Identification of Virulent Isolates of the Entomopathogenic Fungus Nomuraea Rileyi (F) Samson for the Management of Helicoverpa Armigera and Spodoptera Litura

Eleven geographical isolates of the entomopathogenic fungus Nomuraea rileyi (Farlow) Samson of Helicoverpa armigera (Hubner)/Spodoptera litura (Fabricius) origin were studied for efficacy against the two host insects. Laboratory bioassays at a concentration of 2 x 10(8) conidia ml(-1) indicated that N. rileyi isolates of S. litura origin were better in terms of time taken for mycosis and mortality in both the test larvae: S. litura (77-80% mortality in 7 days) and H. armigera (79-85% in 8 days). Among the isolates of S. litura origin, geographical isolates from Hyderabad and Karimnagar were superior in terms of high percent kill as well as 100% germination of conidia within 48 h. Fastest germination was observed with Karimnagar isolate followed by Hyderabad isolate. Conidial yield was highest on barley-carrot extract-yeast extract medium. However in terms of material cost, barley-yeast extract medium was the lowest. The Karimnagar isolate of S. litura origin gave the highest conidial yield on barley-yeast extract medium. Chitinolytic enzyme profiles of different isolates revealed polymorphism in all the isolates from S. litura origin. Overall among the parameters studied the best traits were found in the Karimnagar isolate of S. litura origin.     

Resonance Raman spectroscopic studies in copper reconstituted and hybrid hemoglobins: probe into subunit heterogeneity

Copper reconstituted hemoglobin (CuHb), copper containing T-state hybrid hemoglobins like alpha2(Ni)beta2(Cu), and alpha2(Cu)beta2(Ni), and intermediate R-state hybrids like alpha2(CO-Fe)beta2(Cu) and alpha2(Cu)beta2(Fe-CO) are studied using resonance Raman (RR) spectroscopy at two different excitation wavelengths. The high frequency RR region in CuHb indicates the presence of both 4- and 5-coordinate forms of Cu(II). In hybrid Hbs, the presence of two distinct metal ion environments within one particular subunit is evident. This is also consistent with previous findings using EPR spectroscopy and sulfydryl reactivity studies on these hybrid Hbs. The low frequency RR region on these copper derivatives of HbA further suggests the existence of two different heme moieties within the subunit.     

Do younger women with non-metastatic and non-inflammatory breast carcinoma have poor prognosis?

Background  

Controversy abounds over whether breast cancer in younger women is more aggressive than those in older. The aim of the study was to assess the influence of age on long-term survival of women with breast carcinoma.     

Uncommon presentation of a common tachycardia

We describe a patient with an implanted pacemaker for impaired AV conduction who presented with an incessant tachycardia. EP study showed that the tachycardia was atrioventricular nodal reentrant tachycardia (AVNRT) with repeated spontaneous initiation because of poor or absent antegrade fast pathway conduction. Slow pathway ablation was successful in terminating the tachycardia and making it non-inducible.     

Stimulation of HIV-1 minus strand strong stop DNA transfer by genomic sequences 3' of the primer binding site

The mechanism of human immunodeficiency virus 1 (HIV-1) minus strand transfer was examined using a genomic RNA sequence-based donor-acceptor template system. The donor RNA, D199, was a 199-nucleotide sequence from the 5'-end of the genome to the primer binding site (PBS) and shared 97 nucleotides of homology with the acceptor RNA. To investigate the influence of RNA structure on transfer, a second donor RNA, D520, was generated by extending the 3'-end of D199 to include an additional 321 nucleotides of the genome. The position of priming, length of homology with the acceptor, and length of cDNA synthesized were identical with the two donors. Interestingly, at 200% NC coating, donor D520 yielded a transfer efficiency of about 75% compared with about 35% with D199. A large proportion of the D520 promoted transfers occurred after the donor RNA was copied to the end. Analysis of donor RNA cleavage, the acceptor invasion site and R homology requirements indicated that transfers with D520 involved a similar but more efficient acceptor invasion mechanism compared with D199. RNA structure probing by RNase T1 and the RT pause profile during synthesis indicated conformational differences between D199 and D520 in the starting structure, and in dynamic structures formed during synthesis within the R region. Overall observations suggest that regions 3' of the primer binding site influence the conformation of the R region of D520 to facilitate steps that promote strand transfer.     

Intermediacy of poly(L-proline) II and beta-strand conformations in poly(L-lysine) beta-sheet formation probed by temperature-jump/UV resonance Raman spectroscopy

Ultraviolet resonance Raman spectroscopy (UVRR) in combination with a nanosecond temperature jump (T-jump) was used to investigate early steps in the temperature-induced alpha-helix to beta-sheet conformational transition of poly(L-lysine) [poly(K)]. Excitation at 197 nm from a tunable frequency-quadrupled Ti:sapphire laser provided high-quality UVRR spectra, containing multiple conformation-sensitive amide bands. Although un-ionized poly(K) (pH 11.6) is mainly alpha-helical below 30 degrees C, there is a detectable fraction (approximately 15%) of unfolded polypeptide, which is mainly in the poly(L-proline) II (PPII) conformation. However, deviations from the expected amide I and II signals indicate an additional conformation, suggested to be beta-strand. Above 30 degrees C un-ionized poly(K) forms a beta-sheet at a rate (minutes) which increases with increasing temperature. A 22-44 degrees C T-jump is accompanied by prompt amide I and II difference signals suggested to arise from a rapid shift in the PPII/beta-strand equilibrium. These signals are superimposed on a subsequently evolving difference spectrum which is characteristic of PPII, although the extent of conversion is low, approximately 2% at the 3 micros time limit of the experiment. The rise time of the PPII signals is approximately 250 ns, consistent with melting of short alpha-helical segments. A model is proposed in which the melted PPII segments interconvert with beta-strand conformation, whose association through interstrand H-bonding nucleates the formation of beta-sheet. The intrinsic propensity for beta-strand formation could be a determinant of beta-sheet induction time, with implications for the onset of amyloid diseases.     

