The ameliorative effects of vinpocetine on apoptosis and HSP-70 expression in testicular torsion in rats

Vinpocetine is a potent antioxidant and free radical scavenger. We investigated the effects of vinpocetine on torsion/detorsion (T/D) induced testicular damage, HSP-70 expression and germ cell apoptosis in rats. Sixty Wistar albino adult male rats were divided into five groups of 12. The groups comprised a control group, a sham treated group, a T/D group, a vinpocetine treated group, and a T/D plus vinpocetine treated group. The left testis of each rat was subjected to unilateral torsion followed by detorsion after 2 h. Vinpocetine was administered intraperitoneally immediately and for 10 days following detorsion. At the end of the study, the rats were sacrificed and their testes removed and processed. HSP-70 expression, apoptosis and histopathological damage scores were determined for each group. Testicular T/D caused significant increases in apoptosis and HSP-70 expression, and a significant decrease in Johnsen’s testicular biopsy scores and mean seminiferous tubule diameter. Vinpocetine ameliorated testicular histopathology and HSP-70 expression in the T/D + vinpocetine group. Consequently, vinpocetine may prevent testicular injury following testicular torsion owing to its antioxidant effects.     

Identification and characterization of protein interactions in the mammalian mRNA processing body using a novel two-hybrid assay

Components of the mRNA processing body (P-body) regulate critical steps in mRNA storage, transport, translation and degradation. At the core of the P-body is the decapping complex, which removes the 5′ cap from de-adenylated mRNAs and mediates an irreversible step in mRNA degradation. The assembly of P-bodies in Saccharomyces cerevisiae, Arabidopsis thaliana and Drosophila melanogaster has been previously described. Less is known about the assembly of mammalian P-bodies. To investigate the interactions that occur between components of mammalian P-bodies, we developed a fluorescence-based, two-hybrid assay system. The assay depends on the ability of one P-body component, fused to an exogenous nuclear localization sequence (NLS), to recruit other P-body components to the nucleus. The assay was used to investigate interactions between P-body components Ge-1, DCP2, DCP1, EDC3, RAP55, and RCK. The results of this study show that the modified two-hybrid assay can be used to identify protein interactions that occur in a macromolecular complex. The assay can also be used to efficiently detect protein interaction domains. The results provide important insights into mammalian P-body assembly and demonstrate similarities, and critical differences, between P-body assembly in mammalian cells compared with that of other species.     

The art of strain improvement of industrial lactic acid bacteria without the use of recombinant DNA technology

The food industry is constantly striving to develop new products to fulfil the ever changing demands of consumers and the strict requirements of regulatory agencies. For foods based on microbial fermentation, this pushes the boundaries of microbial performance and requires the constant development of new starter cultures with novel properties. Since the use of ingredients in the food industry is tightly regulated and under close scrutiny by consumers, the use of recombinant DNA technology to improve microbial performance is currently not an option. As a result, the focus for improving strains for microbial fermentation is on classical strain improvement methods. Here we review the use of these techniques to improve the functionality of lactic acid bacteria starter cultures for application in industrial-scale food production. Methods will be described for improving the bacteriophage resistance of specific strains, improving their texture forming ability, increasing their tolerance to stress and modulating both the amount and identity of acids produced during fermentation. In addition, approaches to eliminating undesirable properties will be described. Techniques include random mutagenesis, directed evolution and dominant selection schemes.     

Antioxidant effect of carnosine treatment on renal oxidative stress in streptozotocin-induced diabetic rats

Nitric oxide (NO) plays a significant role in the development of diabetic nephropathy. We investigated the effects of an antioxidant, carnosine, on streptozotocin (STZ)-induced renal injury in diabetic rats. We used four groups of eight rats: group 1, control; group 2, carnosine treated; group 3, untreated diabetic; group 4, carnosine treated diabetic. Kidneys were removed and processed, and sections were stained with periodic acid-Schiff (PAS) and subjected to eNOS immunohistochemistry. Examination by light microscopy revealed degenerated glomeruli, thickened basement membrane and glycogen accumulation in the tubules of diabetic kidneys. Carnosine treatment prevented the renal morphological damage caused by diabetes. Moreover, administration of carnosine decreased somewhat the oxidative damage of diabetic nephropathy. Appropriate doses of carnosine might be a useful therapeutic option to reduce oxidative stress and associated renal injury in diabetes mellitus.     

