11 research outputs found

    8-oxo-7,8-dihydroguanine level – the DNA oxidative stress marker - recognized by fluorescence image analysis in sporadic uterine adenocarcinomas in women

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    Objectives: In the case of carcinogenesis in human endometrium no information exists on tissue concentration of 8-oxo-7,8-dihydroguanine, the DNA oxidative stress marker. This was the main reason to undertake the investigation of this DNA modification in human uterine estrogen-dependent tissue cancers. Material and Methods: In order to estimate the level of oxidative damage, 8-oxo-7,8-dihydroguanine was determined directly in cells of tissue microscope slides using OxyDNA Assay Kit, Fluorometric. Cells were investigated under confocal microscope. Images of individual cells were captured by computer-interfaced digital photography and analyzed for fluorescence intensities (continuous inverted 8-bit gray-scale = 0 [black]-255 [white]). Fluorescence scores were calculated for each of 13 normal endometrial samples and 31 uterine adenocarcinoma specimens. Finally, the level of the oxidative stress marker was also analyzed according to histological and clinical features of the neoplasms. Results: The obtained data revealed that: 8-oxo-7,8-dihydroguanine levels were higher in uterine adenocarcinomas than in normal endometrial samples (48,32 vs. 38,64;

    Rhizobium leguminosarum bv. trifolii rosR is required for interaction with clover, biofilm formation and adaptation to the environment

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    <p>Abstract</p> <p>Background</p> <p><it>Rhizobium leguminosarum </it>bv. <it>trifolii </it>is a symbiotic nitrogen-fixing bacterium that elicits nodules on roots of host plants <it>Trifolium </it>spp. Bacterial surface polysaccharides are crucial for establishment of a successful symbiosis with legumes that form indeterminate-type nodules, such as <it>Trifolium</it>, <it>Pisum</it>, <it>Vicia</it>, and <it>Medicago </it>spp. and aid the bacterium in withstanding osmotic and other environmental stresses. Recently, the <it>R. leguminosarum </it>bv. <it>trifolii </it>RosR regulatory protein which controls exopolysaccharide production has been identified and characterized.</p> <p>Results</p> <p>In this work, we extend our earlier studies to the characterization of <it>rosR </it>mutants which exhibit pleiotropic phenotypes. The mutants produce three times less exopolysaccharide than the wild type, and the low-molecular-weight fraction in that polymer is greatly reduced. Mutation in <it>rosR </it>also results in quantitative alterations in the polysaccharide constituent of lipopolysaccharide. The <it>rosR </it>mutants are more sensitive to surface-active detergents, antibiotics of the beta-lactam group and some osmolytes, indicating changes in the bacterial membranes. In addition, the <it>rosR </it>mutants exhibit significant decrease in motility and form a biofilm on plastic surfaces, which differs significantly in depth, architecture, and bacterial viability from that of the wild type. The most striking effect of <it>rosR </it>mutation is the considerably decreased attachment and colonization of root hairs, indicating that the mutation affects the first stage of the invasion process. Infection threads initiate at a drastically reduced rate and frequently abort before they reach the base of root hairs. Although these mutants form nodules on clover, they are unable to fix nitrogen and are outcompeted by the wild type in mixed inoculations, demonstrating that functional <it>rosR </it>is important for competitive nodulation.</p> <p>Conclusions</p> <p>This report demonstrates the significant role RosR regulatory protein plays in bacterial stress adaptation and in the symbiotic relationship between clover and <it>R. leguminosarum </it>bv. <it>trifolii </it>24.2.</p

    The use of morphometric and fractal parameters to assess the effects of 5-fluorouracil, interferon and dexamethasone treatment on colonic anastomosis healing: an experimental study in rats

