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Biomedical subjects

M Beyer

Publications and source records attributed to M Beyer.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Dependence of gross energy, digestive energy and metabolizable energy of feed and the energy disposition on the content of digestible nutrients in relation to starch and sugar. The progress of energetic feed evaluation. 1. Results from studies on swine].

On the basis of an analysis of energy metabolism measurements on adult pigs, fed on 92 ratios with very heterogeneous nutrient composition, the following prediction equations for gross energy (y1), digestible (y2) and metabolizable energy (y3) as well as for energy deposition effect of ratios (y) (kJ) are presented: y1 = 23.6z1 + 39.8z2 + 17.3z3 + 16.0z4 + 18.9z5 y2 = 23.6x1 + 39.8x2 + 17.3x3 + 16.0x4 + 17.2x5 y3 = 20.5x1 + 39.8x2 + 17.3x3 + 16.0x4 + 17.0x5 y = 11.0x1 + 34.0x2 + 12.7x3 + 11.6x4 + 5.0x7 + (12.0-0.14(80-x6))(x5-x7) [table: see text]

Animal Feed↗
PubMed1993

[Dependence of gross energy, digestible and metabolizable energy of feed and the energy onset on the content of digestible nutrients in regard to starch and sugar. A contribution to the further development of energetic feed evaluation. 2. Results from studies of cattle].

On the basis of an analysis of energy metabolism measurements on adult cattle (oxen), fed on 110 rations with very heterogeneous nutrient composition, the following prediction equations for gross energy (y1), digestible (y2) and metabolizable energy (y3) as well as for energy deposition effect of rations (y) (kJ) are presented: y1 = 23.6z1 + 34.0z2 + 17.3z3 + 16.0z4 + 19.1z5 y2 = 23.6x1 + 34.0x2 + 17.3x3 + 16.0x4 + 18.0x5 y3 = 17.3x1 + 34.0x2 + 15.9x3 + 15.1x4 + 15.4x5 y = (6.5x + 26.6x2 + 10.1x3 + 7.5x4 + 8.9x5) (-0.5574 + 0.04050x6 - 0.0002633x6(2)) [table: see text]

Animal Feed↗
PubMed1993

[Effect of the starch sources barley, corn and potatoes and their ration portions on nutrient digestibility and energy utilization in ruminants. 3. Energy utilization in cattle].

With investigations on the influence of different starch origins (barley, maize and raw potatoes) and different portions of the starch origins in the rations (50, 25 and 10% of the net energy fat, cattle (NEFr) content of the rations) on the energy utilization of rations a contribution was made to the development of the energetic feed evaluation within Rostock NEF-system. The experiments were carried out with fattened oxen using the methods of total metabolism technique and duodenal passage measurement by means of reentrant fistula. The nutrition levels amounted to 1.7 and 1.1 of energy maintenance requirement. The utilization of metabolizable energy for deposition of the 9 rations-including 3 variants of starch origins barley, maize and raw potatoes with parts in the rations of 50, 25 and 10%--was measured as 65, 61 and 59%, 61, 60 and 58% as well as 59, 61 and 55%. The energy maintenance requirement amounted to 526 kJ ME/kg LM 0.75.d. The gradations of energy utilization are caused by the connection between energy concentration and utilization of rations in ruminants. With comparable parts of the rations the different starch sources had no relevant influence on the energy utilization of the rations. Despite a wide range of starch plus water soluble carbohydrates (WSC) intake between 896 and 3426 g/animal.d no correlation between the kind of digestion (fermentative or enzymatic) of starch and WSC and the energy utilization of the rations was measurable, because the part of the ruminal digestion amounted to 86.0 and 97.2%. The result presented for the energy and nitrogen metabolism measurements are in good agreement with results of former experiments with 92 rations.

Animal Feed↗
PubMed1993

[The energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 1. Experimental plan and results concerning the live weight development of pregnant, non-pregnant and lactating sows and the reproductive performance during gestation and lactation].

The aim of the experiments was to work out new results for a factorial derivation of energy and protein requirement. The experiments were carried out according to a 3 x 3 factorial experimental plan with 3 variants of litter number (1, 2 and 4, age of sows) and 3 variants of energy supply (120, 100 and 80% of the norm of pregnancy, continued in lactation with 80, 100 and 120%). Methods of the indirect calorimetry and the slaughtering technique were used. The mean cumulative live weight changes of the sows for the 9 experimental variants amounted from 13.1 to 63.2 kg for the 115 days of pregnancy and from -17.0 to 6.8 kg for the first 26 days of lactation. The chosen variation of energy supply of pregnant and lactating sows had no relevant effect on the reproductive performances, measured by litter size, weight of conception products, litter weight at birth and the quantity of milk per sow and day respectively. In comparison with the sows of litter number 1 the sows of litter number 2 and 4 had higher litter weights at birth and higher milk quantities.

