81 research outputs found

    Increased variability in ApcMin/+ intestinal tissue can be measured with microultrasound

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    Altered tissue structure is a feature of many disease states and is usually measured by microscopic methods, limiting analysis to small areas. Means to rapidly and quantitatively measure the structure and organisation of large tissue areas would represent a major advance not just for research but also in the clinic. Here, changes in tissue organisation that result from heterozygosity in Apc, a precancerous situation, are comprehensively measured using microultrasound and three-dimensional high-resolution microscopy. Despite its normal appearance in conventionally examined cross-sections, both approaches revealed a significant increase in the variability of tissue organisation in Apc heterozygous tissue. These changes preceded the formation of aberrant crypt foci or adenoma. Measuring these premalignant changes using microultrasound provides a potential means to detect microscopically abnormal regions in large tissue samples, independent of visual examination or biopsies. Not only does this provide a powerful tool for studying tissue structure in experimental settings, the ability to detect and monitor tissue changes by microultrasound could be developed into a powerful adjunct to screening endoscopy in the clinic

    Suppression of Phospholipase Dγs Confers Increased Aluminum Resistance in Arabidopsis thaliana

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    Aluminum (Al) toxicity is the major stress in acidic soil that comprises about 50% of the world's arable land. The complex molecular mechanisms of Al toxicity have yet to be fully determined. As a barrier to Al entrance, plant cell membranes play essential roles in plant interaction with Al, and lipid composition and membrane integrity change significantly under Al stress. Here, we show that phospholipase Dγs (PLDγs) are induced by Al stress and contribute to Al-induced membrane lipid alterations. RNAi suppression of PLDγ resulted in a decrease in both PLDγ1 and PLDγ2 expression and an increase in Al resistance. Genetic disruption of PLDγ1 also led to an increased tolerance to Al while knockout of PLDγ2 did not. Both RNAi-suppressed and pldγ1-1 mutants displayed better root growth than wild-type under Al stress conditions, and PLDγ1-deficient plants had less accumulation of callose, less oxidative damage, and less lipid peroxidation compared to wild-type plants. Most phospholipids and glycolipids were altered in response to Al treatment of wild-type plants, whereas fewer changes in lipids occurred in response to Al stress in PLDγ mutant lines. Our results suggest that PLDγs play a role in membrane lipid modulation under Al stress and that high activities of PLDγs negatively modulate plant tolerance to Al

    Badania hydrochemiczne systemu poziomów wodonośnych Drean–Annaba (północnowschodnia Algieria)

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    Water quality is subject to frequent changes in the Drean–Annaba alluvium aquifer. Water-rock interaction can not be the only process that produces the observed modification, but dryness that the country knew during the last two decades has highly contributed to the water quality changes. During this period, irregularities in the distribution of rainfalls, in time and space, have been observed. As a result, a periodicity in hydrochemical changes in water of wells and rivers is noticed. Statistical, the principals components analysis (PCA) tools and Tickel diagram have been used to show, through chemical presentation, these effects. The results show, indeed, seasonal changes of water quality for the period 1999–2000. From a cationic point of view, a competition between alkaline and alkaline earths is shown. On the other hand, from an anionic point of view, there is a transition from chlorides to sulphates and may be to bicarbonates. The present work was carried out in a relatively small area and this was useful to show the relationship that existed between dryness and water quality of both the aquifer system and surface water.W systemie aluwialnych poziomów wodonośnych Drean–Annaba jakość wody podlega częstym zmianom. Oddziaływania woda–podłoże skalne nie mogą być jedynymi procesami odpowiedzialnymi za obserwowane zmiany, natomiast susze, jakich kraj doświadczał w ciągu minionych dwóch dziesięcioleciach znacząco przyczyniły się do zmian jakości wody. W tym okresie obserwowano nieregularny rozkład opadów w czasie i przestrzeni. W konsekwencji zanotowano okresowość zmian hydrochemicznych właściwości wody w studniach i rzekach. Użyto statystycznych narzędzi, takich jak analiza składników głównych (PCA) i diagram Tickela do prezentacji wymienionych efektów. Uzyskane wyniki dowodzą sezonowych zmian jakości wody w okresie 1999–2000. W odniesieniu do kationów wykazano konkurencję pomiędzy pierwiastkami alkalicznymi i pierwiastkami ziem alkalicznych. W grupie anionów stwierdzono przejście od chlorków do siarczanów i prawdopodobnie do wodorowęglanów. Przedstawione badania prowadzono na stosunkowo małym obszarze, co okazało się korzystne dla wykazania zależności pomiędzy suszą a jakością wody zarówno w systemie poziomów wodonośnych, jak i w wodach powierzchniowych
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