Periconceptional undernutrition affects in utero methyltransferase expression and steroid hormone concentrations in uterine flushings and blood plasma during the peri-implantation period in domestic pigs.

Female undernutrition during early pregnancy may affect the physiological pattern of genomic DNA methylation. We hypothesised that in utero DNA methylation may be impaired in females fed a restrictive diet in early pregnancy. In this study we evaluated whether poor maternal nutritional status, induced by applying a restricted diet during the peri-conceptional period, may influence: (1) the potential for in utero DNA methylation, expressed as changes in the mRNA expression and protein abundance of methyltransferases: DNA methyltransferase 1 (DNMT1) and DNMT3a in the endometrium and the myometrium, (2) the intrauterine microenvironment, measured as oestradiol 17ß (E2) and progesterone (P4) concentrations in uterine flushings and (3) plasma concentration of E2 and P4 during the peri-implantation period. Our results indicate that maternal peri-conceptional undernutrition affects maintenance and de novo DNA methylation in the endometrium, de novo methylation in the myometrium and a results in a decrease in intrauterine E2 concentration during the peri-implantation period. The intrauterine concentration of P4 and plasma concentrations of E2 and P4 did not change. These findings suggest that undernutrition during the earliest period of pregnancy, and perhaps the pre-pregnancy period, may create changes in epigenetic mechanisms in the uterus and intrauterine milieu of E2 during the peri-implantation period.

Meat quality, some hematological and biochemical parameters in the blood of finishing pigs assigned to different carcass conformation classes in the SEUROP system.

The results of laboratory analyses, including the proximate composition, physicochemical and sensory properties of meat from the studied pigs, point to its high processing suitability and eating quality. Hematological indicators in the blood of the analyzed animal groups were within the reference ranges, excluding MCHC levels which were somewhat elevated. Significant differences were observed in Hb, HCT, MCV, MCH, MCHC and WBC values, subject to the meat content of the carcass. Biochemical parameters such as glucose concentrations, ALT and AST activity levels varied considerably between groups, and average ALT values somewhat exceeded the norm for the species. These results, including significant variations in selected parameters, can probably be attributed to homeostatic changes in pigs during intensive growth.

Slaughter value, meat quality, creatine kinase activity and cortisol levels in the blood serum of growing-finishing pigs slaughtered immediately after transport and after a rest period.

The experimental materials comprised 44 hybrid [female (Polish Large White x Polish Landrace) x male Duroc] growing-finishing pigs. The animals were randomly divided into two groups: 24 pigs were slaughtered immediately after transport and 20 pigs were slaughtered after a 24-hour rest period in the lairage. The meat content of pork carcasses, carcass dressing percentage, the proximate chemical composition, physicochemical and sensory properties of meat and shear force values were determined. Serum creatine kinase activity and cortisol levels were determined in blood samples collected before transport and during carcass bleeding. Pigs slaughtered immediately after transport, compared with those slaughtered after a 24-hour rest period, were characterized by a higher meat content of the carcass and a higher carcass dressing percentage. Pre-slaughter handling had no effect on pork quality. The incidence of normal-quality meat, partially PSE (pale, soft, exudative) meat and PSE meat was similar in both groups. Chemical analysis showed that the content of dry matter, total protein, fat and minerals in meat was comparable in both groups. As regards the functional properties of the pork, samples from the carcasses of pigs that had rested before slaughter had a higher contribution of the red color component. Meat from pigs slaughtered immediately after transport had more desirable sensory properties. Pre-slaughter resting had a significant effect on those analyzed physiological parameters which were found to be good indicators of pre-slaughter stress. Serum creatine kinase activity and cortisol levels were higher in blood samples collected after transport (during carcass bleeding) than in samples collected before transport, pointing to a strong stress response of animals to pre-slaughter treatment. The decrease in serum cortisol levels in blood samples collected during bleeding from the carcasses of pigs slaughtered after a 24-hour rest period, compared with samples collected from animals slaughtered immediately after transport, suggests that rest before slaughter alleviated stress induced by pre-slaughter handling operations.