Amino Acids↗
PubMed1993

[The energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 2. Chemical composition and energy content of the animal bodies of pregnant, non-pregnant and lactating sows].

The influence of litter number (1, 2 and 4, age of sows) as well as gestation and lactation stage of sows on the chemical composition and on the quantities of protein and fat of their bodies was investigated. The slaughter of 46 pregnant, 18 non-pregnant and 17 lactating sows were carried out at the 1st, 56th, 84th, 98th, 105th and 113th day of gestation, 113th day of experiment (non-pregnant sows) and 26th day of lactation. The results were related to the sows' energy supply (120, 100 and 80%) with equal supply of protein, vitamins and minerals. Within the tested litter numbers the chemical composition of the bodies was nearly constant during the whole time of gestation and lactation. A good agreement existed for the chemical composition of the sows' bodies of litter number 1 and 2. In comparison to them the bodies of litter number 4 contained more protein and less fat per kg dry matter. The quantities of body protein and fat increased in the gestation and decreased in the lactation period, in each case the quantities of fat exceeded than the quantities of protein. The quantities of body protein increased with higher litter number. The quantities of body fat increased from litter number 1 to 2 and were nearly equal in the sows of litter numbers 1 and 4. Within one litter number the amounts of body protein and fat attained the same level in pregnant, non-pregnant and lactating sows.

Animals↗
PubMed1993

[The effect of starch sources barley, maize and potatoes and their ration portions on the nutrient digestibility and energy utilization in ruminants. 4. Nitrogen metabolism in the rumen].

In 9 experimental periods on four adult bulls (LW 550 kg) fitted with re-entrant cannulae in the proximal duodenum isoenergetic rations were used on feeding level 1.7 with ground barley, ground maize or fresh potatoes as starch sources. The net energy parts of these concentrates in the ration amounted to 50, 25 and 10%. 50 to 80% of the ration DM consisted of dried grass and about 10% of sugar beet pulp. The dried grass supplied on an average 87, 79 and 62% of the feed crude protein. The intake of DM was 7.74 +/- 0.42 (mean +/- SD) kg/d. The energetic efficiency of microbial N synthesis in the rumen (g N/kg organic matter true fermented in the rumen, TFOM) was averaged 16.4 with a range of 10.6 to 21.4. The microbial efficiency achieved a maximum when the ratio of nitrogen-free extract to crude fibre in the diet was 1.7 and 2.1 with barley, 1.8 with potatoes and 2.1 and 3.3 with corn as starch source. Changes in the microbial efficiency were positively correlated with the rate of passage of non-microbial organic matter from the rumen (g/d) and with the duodenal flow rate (kg digesta/kg DM intake). The relation to the rate of carbohydrate fermentation in the rumen (in %) and to the amount of TFOM (g/d) was negative. The duodenal flow of microbial N and non-ammonia N (g/d) correlated negatively with the organic matter apparently fermented in the rumen (AFOM) and positively with the non AFOM. The amino acid (AA) profile of the duodenal protein was affected by the starch source. It was concluded that the metabolism of nitrogen in the forestomachs of cattle is affected by the source of starch and the ratio of forage to concentrate. There exists a relationship between both factors. The net synthesis of microbial protein in the rumen is not only the result of substrate fermentation. The passage of non-AFOM from the rumen significantly affects the energetic efficiency of microbial nitrogen synthesis and the duodenal supply of AA.

Amino Acids↗
PubMed1993

Investigations on the influence of Clenbuterol and recombinant porcine somatotropin on nitrogen and energy metabolism in growing pigs.

The effect of Clenbuterol and recombinant porcine Somatotropin (rpST) on the N and energy metabolism was tested by means of the respiration trial technique and compared with a control. In one experiment Clenbuterol was given per os on the nutrition level of three times energy maintenance requirement and in two experiments on the nutrition level 3.2 and 2.4 times energy maintenance requirement, rpST was injected s.c. The live weight gain of the treated animals was 9% (Clenbuterol), 18 and 24% (rpST) higher than that of the controls, protein energy deposition was 21% (Clenbuterol), 45 and 46% (rpST) higher and fat energy deposition was 14% (Clenbuterol), 33 and 37% (rpST) lower than that of the controls.

Aging↗
PubMed1993

[Energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 3. Chemical composition and energy content of the animal body fractions as well as portions of the animal body fractions of empty body of nonpregnant, pregnant and lactating sows].

