Responses of antioxidant potentials in Dioscorea rotundata Poir. following paclobutrazol drenching

The effect of paclobutrazol (PBZ) treatments on the antioxidant metabolism of white yam (Dioscorea rotundata Poir.) was investigated in the present study. PBZ @ 15 mg l(-1) plant(-1) was given to plants by soil drenching, 30, 60, and 90 days after planting (DAP). The non-enzymatic antioxidant contents like ascorbic acid (AA), reduced glutathione (GSH) and alpha-tocopherol (alpha-toc), activities of antioxidant enzymes like superoxide dismutase (SOD), ascorbate peroxidase (APX), polyphenol oxidase (PPO) and catalase (CAT) were extracted and assayed on 100 DAP from leaf, stem and tubers of both control and PBZ treated plants. It was found that PBZ has a profound effect on the antioxidant metabolism and caused an enhancement in both non-enzymatic and enzymatic antioxidant potentials under treatments in white yam. Our results have good significance, as this increase the innate antioxidant potential of this food crop, which is helpful to satisfy the needs of antioxidants in diet and thereby make it an economically important food crop.     

Calcium chloride effects on salinity-induced oxidative stress, proline metabolism and indole alkaloid accumulation in Catharanthus roseus

Catharanthus roseus (L.) G. Don. plants were grown with NaCl and CaCl2 in order to study the effect of CaCl2 on NaCl-induced oxidative stress in terms of lipid peroxidation (TBARS content), H2O2 content, osmolyte concentration, proline (PRO)-metabolizing enzymes, antioxidant enzyme activities, and indole alkaloid accumulation. The plants were treated with solutions of 80 mM NaCl, 80 mM NaCl with 5 mM CaCl2 and 5 mM CaCl2 alone. Groundwater was used for irrigation of control plants. Plants were uprooted randomly on 90 days after sowing (DAS). NaCl-stressed plants showed increased TBARS, H2O2, glycine betaine (GB) and PRO contents, decreased proline oxidase (PROX) activity, and increased gamma-glutamyl kinase (gamma-GK) activity when compared to control. Addition of CaCl2 to NaCl-stressed plants lowered the PRO concentration by increasing the level of PROX and decreasing the gamma-GK activities. Calcium ions increased the GB contents. CaCl2 appears to confer greater osmoprotection by the additive role with NaCl in GB accumulation. The antioxidant enzymes superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were increased under salinity and further enhanced due to CaCl2 treatment. The NaCl-with-CaCl2-treated C. roseus plants showed an increase in total indole alkaloid content in shoots and roots when compared to NaCl-treated and untreated plants.     

Simulating Epstein-Barr virus infection with C-ImmSim

MOTIVATION: Epstein-Barr virus (EBV) infects greater than 90% of humans benignly for life but can be associated with tumors. It is a uniquely human pathogen that is amenable to quantitative analysis; however, there is no applicable animal model. Computer models may provide a virtual environment to perform experiments not possible in human volunteers. RESULTS: We report the application of a relatively simple stochastic cellular automaton (C-ImmSim) to the modeling of EBV infection. Infected B-cell dynamics in the acute and chronic phases of infection correspond well to clinical data including the establishment of a long term persistent infection (up to 10 years) that is absolutely dependent on access of latently infected B cells to the peripheral pool where they are not subject to immunosurveillance. In the absence of this compartment the infection is cleared. AVAILABILITY: The latest version 6 of C-ImmSim is available under the GNU General Public License and is downloadable from www.iac.cnr.it/~filippo/cimmsim.html     

The effects of reaction conditions on the production of γ-cyclodextrin from tapioca starch by using a novel recombinant engineered CGTase

A novel mutant enzyme namely H43T CGTase can produce up to 39% γ-cyclodextrin (γ-CD) compared to the native enzyme which produces only 10% γ-CD. The effect of the reaction conditions on γ-CD production was studied using this mutant CGTase. The effects of substrate–buffer combination, starch pretreatment and concentration, pH, additives and finally the use of a debranching enzyme improved the γ-CD ratio further. The tapioca–acetate pair gave the highest conversion (16% conversion) among four types of starch and four buffer system combinations. Gelatinized starch was preferred compared to raw tapioca starch in producing a high percentage of γ-CD and conversion rate. Higher pH especially pH 8–9 led to a higher proportion of γ-CD, and was relatively more apparent when the concentration of starch was increased. Forty-six percent γ-CD was produced using 2.5% gelatinized tapioca starch at pH 8. Pullulanase enzyme was found to be useful in reducing the viscosity of tapioca starch paste thus increasing the efficiency of utilization of starch by CGTase by at least 20- to 30-fold. Up to 48% γ-CD can be produced when 4% pullulanase-pretreated tapioca starch was reacted with the CGTase mutant. It was also found that the supplementation of the reaction mixture with glucose, toluene, or cyclododecanone improved the γ-CD yield by 42.2, 46.4, 43.4, and 43.4%, respectively. All the parameters involved have been shown to affect the product specificity of the mutant H43T CGTase transglycosylation mechanism.     

