In vitro susceptibilities to fluoroquinolones in current and archived Mycoplasma gallisepticum and Mycoplasma synoviae isolates from meat-type turkeys     

Gerchman I  Lysnyansky I  Perk S  Levisohn S 《Veterinary microbiology》2008,131(3-4):266-276

Monitoring of susceptibility to antibiotics in field isolates of pathogenic avian mycoplasmas is important for appropriate choice of treatment. Our study compared in vitro susceptibility to enrofloxacin and difloxacin in recent (2005-2006) isolates of Mycoplasma gallisepticum and Mycoplasma synoviae from meat-type turkey flocks with archived (1997-2003) isolates and reference strains. Comparison of minimal inhibitory concentration (MIC) values determined by microtest, agar dilution and commercial Etest showed good agreement, but underscored the need for standardized methods for testing. Notably, while the commercial Etest was convenient and accurate for determining MICs for enrofloxacin in the range 0.002-0.094mug/ml, the endpoint of inhibition for M. gallisepticum and M. synoviae strains with MIC values >/=1.0mug/ml could not be determined. A decrease in susceptibility to both fluoroquinolones was detected in archived strains but to a greater degree in recent isolates, most of which had MICs above the NCCLS susceptibility breakpoint for these antibiotics (相似文献   

Comparative Analysis of the Functional Properties of Films Based on Carrageenans,Chitosan, and Their Polyelectrolyte Complexes     

Aleksandra V. Volod&#x;ko  Viktoriya N. Davydova  Valentina A. Petrova  Dmitry P. Romanov  Evgeniya A. Pimenova  Irina M. Yermak 《Marine drugs》2021,19(12)

The influence of the structural features of carrageenan on the functional properties of the films was studied. The carrageenans and chitosan films, as well as three-layer films containing a polyelectrolyte complex (PEC) of the two, were prepared. The X-ray diffractograms of carrageenan films reflected its amorphous structure, whereas chitosan and three-layer films were characterized by strong reflection in the regions of 20° and 15° angles, respectively. The SEM of the cross-sectional morphology showed dense packing of the chitosan film, as well as the layer-by-layer structure of different densities for the PEC. Among the tested samples, κ/β-carrageenan and chitosan films showed the highest tensile strength and maximum elongation. Films containing the drug substance echinochrome were obtained. Mucoadhesive properties were assessed as the ability of the films to swell on the mucous tissue and their erosion after contact with the mucosa. All studied films exhibited mucoadhesive properties. All studied films exhibited mucoadhesive properties which depended on the carrageenans structure. Multilayer films are stronger than single-layer carrageenan films due to PEC formation. The resulting puncture strength of the obtained films was comparable to that of commercial samples described in the literature.  相似文献   

Sex Specificity in Innate Immunity of Insect Larvae     

Irina Belousova  Sergey Pavlushin  Anna Subbotina  Natalya Rudneva  Vyacheslav Martemyanov 《Journal of insect science (Online)》2021,21(6)

The innate immunity of insects has been widely studied. Although the effect of sex on insect immunity has been extensively discussed, differences in immunity between the sexes of larvae insects remain largely unstudied. Studying larval sex differences in immunity may provide valuable information about the mechanisms underlying the insect immune system, which, in turn, can be valuable for the development and improvement of pest management. Here we compared the antibacterial activity in both the midgut tissue and cell-free hemolymph of Lymantria dispar L. (Lepidoptera: Erebidae) females and males at the larval stage without and after a challenge by entomopathogenic bacterium Bacillus thuringiensis Berliner. We also evaluated the sex-specific mortality of L. dispar induced by B. thuringiensis infection. We find that antibacterial activity in the midgut is activated by infection, but only in females. Thus, sex differences in immunity can have important effects even before sexual differentiation at adulthood.  相似文献   

Weak effects of farming practices corresponding to agricultural greening measures on farmland bird diversity in boreal landscapes     

Ekroos  Johan  Tiainen  Juha  Seimola  Tuomas  Herzon  Irina 《Landscape Ecology》2019,34(2):389-402

Context

The current Common Agricultural Policy (CAP) of the European Union includes three greening measures, which are partly intended to benefit farmland biodiversity. However, the relative biodiversity effects of the greening measures, including joint effects of landscape context, are not well understood.

