Microsoft word - physiologie etc. diss. 1995-2004 eng.doc
Bäcker, Natalie (2003): Effect of an oral supplementation with L-argininehydrochloride on bone metabolism of healthy postmenopausal women. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 113 pages. Introduction: Recent experimental studies indicate that nitric oxide (NO) is an important regulator of bone turnover by exerting an anabolic effect on bone cell activity. The NO-level of the human body can be elevated through application of pharmacological NO-donors. The first human trials conducted showed a positive effect of an NO-donor application on the metabolism of human bones. On the other hand L-arginine, the natural precursor of NO- synthesis, is also able to enhance NO-production and, in contrast to NO-donors, seems -in amounts to 30 g- to be free of undesirable effects. Furthermore, an oral L-arginine supplementation causes a significant increase in IGF 1 release, which also has a positive effect on bone metabolism. The purpose of this study was to examine the effect of a six- month daily oral supplementation with 18 g L-argininehydrochloride on the bone metabolism of healthy postmenopausal women. Method: Thirty healthy postmenopausal women, divided into two groups, took part in this study. One group (54.5 ± 4.1 years, 66.3 ± 10.5 kg) received a six-month daily oral supplementation with 18 g L-argininehydrochloride (i.e. 14.8 g free L-arginine). The other fifteen volunteers (55.3 ± 4.4 years, 64.2 ± 9.1 kg) obtained 18 g dextrose as placebo. To eleminate exogen influencing factors the volunteers were asked not to change their activity or eating behavior during the study. For checking purposes nutritional intake and physical activity were documented in protocols during the study. 24-hour urinary excretion of nitrogen, as an indicator for compliance, was analysed for two days at baseline and after two, four and six months. For the analysis of IGF 1, bone formation markers PICP, bAP, osteocalcin, the bone resorption marker CTX as well as for parathyroid hormone and serum-calcium blood was drawn at baseline and after two, four and six months of supplementation. pQCT measurements were performed at trabecular and cortical sites of radius and tibia at baseline, after six months and after one year. Results: Volunteers did not change their eating behavior or physical activity during the six months of intervention. As expected, nitrogen excretion rose in the group with L-argininhydrochloride supplementation and remained constant in the placebo group. Biomarkers of bone metabolism did not change following the L-argininehydrochloride supplementation. The results from the pQCT-measurement showed a change at cortical bone site of the radius in the L-arginine group, but no significant changes were observed at any other site. A change in IGF 1 concentration due to the L-argininhydrochloride supplementation was also not evident. Conclusion: The results show that a supplementation with L-argininehydrochloride is not as effective as an application of NO-donors to influence bone metabolism of postmenopausal women. Alone the cortical thickness of the radius showed a significant increase due to the supplementation. Furthermore in view of the fact that no change in IGF 1 concentration was observed, it was evident that there could be no IGF 1 dependent influence on bone metabolism. Therefore potential factors, which led to the reduced effect, should be checked in following studies, to intensify the impact of the amino acid L-arginine on bone metabolism.
Berns, Georg (1996): Integration of check-lists and mobile lab into a consulting system to extend preventive herd health- and quality programmes in pig production. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 198 pages. The objective of the work at hand is to organize a consulting system oriented towards information and method needs of the pig production farm and, for this purpose, to integrate the use of a mobile lab. In the work presented here, at first the recorded data like biological performance, feeding, slaughtering and economic data are categorized. At second, the new data catagories "environment data" and "health data" are added. For systematically recording environmental data three types of check-lists for piglet-production, piglet breeding and pig-fattening farms are used. The use of the check-lists was tested in empirical tests. The characteristic farm numbers and parts of characteristic farm numbers found were compared with biological performance data and slaughter data for correlation in order to find the probability that disturbances can be correctly evaluated through the evaluation system. The validation revealed significant coefficients of correlation of r = 0,49 to r = 0,80 between characteristic farm numbers and reference data. The results show that the inspection and measuring parameters in check-lists and the calculated partial characteristic farm numbers are appropriate to find the disturbed processes and critical points in production. The calculated farm and partial characteristic numbers lead to a ranking of the farms and farm parts. With the mobile lab and the measured values and calculated characteristic numbers it is possible to carry out process control and determine alarm and limit values. When these values are reached, measures have to be taken. Following the test use of the mobile lab within existing consulting organisations and quality management systems that encompass the production chain, intervention in the following areas can be suggested in order to extend health control during production: Critical point analysis within extended traditional production consulting externally organized intermediate control in the sense of quality management systems on the farm's or chain's leve. Support in the choice of suppliers and their regular assessments within chain-encompassing quality management systems. Finkler - Schade, Christa (1997): Field study during the grazing season on the nutrition of lactating mares and suckling foals as well as on the growth of the foals. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 253 pages. The purpose of this field study was to estimate the provision with energy and nutrients of 149
lactating mares and their suckling foals during the grazing season. From April to October 1993, the feeding in 40 Westphalian breeding farms was recorded and samples of pasture grass, forages and oats were taken. They were analysed for nutrients including macro- (Ca, P, Mg, Na, K) and microelements (Fe, Cu, Zn, Mn) and the values were used for ration cal- culations. The results of the ration calculations were then compared with the recommendations for the provision with energy and nutrients (GFE, 1994). They were expressed as deviation from the recommendations in per cent. A total of 630 rations for the lactating mares and 346 rations for the foals was calculated. The results were divided into horses with pasturing and supplementary feeding and horses only with pasturing without supplementary feeding. The results of the ration calculations show some enormous deviations from the recommendations for the mares as well as for the foals. For the lactating mares of both feeding groups the excess of digestible protein and potassium stands out, that applies also to the zinc deficiencies of the rations without supplementary feeding. The deficiencies in the supply of the foals, independent from the feeding management, with the minerals calcium, phosphorus, magnesium, copper and zinc also stand out. Additionally, the growth of the 149 foals during the first 6 months of life was registered every five weeks. The following body measurements were taken: height at withers, tape-measure, length of cannon bone, circumference of cannon bone and fetlock joint, length of body and girth. The growth rates show intensive growth in the first months and reduce continuously with advancing age. Around the 5th month of life a distinct growth spurt can be observed for all body measurements. The multiple linear regression analysis about the influence of age and nutrition of the foals on growth results in a high R square of about 0.42 for the height at withers. In the regression model the calcium shows a positive influence on growth rate, on the other hand age and the elements sodium, potassium and manganese show a negative influence. The foals were also judged for limb deviations which occur particularly from the 5th month on. The connection between the observed growth spurt around the 5th month of life and the documented nutritional deficiencies of the foals is assumed as the cause. Gothe, Christiane (1999): Haptoglobin as an inflammation marker in the health control of thoroughbreds. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 94 pages. Haptoglobin (hp) belongs to the group of acute-phase-proteins, that rapidly increase their concentration in the blood during inflammation and tissue damage. This study was carried out to explore if hp is a suitable marker in order to establish the health status of thoroughbred race horses. Hp was investigated with the nephelometer-analyzer BN 100 (Behring Diagnostics, Germany) using humanspecific antiserum. Blood samples were obtained from 61 thoroughbreds of one racing stable every four weeks for a period of 12 month (september 1995 - august 1996). In these samples the concentration of hp and additionally the content or activity of enzymes, metabolits and minerals which are usually determined by the „Bonner Informations- und Präventivsystem“ for horses, were examined. For evaluation 375 samples could be used. According to inflammatory reactions measured by the nephelometer-system, values below
