Enhancement of phospholipid hydrolysis in vasopressin-stimulated BHK-21 and H9c2 cells

The hydrolysis of phospholipids in vasopressin-stimulated baby hamster kidney (BHK)-21 and H9c2 myoblastic cells was investigated. Phosphatidylcholine and phosphatidylethanolamine in these cells were pulse labelled with [³H]glycerol, [³H]myristate, [³H]choline or [³H]ethanolamine, and chased with the non-labelled precursor until linear turnover rates were obtained. When cells labelled with [³H]glycerol or [³H]myristate were stimulated by vasopressin, no significant decrease in the labelling of phosphatidylcholine was detected, but the labelling of phosphatidic acid was elevated. However, the labellings of phosphatidylethanolamine and its hydrolytic product were not affected by vasopressin stimulation. When the cells were pulse labelled with [³H]-choline, vasopressin stimulation caused a decrease in the labelled phosphatidylcholine with a corresponding increase in the labelled choline. The apparent discrepancy between the two types of labelling might be explained by the recycling of labelled phosphatidic acid back into phosphatidylcholine, thus masking the reduction in the labelled phospholipid during vasopressin stimulation. Alternatively, the labelled choline produced by vasopressin stimulation was released into the medium, thus reducing the recycling of label precursor back into the phospholipid and making the decrease in the labelling of phosphatidylcholine readily detectable. Further studies revealed that vasopressin treatment caused an enhancement of phospholipase D activity in these cells. The presence of substrate-specific phospholipase D isoforms in mammalian tissues led us to postulate that the differential stimulation of phospholipid hydrolysis by vasopressin was caused by the enhancement of a phosphatidylcholine-specific phospholipase D in both BHK-21 and the H9c2 cells.Abbreviations BHK-21 cells baby hamster kidney-21 cells     

Genetic map of 16 polymorphic markers forming three linkage groups assigned to rat Chromosome 4

Sixteen polymorphic markers, including markers for eight new loci, forming three linkage groups, were assigned to rat Chromosome (Chr) 4 by linkage analysis of the progeny of an F₂ intercross of Fischer (F344/N) and Lewis (LEW/N) inbred rats. One gene, Igk, was mapped by restriction fragment length polymorphism (RFLP) analysis. One marker for Tcrb was identified by the polymorphic insertion of a repetitive LINE element. The remaining 14 markers contained polymorphic simple sequence repeats (SSRs). Ten were identified in genes (Tgfa, Npy, Prss1, Prss2, Aldr1, Iapp, Prp, Eno2, Cacnlla1, and Il6), one was identified in a sequence related to a gene (Egr4l1), and three were identified in anonymous DNA segments. The SSR markers were highly polymorphic in 16 inbred rat strains. These markers expand the genetic map of the rat and should be useful in future genetic studies of inbred rats.     

Relationship between photochemical reflectance index with multi-angle hyper-spectrum and light use efficiency in urban green-land ecosystems北大核心CSCD

Aims: Light-use efficiency (LUE) is one of critical parameters in the terrestrial ecosystem production studies. Accurate determination of LUE is very important for LUE models to simulate gross primary productivity (GPP) at regional and global scales. We used eddy covariance technique measurement and tower-based, multi-angular spectro-radiometer observations in autumn 2012 to explore the relationship between bidirectional reflectance distribution function (BRDF) corrected photochemical reflectance index (PRI) and LUE in different phenology and environment conditions in urban green-land ecosystems. Methods: Using the eddy covariance technique, we estimated the temporal changes in GPP during the autumn 2012 over Beijing Olympic Forest Park. LUE was calculated as the ratio of GPP to the difference between incoming photosynthetically active radiation (PA R) and PA R reflected from the canopy. Daily PRI values were averaged from the BRDF using semi-empirical kernel driven models. The absolute greenness index (2G-RB) was made by webcam at a constant view zenith and view azimuth angle at solar noon. The logistic function was used to fit the time series of the greenness index. The onset of phonological stages was defined as the point when the curvature reached its maximum value. Important findings: Webcamera-observed greenness index (2G-RB) showed a decreasing trend. There was a highly significant relationship between 2G-RB and air temperature (R2 = 0.60, p < 0.001). This demonstrates that air temperature is the main driving factor to determine the phenology. PRI estimated from multi-angle hyper-spectrum can estimate LUE in urban green-land ecosystems in vigorous photosynthetic period. The correlation was the strongest (R2 = 0.70, p < 0.001) in the peak photosynthetic period. PRI relates better to LUE under high temperature (>15°C) with high vapour pressure deficit (VPD) (>700 Pa) and high PAR (>300 μmol·m-2·s-1). The LUE was up-scaled to landscape/regional scales based on these relationships and phenology. It can also be used for the estimation of GPP of urban green-land with high accuracy.     

Records of Hedotettix and Teredorus in Thailand with the description of three new species (Orthoptera,Tetrigidae)

We are studying the fungi associated with insects in northern Thailand and as a result several rarely collected insect species have been uncovered. The genera Hedotettix with one new species and Teredorus with two new species are reported from Thailand. Hedotettix triangularis Zha & Hyde, sp. n., Teredorus chiangraiensis Zha & Hyde, sp. n. and Teredorus combfemorus Zha & Hyde, sp. n. are introduced, described and photographed and compared with other species. Keys to species of Hedotettix and Teredorus from Thailand are provided.     

Lycium amarum sp. nov. (Solanaceae) from Xizang,supported from morphological characters and phylogenetic analysis

Lycium amarum sp. nov. L. Q. Huang is described based on its general morphology and pollen micromorphology, which were compared with closely related Lycium species. The phylogenetic relationships among the new species and closely related Lycium species belonging to the tribe Lycieae were investigated based on the DNA sequence data of the granule‐bound starch synthase (GBSSI) gene. Morphologically, L. amarum is similar to L. chinense Mill. sharing lanceolate or linear‐oblanceolate leaves, three‐lobed calyx, villous ring slightly above the filament base, and adjacent corolla tube, however, L. amarum may be diagnosed by its prominent tubercles at the base of spines, thinly leathery leaves, and a two‐tine crack on the tip of calyx lobes. According to our results, the new species is close to L. barbarum L., L. chinense, L. dasystemum Pojark, and L. yunnanense Kuang & Lu.     

高粱叶片磷酸烯醇式丙酮酸羧化酶溶液构象状态的紫外差示吸收光谱研究

PEP诱导产生的差光谱在237nm是一强负峰,在252nm附近呈宽负峰。Mg~(2+)产生的差光谱在275nm附近为正的阔峰,在237nm处为一负峰。PEP、Mg~(2+)共同与酶作用的差光谱在263nm附近呈宽的负峰。正效应剂G6P、Gly及GG分别存在条件下PEP羧化酶的差光谱亦各具明显差异,在270nm以下光区内尤其显著。在284nm和291nm为两个负峰,Gly诱导的峰强度大于G6P的,而GG复合效应剂对此两峰的影响表现很大的协同作用。Mal作用于酶的差光谱在246nm处有一负峰。     

Intracellular boron localization and uptake in cell cultures using imaging secondary ion mass spectrometry (ion microscopy) for neutron capture therapy for cancer.

Quantitative ion microscopy of freeze-fractured, freeze-dried cultured cells is a technique for single cell and subcellular elemental analysis. This review describes the technique and its usefulness in determining the uptake and subcellular distribution of the boron from boron neutron capture therapy drugs.