Anti-HEV seroprevalence and rate of viremia in a German cohort of dogs, cats, and horses.

Hepatitis E virus (HEV) genotype 3 infections in Germany are mainly transmitted zoonotically through the consumption of swine meat. Furthermore, there is evidence that pets might come into contact with HEV, but the relevance of companion animals as possible sources of HEV transmission in Germany still needs to be defined. A monitoring study was therefore carried out on dogs, cats, and horses from Germany. In total 365 serum samples from pets (124 dogs, 119 cats, and 122 horses) were tested for HEV by PCR and for anti-HEV antibodies by a commercial ELISA. The HEV seroprevalence determined by the sero-assay varied significantly between dogs (10%), cats (6%), and horses (2%). Liver injury-related enzymes, alanine transaminase (ALT), and aspartate transaminase (AST) showed no differences between HEV-positive or negative animals. None of the pet serum samples tested positive for PCR. This serological study suggests that dogs and cats are significantly exposed to HEV in Germany, while horses are of minor relevance.

The complex of recombinant human insulin-like growth factor-I (rhIGF-I) and its binding protein-5 (IGFBP-5) induces local bone formation in murine calvariae and in rat cortical bone after local or systemic administration.

The influence of recombinant human insulin-like growth factor-I (rhIGF-I), its binding protein-5 (IGFBP-5) or their equimolar complexes on calvarial osteogenesis was investigated by quantitative radiography and histomorphometry after local administration to adult mice or mature rats. The systemic effects of these proteins were investigated in aged Sprague-Dawley rats with regard to their ability to prevent or restore bone mass in ovariectomy induced osteopenia as assessed by radiography, dual-energy X-ray absorptiometry (DEXA) analyses, peripheral computerized tomography (pQCT) and mineral analyses after daily s.c. administration for 3 or 8 weeks following a bone depletion period of 8 weeks. Bone mass of murine calvariae was significantly increased in a dose-dependent manner by the complex 7 days after discontinuation of local administration for 19 days in mice, whereas IGF-I alone expressed only weak effects. IGFBP-5 alone was ineffective in this respect. In the same model, only the complex had a weak osteogenetic potential in 7 week or 5 month old rats. Systemic long-term treatment with the complex of rhIGF-I/IGFBP-5 (2.0/7.6 mg/kg/day, s.c.) for 8 weeks resulted in significantly increased cortical thickness, area and mineral density in femoral midshaft or tibial metaphysis suggesting periosteal bone formation. This was obviously related to increased muscle strength since these effects were parallelled by increased body weight. No effect on trabecular bone occurred as demonstrated by site-specific analyses (vertebrae, proximal tibia) using DEXA, pQCT and radiography. This selective action of rhIGF-I/IGFBP-5 on periosteal bone formation is unique for an IGFBP. Femoral ash and calcium content, both corrected for tissue volume, increased slightly. However, when the increase in cortical thickness and bone mass was corrected for bone size, the effects are nearly abolished, suggesting an additional effect of bone growth. This potential deserves further evaluation in order to differentiate between effects on cortical bone via muscle strength and lack of efficacy on trabecular bone balance.

Effects of angiotensin II on bone cells in vitro.

Other than its known effects on the cardiovascular system, angiotensin II (Ang II) stimulates cell growth in several cell types. In this study, we examined whether it also might affect bone cell metabolism. Ang II stimulated DNA and collagen synthesis and decreased alkaline phosphatase (AP) activity in bone cell populations derived from the periosteum of fetal rat calvariae. Similar effects of Ang II were observed on human adult bone cells obtained by collagenase digestion from trabecular bone. Clonal cell analysis, autoradiographic studies, and receptor subtype analysis suggested the presence of specific Ang II receptor subtype 1 (AT1) binding sites on AP+ osteoblastic precursor cells. Ang II had no direct effects on osteoblastic cells with a mature phenotype, but paracrine effects of Ang II on mature osteoblasts could be observed upon coculture with Ang II-responsive bone cell populations. Because Ang II is known to be locally generated by endothelial cells, Ang II might play an important role in coordinating capillary cell growth and osteoblastic bone formation during bone remodeling.

