胎盘间充质干细胞治疗小鼠烫伤愈合的相关研究

目的:观察胎盘间充质干细胞对TGF-β1/Smad信号通路的调控作用,探讨胎盘间充质干细胞对烫伤愈合及瘢痕形成的影响。方法:构建小鼠烫伤模型,注射人胎盘间充质干细胞(hPMSCs),荧光显微镜观察小鼠创伤皮肤组织中hPMSCs细胞的存活情况;HE和Masson染色观察小鼠创伤皮肤的变化;Western blot检测观察创伤皮肤TGF-β1、p-Smad3、Smad7、α-SMA、collagen I、Collagen III蛋白表达变化。结果:注射hPMSCs细胞后,小鼠创伤面积逐渐减小,创伤愈合率逐渐增加;hPMSCs细胞分布在小鼠创伤皮肤组织中,存活状况较好。进一步研究发现烫伤模型组皮肤表层细胞受损脱落,真皮层组织疏松,毛囊、皮脂腺等附属器坏死,可见明显的毛细血管扩张,并伴有炎性细胞渗出,同时可见大量的成纤维细胞增生和胶原纤维形成;注射hPMSCs细胞治疗后,病理改变、纤维增生和胶原形成明显减轻;此外,烫伤模型组创伤皮肤组织中TGF-β1、p-Smad3表达明显上调,Smad7蛋白表达明显下调,α-SMA、collagen I、Collagen III表达明显上调。经hPMSCs细胞治疗后,TGF-β1、p-Smad3蛋白表达明显下调,Smad7蛋白表达明显上调,α-SMA、collagen I、Collagen III蛋白表达明显下调。结论:胎盘间充质干细胞可能通过抑制TGF-β1/Smad信号通路,发挥促进烫伤愈合且抑制瘢痕形成的作用。     

Coassemble dopamine and GHK tripeptide into fluorescent nanoparticles for pH sensing

Fluorescent nanostructures have been widely applied to biomedical researches and clinical diagnosis such as biolabeling/imaging/sensing and have even acted as therapy reagents. Peptide‐based fluorescent nanostructures attract recent interest from biomedical researchers. Inspired by the natural existence of GHK‐Cu complex with a growth factor‐like effect in human blood, here we have developed a novel approach for designing nanosensors through the co‐assembling of two kinds of biomolecules. By making best use of both π‐π stacking between carbon rings and the easy‐oxidation property of an important transmitter molecule, dopamine (DA), we successfully built up a supersensitive and robust fluorescent pH nanosensor by co‐assembling oxidized DA (DA_ox) with a tripeptide GHK. The GHK‐DA_ox nanostructures have a quantum yield of 20.82%, which might be the brightest one among all the current co‐assembling structures merely through unmodified biomolecules. We envision this approach could open a new avenue for not only hybrid nanostructure construction, but also may inspire the bioengineering of in vivo luminescent probes.     

Effect of host plant on cornucopia of mango fruit flies (Diptera: Tephritidae) and their triumphant management in context of climate change

A study was performed to assess the preference of fourteen mango cultivars for fruit flies and their management by bagging. So the choice of Tephritid flies to mango cultivars during fruiting phase is crucial. Fourteen different cultivars of mango viz., ‘Dusehri’, ‘Malda’, ‘Langra’ early cultivars, ‘Chaunsa’, ‘Fajri Klan’, ‘Sensation’ medium whereas ‘Sanglakhi’, ‘Retaul-12’, ‘Mehmood Khan’, ‘Tukhmi’, ‘Kala Chaunsa’, ‘Chitta Chaunsa’, ‘Dai Wala’ and ‘Sobey De Ting’ late cultivars were assessed for their suitability for fruit flies. The results indicate that the population density of fruit flies was higher on late cultivars like ‘Sanglakhi’ (20.61 percent), ‘Mehmood Khan’ (20.22 percent) and ‘Reutal-12’ (19.92 percent) were proved to be highly susceptible to fruit flies. Among these the cultivar ‘Reutal-12’ was selected being commercial and future cultivar for the management of fruit flies through bagging. The results reported that the attack of tephritid fruit flies and other insect pests were zero in bagged fruits as compared with control. It was further recorded that the bagged fruits has maximum average fruit weight i.e. 203.50 and 197.83 g per fruit was noted in those treatments where butter paper bag and brown paper bag was wrapped with better coloration as compared with un-bagged fruit with 159.5 g per fruit. Similarly, on an average fruit length were more i.e. 90.17, 91.33 mm in bagged fruit and 85.33 in un-bagged fruits. Furthermore, bagged fruits have zero incidence of disease with reduced fruit crack, fruit sunburn, mechanical damage, bird damage, fruit blemished and agrochemical residues on the fruit. So, it is concluded that the special attention should be given on ‘Reutal-12’ for the management of fruit flies when devising an IPM program for the control of fruit flies. Further, bagging has proved to be the good agricultural practices for the production of quality mango.     

