Patterns of molecular and phenotypic diversity in pearl millet [<Emphasis Type="Italic">Pennisetum glaucum</Emphasis>(L.) R. Br.] from West and Central Africa and their relation to geographical and environmental parameters

Background  

The distribution area of pearl millet in West and Central Africa (WCA) harbours a wide range of climatic and environmental conditions as well as diverse farmer preferences and pearl millet utilization habits which have the potential to lead to local adaptation and thereby to population structure. The objectives of our research were to (i) assess the geographical distribution of genetic diversity in pearl millet inbreds derived from landraces, (ii) assess the population structure of pearl millet from WCA, and (iii) identify those geographical parameters and environmental factors from the location at which landraces were sampled, as well as those phenotypic traits that may have affected or led to this population structure. Our study was based on a set of 145 inbred lines derived from 122 different pearl millet landraces from WCA.     

Process optimization for the synthesis of octenyl succinyl derivative of waxy corn and amaranth starches

Modification of starch by dicarboxylic acid anhydrides to starch esters, containing both hydrophilic and hydrophobic groups are known to improve its emulsification properties, and can also be used for encapsulation after hydrolysis. Reports on the effect of process conditions on the extent of modification of starches by using n-octenyl succinic anhydride (n-OSA) are not readily available. In the present study, the process of manufacturing of OSA starches from waxy corn and amaranth starch were studied with respect to the OSA/starch ratio, pH, temperature and time of the reaction. The effects of these parameters were evaluated on the basis of degree of substitution (DS). The concluding conditions for amaranth-OSA starches was a reaction time of 6 h at 3% OSA/starch ratio at 30 °C and pH 8.0 at 25% starch concentration. For waxy corn-OSA starch, all parameters were identical except for the reaction time of 24 h. The maximum DS achieved for both the starches was 0.02. Emulsification capacity and oil absorption capacity of the OSA-modified starches were more or less similar within the parameter chosen and also independent of starch type.     

A simple method to identify supramolecules in action: Hill coefficients for exergonic self-assembly

Precise supramolecular architecture is often essential for significant function. Simple methods to reliably and rapidly demonstrate the existence of such supramolecular structure and function at relevant concentrations in complex systems are badly needed. Hill plots, describing the dependence of a signal on the n-th power of the monomer concentration, are compatible only with the identification of supramolecules that do not really exist, that is, endergonic self-assembly (Litvinchuk et al., J Am Chem Soc 2004;126:10067). Here, we show that the artificial increase in monomer concentration by chemical denaturation restores compatibility of Hill plots with exergonic self-assembly and affords Hill coefficients n > 1 for stable supramolecules. Recent rigid-rod pi-stack architecture with photosynthetic and ion channel activity is used as timely example, circular dichroism (CD) spectroscopy as method of choice for both sensitive and selective detection under relevant conditions.     

Downregulation of Keratin 76 Expression during Oral Carcinogenesis of Human,Hamster and Mouse

Background

Keratins are structural marker proteins with tissue specific expression; however, recent reports indicate their involvement in cancer progression. Previous study from our lab revealed deregulation of many genes related to structural molecular integrity including KRT76. Here we evaluate the role of KRT76 downregulation in oral precancer and cancer development.

Methods

We evaluated KRT76 expression by qRT-PCR in normal and tumor tissues of the oral cavity. We also analyzed K76 expression by immunohistochemistry in normal, oral precancerous lesion (OPL), oral squamous cell carcinoma (OSCC) and in hamster model of oral carcinogenesis. Further, functional implication of KRT76 loss was confirmed using KRT76-knockout (KO) mice.

Results

We observed a strong association of reduced K76 expression with increased risk of OPL and OSCC development. The buccal epithelium of DMBA treated hamsters showed a similar trend. Oral cavity of KRT76-KO mice showed preneoplastic changes in the gingivobuccal epithelium while no pathological changes were observed in KRT76 negative tissues such as tongue.

Conclusion

The present study demonstrates loss of KRT76 in oral carcinogenesis. The KRT76-KO mice data underlines the potential of KRT76 being an early event although this loss is not sufficient to drive the development of oral cancers. Thus, future studies to investigate the contributing role of KRT76 in light of other tumor driving events are warranted.     

Synthesis and characterization of a pH-sensitive conjugate of isoniazid with Fe3O4@SiO2 magnetic nanoparticles

The Letter describes the preparation and characterization of a conjugate of isoniazid (INH) with magnetic nanoparticles Fe₃O₄@SiO₂ 115 ± 60 nm in size. The INH molecules were attached to the surface of nanoparticles by a covalent pH-sensitive amidine bond. The conjugate was characterized by X-ray diffraction, SEM, dynamic light scattering, IR spectroscopy and microanalysis. The conjugate released isoniazid under in vitro conditions (pH = 4; 37 °C; t_1/2 ≈ 115 s). In addition, the cytotoxicity of the Fe₃O₄@SiO₂–INH conjugate was evaluated in SK-BR-3 cells using the xCELLigence system.     