Objectives

We studied the effects of increasing crop diversity, proportions of production grasslands and fallows, corresponding to CAP greening measures, on open farmland bird diversity, whilst controlling for the effects of distance to forests, field edge density and proportion of built-up areas.

Methods

We surveyed open farmland birds using territory mapping in Southern Finland. We modelled effects of greening measures and landscape structure on farmland birds (7642 territories) using generalised linear mixed models.

Results

Increasing proportions of grasslands increased farmland bird species richness and diversity in open farmland, whereas increasing proportions of fallows increased bird diversity. Increasing crop diversity benefited individual species, but not species richness or diversity. Increasing field edge densities consistently increased the species richness of all farmland species, in-field nesters and non-crop nesters, as well as total farmland bird diversity. The relative effect of edge density was much stronger compared to the three greening measures.

Conclusions

Our results show that promoting fallows and grasslands, in particular grazed grasslands and various types of semi-natural grasslands, has the highest potential to benefit farmland bird diversity. Maintaining or increasing field edge densities, currently not supported, seems to be of even more benefit. In open farmland, with little or no field edges, fallows and grasslands are particularly beneficial.

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The Biochemical Composition and Antioxidant Properties of Fucus vesiculosus from the Arctic Region     

Ekaterina D. Obluchinskaya  Olga N. Pozharitskaya  Denis V. Zakharov  Elena V. Flisyuk  Inna I. Terninko  Yulia E. Generalova  Irina E. Smekhova  Alexander N. Shikov 《Marine drugs》2022,20(3)

Fucus vesiculosus is one of the most prominent brown algae in the shallow waters of the seas of the Arctic region (Barents (BS), White (WS), Norwegian (NS), and Irminger (IS)). The aim of this study was to determine the biochemical composition of F. vesiculosus from the Arctic at different reproductive phases, and to evaluate the antioxidant properties of F. vesiculosus extracts. The amounts of monosaccharides, phlorotannins, flavonoids, and ash and the mineral composition significantly varied in the algae. A strong correlation was established between monosaccharide, phlorotannin, and flavonoid accumulation and water salinity (Pearson’s correlation coefficients r = −0.58, 0.83, and 0.44, respectively; p < 0.05). We noted a negative correlation between the antioxidant activity and the amount of the structural monosaccharides of fucoidan (r = −0.64). A positive correlation of phlorotannins and flavonoids with antioxidant power was confirmed for all samples. The ash accumulation was relatively lower in the sterile phase for the algae from the BS and WS. The correlation between the Metal Pollution Index (MPI) and the reproductive phases was medium with high fluctuation. Meanwhile, the MPI strongly correlated with the salinity and sampling site. The gradient of the MPI values across the sea was in the following ranking order: BS < WS < NS < IS. Taken together, and based on our data on the elemental contents of F. vesiculosus, we believe that this alga does not accumulate toxic doses of elements. Therefore, the Arctic F. vesiculosus could be safely used in food and drug development as a source of active biochemical compounds and as a source of dietary elements to cover the daily nutritional requirements of humans.  相似文献   

Effect of solid-state fermentation on the protein quality and volatile profile of pea and navy bean protein isolates     

Azita Khorsandi  Dai Shi  Andrea K. Stone  Aarti Bhagwat  Yuping Lu  Caishuang Xu  Prem Prakash Das  Brittany Polley  Leonid Akhov  Jessica Gerein  Xiumei Han  Pankaj Bhowmik  L. Irina Zaharia  James D. House  Nandhakishore Rajagopalan  Takuji Tanaka  Darren R. Korber  Michael T. Nickerson 《Cereal Chemistry》2024,101(1):131-143

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GH,IGF-I and GH receptors mRNA expression in response to growth impairment following a food deprivation period in individually housed cichlid fish Cichlasoma dimerus     

