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The approach to new drugs through natural products has proved to be the single most successful strategy for the discovery of new drugs, but in recent years its use has been deemphasized by many pharmaceutical companies in favor of approaches based on combinatorial chemistry and genomics, among others. Again with rapid industrialization of the planet and the loss of ethnic culture and customs, some of the information on ethnomedicine will no doubt disappear. An abundance of ethnomedical information on plant uses can be found in scientific literature but has not yet been compiled into a usable form. Collection of ethnomedical information especially in the developing countries remains primarily an academic endeavour of little interest to most industrial groups. This article reviews some of the past successes of the natural products approach and also explores some of the reasons why it has fallen out of favor among major pharmaceutical companies and the challenges in drug discovery from Natural Products especially Higher Plants. In this review we consider the past, present, and future value of employing information from plants used in traditional medical practices (ethnomedicine) for the discovery of new bioactive compounds.

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ᮀ While contradictory reports are available on the yield of dicentric chromosomes (DC) in blood samples stored at different temperature and stimulated to enter into cell cycle, various times gap followed by exposure, limited information is available on the micronucleus (MN) assay. As scoring the micronuclei frequency from the blood lymphocytes of exposed individuals is an alternative to the gold standard DC assay for triage applications, we examined radiation induced MN yield in delayed mitogenic stimulation after irradiation of in vitro. Peripheral blood lymphocytes (PBL) were exposed to low LET ( 60 Co) radiation dose (0.1 to 5Gy) and incubated at 37°C for 2, 6 and 24 hours. The MN frequency obtained in blood samples stimulated 2 hours post-irradiation showed a dose dependent increase and used to construct the dose-response curve. Further, the results also showed that blood samples stimulated twenty four hours of post-irradiation, a significant reduction (p<0.05) in MN frequencies were obtained when compared to that of blood samples stimulated two hours and six hours after post-irradiation (0.5, 1, 3 and 5Gy). The observed result suggests that the prolonged PBL storage without mitogenic stimulation could lead to interphase cell death and a delayed blood sampling could results in underestimation of dose in biological dosimetry.

Measurement of c-H2AX protein changes in the peripheral blood lymphocytes (PBL) of individuals exposed to ionizing radiation is a simple, sensitive, and rapid assay for radiation triage and early marker of dose estimation. The qualitative and quantitative measurements of the protein changes were examined using flow cytometry and microscopy. Whole blood and isolated lymphocytes were exposed in vitro between 0.1 and 5 Gy doses of 60 Co c-radiation at a dose rate of 1 Gy/min. Radiation induced c-H2AX foci frequency (n 5 3) and relative fluorescence intensity (n 5 7) in PBL was measured at 0.5 and 2 hrs postexposure. The observed dose response for c-H2AX foci frequency at both time points, for whole blood and isolated lymphocytes did not show any significant (P > 0.05) differences. However, when compared with c-H2AX foci frequency scored manually (microscopy), the semiautomated analysis (captured images) showed a better correlation (r 2 5 0.918) than that obtained with automated (Metafer) scoring (r 2 5 0.690). It is noteworthy to mention that, the c-H2AX foci frequency quantified using microscopy showed a dose dependent increase up to 2 Gy and the relative fluorescence intensity (RFI) measured with flow cytometry revealed an increase up to 5 Gy in the PBL exposed in vitro. Moreover, a better correlation was observed between the c-H2AX foci frequency obtained by manual scoring and RFI (r 2 5 0.910). Kinetic studies showed that the c-H2AX foci remain more or less unchanged up to 4 hrs and reduces gradually over 48 hrs of postexposure at 378C. Further, inter and intra-laboratory comparisons showed consistency in the scoring of c-H2AX foci frequency by manual and semiautomated scoring. The overall results suggest that measurement of c-H2AX (microscopy and flow cytometry) should be employed within 4 to 6 hrs for a reliable dosimetry either by sharing the work load between the laboratories or investing more manpower; however, triage can be possible even up to 48 hrs of postirradiation. V C 2015 International Society for Advancement of Cytometry

A miniaturized high-gain (MHG) ultra-wideband (UWB) unidirectional monopole antenna with defected ground structure (DGS) is designed for ultra-wideband applications. The MHG antenna is printed on the FR4 substrate material with an overall size of 26.6-mm [Formula: see text] 29.3-mm [Formula: see text] 1.6-mm, which operates over the UWB frequency range and achieves the bandwidth between 3.1[Formula: see text]GHz and 10.6[Formula: see text]GHz. This high-gain unidirectional antenna exhibits a peak gain of 7.20[Formula: see text]dB with an efficiency of 95%. The compact antenna is a simple overlay design of circular and rectangular patches with the partial ground plane exhibiting high gain and better directivity. The overlay patch antenna acts as the radiator for wider bandwidth compared to the fundamental design of patch antenna and is matched to an SMA connector via 50[Formula: see text][Formula: see text] microstrip feed line. These simulated results are presented using HFSS software package. The designed antennas are fabricated and validated by using Agilent Vector Analyzer.

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