55 mg/dl hp were considered as physiological. Hp-concentration did not depend on time of day or sex. Mean hp-values decreased with increasing age. During the year they followed a typical curve with higher values in autumn. Significant changes could be observed in cases of acute inflammation and severe tissue damage (respiratory diseases, open wounds). Hp-mirrows decreased in correspondence to antibiotical treatment. Horses suffering from inflammations of joints or tendons showed slight enhancement of hp- concentration. Vaccination against viral respiratory diseases or rabies clearly caused increase of hp-content in the blood. Correlation coefficients between hp and the other blood parameters were low, although higher hp-values could be recognized in samples with higher concentrations of AST, CK or LDH. It was shown that the determination of haptoglobin in the blood using the nephelometer- system is a valuable instrument for the diagnosis of inflammatory diseases and therefore a support in the routine health control of horses. Gymnich, Stefanie (2001): Haptoglobin as a screeningparameter in health management systems in the piglet rearing. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 128 pages. The aim of the present work was to examine to what extent and at which point in time the parameter haptoglobin could be integrated into a chain oriented health management system. Furthermore it was aimed at assessing the influence of different rearing systems regarding to the practicability of including the parameter haptoglobin into the receiving inspection. Five variants of the customer-supplier-contacts were tested including seven piglet breeding farms, 15 piglet rearing farms and two fattener farms. The results of the preliminary study showed that stress determined by a three hour transport caused no significant changes of haptoglobin concentration in blood of pigs in comparison to the control group. This meant, for the main study, that transport or change of housing as possible reasons for the increase of haptoglobin concentration in pigs' blood could be excluded. In the main study 1559 data from 43 test groups were available. It was found out that piglets from one pedigree had significant lower haptoglobin concentrations at the moment of coming into the rearing than animals coming from different pedigrees. A close connection between the hygienic status of the rearing farm in the in-process inspection and the final inspection, the daily weight gain of the later rearing as well as higher costs of medical treatment and the haptoglobin serum concentration could be underlined. The suggested test strategy combines the measurement of the acute-phase-protein haptoglobin, check lists and a ranking system in the preventive health control. Favourable points in time for the receiving inspection are three days before moving the animals to the breeder or directly at the receiving time, for the in-process inspection three weeks after receipt and for the final inspection three days before moving to the fattener.
Hackländer, Rainer (1997): Investigations to feeding and growth of weanling warm-blooded foals during the stable period. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 112 pages. The aim of this investigation was to analyze the nutrition of weaned warm-blooded foals in Westphalia during their first stable period and to compare these results with the recommendations given by the Society for Nutrition-Physiology (1994). Kind and quantity of feed fed to the foals were recorded on 35 farms on 5 times in intervalls of 5 - 6 weeks. Samples of feedstuffs were analysed for nutrient content including Ca, P, Mg, Na, K, Fe, Cu, Zn, Mn and rations for the foals were calculated. Furthermore several defined growth parameters and the development of the limbs were recorded. Finally it was examined, wether there was a relation-ship between growth, development and provision with energy and nutrients. Nutrition: The analysis of the ration calculations revealed great differences in the provision with energy and nutrients of the weaned foals on the farms. An enormous excess was found in the provision with energy, calcium, phosphorus, magnesium, potassium, iron and manganese. Deficiencies were especially found in the provision with protein, sodium, copper and zinc. Growth: Between the months 5 and 17 the growth rates decreased strongly. The highest growth rates were found up to the age of 10 months. The growth gains of the trunk lasted on until the 2nd year of life. Growth periods characterized by increased gains were found for all parameters in the months 5 to 7, for height at withers also between month 10 and 11. Development of the limbs: Orthopedic developmental bone diseases were especially found in form of enlargements of the fetlock joints, deviations of the limb formation and uncorrect angles of fetlock joints and hoofs. These abnormalities were diagnosed for the most part between the 5th and 10th month of life. Relationship of nutrition, growth and development: A significant influence of different levels of nutrition was prooved for the growth parameters body length and growth of knee to pastern, as well as for the enlargements of the fetlock joints and for steep hoofs. The results underline the importance of ration calculations, which are based on nutrient analysis of the forage used in the farms. This is the basis to choose an adequate supplement. It is advised to match the provision with energy and nutrients of the weanlings with their different periods of growth in order to achieve a constant growth and to avoid orthopedic developmental diseases. Hartmann, Harriet (1999): The importance of the dressage horses’ anatomy on its performance in theory and practice. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University
of Bonn, 101 pages. Aim of the study was to determine which anatomical aspects successful competition-riders and authors of respected literature consider important for prospective dressage horses. An attempt was made to quantify the level of knowledge among successful competition-riders concerning the anatomy and biomechanical aspects of the horse. Riders competing at Grand-Prix level or novice to advanced level were interviewed per questionnaire. After evaluation a comparison between current knowledge and respected equine literature was performed. We found that when evaluating a horses’ aptitude for dressage, shape and positioning of the neck is of eminent importance. An insufficient angulation of the horses’ hind limb is considered negative on the animals dressage performance. Furthermore dressage lessons take considerably longer to learn if the horse has short forelimbs and is narrow in the chest. We could show that a horses’ aptitude for dressage is frequently judged by the quality of its paces and not by its anatomical flawlessness. Often the one is not prerequisite for the other. The interaction between anatomical characteristics and a horses’ movements are very frequently not understood even among riders competing at an international level. Obviously there is no direct correlation between the degree of theoretical knowledge and the riders’ level of competing. The lack of theoretical knowledge is probably due to a practically oriented education among young riders. Added to this, excellent horses resulting from stringent breeding criteria nowadays make the necessity to cope with serious anatomical problems the exception and not the rule. An affluent society prepared to pay considerable amounts for success also plays a significant role. Although German dressage stands in high regard world wide, due to continuous excellent performance, care has to be taken not to neglect theoretical education. The interaction between the horses anatomy and gait should, so as to uphold the high standard, be appreciated by riders of all classes. Heintges, Ute (2003): Investigations on the role of leptin in ruminants. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 150 pages. The aim of the present study was to develop a valid method for the quantification of circulating leptin concentrations in ruminants and to characterise the physiological relevance of this hormone for those species. Using the double antibody technique, a competitive enzyme immuno assay was developed and thoroughly validated. Based on this method and on glucose infusion experiments (hyperglycaemic and euglycaemic/hyperinsulinaemic clamps) in goats, the effects of both, active immunisation against leptin and treatment with leptin injections on glucose and adipose tissue metabolism were investigated. In addition, physiological changes of serum leptin concentrations during growth, pregnancy and lactation were characterised in goats, sheep and cows. The regulation of leptin secretion was investigated by testing the effects of injections with either prolactin, placental lactogen or somatotropin on leptin serum concentrations in goats and cows, respectively.