Effect of 2,3,7,8-tetrachlorodibenzo-P-dioxin (TCDD) on the hepatic stellate cell population in the rat.

TCDD inhibits the normal accumulation of vitamin A in the hepatic stellate cells, which constitute the main storage site for vitamin A. In this study we investigated if the reduced capacity of stellate cells to store vitamin A could be due to cell transformation or cytotoxicity. Livers from rats exposed to TCDD were immunohistochemically stained for markers of normal and transformed stellate cells. The results show that the TCDD-induced inhibition of hepatic vitamin A accumulation is neither due to a reduction in the number of stellate cells nor to transformation of the cells.

The efficacy of using prelay and early-lay rations for brown-egg pullets.

Experiments were conducted using two brown-egg strains to determine whether additional calcium or CP is required by these pullets prior to sexual maturity (prelay) and whether increased CP during the early part of production (early lay) would improve overall performance. In Experiment 1, the prelay treatments were arranged at a 2 x 3 factorial arrangement with two levels of CP (15 or 17%) and three levels of calcium (.9, 1.8, or 3.5%) and given to the pullets from 18 to 20 wk of age. From 20 to 26 wk of age, pullets were given either a 17 or 19% CP ration with 3.5% calcium, resulting in a total of 12 treatments. There were no significant effects of the prelay or early-lay rations on eggs per hen housed, hen-day percentage production (HDP), or feed efficiency. Egg weight was significantly improved using the 17% prelay ration at 26, 28, and 31 wk of age, but adversely affected by the higher levels of CP in the early-lay ration at 28 and 31 wk of age. Increasing calcium in the prelay ration had only minimal effects on egg size distribution. Experiment 2 consisted of a 3 x 2 factorial arrangement of treatments with three levels of prelay CP (15, 17, or 19%) and two levels of early-lay CP (17 or 19%) and given to the pullets from 18 to 20 to 41 wk of age, respectively. There was a significant improvement in HDP from 30 to 41 wk of age using the 19% CP prelay ration. Egg size distribution was not significantly affected by either the prelay or the early-lay rations at 35 wk of age.

Research note: influence of ahemeral light:dark cycles on egg traits in brown egg pullets.

Brown egg pullets (DeKalb Sex-Sal) were subjected to an ahemeral lighting program to determine their response in terms of egg traits. All birds were reared on a conventional lighting program of 10 h light (L):14 h dark (D) to 16 wk. At 16 wk, all birds received a schedule of 11L:13D followed by a weekly 1-h increase in photoperiod to 14L:10D at 19 wk. Control treatment (CON) birds were continued on this schedule. Ahemeral treatment (AHM) birds were given a 28-h schedule 14L:14D at 23 wk that was continued to 28 wk, then returned to a 24-h cycle of 14L:10D. Shell weight responded quickly to the ahemeral treatment and showed a significant (P less than .05) increase during the 2nd 28-h cycle. Shell thickness and total egg weight showed significant increases on the 3rd cycle; albumen weight showed an increase on Cycle 4, and yolk weight increased significantly only on the 8th cycle. When AHM treatment birds were returned to a conventional cycle (14L:10D) at 28 wk, the total weight remained significantly higher (P less than .05) as late as Cycle 6.

Effect of ahemeral light:dark cycles on egg production in early photostimulated brown-egg pullets.

