Genomic analysis of Cobetia sp. D5 reveals its role in marine sulfur cycling.

Dimethylsulfoniopropionate (DMSP) is one of the most abundant sulfur-containing organic compounds on the earth, which is an important carbon and sulfur source and plays an important role in the global sulfur cycle. Marine microorganisms are an important group involved in DMSP metabolism. The strain Cobetia sp. D5 was isolated from seawater samples in the Yellow Sea area of Qingdao during an algal bloom. There is still limited knowledge on the capacity of DMSP utilization of Cobetia bacteria. The study reports the whole genome sequence of Cobetia sp. D5 to understand its DMSP metabolism pathway. The genome of Cobetia sp. D5 consists of a circular chromosome with a length of 4,233,985 bp and the GC content is 62.56%. Genomic analysis showed that Cobetia sp. D5 contains a set of genes to transport and metabolize DMSP, which can cleave DMSP to produce dimethyl sulphide (DMS) and 3-Hydroxypropionyl-Coenzyme A (3-HP-CoA). DMS diffuses into the environment to enter the global sulfur cycle, whereas 3-HP-CoA is catabolized to acetyl CoA to enter central carbon metabolism. Thus, this study provides genetic insights into the DMSP metabolic processes of Cobetia sp. D5 during a marine algal bloom, and contributes to the understanding of the important role played by marine bacteria in the global sulfur cycle.

To Explore the Mechanism of "Fuzi-Guizhi" for the Treatment of Osteoarthritis on the Basis of Network Pharmacology and Molecular Docking.

OBJECTIVE: The objective of this study is to analyze and verify the main drug components and targets of "Fuzi-Guizhi" in the treatment of osteoarthritis by using the network pharmacology platform. METHODS: The integrated pharmacology of "Fuzi-Guizhi" was analyzed by using the platform of integrated pharmacology of traditional Chinese medicine to explore its mechanism in the treatment of osteoarthritis. By establishing an arthritis model in vitro, the pharmacological effect of "aconitecassia twigs" on articular cartilage was evaluated and conducted for molecular docking. RESULTS: 28 candidate active components, 37 compound targets, and 583 osteoarthritis-related potential targets were screened, and 10 key target processes were screened in the protein interaction network model. Enrichment analysis showed that the 10 core targets involved 958 GO biologic function items and 76 KEGG signal pathways, which were mainly related to apoptosis and mitochondrial functional metabolism and "Fuzi-Guizhi" drug-containing serum inhibited the expression of Caspase-3 mRNA and protein in chondrocytes and promoted the synthesis of ATP. CONCLUSION: Our research is preliminary that the mechanism of action of "Fuzi-Guizhi" may inhibit chondrocyte degeneration by resisting mitochondrial apoptosis, and further experimental research is required to determine.

[Establishment of indices for soybean low temperature damages in key growth stage in high cold region]. / é«˜å¯’åŒºå¤§è±†å ³é”®ç”Ÿè‚²æœŸä½Žæ¸©å†·å®³æŒ‡æ ‡æž„å»º.

Establishment of indices for low temperature damage of soybeans is important for systematically analyzing the adaptation strategies to climate change and collaborative adaptation technology for disaster prevention and mitigation and other stresses in high cold region. Based on historical data of low temperature damage and phenophase of soybean from 1980 to 2020 and daily temperature data from 78 meteorological stations in Heilongjiang Province, we used GIS to match the phenophase and meteorological data, by considering the accumulated temperature anomaly in different growth stages, and constructed a comprehensive soybean low temperature damages index (CSCDI) in high cold region. Using K-S distribution fitting test and the lower limit value of confidence intervals, we constructed the level index of soybean low temperature damage. The results showed that the CSCDI lower limits of mild, moderate and severe low temperature damage were 0.061, 0.115 and 0.237 from sowing to emergence stage, were 0.072, 0.152 and 0.312 from emergence to flowering, and 0.133, 0.245 and 0.412 from flowering to maturity, respectively. The time distribution of soybean low temperature damage inversed by CSCDI in Heilongjiang Province was consistent with the historical disaster records. The spatial distribution showed obvious latitude characteristics, with the frequency of low temperature damage increasing gradually from south to north.