Serum leptin concentrations were increased by active immunisation and also by injecting leptin into goats but led to divergent alterations of insulin sensitivity: active immunisation decreased insulin sensitivity, whereas leptin injections increased it in pregnant goats. Insulin sensitivity was decreased in lactating goats when compared to pregnant animals. Leptin injections led to decreased serum concentrations of non-esterified fatty acids (NEFA) in pregnant goats. In contrast, lactating goats had higher basal NEFA concentrations and had smaller fat cells than pregnant animals. Lactating animals did not respond to leptin injections in terms of NEFA concentrations. Alterations of leptin serum concentrations inducible by injections with prolactin or placental lactogen were limited to pregnant goats. Prolactin transiently increased leptin serum concentrations within minutes, whereas placental lactogen led to a decrease within hours after the injection. Application of somatotropin to cows decreased plasma leptin concentrations in pregnant cows, but not in non-pregnant, lactating cows. Serum leptin concentrations showed comparable alterations during growth, pregnancy and lactation as reported for humans and for rodents and therefore similar regulatory principles may work for leptin in ruminants regardless of their metabolic particularities. Hermann, Thomas (1998): In vitro effect of 1α,25-dihydroxycholecalciferol and its analogs EB1089 and CB1093 on human endothelial cells and human breast cancer cells. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 108 pages. 1α,25-dihydroxycholecalciferol (calcitriol) affects the proliferation and differentiation of breast cancer cells and has antiangiogenic activity. Thus, this steroid-like vitamin compound offers a novel approach to the systemic treatment of breast cancer. Up to now the clinical use of calcitriol was hampered by its calcium mobilizing effect. Recently, various vitamin D analogs have been synthesized, which show by far a less mobilizing effect on calcium than calcitriol. This project compared the in vitro antiproliferative and antiangiogenic effects of calcitriol and of the two novel vitamin D analogs, EB1089 and CB1093, on human endothelial and human breast cancer cells. Calcitriol as well as both vitamin D analogs (EB1089, CB1093) inhibited the in vitro growth of the human breast cancer cell lines T-47D and MDA-MB-468 in a time- and dose-dependent manner. This antiproliferative effect was independent of the estrogen receptor-status of the tumor cell lines. The proliferation of VEGF-stimulated human umbilical vein endothelial cells (HUVECs) was also inhibited by calcitriol, EB1089 and CB1093. There were no cytolytic or significant stimulatory effects of the tested compounds, neither with breast cancer nor endothelial cells. In HUVECs, calcitriol also suppressed transiently the expression of the VEGF-receptor KDR, but not of the VEGF-receptor flt-1. After a 5-day incubation of T-47D- cells and MDA-MB-468-cells in a media containing 1 µM calcitriol, EB1089 or CB1093, the concentration of VEGF in the cell-free media fell significantly. In contrast, the tested compounds did not modulate VEGF gene expression. Since the relative concentration of VEGF - in relation to a standardized number of 106 cells - showed no significant difference to the control, it seems tenable to attribute the decrease of the concentration of VEGF primarily
to the antiproliferative effect of the tested compounds. From these experiments’ data we can conclude that, due to their reduced calcium mobilizing activity in vivo and their antiproliferative effect on estrogen-dependent and estrogen- independent human breast cancer cell lines as well as on non-malignant human endothelial cells, the vitamin D analogs EB1089 and CB1093 may provide a novel therapeutic tool for the treatment of human breast cancer. Kellersmann, Julia (2003): The influence of O-GlcNAc on APP processing and Cdk5 activity. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 134 pages. N-acetylglucosamine linked O-glycosidically (O-GlcNAc) to serin and threonine residues of proteins is a poststranslational modification of proteins of the cytosol, the nucleus and of the cytosolic domains of transmembrane proteins. It was shown, that the O-GlcNAc-modification of proteins responds reciprocally to phosphorylation and therefore might have a similar regulatory function as the phosphorylation itself. Extending these earlier studies, we were able to show, that PMA treatment (activates PKC) and PUGNAc treatment (inhibits OGH) of N2a- and HEK293-cells, which were transfected with wildtype APP695 (APPwt) or the Swedish mutation of APP695 (APPsw), lead to altered APP processing. PMA treatment of N2a-cells increased APPs-secretion in APPwt-transfected cells, while a decrease of Abeta was observed in both transfectants and in APPwt-transfected HEK293-cells. PUGNAc-treatment increased the Abeta-secretion in APPsw-transfected N2a-cells without changing APPs-secretion. The increase in Abeta-secretion was also shown for APPwt- transfected HEK293-cells. The modification of proteins with O-GlcNAc leads therefore to an increased synthesis of amyloidogenic fragments. We were also able to show, what Cdk5 is O-GlcNAc-modified. Because of the fact, that phosphorylation of Ser 159 negatively regulates Cdk5, the O-GlcNAc-modification might also have a regulatory function. Treatment of N2a-cells with PUGNAc and with the PKA-activator dbcAMP paradoxically lead to an increase in the O-GlcNAc-level of several proteins which was higher than in the presence of PUGNAc alone. The O-GlcNAc-modification might lead to a dysfunction of Cdk5, which then results in increased O-GlcNAc-levels. These observations provide evidence, that the O-GlcNAc-modification modulates APP processing as well as the regulation of Cdk5. Kissenbeck, Silke (1999): Effects of conditioning on glycogen content and glycogen utilization in the gluteus medius muscle of horses. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 111 pages. Introduction. Muscle glycogen is an important substrate for energy production during
exercise. In humans it has been demonstrated that athletes with higher muscle glycogen concentration are those with better endurance (BERGSTRÖM et al., 1976). Therefore an increase of the glycogen concentration through conditioning may be interpreted as beneficial for the endurance of an individual. The aim of the present study was to examine the effects of conditioning horses according to their individual state of performance and to measure the effects on glycogen content and utilization in the gluteus medius muscle. Materials and Methods. The effects of 3 different conditioning programmes on muscle glycogen concentration and utilization in horses were examined. Speed of exercise was selected according to the blood lactate values for each horse derived from a standardized exercise test (SET) before beginning a conditioning programme. Six 2-year-old Haflinger stallions were randomly assigned to 1 of 3 conditioning programmes according to a 6x3 latin square design: 45 min at their individual v1.5 or v2.5 and 25 min at v4. Each conditioning programme lasted 6 weeks (21 exercise sessions), followed by 5 weeks without conditioning (resting period). All exercise was carried out on a treadmill inclined at 17 %. Muscle biopsies were taken 5 times from the gluteus medius muscle at 2 cm and 6 cm depth: before the start and in the middle of the conditioning period, at days 2, 9 and 35 after the last exercise session. Results. Glycogen concentration was not affected by conditioning until 9 days after finishing conditioning at v1.5 and v2.5 for 45 min (p<0.05). By this time glycogen concentration in the muscle samples taken at 6 cm depth increased by 47 % and 48 % respectively and remained elevated until the end of the resting period. The amount of glycogen utilized per minute during the SET was not influenced by conditioning or resting. Conclusions. It was concluded that conditioning at lower intensity and for longer duration seemed to increase glycogen stores in the muscle while faster intensity but shorter duration exercise did not. To increase the likelihood of measuring effects of conditioning programmes on muscle variables sampling should be done at different depths of a muscle and at several days after finishing a conditioning programme. Kosiedowski, Petra (2000): Studies in alterations of faeces consistency in suckling foals during the foal-heat of their mothers and after application of two homoeopathic drugs. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 104 pages. Nearly all suckling foals suffer during the so-called foal-heat (that means the first heat post partum) of the mares under a usually temporary diarrhoea. Aim of this study was to register the continuous alteration of faeces during this period on the basis of defined parameters and to judge precisely the effect of a preventive application of the homoeopathic combinations Nux vomica-Homaccord and Veratrum-Homaccord under standardised conditions. 59 suckling foals from different breeds (Thoroughbred, Trotter, Warmblood) were split up into two groups by random selection. The above mentioned preparations were applied orally with blinding in combined form (5 ml of each) on the 8th, 9th, 10th and 11th day post partum, respectively a Placebo was given. To investigate the alterations of faeces and the effect of the preparations, faecal samples were collected from the rectum on the 7th, 9th, 10th and 12th
