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761.
The aim of this study was to compare Toxoplasma gondii infection in three canid species: red fox Vulpes vulpes, arctic fox Vulpes lagopus and raccoon dog Nyctereutesprocyonoides kept at the same farm. Anal swabs were taken from 24 adult and 10 juvenile red foxes, 12 adult arctic foxes, three adult and seven juvenile raccoon dogs. Additionally, muscle samples were taken from 10 juvenile red foxes. PCR was used to detect T. gondii DNA. T. gondii infection was not detected in any of the arctic foxes; 60% ofraccoon dogs were infected; the prevalence of the parasite in material from red fox swabs was intermediate between the prevalence observed in arctic foxes and raccoon dogs. It is possible that susceptibility and immune response to the parasite differ between the three investigated canid species. T. gondii DNA was detected in muscle tissue of five young foxes. The results of this study suggest that T. gondii infection is not rare in farmed canids. 相似文献
762.
A Kasperowicz K Stan-Glasek W Guczynska P Pristas P Javorsky A Vandzurova T Michalowski 《World journal of microbiology & biotechnology》2012,28(3):1271-1279
The subject of this study was the fructan and sucrose degrading enzymes of bacterium Pseudobutyrivibrio ruminis strain 3. It was stated that cell extract from bacteria growing on inulin contained β-fructofuranosidase (EC 3.2.1.80 and/or
EC 3.2.1.26) and sucrose phosphorylase (EC 2.4.1.7), while the bacteria maintained on sucrose showed only phosphorylase. Partially
purified β-fructofuranosidase digested inulooligosaccharides and sucrose to fructose or fructose and glucose, respectively,
but was unable to degrade the long chain polymers of commercial inulin and Timothy grass fructan. Digestion rate of inulooligosaccharides
fit Michaelis–Menten kinetics with Vmax 5.64 μM/mg/min and Km 1.274%, respectively, while that of sucrose was linear. Partially purified sucrose phosphorylase digested only sucrose. The
digestion products were fructose, glucose-1P and free glucose. The reaction was in agreement with Michaelis–Menten kinetics.
The Vmax were 0.599 and 0.584 μM/mg/min, while Km were 0.190 and 0.202% for fructose release and glucose-1P formation, respectively, when bacteria grew on inulin. The Vmax were, however, 1.37 and 1.023 μM/mg/min, while Km were 0.264 and 0.156%, if bacteria were grown on sucrose. The free glucose was hardly detectable for the enzyme originated
from inulin grown bacteria, but glucose levels ranged from 0.05 to 0.25 μM/mg/min, when cell extract from bacteria grown on
sucrose was used. Release of free glucose was observed when no inorganic phosphate was present in reaction mixture. 相似文献
763.
Pietras T Szemraj J Panek M Witusik A Banasiak M Antczak A Górski P 《Molecular biology reports》2012,39(3):2163-2167
Cyclooxygenase two (COX-2) is an important enzyme metabolizing arachidonic acid. In contrast to constitutive cyclooxygenase
one (COX-1), COX-2 is induced by proinflammatory factors. Polymorphism −765G/C in COX-2-encoding gene promoter is associated
with development of Alzheimer’s disease, depression, carcinoma of the pancreas in smokers, breast cancer and rheumatoid arthritis.
It is interesting whether the −765G/C polymorphism in COX-2-encoding gene promoter can be associated with COPD, a disease
which is inflammatory in character. It is highly probable as the breast and pancreas cancers, whose associations with the
analyzed polymorphism have been studied, are smoking-dependent tumors. Additionally, tobacco smoke has been demonstrated to
induce COX-2 in the lungs. The study group consisted of 122 COPD patients (48 females, 74 males). The control group consisted
of 149 healthy nonsmoking subjects (83 females, 66 males). Polymerase chain reaction/restriction fragment length polymorphism
was used for genotyping. A statistically significant difference in genotype distribution was observed as a result of the comparison
between healthy subjects and patients with COPD. The distribution of alleles in both groups conformed with Hardy–Weinberg
equilibrium. In the group of COPD patients, GG allele was found in 79 subjects, GC in 36, and CC in 7 subjects (F = 0.094,
P = 0.296927); in the control group, 73 subjects had GG allele, 68—GC and 8—CC (F = 0.12728, P = 0.120265). The allele frequency revealed differences between those groups, attaining the level of statistical significance
(χ2 = 29.043, df = 2, P = 0.0000. The carriers of −765G allele are at 1.53-fold higher risk of developing COPD. The presence of GG genotype does
not increase significantly the risk of the disease. It is also noteworthy that the carriers of CC or GC genotypes are at significantly
lower risk of developing COPD than the group of subjects with GG genotype. 相似文献
764.