Bispecific antibody simultaneously targeting PD1 and HER2 inhibits tumor growth via direct tumor cell killing in combination with PD1/PDL1 blockade and HER2 inhibition.

Immune checkpoint blockade has shown significant clinical benefit in multiple cancer indications, but many patients are either refractory or become resistant to the treatment over time. HER2/neu oncogene overexpressed in invasive breast cancer patients associates with more aggressive diseases and poor prognosis. Anti-HER2 mAbs, such as trastuzumab, are currently the standard of care for HER2-overexpressing cancers, but the response rates are below 30% and patients generally suffer relapse within a year. In this study we developed a bispecific antibody (BsAb) simultaneously targeting both PD1 and HER2 in an attempt to combine HER2-targeted therapy with immune checkpoint blockade for treating HER2-positive solid tumors. The BsAb was constructed by fusing scFvs (anti-PD1) with the effector-functional Fc of an IgG (trastuzumab) via a flexible peptide linker. We showed that the BsAb bound to human HER2 and PD1 with high affinities (EC50 values were 0.2 and 0.14 nM, respectively), and exhibited potent antitumor activities in vitro and in vivo. Furthermore, we demonstrated that the BsAb exhibited both HER2 and PD1 blockade activities and was effective in killing HER2-positive tumor cells via antibody-dependent cellular cytotoxicity. In addition, the BsAb could crosslink HER2-positive tumor cells with T cells to form PD1 immunological synapses that directed tumor cell killing without the need of antigen presentation. Thus, the BsAb is a new promising approach for treating late-stage metastatic HER2-positive cancers.

A follow-up study in children with status epilepticus during sleep: From clinical spectrum to outcome.

PURPOSE: To evaluate the correlation between clinical spectrum and therapeutic outcomes and neuropsychological deficits in children with status epilepticus during sleep (SES). METHODS: The clinical spectrum of patients with SES was defined as follows: status epilepticus of benign childhood epilepsy with centro-temporal spikes (SEBECTs), atypical benign focal epilepsy during childhood (ABFEC), non-idiopathic focal epilepsy (NIFE), and Landau-Kleffner syndrome (LKS). SES cases were divided into 4 groups according to neuropsychological findings before treatment: developmental delay/intellectual disability (DD/ID), cognitive impairment (CI), attention deficit and/or hyperactivity behaviors (AHD), and normal group (NG). The therapeutic outcomes were classified into 3 groups: satisfactory response, recurrence, and seizure control. RESULTS: A total of 39 cases (24 males and 15 females) were recruited, including 3 cases with SEBECTs, 26 with ABFEC, 8 with NIFE [2 with focal cortical dysplasia (FCD)], and 2 with LKS. There were 7 patients in the DD/ID group, 8 in the CI group, 19 in the AHD group, and 5 in the NG group. Neuropsychological outcomes were significantly different among clinical spectrum (P < 0.001), and neuropsychological deficits frequently occurred in the ABFEC group or in the NIFE group. Besides, 18 patients in the satisfactory group had satisfactory response to medicine or surgery (2 out of 18 cases with FCD), whereas recurrence was observed at least one session within one year in 16 cases in the recurrence group, and no improvement in spike-wave index and cognition/behavior was noted in 5 patients in the seizure control group, although seizure could be controlled. There were significant differences in therapeutic outcomes among clinical spectrum (P = 0.041), with the worst outcomes in the NIFE group (only 1 out of 8 with satisfactory good response). CONCLUSIONS: It is important to categorize patients with SES into epilepsy syndromes, including SEBECTs, ABFPEC, NIFE, and LKS; the clinical spectrum may be a significant determinant to influence the outcomes of SES, including neuropsychological deficits and therapeutic outcomes.

