Development of Diagnostic Microscopic and Chemical Markers of Some Euphorbia Latexes

The latexes of the three Euphorbia species, namely E. antiquorum L., E. nerifolia L., and E. tirucalli L., are highly valued in the Indian system of medicine as purgatives, in addition to their specific and distinct therapeutic activities. In order to distinguish these latexes and develop their diagnostic microscopic and chemical markers, we performed extensive chemical and microscopic studies. The three latexes differ significantly in their microscopic features by exhibiting characteristic starch grain patterns. Although amoebic structures were found to be characteristic of E. antiquorum, dumb-bell and oval structures are characteristic of E. nerifolia and E. tirucalli, respectively. In addition, these latexes showed bone-shaped structures as a common feature, but these differed considerably in their length （10-60, 30-55, and 50-70 μm in length in E. antiquorum, E. nerifolia, and E. tirucalli, respectively）. The chemical markers nerifoliene and euphol were found to be common to both E. antiquorum and E. nerifolia, whereas euphol is the only marker for E. tirucalli. A reverse-phase high-performance thin-layer chromatographic （HPTLC） method was developed to distinguish these three latexes and to generate their standard fingerprinting patterns. Most significantly, the markers nerifoliene and euphol could be resolved by RP-18 F254s precoated aluminium plates and the latexes have been quantitatively estimated with respect to these markers. The developed microscopic, chemical and HPTLC patterns can be used to distinguish the three latexes.     

Aldo‐keto reductase enzymes detoxify glyphosate and improve herbicide resistance in plants

In recent years, concerns about the use of glyphosate‐resistant crops have increased because of glyphosate residual levels in plants and development of herbicide‐resistant weeds. In spite of identifying glyphosate‐detoxifying genes from microorganisms, the plant mechanism to detoxify glyphosate has not been studied. We characterized an aldo‐keto reductase gene from Pseudomonas (PsAKR1) and rice (OsAKR1) and showed, by docking studies, both PsAKR1 and OsAKR1 can efficiently bind to glyphosate. Silencing AKR1 homologues in rice and Nicotiana benthamiana or mutation of AKR1 in yeast and Arabidopsis showed increased sensitivity to glyphosate. External application of AKR proteins rescued glyphosate‐mediated cucumber seedling growth inhibition. Regeneration of tobacco transgenic lines expressing PsAKR1 or OsAKRI on glyphosate suggests that AKR can be used as selectable marker to develop transgenic crops. PsAKR1‐ or OsAKRI‐expressing tobacco and rice transgenic plants showed improved tolerance to glyphosate with reduced accumulation of shikimic acid without affecting the normal photosynthetic rates. These results suggested that AKR1 when overexpressed detoxifies glyphosate in planta.     

Luminescence analysis of SrGa2Si2O8: RE3+ (RE = Dy,Tm) phosphors

This article reports on the luminescence properties of rare earth (Dy³⁺ and Tm³⁺)ions doped SrGa₂Si₂O₈ phosphor were studied. SrGa₂Si₂O₈phosphors weresynthesizedby employing solid state reaction method.From the measured X‐ray diffraction (XRD) pattern of the samplemonoclinic phase structure has been observed. Thermoluminescenceand Mechanoluminescence properties of the γ‐ray irradiated samples have been studied. Photoluminescence spectra of Dy³⁺ activated SrGa₂Si₂O₈phosphor has been measured with an excitation wavelength at 348 nm,and it shows two emission bands at 483 and 574 nm due to ⁴F_9/2 → ⁶H_15/2 and ⁴F_9/2 → ⁶H_13/2 transitions respectively. Whereas the photoluminescence spectra of Tm³⁺ activated SrGa₂Si₂O₈ phosphor has been measured with an excitation wavelength at 359 nm and it exhibits two emission bands at 454 and 472 nm due to ¹D₂ → ³F₄ and¹G₄ → ³H₆ transitions respectively. In thermoluminescence study, γ‐irradiatedthermoluminescence glow curve of SrGa₂Si₂O₈:Dy³⁺ phosphor shows two well defined peaks at 293 °C (peak1)and 170 °C (peak2) whereas thermoluminescence glow curve of SrGa₂Si₂O₈:Tm³⁺ phosphor shows peaks at 292 °C (peak1) and 184 °C (peak2) indicating that two sets of traps are being activated within the particular temperature range and the trapping parameters associated with the prominent glow peaks of SrGa₂Si₂O₈:Dy³⁺ and SrGa₂Si₂O₈:Tm³⁺ are calculated using Chen's peak shape and initial rise method.From the Mechanoluminescence study, only one glow peak has been observed. Copyright © 2016 John Wiley & Sons, Ltd.     