The study is based on the results obtained from the slaughter of 5 sows on the first day of pregnancy and the first day of the experiment respectively (pregnant and non-pregnant sows resp.), of 43 pregnant sows on the 56th, 84th, 98th, 105th and 113rd day of gestation as well as 17 lactating sows on the 26th day of lactation. The animal bodies of pregnant sows were divided in 15 fractions and those of non-pregnant and lactating sows in 12 fractions. The investigations were carried out with 3 x 3 variants of litter number (1, 2, 4) and energy supply (120, 100, 80% of requirement recommendation). The chemical composition and the energy content of the animal body fractions as well as their relative portions of the empty body were largely constant during the course of gestation with the exception of the reproductive organs and the conception products. The physiological stage of lactation connected with limited mobilization of body reserves resulted in a reduction in fat content of some body fractions as well as a limited increase of the portions of body organs contrary to the portions of body tissues of the empty body. In comparison with sows of litter numbers 1 and 2 the sows of litter number 4 were characterized by higher portions of bones and meat, valuable parts as well as by smaller portions of depotfat and meat from head and belly of empty body. The raising of the energy supply of the pregnant sows increased the portion of the depotfat and decreased the portion of the meat, valuable parts of the empty body. The chemical composition of the reproductive organs and the conception products as well as the portions of these fractions of the empty body were influenced strongly from the course of the gestation and lactation resp. The portions of the reproductive organs and of the conception products are small (related to energy < or = 5.7 and < or = 2.6% resp.)

Abattoirs↗
PubMed1993

Patient selection for ICD treatment and peri-operative mortality.

In view of the reported high risks resulting from the implantation of a cardioverter (ICD) and our own experience, we retrospectively evaluated the patients who received an ICD at our institution, so as to predict factors that could lead to a high peri-operative risk. The patients were divided into three groups according to their diagnoses and the surgical procedure. Group I: 10 patients with non-ischaemic cardiomyopathy, age 53.9 +/- 14.0 years, ejection fraction (EF) 33.1 +/- 11.8; group II:13 patients with coronary artery disease (CAD), diffuse arteriosclerosis, age 60.0 +/- 6.8 years, EF 31.4 +/- 9.1%; group III:12 patients, age 61.9 +/- 9.4 years, EF 41.2 +/- 8.6, CAD, concomitant bypass grafting. In cases of cardiomyopathy, cardiac complications (30%) were reversible by adequate drug therapy. However, five patients in group II (38.5%) died from cardiac complications, mainly frequent arrhythmias and subsequent pump failure. In group III no peri-operative complications occurred. Therefore the high mortality (overall 13.2%) in our series was exclusively due to patients suffering from severe CAD and unsuitable for revascularization. Considering the high risk after ICD placement, primary heart transplantation might be the better procedure in younger patients with end-stage CAD.

Adult↗
PubMed1993

Effect of phenylephrine bolus administration on global left ventricular function in patients with coronary artery disease and patients with valvular aortic stenosis.

BACKGROUND: Although phenylephrine bolus administration is frequently used to increase coronary perfusion pressure in patients with coronary artery disease or valvular aortic stenosis, there are no data describing its effect on left ventricular function (LVF). METHODS: Twenty patients scheduled for elective coronary artery bypass grafting (group 1) and 18 patients scheduled for elective aortic valve replacement (group 2) entered the study. The effect of phenylephrine was compared with that of norepinephrine in those patients who developed a defined degree of arterial hypotension under general anesthesia. These patients were randomized to receive an initial bolus of either phenylephrine (1 micrograms/kg) or norepinephrine (0.05 micrograms/kg) followed by a bolus of the other drug after arterial pressure and heart rate (HR) had returned to baseline. Transesophageal echocardiography was used to evaluate LVF. Arterial pressure, HR, ejection time, and LV diameter, area, and wall thickness were recorded immediately before and for 3 min after bolus administration. Fractional diameter shortening, fractional area change, mean heart rate corrected velocity of circumferential fiber shortening (mVcfc), and LV meridional end-systolic wall stress (ESWS) were calculated. RESULTS: Both substances effectively restored arterial pressure in both groups. However, in group 1, phenylephrine administration resulted in a reduction of fractional area change from 0.51 (median) to 0.39 (P = 0.0007) and a reduction of mVcfc from 1.16 to 0.61 circ/s (P = 0.0001). End-systolic wall stress increased from 98 to 186 10(3) dyne-cm-2 (P = 0.0001). Administration of norepinephrine to group 1 and administration of either substance to the group 2 patients did not cause any significant changes of LVF. CONCLUSIONS: The results indicate that phenylephrine given as an intravenous bolus to patients with CAD anesthetized with fentanyl causes a transient impairment of LV global function and that phenylephrine bolus administration is well tolerated in patients with valvular aortic stenosis.