Transformation of barley scutellum protoplasts: regeneration of fertile transgenic plants

 A system for barley transformation via polyethyleneglycol-mediated DNA uptake into protoplasts isolated directly from scutella and the regeneration of transgenic plants is reported. Scutellum protoplasts (cv. Clipper, an Australian malting cultivar) were co-transformed with plasmids Act 1-DGUS, containing the marker uidA gene, and pCaIneo, which contains the selectable marker neomycin phosphotransferase gene. Protoplast-derived calluses were selected on medium containing the antibiotic G418 (25 and 15 mg.l^–1) and macroscopic antibiotic resistant colonies were recovered. Fertile plants were regenerated from a callus line and molecular analysis confirmed transgene integration. Received: 11 October 1999 / Revision received: 11 February 2000 / Accepted: 11 February 2000     

The Bactericidal Activity of Carbon Monoxide–Releasing Molecules against Helicobacter pylori

Helicobacter pylori is a pathogen that establishes long life infections responsible for chronic gastric ulcer diseases and a proved risk factor for gastric carcinoma. The therapeutic properties of carbon-monoxide releasing molecules (CORMs) led us to investigate their effect on H. pylori. We show that H. pylori 26695 is susceptible to two widely used CORMs, namely CORM-2 and CORM-3. Also, several H. pylori clinical isolates were killed by CORM-2, including those resistant to metronidazole. Moreover, sub-lethal doses of CORM-2 combined with metronidazole, amoxicillin and clarithromycin was found to potentiate the effect of the antibiotics. We further demonstrate that the mechanisms underpinning the antimicrobial effect of CORMs involve the inhibition of H. pylori respiration and urease activity. In vivo studies done in key cells of the innate immune system, such as macrophages, showed that CORM-2, either alone or when combined with metronidazole, strongly reduces the ability of H. pylori to infect animal cells. Hence, CORMs have the potential to kill antibiotic resistant strains of H. pylori.     

Symbiotic flagellate protists as cryptic drivers of adaptation and invasiveness of the subterranean termite Reticulitermes grassei Clément

Changes in flagellate protist communities of subterranean termite Reticulitermes grassei across different locations were evaluated following four predictions: (i) Rural endemic (Portugal mainland) termite populations will exhibit high diversity of symbionts; (ii) invasive urban populations (Horta city, Faial island, Azores), on the contrary, will exhibit lower diversity of symbionts, showing high similarity of symbiont assemblages through environmental filtering; (iii) recent historical colonization of isolated regions—as the case of islands—will imply a loss of symbiont diversity; and (iv) island isolation will trigger a change in colony breeding structure toward a less aggressive behavior. Symbiont flagellate protist communities were morphologically identified, and species richness and relative abundances, as well as biodiversity indices, were used to compare symbiotic communities in colonies from urban and rural environments and between island invasive and mainland endemic populations. To evaluate prediction on the impact of isolation (iv), aggression tests were performed among termites comprising island invasive and mainland endemic populations. A core group of flagellates and secondary facultative symbionts was identified. Termites from rural environments showed, in the majority of observed colonies, more diverse and abundant protist communities, probably confirming prediction (i). Corroborating prediction (ii), the two least diverse communities belong to termites captured inside urban areas. The Azorean invasive termite colonies had more diverse protist communities than expected and prediction (iii) which was not verified within this study. Termites from mainland populations showed a high level of aggressiveness between neighboring colonies, in contrast to the invasive colonies from Horta city, which were not aggressive to neighbors according to prediction (iv). The symbiotic flagellate community of R. grassei showed the ability to change in a way that might be consistent with adaptation to available conditions, possibly contributing to optimization of the colonization of new habitats and spreading of its distribution area, highlighting R. grassei potential as an invasive species.     

细胞周期与细胞凋亡

从海洋生物胚胎细胞到哺乳动物的细胞周期,主要是在其细胞周期基因产物周期素及Ｐ３４的调控下启动,运行和脱出周期的;某些原癌基因或抑癌基因的产物如ｐ５３,ｐＲＢ也直接调控着细胞周期。     

Land use change emission scenarios: anticipating a forest transition process in the Brazilian Amazon

