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Biomedical subjects

K Bickhardt

Publications and source records attributed to K Bickhardt.

At least 37 records · Page 2Linked to original sources
PubMed1994

[The contributions of the hormones insulin, cortisol, somatotropin and total estrogen to the pathogenesis of sheep ketosis].

The concentrations of hormones, metabolites and electrolytes in plasma of 45 ewes have been examined repeatedly during gestation (day 80 to 149) and at the third day of lactation. Healthy single pregnant (n = 8) and twin pregnant ewes (n = 12) have been compared with ewes sick with subclinical (3-hydroxybutyrate > 1,0 mmol/l, n = 6) and clinical (3-hydroxybutyrate > 1,6 mmol/l, n = 19) pregnancy ketosis. The concentration of 3-hydroxybutyrate, glucose, calcium, sodium and growth hormone in the plasma of the healthy animals were higher post partum than ante partum, while the concentrations of inorganic phosphorus, cortisol and total oestrogen were lower post partum than during pregnancy. In the pregnant ewes the concentrations of 3-hydroxybutyrate, bilirubin, total oestrogen and growth hormone in the plasma increased, while the concentration of insulin decreased with raising number of fetuses. In comparison with the healthy twin pregnant ewes the animals with subclinical and clinical pregnancy ketosis showed increased values of bilirubin, glutamate-dehydrogenase, growth hormone, total oestrogen, cortisol and cortisol/insulin ratios as well as decreased values of glucose, insulin and potassium. Individual differences of the animals within their groups were observed for the examined hormones as well as for glucose, calcium, sodium and potassium (analysis of variance). Beside multiple pregnancy low insulin values and high cortisol/insulin ratios, which are obviously due to individual disposition, influence enhanced ketogenesis and disorder of glucostasis.

Animals↗
PubMed1993

[Clinical laboratory diagnosis in swine practice].

Necessity and facilities of clinical laboratory diagnostics in veterinary swine practice are discussed. The selection of suitable tests with regard to diagnostic relevance and reliability is pointed out. Typical test features (sensitivity and specificity) as well as disease dependent parameters (prevalence, positive or negative predictive value) are presented and illustrated by means of urinary tract infections in sows. It is concluded that a specific selection of tests and probands closely related to diagnosis is more successful than the use of unspecific multi-analysing procedures (profile tests).

Animals↗
PubMed1993

[Eperythrozoonosis in sheep].

In 1990/91 eperythrozoonosis in the sheep was seen in our clinic for the first time. In 10 animals out of 4 flocks infection with Eperythrozoon ovis was diagnosed. Most of the animals showed a transient parasitaemia with a temporary anaemia. A chronic high grade parasitaemia and anaemia were produced in one sheep by splenectomy. This animal showed haemoglobinuria following a haemolytic attack. In a lamb a high grade chronic parasitaemia occurred spontaneously. The parasitaemia lasted for over 7 months, and the lamb eventually died.

Anemia↗
PubMed1992

[Use of the Reflotron system for the determination of creatine kinase (CK) in the blood of swine, sheep, cattle, horses and dogs].

The Reflotron-CK test was evaluated with blood samples of healthy and diseased pigs, sheep, cattle, horses and dogs in relation to the standard CK-NAC test (UV-method). The precision within the series on the day of blood sampling was better than VK = 7.5% (coefficient of variation) with both methods. The day to day precision was estimated by using deep frozen plasma and was in the same order of magnitude with the Reflotron-CK and the UV-method (CV less than 10%). While fresh whole blood of sheep, cattle, horses and dogs respectively should be applied directly onto the dry reagent carrier with the Reflotron-pipette (32 microliters), the blood samples of pigs must be diluted (200 microliters 0.9% NaCl-solution and 32 microliters blood, factor 7.25) before determination with Reflotron-CK. In the five species mentioned the correlation between Reflotron-CK and CK values obtained with the standard UV-method was satisfactory (r greater than 0.96). Systemic deviations of the Reflotron-CK values should be corrected by calculation formulae, given in the paper.

Analysis of Variance↗
PubMed1992

[Elimination kinetics of several clinically relevant enzymes in the blood plasma of cattle after intravenous bolus infusion of homologous preparations].

