alpha-Tomatine, the major saponin in tomato, induces programmed cell death mediated by reactive oxygen species in the fungal pathogen Fusarium oxysporum

The tomato saponin alpha-tomatine has been proposed to kill sensitive cells by binding to cell membranes followed by leakage of cell components. However, details of the modes of action of the compound on fungal cells are poorly understood. In the present study, mechanisms involved in alpha-tomatine-induced cell death of fungi were examined using a filamentous pathogenic fungus Fusarium oxysporum. alpha-Tomatine-induced cell death of F. oxysporum (TICDF) occurred only under aerobic conditions and was blocked by the mitochondrial F(0)F(1)-ATPase inhibitor oligomycin, the caspase inhibitor D-VAD-fmk, and protein synthesis inhibitor cycloheximide. Fungal cells exposed to alpha-tomatine showed TUNEL-positive nuclei, depolarization of transmembrane potential of mitochondria, and reactive oxygen species (ROS) accumulation. These results suggest that TICDF occurs through a programmed cell death process in which mitochondria play a pivotal role. Pharmacological studies using inhibitors suggest that alpha-tomatine activates phosphotyrosine kinase and monomeric G-protein signaling pathways leading to Ca(2+) elevation and ROS burst in F. oxysporum cells.     

A new ecdysteroid, 2-deoxy-5beta,20-dihydroxyecdysone from the fruits of Diploclisia glaucescens

Chemical investigation of ethyl acetate extract of the fruits of Diploclisia glaucescens of the family Menispermaceae furnished a new ecdysteroid 2-deoxy-5beta,20-dihydroxyecdysone, together with 20-hydroxyecdysone, 3-deoxy-1beta,20-dihydroxyecdysone, 2-deoxy-20-hydroxyecdysone, 24-ethyl-20-hydroxyecdysone (makisterone C). Latter two ecdysteroids are reported first time from the family Menispermaceae.     

The poetics of babytalk

Caretaker-infant attachment is a complex but well-recognized adaptation in humans. An early instance of (or precursor to) attachment behavior is the dyadic interaction between adults and infants of 6 to 24 weeks, commonly called "babytalk." Detailed analysis of 1 minute of spontaneous babytalk with an 8-week infant shows that the poetic texture of the mother’s speech—specifically its use of metrics, phonetics, and foregrounding—helps to shape and direct the baby’s attention, as it also coordinates the partners’ emotional communication. We hypothesize that the ability to respond to poetic features of language is present as early as the first few weeks of life and that this ability attunes cognitive and affective capacities in ways that provide a foundation for the skills at work in later aesthetic production and response. By linking developmental social processes with formal cognitive aspects of art, we challenge predominant views in evolutionary psychology that literary art is a superfluous byproduct of adaptive evolutionary mechanisms or primarily an ornament created by sexual selection. David S. Miall is Professor of English at the University of Alberta in Canada. He is the author of essays on British Romantic writers, empirical studies of readers’ responses to literature, hypertext and literary computing. Ellen Dissanayake is Visiting Scholar at the Walter Chapin Simpson Center for the Humanities, University of Washington. Her most recent book is Art and Intimacy: How the Arts Began (2000).     

Enantiomeric Separations of Ruthenium (II) Polypyridyl Complexes Using HPLC With Cyclofructan Chiral Stationary Phases

The enantiomeric separation of 21 ruthenium (II) polypyridyl complexes was achieved with a novel class of cyclofructan‐based chiral stationary phases (CSPs) in the polar organic mode. Aromatic derivatives on the chiral selectors proved to be essential for enantioselectivity. The R‐napthylethyl carbamate functionalized cyclofructan 6 (LARIHC CF6‐RN) column proved to be the most effective overall, while the dimethylphenyl carbamate cyclofructan 7 (LARIHC CF7‐DMP) showed complementary selectivity. A combination of acid and base additives was necessary for optimal separations. The retention factor vs. acetonitrile/methanol ratio plot showed a U‐shaped retention curve, indicating that different interactions take place at different polar organic solvent compositions. The separation results indicated that π–π interactions, steric effects, and hydrogen bonding contribute to the enantiomeric separation of ruthenium (II) polypyridyl complexes with cyclofructan chiral stationary phases in the polar organic mode. Chirality 27:64–70, 2015. © 2014 Wiley Periodicals, Inc.     