day post partum. The examination of faeces consisted of pH, water content, total aerobic and coliform counts. During the research period following results could be obtained: The faecal pH increased from 7.3 to 8.0. There was no statistically significant influence of the drugs on faecal pH. The mean water content increased between the 7th and 12th day post partum from 69% to 82% in the placebo-group and to 74% in the experimental group. A positive influence of the two homoeopathic combination drugs on the water content could be statistically assured already from the day after the first application of the homoeopathic combination drugs. This influence increased with continued application. The total aerobic count increased from 8.8x1012 to 2.6x1013/g faeces in the placebo-group. In the homoeopathic treated group the total aerobic count decreased in general. This positive different development could be statistically assured. In the placebo-group the mean coliform count increased from 5.9x107 to 1.3x108/g faeces. In the experimental group only minor changes in coliform counts could be observed compared with the starting level. The different course of coliform counts development between both groups could be statistically assured already on the first day after treatment. Therefore in respect to the main criteria of the diarrhoea as water content, total aerobic count and coliform count a positive effect of the preventive application of the homeopathic preparation Nux vomica-Homaccord and Veratrum-Homaccord on the"foal-heat- diarrhoea" was statistically assured. Kosswig, Ninetta (2003): Dissecting Class A Scavenger Receptor Mediated Cell Adhesion and Lipoprotein Internalization. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 110 pages. Macrophage class A scavenger receptors (SR-A) are trimeric transmembrane glycoproteins that can bind a variety of ligands including modified lipoproteins and bacterial products. Through its ability to internalize these ligands, SR-A is thought to be involved in many physiological and pathophysiological processes such as host defense and atherosclerosis. In vitro, SR-A also mediates cell adhesion to modified extracellular matrix proteins. However, the physiological role of SR-A mediated cell adhesion is unknown. The goal of this project was to dissect SR-A mediated cell adhesion and ligand internalization through structure- function studies and to develop a mutant of SR-A that specifically lacks the adhesive properties. It appeared that SR-A mediated adhesion and ligand internalization depend on the same extracellular domain. Therefore, I investigated the role of cytoplasmic domains for SR-A mediated adhesion. Different cytoplasmic mutated SR-A constructs were stably expressed in human embryonic kidney (HEK-293) cells. I found that a mutated SR-A deficient in all but the six amino acids proximal to the membrane of the cytoplasmic tail (SR- A∆1-49) was able to mediate cell adhesion, but not receptor internalization. Substitution of the SR-A cytoplasmic tail with that of the transferrin receptor resulted in retention of this chimeric receptor in the endoplasmic reticulum demonstrating that the SR-A membrane proximal
amino acids are also critical for transport of the receptor from the endoplasmic reticulum to the Golgi apparatus. In summary, my results demonstrate that SR-A-mediated adhesion and internalization require distinct cytoplasmic domains and I developed a mutant SR-A (SR-A∆1-
49) that specifically meditates cell adhesion. This mutant will make it possible to specifically address the physiological role of SR-A mediated adhesion. Kreft, Dagmar (1997): Development of an in vitro-model for studying the influence of gliadin on the hydrolases of the duodenal brush border membrane in coeliac disease in remission. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 103 pages. Background: Coeliac disease is characterized by a permanent intestinal intolerance to dietary wheat gliadin and related proteins. Gliadin causes intestinal villus atrophy in afflicted subjects and patients on a gluten free diet recover completely. The molecular mechanism inducing the mucosal damage in coeliac disease is still unknown. The purpose of this study was to evaluate a possible correlation between the mucosal damage caused by gliadin and the biosynthesis of the intestinal hydrolases. Using the organ culture of intestinal biopsies, an in vitro-system for coeliac disease in remission was developed to verify the hypothesis of an impaired biosynthesis. Besides the enzyme activity of intestinal disaccharidases was measured to prove whether this level is also influenced. Patients, Material, Methods: Peroral biopsies taken by suction biopsy capsule or endoscopy of the duodenum from 14 coeliac patients in remission (following a gluten free diet for at least 2 years) and 29 healthy children were organ cultured for 24 hours in presence or absence of gliadin peptides. A peptic-tryptic digest of maize prolamine served as the non-toxic control. The effect of the additives on the biosynthesis of several hydrolases (Lactase-Phlorizin- Hydrolase, Sucrase-Isomaltase, Maltase-Glucoamylase, Aminopeptidase N, Dipeptidyl- peptidase IV, Angiotensin I-converting enzyme) was studied by metabolic labelling of the protein biosynthesis (using [35S]-methionine), followed by immunoprecipitation and SDS- PAGE. Finally the effects were visualized by autoradiography and quantified by densitometric scanning. The influence on the enzyme activity of the disaccharidases lactase, sucrase, isomaltase and maltase was determined by a modificated method of Dahlqvist. Results: A rapid and specific gliadin-induced reduction of the biosynthesis of intestinal hydrolases was demonstrated in biopsies from coeliac patients on a gluten free diet. This phenomenon was statistically significant for all studied disaccharidases and peptidases ( ###>0.01), whereas it was neither seen after incubation with maize prolamine nor in healthy children. On enzyme activity level no effect of gliadin after 24 hours of incubation could be shown. Because of beginning necrosis in the biopsies a longer incubation was not possible, so potential later effects could not be examined. Conclusions: The established model is suitable for studying the in vitro-situation of coeliac disease in remission. Moreover, the results indicate a fast effect of gliadin peptides on inhibiting the biosynthesis of hydrolases of duodenal brush border membranes. However, Gliadin does not seem to influence the post-translational processing of the hydrolases, because both the precursor and the mature forms of the proteins are reduced. It remains
unclear whether gliadin primarily influences the protein biosynthesis or whether this is due to a secondary effect of an impaired mRNA synthesis. The early modifications within 24 hours of incubation suggest an immediate effect of gliadin peptides on the enterocytes, possibly via cytokines. Kreyenschmidt, Judith (2003): Modeling of the quality change of fresh meat and color-change of time-temperature- integrators for monitoring food freshness. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 167 pages. The main purpose has been the investigation of two systems of Time-Temperature- Integrators (Prototype Bayreuth/Haifa and M2/M3 of Co. Lifelines) to control the quality of fresh poultry and pork during the chill chain. Another goal has been the verification of two different models describing the kinetics of spoilage and the kinetics of color-change. One model bases on the scientific Arrhenius-Model and the other model takes advantage of sophisticated mathematical descriptions of the data to create temperature-time-functions. While the food and the TTIs (Time-Temperature-Integrator) have been exposed to different temperatures, its dependency of time and temperature has been investigated with the use of extensive experimental setups: 137 time-runs of spoilage-measurements have been taken and about 300 time-runs to measure the color-change of different Integrators. Each run consisted out of approx. 10 single measurements, so that more than 4000 single data got acquired and analyzed. The results showed that sensory numbers and microbiological parameters are useful to describe food spoilage and the color-change of the Time-Temperature-Integrators. Each model is able to characterize the kinetics of spoilage of food and color-change of integrators and they underline the good capability of the TTI Bayreuth/Haifa to control and check the quality of meat during the chill chain. One major attribute of this Integrator is its adjustability of its behavior in color-change. Therefore the duration of UV-radiation to charge the integrator may be changed or different derivates can be used. Lehnert, Susanne (1998): Implementation of quality management systems in farms exemplary in meat production. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 174 pages. The objective of the work at hand was to exemplarily implement and document quality management systems which are at the first time developed for the structures of german agriculture. The working goups of the pilot project were composed of members of pig fattening farms, production groups of pig fatteners, service organizations and science. An additional task was to prepare some pig fattening farms for the certification according to the
