Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 26

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  reverse transcription polymerase chain reaction
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Water samples were collected from irrigation ditches and drainage canals surrounding fields in southern Greater Poland. Initially, the samples were subjected to low and highspeed centrifugation and obtained pellets were used to perform biological assays. Viral identification involved biological, electron microscopic as well as molecular methods. The occurrence of Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV) was demonstrated in 12 of the 17 examined water sources. The molecular analysis results showed TMV and ToMV co-infections in the analysed water samples. To our knowledge, this is the first report of tobamoviruses being found in environmental water in Poland.
Aim of the study: In view of the frequent occurrence of immunosuppression in pigeons, which is a consequence of viral infections, studies with the use of a synthetic immunomodulator (methisoprinol) were undertaken to evaluate its impact on the course of an experimental infection with PPMV-1. The aim of the study was to determine the usefulness of methisoprinol for the treatment or prophylaxis of viral infections in pigeons. Materials and Methods: Three groups of 5-week-old pigeons, with 15 birds in each, were used in the experiment. Before the experiment, the birds were tested for the presence of antibodies specific to paramyxovirus, and their sensitivity to PPMV-1 infection was evaluated. The virus had been cultured earlier on SPF chicken embryos of 9-12 days. The pigeons from all three groups were infected intravenously with aparamyxovirus suspension (strain APMV-1/ pigeon/Poland/AR3/95 obtained from the Veterinary Institute in Puławy) at a concentration of LD50 10-7 in 0.1 ml at a dose of 0.1 ml/pigeon. The birds in the experimental groups (B1 and B2) were immunomodulated with methisoprinol administered at a dose of 200 mg/1 kg of body weight. The immunomodulator was administered by intramuscular injection for 3 successive days before (group B1) or three successive days after (group B2) the experimental infection. Pigeons in group K (used as a control) were given water by intramuscular injection for 3 days before and 3 days after infection. On days 4, 8, and 12 after infection, 5 birds from each group were euthanized, and sections of internal organs (lung, kidney, brain), as well as cloacal swabs, were collected to detect viral RNA by the RT-PCR method. Results and discussion: Symptoms were recorded from the first day after infection. Neurological symptoms occurred in birds from all groups: in 100% of pigeons from groups B1 and K, and in 80% of pigeons from group B2. Deaths of birds occurred from day 5 after infection in group B1. In the other groups, deaths were observed from day 6 after infection. The total mortality of the infected birds ranged from 70% (group B2) to 100% (groups B1 and K). The resolution of symptoms was observed from day 6 after infection in pigeons from group B2. During molecular examination, it was noted that the highest number of positive samples (presence of PPMV-1) on each day of the investigation was obtained from brain samples and cloacal swabs. The highest number of positive results in kidney samples was obtained from groups B1 and K on day 4 after infection. On the successive days of the investigation the percentage of positive samples increased to 100 in birds from all groups except group B2. Based On the basis of the results of the present study, it can be concluded that methisoprinol, used at a dose of 200 mg/kg of body weight after infection, has antiviral activity, manifested by a slower development of paramyxovirosis in pigeons infected intravenously with PPMV-1. Therefore, the administration of methisoprinol to naturally infected and diseased birds may be useful in the treatment of viral diseases.
 Quantitative real-time RT-PCR study was conducted to reveal the effects of normal (5 mmol/l) and high (30 mmol/l) glucose without or with oleate (0.3 mmol/l) on mRNA levels of peroxisome proliferator-activated receptor- (PPAR-)α, -γ1, -γ2, and peroxisome proliferator-activated receptor-γ coactivator- (PGC-)1α and -1β in commercial human hepatoma-derived HepG2 cells maintained under low-serum condition. Significant decrease in PPAR-γ1 and PGC-1α mRNA levels to about 50 % was observed during the first 4 h incubation period. During the next 4 h period, both PPAR-γ1 and PGC-1α mRNAs were partly but significantly restored in high glucose batches. In this period, the presence of the transcriptional inhibitor actinomycin D revealed a significant protective effect of excess glucose on mature PPAR-γ1 and PGC-1α mRNAs. Furthermore, PPAR-γ1 and -γ2 mRNAs were differentially superinduced 1.2-2.5 fold in cells upon the administration of the translational inhibitor cycloheximide. When the cells were co-treated with the combination of cycloheximide and actinomycin D, superinduction was completely suppressed, however. Altogether, the experiments revealed, first, an unexpected protective effect of abundant glucose on PPAR-γ1 and PGC-1α mRNAs in HepG2 cells. Second, we demonstrated cycloheximide-induced, transcription-dependent upregulation of mature PPAR-γ1 and -γ2 mRNAs in HepG2 cells associated with preferential expression of the PPAR-γ2 mRNA variant. The results draw attention to as yet unexplored mechanisms involved in the control of PPAR and PGC genes.
