Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

Peer facilitated writing groups: a programmatic approach to doctoral student writing

Very few empirical studies have investigated programmes in which doctoral students act as peer facilitators in faculty writing groups. We report on the development of a centrally delivered doctoral student writing programme in which twenty student participants were mentored and provided with the resources to initiate their own faculty-based doctoral writing groups. ‘Legitimate peripheral participation’ was used as a conceptual lens to interpret the data collected during the establishment and evaluation of the programme. All student participants in the preparatory training course, which was developed in consultation with postgraduate students and research supervisors, went on to become doctoral writing peer facilitators of peer writing groups. Insights from seven of these showed how a well-structured and supportive programme harnessed the benefits of peer learning by bringing personal rewards to participants and building institutional capacity around doctoral research writing literacies.     

Three dimensional couette flow and heat transfer through a porous medium with variable permeability

This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional. The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs.     

Erratum to: Effect of Current Electricity Simulation Supported Learning on the Conceptual Understanding of Elementary and Secondary Teachers

This study examined the impact of computer simulation and supported science learning on a teacher’s understanding and conceptual knowledge of current electricity. Pre/Post tests were used to measure the teachers’ concept attainment. Overall, there was a significant and large knowledge difference effect from Pre to Post test. Two interesting interactions were observed during the data analysis. The first was the difference between Elementary and Secondary teachers. Both groups had significant gains, with large effect sizes, but the Elementary teachers (Pre-Mean = 3.70, Post-Mean = 7.51) started lower and ended higher exhibiting a significantly larger gain than the Secondary teachers (Pre-Mean = 4.96, Post-Mean = 6.71). The second interaction was the impact of gender. Both groups showed significant gains, with large effect sizes, but females (Pre-Mean = 3.90, Post-Mean = 7.21) gained significantly more than males (Pre-Mean = 5.13, Post-Mean = 7.01). These results confirm that computer simulation supported science learning can have a positive effect on concept attainment in teachers.     

An Overview of Modern Technologies Applications in Indian Libraries (Brief Communication)

India is one of the oldest civilizations with a kaleidoscopic variety and rich cultural heritage. It has achieved multi-faccted socio-economic progress during the last 47 years of its independence. This article reports on a survey of the usage of modern technologies (e.g. photocopiers, microfilming, computers, facsimile transmission, audio-visual, online searching and CD-ROMs) in Indian libraries. These libraries include university, engineering, scientific, medical, government and public libraries. The study used a questionnaire, personal visits to many libraries and interviews. The paper examines the impact of modern technologies on these libraries. It concludes with a summary of the problems faced by the librarians in adopting the modern technologies and suggests measures for implementation of modern technologies.     

External quality assessment for the RIA of thyroid related hormones: Second phase

An external quality assessment was conducted to assess the performance of various laboratories for RIA of thhyroid related hormones in two phases. In the first phase thirty five laboratories participated. At the end of first phase a meeting cum workshop was organised to discuss the results of first phase, difficultires faced by the participants and pinpoint the short oming. A second phase was then initiated with an objective of improvement in the performance, if any, where twelve samples from four pools were distributed to twenty four laboratories who participated for the second phase. The overall return of the results increased significantly from 71.8% (1586/2208) for the first phase to 92.4% (732/792) for the second phase. The inter laboratory %CV for T₃, T₄ and TSH were lower during the second phase (30.6%, 19.0% and 31.6% respectively) as compared to those observed during first phase (36.3%, 22.7% and 52.8% respectively). Similarly, there was an improvement in reproducibility of ALTM as %CV for T₃, T₄ and TSH decreased from 6.0%, 9.8% and 13.4% respectively to 4.5%, 4.6% and 8.5% respectively. The individual performances of the participating laboratories viz. bias, variability of bias and imprecision also showed a trend towards improvement as percent laboratories having desirable or acceptable results for T₃, T₄ and TSH increased from 10.7%, 60.7% and 0.0% respectively to 20.8%, 66.7% and 22.2% respectively. External quality assessment thus appears to be beneficial in assessing the performane of a laboratory in comfparison with other laboratories and indeed helps in improving the performance.     

A Narrative Review of Potential Future Antidiabetic Drugs: Should We Expect More?

Prevalence of diabetes mellitus, a chronic metabolic disease characterized by hyperglycemia, is growing worldwide. The majority of the cases belong to type 2 diabetes mellitus (T2DM). Globally, India ranks second in terms of diabetes prevalence among adults. Currently available classes of therapeutic agents are used alone or in combinations but seldom achieve treatment targets. Diverse pathophysiology and the need of therapeutic agents with more favourable pharmacokinetic-pharmacodynamics profile make newer drug discoveries in the field of T2DM essential. A large number of molecules, some with novel mechanisms, are in pipeline. The essence of this review is to track and discuss these potential agents, based on their developmental stages, especially those in phase 3 or phase 2. Unique molecules are being developed for existing drug classes like insulins, DPP-4 inhibitors, GLP-1 analogues; and under newer classes like dual/pan PPAR agonists, dual SGLT1/SGLT2 inhibitors, glimins, anti-inflammatory agents, glucokinase activators, G-protein coupled receptor agonists, hybrid peptide agonists, apical sodium-dependent bile acid transporter (ASBT) inhibitors, glucagon receptor antagonists etc. The heterogeneous clinical presentation and therapeutic outcomes in phenotypically similar patients is a clue to think beyond the standard treatment strategy.