An ab initio study of di- and trifluorobenzene–benzene complexes as relevant to carbonic anhydrase II–drug interactions

Ab initio calculations at the MP2/6-31G* level have shown that variously substituted di- and trifluorobenzenes form non-covalent complexes with benzene that adopt either aromatic–aromatic or H---F binding, the choice being determined by the pattern of fluorination. The binding energies of these structures are from 3.4 to 4.5 kcal mol^–1. This range is large enough to account for observed variations in the binding affinity of a library of fluoroaromatic inhibitors of carbonic anhydrase. This enzyme has an aromatic amino acid at a central position in the active site. The diverse modes of binding of the dimers also suggest that aggregates of fluorobenzenes might adopt specified 3-dimensional shapes in the solid state. Figure Observed structure for 1,2-difluorobenzene     

Molecular profiling of fungal assemblages in the healthy and infected roots of <Emphasis Type="Italic">Decalepis arayalpathra</Emphasis> (J. Joseph &amp; V. Chandras) Venter,an endemic and endangered ethnomedicinal plant from Western Ghats,India

Decalepis arayalpathra, an endangered, endemic ethnomedicinal plant from southern Western Ghats, India, is targeted for its aromatic and medicinal properties. This study aimed at to identify fungal endophyte populations associated with healthy and diseased roots of this perennial shrub. Healthy and rotted root samples of D. arayalpathra were collected, fungal endophytes assemblages were identified both by culture-dependent and culture-independent approaches, further sequenced and the retrieved sequences were analysed with the reference sequences in GenBank to know their phylogenetic relationships. Analysis of the ITS rDNA region generated 24 different Ascomycota and three Basidiomycota taxa. Trichoderma sp. was most abundant in healthy and diseased root samples, while Penicillium and Aspergillus were confined to healthy roots. Furthermore, Fusarium solani, Fusarium oxysporum and Mucor velutinosus were found to be the most frequent fungi identified from the rotted root samples, thus substantiated to be the cause for D. arayalpathra decline in the wild. Interestingly, the strains assigned to Fusarium sp. were isolated from diseased roots showing typical clearly visible symptoms, such as a severe brown discolouration on the taproot. Molecular profiling of all the pure fungal isolates, viz., Trichoderma, Penicillium, Aspergillus, Fusarium and Mucor, revealed high sequence similarities (≥ 98 %) to corresponding reference sequences. Sequencing of Trichoderma pure cultures isolated from healthy and diseased roots revealed sequence similarities to Trichoderma harzianum, T. hamatum, T. koningiopsis, T. asperellum, T. pubescens and Hypocrea sp. This confirms the morphological examinations, as Hypocrea is the teleomorph stage of Trichoderma sp. This study signifies the first work pertaining to the taxonomy of the fungal endophytic community of D. arayalpathra, and the results reported in this work may help to ascertain the cause of root rot disease often perceived in D. arayalpathra. Also, it could be useful to identify the promising endophytic communities against the root rot diseases occurring in D. arayalpathra.     

Pseudomonas sp. to Sphingobium indicum: a journey of microbial degradation and bioremediation of Hexachlorocyclohexane

The unusual process of production of hexachlorocyclohexane (HCH) and extensive use of technical HCH and lindane has created a very serious problem of HCH contamination. While the use of technical HCH and lindane has been banned all over the world, India still continues producing lindane. Bacteria, especially Sphingomonads have been isolated that can degrade HCH isomers. Among all the bacterial strains isolated so far, Sphingobium indicum B90A that was isolated from HCH treated rhizosphere soil appears to have a better potential for HCH degradation. This conclusion is based on studies on the organization of lin genes and degradation ability of B90A. This strain perhaps can be used for HCH decontamination through bioaugmentation.     