DIN EN ISO 9000ff. standards. The analysis of existing literature shows that animal keeping farms were more and more forced to structure and expose their measures of consumer protection and assurance of origin due to legal restrictions and quality management activities of the meat processing branch. Chain-encompassing concepts of quality assurance focussing on process control are at present theoretically planned, but not yet realized in practise. The proposal developed in the pilot project, how to implement and certify standard oriented quality management systems in pig keeping farms, shall contribute to a faciliated interpretation of the standard for pig production and to an enhanced and broadened implementation. The proposal contains six successive steps: Definition of objectives Project planning and preparation Analysis of deficiencies Development and application of action plans Internal auditing External auditing This so called core modell may generally be used, disregarding the initial basis. The modell distinguishes four possible variants of initial basis: single farm, groups of farms, production community in definite structures and production community with quality standards in vertical integration. Depending on the variant, additional elements will be added to the core modell. As a result of the empirical study, the work supplies structure plans and guidelines as well as solution examples which especially refer to health management measures. Lohmöller, Ludger (1997): Studies for the prevention of postpartal cylce- and reproductive disorders in high yielding dairy cattle with the usage of the homeopathic drugs Traumeel, Ovarium compositum and Hormeel, analysed with progesterone profiles. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 97 pages. Introduction: In the present study the postpartal reproductive period of dairy cattle should controlled and it should prooved, if the use of the homeopathic drugs Traumeel, Ovarium compositum and Hormeel promote an earlier restart of the cyclic ovarian activity post partum and reduce the disorders of cycle and reproduction. Material and Methods: 127 milk cows with the average of 8.941 kg FCM were devided accidentally into three groups. The first injection given postpartum to group 1 was the drug Traumeel, the two injections thereafter consisted of the drug Ovarium compositum. The group 2 started with Traumeel, too, the following two injections consisted of the drug Hormeel. In the group 3, the control group, the cows were given „water for injections“ as placebo. To provide complete and detailed information about normal cyclicity or disorders in reproduction of the cows, progesterone profiles were worked out individually. Complementary, data of milk yield, insemination and parturition were integrated into the evaluation. Results: Analysis of the milk-progesteron profiles: In the groups treated with homeopathic
drugs the ovarian activity started earlier than in the control group. The differences were not significant. Also no significant differences were found in other criteria of the cycle between the three groups. Analysis of reproductive disorders: This study shows, that the limiting value of 28 days p.p. for a female convalescence, suggested in earlier studies, is not physiolocical. 2/3 of the cows in the control group were still acyclic at this time. 49 days p.p. ca. 20 % of the cows stayed acyclic, which is considered to be an acceptable rate. Therefore, the convalescence period for high yielding dairy cattle should be extended for more than two weeks. In the groups treated with the homeopathic drugs there was considerably more cyclic cows. No significant differences were found among the further reproductive disorders looked at this study. Analysis of the reproductive parameters: In group 1 and 2 the first heat was occurred by the farmer about 10 days earlier than it did in the control group. These difference was not significant. The other reproductive parameters and the rates of loss and the reasons for that show slight advantages in the groups treated with homeopathic drugs, but these differences were not significant. Lüpschen, Christoph (1997): Aussagekraft des Body- Condition- Score Testes im Hinblick auf das Partus- Syndroms. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 85 pages. The present doctoral thesis aimed at finding out whether the Body- Condition- Score test is an appropriate means for the management of health care precautionary measures on a dairy farm. With the aid of the BCS- test the nutritional state of the cows was determined on the basis of visible and palpable findings. This question was to be answered with the help of economic efficiency parameters which were to be determined in a field project. For this purpose the disease dates, productivity dates, fertility dates and leaving dates of 248 cows from the „Bergisches Land“ were registered over a one- year period. On the 280 th. day of their pregnancies the body- conditions of these cows were determined with the help of the Body- Condition- Score test. After the test the cows were subdivided into three different groups. The cows which were „slim“ at the beginning of the test formed group 1 with the indexes of 1.5 and 2. Cows with standard weights formed group 2 ( BCS- indexes of 2.5, 3. and 3.5). The „fat“ cows with indexes of 4, 4.5 and 5 finally formed group 3. Cows from group 3 revealed a higher disease rate, less productivity, a lower fertility rate and a higher leaving rate compared with the other cows. Cows from group 1 achieved less productivity and a higher leaving rate compared with cows from group 2. With regard to economic efficiency cows from group 2 showed significantly better results than cows from groups 1 and 3. Based on results from literature as well as those established in this doctoral thesis the Body- Condition- Score test can be recommended to dairy farmers. This test is an appropriate means to optimalise cow feeding within the management of health care precautionary
measures. Marx, S. (1999): Lactate concentration in blood, saliva and sweat of horses during exercise with special emphasis on the Salivette® as a sample collecting device. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 96 pages. The aimes of the present study were to evaluate the Salivette® as a practical, easy to handle and inexpensive device for the collection of saliva and sweat of horses during exercise and to find out if lactate is present in the saliva and/or sweat of horses.
Materials and Methods. 6 Haflingers and 5 Standardbred trotters were used in this
study. All exercise workouts were done on an low speed treadmill with a 17 % incline. The Haflingers were exercised at three different programmes at a constant speed: „25 min“ (3.8 +/- 0.24 m/s), „45 min slow“ (3.1 +/- 0.24 m/s) and „45 min fast“ (3.5 +/- 0.28 m/s). In addition horses had to perform a standardized exercise tests (SET) consisting of several steps of 5 min duration each with one minute of rest between 2 steps. The Standardbreds performed one exercise of 30 min duration at a constant speed ranging from 3.2 to 4.0 m/s. Sweat was collected from the pectoral skin, saliva at the height of the 3rd premolar and under the tongue. The sampling time was always 30 sec. Each substrate was taken during the breaks of the SET and immediately after finishing the continuous exercise. In order to compare lactate concentrations saliva and blood or sweat and blood, resp. these samples were taken simultaneously. During SET blood samples were drawn from the jugular vein and after continuous exercise from the pectoral skin via stab incision. Volumes of sweat and saliva were quantified by extracting fluids from vials with a pipette, lactate analysis was performed enzymaticaly.