Extracts of homologous organs (liver, muscle) and of colostrum were infused intravenously in cattle of two different age groups: heifers (n = 9, each preparation was infused in 3 animals) and calves (n = 6, preparations from liver and muscle were infused in 3 animals each). Parameters of elimination kinetics were determined for some clinically relevant enzymes. Enzyme elimination was quicker in the younger animals. The volume of enzyme distribution was comparable to plasma volume. Biological half-lives in calves and heifers respectively were: CK from muscle 3.46 +/- 0.65 h and 8.27 +/- 3.27 h, AST from muscle 9.74 +/- 1.38 h and 33.48 +/- 3.74 h, AST from liver 14.99 +/- 0.81 h and 16.71 +/- 0.58 h, GLDH from liver 14.61 +/- 1.88 h and 25.09 +/- 4.13 h, SDH from liver 13.95 +/- 2.25 h and 17.68 +/- 0.81 h, GGT from colostrum 1.69 +/- 0.95 h (only heifers).

Animals↗
PubMed1991

[Creatinine clearance as the foundation for clinical determination of kidney function in swine].

Comparative examinations of renal function using inulin- and endogenous creatinine-clearance tests in 5 pigs showed nearly identical values of glomerular filtration rate (GFR). Based on this relation 79 healthy pigs, weighting 2 kg to 230 kg were investigated using the creatinine-clearance test for determination of normal values of GFR and urine flow rate (Vu) as well as renal excretion (E), renal clearance (Clr) and fractional excretion (FE) of urea, sodium, potassium, calcium, phosphorus, glucose and lactate. The renal excretion of creatinine (E-Creat) was closely correlated with the body weight. Therefore it is possible to use the body weight for estimation of E-Creat and to calculate GFR and Vu using plasma and urine concentrations of creatinine independent of a timed volumetric urine collection. Subsequently E, Clr and FE of electrolytes or other endogenous substances can be evaluated. Finally the practicability of this procedure for detection of disturbed glomerular filtration or tubular reabsorption was demonstrated in piglets suffering from colidiarrhoea and/or transmissible gastroenteritis.

Animals↗
PubMed1991

[The diagnostic significance of different blood parameters and liver biopsy in chronic copper poisoning of sheep].

In a flock of sheep to which food with excess copper (= Cu) had been fed for some months 39 animals died of chronic copper toxicosis. In 5 sheep of this flock the plasma concentrations of the enzymes glutamate dehydrogenase (GLDH), sorbitol dehydrogenase (SDH), aspartate-amino-transferase (ASAT) and copper were measured several times over a period of 100 days. At day 23, 58 and 97 needle biopsies of the liver were taken. The biopsies were used for histological examination and Cu-analysis. After 100 days the sheep were slaughtered and chronic copper poisoning was diagnosed by raised Cu concentration and typical histological alterations in the liver. The activities of GLDH and SDH in the plasma of the 5 sheep were consistently above normal, ASAT activity and the plasma Cu level were raised only occasionally. The results of Cu determination in biopsy samples were of little predictive value compared with post mortem Cu analysis of the liver.

Animals↗
PubMed1990

Pharmacodynamic effects of serotonin (5-HT) receptor ligands in pigs: stimulation of 5-HT2 receptors induces malignant hyperthermia.

