Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 18

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
A body of evidence accumulated over the past decade suggests that epigenetic mechanisms play an essential role in maintaining important cellular functions. Changes in epigenetic patterns (mainly DNA hyper- and hypomethylation and, more recently, histone modifications) may contribute to the development of cancer. Aberrant epigenetic events expand thorough tumor progression from the earliest to latest stages, therefore they can serve as convenient markers for detection and prognosis of cancer. The potential reversibility of epigenetic states in the tumor cell is an attractive target for cancer therapy. Much of our current knowledge on epigenetic alternations in cancer comes from studies on gastrointestinal malignancies, mainly on colorectal cancer, which currently serves as a model for epigenetic tumorigenesis. This review summarizes the current knowledge of epigenetic changes in gastrointestinal cancers and how this relates directly to disease progression and prognosis.
The aim of this study was to characterize the profile of volatile compounds in bright beers of lager type, produced with a different share of rice used as a partial replacement of barley malt. The share of unmalted raw material in total clod amounted to: 0, 5, 15 and 25%. The original extract was 11,5 °Blg. The partial replacement of barley malt with rice contributed to obtain the products, whose profile of volatile compounds has changed compared to traditional beer. It has been found that the flavor of beer produced with rice is mainly a result of the presence of fifteen different volatile compounds and 3-methyl-1-butanol and ethyl ester of caproic acid were the predominant volatile compounds. The addition of rice during beer production has a significant impact on the increase in the content of 2-methyl-1-butanol and phenyloethyl acetate, as well as on the decrease in hexane and isoamyl acetate.
W pracy przedstawiono analizę profili związków lotnych szynek surowo dojrzewających przy zastosowaniu techniki SPME (mikroekstrakcja do fazy stałej) w połączeniu z GC-MS (chromatografia gazowa sprzężona ze spektrometrią mas) oraz technikami chemometrycznymi PCA (analiza składowych głównych) i CA (analiza skupień). Przebadano szynki pochodzące: z Hiszpanii – Serrano, z Włoch – Parma, Crudo, Mantovelle, z Polski – kumpiak podlaski i z Niemiec – Schinkenspeck. W przebadanych szynkach zidentyfikowano 61 związków lotnych, które zakwalifikowano do następujących grup: aldehydy (14), ketony (3), alkohole (7), estry (9), alkany (6), węglowodory aromatyczne (2), kwasy (4), związki heterocykliczne (1), terpeny (11), fenole (1), inne (3). Dominującymi grupami były aldehydy i alkohole. Stwierdzono obecność alifatycznych aldehydów nasyconych (2-metylobutanalu i 3-metylobutanalu), które stanowią dobry wskaźnik procesu oksydacji, zachodzącego w szynkach surowo dojrzewających oraz produktów utleniania kwasów tłuszczowych (heksanal, oktanal). Obróbka chemometryczna umożliwiła zróżnicowanie badanego materiału oraz rozróżnienie szynek między innymi ze względu na technologię produkcji. Po zastosowaniu analizy składowych głównych oraz analizy skupień wyodrębniono 4 grupy szynek: włoskie i hiszpańskie, szynkę polską i szynkę niemiecką. Połączenie analizy instrumentalnej z metodami chemometrycznymi może być użyteczne do określania pochodzenia produktu i jego autentyczności.
The aim of this study was to investigate changes of volatile compounds in Rokpol blue cheeseduring storage under different temperature conditions (4℃, 25℃, 35℃). Headspace solid-phasemicroextraction (HS-SPME) was used to isolate volatile compounds from the matrix and GC/MS wasused for compounds separation and identification. Received aroma profiles were showed in the analyzed cheese and statistical analysis were done based on the identified groups of compounds. Results were interpreted on the basis of principal component analysis and cluster analysis. The dominant group of compounds represented ketones. The largest decrease in quality in the profile of volatile compounds was observed during storage at 25℃. Profile of volatile compounds remainssimilar during the week in 4℃ and two days at 25℃
We report on a 13-month-old girl showing dysmorphic features and a delay in psychomotor development. She was diagnosed with a balanced de novo translocation 46,X,t(X; 13)(p 11,2; p 13) and non-random inactivation of the X chromosome. FISH analysis, employing the X chromosome centromere and XIST-region-specific probes, showed that the XIST locus was not involved in the translocation. Selective inactivation of paternal X, which was involved in translocation, was revealed by the HUMARA assay. The pattern of methylation of 5 genes located within Xp, which are normally silenced on an inactive X chromosome, corresponded to an active (unmethylated) X chromosome. These results revealed that in our proband the X chromosome involved in translocation (Xt) was preferentially inactivated. However, genes located on the translocated Xp did not include XIST. This resulted in functional Xp disomy, which most probably accounts for the abnormal phenotype in our patient.
The association between polymorphism in both DNA repair and xenobiotic metabolism genes and can­cer risk has been reported by many authors. Recent studies have revealed the genetic heterogeneity of various populations. Therefore, the aim of our study was to evaluate the frequency of selected polymor­phisms/mutations in 17 minor susceptibility genes and to analyze the pattern of their distribution in a group of 146 healthy, young Polish individuals.The results of our study show that the distribution of studied polymor­phisms displayed a distinct pattern.
CHEK2 gen encodes cell cycle checkpoint kinase 2 that participates in the DNA repair pathway, cell cycle regulation and apoptosis. Mutations in CHEK2 gene may result in kinase inactivation or reduce both catalytic activity and capability of binding other proteins. Some studies indicate that alterations in CHEK2 gene confers increase the risk of breast cancer and some other malignancies, while the results of other studies are inconclusive. Thus the significance of CHEK2 mutations in aetiology of breast cancer is still debatable. The aim of our study was to evaluate the relationship between the breast/ovarian cancer and CHEK2 variants by: i) the analysis of the frequency of selected CHEK2 variants in breast and ovarian cancer patients compared to the controls; ii) evaluation of relationships between the certain CHEK2 variants and clinico-histopathological and pedigree data. The study was performed on 284 breast cancer patients, 113 ovarian cancer patients and 287 healthy women. We revealed the presence of 430T > C, del5395 and IVS2 + 1G > A variants but not 1100delC in individuals from both study and control groups. We did not observe significant differences between cancer patients and controls neither in regard to the frequency nor to the type of CHEK2 variants. We discussed the potential application of CHEK2 variants in the evaluation of breast and ovarian cancer predisposition.
The aim of the research was to analyze the volatile compounds in beers manufactured with the use of maize grits, as unmalted raw material. Three batches of beer were produced on a laboratory scale. The participation of maize grits in each batch amounted to 0, 15 and 25% respectively. The SPME technique was used to extract volatile compounds (Solid Phase Microextraction), whereas the gas chromatography coupled with mass spectrometry was applied to analyze separated compounds. In the examined beers, there were 15 volatile compounds identified and they were divided into 5 groups: esters (7), alkohols (5), hydrocarbons (1), alkanes (1), sulfides (1).
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 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.