A laying trial was conducted to determine the effect of an ahemeral lighting program on early photostimulated brown-egg pullets (DeKalb Sex-Sal). All birds received 24 h of light/day (24L:0D) to 3 days of age followed by 8 h of light (8L:16D) to 8 wk of age. From 8 to 16 wk the birds received 10 h of light daily. At 16 wk, the control group (CON) received 11 h of light and 13 h of darkness (11L:13D) followed by a weekly 1-h increase in photoperiod to 14L:10D at 19 wk, which was maintained for the duration of the trial (59 wk of age). Birds on the ahemeral (AHM) schedule were exposed to a 26-h schedule of 11L:15D at 16 wk with a weekly 1-h increase in the photoperiod to 14L:12D at 19 wk. The AHM schedule (14L:12D) was maintained from Weeks 19 to 30 at which time birds were returned to a 24-h cycle of 14L:10D and kept on this schedule for the remainder of the trial. Egg weight was significantly increased by the AHM treatment for 27 to 30 wk; however, there was no cumulative (Weeks 19 to 59) effect on egg weight. Percentages of eggs per hen per day (%HDP) were significantly reduced by the AHM treatment for the periods 23 to 26 wk and 31 to 34 wk. This reduction caused a significant cumulative effect on %HDP (68.9 for CON versus 66.2 for AHM).(ABSTRACT TRUNCATED AT 250 WORDS)

Haemodynamic profile of an inhibitor of phosphodiesterase III, adibendan (BM 14.478): comparison with nitroprusside and dobutamine in conscious dogs.

1. This study was performed to investigate whether cardiac positive inotropic as well as peripheral vasodilator properties of adibendan contribute to its overall haemodynamic profile in conscious dogs. 2. Haemodynamic measurements were carried out in conscious chronically instrumented dogs after administration of adibendan, sodium nitroprusside or dobutamine. 3. The cardiovascular changes induced by adibendan (0.01 and 0.03 mg kg-1) resembled those of dobutamine (1.0-4.0 micrograms kg-1 min-1): left ventricular dP/dt60 (LV dP/dt60), stroke volume (SV) and cardiac output (CO) increased to a similar extent, but mean arterial pressure (MAP) and heart rate (HR) remained unchanged. 4. In contrast to dobutamine, higher doses of adibendan (0.1-1.0 mg kg-1) decreased MAP and LVEDP. These effects were of a similar magnitude to those observed following nitroprusside administration (0.5-12.5 micrograms kg-1 min-1). In contrast to nitroprusside, adibendan still showed additional effects on LV dP/dt60 and CO. 5. From these results, it is concluded that both the peripheral vasodilator and the cardiac positive inotropic action of adibendan contribute to its overall haemodynamic profile.

Nonsteroidal cardiotonics. 3. New 4,5-dihydro-6-(1H-indol-5-yl)pyridazin-3(2H)-ones and related compounds with positive inotropic activities.

A series of substituted indolyldihydropyridazinones and related compounds 1-18 were synthesized and evaluated for positive inotropic activity. In rats, most of these indole derivatives produced a dose-related increase in myocardial contractility with little effect on heart rate and blood pressure. Compound 13, 4,5-dihydro-5-methyl-6-(2-pyridin-4-yl-1H-indol-5-yl)pyrazin-3(2H) -one (BM 50.0430), was further investigated in cats. The increase in contractility in this animal model was not mediated via stimulation of beta-adrenergic receptors. After oral administration of 1 mg/kg to conscious dogs, compound 13 and pimobendan were still active after 6.5 h. However, the cardiotonic effect of 13 was at least 2-fold that of pimobendan after this period of time. The structural requirements necessary for optimal cardiotonic activity within this novel class of indole derivatives are a heterocyclic aromatic ring in position 2, a hydrogen or a methyl group in position 3, and a dihydropyridazinone ring system in position 5 of the indole.

Pharmacological characteristics of the stereoisomers of carvedilol.

The racemic compound carvedilol possesses two complementary pharmacological effects, vasodilation and beta-blockade. The R- and S-enantiomers of carvedilol and the racemate were investigated with respect to the beta-blocking, vasodilating, and hypotensive actions. In agreement with results obtained with other beta-blockers, only the S-enantiomer of carvedilol exerts beta-blocking effects. In contrast, no substantial difference between the enantiomers could be seen with respect to alpha-blockade. The greater hypotensive activity of S-carvedilol may be attributed to beta-blockade, which inhibits counter-regulatory mechanisms provoked by vasodilation. From these results it is concluded that there is a rationale for using carvedilol as the racemate. Using the S-enantiomer would lead to relatively strong beta-blockade with only a weak vasodilating effect. The R-enantiomer alone would act only as a hypotensive agent without beta-blockade.