Teaching cardiac electrophysiology modeling to undergraduate students: laboratory exercises and GPU programming for the study of arrhythmias and spiral wave dynamics

As part of a 3-wk intersession workshop funded by a National Science Foundation Expeditions in Computing award, 15 undergraduate students from the City University of New York(1) collaborated on a study aimed at characterizing the voltage dynamics and arrhythmogenic behavior of cardiac cells for a broad range of physiologically relevant conditions using an in silico model. The primary goal of the workshop was to cultivate student interest in computational modeling and analysis of complex systems by introducing them through lectures and laboratory activities to current research in cardiac modeling and by engaging them in a hands-on research experience. The success of the workshop lay in the exposure of the students to active researchers and experts in their fields, the use of hands-on activities to communicate important concepts, active engagement of the students in research, and explanations of the significance of results as the students generated them. The workshop content addressed how spiral waves of electrical activity are initiated in the heart and how different parameter values affect the dynamics of these reentrant waves. Spiral waves are clinically associated with tachycardia, when the waves remain stable, and with fibrillation, when the waves exhibit breakup. All in silico experiments were conducted by simulating a mathematical model of cardiac cells on graphics processing units instead of the standard central processing units of desktop computers. This approach decreased the run time for each simulation to almost real time, thereby allowing the students to quickly analyze and characterize the simulated arrhythmias. Results from these simulations, as well as some of the background and methodology taught during the workshop, is presented in this article along with the programming code and the explanations of simulation results in an effort to allow other teachers and students to perform their own demonstrations, simulations, and studies.     

A Novel Telomerase Activator Suppresses Lung Damage in a Murine Model of Idiopathic Pulmonary Fibrosis

The emergence of diseases associated with telomere dysfunction, including AIDS, aplastic anemia and pulmonary fibrosis, has bolstered interest in telomerase activators. We report identification of a new small molecule activator, GRN510, with activity ex vivo and in vivo. Using a novel mouse model, we tested the potential of GRN510 to limit fibrosis induced by bleomycin in mTERT heterozygous mice. Treatment with GRN510 at 10 mg/kg/day activated telomerase 2–4 fold both in hematopoietic progenitors ex vivo and in bone marrow and lung tissue in vivo, respectively. Telomerase activation was countered by co-treatment with Imetelstat (GRN163L), a potent telomerase inhibitor. In this model of bleomycin-induced fibrosis, treatment with GRN510 suppressed the development of fibrosis and accumulation of senescent cells in the lung via a mechanism dependent upon telomerase activation. Treatment of small airway epithelial cells (SAEC) or lung fibroblasts ex vivo with GRN510 revealed telomerase activating and replicative lifespan promoting effects only in the SAEC, suggesting that the mechanism accounting for the protective effects of GRN510 against induced lung fibrosis involves specific types of lung cells. Together, these results support the use of small molecule activators of telomerase in therapies to treat idiopathic pulmonary fibrosis.     

Isolation of a member of Acinetobacter species involved in atrazine degradation

Contribution of Acinetobacter genus in the degradation of atrazine and its analogs is reported here. An interesting bacterial isolate capable of degrading atrazine as high as 250 ppm was isolated from a soil heavily contaminated with atrazine. The permissible level of atrazine in drinking water is 3 ppb and hence use of a strain capable of atrazine degradation as high as 250 ppm would be of immense help for rapid environmental cleanup. This isolate was found to be capable of best growth at 37 degrees C and at pH inclined towards the alkaline side. It was found that atrazine was utilized as a carbon and not as a nitrogen source. Acinetobacter species was also active on other triazine pesticides, viz., simazine, terbutryn, cyanazine, and prometon. There are very few reports on the degradation of atrazine by any member of this genus and hence this could lead to new degradation pathways and new metabolites.     

Potential of termite gut microbiota for biomethanation of lignocellulosic wastes: current status and future perspectives

Reviews in Environmental Science and Bio/Technology - Lignocellulosic biomass is the most abundant renewable energy resource on earth that can be utilized for biofuel production. However, its...