Comparison of temperature shock timing to induced artificial mitotic gynogenesis and androgenesis in common tench     

Joanna Nowosad  Dariusz Kucharczyk  Tomasz Liszewski  Katarzyna Targońska  Roman Kujawa 《Aquaculture International》2015,23(1):45-53

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Changes in European eel ovary development and body and ovary chemistry during stimulated maturation under controlled conditions: preliminary data     

Joanna Nowosad  Dariusz Kucharczyk  Joanna Łuczyńska  Katarzyna Targońska  Tomasz Kajetan Czarkowski  Maria Biłas  Sławomir Krejszeff  László Horváth  Tamás Müller 《Aquaculture International》2015,23(1):13-27

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Characterization of a novel type of MLSB resistance plasmid from Staphylococcus saprophyticus carrying a constitutively expressed erm(C) gene     

Hauschild T  Lüthje P  Schwarz S 《Veterinary microbiology》2006,115(1-3):258-263

An erm(C)-carrying plasmid of unusual size and restriction map, designated pSES22, was identified in a Staphylococcus saprophyticus strain and sequenced completely. Constitutive expression of the erm(C) gene from pSES22 is based on a novel 22-bp tandem duplication in the erm(C) translational attenuator. Comparative analysis of the deduced Erm(C) amino acid sequence revealed that Erm(C) from pSES22 - together with an Erm(C) methylase from S. hyicus - represented a separate branch in the homology tree of Erm(C) methylases. Structural comparisons showed that plasmid pSES22 differed distinctly from all other completely sequenced erm(C)-carrying resistance plasmids. However, pSES22 was similar to several members of a diverse group of small plasmids, all of which carried closely related plasmid backbones consisting of the genes repU and pre/mob, but differed in their resistance genes.  相似文献   

Response of spruce stands in national parks of southern Poland to air pollution in 1998–2005     

Tomasz Staszewski  Piotr Kubiesa  Włodzimierz Łukasik 《European Journal of Forest Research》2012,131(4):1163-1173

The purpose of this study was to describe changes in the deposition of air pollutants and the response of spruce trees in the period of 1998–2005. The investigation was carried out in twelve sites, mainly national parks. Air pollution level, that is, SO₂, NO₂, and O₃ concentrations in the air, as well as throughfall and soil solution chemical composition was analysed. The reaction of trees was described based on a stand health parameter, that is, defoliation. A decrease in the concentration of SO₂ and NO₂ in the investigated period was observed. In most of the analysed sites, ozone concentrations in the growing season exceeded the level regarded as harmful to plants. Annual loads of nitrogen and sulphur reaching the forest soil exceeded 10 kg/ha. The data collected for the analysed period confirmed that the health status of forests at the investigated sites did not show a general tendency towards improvement. Also, no dependency between the air pollution level and defoliation rate was found.  相似文献   

Influence of Dexamethasone on Some Cellular Aspects of the Immune System in Cats     

Hoffmann-Jagielska M  Winnicka A  Jagielski D  Lechowski R 《Veterinary research communications》2003,27(8):643-652

In view of the frequent use of glucocorticoids in the treatment of cats, we studied the effect of dexamethasone on their immunological system. The phagocytic activity and oxidative burst of neutrophils and monocytes were evaluated by cytometric analysis using commercial kits and the subpopulations of lymphocytes were assessed. Neutrophilia and monocytosis reduced phagocytic activity, as shown from the number of phagocytized bacteria, and variations in the intensity of the oxidative burst in activated neutrophils and monocytes were observed. Dexamethasone also caused an increase in the number of B lymphocytes.  相似文献   

Cytometric evaluation of peripheral blood lymphocytes in dogs with lymphoma during chemotherapy     

Winnicka A  Jagielski D  Hoffmann-Jagielska M  Lechowski R 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2002,49(6):303-306

Twenty dogs with clinically diagnosed multicentric lymphoma were evaluated for percentages of peripheral blood lymphocyte subpopulations. Cytometric analysis was performed before and during chemotherapy. The results were compared to those obtained from a control group of healthy dogs. The percentages of CD5+, CD4+ and CD8+ cells were markedly decreased and CD21-like+ cells markedly increased in dogs with lymphoma in comparison with the control group. During the course of chemotherapy these values returned to ranges observed in healthy animals.  相似文献   

Dependence of the lactation duration and efficiency on the season of lambing in relation to the prolactin and melatonin secretion in ewes     

Edyta Molik  Tomasz Misztal  Katarzyna Romanowicz  Edward Wierzcho 《Livestock Science》2007,107(2-3):220-226

Changes in day length and the related secretion of melatonin and prolactin are of particular significance in sheep, as they determine reproductive processes, the last stage of which is lactation. The aim of the present study was to examine the dependence of the lactation duration and efficiency on the season of lambing (January—Group I/June—Group II) in relation to the hormonal status of milking ewes (Polish Longwool). The possibility of artificial extension of the milking period in late-lambing ewes by application of prolonged day length, 16 h of light–8 h of darkness (16L:8D), was introduced additionally (Group III). Measurements of plasma levels of prolactin and melatonin were used as parameters of season-dependent hormonal regulation of milk production in this seasonally breeding species. Although during the first 28 days of lactation sheep of all groups produced similar amounts of milk (based on the weight gains of the lambs), our results clearly showed that during the period of machine milking (from weaning at 56 day to the dry period) the level of milk production in Group I was almost twice that noted in Group II. Thus, the highest milk yield was obtained from sheep during the period when the days became longer, i.e. from March to May, which was accompanied by an increase in prolactin secretion. In both groups, melatonin secretion was found to increase while milk performance parameters and prolactin secretion decreased during the shortening photoperiod. The sustained decreases in milk production and prolactin secretion were also observed during the autumn months in sheep from Group III, despite the low level of melatonin. The present study showed that time of lambing and related photoperiod length could significantly affect the milk production of sheep that have a clear season of sexual activity. Maintenance of June-lambing sheep under the 16L:8D regime failed to extend the high prolactin level and lactation considerably into the autumn months. The spontaneous decrease in prolactin secretion observed under the long artificial photoperiod indicated for a development of refractoriness, which could also limit the lactation period.  相似文献   