Vijendravarma RK Narasimha S Kawecki TJ 《Proceedings. Biological sciences / The Royal Society》2012,279(1742):3540-3546
Chronic exposure to food of low quality may exert conflicting selection pressures on foraging behaviour. On the one hand, more active search behaviour may allow the animal to find patches with slightly better, or more, food; on the other hand, such active foraging is energetically costly, and thus may be opposed by selection for energetic efficiency. Here, we test these alternative hypotheses in Drosophila larvae. We show that populations which experimentally evolved improved tolerance to larval chronic malnutrition have shorter foraging path length than unselected control populations. A behavioural polymorphism in foraging path length (the rover-sitter polymorphism) exists in nature and is attributed to the foraging locus (for). We show that a sitter strain (for(s2)) survives better on the poor food than the rover strain (for(R)), confirming that the sitter foraging strategy is advantageous under malnutrition. Larvae of the selected and control populations did not differ in global for expression. However, a quantitative complementation test suggests that the for locus may have contributed to the adaptation to poor food in one of the selected populations, either through a change in for allele frequencies, or by interacting epistatically with alleles at other loci. Irrespective of its genetic basis, our results provide two independent lines of evidence that sitter-like foraging behaviour is favoured under chronic larval malnutrition. 相似文献
765.
Weijun Xuan Liyi Huang Yuguang Wang Xiaoqing Hu Grzegorz Szewczyk Ying‐Ying Huang Ahmed El‐Hussein Jerry C. Bommer Mark L. Nelson Tadeusz Sarna Michael R. Hamblin 《Journal of biophotonics》2019,12(8)
Antimicrobial photodynamic inactivation (aPDI) employs the combination of nontoxic photosensitizing dyes and visible light to kill pathogenic microorganisms regardless of drug‐resistance, and can be used to treat localized infections. A meso‐substituted tetra‐methylpyridinium porphyrin with one methyl group replaced by a C12 alkyl chain (FS111) and its Pd‐derivative (FS111‐Pd) were synthesized and tested as broad‐spectrum antimicrobial photosensitizers when excited by blue light (5 or 10 J/cm2). Both compounds showed unprecedented activity, with the superior FS111‐Pd giving 3 logs of killing at 1 nM, and eradication at 10 nM for Gram‐positive methicillin‐resistant Staphylococcus aureus. For the Gram‐negative Escherichia coli, both compounds produced eradication at 100 nM, while against the fungal yeast Candida albicans, both compounds produced eradication at 500 nM. Both compounds could be categorized as generators of singlet oxygen (ΦΔ = 0.62 for FS111 and 0.71 for FS111‐Pd). An in vivo study was carried out using a mouse model of localized infection in a partial thickness skin abrasion caused by bioluminescent Gram‐negative uropathogenic E. coli. Both compounds were effective in reducing bioluminescent signal in a dose‐dependent manner when excited by blue light (405 nm), but aPDI with FS111‐Pd was somewhat superior both during light and in preventing recurrence during the 6 days following PDT. 相似文献
766.
Tadeusz Majewski Hui Yao Jolanta Bondaruk Woonbok Chung Sangkyou Lee June Goo Lee Shizhen Zhang David Cogdell Guoliang Yang Woonyoung Choi Colin Dinney H. Barton Grossman Christopher Logothetis Steven E. Scherer Charles C. Guo Li Zhang Peng Wei John N. Weinstein Bogdan Czerniak 《Cell reports》2019,26(8):2241-2256.e4
767.