In pigs, the serotonin-2 (5-HT2) receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), 0.8 mg/kg, induced "psychotic" behaviour (e.g., grimacing, backward locomotion, blank stare) and a muscular syndrome, which is known as malignant hyperthermia (MH) in pigs and humans. This syndrome is characterized by generalized skeletal muscle rigidity, leading to an increase in body temperature, marked acidosis, hyperkaliaemia, cyanosis and elevation of lactate, carbon dioxide and the muscle enzyme creatine kinase (CK) in plasma. In pigs which were selectively bred for susceptibility to MH induction by known triggering agents, such as halothane, the administration of DOI was fatal in 3 out of 5 animals. In genetically susceptible pigs, MH was also induced by 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), 0.5-1.8 mg/kg, and D-lysergic acid diethylamide (LSD), 60-110 micrograms/kg. Furthermore, 5-MeO-DMT and LSD induced head shakes in the animals, which had not been observed after DOI and could not be blocked by 5-HT2-antagonists, ketanserin (0.5-5 mg/kg) and ritanserin (1-2.5 mg/kg). The psychotomimetic effects of 5-MeO-DMT could be blocked by ketanserin or ritanserin, which, depending on the dose, also reduced or totally prevented the hyperthermia and metabolic changes induced by 5-MeO-DMT in pigs. Administration of 5-MeO-DMT, 1.8 mg/kg, was fatal in 4 of 5 MH-susceptible pigs, whereas pigs injected with this dosage after pretreatment with ketanserin (0.5-5 mg/kg) or ritanserin (1-2.5 mg/kg) did not die. In pigs from MH-resistant littermates, administration of 5-MeO-DMT was not fatal. Comparison of metabolic changes in susceptible and non-susceptible pigs suggested that the marked increase in plasma potassium, which arises principally from damaged muscle cells, is primarily responsible for the fatal effect of DOI and 5-MeO-DMT in genetically susceptible individuals. In MH-susceptible pigs, which were anesthetized, relaxed and artificially ventilated, 5-MeO-DMT did not induce hyperthermia, thus substantiating that the marked hyperthermia observed in conscious pigs was a result of muscle activation and not due to effects on thermoregulation or blood pressure. The results indicate that hallucinogenic drugs with 5-HT2 agonistic effects trigger a life-threatening syndrome, MH, in genetically susceptible pigs. 5-HT2 antagonists, such as ketanserin or ritanserin, are capable of counteracting the fatality of this syndrome.

Amphetamines↗
PubMed1990

[Comparative studies of the clearance of inulin and creatinine in swine].

Endogenous creatinine clearance was determined in 5 healthy female pigs of different body weight simultaneously to the clearance of inulin. The average creatinine clearance (3.74 +/- 0.57 mg/min/kg) has been found to be 7% higher than inulin clearance indicating some tubular secretion of creatinine. However, since this difference was not significant, the endogenous creatinine clearance is a practicable method for the measurement of glomerular filtration rate in swine. Data of creatinine concentration in plasma and of creatinine excretion showed close relationships to the body weight. It is discussed, whether the glomerular filtration rate can be predicted from the creatinine concentration in plasma and creatinine excretion, which might be estimated from the body weight without quantitative urine collection.

Animals↗
PubMed1989

[Various heart arrhythmias in swine (short communication)].

Heart arrhythmias were observed in 7 of 147 pigs suffering from heart and circulatory insufficiencies. Endocarditis valvularis and cardiomypathy were the dominant causes of the arrhythmias. Electrocardiographic abnormalities of the cases are discussed.

Animals↗
PubMed1989

[Glucose metabolism in sheep in different reproductive stages and with ketosis using the intravenous glucose tolerance test (IVGTT)].

Kinetic parameters of glucose metabolism were determined in 17 healthy ewes during different metabolic stages and in 8 spontaneously ketotic sheep by the IVGTT with low doses of glucose (0.8 mmol/kg) as well. The endogenous turnover rate (R) was calculated by using the total clearance (Cl), derived from the IVGTT. The values of R, determined in healthy ewes by this technique are in agreement with values presented in the literature, which were derived from kinetic studies with 3H- or 14C-labeled glucose. There were no differences in the mean values of R and Cl in non-pregnant, highly pregnant and ketotic ewes in our study. The plasma concentration of glucose (C) was significantly correlated with R in highly pregnant healthy and ketotic ewes; there was no such correlation in the group of non-pregnant and early pregnant sheep. In highly pregnant ketotic ewes the mean value of C was lower than in healthy ewes but there was no significant correlation between the plasma concentration of glucose and that of 3-hydroxybutyrate. It is concluded from the study, that the control of glucostasis fails frequently during late pregnancy in ewes and that ketosis of sheep is related closer to the excessive lipid mobilisation than to disturbance of glucostasis.

Acidosis↗
PubMed1988

The effects of Sarcocystis miescheriana infections on blood enzymes and weight gain of stress-sensitive and stress-insensitive pigs.