Envenomation and the bite rate by venomous snakes in the kingdom of Saudi Arabia over the period (2015–2018)

Snakebite being medical emergency and known cause for increased mortality needs assessment and treatment on high-priority bases, even in patients of snakebite who appear fine initially. The current retrospective study presents the snake bites in Saudi Arabia from 2015 to 2018 reported by General Administration of Statistics and Information, Ministry of Health, Kingdom of Saudi Arabia. The data presented in the current study, was extracted, analyzed, and reported after getting ethical approval from institutional committee. Totally, 14,679 cases of snakebites were reported during the four-year study period, with a higher prevalence in males (80%) in their productive age. Most patients were within the age group between 25 and 44 followed by 44 to 64 years. The majority of snakebite affected inhabitants were reported from farms of the rural areas, commonly during night hours of spring and summer seasons when snakes are very active. Only 36 (0.24%) patients out of 14,679 were reported dead and 14,643 (99.63%) were discharged after the treatment. Awareness among the general public should be encouraged and early diagnosis and usage of proper snake antivenoms could be life-saving. The delay in appropriate treatment can lead to significant morbidity and mortality.     

Evidence for a synergistic effect of post‐translational modifications and genomic composition of eEF‐1α on the adaptation of Phytophthora infestans

Genetic variation plays a fundamental role in pathogen''s adaptation to environmental stresses. Pathogens with low genetic variation tend to survive and proliferate more poorly due to their lack of genotypic/phenotypic polymorphisms in responding to fluctuating environments. Evolutionary theory hypothesizes that the adaptive disadvantage of genes with low genomic variation can be compensated for structural diversity of proteins through post‐translation modification (PTM) but this theory is rarely tested experimentally and its implication to sustainable disease management is hardly discussed. In this study, we analyzed nucleotide characteristics of eukaryotic translation elongation factor‐1α (eEF‐lα) gene from 165 Phytophthora infestans isolates and the physical and chemical properties of its derived proteins. We found a low sequence variation of eEF‐lα protein, possibly attributable to purifying selection and a lack of intra‐genic recombination rather than reduced mutation. In the only two isoforms detected by the study, the major one accounted for >95% of the pathogen collection and displayed a significantly higher fitness than the minor one. High lysine representation enhances the opportunity of the eEF‐1α protein to be methylated and the absence of disulfide bonds is consistent with the structural prediction showing that many disordered regions are existed in the protein. Methylation, structural disordering, and possibly other PTMs ensure the ability of the protein to modify its functions during biological, cellular and biochemical processes, and compensate for its adaptive disadvantage caused by sequence conservation. Our results indicate that PTMs may function synergistically with nucleotide codes to regulate the adaptive landscape of eEF‐1α, possibly as well as other housekeeping genes, in P. infestans. Compensatory evolution between pre‐ and post‐translational phase in eEF‐1α could enable pathogens quickly adapting to disease management strategies while efficiently maintaining critical roles of the protein playing in biological, cellular, and biochemical activities. Implications of these results to sustainable plant disease management are discussed.     

Establishment of rat brain endothelial cells susceptible to rat cytomegalovirus ALL-03 infection

Endothelial cells have been implicated as key cells in promoting the pathogenesis and spread of cytomegalovirus (CMV) infection. This study describes the isolation and culture of rat brain endothelial cells (RBEC) and further evaluates the infectious potential of a Malaysian rat CMV (RCMV ALL-03) in these cultured cells. Brain tissues were mechanically fragmented, exposed to enzymatic digestion, purified by gradient density centrifugation, and cultured in vitro. Morphological characteristics and expression of von Willebrand factor (factor VIII-related antigen) verified the cells were of endothelial origin. RBEC were found to be permissive to the virus by cytopathic effects with detectable plaques formed within 7 d of infection. This was confirmed by electron microscopy examination which proved the existence of the viral particles in the infected cells. The susceptibility of the virus to these target cells under the experimental conditions described in this report provides a platform for developing a cell-culture-based experimental model for studies of RCMV pathogenesis and allows stimulation of further studies on host cell responses imposed by congenital viral infections.     

KINETIC STUDIES OF L-ASPARAGINASE FROM Penicillium digitatum

L-Asparaginase is an enzyme used in the treatment of acute lymphoblastic leukemia and other related malignancies. Its further use includes reduction of asparagine concentration in food products, which may lead to formation of acrylamide. Currently bacterial asparaginase is produced at industrial scale, but the enzyme isolated from bacterial origin is often associated with adverse reactions. These side effects require development of asparaginase from alternative sources. In the present study, Penicillium digitatum was explored for the production of extracellular L-asparaginase using modified Czapek–Dox media. The enzyme was purified about 60.95-fold and then kinetic study showed that the Km value of the enzyme was 1 × 10^?5 M. The optimum pH and temperature for the enzyme were 7.0 and 30°C, respectively. The optimum incubation period for L-asparaginase was 15 min. This work concludes that this enzyme can be a suitable candidate due to its strong kinetic properties, and further research can usher into development of asparaginase formulation from fungal origin with less adverse effects.     

Biggest challenges in bioinformatics

The third Heidelberg Unseminars in Bioinformatics (HUB) was held on 18th October 2012, at Heidelberg University, Germany. HUB brought together around 40 bioinformaticians from academia and industry to discuss the ‘Biggest Challenges in Bioinformatics’ in a ‘World Café’ style event.