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Biomedical subjects

M Hegedüs

Publications and source records attributed to M Hegedüs.

At least 19 recordsLinked to original sources
PubMed1996

The role of feed protein quality in reducing environmental pollution by lowering nitrogen excretion. III. Strategies of feeding: a review.

To meet the requirements of pigs a better supply of amino acids can be achieved by using ileal digestibility data of feed ingredients in least-cost feed formulation. Digestibility of amino acids can be improved by addition of multienzyme products, antimicrobial additives and probiotics. Protein accretion may be positively influenced by beta-adrenergic agonists. An adequate ratio of protein to dietary energy is essential to achieve optimal protein utilization. Nitrogen output can be minimized by improving feed efficiency and by eliminating antinutritional substances with adequate processing. The use of the ideal protein concept helps to minimize nitrogen excretion. Management and animal hygiene also have a significant impact on the overall nitrogen balance in animal production.

Adrenergic beta-Agonists↗
PubMed1995

Electrophysiological effects of dridocainide on isolated canine, guinea-pig and human cardiac tissues.

The cellular electrophysiological effects of dridocainide (EGIS-3966), a novel class I antiarrhythmic agent, was studied using conventional microelectrode techniques in canine cardiac Purkinje fibres and papillary muscle preparations obtained from humans and guinea-pigs. In each preparation, dridocainide (0.6-2 mumol/l) decreased the maximum velocity of action potential upstroke (Vmax) in a frequency-dependent manner, although marked differences were observed in its effects in Purkinje fibre and ventricular muscle preparations. In canine Purkinje fibres, action potential duration measured at 50% and 90% of repolarization was decreased, while action potential duration measured at 10% of repolarization was increased by dridocainide. In addition, the plateau of the action potential was depressed by the drug. These changes in action potential configuration were not observed in guinea pig or human papillary muscles. The offset kinetics of the dridocainide-induced Vmax block were different in Purkinje fibres and in ventricular muscle: the slow time constant of recovery of Vmax was estimated to be 2.5 s in dog Purkinje fibre and 5-6 s in human and guinea-pig papillary muscle. In guinea-pig papillary muscle, the rate of onset of the Vmax block was 0.15 and 0.2 per action potential in the presence of 0.6 and 2 mumol/l dridocainide, respectively. Dridocainide also decreased the force of contraction in this preparation. On the basis of the present results, dridocainide appears to possess mixed class I.C and I.A properties, with I.C predominance in human and guinea-pig ventricular muscle. Present results also indicate that results of conventional classification of class I drugs may depend on the parameters chosen, as well as on the preparation selected.

Action Potentials↗
PubMed1995

Effect of methionine and its related compounds on rumen bacterial activity.

The effect of several methionine sources (L-methionine = L-MET; DL-methionine = DL-MET, DL-S-methyl-methionine-sulphonium-chloride = SMM; N-hydroxymethyl-DL-methionine-Ca = NHM; methionine-hydroxy-analog free acid = MHA; methionine-sulphoxide = MSO) on rumen bacterial growth was studied using a new methodical approach which utilises a methionine free assay medium (Bacto Methionine Assay Media, Difco) supplemented by increasing quantities of the methionine sources and inoculated with one drop of diluted rumen bacteria. The optical density was measured after 18 h incubation on 39 degrees C. L- and DL-MET promoted the highest growth response, while SMM and NHM exerted significantly (p < 0.05) lower optical densities. MHA and MSO showed no growth response. The methodical approach and the possible bacterial strains, which might have contributed to the growth response have been discussed.

Animals↗
PubMed1995

Antiarrhythmic activity of oximethers.

More than sixty 2-substituted-cycloalkanone-oxim-/2-hydroxy-3-dialkylamino/- propylethers were investigated on aconitine induced ventricular arrhythmia model in rats. According to the structure-activity relationships cyclohexanes containing diisopropylamine in the basic group were the most effective derivatives. Based on the highest per os activity and lowest toxicity EGIS-3966 (ED50 values 1.21 mg/kg iv. and 27.3 mg/kg per os) was selected for further development.

Aconitine↗
PubMed1993

The role of feed protein quality in reducing environmental pollution by lowering nitrogen excretion. I. Survey of principles in protein evaluation for monogastrics: a review.

Environmental pollution by faecal nitrogen excretion motivates a renewed interest in optimising protein utilization of growing-finishing pigs in intensive pig production areas. The importance of digestibility of proteins, availability of amino acids, and the extent of protein retention is emphasized for reducing nitrogen excretion. The principles of various chemical, microbiological, biochemical and biological methods in feed protein quality evaluation offering a better adjustment of protein supply to the requirements of the animal are surveyed.

Animal Feed↗
PubMed1993

The role of feed protein quality in reducing environmental pollution by lowering nitrogen excretion. II. Choice of an assay for monitoring protein quality and predicting protein utilization.