[House fly development after chitin biosynthesis inhibitor application to eggs]. / Rozwój muchy domowej poddanej dzialaniu inhibitorów biosyntezy chityny w stadium jaj.

Nine asymmetrically substituted ureas were bioassayed against house-fly (Musca domestica L.) eggs. The compounds included benzoylaryl urea derivatives, shown in Table I, (compounds 1 and 3-8) and benzoylheteroaryl ureas (2 and 9) which previously revealed effective inhibition of metamorphosis and reproduction when applied in food to the larvae and adults. The benzoyl moiety of the compounds comprise 2,6-disubstituted benzene ring with fluorine atoms (6-9), chlorine atoms (1-2) or fluorine and chlorine atoms (3-5), respectively. The majority of the compounds include aniline derivatives (1, 3-8), except the two containing pyridine ring (2) or pyridone-2 system (9). The eggs of house fly Musca domestica L. (some hours after they were laid) were put on a piece of cloth impregnated with acetone solution of tested compounds in concentrations 0.1 and 0.01%. The hatching of larvae and the later phases of development were observed. From the tested compounds one (no 8 in tab. II) decreased and delayed the hatching, two compounds (no 1 and 4 in tab. II) affected the later stages of development: the number of pupae and adults were decreased.

New proctolin analogs modified in position 3 of peptide chain--synthesis and their biological evaluation.

Six proctolin analogs modified in position 3 of peptide chain such as Arg-Tyr-X-Pro-Thr where X = Gly (1), Val (2), Pro (3), Thr (4), Acp (1-aminocyclopentane-1-carboxylic acid residue) (5), and Ach (1-aminocyclohexane-1-carboxylic acid residue) (6) were synthesized by liquid-phase method. Biological effects of the pentapeptides (1-6) were examined in cardiostimulatory test in vitro in respect to two insect species: American cockroach (Periplaneta americana L.) and yellow mealworm (Tenebrio molitor L.). Results thus obtained pointed out that the presence of L-leucine in the position 3 of proctolin skeleton plays important role in its cardiotropic activity in insects.

Insect peptide hormones, an overview of the present literature.

A comprehensive overview of the recent state of the art of insect peptide hormones with chemical structures is presented. An increased interest in insect neuropeptides and dynamic development of that research area has been influenced by a rapid improvement of instrumentation necessary for isolation and structural characterization. Several research teams have studied the relationships between biological properties of insect and vertebrate peptide hormones. Thus hormones from the AKH family can be considered glucagon counterparts, whereas the myotropic hormones such as proctolin and Lem-PK (LPK) are a substance P equivalent. Insect melanization hormones Bom-MRCH in their structural characteristics and properties resemble those of mammal MSH, and leucosulfakinins Lem-SK-I and -II show some similarities with gastrin II and cholecystokinin. Bombyxin-II (Bom-PTTH-II) reveals a structural homology with human insulin and similar biological properties to adenocorticotropic mammal hormone. Allatostatin (Dip-JHS-I) may be compared to somatostatin as it can be inferred from the observations that this peptide modulates JH secretion in cockroach, Blattella germanica. Determination of the primary structure of eclosion hormones Mas-EH and Bom-EH-II as well as the amino acid sequence of allatotropin and allatostatin is a significant contribution to the understanding of the molecular mechanisms of metamorphosis and insect development.

[Review of the methods of control of pathogenetic arthropods of medical and veterinary importance]. / Przeglad metod zwalczania szkodliwych stawonogów, w tym o znaczeniu medycznym i weterynaryjnym.

Chemical and biological methods of the title arthropod pests control, during the past 1985-1989, have been reviewed. Among insecticides the chlorinated hydrocarbons, organophosphorous compounds, carbamates and particularly pyrethroids played still the outstanding role. Juvenoids, chitin synthesis inhibitors and semi-chemicals such as pheromones and feeding deterrents were discussed. WHO recommended insecticides for mosquito, housefly, cockroach Pharaoh's ant, flea, and bedbug control in Poland have been listed. Some biological methods applied against agricultural pests were mentioned.

[Effect of selected compounds from the group of chitin synthesis inhibitors on insects of sanitary importance]. / Wplyw wybranych zwiazków z grupy inhibitorów syntezy chityny na owady o znaczeniu sanitarnym.