A Sri Lankan child with 49,XXXXY syndrome

Pentasomy 49,XXXXY is a rare sex chromosome disorder usually presenting with ambigous genitalia, facial dysmorphism, mental retardation and a combination of cardiac, skeletal and other malformations. The incidence of the condition is estimated to be 1 in 85,000 male births. Previously, this condition was identified as a Klinefelter variant. The condition is suspected in a patient, by a combination of characteristic clinical findings, and the diagnosis is confirmed by chromosome culture and karyotyping. In the case we report here, the main presentation of ambiguous genitalia led to a suspicion of a sex chromosome aneuploidy which was subsequently confirmed by chromosomal analysis.     

<Emphasis Type="Italic">Mayaca fluviatilis</Emphasis> Aubl.: an ornamental aquatic with invasive potential in Sri Lanka

The ornamental aquatic plant industry in Sri Lanka has grown substantially during the last decade and there is a renewed demand for several exotic species. Mayaca fluviatilis, a submerged plant used in aquaria, is not recorded as a naturally occurring plant in Sri Lanka. However, recent studies recorded it in the wet zone of Sri Lanka and certain countries have recognized it as a problematic plant. The knowledge of the mode of propagation of invasive species is vital in the management of biological invasions. Therefore, the present study was conducted to investigate the propagation ability of vegetative parts of M. fluviatilis. A field survey was conducted in the wet zone of Sri Lanka, and populations of M. fluviatilis were monitored between 2006 and 2009. The propagation ability of different maturity stages of stem cuttings (terminal, middle and basal) were investigated, and terminal stem cuttings with five different lengths (2, 4, 6, 8 and 10 cm) were used to investigate the propagation ability of fragmented vegetative parts. Terminal shoots showed the highest survival rates and significantly high (P < 0.05) shoot and root lengths compared to middle and basal parts of the stem cuttings. In the other experiment with terminal stem cuttings with different lengths, all the stem fragments were capable of developing into a new plant. Increasing lengths of fragments was significantly related to the number of roots. Nevertheless, as even the 2-cm fragment was capable of developing into a new plant, removal of even the smallest fragments is necessary to control this plant. Submerged plants can spread easily through fragmentation and manual removal will likely increase its spread. Nevertheless, it is considered as effective for small infestations. Therefore, repeated removal of plant parts can be suggested as an ecologically sound management approach to prevent further spread of M. fluviatilis since it is in the early stage of establishment.     

Modeling of Pb(II) adsorption by a fixed-bed column

Removal of Pb(II) from an aqueous environment using biosorbents is a cost-effective and environmentally benign method. The biosorption process, however, is little understood for biosorbents prepared from plant materials. In this study, the biosorption process was investigated by evaluating four adsorption models. A fixed-bed column was prepared using a biosorbent prepared from the aquatic plant Hydrilla verticillata. The effect of bed height and flow rate on the biosorption process was investigated. The objective of the study was to determine the ability of H. verticillata to biosorb Pb(II) from an aqueous environment and to understand the process, through modeling, to provide a basis to develop a practical biosorbent column. Experimental breakthrough curves for biosorption of 50 mg L^?1 aqueous Pb(II) using a fixed-bed column with 1.00 cm inner diameter were fitted to the Thomas, Adams-Bohart, Belter, and bed depth service time (BDST) models to investigate the behavior of each model according to the adsorption system and thus understand the adsorption mechanism. Model parameters were evaluated using linear and nonlinear regression methods. The biosorbent removed 65% (82.39 mg g^?1 of biosorbent) of Pb(II) from an aqueous solution of Pb(NO₃)₂ at a flow rate of 5.0 ml min^?1 in a 10 cm column. Na₂CO₃ was used to recover the adsorbed Pb(II) ions as PbCO₃ from the biosorbent. The Pb(II) was completely desorbed at a bed height of 10.0 cm and a flow rate of 5.0 ml min^?1. Fourier transform infrared (FT-IR) analysis of the native biosorbent and Pb(II)-loaded biosorbent indicated that the hydroxyl groups and carboxylic acid groups were involved in the metal bonding process. The FT-IR spectrum of Pb(II)-desorbed biosorbent showed an intermediate peak shift, indicating that Pb(II) ions were replaced by Na⁺ ions through an ion-exchange process. Of the four models tested, the Thomas and BDST models showed good agreement with experimental data. The calculated bed sorption capacity N₀ and rate constant k_a were 31.7 g L^?1 and 13.6 × 10^?4 L mg^?1 min^?1 for the C_t/C₀ value of 0.02. The BDST model can be used to estimate the column parameters to design a large-scale column.     

