Structure-activity relationship study of alkynyl ether insecticide synergists and the development of MB-599 (verbutin)

Structure-activity relationships of aryl alkynyl synergists of the general formula of Ar-Q-R, where Q represents a bridging structure, were studied using a standardised testing system and Relative Potency values. Ethers, esters, oxime ethers, amides and amines were prepared and evaluated. The length of the R-alkynyl chain, the role of the bridge and the substitution of the aromatic ring were examined systematically. The most potent compounds possessed an aromatic ring connected via a bridge of three atoms to an alkynyl chain, forming together a linear side-chain of six atoms. Several highly potent compounds were synthesised of which one (MB-599; proposed common name verbutin) was selected for development as a selective insecticide synergist in crop protection. Its high potential at practical insecticide:synergist ratios makes possible the reduction of the total amount of insect-control chemicals applied, and its use as an additive to produce new formulations of existing insecticides makes it highly advantageous in resistance management, giving a new tool to sustain the effectiveness of a wide range of insecticides. A product containing a (1+1) mixture of verbutin and beta-cypermethrin was launched in Hungary in 2002.     

Identification of marker alleles linked to fire blight resistance QTLs in apple genotypes

Molecular marker analysis can be an effective tool when searching for new fire blight resistance donors. It can speed up the breeding process as well, even though many of the available markers linked to fire blight resistance QTLs have not yet been tested by screening a large number of cultivars. The aim of this study was to search for alternate sources of the three major QTLs of fire blight resistance; FBF7, FB_MR5 and FB_E, as well as to test the efficiency of some markers linked to minor QTLs. Altogether, nine primer pairs were used on 77 genotypes including new Hungarian cultivars and old apple cultivars from the Carpathian basin. Several marker alleles of FB resistance QTLs have been detected in the screened genotypes, most importantly the alleles coupling with FB_MR5 in the old cultivars ‘Kéresi muskotály’, ‘Szabadkai szercsika’ and ‘Batul’. We propose these cultivars as the first available resistance donors of FB_MR5 instead of the crabapple Malus × robusta 5. The results also bring new information regarding the resistance alleles of new Hungarian cultivars and selections.     

Immunogene expression in head kidney and spleen of common carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.) following thermal stress and challenge with Gram-negative bacterium, <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis>

To evaluate the effect of thermal and microbial stress on the immune response of common carp (Cyprinus carpio L.), relative mRNA expression level of pro-inflammatory cytokines [tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1β] and other genes related to immune or stress response [inducible nitric oxide synthase (iNOS), heat shock protein 70 (Hsp70), superoxide dismutase one (SOD1), and glucocorticoid receptor (GR)] was measured by quantitative PCR (qPCR). In addition, total protein and total immunoglobulin level in blood plasma of experimental common carp was also assayed. All the above parameters were estimated 24 h post-challenge with Gram-negative bacterium, Aeromonas hydrophila. Common carp (54.89?±?6.90 g) were initially exposed to 20 °C (control group) and 30 °C (thermal stress group) water temperature for 30 days, followed by experimental challenge with 2.29?×?10⁸ colony forming unit/mL (CFU/mL; LD₅₀ dose) of A. hydrophila. Exposure of fish to thermal stress and subsequently challenge with A. hydrophila significantly (P?<?0.05) increases the IL-1β mRNA expression in head kidney and spleen of common carp by ~?39.94 and ~?4.11-fold, respectively. However, TNF-α mRNA expression in spleen decreased ~?5.63-fold in control fish challenged with A. hydrophila. Thermal stress and challenge with bacterium suppresses the iNOS and GR mRNA expression in spleen of common carp. Moreover, significant (P?<?0.05) increase in total protein content of blood plasma (~?43 mg/g) was evident in fish exposed to thermal stress and challenged with A. hydrophila. In conclusion, our study highlights the importance of elevated temperature stress and microbial infection in differential regulation of expression of several immunogenes in common carp.     

A comparison of the effect of tiamulin hydrogen fumarate and tylosin tartrate on mycoplasmas of ruminants and some animal ureaplasmas

The in vitro efficacy of tiamulin was compared to that of tylosin against 7 bovine, 7 ovine and 3 caprine mycoplasma strains isolated from various organs and belonging to different species, as well as 7 ureaplasma strains cultured from cattle, sheep, swine, chickens and turkeys. The minimal mycoplasmacidal concentrations of tiamulin varied between 0.01 and 10.0 μg ml^?1, while tylosin proved to be active in concentrations of 0.5 and 100.0 μg ml^?1. Five of mycoplasma strains showed identical sensitivities to both antibiotics while all other strains, including the ureaplasmas, were sensitive to tiamulin at concentrations 5–5000-times lower than tylosin.     

Detection of urease-negative Bordetella bronchiseptica from the field

Four urease-negative Bordetella bronchiseptica isolates originating from pigs were examined by phenotypic and molecular methods. The phenotypic properties of the isolates were in harmony with the data of the literature, except for the lack of urease activity in conventional tube test, API 20 NE and Diatabs? assays. Using genotypic methods, the urease-negative isolates did not differ from the urease-positive reference strain. They were positive in species-specific and ureC PCR, and all strains showed uniform bands in PCR-RFLP studies of flaA genes. The reason for the lack of urease activity, a characteristic considered species specific for B. bronchiseptica, needs to be studied further. The finding underlines the significance of genotyping when the phenotypic identification of B. bronchiseptica seems questionable.     