In vitro investigations on a new positive inotropic and vasodilating agent (BM 14.478) that increases myocardial cyclic AMP content and myofibrillar calcium sensitivity.

BM 14.478 (7,7-dimethyl-2-(4-pyridyl)-6,7-dihydro-3H,5H pyrrolo[2,3-f]benz-imidazol-6-one) was investigated in several in vitro experiments to elucidate its positive inotropic and vasodilating efficacy and its mode of action. A direct positive inotropic action was achieved in papillary muscles (10(-6) to 5 X 10(-4) M) and electrically driven atria (10(-8) to 5 X 10(-4) M) from guinea pig hearts. The effect was not affected by propranolol, cimetidine, or tetrodotoxin, but diminished by carbachol. The effect of isoprenaline was amplified by threshold concentrations of BM 14.478 (10(-6) M). There was only a slight intrinsic chronotropic activity in spontaneously beating guinea pig atria. Atrial cyclic AMP (cAMP) was increased from 1.46 +/- 0.06 to 1.97 +/- 0.03 pmol/mg wet wt, at 3 X 10(-6) M. This might be due to an inhibition of cardiac phosphodiesterase(s) (PDE). IC50 of bovine PDE was 7.2 X 10(-5) M (5.4 X 10(-5) M to 9.7 X 10(-5) M). BM 14.478 shortened the duration of transmembrane action potential (90% repol.) by 8% and increased the Vmax of slow action potentials by 32% at 3 X 10(-4) M. In skinned porcine heart muscle fibers an increase in calcium-activated force up to 43 +/- 7% was observed (10(-7) to 10(-4) M). Rat aortas were relaxed by about 75% maximally (10(-7) to 10(-4) M). It is concluded that BM 14.478 is a potent inotropic drug which acts via an increase in myocardial cAMP content and in calcium sensitivity of contractile proteins.

Ca2+-sensitizing effect of BM 14.478 on skinned cardiac muscle fibres of guinea-pig papillary muscle.

A concentration-dependent increase in force development was obtained with BM 14.478 (10(-9)-5 X 10(-4) M) in skinned fibres of guinea-pig papillary muscles. Guinea-pig papillary muscles are standard preparations for evaluating inotropic effects and they were also used in the present case for evaluating the positive inotropic effect of BM 14.478. We therefore conclude that a marked calcium-sensitizing effect contributes to the positive inotropic effect obtained with BM 14.478 even at very low concentrations.

Effect of vitamin E and synthetic antioxidants on the survival rate of mercury-poisoned Japanese quail.

The effect of vitamin E and the synthetic antioxidants, 6-ethyoxy,1,2-dihydro 2,2,4-trimethylquinoline (ethoxyquin), 2,6 bis(1,1 dimethyethyl)-4-methylphenol (BHT), N,N-diphenyl-p-phenylene diamine (DPPD), bis-(diethyl thiocarbamoyl) disulfide (Antabuse), and 2 tertiary-butyl-4-methoxyphenol (BHA) on organic mercury-induced mortality was investigated in Japanese quail. When the synthetic antioxidants, ethoxyquin, BHT, and Antabuse were fed at 1% of the diet, they induced mortality. Ethoxyquin was less toxic in combination with mercury (Hg) than when it or mercury was given alone. Of the antioxidants tested at .5% of the diet, only Antabuse was toxic as shown by increased mortality. At .5% of the diet, both ethoxyquin and DPPD reduced mortality associated with organic Hg poisoning. Neither BHA nor BHT had any effect in reducing Hg toxicity. In fact, mortality from organic Hg was greater when organic Hg was given in combination with .5% BHT than when given alone. Vitamin E was equal or superior to all synthetic antioxidants tested in alleviating the toxicity of organic Hg poisoning. The cause of observed antioxidant protection during organic Hg stress is not known but the protection may result from the ability to scavenge free radicals generated by induction of in vivo peroxidation by the Hg compound.