Optimizing amniotic membrane tissue banking protocols for ophthalmic use

Amniotic membrane (AM) due to its anti-inflammatory, anti-scarring and anti-angiogenic properties is used as corneal and wound grafts. When developing AM tissue banks, cell viability, membrane morphology and genomic stability should be preserved following cryopreservation. To analyze the changes rendered to the AM during the process of cryopreservation by comparing different combinations of standard cryopreservation media; fetal bovine serum (FBS), dimethyl sulfoxide (DMSO), Dulbecco’s modified eagle’s medium (DMEM) and glycerol at ?80 °C and at ?196 °C for a period of 6 weeks and at 4 °C in 70 % alcohol for 6 weeks. Following informed consent, placentae of healthy term pregnancies delivered by elective Cesarean section were collected and AM separated into 5 × 5 cm size sections and under sterile conditions stored in 9:1 DMSO:FBS and 1:1 DMEM:Glycerol at ?196 and ?80 °C for 6 weeks. Similar sections were also stored at 4 °C in 70 % alcohol for 6 weeks. After storage periods following were assessed; AM epithelial cell viability by trypan blue vital stain, epithelial cell proliferation capacity by cell doubling time, membrane morphology by haematoxylin and eosin (H&E) stain and genomic stability by conventional G-banded karyotyping. Human amniotic epithelial cells were cultured in DMEM and 10 % FBS in humidified atmosphere of 5 % carbon dioxide at 37 °C and were characterized using RT-PCR for Octamer-binding protein 4 (Oct-4) and glucose-6-phosphate dehydrogenase (G6PD) genes. All the above parameters were also assessed in fresh AM. AM obtained from 4 term placentae. Mean cell count and mean cell doubling times in days respectively; for fresh AM 3.8 × 10⁶; 1.59, after 6 weeks in DMSO:FBS at ?196 °C 3.0 × 10⁶; 2.38 and at ?80 °C 2.1 × 10⁶; 1.60, in DMEM:Glycerol at ?196 °C 3.6 × 10⁶; 2.33 at ?80 °C 23 × 10⁶; 1.66 and at 4 °C 3.3 × 10⁶; 2.14. Histology analysis of the fresh AM showed an intact epithelial monolayer, thick basement membrane (BM) and avascular stromal matrix. Amniotic membranes stored at ?196 °C showed morphology similar to fresh AM in both preservation media and AM stored at ?80 °C showed disruption of the stromal matrix. At 4 °C the epithelial monolayer showed flattening. Fresh AM karyotype was 46XX. Analyzable spreads for karyotype were not obtained from stored AMs. Human amniotic epithelial cells were positive for both Oct-4 and G6PD genes. AM is best preserved at ?196 °C either in 1:9 DMSO:FBS or 1:1 DMEM:Glycerol. In both conditions cell viability and membrane integrity were shown to be preserved up to 6 weeks. Since analyzable chromosome spreads from cell cultures were not obtained, genomic stability could not be assessed.