Oestrogens in the mammalian brain: from conception to adulthood--a review

Environmental and plant oestrogens have been identified as compounds that when ingested, disrupt the physiological pathways of endogenous oestrogen actions and thus, act as agonists or antagonists of oestrogen. Although the risks of exposure to exogenous oestrogens (ExEs) are subject to scientific debate, the question of how ExE exposure affects the central nervous system remains to be answered. We attempt to summarise the mechanisms of oestrogenic effects in the central nervous tissue with the purpose to highlight the avenues potentially used by ExEs. The genomic and rapid, non-genomic cellular pathways activated by oestrogen are listed and discussed together with the best known interneuronal mechanisms of oestrogenic effects. Because the effects of oestrogen on the brain seem to be age dependent, we also found it necessary to put the age-dependent oestrogenic effects in parallel to their intra- and intercellular mechanisms of action. Finally, considering the practical risks of human ExE exposure, we briefly discuss the human significance of this matter. We believe this short review of the topic became necessary because recent data suggest new fields and pathways for endogenous oestrogen actions and have generated the concern that the hidden exposure of humans and domestic animal species to ExEs may also exert its beneficial and/or adverse effects through these avenues.     

Comparative studies on nectar from two self-fertile and two self-sterile cultivars of quince (Cydonia oblonga Mill.) and their attractiveness to honeybees

Summary

Cross-pollination is of primary importance for quince (Cydonia oblonga), whose flowers reward pollinators with pollen and nectar. Characteristics of the nectar from two self-fertile (SF) and two self-sterile (SS) cultivars of quince were compared in a 3-year study, in order to establish if the two fertility groups differed from each other in terms of nectar production and/or insect attraction. The volume of nectar secreted per flower per day was measured using calibrated capillaries. The concentrations of nectar sugars were determined using a hand-held refractometer. The composition of nectar sugars was analysed using thin layer chromatography and densitometry. The quantity and quality of the nectar varied between years, cultivars, and fertility types. The volumes of nectar ranged from 0.40 – 5.30 µl flower^–1 d^–1 over the 3 years. The concentrations of sugars in the nectar produced flower^–1 d^–1 averaged ≥ 20% (w/w) in all cultivars, and ranged from 21.80 – 35.60% (w/w) over the 3 years. Significantly lower volumes of nectar were measured in the SF cultivars than in the SS cultivars in both years of the study. However, the concentrations of sugars in the nectar were not significantly lower in the SF group. The total sugar content of nectar varied between 160.59 – 347.65 mg ml^–1. The main sugar component in the nectar was sucrose, followed by glucose and fructose. Differences in the composition of nectar sugars could not be correlated with the two fertility groups. Our data showed that, although certain properties of their nectar make SS cultivars more attractive to honeybees than SF cultivars, members of the latter group can also attract sufficient numbers of bees to carry out cross-pollination, which is beneficial to both fertility types of C. oblonga.     

Effectiveness of dietary vitamin supplementation to the performance of common carp (Cyprinus carpio L.) larvae in intensive rearing condition

Study of enrichment of different vitamins (C, B₁, B₆ and E) in common carp larvae through 4 weeks feeding in recirculation system was carried out. For this purpose, procedure for enrichment of Artemia nauplii with different vitamins was developed and investigated the effectiveness in larvae nutrition. The habituation of larvae to dry feeds was done using supplemented dry diets with the same vitamins. To study the effect of vitamins in young fish, the most common stress situation was planned for carp nursed fries, which occurs during transportation. Levels of vitamins and parameters of immune response in mucus were monitored before and after stress situation. At the end of the feeding trials using enriched Artemia nauplii, level of vitamin B₁, B₆ and C were increased in the body of fish, but remained on similar level or decreased after dry feeding period. Therefore, we concluded that Artemia is a good delivery vector of these vitamins. While handling stress, vitamin C and E concentration was decreased and sparing effect of antioxidant vitamins was confirmed in groups supplemented with both vitamins. Vitamin B₁ was consumed intensively during the stress, vigorously in groups without supplementation. Contrary to this, vitamin B₆ level increased in stress condition in group without supplementations. The levels of immunoglobulins in mucus were increased in all treated groups independently of treatment. Our results confirm that carp larvae reared in tank condition needs sufficient amount of vitamins C, B₁ and B₆ supplements to protect them from the mild handling stress.     

The neonatal Fc receptor (FcRn) is expressed in the bovine lung

In neonatal calves, maternal immunoglobulin (Ig) is transferred into respiratory secretion which contributes to protection against pathogens. The early predominance of IgG1 in respiratory tract secretions is progressively reduced in favor of IgA by age but in the lower, bronchoalveolar system secreted IgG remains the dominant secreted Ig even in adulthood. The trans-epithelial transport of secretory IgA into mucosal secretions is carried out by the polymeric Ig receptor. However, the mechanism by which IgG crosses epithelial cells to provide defense on mucosal surfaces is still unknown. In order to investigate the possibility that the neonatal Fc receptor, FcRn is involved in this transport we have first analyzed the localization of this receptor in the upper and lower respiratory tracts. Consistent with the in situ hybridization data, immunohistochemistry showed undetectable expression in the tracheal epithelial cells, relatively weak expression in epithelial cells of the bronchi, apparent staining those lining the bronchioli and randomly scattered signal over the alveolar tissue. The bovine FcRn may thus play a role in IgG transport across mucosal epithelial barriers as a trafficking receptor and ensure IgG predominance in the lower respiratory tract.     

Apricot aphid,Myzus mumecola (Matsumura), a new and important pest of apricot in Hungary

Journal of Plant Diseases and Protection - Apricot aphid, Myzus mumecola (Matsumura) (Homoptera: Aphididae), was recorded as a new pest of apricot in Hungary in the spring of 2020. Identification...