Photosynthesis Parameters in Two Cultivars of Mulberry Differing in Salt Tolerance

Three-month-old mulberry (Morus alba L.) cultivars (salt tolerant cv. S1 and salt sensitive cv. ATP) were subjected to different concentrations of NaCl for 12 d. Leaf area, dry mass accumulation, total chlorophyll (Chl) content, net CO₂ assimilation rate (P _N), stomatal conductance (g _s), and transpiration rate (E) declined, and intercellular CO₂ concentration (C _i) increased. The changes in these parameters were dependent on stress severity and duration, and differed between the two cultivars. The tolerant cultivar showed a lesser reduction in P _N and g _s coupled with a better C _i and water use efficiency (WUE) than the sensitive cultivar. This revised version was published online in June 2006 with corrections to the Cover Date.     

Perturbation of wild-type lamin A metabolism results in a progeroid phenotype

Mutations in the lamin A/C gene cause the rare genetic disorder Hutchinson-Gilford progeria syndrome (HGPS). The prevalent mutation results in the production of a mutant lamin A protein with an internal 50 amino acid deletion which causes a cellular aging phenotype characterized by growth defects, limited replicative lifespan, and nuclear membrane abnormalities. However, the relevance of these findings to normal human aging is unclear. In this study, we demonstrate that increased levels of wild-type lamin A in normal human cells result in decreased replicative lifespan and nuclear membrane abnormalities that lead to apoptotic cell death and senescence in a manner that is strongly reminiscent of the phenotype shown by HGPS cells. In contrast to the accelerated aging defects observed in HGPS cells, the progeroid phenotype resulting from increased expression of wild-type lamin A can be rescued by overexpression of ZMPSTE24, the metalloproteinase responsible for the removal of the farnesylated carboxyl terminal region of lamin A. Furthermore, farnesyltransferase inhibitors also serve to reverse the progeroid phenotype resulting from increased lamin A expression. Significantly, cells expressing elevated levels of lamin A display abnormal lamin A localization and similar alterations in the nuclear distribution of lamin A are also observed in cells from old-age individuals. These data demonstrate that the metabolism of wild-type lamin A is delicately poised and even in the absence of disease-linked mutations small perturbations in this system are sufficient to cause prominent nuclear defects and result in a progeroid phenotype.     

In vitro capsaicin production by immobilized cells and placental tissues of Capsicum annuum L. grown in liquid medium

Capsaicin, from green pepper fruits is used in formulated foods and in pharmaceuticals. Cell cultures of Capsicum annuum L. were obtained from seedlings on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin. In vitro-grown cells and placental tissues from fruits were immobilized in calcium alginate. Immobilized cells and placental tissues produced capsaicin which leached out into the medium. Immobilized placental tissue exhibited greater potentiality for capsaicin synthesis than immobilized cells. Production reached a level of 1345 μg capsaicin g⁻¹ of immobilized placenta on the 14th day of culture. Production of capsaicin, on replenished nutrient medium in immobilized placenta was 2400 μg on the 30th day. Ferulic acid fed to immobilized placenta at 2.5 mM level increased capsaicin production by 2-fold by the 5th day of the culture period. Of the elicitors used, curdlan was effective on capsaicin production in immobilized cells. Extracts of Aspergillius niger and Rhizopus oligosporus stimulated capsaicin production in immobilized placental tissues.     