The 14CO2 breath test: facilities and limitations of a rapid and noninvasive method for in vivo evaluation of modified hepatic cytochrome P-450--a critique.

By means of the breath test technique the cascade from O-demethylations to CO2 was investigated after pretreatment of mice with warfarin, phenobarbital, cobaltous chloride, sodium vanadate and metyrapone. It was the intention to examine the validity of the technique with respect to cytochrome P-450 activity. Therefore three different radioactive labeled substrates, i.e., hydrogen carbonate, formate and xenobiotics, were applied at three different levels of the one-carbon pathway and were utilized to demonstrate possible interference of the modifiers with the sequence from O-demethylation to CO2. Real in vivo information about a modified cytochrome P-450 system can be obtained using model substrates carefully selected with regard to the type of expected modification of the monooxygenase system. In addition, a parallel monitoring of the consecutive reaction sequence by measuring the conversion of formate to CO2 is necessary in order to guarantee the validity of the in vivo technique in visualizing the activity of the hepatic monooxygenase system.

Effects of early maturation of brown egg-type pullets, flock uniformity, layer protein level, and cage design on egg production, egg size, and egg quality.

Eight-week-old Harco Sex-Link pullets were assigned to four growing regimens. Feed was restricted to Group 1. The birds reached an average weight of 1.52 kg at 20 weeks of age and were then light stimulated. Group 2 received the same ration ad lib and reached an average weight of 1.64 kg at 16 weeks. At this age they were light stimulated. Birds in Groups 3 and 4 were separated into two weight classes at 8 weeks of age. Those below the median weight received an 18% protein grower ration and those above the median weight a 16% ration. Group 3 birds were grown similarly to Group 1; Group 4 birds were grown similarly to Group 2. At housing, each group was equally divided and given either a 17 or 19% protein layer ration. Two cage designs (standard and reverse) were used and each treatment combination was equally represented. Ad lib-fed, early-housed pullets reached 1.64 kg at 16 weeks of age, but they did not come into production until 19.4 weeks of age. Hen-day percent production (HDP) was significantly less than for the late-housed pullets. Feed per dozen eggs was not affected by the early housing, but early-housed pullets laid significantly smaller eggs and feed per gram egg was significantly increased. Hens in reverse cages on a 19% protein layer ration laid the largest eggs in weight and size. Although early housing had a detrimental effect on average egg weight, it appeared possible to manipulate egg weight and size distribution through a combination of cage design and layer protein. Birds grouped by body weight at 8 weeks had higher uniformity, but this trait was not correlated with egg numbers or size. Moreover, housing body weights were not significantly correlated with egg size, suggesting factors other than body weight were responsible for the smaller eggs from early-housed pullets.

The effect of pelleting the layer ration on egg size in early-housed brown-egg-type layers.

Harco Sex-Link pullets (n = 360) were reared in cages and given a 15% protein grower ration. At 17 weeks of age, half the birds were transferred to laying cages and the photoperiod was increased to 13 hr for the first week and to 15 hr thereafter. The remaining birds were continued in the growing facility on 8 hr of light until 19 weeks when lights were increased to 13 hr daily. These birds were transferred to the laying cages at 20 weeks of age where they received 15 hr of light. At 2% production, all birds were fed a 17% protein layer diet in either a mash or pelleted form. Neither egg production nor feed efficiency was affected by age at housing or the physical form of the ration. Early-lighted pullets produced a greater percentage of small and medium-sized eggs. Egg size distribution was not affected by the physical form of the ration

Effects of early maturation, layer protein level, and methionine concentration on production performance of brown-egg-type pullets.