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    Adjuvant chemotherapy and steroid therapy have been demonstrated to interfere with the wound healing process. The aim of this study was to evaluate the effects of 5-fluorouracil, interferon, and dexamethasone, on the healing of colon anastomosis by assessing morphometric and fractal parameters of the colonic wall. An experimental anastomosis of the ascending colon was performed in 60 male Wistar rats, which were then randomly assigned to four groups. On the second to sixth post-operative days, the rats were administered 5-fluorouracil, interferon-&#945;, dexamethasone, or 0.9% NaCl solution as a control. Macroscopic, histomorphometric and microbiological evaluation was performed in order to assess healing of the anastomosis. In three animals from the dexamethasone group, there was leakage of anastomosis; adhesion formation was highest in the interferon group, and significantly higher than in the control and 5-fluorouracil groups. Histomorphometric parameter alterations were most pronounced on the seventh and fourteenth post-operative days in all treatment groups, with submucosal thickness the most affected parameter. Connective tissue fractal dimension was significantly decreased in those animals treated with interferon and dexamethasone. All three pharmaceutical agents impaired healing of anastomosis, and promoted infection in the anastomosis and skin wound sites. As dexamethasone induced both morphometric and macroscopic alterations, it was considered the most detrimental in this study. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 1, pp. 80&#8211;89

    A comparison of cytokine production in 2-dimensional and 3-dimensional cultures of bone marrow stromal cells of multiple myeloma patients in response to RPMI8226 myeloma cells.

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    We examined cytokine production by bone marrow stromal cells (BMSCs) of patients with multiple myeloma (MM) in response to contact with myeloma RPMI8226 cells in standard 2-dimensional (2D) cultures and in 3-dimensional (3D) cultures on a gelatine sponge scaffold. It was detected that BMSCs in the 3D cultures produced more IL-11 and HGF and less IL-10 than in the 2D cultures. Moreover, RPMI8226 cells after contact with BMSCs in 3D cultures produced more sIL-6R than in the classic 2D cultures. We concluded that 3D cultures of BMSCs with myeloma cells offered a promising model for in vitro examination of interactions between myeloma cells and the bone marrow stroma and for examination of potent antimyeloma agents

    Relation Between Growth And Bone Collagen Content In Young Pigs; Effects Of Dietary Alpha-Ketoglutarate Supplementation

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    The aim of this study was to determine the effect of dietary supplementation with alpha-ketoglutarate (AKG) sodium salt on growth rate in relation to bone collagen formation during the first 70 d of postnatal life in piglets. The results show that dietary AKG supplementation increased body weight of the experimental piglets in comparison to the controls, especially between 21(st) and 56(th) d of life (P <= 0.01). Moreover, the area of collagen trabeculae slightly increased in experimental age sub-groups and reached the highest differences between 14(th) (P <= 0.01) and 70(th) d of piglets life (P <= 0.001). In contrast, the highest values for the number of collagen trabeculae were observed in piglets at 3(rd) d of age, regardless of treatment group. The positive effect of AKG supplementation on the number of collagen trabeculae was found between 3(rd) and 35(th) d of life, with statistical confirmation at days 14, 35, and 56 (P <= 0.01). The data-lines of the bone strain showed similar course during the whole experimental period, except 56(th) d of life, when the experimental piglets reached statistically significant, higher values in comparison to the controls (P <= 0.05). Similarly, the blood plasma osteocalcin reached the highest concentration in experimental sub-groups from 21(st) d of life in comparison to the controls, with statistical significance at the age of 56 (P <= 0.05). These data indicate that dietary AKG supplementation effectively stimulated collagen synthesis in young growing piglets, both before and after weaning