13
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Cloning and expression analysis of LeTIR1 in tomato

84%
The full-length cDNA of LeTIR1 gene was isolated from tomato with EST-based in silico cloning followed by RACE amplification. LeTIR1 contained an open reading frame (ORF) 1872 bp long, encoding 624 amino acid residues. The predicted protein LeTIR1 had one F-box motif and eleven leucine-rich repeats (LRRs), all of which are highly conserved in TIR1 proteins of other plant species. Phylogenetic analysis showed that the LeTIR1 protein shared high similarity with other known TIR1 proteins. Both sequence and phylogenetic analysis suggested that LeTIR1 is a TIR1 homologue and encodes an F-box protein in tomato. Semi-quantitative RT-PCR indicated that LeTIR1 was expressed constitutively in all organs tested, with higher expression in stem than root, leaf, flower and fruit. Its expression level was positively correlated with the auxin distribution in stem or axillary shoot, and was induced by spraying exogenous IAA.
The suitability of DAS-ELISA and RT-PCR methods for detection of 15 cucum¬ber mosaic virus (CMV) isolates found in Poland was compared. The effectiveness of DAS-ELISA depended on polyclonal antibodies (PAb) used in the assay. Antibodies Wic and DTL detected all tested isolates, whereas antibodies M could not detect iso¬late P26, antibodies ToRS did not react with isolate Porz, and isolate Simp2 was not detected by antibodies Cas. The RT-PCR technique allowed detection of all virus isolates. Three nucleic acid extraction methods: immunocapture (IC), silicacapture (SC) and isolation of the total RNA with the commercial kit (RN), proved to be effec-tive. These three nucleic acid extraction methods all allowed CMV amplification by RT-PCR. Three methods were used to identify and group the CMV isolates: 1) ELISA with group-specific monoclonal antibodies (MAbs), 2) phylogenetic analy¬sis of coat protein gene sequence and 3) restriction analysis of PCR-amplified RNA2 and RNA3 fragments digested with EcoRI, HpaII and MluI enzymes. MAbs used in ELISA allowed the preliminary classification of isolates to group I or II, but they failed to recognize one isolate (P26). CMV grouping based on CP sequence analysis enabled us to identify all of the tested isolates and discriminate between the two groups of CMV - IA and II. Classification based on RT-PCR-RFLP analysis corre¬lated with phylogenetic grouping based on sequencing.
Diversity of three isolates of Zucchini yellow mosaic virus (ZYMV) was analyzed by the biological and genetic characterization. Two isolates were collected from zucchini plants and one from cucumber. The symptoms induced on most hosts were different. In addition, analysis of the coat protein (CP) and nuclear inclusion protein b (Nib) of the ZYMV genome revealed high level of nucleotide variability among the isolates. Comparison of the DNA sequences of 22 isolates from different geographical regions worldwide revealed that the Polish isolates belong to different groups and they do not form a monophyletic cluster with European isolates.
Globalization resulted in increased international movement of both people and plant material or plant products, including seeds. It is estimated that up to one third of all plant viruses might be seed-borne in at least one of their hosts. In this way viruses may be comparatively easy spread to regions where they have not previously been reported. Dissemination of viruses by seeds might be minimized by using the molecular diagnostic tools. In this paper a problems connected with the detection of viruses in seeds are presented.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.