Results: The sweat and saliva volumes obtained were not affected by the duration of
the SET or the type of exercise programme but were always sufficient for analysis purposes. Sweat and saliva of horses contained lactate. During SET there was a negative correlation between the lactate concentration in blood and sweat, but not between blood and saliva. No correlation was found between lactate concentrations in the substrates at the end of the continuous exercise. With increasing duration of the exercise blood lactate increased in the Standardbreds, while sweat lactate concentration remained constant.
Conclusions. The Salivette® can be regarded as a practical device for collecting
sufficiant amounts of sweat and saliva for the purpose of analyses. It can be also applied during exercise, because its handling is non invasiv, simple and fast. Performance diagnosis using sweat or saliva lactate concentration and a subsequent renunciation of blood sampling is not possible at this time. Mäß, Carmen (2002): Investigations into the role of the O-glycosidically linked N-acetylglucosamine modification of proteins in the processing of the human amyloid precursor protein.
Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 127 pages. The Amyloid precursor protein (APP) plays a central role in the pathogenesis of Alzheimer’s disease (AD). APP is cleaved by so-called α-, β- and γ-secretase leading to the generation of several proteolytic fragments. This processing of APP is regulated by a variety of different signaling pathways. N-acetylglucosamine O-glycosidically linked to serine or threonine residues (O-GlcNAc) is a ubiquitous intracellular carbohydrate modification of proteins. O-GlcNAc may be involved in the multimerization of proteins and may function as an alternative signal transduction pathway to phosphorylation. Based on former investigations demonstrating that (a) APP is O-GlcNAc-modified and (b) in human brain areas of AD patients the O-GlcNAc expression of proteins is significantly upregulated, the aim of the present study was to elucidate the role of the O-GlcNAc modification of proteins for the proteolytic processing of human APP695. Experiments were performed on N2a cells stably transfected with the cDNA of human APP695. Human APP695 expressing N2a cells exhibited longer neurites and an increased cell adhesion compared to non-transfected, parental N2a cells. These observations are in agreement with former investigations on other APP-expressing cell types. It was shown that human APP695 expressed by N2a cells is O-GlcNAc-modified. The immature protein was more heavily O-GlcNAcylated than the mature form. This observation was shown to be true for the wild type as well as the Swedish mutant of human APP695. Increased O-GlcNAc-levels of proteins did not have any significant influence on the secretion of human APPs and APPs respectively. On the contrary, it resulted in a significant reduction of the secreted human A x-40; this, however, needs to be confirmed in additional experiments. This preliminary result may hint at the involvement of O-GlcNAcylation in the regulation of the proteolytic processing of APP. Furthermore, it was shown that the increased O-GlcNAc-levels of proteins lead to an enhanced expression of the human APP695 in neurites. As a result, O-GlcNAcylation of APP itself or of other proteins may play a major role for the axonal transport of APP. Pfuhl, Ralf (2000): Determination of meat ripening processes and meat quality criterions of pig meat by recording the content of free amino acids with High Performance Liquid Chromatography (HPLC). Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 122 pages. The ripening of Meat is a process of high complexicity including the development of taste and structure of the muscle fibres of a slaughtered animal. The development of the meat quality post mortem can be described objectively by the meat quality parameters pH-value, meat colour and the electric conductivity. After the animal is slaughtered, the muscle proteins are modified and degraded by proteolytic processes, which release peptides and free amino acids in the surrounding muscle tissue.
In this Work the development of the content of free amino acids in samples of the musculus longissimus dorsi of ripening pork at 45 minutes, 24, 48 and 72 hours post mortem were investigated to make an objective statement on the post mortem age and the quality status of pork beside the known quality parameters. To achieve this, the free amino acids of the m. longissimus dorsi of 98 crossbred pigs of defined origin were stored at 4oC and analysed at the times mentioned above post mortem. For the analysis of free amino acids, an amino acid analyser, based on the high performance liqid chromatography (HPLC) was used. Contemporary, the meat quality parameters of the meat samples were determined. The analytical system used in this work is suitable to detect free amino acids in ripening pork. 41 substances can be determined in one detection step. Eight of this 41 substances showed a continuous increase in their content during storing the meat samples (threonine, serine, methionine, isoleucine, leucine, tyrosine and phenylalanine). The content of the amino acid taurin decreased continously in the duration of ripening pork. To each of the investigation times post mortem a defined content of the eight substances (threonine, serine, methionine, isoleucine, leucine, tyrosine, phenylalanine, taurine) can be associated. All meat samples, which tended to produce PSE-Pork, showed higher Alanin levels as normal ripened pork. Carnosin as a dipeptide appeared in high amounts to all times and in all samples. It should be worth to have a closer look on Carnosin in the future. No correlations could be found between the the amount of free amino acids and the measured meat quality parameters in the m. longissimus dorsi of the investigated pig meat samples. Despite of the fact, that no correlations between free amino acids and meat ripening parameters could be found, it is possible to describe different meat aging stages in pigs m. longissimus dorsi by their amino acid profile of the eight substances mentioned. Quade, Reinhild (2004): Importance of NCAM-mediated Signaltransduction for Endocytosis and Neurite outgrowth. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 109 pages. The neural cell adhesion molecule NCAM is a membrane-associated glycoprotein expressed on the surface of neural cells. NCAM plays a pivotal role in neuronal development and rege- neration and is involved in synaptic plasticity associated with learning and memory in the adult. NCAM is a member of the immunoglobuline superfamily and exists in three major isoforms. NCAM180 and NCAM140 are transmembrane proteins with cytoplasmic tails of different length, NCAM120 is bound to the plasma membrane via a glycosylphosphatidylinositol an- chor. All three isoforms have an extracellular domain consisting of five Ig-like domains and two fibronectin type-III domains (Cunningham et al., 1987). Since the PEST sequence of aplysia apCAM – a homologue of NCAM – plays a key role in endocytosis of apCAM (Bailey et al., 1997), we investigated whether the PEST sequence of human NCAM140 is also important for its internalization, which may trigger signal transduc- tion mechanisms implicated in neurite outgrowth in a similar way as has been shown for the