[Time-series characteristics of drought and flood in spring soybean growing season and its effect on soybean yield in Heilongjiang Province, China]. / é»‘é¾™æ±Ÿçœå¤§è±†ç”Ÿé•¿å­£æ—±æ¶æ—¶åºç‰¹å¾åŠå ¶å¯¹äº§é‡çš„å½±å“.

Under the background of climate change, the spatial-temporal distribution of precipita-tion in Heilongjiang Province is uneven, and drought and flood frequently change, which is not conducive to the safety of soybean production for the province. To clarify the influence mechanism of drought and flood in the growing season on soybean yield in Heilongjiang Province, we analyzed the time-series characteristics of drought and flood in soybean growing season and its effect on soybean yield in different growth stages, based on data of daily precipitation from 60 meteorological stations during 1961 to 2018 and soybean yield in the same period, with the standardized precipitation index (SPI) as the drought and flood evaluation index. The results showed that, from 1961 to 2018, the influence range of drought in soybean growing season in Heilongjiang Province showed a weak decreasing trend, while that of flood showed a weak increasing trend. In the same period, the intensity of both drought and flood showed a weak increasing trend, with slightly stronger role of flood intensity. The probability of the co-occurrence of drought and flood accounted for 60.3%. The soybean growing season in Heilongjiang Province may become wetter. From 2012 to 2018, the influence range and occurrence intensity of flood were significantly higher than that of drought, six years of the whole or regional flood occurred, in which five years were moderate degrees. The effects of drought and flood on soybean yield differed across regions in soybean growing season. The effect of flood on soybean yield was significantly stronger than that of drought in the Northwest, North and East, and were similar in the Midland, while in the Southwest, South and Southeast, the effect of drought was much greater than that of flood. The fluctuation of soybean yield was closely related to drought and flood during bloom-seed-filling period. Among them, in the Northwest, Southwest, Midland, South and Southeast of Heilongjiang, soybean yield would reach a high level when there was a little bit more precipitation, but the moderate and above-moderate levels of flood would cause the reduction. In the North, the fluctuation of soybean yield was mainly affected by flood, while in the East, the effects of drought and flood on soybean yield were similar.

Differential expression of AURKA/PLK4 in quiescence and senescence of osteosarcoma U2OS cells.

This study aimed to identify co-expressed differentially expressed genes (DEGs) in quiescence and senescence of osteosarcoma (OS) U2OS cells and investigate their biological functions. GSE94805 from Gene Expression Omnibus database was extracted, involving 12 samples of OS U2OS cells (4 quiescence, 4 senescence, and 4 control samples). After analysis of DEGs by limma package, VENN analysis was performed to identify co-expressed DEGs in quiescence and senescent. The Cytoscape software was used to construct an interactive network of co-expressed DEGs. Finally, box-plot was drawn for the co-expressed DEGs in sub-network. Besides, the relation literatures were selected in GenCLiP database for the co-expressed DEGs. Seven hundred and forty-three DEGs (255 up-regulated genes, 488 down-regulated genes) were obtained in quiescence and 2135 DEGs (1189 up-regulated genes, 946 down-regulated genes) in senescence. Through VENN analysis, 448 DEGs (131 up-regulated genes, 317 down-regulated genes) were co-expressed in quiescent and senescence. In the co-expressed DEGs network, 896 nodes (448 nodes in quiescent, 448 nodes in senescent) were obtained. Finally, 16 co-expressed DEGs were obtained in the sub-network analysis, in which Aurora kinase A (AURKA) and polo-like kinase (PLK4) had been reported in OS. AURKA and PLK4 might be the key genes in quiescence and senescence of OS U2OS cells.

A missense mutation in SLC6A1 associated with Lennox-Gastaut syndrome impairs GABA transporter 1 protein trafficking and function.