Synthesis and luminescence properties of Ca3Ga2Si3O12:RE3+ (RE = Eu/Tb) powder phosphors

Rare earth ions (Eu³⁺ or Tb³⁺)‐activated Ca₃ Ga₂ Si₃O₁₂ (CaGaSi) phosphors were synthesized by using a sol–gel method. Photoluminescence spectra of Eu³⁺:CaGaSi phosphors exhibited five emission bands at 578, 592, 612, 652 and 701 nm, which were assigned to the transitions (⁵D₀ → ⁷F₀, ⁷F_1, ⁷F₂, ⁷F₃ and ⁷F₄), respectively, with an excitation wavelength of λ_exci = 392 nm. Among these, the transition ⁵D₀ → ⁷F₂ (612 nm) displayed bright red emission. In the case of Tb³⁺:CaGaSi phosphors, four emission bands were observed at 488 (⁵D₄ → ⁷F₆), 543 (⁵D₄ → ⁷F₅), 584 (⁵D₄ → ⁷F₄) and 614 nm (⁵D₄ → ⁷F₃) from the measurement of PL spectra with λ_exci = 376 nm. Among these, the transition ⁵D₄ → ⁷F₅ at 543 nm displayed bright green emission. The structure and morphology of the phosphors were studied from the measurements of X‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy‐dispersive X‐ray analysis (EDAX) results. Copyright © 2011 John Wiley & Sons, Ltd.     

Role of inflammasomes and their regulators in prostate cancer initiation, progression and metastasis

Prostate cancer is one of the main cancers that affect men, especially older men. Though there has been considerable progress in understanding the progression of prostate cancer, the drivers of its development need to be studied more comprehensively. The emergence of resistant forms has also increased the clinical challenges involved in the treatment of prostate cancer. Recent evidence has suggested that inflammation might play an important role at various stages of cancer development. This review focuses on inflammasome research that is relevant to prostate cancer and indicates future avenues of study into its effective prevention and treatment through inflammasome regulation. With regard to prostate cancer, such research is still in its early stages. Further study is certainly necessary to gain a broader understanding of prostate cancer development and to create successful therapy solutions.     

Electron microscopical studies and restriction analysis ofHelicoverpa armigera nucleo polyhedrosis virus

Nuclear polyhedrosis virus ofHelicoverpa armigera (HaNPV) from Madurai (south India) was isolated, purified and subjected to electron microscopical studies. The results indicate that the isolate is a multi embedded form of NPV. Further, STEM observations on polyhedra and polyhedral envelope of the HaMNPV are presented. The restriction pattern and genome size of HaMNPV Madurai isolate are compared with HaNPV isolates reported earlier. A dendrogram is presented to show the relatedness among the isolates.     

Alterations in Photosystem II Organization by Cobalt Treatment in the Cyanobacterium Spirulina piatensis

The presence of low concentrations of cobalt ions (200 μMCoCl₂) retarded the growth of the cyanobacterium Spirulina platensis. However, cells grown in the presence of CoCl₂ exhibited an enhancement in the levels of phycocyanin and carotenoids, while showed a decrease in the content of chlorophyll a, when compared to the untreated control cells. Thylakoid membranes isolated from CoCl₂ treated cells demonstrated enhanced rates of both photosystem II (H₂O → pBQ) and photosystem I (DCPIPH₂ → MV) mediated electorn transport activities. The stimulation in the rates of photosynthetic electron transport activities in the CoCl ₂ grown cells are attributed to the alterations occurring in the thylakoid membrane organization, as the thylakoids from CoCl₂ grown cells possessed more membrane fluidity. The decrease in the chlorophyll a content may have occurred due to modifications in the chlorophyll a complexes in this cynaobacterium. The enhancement in the phycocyanin levels in the CoCl₂ grown cells appears to be because of the stimulated induction of heme oxygenase. Thus, the cobalt ion treatment appears to be useful in studying the thylakoid membrane and antennae organizations in cyanobacteria.