The effects of mild Sarcocystis miescheriana infection on blood enzymes and body weight were compared in stress-sensitive (halothane positive) and in stress-insensitive (halothane negative) pigs. Ten halothane-positive pigs (Group A) and ten halothane-negative pigs (Group C) with a mean body weight of 36 kg were each inoculated orally with 50,000 sporocysts of S. miescheriana. Twelve halothane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Five days before infection (a.i.) and 58 days post infection (p.i.) all pigs were myostress challenged (creatine kinase test). During the whole period of the experiment (3 weeks a.i. to 13 weeks p.i.) body weights were determined and blood samples taken at weekly intervals. Creatine kinase (CK), aspartate aminotransferase (ASAT) and Sarcocystis antibody titres were determined. The infection induced slightly elevated temperatures (max. 42.8 degrees C) and transient reduced food intake during the 2nd and 3rd week p.i. The CK values of the infected pigs in Groups A and C increased from Day 28 p.i. onwards, and were significantly higher than those of the pigs of the non-infected controls (Days 35-77 p.i.). The ASAT values of the infected groups (A and C) increased from Day 21 p.i. onwards, and were significantly higher than those of the non-infected controls from Days 28-77 p.i. The myostress injection at 5 days a.i. (1st CK test) resulted in significantly higher CK and ASAT values in stress-sensitive pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[Stress reactions in clinically healthy sows at the time of birth and their relationship to the CK test].

Concentrations of the enzymes creatine kinase (CK) and aspartate aminotransferase (ASAT/GOT) were determined in plasma of 100 gilts and 175 sows at the 112. day of pregnancy and one day after parturition. Gilts and sows were divided into a stress resistant (n = 146) and a stress susceptible group (n = 129) following the creatine-kinase-test carried out after the performance test period at a body weight of 90 kg (CK-90). Stress susceptible gilts and sows showed higher CK-values before and especially after parturition than stress resistant ones. Significant correlations were demonstrable between CK-90 and the CK values before and after parturition (r = 0.5). Regarding body temperature, respiration rate and heart frequency as well as the percentage of stillborn piglets, the two groups of sows did not differ from each other. The increase of enzyme activities after parturition was not influenced by prophylactic treatment with prostaglandin-F2-alpha or beta receptor blocking agent. The beta blocking agent Carazolol, however, caused a transient depression of heart rate after parturition.

Adrenergic beta-Antagonists↗
PubMed1988

[Stress reactions in sows during difficult births and after transport].

Reactions during dystocia and after transport were studied in 66 sows (including 47 sows of German Landrace and 11 of German Large White) by examination of clinical parameters and blood constituents. 15 sows (group 1) died within 24 hours after investigation (7 had to be slaughtered before surgery and 8 died afterwards). 51 sows (group 2) survived dystocia or caesarean section respectively. A small chance of survival was correlated with fetal death, insufficiency of the peripheral circulatory system, lactacidaemia and metabolic acidosis, associated with increased respiratory and heart rates, as well as muscle degeneration with elevated plasma levels of creatine kinase (CK). The investigation showed, that reactions to stress of dystocia chiefly depend on individual stress susceptibility, but less on duration of birth, fetal death and toxaemia.

Animals↗
PubMed1987

[Use of the Reflotron system for laboratory diagnosis in swine and sheep].

The "Reflotron" system (Boehringer Mannheim) was compared with standard laboratory methods for determination of blood values, e.g. haemoglobin, glucose, urea, ASAT/GOT and GGT in pigs and sheep. Various different commercial control sera as well as blood and plasma samples from pigs and sheep were used for evaluation of its precision. The day-to-day precision of all parameters was satisfactory. The accuracy of the values was tested in 56(48) blood samples of healthy and sick pigs (sheep) by using standard substances (glucose, urea) and by comparing them with values measured by standard laboratory methods. There were systematic differences between "Reflotron" and other values in the glucose- and enzyme-values, which can be corrected with the help of conversion factors. In pigs, the enzyme GGT can not be determined accurately with the "Reflotron" system.

Animals↗