neural cell adhesion molecule L1 (Schmid et al., 2000). The presented results indicate an influence of the PEST sequence of human NCAM140 on its internalization and on neurite outgrowth in rat B35 neuroblastoma cells. Riesen, Guido (1999): Relationships between the rennet coagulation properties of milk and selected biochemical parameters. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 136 pages. The coagulation properties of raw milk play an important role within cheese processing. Direct measurement of the renneting properties requires special equipment and time. Target of this study was therefore to evaluate the relationship between the coagulation properties of milk and some biochemical milk parameters which are used within dairy herd programs as screening parameters to control the feeding regime [acetone and milk urea content ], udder health [pH-value, lactate dehydrogenase activity (LDH)] and milk quality [true protein and casein protein content, protein genotype]. 119 dairy cows were investigated on 3 farms in Brandenburg, Germany. Quarter foremilk samples were taken from each udder quarter at 3 times, starting with the first sampling at day 21 post partum and every next 14 days. For final calculation 1335 samples were evaluated. To determine the coagulation properties the viscosity of the collected milk samples was measured. For this purpose an 8 channel computer based prototype (named CLOTTER) was constructed. For the core evaluation the milk samples were divided into 4 quality grades (G1, G2, G3, G4) according to an index based on rennet clotting time (RCT) and curd firmness. Quality grade 1 (G1) represented the best coagulation properties, quality grade 4 (G4) the poorest. The LDH, the pH-value and the casein protein content were significantly declining from G1 to G4. The urea and true protein content were different between G1, G2 and G3 but not between G1 and G4. Highest values for urea and true protein were measured in G1 and G4. The average aceton value in the milk did not differ between the groups. However 4, 9, and 16 % of the samples in G1, G2 and G3 had aceton levels > 100 µmol/l. Within the different combination of ∃-, 6-Casein and ∃- Lactoglobuline genotype the pairs with at least one B allel of the named protein genotype were superior to the others. Especially 6-Casein BB pairs showed excellent renneting properties. Within a discrimination model the prediction of the coagulation properties of a milk sample was possible at 58,5 % if pH-value and true protein content respective 63,8 % if all screening parameters were included into the calculation. However the classification with the evaluated screening parameters was good for the premium and critical grades (G1, G4 > 75 %; G3: 70 %) but less successful for the average(G2: 51 %). It can be concluded that a suitable milk for premium cheese production must fulfil at least following requirements: pH- value < 6,70; true protein content > 3,00 %, casein number > 80 %, LDH < 85 U/l. The “cheese yield performance“ of a herd should be controlled via a monitoring of the milk urea and aceton content in the milk and by knowing the protein genotype character of each cow. Schöneseiffen, Nicole (2000): A study of the losses in training time incurred by riding horses as a result of illness and the evaluation of training stress and training strain in dressage sport horses. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 115 pages. The purpose of the present study was to obtain epidemiological data on diseases in riding horses which have both participated and not participated in competitions, as well as to observe dressage training and evaluate training stress in horses successfully competing in dressage events. The period of observation was from November 1992 to July 1993. 103 horses from five stables were grouped according to their use and the type of observation as follows: 19 successful dressage sport horses which were intensively observed, 27 dressage sport horses which were competing but not intensively observed, 27 dressage horses which were being trained for dressage but not yet competing and 34 riding horses ridden for pleasure. For the description of type, duration and content of daily training exercise 7 successful L- and 10 S-dressage sport horses were selected. Training stress was evaluated using blood lactate concentration and heart rate levels. Data on diseases was collected by questionnaire and supported by information supplied by the veterinarians. 54.3 % of the 103 horses fell ill at least once during the observation period. 109 cases of illness occurred. Disease frequency differed significantly according to the use of the horses. The intensively observed dressage sport horses fell ill more often than the other types of use. In this group there was also a higher incidence of horses falling ill more than once (63 % of the total) whereas the percentages of the other groups falling ill more than once ranged only from 9 to 22 %. The frequency of the types of diseases also differed significantly. Most of the illnesses (57 %) affected the limbs and also caused the longest time out of training with a mean of 24 days (+ 27 days). This category was followed by respiratory diseases (18 %), the group of "other diseases" (18 %), and the gastrointestinal diseases (7 %). Although the intensively observed horses had a higher incidence of damage to the locomotor system (71 %) compared to the other types of use (43 % to 52 %), the rehabilitation period of 15 days was shorter. With a maximum lactate concentration of 2.2 mmol/l after standardised dressage exercises and a maximum heart rate of 133 beats/min the training stress for the intensively observed dressage sport horses was low compared with jumping, cross-country and race horses. There were no differences between the dressage exercises. All data indicated a purely aerobic energy metabolism. In spite of this, the training of the S-horses seemed to be more intensive than that of the L-horses. This is indicated by the incidence of "dressage training with a rider" which, at 62 %, was higher for the S-horses than for the L-horses (44 %), while the L-horses had a higher incidence of "lungeing" and "free movement" without a rider. In addition, the training session for the S-horses contained more dressage exercises per session (= 25.6) than that for the L-horses (= 14.4). The difference was significant. The walk dominated in the training session for the L-horses, taking up almost half of the total time, whereas the training time for the S-horses was shared almost equally between the walk, the trot and the gallop. The mean heart rate of the L-horses at training differed with 99 beats/min (+ 11 beats/min) significant from the S-horses with 109 beats/min (+ 12 beats/min) of the S- horses, although the L-horses were trained for a longer time (around 48 minutes per training session) than the S-horses (40 minutes per training session). In contrast to this, the S-horses
had 7 % more rest days over the research period than the L-horses. An irregular training programme causes health problems, however, as the uneven training stress can lead to premature wear on the tendons, ligaments and joints. Sommersberg, Britta (2000): Interzelluläre Kommunikation im Ovar: Der Einfluß von FSH auf die funktionelle Kopplung durch Gap junctions sowie die Phosphorylierung und Expression von Connexin 43. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 92 pages. In the ovarian follicle, granulosa cel s (GC) are functionally coupled by gap junctions (GJ), which mainly consist of the GJ protein connexin 43 (Cx 43). GJ are intercellular channels, which enable adjacent cells to exchange ions and molecules of a molecular range less than 1,000 Da. While studies in Cx 43 Knock Out (KO) mice indicate the indispensable role of Cx 43 in follicular development, little is known about the regulation of this protein in GC. However, we and others found that Cx 43 protein and mRNA levels are higher in large follicles than in small follicles. Since follicular development is tightly regulated by Follicle Stimulating Hormone (FSH), we hypothesized that FSH could also be involved in the regulation of Cx 43. Because multiple factors present in a follicle do not allow to dissect out the action of FSH we addressed this question by using a rat granulosa cell line (GFSHR-17), which expresses the FSH-receptor and forms GJ. In this cell line, FSH acutely improved functional coupling as observed by a modified single-cell whole-cell patch clamp technique. This increase in GJ communication was associated by a decrease in phosphorylation of Cx 43 observed within 10 minutes after addition of FSH. Furthermore, Cx 43 mRNA levels were elevated 6 - 9 h after addition of FSH to the cells. This increase in Cx 43 mRNA was paralleled by reduced proliferation state and increased steroid synthesis in GFSHR-17. Additionally, Cx 43 protein levels increased 24 h after addition of FSH. In particular, the polyphosphorylated form of Cx 43 increased, whereas the less phosphorylated form decreased. In summary and conclusion, FSH acutely improves GJ communication through existing GJ. This regulation involves dephosphorylation of Cx 43. In long term, FSH increases Cx 43 gene and protein expression. The higher phosphorylation state of Cx 43 observed in this time period may implicate the more stable form of Cx 43. Thus, FSH is a direct regulator of GJ communication and Cx 43 protein phosphorylation as well as Cx 43 gene expression. The observed changes in GFSHR-17 cells indicate that FSH acts to regulate the cell to cell communication via GJ in differentiating follicular GC. Stelz, Hansjochen (1998): Investigations on the aerobic and anaerobic biological fixed film filtration in a marine recirculating aquaculture system. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 133 pages.