The optimum protein nutrition of farm animals allowing minimum nitrogen excretion is a compromise between performance (weight gain) and efficiency of protein utilization. The use of highly digestible feed ingredients allowing maximum nitrogen retention requires assay techniques which are suitable for monitoring protein quality of the feed or predicting nitrogen utilization of the animal. The various assay methods reflecting the protein metabolism of the animal may give different information according to the criteria, which they utilize. Therefore, a suitable assay should be selected with care, depending on the question to be answered. The various aspects of selecting assays for monitoring the protein quality of feeds and predicting protein utilization by the animals are discussed.

Animal Feed↗
PubMed1992

[Experience with the Direx Tripter X-1].

In nonselected patients 81.5% stone-free rate could be reached in 3 months. In authors's opinion Direx Tripter X-1 is suitable in the treatment of renal and ureteral calculi. They treated staghorn calculi by ESWL monotherapy with success. The Direx lithotripter was found to be effective and easy to operate; the potential cost reduction is of great significance. The treatment requires general anaesthesia and the equipment causes significant noise. After all, Direx lithotripter is a useful machine in the armamentarium of stone disease treatment.

Adolescent↗
PubMed1992

Experience with the Direx Tripter X-1 shock-wave lithotripter.

The authors give account of the experience they gained with the Direx Tripter X-1 (ESWL) apparatus. In a random material they succeeded to render 81.5% of the patients stone free within three months. They judge the apparatus suitable for in situ treatment of pelvic and ureteric stones and for the monotherapy of staghorn calculi. It is easy to handle, inexpensive to buy and maintain but noisy to operate, moreover the patient has to be anaesthetized. All in all it is highly useful in the treatment of renal lithiasis.

Adolescent↗
PubMed1992

Bioavailability of methionine-hydroxy-analog free acid and S-methyl-methionine in the growing rat.

The biological utilization of DL-methionine (MET), DL-methionine-hydroxy-analog and DL-S-methyl-methionine-sulphonium-chloride (SMM) was tested in rat growth assay. Weight gain, feed efficiency, protein efficiency ratio (PER), net protein ratio (NPR) and net protein utilization (NPU) were applied as criteria. A test diet containing soybean meal as sole protein source was fortified with MET, MHA or SMM at 1.5 and 3.0 g/kg levels, respectively. All fortifications had a significant (p < 0.05) positive influence on weight gain, feed conversion and protein utilization. SMM showed the highest activity. MET and MHA were almost equally well utilized at 3.0 g/kg fortification level, however MHA proved slightly less efficient at 1.5 g/kg level than MET.

Animal Feed↗
PubMed1992

Dietary factors influencing protein utilization: a review.

Utilization of dietary protein depends not only on the amino acid composition and the digestibility of the protein itself, but also upon the level of protein, feed intake, energy, fibre, and other constituents in the feed. On the other hand, the animal species, sex, age and health status may also play an important role. A deeper understanding of these factors helps to utilize feedstuffs as a protein source more efficiently.

Animal Feed↗
PubMed1991

Experience with the Peponen capsule in the management of benign prostatic hyperplasia.

Sixty patients in Stages I and II of benign prostatic hyperplasia were treated with Peponen capsule. Out of them 26 took the drug for 10 months, 22 for at least 7, and 12 for at least 4 months. The daily dosage was 3 x 2 capsules in the first month and 3 x 1 capsule for the rest of the time. On the ground of urodynamic test results and changes in subjective complaints, more than 80% of the patients experienced improvement. The therapy intensified the uroflow, appeased dysuria, the difficult and painful discharge, and reduced the frequency of nocturnal urination.

Humans↗
PubMed1990

Damages to feed proteins and their nutritional consequences: a review.

The consequences of heat processing of feeds for sterilization and to destroy antinutritive substances can be beneficial as well as detrimental. Damages to feed proteins may be primarily explained by complex reactions between proteins and carbohydrates, by interactions between protein molecules and by oxidation. The chemical mechanisms and nutritional consequences of these reactions are reviewed.

Animal Feed↗
PubMed1990

Optimizing protein quality of mixtures of blood meal, feather meal and bone meal.

The protein quality of two- or three-component mixtures of blood meal, feather meal and bone meal was characterized by amino acid scores and rat net protein utilization (NPU) values. A graphic method designed to find optimum levels of the limiting essential amino acids in the mixtures was suitable for predicting the optimum of NPU values determined by feeding rats with diets having 10% crude protein. The protein quality of mixtures of blood meal, feather meal and bone meal showed an optimum if blood meal constituted 60% of the protein content of the mixtures; however, poor feed intake and growth data were obtained.

Animal Feed↗
PubMed1989

The value of crude protein content and in vitro pepsin digestibility of abattoir by-product meals in the prediction of their available protein content.