2D Crystals Significantly Enhance the Performance of a Working Fuel Cell

2D atomic crystals such as single layer graphene (SLG) and hexagonal boron nitride (hBN) have been shown to be “unexpectedly permeable” to hydrogen ions under ambient conditions with the proton conductivity rising exponentially with temperature. Here, the first successful addition of SLG made by a chemical vapor deposition (CVD) method is shown to an operational direct methanol fuel cell significantly enhancing the performance of the cell once the temperature is raised above 60 °C, the temperature at which the proton conductivity of SLG is higher than the Nafion membrane on which it is mounted. Above this temperature, the resistance to proton transport of the system is not affected by the graphene but the barrier properties of graphene inhibit methanol crossover. The performance of the fuel cell is shown to increase linearly with coverage of SLG above this temperature. Results show that the maximum power density is increased at 70 °C by 45% in comparison to the standard membrane electrode assembly without graphene. In addition, a membrane with CVD hBN shows enhanced performance across the entire temperature range due to better proton conductivity at lower temperatures.     

Antibiotic intervention redisposes bacterial interspecific interacting dynamics in competitive environments

Interspecific interaction happens frequently among bacterial species and can promote the colonization of polymicrobial community in various environments. However, it is not clear whether the intervention of antibiotics, which is a common therapeutic method for infectious disease, will influence the interacting dynamics of different pathogenic bacteria. By using the frequently co-isolated bacteria Pseudomonas aeruginosa and Staphylococcus aureus as models, here we identify an antibiotic-determined mutual invasion relationship between bacterial pathogens. We show that although P. aeruginosa has a significant intrinsic competitive advantage over S. aureus by producing the quorum-sensing (QS)-controlled anti-staphylococcal molecules, methicillin-resistant S. aureus (MRSA) can inhibit neighbouring P. aeruginosa in the presence of subinhibitory aminoglycoside antibiotics (e.g. streptomycin) to P. aeruginosa. Importantly, subinhibitory streptomycin decreases the expression of QS-regulated genes in P. aeruginosa and thus relieves the survival stress of MRSA brought by P. aeruginosa. On the other side, the iron-uptake systems and pathogenicity of MRSA can be enhanced by the extracellular products of streptomycin-treated P. aeruginosa. Therefore, this study provides an explanation for the substitution of dominant species and persistent coexistence of bacterial pathogens in the host with repeated antibiotic therapies and contributes to further understanding the pathogenesis of chronic polymicrobial infections.     

Pumpkin (Cucurbita ficifolia Bouché) extract attenuate the adipogenesis in human mesenchymal stem cells by controlling adipogenic gene expression

Prevention and management of obesity through dietary modification is one of the top way to trim down its consequences. Development of adipose tissue requires the differentiation of less specialized cells, such as human mesenchymal stem cells (hMSCs), into adipocytes. Since food constituents play a major role in the cell differentiation and proliferation, we sought to determine if various extracts of Cucurbita ficifolia (C. ficifolia), could affect the adipogenic differentiation of hMSCs. Flow cytometry analysis with quantitative and qualitative Nile red, and quantitative PCR methods were employed to evaluate the C. ficifolia effect on hMSCs adipogenesis. Results revealed that, chloroform extract exhibits significant adipogenic inhibition than that of hexane and methanol extracts. Chloroform extract treated cells display the down-regulation of ADIPOQ, FABP4, PPARGC1A, CEBPB & LPL and up-regulation of ACACB & CEBPA genes. Further, various phytoconstituents present in the chloroform extract of C. ficifolia were analyzed though LC-MS and GC-MS. Our results indicates that chloroform extract of C. ficifolia might be used as a food supplement to control obesity and its related consequences.     

Early events in apomyoglobin unfolding probed by laser T-jump/UV resonance Raman spectroscopy

Early events in the unfolding of apomyoglobin are studied with time-resolved ultraviolet resonance Raman (UVRR) spectroscopy coupled to a laser-induced temperature jump (T-jump). The UVRR spectra provide simultaneous probes of the aromatic side-chain environment and the amide backbone conformation. The amide bands reveal helix melting, with relaxation times of 70 and 16 micros at pH 5.5 and 4, respectively, in reasonable agreement with previously reported amide I' FTIR/T-jump relaxations (132 and 14 micros at pD 5.5 and 3). The acceleration at pH 4 is consistent with destabilization of the hydrophobic AGH core of the protein via protonation of a pair of buried histidines. The same relaxation times are found for intensity loss by the phenylalanine F12 band, signaling solvent exposure of the phenyl rings. There are seven Phe residues, distributed throughout the protein; they produce a global response, parallel to helix melting. Relaxation of the tryptophan W16 intensity also parallels helix melting at pH 5.5 but is twice as fast, 7 micros, at pH 4. The pH 5.5 signal arises from Trp 7, which is partially solvent-exposed, while the pH 4 signal arises from the buried Trp 14. Thus, Trp 14 is exposed to the solvent prior to helix melting of the AGH core, suggesting initial displacement of the A helix, upon which Trp 14 resides. All of the UVRR signals show a prompt response, within the instrument resolution (approximately 60 ns), which accounts for half of the total relaxation amplitude. This response is attributed to solvent penetration into the protein, possibly convoluted with melting of hydrated helix segments.