Following an intense occupation process that was initiated in the 1960s, deforestation rates in the Brazilian Amazon have decreased significantly since 2004, stabilizing around 6000 km² yr^?1 in the last 5 years. A convergence of conditions contributed to this, including the creation of protected areas, the use of effective monitoring systems, and credit restriction mechanisms. Nevertheless, other threats remain, including the rapidly expanding global markets for agricultural commodities, large‐scale transportation and energy infrastructure projects, and weak institutions. We propose three updated qualitative and quantitative land‐use scenarios for the Brazilian Amazon, including a normative ‘Sustainability’ scenario in which we envision major socio‐economic, institutional, and environmental achievements in the region. We developed an innovative spatially explicit modelling approach capable of representing alternative pathways of the clear‐cut deforestation, secondary vegetation dynamics, and the old‐growth forest degradation. We use the computational models to estimate net deforestation‐driven carbon emissions for the different scenarios. The region would become a sink of carbon after 2020 in a scenario of residual deforestation (~1000 km² yr^?1) and a change in the current dynamics of the secondary vegetation – in a forest transition scenario. However, our results also show that the continuation of the current situation of relatively low deforestation rates and short life cycle of the secondary vegetation would maintain the region as a source of CO₂ – even if a large portion of the deforested area is covered by secondary vegetation. In relation to the old‐growth forest degradation process, we estimated average gross emission corresponding to 47% of the clear‐cut deforestation from 2007 to 2013 (using the DEGRAD system data), although the aggregate effects of the postdisturbance regeneration can partially offset these emissions. Both processes (secondary vegetation and forest degradation) need to be better understood as they potentially will play a decisive role in the future regional carbon balance.     

Granuloma Due to Oxidized Regenerated Cellulose in an Aged Rhesus Macaque (Macaca mulatta)

Bioabsorbable hemostatic agents such as oxidized regenerated cellulose are widely used to control intraoperative diffuse capillary bleeding. Compared with electrocautery or ligation, oxidized regenerated cellulose has the advantage of controlling bleeding without occluding the vessel lumen or causing thermal injuries to adjacent tissue. Although the manufacturer recommends removal of the material once hemostasis is achieved, oxidized regenerated cellulose is a bioabsorbable hemostatic agent and is often left in the surgical bed to prevent subsequent bleeding after surgical closure. However, noninvasive imaging techniques have revealed granulomatous foreign-body reactions that mimic infection or tumor recurrence. We present a case report of sterile peritonitis and granuloma formation secondary to the presence of oxidized regenerated cellulose after intestinal resection to excise a colonic adenocarcinoma in an aged rhesus macaque.Bioabsorbable hemostatic agents such as oxidized regenerated cellulose (for example, Surgicel) are widely used to control intraoperative diffuse capillary bleeding. Compared with electrocautery or ligation, oxidized regenerated cellulose has the advantage of controlling bleeding without occluding the vessel lumen or causing thermal injuries to adjacent tissue.¹⁶Oxidized regenerated cellulose is formed by dissolving the α-cellulose of decomposed wood pulp in an alkaline solution and subsequently regenerating it as a continuous fiber. This fiber is then woven into a gauze and oxidized.^17,22 Oxidized regenerated cellulose is supplied as a substrate that is flexible, malleable, and trimable.¹⁶The mechanism of hemostasis of oxidized regenerated cellulose is reportedly associated with its caustic activity.² The oxidation of cellulose produces a low-pH organic acid that reacts with blood, thus forming an artificial clot and causing platelet aggregation.¹⁸Although the manufacturer recommends the removal of oxidized regenerated cellulose once hemostasis is achieved,⁸ the product, a bioabsorbable hemostatic agent, is often left in situ within the surgical bed to prevent bleeding after surgical procedures. The biodegradation and elimination of oxidized regenerated cellulose from the tissue occurs in 2 phases.¹⁴ Polyanhydroglucuronic acid, the major functional unit of oxidized regenerated cellulose, is readily soluble. This acid is degraded extracellulary and systematically cleared from the system approximately 18 h after implantation.^13,14 The remaining fibrous residue, however, requires macrophage phagocytosis for clearance and can be observed within macrophages for at least 48 h after implantation.¹³ Unfortunately, these fibrous residues have a prolonged degradation, and their persistence for as long as 7 mo after surgery has been confirmed histologically.⁷Despite the biocompatibility of oxidized regenerated cellulose, granulomatous foreign-body reactions that imitate infection or tumor recurrence have been revealed by using noninvasive imaging techniques.^{1,11,12,15,17,18,22} Here we describe a case of peritonitis and granuloma formation secondary to the presence of oxidized regenerated cellulose after an intestinal resection to excise a colonic adenocarcinoma in an aged rhesus macaque.