Tomás Horacio Delgadin  Daniela Irina Pérez Sirkin  María Paula Di Yorio  Silvia Eda Arranz  Paula Gabriela Vissio 《Fish physiology and biochemistry》2015,41(1):51-60

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Effects of different five-day progesterone-based fixed-time AI protocols on follicular/luteal dynamics and fertility in dairy cows     

Irina GARCIA-ISPIERTO  Fernando LóPEZ-GATIUS 《The Journal of reproduction and development》2014,60(6):426-432

This study compares in two experiments the responses of lactating dairy cows to four different progesterone-based protocols for fixed-time artificial insemination (FTAI) in terms of their effects on follicular/luteal dynamics and fertility. The protocols consisted of a progesterone intravaginal device fitted for five days, along with the administration of different combinations of gonadotropin releasing hormone, equine chorionic gonadotropin and a single or double dose (24 h apart) of prostaglandin F_2α. In Experiment I, the data were derived from 232 lactating cows. Binary logistic regression identified no effects of treatment on ovulation failure or multiple ovulation 10 days post artificial insemination (AI). Based on the odds ratio, the likelihood of ovulation failure was lower (by a factor of 0.1) in cows showing at least one corpus luteum (CL) upon treatment than in cows lacking a CL; repeat breeders (> 3 AI) and cows with multiple CLs at treatment showed lower (by a factor of 0.44) and higher (by a factor of 9.0) risks of multiple ovulation, respectively, than the remaining animals. In Experiment II, the data were derived from 5173 AIs. The independent variable treatment failed to affect the conception rate 28–34 days post AI, twin pregnancy or early fetal loss 58–64 days post AI. The results of this study demonstrate the efficacy of 5-day progesterone-based protocols for FTAI. All four protocols examined were able to induce ovulation in both cyclic and non-cyclic animals so that FTAI returned a similar pregnancy rate to spontaneous estrus. Our results suggest that the ovarian response and fertility resulting from each treatment are due more to the effect of ovarian structures at treatment than to the different combinations of hormones investigated.  相似文献   

Heterodimeric GTPase core of the SRP targeting complex     

Focia PJ  Shepotinovskaya IV  Seidler JA  Freymann DM 《Science (New York, N.Y.)》2004,303(5656):373-377

Two structurally homologous guanosine triphosphatase (GTPase) domains interact directly during signal recognition particle (SRP)-mediated cotranslational targeting of proteins to the membrane. The 2.05 angstrom structure of a complex of the NG GTPase domains of Ffh and FtsY reveals a remarkably symmetric heterodimer sequestering a composite active site that contains two bound nucleotides. The structure explains the coordinate activation of the two GTPases. Conformational changes coupled to formation of their extensive interface may function allosterically to signal formation of the targeting complex to the signal-sequence binding site and the translocon. We propose that the complex represents a molecular "latch" and that its disengagement is regulated by completion of assembly of the GTPase active site.  相似文献   

Nucleus accumbens D2/3 receptors predict trait impulsivity and cocaine reinforcement     

Dalley JW  Fryer TD  Brichard L  Robinson ES  Theobald DE  Lääne K  Peña Y  Murphy ER  Shah Y  Probst K  Abakumova I  Aigbirhio FI  Richards HK  Hong Y  Baron JC  Everitt BJ  Robbins TW 《Science (New York, N.Y.)》2007,315(5816):1267-1270

Stimulant addiction is often linked to excessive risk taking, sensation seeking, and impulsivity, but in ways that are poorly understood. We report here that a form of impulsivity in rats predicts high rates of intravenous cocaine self-administration and is associated with changes in dopamine (DA) function before drug exposure. Using positron emission tomography, we demonstrated that D2/3 receptor availability is significantly reduced in the nucleus accumbens of impulsive rats that were never exposed to cocaine and that such effects are independent of DA release. These data demonstrate that trait impulsivity predicts cocaine reinforcement and that D2 receptor dysfunction in abstinent cocaine addicts may, in part, be determined by premorbid influences.  相似文献