A Rapid and Efficient Method for Cloning Genes of Type II Restriction-Modification Systems by Use of a Killer Plasmid
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We present a method for cloning restriction-modification (R-M) systems that is based on the use of a lethal plasmid (pKILLER). The plasmid carries a functional gene for a restriction endonuclease having the same DNA specificity as the R-M system of interest. The first step is the standard preparation of a representative, plasmid-borne genomic library. Then this library is transformed with the killer plasmid. The only surviving bacteria are those which carry the gene specifying a protective DNA methyltransferase. Conceptually, this in vivo selection approach resembles earlier methods in which a plasmid library was selected in vitro by digestion with a suitable restriction endonuclease, but it is much more efficient than those methods. The new method was successfully used to clone two R-M systems, BstZ1II from Bacillus stearothermophilus 14P and Csp231I from Citrobacter sp. strain RFL231, both isospecific to the prototype HindIII R-M system. 相似文献
768.
Ciepichal E Wojcik J Bienkowski T Kania M Swist M Danikiewicz W Marczewski A Hertel J Matysiak Z Swiezewska E Chojnacki T 《Chemistry and physics of lipids》2007,147(2):103-112
A novel type of polyprenols, alloprenols, with an α-trans-isoprenoid unit was found in the leaves of Allophylus caudatus (Sapindaceae) besides typical α-cis-polyprenols. The polyprenol family (Prenol-11-13, Prenol-12 dominating) was accompanied by traces of dolichols of the same chain-length. Prenol α-cis- and α-trans-isomers were chromatographically separated and their structure was analyzed by HPLC/ESI-MS, HR-ESI-MS and 1H and 13C NMR spectroscopy. Model compounds, semi-synthetic α-isomers of all-trans-Pren-9 and mainly-cis-Pren-11, were obtained using an oxidation-reduction procedure. Comparison of their NMR spectra confirmed the structure of the newly identified polyprenols. The observed pattern of NMR signal shifts may be applied for elucidation of isoprenoid structure. 相似文献
769.
Lis GJ Litwin JA Furgal-Borzych A Zarzecka J Cichocki T 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2007,45(3):229-232
RAM11 is a mouse monoclonal anti-rabbit macrophage antibody recognizing connective tissue and vascular (atheromatous tissue) macrophages. This study demonstrates a cross-reaction of RAM11 with an unknown antigen in rabbit normal epithelial cells. Formalin-fixed, paraffin sections of the New Zealand White rabbit normal skin, oral mucosa, esophagus, small intestine and lung were immunostained with RAM11 antibody followed by goat anti-mouse Cy-3-conjugated antiglobulin. RAM11-positive immunofluorescence was observed in basal layer cells of stratified squamous epithelia (skin, oral mucosa, esophagus). No RAM11 immunostaining was found in any cells of simple (intestinal, bronchial) epithelia. These findings show that basal cells of stratified squamous keratinized and non-keratinized epithelia of the rabbit express an antigenic epitope which is common with that of macrophage antigen recognized by RAM11 monoclonal antibody. 相似文献
770.
Zadlo A Rozanowska MB Burke JM Sarna TJ 《Pigment cell research / sponsored by the European Society for Pigment Cell Research and the International Pigment Cell Society》2007,20(1):52-60
Melanin in the human retinal pigment epithelium (RPE) is believed to play an important photoprotective role. However, unlike in skin, melanosomes in the RPE are rather long-lived organelles, which increases their risk of modifications resulting from significant fluxes of light and high oxygen tension. In this work, we subjected purified bovine RPE melanosomes to prolonged aerobic exposure with intense visible and near ultraviolet radiation and studied the effects of irradiation on the melanosome's capacity to inhibit peroxidation of lipids induced by iron/ascorbate. We found that control, untreated melanosomes show a concentration-dependent inhibition of the accumulation of lipid hydroperoxides and the accompanying consumption of oxygen, but photolysed melanosomes lose their antioxidant efficiency and even became prooxidant. The prooxidant action of partially photobleached melanosomes was observed for pigment granules with a melanin content reduced by about 50% compared with untreated melanosomes, as determined by electron spin resonance spectroscopy. We have previously shown that a similar loss in the content of the RPE melanin occurs during human lifetime, which may suggest that the normal antioxidant properties of human RPE melanin become compromised with aging. 相似文献