Current status and needs for life cycle assessment development in Asian/Pacific Regions

Conclusion  In conclusion, LCA that is conducted and used appropriately is an indispensable tool to assist decision-makers in making an informed decision about the environmental impacts of their activities, products or services. A global effort towards LCA use should be encouraged and countries in the Asian/Pacific Regions should not be left out. LCA-related activities reported in the symposium were described     

Impact of dengue virus (serotype DENV-2) infection on liver of BALB/c mice: A histopathological analysis

In this research, we characterized the histopathological impact of dengue virus (serotype DENV-2) infection in livers of BALB/c mice. The mice were infected with different doses of DENV-2 via intraperitoneal injection and liver tissues were processed for histological analyses and variation was documented. In the BALB/c mouse model, typical liver tissues showed regular hepatocyte architecture, with normal endothelial cells surrounding sinusoid capillary. Based on histopathological observations, the liver sections of BALB/c mice infected by DENV-2 exhibited a loss of cell integrity, with a widening of the sinusoidal spaces. There were marked increases in the infiltration of mononuclear cells. The areas of hemorrhage and micro- and macrovesicular steatosis were noted. Necrosis and apoptosis were abundantly present. The hallmark of viral infection, i.e., cytopathic effects, included intracellular edema and vacuole formation, cumulatively led to sinusoidal and lobular collapse in the liver. The histopathological studies on autopsy specimens of fatal human DENV cases are important to shed light on tissue damage for preventive and treatment modalities, in order to manage future DENV infections. In this framework, the method present here on BALB/c mouse model may be used to study not only the effects of infections by other DENV serotypes, but also to investigate the effects of novel drugs, such as recently developed nano-formulations, and the relative recovery ability with intact immune functions of host.     

Ceramicines B–D,new antiplasmodial limonoids from Chisocheton ceramicus

Three new limonoids, ceramicines B–D (1–3), have been isolated from the bark of Chisocheton ceramicus. Structures and stereochemistry of 1–3 were fully elucidated and characterized by 2D NMR analysis. Ceramicines exhibited a moderate antiplasmodial activity.     

In situ CO2 gas-exchange in fruits of a tropical tree,Durio zibethinus Murray

We examined the in situ CO₂ gas-exchange of fruits of a tropical tree, Durio zibethinus Murray, growing in an experimental field station of the Universiti Pertanian Malaysia. Day and night dark respiration rates were exponentially related to air temperature. The temperature dependent dark respiration rate showed a clockwise loop as time progressed from morning to night, and the rate was higher in the daytime than at night. The gross photosynthetic rate was estimated by summing the rates of daytime dark respiration and net photosynthesis. Photosynthetic CO₂ refixation, which is defined as the ratio of gross photosynthetic rate to dark respiration rate in the daytime, ranged between 15 and 45%. The photosynthetic CO₂ refixation increased rapidly as the temperature increased in the lower range of air temperature T _c (T _c <28.5 °C), while it decreased gradually as the temperature increased in the higher range (T _c 28.5 °C). Light dependence of photosynthetic CO₂ refixation was approximated by a hyperbolic formula, where light saturation was achieved at 100 mol m^–2 s^–1 and the asymptotic CO₂ refixation was determined to be 37.4%. The estimated gross photosynthesis and dark respiration per day were 1.15 and 4.90 g CO₂ fruit^–1, respectively. Thus the CO₂ refixation reduced the respiration loss per day by 23%. The effect of fruit size on night respiration rate satisfied a power function, where the exponent was larger than unity.     

Somatic embryogenesis of mangosteen

Young red leaf segments from 1 to 3?year-old seedlings of mangosteen (Garcinia mangostana L.) were incubated on different media, consisting of either B5 or Murashige and Skoog (MS) basal media and supplemented with several plant growth regulator at different levels, including 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin or 2,4-D and 6-benzyladenine (BA) or thidiazuron (TDZ) and BA. The highest percentage of globular structures (36.0?%) was obtained using MS medium with a combination of TDZ and BA, each at a concentration of 0.7?mg?l^?1. Histological observation of sections of globular structures showed accumulation of dense meristematic cells, a common characteristic of globular formation during somatic embryogenesis. Molecular analysis detected the gene somatic embryogenesis receptor-like kinase 1 (SERK1). This gene sequence showed a high similarity (73.0?C87.0?%) to previously reported plant SERK1.     

