Alteration of surfactant protein A expression in renal cell carcinoma

Surfactant protein-A (SP-A) belongs to a family of collagen-containing C-type lectins called collectins. SP-A is expressed by renal tubule epithelial cells. We investigated the distribution of SP-A in renal cell carcinomas (RCC) using immunohistochemical techniques and western blotting. We used 35 formalin fixed, paraffin embedded (FFPE) RCC tissue samples. We compared results with clinico-pathological parameters of RCC including age, sex, Fuhrman grade, tumor volume, tumor node metastasis (TNM) and clinical stage. SP-A was localized in the glomerulus and renal tubule epithelium in nontumor tissue and strong SP-A immunoreactivity was observed in tumor tissue. SP-A was expressed in the RCC tumor cells (64%) and nontumor cells (34%) in males and RCC tumor cells (90%) and nontumor cells (30%) in females. There was a significant correlation between SP-A immunoreactivity in tumor cells and gender, age, tumor diameter, Fuhrman grade and tumor diameter. Western blot analysis supported the immunohistochemical findings. We present evidence for involvement of SP-A in RCC and suggest that increased SP-A expression in RCC is associated with favorable prognosis.     

Palatability and feeding preferences of Uresiphita maorialis (Lepidoptera: Crambidae) for three Sophora species

In a three-hour bioassay, we tested the palatability and feeding preferences of Uresiphita maorialis (kōwhai moth) for Sophora tetraptera, Sophora microphylla and Sophora prostrata. Palatability tests showed no differences among the Sophora species. Feeding preferences, on the other hand, showed that S. tetraptera and S. microphylla leaves are preferred over S. prostrata leaves. Our results support our field observations in Wellington city parks and gardens showing that S. tetraptera and S. microphylla plants frequently have higher densities of larvae than S. prostrata.     

Effect of unilateral and bilateral resistance exercise on maximal voluntary strength,total volume of load lifted,and perceptual and metabolic responses

The present study investigated the effect of unilateral and bilateral resistance exercise (RE) on maximal voluntary strength, total volume of load lifted (TVLL), rating of perceived exertion (RPE) and blood lactate concentration of resistance-trained males. Twelve healthy men were assessed for the leg extension one-repetition maximum (1RM) strength using bilateral and unilateral contractions. Following this assessment, an RE session (3 sets of repetitions to failure) was conducted with bilateral and unilateral (both limbs) contractions using a load of 50% 1RM. The TVLL was calculated by the product of the number of repetitions and the load lifted per repetition. RPE and blood lactate were measured before, during and after each set. Session RPE was measured 30 minutes after RE sessions. There was a significant difference in the bilateral (120.0±11.9) and unilateral (135.0±20.2 kg) 1RM strength (p < 0.05). The TVLL was similar between both RE sessions. Although the repetitions decreased with each successive set, the total number of repetitions completed in the bilateral protocol (48) was superior to the unilateral (40) protocol (p < 0.05). In both bouts, RPE increased with each subsequent set whilst blood lactate increased after set 1 and thereafter remained stable (p < 0.05). The RPE and lactate responses were not significantly different between both sessions. In conclusion, a bilateral deficit in leg extension strength was confirmed, but the TVLL was similar between both RE sessions when exercising to voluntary fatigue. This outcome could be attributed to the number of repetitions completed in the unilateral RE bout. The equal TVLL would also explain the similar perceptual and metabolic responses across each RE session.     

三氧化二砷对食管癌细胞增殖和热休克蛋白70表达的影响

目的：研究三氧化二砷（As2O3）对食管癌细胞增殖和热休克蛋白70（HSP70）表达的影响。方法：通过相差显微镜、流式细胞术、免疫细胞化学染色和免疫印迹分析等方法观察As2O3对人食管癌细胞株EC1的作用效果和作用机制。结果：与对照组相比,经2μmol/L和5μmol/Las2O3作用的细胞出现明显的生长抑制,G2/M期细胞比例增加;2μmol/Las2O3作用48h后经Ecl细胞HSP70（heat shock protein70）及HSC70(heat shock cognate protein70)表达均增加。结论：As2O3诱导食管癌细胞G2/M期阻滞抑制细胞增殖和生长;HSP70的升高是细胞对As2O3作用后出现的应激反应,并与细胞周期阻滞相关。     

KatG,the Bifunctional Catalase of Xanthomonas citri subsp. citri,Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves

Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS) at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV) radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H₂O₂, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG), carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H₂O₂. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H₂O₂. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H₂O₂ toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H₂O₂. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H₂O₂ and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance.     