Effects of prostaglandin F(2alpha) and nitric oxide on the secretory function of bovine luteal cells   总被引：1，自引：0，他引：1  

Korzekwa A  Jaroszewski JJ  Bogacki M  Deptula KM  Maslanka TS  Acosta TJ  Okuda K  Skarzynski DJ 《The Journal of reproduction and development》2004,50(4):411-417

The objective of the present study was to investigate the influence of prostaglandin F(2alpha) (PGF (2alpha)) and nitric oxide (NO) on production of steroids and PGs by culturing bovine luteal cells obtained from ovaries on days 8-12 of the estrous cycle with a nitric oxide (NO) donor (Spermine NONOate), and a NO synthase inhibitor (N(G)-nitro-L-arginine methyl ester dihydrochloride: L-NAME). When the cells were exposed for 24 h to PGF(2alpha) (10(-7)-10(-5) M), production of progesterone (P(4)) increased significantly at all doses used (P<0.05). Moreover, PGF(2alpha) stimulated PGF(2alpha) production (P<0.01), depressed testosterone (T) production (P<0.05), but did not affect synthesis of prostaglandin E(2) (PGE(2)). Spermine NONOate decreased P(4) production to 66%, 47% and 34% of the control concentration after treatment with 10(-5) M, 10(-4) M and 10(-3) M, respectively, but did not affect T production, and increased PGF(2alpha) synthesis (P<0.05) and PGE(2) (P<0.01) at all doses used. L-NAME increased production of P(4) (P<0.01) but did not affect (P>0.05) secretion of T, PGF(2alpha) and PGE(2). Estradiol-17beta (E(2)) was detectable on the level of sensitivity of assay and was not significantly altered by any treatments. The overall results suggest that PGF(2alpha) and NO produced locally in bovine CL play roles in the regulation of the secretory function of the bovine CL as auto/paracrine factors.  相似文献   

Acclimation of leaves to contrasting irradiance in juvenile trees differing in shade tolerance     

Wyka T  Robakowski P  Zytkowiak R 《Tree physiology》2007,27(9):1293-1306

Leaves developing in different irradiances undergo structural and functional acclimation, although the extent of trait plasticity is species specific. We tested the hypothesis that irradiance-induced plasticity of photosynthetic and anatomical traits is lower in highly shade-tolerant species than in moderately shade-tolerant species. Seedlings of two evergreen conifers, shade-tolerant Abies alba Mill. and moderately shade-tolerant Picea abies Karst., and two deciduous angiosperm species, highly shade-tolerant Fagus sylvatica L. and moderately shade-tolerant Acer pseudoplatanus L., were grown in deep shade (LL, 5% of full irradiance) or in full solar irradiance (HL) during 2003 and 2004. Steady state responses of quantum yield of PSII (Phi(PSII)), apparent electron transport rate (ETR), nonphotochemical quenching (NPQ) and photochemical quenching (qP) were generally modified by the light environment, with slower declines in Phi(PSII) and qP and greater maximal ETR and NPQ values in HL plants in at least one season; however, no link between quantitative measures of plasticity of these traits and shade tolerance was found. Plasticity of nine anatomical traits (including palisade cell length, which was reduced in LL) showed no relationship with shade tolerance, but was less in conifers than in deciduous trees, suggesting that leaf life span may be a significant correlate of plasticity. When LL-acclimated plants were exposed to HL conditions, the degree and duration of photoinhibition (measured as a decline in maximum quantum yield) was greatest in F. sylvatica, much lower in P. abies and A. alba, and lowest in A. pseudoplatanus. Thus, as with the other traits studied, vulnerability to photoinhibition showed no relationship with shade tolerance.  相似文献   

Rapid pneumococcal evolution in response to clinical interventions   总被引：1，自引：0，他引：1  

Croucher NJ  Harris SR  Fraser C  Quail MA  Burton J  van der Linden M  McGee L  von Gottberg A  Song JH  Ko KS  Pichon B  Baker S  Parry CM  Lambertsen LM  Shahinas D  Pillai DR  Mitchell TJ  Dougan G  Tomasz A  Klugman KP  Parkhill J  Hanage WP  Bentley SD 《Science (New York, N.Y.)》2011,331(6016):430-434

Epidemiological studies of the naturally transformable bacterial pathogen Streptococcus pneumoniae have previously been confounded by high rates of recombination. Sequencing 240 isolates of the PMEN1 (Spain(23F)-1) multidrug-resistant lineage enabled base substitutions to be distinguished from polymorphisms arising through horizontal sequence transfer. More than 700 recombinations were detected, with genes encoding major antigens frequently affected. Among these were 10 capsule-switching events, one of which accompanied a population shift as vaccine-escape serotype 19A isolates emerged in the USA after the introduction of the conjugate polysaccharide vaccine. The evolution of resistance to fluoroquinolones, rifampicin, and macrolides was observed to occur on multiple occasions. This study details how genomic plasticity within lineages of recombinogenic bacteria can permit adaptation to clinical interventions over remarkably short time scales.  相似文献