    Quercetin suppresses heat shock-induced nuclear translocation of Hsp72

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    The effect of quercetin and heat shock on the Hsp72 level and distribution in HeLa cells was studied by Western blotting, indirect immunofluorescence and immunogold electron microscopy. In control cells and after quercetin treatment, Hsp72 was located both in the cytoplasm and in the nucleus in comparable amounts. After hyperthermia, the level of nuclear Hsp72 raised dramatically. Expression of Hsp72 in cytoplasm was also higher but not to such extent as that observed in the nucleus. Preincubation of heated cells with quercetin inhibited strong Hsp72 expression observed after hyperthermia and changed the intracellular Hsp72 distribution. The cytoplasmic level of protein exceeded the nuclear one, especially around the nucleus, where the coat of Hsp72 was noticed. Observations indicating that quercetin was present around and in the nuclear envelope suggested an involvement of this drug in the inhibition of nuclear translocation. Our results indicate that pro-apoptotic activity of quercetin may be correlated not only with the inhibition of Hsp72 expression but also with suppression of its migration to the nucleus

    Dietary alpha-ketoglutarate reduces gastrectomy-evoked loss of calvaria and trabecular bone in female rats

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    Objective. Surgical removal of the stomach (gastrectomy, Gx) leads to osteopenia in animals and in humans. In the rat, Gx adversely affects calvaria and trabecular bone. alpha-Ketoglutarate (AKG) is a precursor of hydroxyproline - the most abundant amino acid in bone collagen. The purpose of this study was to investigate the effects of dietary AKG on Gx-induced osteopenia. Material and methods. Twenty female Sprague-Dawley rats were subjected to Gx and divided between two groups: Gx+AKG in the drinking water and Gx+Vehicle (i.e. drinking water without AKG). Another 20 rats were sham-operated and divided between two groups: Sham+AKG and Sham+Vehicle. The daily dose of AKG was 0.43 g per 100 g rat. All the rats were killed 8 weeks later and the calvariae, femora and tibiae were collected. The integrity of the calvariae was analysed planimetrically, following transillumination and photography. The bone mineral content (BMC) and bone mineral density (BMD) were measured in the right femorae and tibiae (bone densitometry), leaving the left femorae and tibiae to be analysed histomorphometrically (measurement of trabecular bone volume and trabecular fractal dimension). Results. Gx caused calvarial bone degradation, reduced trabecular bone (femur and tibia) and impaired trabecular architecture. In addition, Gx lowered the femoral/tibial BMC and BMD (mainly cortical bone). Dietary AKG counteracted the Gx-evoked impairment of calvaria and trabecular bone but failed to affect the BMC and the BMD in either sham-operated or Gx rats. Conclusions. Gx resulted in loss of calvarial, trabecular and cortical bone in the rat. AKG counteracted the effect of Gx on calvaria and trabecular bone but not on cortical bone

    The use of morphometric and fractal parameters to assess the effects of 5-fluorouracil, interferon and dexamethasone treatment on colonic anastomosis healing: an experimental study in rats

    No full text
    Adjuvant chemotherapy and steroid therapy have been demonstrated to interfere with the wound healing process. The aim of this study was to evaluate the effects of 5-fluorouracil, interferon, and dexamethasone, on the healing of colon anastomosis by assessing morphometric and fractal parameters of the colonic wall. An experimental anastomosis of the ascending colon was performed in 60 male Wistar rats, which were then randomly assigned to four groups. On the second to sixth post-operative days, the rats were administered 5-fluorouracil, interferon-&lt;i&gt;&amp;#945;&lt;/i&gt;, dexamethasone, or 0.9% NaCl solution as a control. Macroscopic, histomorphometric and microbiological evaluation was performed in order to assess healing of the anastomosis. In three animals from the dexamethasone group, there was leakage of anastomosis; adhesion formation was highest in the interferon group, and significantly higher than in the control and 5-fluorouracil groups. Histomorphometric parameter alterations were most pronounced on the seventh and fourteenth post-operative days in all treatment groups, with submucosal thickness the most affected parameter. Connective tissue fractal dimension was significantly decreased in those animals treated with interferon and dexamethasone. All three pharmaceutical agents impaired healing of anastomosis, and promoted infection in the anastomosis and skin wound sites. As dexamethasone induced both morphometric and macroscopic alterations, it was considered the most detrimental in this study. &lt;i&gt;(Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 1, pp. 80&amp;#8211;89
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