Aged↗
PubMed1993

Factors affecting the serum free thyroxine levels in hospitalized chronic geriatric patients.

OBJECTIVE: Determination of whether nonthyroidal factors affect the diagnostic value of free thyroxine estimation in geriatric patients. DESIGN: Survey. PARTICIPANTS: A convenience sample of 381 non-selected, chronic, hospitalized geriatric patients over 60 years of age (I = relatively good health; II = relatively poor health; III = bad health; subgroups "sine therapia," ie, patients receiving no drugs that affect FT4) and 180 20-40 year old healthy persons. MEASUREMENTS: Thyrotropin-releasing hormone test; thyrotropin (TSH); free thyroxine (FT4, measured in part by two parallel methods) estimation in a screening study; and thyroxine-binding globulin and thyroxine-binding-inhibitor activity measurements. RESULTS: The normal FT4 ranges of the euthyroid geriatric (n = 210) and healthy young groups were similar. In the "sine therapia" euthyroid patients, FT4 decreased with age but increase with the severity of illness. High FT4 levels with non-suppressed TSH were more frequent in patients in poor and bad health. (I = 6/112; II = 14/140; III = 13/74; P < 0.01). The serum thyroxine-binding-inhibitor activity of euthyroid geriatric patients correlated with the severity of their clinical state (I = 6.22 +/- 5.65 (13); II = 7.40 +/- 4.33 (23); III = 10.04 +/- 5.50 (16) micrograms merthiolate equivalent/microL; ANOVA with log-transformed values: F(2.51) = 3.50, P < 0.05). The mean FT4 was higher in 36 heparin-treated patients (22.81 +/- 4.67 pmol/L) than in the 193 "sine therapia" patients (19.03 +/- 4.23 pmol/L; -P < 0.001). In a convenience subsample of 240 patients, a weak inverse correlation was found between FT4 and the thyroxine-binding globulin (r = -0.14, P < 0.02). Only 5/11 patients with low free thyroxine had hypothyroidism, while 11/46 patients with elevated free thyroxine had hyperthyroidism. CONCLUSIONS: There is no need to modify the normal free thyroxine range for hospitalized geriatric patients. Clinical condition, drug treatment, and, to a lesser extent, age are factors that significantly affect the diagnostic value of FT4 in hospitalized chronic geriatric patients, decreasing the specificity of the test in diagnosing clinical hyper- and hypothyroidism.

Activities of Daily Living↗
PubMed1993

[Myocardial revascularization with a free skeletal muscle transplant--a functional analysis of angiogenesis].

In order to evaluate the functional aspect of myocardial neovascularization after grafting a free skeletal muscle flap onto the heart in the dog with an arterial anastomosis to the internal mammary artery (IMA), a gradual occlusion of the left anterior descending coronary (LAD) was induced. This was achieved implanting an Ameroidconstrictor on the LAD, that due to its hygroscopical material induces a gradual coronary occlusion. The occlusion of the LAD was angiographically confirmed in vivo. In one dog the selective angiographical demonstration of the IMA anastomosed to the graft was achieved. This showed retrograde filling of the LAD occluded by the Ameroidconstrictor. These findings were confirmed in all dogs by a microvascular corrosion cast preparation of the vasculature induced from the graft, that was differentiated from the coronaries by a different coloured casting material. The occluded LAD was filled in all preparations by the casting material applied into the IMA. Thus, grafting of a free skeletal muscle flap anastomosed to the IMA onto the dog's heart produces a functional myocardial neovascularization.

Animals↗
PubMed1993

[The diagnostic value of standard ECG methods, the cold-pressure test and Valsalva maneuver in idiopathic QT syndrome].

