A comparative analyses of morphological variations,phagocytosis and generation of cytotoxic agents in flow cytometrically isolated hemocytes of Indian molluscs

A comparative analyses of hemocytes of molluscs, Pila globosa (Gastropoda: Prosobranchia), Bellamya bengalensis (Gastropoda: Prosobranchia) and Lamellidens marginalis (Bivalvia: Eulamellibranchiata) were carried out for morphotype and subpopulation identification, analyses of phagocytosis and generation of cytotoxic agents. Flow cytometry and microscopic analyses of hemocytes revealed the existence of agranulocytes (blast like cells, round hyalinocytes and spindle hyalinocytes), semigranulocytes (semigranular asterocytes and round semigranulocytes) and granulocytes (round granulocytes, spindle granulocytes and granular asterocytes) as three morphotypes. In P. globosa, granulocytes and semigranulocytes and in B. bengalensis granulocytes and agranulocytes are the chief phagocytes and major producers of superoxide anion and nitric oxide. In L. marginalis, granulocytes were identified as principal phagocytes with prominent activity of superoxide anion and nitric oxide. Highest activity of phenoloxidase was recorded in the agranulocytes of P. globosa with moderate activities among other morphotypes of all three species. Differential result may be due to species specific response, non-identical habitat preference and related adaptation of the species to their different ecological niches.     

Mycobacterium tuberculosis secretory proteins CFP-10, ESAT-6 and the CFP10:ESAT6 complex inhibit lipopolysaccharide-induced NF-kappaB transactivation by downregulation of reactive oxidative species (ROS) production

Mycobacterium tuberculosis (Mtb) causes death of 2-3 million people annually and is considered one of the most successful intracellular pathogens to persist inside the host macrophage. Recent studies have implicated the role of RD-1 region of Mtb genome in the mycobacterial pathogenesis. The role of RD-1-encoded secretory proteins of Mtb in modulation of macrophage function has not been investigated in detail. Here we show that RD-1 encoded two major secretory proteins, namely, culture filtrate protein-10 kDa (CFP-10) and early secreted antigenic target-6 kDa (ESAT-6), and their 1:1 CFP-10:ESAT6 complex inhibit production of reactive oxidative species (ROS) in RAW264.7 cells. These proteins also downregulated the bacterial lipopolysaccharide (LPS)-induced ROS production, which, in turn, downregulated LPS-induced nuclear factor-kappaB (NF-kappaB) p65 DNA-binding activity, as well as inhibited the NF-kappaB-dependent reporter gene (chloramphenicol acetyl transferase) expression in the treated macrophages. Moreover, addition of N-acetyl cysteine, which is a scavenger of ROS, also inhibited LPS-induced reporter gene expression by scavenging the ROS, thereby preventing NF-kappaB transactivation. These studies indicate that the secretory proteins CFP-10, ESAT-6 and the CFP10:ESAT6 complex of Mtb can inhibit LPS-induced NF-kappaB-dependent gene expression via downregulation of ROS production.     

Pathological Changes in Mermithid Nematode Infected Stictochironomus polystictus (Kieffer) (Diptera,Chironomidae, Chironominae)

Mermithid nematodes cause morphological and sexual anomalies in the pupae and adults of Stictochironomus polystictus (Kieffer). The parasite-induced changes resulted in the development of three types of intersexes. Structural alterations of adult males were variation of antennal length, appearance of antenna and number of flagellomeres, VIIIth abdominal segment, genitalia and associated appendages while in pupae, the length of antennal sheath and genital sac. However, the midge larvae infected with nematodes did not show any abnormality in morphological features. These entomopathogenic worms infecting male chironomids can feminize them and induce them to adopt a female behavior and return to water. So the worms apparently benefit from behavioral changes of the infected host, thereby reaching their abode where new hosts for its juveniles may be encountered. Since parasitized insects are usually castrated by worms before the beginning of the morphological changes, the behavioral alterations do not make additional fitness to the host.     