Transient Receptor Potential Ankyrin 1 Receptor Activation In Vitro and In Vivo by Pro-tussive Agents: GRC 17536 as a Promising Anti-Tussive Therapeutic

Cough is a protective reflex action that helps clear the respiratory tract which is continuously exposed to airborne environmental irritants. However, chronic cough presents itself as a disease in its own right and despite its global occurrence; the molecular mechanisms responsible for cough are not completely understood. Transient receptor potential ankyrin1 (TRPA1) is robustly expressed in the neuronal as well as non-neuronal cells of the respiratory tract and is a sensor of a wide range of environmental irritants. It is fast getting acceptance as a key biological sensor of a variety of pro-tussive agents often implicated in miscellaneous chronic cough conditions. In the present study, we demonstrate in vitro direct functional activation of TRPA1 receptor by citric acid which is routinely used to evoke cough in preclinical and clinical studies. We also show for the first time that a potent and selective TRPA1 antagonist GRC 17536 inhibits citric acid induced cellular Ca⁺² influx in TRPA1 expressing cells and the citric acid induced cough response in guinea pigs. Hence our data provides a mechanistic link between TRPA1 receptor activation in vitro and cough response induced in vivo by citric acid. Furthermore, we also show evidence for TRPA1 activation in vitro by the TLR4, TLR7 and TLR8 ligands which are implicated in bacterial/respiratory virus pathogenesis often resulting in chronic cough. In conclusion, this study highlights the potential utility of TRPA1 antagonist such as GRC 17536 in the treatment of miscellaneous chronic cough conditions arising due to diverse causes but commonly driven via TRPA1.     

Hybrid molecules of carvacrol and benzoyl urea/thiourea with potential applications in agriculture and medicine

Benzoyl phenyl urea, a class of insect growth regulator's acts by inhibiting chitin synthesis. Carvacrol, a naturally occurring monoterpenoid is an effective antifungal agent. We have structurally modified carvacrol (2-methyl-5-[1-methylethyl] phenol) by introducing benzoylphenyl urea linkage. Two series of benzoylcarvacryl thiourea (BCTU, 4a-f) and benzoylcarvacryl urea (BCU, 5a-f) derivatives were prepared and characterized by elemental analysis, IR, (1)H and (13)C NMR and Mass spectroscopy. Derivatives 4b, 4d, 4e, 4f and 5d, 5f showed comparable insecticidal activity with the standard BPU lufenuron against Dysdercus koenigii. BCTU derivatives 4c, 4e and BCU 5c showed good antifungal activity against phytopathogenic fungi viz. Magnaporthe grisae, Fusarium oxysporum, Dreschlera oryzae; food spoilage yeasts viz. Debaromyces hansenii, Pichia membranifaciens; and human pathogens viz. Candida albicans and Cryptococcus neoformans. Compounds 5d, 5e and 5f showed potent activity against human pathogens. Moderate and selective activity was observed for other compounds. All the synthesized compounds were non-haemolytic. These compounds have potential application in agriculture and medicine.     

Distribution of transition metal ions in multiple forms of Methanosarcina hydrogenase

There were significant levels of in vitro hydrogenase activity in Methanosarcina strains. The multiple forms of hydrogenase were observed in cell free extracts of cells grown on methanol. Strains having poor growth on H₂ : CO₂ had four forms while strains having normal growth on all substrates contained two forms of hydrogenase. These multiple forms differ in their charges as well as in their composition of transition metal ions. The strain having normal growth showed higher incorporation of ⁶³Ni²⁺ and ⁶⁵Zn²⁺. Both hydrogenases, A and D, of strain P₃ had methylviologen and F₄₂₀-reducing activity and contained Zn²⁺ and Co²⁺ respectively. Hydrogenases A and D of strains P₁ and P₄ also had similar characteristics whereas hydrogenases B and C had only methylviologen reducing activity.     

Purification and characterization of putative alkaline [Ni-Fe] hydrogenase from unicellular marine green alga, Tetraselmis kochinensis NCIM 1605

Hydrogenase enzyme from the unicellular marine green alga Tetraselmis kochinensis NCIM 1605 was purified 467 fold to homogeneity. The molecular weight was estimated to be approximately 89kDa by SDS-PAGE. This enzyme consists of two subunits with molecular masses of approximately 70 and approximately 19kDa. The hydrogenase was found to contain 10g atoms of Fe and 1g of atom of Ni per mole of protein. The specific activity of hydrogen evolution was 50micromol H(2)/mg/h of enzyme using reduced methyl viologen as an electron donor. This hydrogenase enzyme has pI value approximately 9.6 representing its alkaline nature. The absorption spectrum of the hydrogenase enzyme showed an absorption peak at 425nm indicating that the enzyme had iron-sulfur clusters. The total of 16 cysteine residues were found per mole of enzyme under the denaturing condition and 20 cysteine residues in reduced denatured enzyme indicating that it has two disulfide bridges.