The suitability of a closed recirculating aquaculture system using saltwater was investigated. This study focussed on: Acceleration of the start-up period of the biofilter Use of the controlled denitrification Investigation on the biofilter performance and factors influencing the biofiltration. The trials were run in three closed recirculation systems. Saltwater was prepared by adding sea-salt to tap water. Rainbow trout (Oncorhynchus mykiss) served as reference animals in trials where the systems were stocked. Stocking densities ranged from 6.22 to 58.6 kg/m3 rearing unit. Three diets with different crude protein concentrations (44.2; 48.3 and 53.3 % in dry matter) were used. The shortest start-up period (5 days) to adapt biological filtration (nitrification and denitrification) from freshwater to seawater was achieved by increasing the salinity in a single step. NO3-contents and pH-values were stabilized by controlled denitrification. NH4-excretion of fish rose depending on the dietary crude protein concentration and was 35; 39 and 54 g N per kg dry diet. The demand on methanol, which was used as organic carbon source for denitrification, was depending on the oxygen-input into the denitrification-unit and the feed composition. The maximum performance of the denitrification-unit could not be detected. The ammonia removal rate was inhibited by lower pH-values and higher concentrations of suspended solids in the rearing water. The maximum removal rate was 0.20 g N *m-2 *d-1 (water temperature 14.4°C). Strompen, Oliver (2001): Studies related to the endogenous steroid profiles in horse urines using gas chromatography/mass spec-trometry. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 285 pages. Destination: The purpose of the present study was to develop and validate a specific analysis procedure for the determination of qualitative and quantitative endogenous steroid profiles in horse urines using gas chromatography/mass spectrometry (GC/MS). Profiles of steroid hormones (estrogens, androgens, progestagens and corticosteroids), their precursors and their metabolites were monitored. Methods: The pattern of urinary excretion of steroids was determined by gas chromatography/mass spectrometry (GC/MS) in 322 thoroughbred horses (106 colts, 113 mares, 103 geldings). The method included deuterated internal standards, e.g. [2,2,4,4-2H4]- etiocholanolone, solid-phase extraction, derivatisation (trimethylsilylation) and GC/MS. Results: Full-scan screening identified 2 androstenes, 11 androstanes, 3 estratrienes, 3 estranes, 1 estrene, 5 5-pregnenes, 5 4-pregnenes and 10 pregnanes. The analysis procedure was categorized as standard- or reference procedure on the basis of characteristic properties, e.g. detection limits, selectivity and uncertainty. The procedure was validated at three calibration ranges. The selected ion mode was used for quantitation from calibration curves, which exhibited a linear response (r > 0.98). The lower quantification limits
of the steroids ranged between 0.5 and 2 ng/ml (the detection limits about 2-fold lower). The assay recoveries of steroids were reproducibly high. The intra- and inter-assay coefficients of variation were < 10 %. Urinary univariate reference ranges of selected endogenous steroids were measured using samples collected during regular “doping” control. The urinary steroid excretion pattern, measured by GC/MS, is a noninvasive, high specific and nonselective method in the differential diagnosis of abnormal steroid matabolism. Zelczak, Georg (1998): Longchain-polyunsaturated fatty acids in the nutrition of newborns and infants. Institute of Physiology, Biochemistry and Animal Hygiene, Faculty of Agriculture, University of Bonn, 88 pages. Background: Recent clinical studies have shown the importance of dietary long chain poly- unsaturated fatty acid (LC-PUFA) supplementation especially docosahexaenoic acid (DHA) and arachidonic acid (AA) in preterm infants for visual acuity and psychomotor development. It is less clear if term infants would also benefit from LC-PUFA supplementation to infant formula. The aim of the present study was to evaluate, wether LC-PUFA supplementation of infant formula results in a comparable LC-PUFA status of blood and a comparable development of psychomotor and visual functions like breast-fed infants. Patients, Material, Methods: A total of 123 healthy term infants were included in the prospectiv, randomized double-blind-study. They received human milk (HM; n=65) as a control group or were randomized to a conventional formula (FM-; n=25) or LC-PUFA enriched formula (FM+; n=33; docosahexaenoic acid, DHA: 0,54% of total lipids; arachidonic acid, AA: 0,11% of total lipids) for the first 4 months of life. Venous blood was taken at birth from the umbilical cord and at the age of 2, 4 and 12 months. Lipids were extracted from erythrocytes and plasma with chloroform/methanol. Lipidclasses such as phospholipids, triglycerides and sterol esters were seperated by thin-layer chromatography and fatty acid methylesters were analysed by high-resolution capillary gas-liquid chromatography. Psychomotor development, body weight, height, head circumferences and skin fold measurements were evaluated at the age of 2, 4, 9, 12 and 18 months. At 9 months visual acuity was measured by preferential looking procedure. Results: Altogether the fatty acid distribution in the lipidclasses of the study groups reflected the dietary intake of LC-PUFA. Significantly higher amounts of DHA were found in the blood of the infants receiving FM+ in comparison to HM fed infants at the age of 2 and 4 months. In contrast the FM- group showed lower values. Both formula groups had significant lower amounts of AA in the plasma lipidclasses at the age of 2 and 4 months. Remarkably high values of docosatetraenoic acid (DTA) and docosapentaenoic acid (DPA) could be found in the phospholipidclasses of FM- fed infants at the age of 2, 4 and 12 months. Psychomotor development, body weight, height, head circumferences and skin fold measurements were not significantly different among the dietary groups at 2, 4, 9, 12 and 18 months. Just so no differences were found in the visual functions at the age of 9 months. Remarkably there was an accumulation of drop outs because of gastrointestinal symptoms in the FM+ group. Conclusions: LC-PUFA enrichment of formula for term infants effectively enhances
erythrocyte and plasma LC-PUFA amounts. However, a better adaptation of LC-PUFA content of the used formula to the contents of human milk is desirable, since DHA levels were too high and AA levels too low in the FM+ group. Infants feeding with conventional formulas had inadequate LC-PUFA levels. Therefore, a supplementation of infant formula seems to be necessary to reach comparable amounts of LC-PUFA in the blood of term infants. On the other hand, no differences were found in the psychomotor and visual development among the dietary groups. For a better evaluation of the visual and cognitive development long-term follow-ups should be done. Beyond it is necessary to investigate, wether there is a correlation between the occurance of gastrointestinal problems and the supplementation of LC-PUFA.
Virginia Cooperative Extension PUBLICATION 354-312 Three-prong American ginseng plant. Producing and Marketing Wild Simulated Ginseng in Forest and Agroforestry Systems Introduction other hand, wild ginseng sells for over $300 a pound andthe market demand in Asia for wild roots is practicallyAmerican ginseng ( Panax quinquefolium , Araliaceaefamily) is a familiar plant t
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