Direct somatic embryogenesis from <Emphasis Type="Italic">Coffea arabica</Emphasis> L. and <Emphasis Type="Italic">Coffea canephora</Emphasis> P ex Fr. under the influence of ethylene action inhibitor-silver nitrate

For the first time direct somatic embryogenesis from hypocotyl explants of in vitro regenerated plantlets of C. arabica and C. canephora was achieved on modified MS medium containing 10 – 70 μM silver nitrate supplemented with 1.1 μM N⁶ benzyladenine and 2.85 μM indole-3-acetic acid. A maximum of 144.1±7.3 and 68.7±3.3 embryos per explant were produced at 40 μM silver nitrate in C. canephora and C. arabica respectively. Only yellow friable embryogenic callus obtained from the cut edges of most of leaf explants of both C. arabica and C. canephora at all concentrations of silver nitrate were tried in this experiment. Formation of secondary embryos from stage I primary embryos (small yellow, round, globular embryos) was more (28.23±1.3) at 60 μM silver nitrate in C. canephora, while 40 μM silver nitrate supported more of secondary embryo formation in C. arabica (40.5±1.2). When stage II (green globular round matured embryos) and stage III primary embryos (tubular stage embryos) were used, secondary embryo formation was very small and many of these embryos developed into plantlets and some of them even rooted. By using these protocols within 45 – 60 days it is possible to get secondary embryos from primary embryos and direct somatic embryos from hypocotyls of in vitro plantlets in both these Coffea species.     

Diagnostic considerations in prolymphocytes in pleural fluid: a case report

BACKGROUND: Prolymphocytes are nucleolated cells that are the defining features of the 2 chronic lymphoproliferative disorders, prolymphocytic leukemia (PLL) and chronic lymphocytic leukemia (CLL) with increased prolymphocytes. Prolymphocytes appear relatively unfamiliar in cytopathology practice, and, particularly when present in body fluids, may resemble blasts or adult T-cell leukemia/ lymphoma (ATLL) cells. CASE: A 32-year-old man, referred to us with a diagnosis of acute leukemia, presented with shortness of breath for 2 months and loss of appetite for 3 months. He had enlarged liver and spleen, 6 and 8 cm, respectively, below the costal margin and pleural effusion. The raised total leukocyte count chiefly comprised prolymphocytes that, especially in the pleural fluid, had prominent nucleoli and significant pleomorphism, raising the possibility of blasts or ATLL. CONCLUSION: Prolymphocytes in body fluids can be misinterpreted as blasts or even ATLL cells. Better awareness among cytopathologists about prolymphocytes and the disease states in which they occur, as well as insistence, in a clinical setting of leukemia, on interpreting the pleural fluid in relation to the clinical and laboratory findings, especially those of the peripheral blood and bone marrow, can prevent misdiagnosis. Equally importantly, immunophenotyping must be done in such situations.     

Time-Lapse Microscopy of Streptomyces coelicolor Growth and Sporulation

Bacteria from the genus Streptomyces are among the most complex of all prokaryotes; not only do they grow as a complex mycelium, they also differentiate to form aerial hyphae before developing further to form spore chains. This developmental heterogeneity of streptomycete microcolonies makes studying the dynamic processes that contribute to growth and development a challenging procedure. As a result, in order to study the mechanisms that underpin streptomycete growth, we have developed a system for studying hyphal extension, protein trafficking, and sporulation by time-lapse microscopy. Through the use of time-lapse microscopy we have demonstrated that Streptomyces coelicolor germ tubes undergo a temporary arrest in their growth when in close proximity to sibling extension sites. Following germination, in this system, hyphae extended at a rate of ~20 μm h⁻¹, which was not significantly different from the rate at which the apical ring of the cytokinetic protein FtsZ progressed along extending hyphae through a spiraling movement. Although we were able to generate movies for streptomycete sporulation, we were unable to do so for either the erection of aerial hyphae or the early stages of sporulation. Despite this, it was possible to demonstrate an arrest of aerial hyphal development that we suggest is through the depolymerization of FtsZ-enhanced green fluorescent protein (GFP). Consequently, the imaging system reported here provides a system that allows the dynamic movement of GFP-tagged proteins involved in growth and development of S. coelicolor to be tracked and their role in cytokinesis to be characterized during the streptomycete life cycle.     

Cortical 5-HT1A receptor downregulation by antidepressants in rat brain

Total 5-HT binding sites and 5-HT_1A receptor density was measured in brain regions of rats treated with imipramine (5 mg/kg body wt), desipramine (10 mg/kg body wt) and clomipramine (10 mg/kg body wt), for 40 days, using [³H]5-HT and [³H]8-OH-DPAT, respectively. It was observed that chronic exposure to tricyclic antidepressants (TCAs) results in significant downregulation of total [³H]5-HT binding sites in cortex (42–76%) and hippocampus (35–67%). The 5-HT_1A receptor density was, however, decreased significantly (32–60%) only in cortex with all the three drugs. Interestingly, in hippocampus imipramine treatment increased the 5-HT_1A receptor density (14%). The affinity of [³H]8-OH-DPAT was increased only with imipramine treatment both in cortex and hippocampus. The affinity of [³H]5-HT to 5-HT binding sites in cortex was increased with imipramine treatment and decreased with desipramine and clomipramine treatment. 5-HT sensitive adenylyl cyclase (AC) activity was significantly increased in cortex with imipramine (72%) and clomipramine (17%) treatment, whereas in hippocampus only imipramine treatment significantly increased AC activity (50%). In conclusion, chronic treatment with TCAs results in downregulation of cortical 5-HT_1A receptors along with concomitant increase in 5-HT stimulated AC activity suggesting the involvement of cortical 5-HT_1A receptors in the mechanism of action of TCAs.     