The idiopathic Long QT Syndrome is an infrequently occurring disorder. Affected patients usually show ECG alterations and are prone to syncope and sudden arrhythmic cardiac death. Adequate therapy with beta-blocking drugs may significantly improve the prognosis of affected patients. The early and precise diagnosis of the disorder therefore has major prognostic impact. This paper reports the diagnostic significance of standard ECG, exercise stress testing, ambulatory ECG monitoring, cold pressor test and Valsalva maneuver in 14 patients with Long QT Syndrome. The results were compared with those obtained in 14 healthy age matched volunteers. QTc duration was significantly longer in patients with Long QT Syndrome during standard 12-lead ECG at rest (489 +/- 55 ms versus < vs. > 412 +/- 25 ms, p < 0.005), exercise stress test (490 +/- 39 ms vs. 409 +/- 18 ms, p < 0.001), cold pressor test (512 +/- 45 ms vs. 407 +/- 19 ms, p < 0.001), Valsalva maneuver (497 +/- 49 vs. 407 +/- 18 ms, p < 0.001), minimal heart rate during 24-h of ambulatory ECG monitoring (482 +/- 69 ms vs. 402 +/- 22 ms, p < 0.01) and maximal heart rate during Holter monitoring (460 +/- 47 ms vs. 411 +/- 27 ms, p < 0.005). Four of 14 patients with Long QT Syndrome had pathological findings during ambulatory ECG monitoring (two patients showed short episodes of asymptomatic torsade de pointes tachycardia, one patient had an intermittent SA-Block, and one patient showed T-wave alternans). All healthy volunteers had normal ambulatory ECG recordings (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Experimental selective myocardial infarction in the dog without open-chest-surgery.

In 16 dogs, a selective myocardial infarction (MI) was experimentally provoked without open-chest-surgery by means of microspheres (MS) injected into a Judkins-catheter positioned into the left anterior descending coronary (LAD) under fluoroscopy. This was shown by ECG-abnormalities, increase of the serum-enzymes of myocardial necrosis, decrease of left ventricular end diastolic pressure (LVEDP), wedge pressure, and cardiac output. After 5 weeks, thoracotomy showed a myocardial infarction limited to the anterior wall of the heart, which was of subendocardial location and consisted of multiple zones of microinfarction. Histological examination of the corresponding area showed necrosis of myocardial muscle fibres.

Animals↗
PubMed1992

A microcorrosion cast study for analyzing a new method of indirect myocardial revascularization.

In order to study the process of angiogenesis a free skeletal muscle flap was transplanted onto the myocardium of the dog. A microvascular anastomosis with the internal mammary artery (IMA) provided the blood flow to the free graft. In 6 dogs, a myocardial infarction of the anterior wall was induced in order to produce a tissue injury. Four weeks later the skeletal muscle flap was transplanted onto the area of infarction in two dogs with its pars anterior in contact with the heart. In two dogs, the muscle was grafted with its pars posterior, i.e. the muscle fascia between the heart and the graft. In two other dogs, the flap was transplanted with its pars anterior in contact with the heart onto a healthy myocardium. Two animals with infarction were left as controls. Eighteen weeks later a microcorrosion cast was prepared from the hearts with the muscle flap. This evidenced neoangiogenesis in the heart only after transplantation of the graft with its pars anterior onto the myocardium whether it was ischemic or not. The intact muscle fascia, though, inhibited sprouting of vessels. In the controls no angiogenic activity was noted. Results are discussed with regard to the probable origin of the neovessels.

Animals↗
PubMed1992

[The energy metabolism of growing swine in a live weight range of 10-50 kg. 3. Energy maintenance requirement of growing swine].

Investigations into the energy maintenance requirement yielded the following results: For the energy maintenance requirement (EMR) in dependence on live weight (LW) using the relation EMR = aLWb from 13 experiments, an exponent of the live weight of 0.647 +/- 0.054 (0.57 to 0.73) was found out. Increasing the protein content in the feed from approximately 17 to approximately 45% in 6 experiments lowered the energy maintenance requirements about 14, 4, 6, 2, 6 and 12% respectively. The animals' development had no influence on the difference. The amount of the energy maintenance requirement varied greatly between the experiments. Exclusively in the experiments with barrows, a lowest value of 634 and a highest value of 931 kJ metabolizable energy per kg LW0.62.d was measured. On average of 19 comparisons the energy maintenance requirement derived from growth and maintenance periods by means of regression analysis was significant (alpha = 0.05), about 4% higher than the energy maintenance requirement measured on maintenance level directly.

Animal Feed↗
PubMed1992

[The energetic utilization of rations with molasses, dried sugar beets, apple pectin and lucerne leaves by adult swine].

The energetic utilization of 6 rations with molasses, dried sugar beets, apple pectin and lucerne leaves was measured in 8 adult pigs by means of the respiration test technique. The energy digestibility of the rations ranged from 74 to 88%, the partial utilization of the metabolizable energy from 66 to 78%. From the results with apple pectin a mean energy deposition value of 7.2 +/- 12.5 kJ/g digestible pectin was derived. Taking into consideration results from previous recorded experiments and the high standard deviation for estimation of the energetic feed value as deposition effect of digestible pectin, 5 kJ/g are proposed.

Animal Feed↗