Amino acid composition of meat-and-bone meals, poultry by-product meals, blood meals, bone meals and feather meals showed characteristic differences. Meat-and-bone meals and blood meals had surplus in lysine, whereas poultry by-product meals and feather meals were relatively rich in cystine. Blood meals had high levels of branched-chain amino acids as compared to isoleucine. In vitro pepsin digestibility of meat-and-bone meals (79.9 +/- 17.7%; n = 24) and blood meals (95.8 +/- 4.2%; n = 11) was found to be higher than that of poultry by-product meals (65.3 +/- 7.7%; n = 14) or feather meals (44.7 +/- 9.2%; n = 16). Pepsin digestibility of poultry by-product meals showed a significant negative correlation with crude protein content (r = -0.73; P less than 0.05; n = 14). However, in vitro pepsin digestibility of poultry by-product meals as well as meat-and-bone meals, blood meals and feather meals, showed insignificant correlations with NPU indices as well as with available crude protein contents of the meals. The NPU values of meat-and-bone meals for rats (29.9 +/- 11.7; n = 100) were lower than those of poultry by-product meals (52.1 +/- 7.1; n = 14). The NPU values of blood meals (6.4 +/- 5.6; n = 11) and feather meals (23.5 +/- 10.0; n = 16), determined as sole sources of protein, were low and they did not elicit weight gain in rats. The available crude protein content of poultry by-product meals (34.3 g/100 g +/- 3.6; n = 14) was higher than that of meat-and-bone meals (17.0 g/100 g +/- 7.3; n = 100).(ABSTRACT TRUNCATED AT 250 WORDS)

Abattoirs↗
PubMed1989

Possible involvement of the dopaminergic system in the mode of action of the potential antidepressant trazium esilate.

Trazium esilate (EGYT-3615) is structurally an as-triazino isoquinolinium salt which showed considerable activity in pharmacological tests characteristic for antidepressants (antagonism of tetrabenazine, potentiation of yohimbine, behavioral despair). The compound exhibited minimal sedative effect. Some findings suggest that it influences the central dopaminergic system. The drug potentiated actions of amphetamine such as stereotypy and hypermotility. It differentially blocked the hypothermic and the stereotypy inducing action of apomorphine. Trazium esilate also inhibited the cataleptic state provoked by bulbocapnine in mice. In higher dose it decreased the plasma prolactin level in rats. The compound potentiated the effect of norepinephrine on isolated vas deferens of the rat. Trazium esilate is a weak displacer on a1-, a2- and D2-receptors, however, it induced a2-receptor desenzitization after repeated treatment. It had no influence on rat brain cortical noradrenaline and striatal dopamine release evoked by high K+ concentration, but it increased the spontaneous dopamine outflow in rat striatum. The compound also elevated the striatal dopamine and DOPAC levels both after acute and chronic treatment.

Animals↗
PubMed1989

Chemical composition and vitamin B content of abattoir by-product meals.

Chemical composition of meat-and-bone meals (n = 22), poultry by-product meals (n = 12), blood meals (n = 6), bone meals (n = 4) and feather meals (n = 8) indicated a slight degree of overdrying. Crude fat and ash contents were within the acceptable limits. Mineral elements of bones were determinative in the element pattern of meat-and-bone meals as indicated by the significant correlations between Ca, P and Mg. Crude protein was in negative regression and correlation with crude ash content (r = -0.81; P less than 0.001). This was more pronounced when the data were expressed in fatless dry matter (r = -0.94; P less than 0.001). Crude protein also showed significant negative correlations with Ca, P and Mg contents, offering the possibility to predict their levels from nitrogen content. Meat-and-bone meals and poultry by-product meals were relatively rich sources of riboflavin, niacin, pantothenic acid and biotin, whereas their pyridoxine and thiamine contents were low. Blood meals, bone meals and feather meals were found to be negligible vitamin B sources. Vitamin B and crude protein content of abattoir by-product meals showed uncertain correlations.

Abattoirs↗
PubMed1989

Traditional and new concepts in protein evaluation of feeds: a review.

The purpose of protein evaluation of a diet is to determine its value for meeting amino acid requirements of animals. The early recognition that proteins can be utilized by different efficiency rates has promoted extended research to reveal quality differences and their reasons. A brief historical overview is given in this review about the development of concepts and theories in protein evaluation. Recent developments have focused attention on determination of available quantities of essential amino acids. In vitro chemical assays and dye-binding procedures are relatively fast and provide data without access to animals, however they do not always correlate well with biological estimates. Enzymic digestion methods and microbiological assays for prediction of availability of essential amino acids have the potential for serial determination in quality control, however they are constrained by a lack of information about the availability of peptides liberated and utilized during in vivo digestion of proteins. Animal growth assays and balance experiments can provide valuable estimates of available quantities of essential amino acids. However, the interpretation of data is complicated by the many factors affecting in vivo protein utilization, by the endogenous amino acid excretion and the effects of microflora of the alimentary tract. The search for reliable assays remains a worthwhile objective also in the future.

Amino Acids↗