Three hundred and sixty 17-week-old Harco Sex Link pullets were transferred to laying cages and received 13 hr of light daily for the first week followed by 15 hr the second and subsequent weeks. A second group of 360 pullets remained in the growing facility on 8 hr of light until 19 weeks of age when the light was increased to 13 hr. At 20 weeks these birds were transferred to the laying facility where they received 15 hr of light daily for the duration of the experiment. A 15% protein grower ration was fed until daily production of each group reached 2%, at which time the diets were changed to either a 17 or 19% protein layer ration, each supplemented with DL-methionine so as to contain .3 or .4% total methionine. Early housed pullets averaged 140.4 days at first egg whereas late housed reached sexual maturity at 149 days. The initial increase in egg production by the early housed pullets was followed by a more rapid decline and overall, from housing to 66 weeks, equivalent egg numbers were produced. The early housed pullets were less efficient than the late housed birds due in part to their larger body mass. The greater percentage of small and medium-sized eggs produced by the early housed birds was not influenced by increasing the concentration of protein or methionine in the layer ration.

Induction of liver cytochrome P-450 in mice by warfarin. Comparison of warfarin-, phenobarbitone-, and cobalt-induced hepatic microsomal protein patterns by PAGE after partial purification on octyl-sepharose CL-4B.

A rapid method is presented to separate mouse liver cytochrome P-450 from other components of the microsomal monooxygenase system and to increase specific activity by hydrophobic interaction chromatography on Octyl-Sepharose CL-4B by a factor of between 3.8 and 5.3. In addition it is shown that varieties of cytochrome P-450 can be separated from each other by Octyl-Sepharose CL-4B. After oral applications of 120 mg/kg warfarin once daily for three days SDS-PAGE analysis of the partially purified cytochrome P-450 fraction revealed a protein pattern in the 50 Kd region that is practically indistinguishable from that after conventional phenobarbitone pretreatment. On the other hand, cobalt pretreatment results in a different pattern that is distinguished from that of normals as well as from that of phenobarbitone- and warfarin-pretreated mice. From these results in conjunction with the previous finding of increased drug metabolic activity after warfarin pretreatment it is concluded that warfarin elicits phenobarbitone-like induction of the hepatic monooxygenases in mice.

Radioisomers of scoparone (6,7-dimethoxycoumarin) as a tool for in vivo differentiation of various hepatic monooxygenase inducers in mice using the breath test technique.

The oxidative removal of two different methyl groups from scoparone by a cytochrome P-450-mediated reaction proceeds with greater velocity for the 6-methyl group than for the 7-methyl group. In vivo experiments in mice were carried out with the two respective radioisomers [6-methyl-14C]scoparone and [7-methyl-14C]scoparone. The consecutive administration of the scoparone to the same animal is followed by collecting the 14CO2 exhaled (breath test). The maximal exhalation rate, measured 4 min after i.p. administration of the substrates, is four times greater for [6-methyl-14C]scoparone than for the [7-methyl-14C]scoparone. The total recovery of radioactivity in the whole animal (except skin) including the exhaled 14CO2 is 86% for [7-methyl-14C]scoparone and 84% for [6-methyl-14C]scoparone. Further analysis shows that the proportion of radioactivity found in various excretory routes is different; however, in the case of the poorly exhaled [7-methyl-14C]scoparone, almost twice as much radioactivity is found in bile and urine than for the more rapidly exhaled [6-methyl-14C]scoparone, whereas liver and other organs show little changes. Pretreatment of animals with various inducers, such as phenobarbital, 3-methylcholanthrene, warfarin and cobaltous chloride, characteristically affects the ratio of the two demethylations of scoparone. In the case of warfarin pretreatment, the ratio of the 6- to 7-demethylation is elevated to nearly 6, after cobaltous chloride the ratio is lowered to 2.8, whereas phenobarbital and 3-methylcholanthrene have no effect. These results may provide possibilities of noninvasive in vivo recognition of the inductive state of a pretreated animal.