Extraction and characterization of biocompatible hydroxyapatite from fresh water fish scales for tissue engineering scaffold

In bone tissue engineering, porous hydroxyapatite (HAp) is used as filling material for bone defects, augmentation, artificial bone graft and scaffold material. The present paper compares the preparation and characterization of HAp from fish scale (FS) and synthetic body fluid (SBF) solution. Thermo gravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and particle size analysis of the samples have been performed. The analysis indicates that synthesized HAp consists of sub-micron HAp particle with Ca/P ratio corresponding to FS and SBF 1.62 and 1.71, respectively. MTT assay and quantitative DNA analysis show growth and proliferation of cells over the HA scaffold with the increase in time. The shape and size (morphology) of mesenchymal stem cells after 3 days show a transition from rounded shape to elongated and flattened shape expressing its spreading behavior. These results confirm that HAp bio-materials from fish scale are physico-chemically and biologically equivalent to the chemically synthesized HAp from SBF. Biological HAp, thus, possesses a great potential for conversion of industrial by-product into highly valuable compounds using simple effective and novel processes.     

Manipulation of inositol metabolism for improved plant survival under stress: a “network engineering approach”

Emergence of high-throughput sequencing tools and omics technologies paved the way for systems biology in last decade. While we have started to look at the biology of the plant in a more unified manner, the integration of such knowledge in agricultural biotechnology has become an arena of potential interest. The network of several central molecules operating in various life and developmental processes are now more adequately known, and fine tuning of such molecule pools, if connected to stress response, can result in enhanced stress tolerance of plants.This review interprets the potential of manipulation of myo-inositol and its derivatives in generation of transgenic crop plants. Being a molecule of central importance in plant life, inositol is connected to numerous life processes. The exploration of such pathways indicates that inositol itself and many of its derivatives can impart abiotic stress tolerance (against salinity, dehydration, chilling or oxidative stress) to plants when overexpressed. We propose that engineering inositol metabolic network is a potential approach towards stress-tolerant transgenic crop plant generation and thus its exploitation in agricultural biotechnology is the call of time.     

Human papillomavirus E6 and E7 oncoproteins as risk factors for tumorigenesis

Human papillomavirus (HPV) is small, double-stranded DNA virus that infects mucosal and cutaneous epithelial tissue. HPV is sexually transmitted and the viral DNA replicates extrachromosomally. The virus is non-enveloped and has an icosahedral capsid. There are approximately 118 types of HPV, which are characterized as high-risk or lowrisk types. High-risk HPVs cause malignant transformation while the low-risk ones cause benign warts and lesions. The expression of E6 and E7 is normally controlled during the normal viral life cycle when viral DNA replicates extrachromosomally. HPV E6 and E7 oncoproteins are overexpressed when the viral genome integrates into the host DNA. Deregulated overexpression of E6 and E7 oncoproteins can cause several changes in cellular pathways and functions leading to malignant transformation of cells and tumorigenesis. In this review, we focus on several cellular mechanisms and pathways that are altered in the presence of E6 and E7, the target proteins of E6 and E7 inside the host cell and how they contribute to the development of the transformed phenotype.     

Evolutionary complexities of swine flu H1N1 gene sequences of 2009

A recently emerged novel influenza A (H1N1) virus continues to spread globally. The pandemic caused by this new H1N1 swine influenza virus presents an opportunity to analyze the evolutionary significance of the origin of the new strain of swine flu. Our study clearly suggests that strong purifying selection is responsible for the evolution of the novel influenza A (H1N1) virus among human. We observed that the 2009 viral sequences are evolutionarily widely different from the past few years’ sequences. Rather, the 2009 sequences are evolutionarily more similar to the most ancient sequence reported in the NCBI Influenza Virus Resource Database collected in 1918. Analysis of evolutionary rates also supports the view that all the genes in the pandemic strain of 2009 except NA and M genes are derived from triple reassorted swine viruses. Our study demonstrates the importance of using complete-genome approach as more sequences will become available to investigate the evolutionary origin of the 1918 influenza A (H1N1) swine flu strain and the possibility of future reassortment events.