SNARE assembly and disassembly exhibit a pronounced hysteresis.

SNARE proteins are essential for intracellular membrane fusion of eukaryotes. Their assembly into stable four-helix bundles bridges membranes and may provide the energy for initiating membrane fusion. In vitro, assembly of soluble SNARE fragments is accompanied by major structural rearrangements that can be described as a folding reaction. The pathways and the thermodynamics of SNARE protein interactions, however, are not known. Here we report that assembly and dissociation of two distantly related SNARE complexes exhibit a marked hysteresis. The assembled and disassembled native states are separated by a kinetic barrier and cannot equilibrate on biologically relevant timescales. We suggest that the hysteresis is a hallmark of all SNARE complexes and that complex assembly and disassembly follow different pathways that may be independently controlled.     

The role of abscisic acid in the ripening of grapes

Ripening in grapes ( Vitis vinifera L. cv. Thompson seedless) was accompanied by an increase in the levels of sucrose, glucose and fructose and a decrease in the levels of acids. The activity of glucose-6-phosphatase and fructose-l–6-bisphospbatase was lower in sweet grapes as compared to sour ones. Abscisic acid (10⁻⁶ M) stimulated the gluconeogenic process in sour grapes. The levels of some gluconeogenic enzymes were also elevated in its presence. Cyclohexitnide (0.036–1.8 mM) nullified the abscisic acid effect, suggesting that this effect involves de novo protein synthesis. The incorporation of [¹⁴C]-leucine into proteins was enhanced about 80% by abscisic acid, confirming that abscisic acid promoted protein synthesis. Again, cycloheximide blocked the hormone mediated increase in the incorporation of radioactivity into proteins. The results indicate that one of the factors for sourness in certain mature ripe grapes may be that abscisic acid is not available.     

Antifungal activity of Syzygium samarangense leaf extracts against Candida

Candida species are opportunistic human fungal pathogens that cause acute and chronic infections against which only few antifungal agents are available. Here we have elucidated the antifungal effect of Syzygium samarangense leaf extracts (SSLE). Antifungal activity of SSLE was studied against Candida albicans, C. krusei, C. parapsilosis, C. glabrata, C. auris and C. tropicalis. Following experiments were performed: minimum fungicidal concentration (MFC) determination, agar well disc diffusion assays, fungal morphology analysis using scanning electron microscope (SEM), ex vivo fungal survival assays on porcine tongue and skin and in vivo fungal survival assays using Drosophila melanogaster fly model. Results demonstrated MFC of SSLE ranges between 100 and 125 mg ml⁻¹. SEM images showed cell wall degradation of C. albicans when treated with SSLE. Around 75% decrease in C. albicans viability was observed when infected porcine tongue and skin were treated using SSLE. The C. albicans infected D. melanogaster when fed with SSLE showed significant decrease (around 80%) of fungal count than the infected control. Furthermore, agar plate disc diffusion assays demonstrated that the antifungal activity of SSLE could be due to chalcone, which is one of the active constituents in SSLE. Our study demonstrated that SSLE could be used for the topical treatment of Candida infections.     

Genes involved in phosphatidylcholine biosynthesis correlate with nuclear factor-κB in biliary tract cancer patients: Evidence from 1H NMR and computational analyses

Gallbladder cancer (GBC) is an aggressive malignancy of gastrointestinal tract. Due to uncontrolled growth, GBC cells rapidly synthesize biomolecules including lipids. The lipids are integral component of cell membrane with a wide range of cellular functions. In this study, we measured the clinicopathological features in 40 cases of histologically confirmed GBC and 16 cases of chronic cholecystitis (CC). The female to male ratio in the GBC and CC groups were 3.44:1 and 2.2:1, respectively. The GBC patients exhibited well to poorly differentiated tumor. In the CC group, all patients showed cholecystitis with no evidence of dysplasia or malignancy. The majority of GBC and CC patients reported pain. Using ¹H NMR spectroscopy, we observed 4-folds increase in the level of choline containing phospholipids (CCPLs) in the gallbladder of GBC patients as compared to CC patients. Other lipid metabolites such as cholesterol ester, C18-cholesterol and saturated fatty acids were insignificantly changed between GBC and CC patients. Moreover, the level of CCPLs in the GBC patients with BMI <25 kg/m² was significantly higher as compared to CC patients. Further, a significant increase in the CCPLs level was observed in GBC female patients in comparison to CC patients. From the computational analyses, we observed that the genes involved in the biosynthesis of phosphatidylcholine (PtdCho) indirectly interact with the RELA, which encodes the NF-κB p65 subunit. The genes involved in the PtdCho biosynthesis were also correlated with the overall and disease-free survival of cholangiocarcinoma patients. The study opens new window for exploring the diagnostic and therapeutic potential of CCPLs in GBC patients.     

Behavioral response of female Helicoverpa armigera (Hübner) to different plant part extracts of African marigold Tagetes erecta (L.)

The flowering stage of African marigold Tagetes erecta (L.) was the most preferred for oviposition by Helicoverpa armigera (Hübner). The lower sides of leaf margins received more eggs compared to buds, stem tip and flowers. Olfactometer studies revealed that more female moths were attracted towards the flower extracts, followed by leaf, bud and stem tip extracts of African marigold. The thin layer chromatography analysis of these extracts showed a blend of compounds including careen, ocimene, methyl benzoate, phenyl acetaldehyde and phenyl ethanol. Attempts have been made to correlate insect behavior with the presence of these compounds.