Enyne- and enediyne-γ-lactones from the bark of Meiogyne cylindrocarpa

The chemical investigation of the EtOAc extract of the bark of Meiogyne cylindrocarpa led to the isolation of two enyne- and five enediyne-γ-lactones, sapranthins A–G (1–7), of which six were new. They were identified by mass spectrometry, extensive one- and two-dimensional NMR spectroscopy and through comparison with data reported in the literature. Sapranthins B, C and E (2, 3 and 5, respectively) showed a weak cytotoxic activity on L1210 with IC₅₀ values comprised between 8.1 and 18.0 μM.     

The ‘Checkmate’ for Iron Between Human Host and Invading Bacteria: Chess Game Analogy

Iron is an essential nutrient for all living organisms with critical roles in many biological processes. The mammalian host maintains the iron requirements by dietary intake, while the invading pathogenic bacteria compete with the host to obtain those absorbed irons. In order to limit the iron uptake by the bacteria, the human host employs numerous iron binding proteins and withholding defense mechanisms that capture iron from the microbial invaders. To counteract, the bacteria cope with the iron limitation imposed by the host by expressing various iron acquisition systems, allowing them to achieve effective iron homeostasis. The armamentarium used by the human host and invading bacteria, leads to the dilemma of who wins the ultimate war for iron.     

Somatic embryogenesis and metabolic differences between embryogenic and non-embryogenic structures in mangosteen

Somatic embryogenesis in mangosteen (Garcinia mangstana L.) was investigated using seed and leaf segments cultured on Murashige and Skoog medium with treatments of 6-benzyladenine (BA) [2.0, 3.0, 4.0 µM] and 2,4-diclorophenoxyacetic acid (2,4-D) [4.5, 9.0, 13.5 µM]. There were four types of structures (globular, nodular compact, friable and spongy) formed. Two treatments resulted in embryogenic characteristics from seed cultures; the highest percentage 46.67?% of globular structure (resembling somatic embryos) grown on 3.0 µM BA and 80?% of nodular compact structures on 4.0 µM BA?+?13.5 µM 2,4-D. For the leaf culture, highest percentage, 93.33?% produced nodular compact structures on 2.0 µM BA?+?4.5 µM 2,4-D. Histological analysis showed that the globular structure has well-defined protoderm and separated from the original explant. Nodular compact structure also showed the presence of densely cytoplasmic meristematic cells with a high nucleoplasmic ratio. These characteristics observed in globular and nodular compact structure indicates somatic embryo formation. The globular structures which were converted into shoots and roots (60.00?%) showed atypical somatic embryogenesis in mangosteen. Metabolite fingerprinting was carried out using gas chromatography–mass spectrometry. Amino acids, carbohydrates, organic acids and fatty acids were found in both the embryogenic structures and non-embryogenic structures tested. Multivariate discriminant analyses of the metabolic data revealed significant metabolites (P?≤?0.05) for both types of structures. Principle component analysis suggested that amino acids and carbohydrates were the major compounds distinguishing embryogenic and non-embryogenic structures. Ornithine and mannose were present at significant level in embryogenic structures as compared to non-embryogenic ones while fructose was significantly higher in non-embryogenic structures.     

Resistance factors in pepper inhibit larval development of thrips (Frankliniella occidentalis)

The western flower thrips [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)] is a major pest in pepper cultivation. Therefore, host plant resistance to thrips is a desirable trait. The objectives of this study were to determine the effect of resistance on the development of thrips and to identify metabolite compounds related to the resistance. Three highly resistant, three medium resistant, and three susceptible pepper accessions were used in this study. Adult and pre‐adult survival, developmental time, and oviposition rate were assessed. Gas chromatography‐mass spectrometry was used to identify compounds that correlate with the level of resistance to thrips. Our results show that resistance of pepper accessions has a significant effect on oviposition rate and larval mortality. Seven compounds were identified that correlate with resistance to thrips and six compounds were identified that correlate with susceptibility to thrips. Some of these compounds, such as tocopherols, were previously shown to have an effect on insects in general. Also, some specific secondary metabolites (alkanes) seem to be more abundant in susceptible accessions and were induced by thrips infestation.