The effect of three aryl and heteroaryl dichlorobenzoylurea compounds as insect chitin inhibitors on sanitary important insects were investigated. These compounds were given insects: larvae and adults flies (Musca domestica) and cockroaches (Blattella germanica) with food. The best results on flies were after exposition to AG-6 and on cockroaches to AG-5. AG-6 complete inhibited metamorphosis after exposition of larvae and after exposition of adults in generation F1. No mature cockroaches from larvae exposed to AG-5, no hatching from cocoons lied by treated adults were observed.

Further studies on proctolin analogues modified in position 2 of the peptide chain and their influence on heart-beat frequency of insects.

Seven proctolin analogues (I-VII) modified in position 2 of the peptide chain by Phe (p-guanidino) (I), Phe (p-OEt) (II), Tyr (3'-NH2) (III), Tyr (3'-NO2) (IV), Afb (p-OH) (V) (Afb = 3-amino-4-phenyl-L-butyric acid), Afb (p-NH2) (VI), Afb (p-NO2) (VII), and the tetrapeptide Tyr (3'-NH2)-Leu-Pro-Thr (VIII) were synthesized by the classic liquid-phase method. The biological effects of the peptides were investigated in cardioexcitatory tests on two insect species, the cockroach Periplaneta americana L., and the yellow mealworm, Tenebrio molitor L. Within physiological concentrations (10(-9)-10(-7) M) peptides II, III, and IV stimulated the heart action of P. americana like proctolin itself. Under identical conditions, in the case of T. molitor, only peptide III showed cardiostimulatory properties, whereas other compounds (including II and IV) were inactive at concentrations up to 10(-7) M. Results reported here reflect, with reference to the analogues I-VII, selective recognition of receptors on myocardium of both insect species. The tetrapeptide VIII revealed a weak deacceleratory effect on P. americana and T. molitor heart action.

Role of guanidine group at the N-terminal proctolin chain in cardioexcitatory effects in insects.

Six proctolin analogues (I-VI) modified in position 1 of the peptide chain by the following amino acids: homo-Arg, Gac, Gav, Gap, Phe (p-guanidino) and Orn, were synthesized by conventional liquid phase method. The myotropic activity of the obtained peptides was investigated in cardioexcitatory test on two insect species, cockroach, Periplaneta americana L., and yellow mealworm, Tenebrio molitor.

[Effectiveness of 2,6-dihalogenbenzoyl urea derivatives as potential inhibitors of chitin biosynthesis regarding the house fly Musca domestica L. and cockroach Blatella germanica L]. / Efektywnosc pochodnych 2,6-dihalogenobenzoiloarylomocznikowych potencjalnych inhibitorów biosyntezy chityny w stosunku do much domowych musca domestica L. i prusaków blattella germanica L.

The biological activity was determined of 20 compounds from the group of asymmetrically substituted urea derivatives. They were derivatives of 1-(hetero)-aryl-3(2,6-dichlorobenzoyl)urea, compounds in Table 1, (1-12) which represented three groups of compounds: a) monochlorine or trifluoromethyl derivatives of benzene, b) monomethyl-substituted 2-pyridine derivatives, c) a derivative of 5-bromo-3-pyridine, and symmetrical derivates (Table 2 compounds 1-8) 2.2; 3.3; 4.4 groupings: a) N-(2,6-dichlorobenzoyl)urea derivatives, and b) N-(2-chloro-6-fluorobenzoyl)urea derivatives. The experiment was carried out on larvae and adult forms of M. domestica L. and Blatella germanica L. The tested substances were administered in food to the insects. Of the tested compounds complete inhibition of the development of flies was caused by the compound designated with the symbol AG 6. Compounds AG 13, AG 15 and AG 17 given to larvae inhibited the development of the insects by 33 to 100% acting mainly in later phases of the development (pupation). Compound AG 5 was found to be a very strong inhibitor of the development of cockroaches acting on larvae and adult females Of 800 tested larvae exposed to concentrations 0.001 to 1% none reached the adult phase. The exposed adult females formed cocoons but no larvae hatched from them.