Falling with Style: Bats Perform Complex Aerial Rotations by Adjusting Wing Inertia

The remarkable maneuverability of flying animals results from precise movements of their highly specialized wings. Bats have evolved an impressive capacity to control their flight, in large part due to their ability to modulate wing shape, area, and angle of attack through many independently controlled joints. Bat wings, however, also contain many bones and relatively large muscles, and thus the ratio of bats’ wing mass to their body mass is larger than it is for all other extant flyers. Although the inertia in bat wings would typically be associated with decreased aerial maneuverability, we show that bat maneuvers challenge this notion. We use a model-based tracking algorithm to measure the wing and body kinematics of bats performing complex aerial rotations. Using a minimal model of a bat with only six degrees of kinematic freedom, we show that bats can perform body rolls by selectively retracting one wing during the flapping cycle. We also show that this maneuver does not rely on aerodynamic forces, and furthermore that a fruit fly, with nearly massless wings, would not exhibit this effect. Similar results are shown for a pitching maneuver. Finally, we combine high-resolution kinematics of wing and body movements during landing and falling maneuvers with a 52-degree-of-freedom dynamical model of a bat to show that modulation of wing inertia plays the dominant role in reorienting the bat during landing and falling maneuvers, with minimal contribution from aerodynamic forces. Bats can, therefore, use their wings as multifunctional organs, capable of sophisticated aerodynamic and inertial dynamics not previously observed in other flying animals. This may also have implications for the control of aerial robotic vehicles.     

Effectiveness of Antegrade Access in Bladder Tumors With Inaccessible Urethra

Inaccessible urethra with no retrograde endoscopic access due to multiple/diffuse strictures or multiple urethrocutaneous fistulas with acute urinary retention due to posturethral instrumentation (transurethral resection of bladder tumor [TURBT], or TURBT with transurethral resection of the prostate [TURP]), is a rare entity. Management of such a case with a bladder tumor for TURBT/surveillance cystoscopy poses a great challenge. The authors present 12 cases of bladder tumor with inaccessible urethra, 10 cases due to multiple strictures (post-TURBT and/or TURP), and 2 cases due to urethrocutaneous fistulas (post-TURBT), who presented to our emergency department with acute urinary retention. Emergent suprapubic catheterization was used as a temporary treatment method.Key words: Suprapubic cystostomy, Inaccessible urethra, Bladder tumors, Tract seedlingBladder tumors are the most common neoplasm of the lower urinary tract, comprising 6% of all malignancies in men and 2% of those in women.¹ A majority of patients present with gross painless hematuria, usually as the sole presenting symptom.² Bladder carcinoma is unique among human neoplasms in that many of its etiologic factors are known; the urologist should be aware of the possible occupational exposures to urothelial carcinogens.³ Initial symptoms of urothelial carcinoma of the bladder (UCB) include microhematuria, painless macrohematuria, and/or irritative voiding symptoms, and require further investigation. Carcinoma in situ of the bladder causes irritative lower urinary tract symptoms (LUTS) more often than does papillary UCB. Histopathologic evaluation is necessary to assess stage and grade with sufficient certainty after the appearance of bladder tumors.⁴ Bladder tumors spread by implantation in abdominal wounds, denuded epithelium, resected prostatic fossa, or traumatized urethra⁵; implantation occurs most often with high-grade tumors.     

Photoperiodic growth control in perennial trees

Plants have to cope with changing seasons and adverse environmental conditions. Being sessile, plants have developed elaborate mechanisms for their survival that allow them to sense and adapt to the environment and reproduce successfully. A major adaptive trait for the survival of trees of temperate and boreal forests is the induction of growth cessation in anticipation of winters. In the last few years enormous progress has been made to elucidate the molecular mechanisms underlying SDs induced growth cessation in model perennial tree hybrid aspen (Populus tremula × P. tremuloides). In this review we discuss the molecular mechanism underlying photoperiodic control of growth cessation and adaptive responses.     

Phenothiazine‐Derived Antipsychotic Drugs Inhibit Dynamin and Clathrin‐Mediated Endocytosis

Chlorpromazine is a phenothiazine‐derived antipsychotic drug (APD) that inhibits clathrin‐mediated endocytosis (CME) in cells by an unknown mechanism. We examined whether its action and that of other APDs might be mediated by the GTPase activity of dynamin. Eight of eight phenothiazine‐derived APDs inhibited dynamin I (dynI) in the 2–12 µm range, the most potent being trifluoperazine (IC₅₀ 2.6 ± 0.7 µm ). They also inhibited dynamin II (dynII) at similar concentrations. Typical and atypical APDs not based on the phenothiazine scaffold were 8‐ to 10‐fold less potent (haloperidol and clozapine) or were inactive (droperidol, olanzapine and risperidone). Kinetic analysis showed that phenothiazine‐derived APDs were lipid competitive, while haloperidol was uncompetitive with lipid. Accordingly, phenothiazine‐derived APDs inhibited dynI GTPase activity stimulated by lipids but not by various SH3 domains. All dynamin‐active APDs also inhibited transferrin (Tfn) CME in cells at related potencies. Structure–activity relationships (SAR) revealed dynamin inhibition to be conferred by a substituent group containing a terminal tertiary amino group at the N2 position. Chlorpromazine was previously proposed to target AP‐2 recruitment in the formation of clathrin‐coated vesicles (CCV). However, neither chlorpromazine nor thioridazine affected AP‐2 interaction with amphiphysin or clathrin. Super‐resolution microscopy revealed that chlorpromazine blocks neither clathrin recruitment by AP‐2, nor AP‐2 recruitment, showing that CME inhibition occurs downstream of CCV formation. Overall, potent dynamin inhibition is a shared characteristic of phenothiazine‐derived APDs, but not other typical or atypical APDs, and the data indicate that dynamin is their likely in‐cell target in endocytosis.