Defibrotide, by enhancing prostacyclin generation, prevents endothelin-1 induced contraction in human saphenous veins

Spirals of human saphenous veins (HSV), mounted in a 5 ml organ bath containing Krebs-Henseleit solution (37 degrees C), when kept in contact with defibrotide (100-200 ug/ml) for 15 min, enhance (2 and 3 fold) their own basal release of 6-keto-PGF 1 alpha (61 +/- 1.3 pg/mg w.t. n = 12). The phenomenon was long lasting upon repeated washing and sensitive to indomethacin (1 ug/ml). Endothelin-1 (ET-1, 20-40 ng) induced a sustained contraction of HSV and concomitantly released from the venous tissue a proportional amount of 6-keto-PGF 1 alpha. Indomethacin (1 ug/ml), by inhibiting cyclo-oxygenase enzyme, potentiated the contractile activity of ET-1 in HSV whereas exogenous PGE2 (20 ng/ml) considerably reduced the tension developed by the peptide on this venous tissue. Defibrotide (200 ug/ml), by releasing 6-keto-PGF 1 alpha, and other vasoactive prostaglandins, antagonized the contractile effect ET-1 (20 ng) in HSV. This data indicates that the eicosanoid metabolism is involved in the modulation of the potent vasoconstrictor effect of ET-1 in HSV and that PGI2-releaser, such as defibrotide, may have therapeutical value against immoderate changes of venous tone.     

Intragenic duplication and divergence in the spectrin superfamily of proteins

Many structural, signaling, and adhesion molecules contain tandemly repeated amino acid motifs. The alpha-actinin/spectrin/dystrophin superfamily of F-actin-crosslinking proteins contains an array of triple alpha-helical motifs (spectrin repeats). We present here the complete sequence of the novel beta-spectrin isoform beta(Heavy)- spectrin (beta H). The sequence of beta H supports the origin of alpha- and beta-spectrins from a common ancestor, and we present a novel model for the origin of the spectrins from a homodimeric actin-crosslinking precursor. The pattern of similarity between the spectrin repeat units indicates that they have evolved by a series of nested, nonuniform duplications. Furthermore, the spectrins and dystrophins clearly have common ancestry, yet the repeat unit is of a different length in each family. Together, these observations suggest a dynamic period of increase in repeat number accompanied by homogenization within each array by concerted evolution. However, today, there is greater similarity of homologous repeats between species than there is across repeats within species, suggesting that concerted evolution ceased some time before the arthropod/vertebrate split. We propose a two-phase model for the evolution of the spectrin repeat arrays in which an initial phase of concerted evolution is subsequently retarded as each new protein becomes constrained to a specific length and the repeats diverge at the DNA level. This evolutionary model has general applicability to the origins of the many other proteins that have tandemly repeated motifs.      

Defibrotide, by enhancing prostacyclin generation, prevents endothelin-1 induced contraction in human saphenous veins

Spirals of human saphenous veins (HSV), mounted in a 5 ml organ bath containing Krebs-Henseleit solution (37°C), when kept in contact with defibrotide (100–200 ug/ml) for 15 min, enhance (2 and 3 fold) their own basal release of 6-keto-PGF_1α (61 ± 1.3 pg/mg w.t. n = 12). The phenomenon was long lasting upon repeated washing and sensitive to indomethacin (1 ug/ml). Endothelin-1 (ET-1, 20–40 ng) induced a sustained contraction of HSV and concomitantly released from the venous tissue a proportional amount of 6-keto-PGF_1α.Indomethacin (1 ug/ml), by inhibiting cyclo-oxygenase enzyme, potentiated the contractile activity of ET-1 in HSV whereas exogenous PGE₂ (20 ng/ml) considerably reduced the tension developed by the peptide on this venous tissue.Defibrotide (200 ug/ml), by releasing 6-keto-PGF_1α, and other vasoactive prostaglandins, antagonized the contractile effect ET-1 (20 ng) in HSV. This data indicates that the eicosanoid metabolism is involved in the modulation of the potent vasoconstrictor effect of ET-1 in HSV and that PGI₂-releaser, such as defibrptide, may have therapeutical value against immoderate changes of venous tone.