0.06 to 6.02 +/- 0.30 mg/g of fresh matter, within the first and seventh days from hatching, and then dropped to 3.61 +/- 0.21 mg/g of fresh matter up to the 14th day, to 2.98 +/- 0.11 mg/g by the 28th day, and to 1.16 +/- 0.05 mg/g by the 224th day. The M. quadriceps femoris exhibited a 111-fold fresh matter increase, from the first through 224th days, while DNA went up by a factor of 44. The cerebrum exhibited a 3.9-fold increase of fresh matter and a 5.2-fold increase of DNA, between the first and 224th day. The cerebellum rises were 6.4-fold or 3.2-fold. Spinal cord values for the same period of time were 27.8-fold for fresh matter and 13.2-fold for DNA.

Animals↗