43 research outputs found

    The effect of vitamin C deficiency and chronic ultraviolet-B exposure on corneal ultrastructure: a preliminary investigation

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    Purpose: In the visually debilitating condition of climatic droplet keratopathy, corneal transparency is progressively lost. Although the precise cause of the disease and the mechanism by which it progresses are not known, a lifetime exposure to high solar radiation and a vitamin C–deficient diet may be involved in its development. This study examines the effect of dietary ascorbate levels and ultraviolet (UV)-B exposure on corneal stromal structure. Methods: Eight guinea pigs were divided into four treatment groups (A, B, C, and D). For 15 weeks, Groups A and C were fed an ascorbate-rich diet (2 mg/100 g bodyweight/day), while Groups B and D received an ascorbate-deficient diet (0.07 mg/100 g bodyweight/day). For the last 12 weeks of the study, Groups C and D also experienced chronic UVB exposure (0.12 J/cm2 for 40 min/day). Following euthanasia, the corneas were enucleated and their stromal ultrastructure examined using X-ray scattering and electron microscopy. Results: UVB exposure resulted in an increased corneal thickness (p<0.001), but this was not accompanied by a widespread expansion of the collagen fibrillar array, and in the case of ascorbate-deficient animals, stromal thickening was associated with the compaction of collagen fibrils (p<0.01). Neither UVB exposure nor ascorbic acid deficiency caused any change in the average diameter or D-periodicity of the stromal collagen fibrils. Conclusions: UVB-induced changes in the corneal ultrastructure were most pronounced in animals fed an ascorbic acid–deficient diet. This suggests that ascorbic acid may play a vital role in protecting the corneal stroma from the harmful effects of UVB

    Evaluating the Performance of Fabrics for Sportswear

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    This book describes the differences between woven and knitted structures, provides an understanding of fabric behavior and the characteristics of a functional garment, and outlines the importance of garment fit and consumer perception of ..

    The effect of vitamin C deficiency and chronic ultraviolet-B exposure on corneal ultrastructure: a preliminary investigation

    Get PDF
    Purpose: In the visually debilitating condition of climatic droplet keratopathy, corneal transparency is progressively lost. Although the precise cause of the disease and the mechanism by which it progresses are not known, a lifetime exposure to high solar radiation and a vitamin C–deficient diet may be involved in its development. This study examines the effect of dietary ascorbate levels and ultraviolet (UV)-B exposure on corneal stromal structure. Methods: Eight guinea pigs were divided into four treatment groups (A, B, C, and D). For 15 weeks, Groups A and C were fed an ascorbate-rich diet (2 mg/100 g bodyweight/day), while Groups B and D received an ascorbate-deficient diet (0.07 mg/100 g bodyweight/day). For the last 12 weeks of the study, Groups C and D also experienced chronic UVB exposure (0.12 J/cm2 for 40 min/day). Following euthanasia, the corneas were enucleated and their stromal ultrastructure examined using X-ray scattering and electron microscopy. Results: UVB exposure resulted in an increased corneal thickness (p<0.001), but this was not accompanied by a widespread expansion of the collagen fibrillar array, and in the case of ascorbate-deficient animals, stromal thickening was associated with the compaction of collagen fibrils (p<0.01). Neither UVB exposure nor ascorbic acid deficiency caused any change in the average diameter or D-periodicity of the stromal collagen fibrils. Conclusions: UVB-induced changes in the corneal ultrastructure were most pronounced in animals fed an ascorbic acid–deficient diet. This suggests that ascorbic acid may play a vital role in protecting the corneal stroma from the harmful effects of UVB

    Disturbed Expression of Splicing Factors in Renal Cancer Affects Alternative Splicing of Apoptosis Regulators, Oncogenes, and Tumor Suppressors

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    BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cancer. One of the processes disturbed in this cancer type is alternative splicing, although phenomena underlying these disturbances remain unknown. Alternative splicing consists of selective removal of introns and joining of residual exons of the primary transcript, to produce mRNA molecules of different sequence. Splicing aberrations may lead to tumoral transformation due to synthesis of impaired splice variants with oncogenic potential. In this paper we hypothesized that disturbed alternative splicing in ccRCC may result from improper expression of splicing factors, mediators of splicing reactions. METHODOLOGY/PRINCIPAL FINDINGS: Using real-time PCR and Western-blot analysis we analyzed expression of seven splicing factors belonging to SR proteins family (SF2/ASF, SC35, SRp20, SRp75, SRp40, SRp55 and 9G8), and one non-SR factor, hnRNP A1 (heterogeneous nuclear ribonucleoprotein A1) in 38 pairs of tumor-control ccRCC samples. Moreover, we analyzed splicing patterns of five genes involved in carcinogenesis and partially regulated by analyzed splicing factors: RON, CEACAM1, Rac1, Caspase-9, and GLI1. CONCLUSIONS/SIGNIFICANCE: We found that the mRNA expression of splicing factors was disturbed in tumors when compared to paired controls, similarly as levels of SF2/ASF and hnRNP A1 proteins. The correlation coefficients between expression levels of specific splicing factors were increased in tumor samples. Moreover, alternative splicing of five analyzed genes was also disturbed in ccRCC samples and splicing pattern of two of them, Caspase-9 and CEACAM1 correlated with expression of SF2/ASF in tumors. We conclude that disturbed expression of splicing factors in ccRCC may possibly lead to impaired alternative splicing of genes regulating tumor growth and this way contribute to the process of carcinogenesis

    Antibiotic resistance determinants in the interplay between food and gut microbiota

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    A complex and heterogeneous microflora performs sugar and lactic acid fermentations in food products. Depending on the fermentable food matrix (dairy, meat, vegetable etc.) as well as on the species composition of the microbiota, specific combinations of molecules are produced that confer unique flavor, texture, and taste to each product. Bacterial populations within such “fermented food microbiota” are often of environmental origin, they persist alive in foods ready for consumption, eventually reaching the gastro-intestinal tract where they can interact with the resident gut microbiota of the host. Although this interaction is mostly of transient nature, it can greatly contribute to human health, as several species within the food microbiota also display probiotic properties. Such an interplay between food and gut microbiota underlines the importance of the microbiological quality of fermented foods, as the crowded environment of the gut is also an ideal site for genetic exchanges among bacteria. Selection and spreading of antibiotic resistance genes in foodborne bacteria has gained increasing interest in the past decade, especially in light of the potential transferability of antibiotic resistance determinants to opportunistic pathogens, natural inhabitants of the human gut but capable of acquiring virulence in immunocompromised individuals. This review aims at describing major findings and future prospects in the field, especially after the use of antibiotics as growth promoters was totally banned in Europe, with special emphasis on the application of genomic technologies to improve quality and safety of fermented foods

    Cholesterol binding by lactic acid bacteria isolated from children

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    Celem niniejszej pracy było określenie zdolności Lactobacillus rhamnosus ATCC 9595, Lactobacillus casei ATCC 334 oraz szczepów bakterii fermentacji mlekowej wyizolowanych z kału zdrowych dzieci do wiązania cholesterolu w środowisku modelowego soku jelitowego i podłoża MRS Bulion. Do oznaczenia pozostałości cholesterolu w próbkach zastosowano diagnostyczny zestaw enzymatyczny Cholesterol RTU. Hodowle prowadzono w 24-dołkowych płytkach titracyjnych. Pomiary absorbancji przy oznaczaniu stop- nia wiązania cholesterolu oraz OD600 wykonano przy użyciu czytnika mikropłytek Spark 10M. Szczepy wykazujące największy stopień wiązania cholesterolu oceniono pod względem zdolności wzrostu oraz wiązania cholesterolu ze środowiska przy zwiększającym się obciążeniu cholesterolem [g/dm3 ]: 1,66, 2,85 i 3,75. L. rhamnosus i L. casei wykazywały zdolność do wiązania cholesterolu z podłoża MRS Bulion odpowiednio w 68,18 i 83,6 %, natomiast w modelowym soku jelitowym osiągały odpowiednio 60 i 50 %. Szczepy wyizolowane z kału dzieci charakteryzowały się dużą zmiennością w stopniu wiązania choleste- rolu ze środowiska, przy czym lepsze rezultaty osiągnięto w przypadku modelowego soku jelitowego (1,81 ÷ 77,99 %) niż podłoża MRS Bulion (0,49 ÷ 33,14 %). Przy zwiększającej się zawartości cholestero- lu w środowisku badane szczepy wykazywały zmniejszony przyrost biomasy, co korelowało ze zmniej- szonym stopniem wiązania tego związku. Największą redukcję cholesterolu z modelowego soku jelitowe- go uzyskano przy jego stężeniu – 1,66 g/dm3 . Stężenie cholesterolu 3,75 g/dm3 skutkowało zahamowaniem przyrostu biomasy, a tym samym najmniejszym ubytkiem tego związku ze środowiska

    Zmiany histopatologiczne w mięśniu piersiowym powierzchniowym bażantów ( Phasinus colchicus ; Phasinus c. Mongolicus)

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    The aim of investigation was the frequency of histopathological changes of the m. pectoralis superficialis of game and Mongolian pheasants of different ages. The samples for analyze from pectoral muscle were taken after bird slaughter immediately at 12, 16 and 20 weeks of age. Then with from the samples made the histological slides and stained with H + E coloring method to visualize of the muscle tissue structure. The muscle structure analysis was conducted per area 1.5 mm2 with the following histopathological changes: atrophy, shape changes, giant fibers, necrosis, hyaline degeneration, splitting, connective tissue hypertrophy and inflammatory. There was a small frequency of histopathological changes in both pheasant varieties. The most histopathological changes ware observed atrophy and changes of fiber shape. Other changes were sporadic. The connective tissue hypertrophy and inflammatory infiltration were not observed in any individuals. Mongolian pheasants found slightly higher frequency of histopathological changes, but these differences were not statistically significant. Considering the above facts, it can be stated that m. pectoralis superficialis both varieties of pheasants because of the small number of histopathological changes observed in their structure and their nutritional value are valuable raw materials for the high-quality food production
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