BACKGROUND: Mutations in SLC6A1 have been associated mainly with myoclonic atonic epilepsy (MAE) and intellectual disability. We identified a novel missense mutation in a patient with Lennox-Gastaut syndrome (LGS) characterized by severe seizures and developmental delay. METHODS: Exome Sequencing was performed in an epilepsy patient cohort. The impact of the mutation was evaluated by 3H γ-aminobutyric acid (GABA) uptake, structural modeling, live cell microscopy, cell surface biotinylation and a high-throughput assay flow cytometry in both neurons and non neuronal cells. RESULTS: We discovered a heterozygous missense mutation (c700G to A [pG234S) in the SLC6A1 encoding GABA transporter 1 (GAT-1). Structural modeling suggests the mutation destabilizes the global protein conformation. With transient expression of enhanced yellow fluorescence protein (YFP) tagged rat GAT-1 cDNAs, we demonstrated that the mutant GAT-1(G234S) transporter had reduced total protein expression in both rat cortical neurons and HEK 293 T cells. With a high-throughput flow cytometry assay and live cell surface biotinylation, we demonstrated that the mutant GAT-1(G234S) had reduced cell surface expression. 3H radioactive labeling GABA uptake assay in HeLa cells indicated a reduced function of the mutant GAT-1(G234S). CONCLUSIONS: This mutation caused instability of the mutant transporter protein, which resulted in reduced cell surface and total protein levels. The mutation also caused reduced GABA uptake in addition to reduced protein expression, leading to reduced GABA clearance, and altered GABAergic signaling in the brain. The impaired trafficking and reduced GABA uptake function may explain the epilepsy phenotype in the patient.

[Evolution of maize climate productivity and its response to climate change in Heilongjiang Province, China.] / é»‘é¾™æ±ŸçœçŽ‰ç±³æ°”å€™ç”Ÿäº§åŠ›æ¼”å˜åŠå ¶å¯¹æ°”å€™å˜åŒ–çš„å“åº”.

Under the background of climate change, revealing the change trend and spatial diffe-rence of maize climate productivity in-depth and understanding the regularity of maize climatic resources utilization can provide scientific basis for the macro-decision of agricultural production in Heilongjiang Province. Based on the 1981-2014 meteorological data of 72 weather stations and the corresponding maize yield data in Heilongjiang Province, by the methods of step by step revisal, spatial interpolation and linear trend analysis, this paper studied the photosynthetic productivity (PP), light-temperature productivity (LTP), and climatic productivity (CP) of spring maize, and their temporal and spatial variation characteristics, main influencing factors and light energy utilization efficiency, and evaluated the maize climate productivities under different climate scenarios in the future. The results showed that during the study period, the mean PP, LTP and CP in Heilongjiang Province were 26558, 19953, 18742 kg·hm-2, respectively. Maize PP, LTP and CP were high in plains and low in mountains, and gradually decreased from southwest to northeast. PP, LTP and CP presented significantly increasing trends, and the increase rates were 378, 723 and 560 kg·hm-2·(10 a)-1, respectively. The increase of radiation and temperature had positive effect on maize production in Heilongjiang Province. The potential productivity of maize presented significant response to climate change. The decrease of solar radiation led to the decline of PP in western Songnen Plain, but the increased temperature compensated the negative effect of solar radiation, so the downward trend of LTP was slowed. The response to climate warming was particularly evident in North and East, and LTP was significantly increased, which was sensitive to the change of precipitation in southwest of Songnen Plain and part of Sanjiang Plain. The average ratio of maize actual yield to its climate productivity was only 24.1%, there was still 75.9% to be developed. In the future, the warm and wet climate would benefit the improvement of maize climate productivity, while the cold and dry climate would make an adverse impact.

Age-related intraneuronal accumulation of αII-spectrin breakdown product SBDP120 in the human cerebrum is enhanced in Alzheimer's disease.

Spectrins are a part of cytoskeletal platform that lines the intracellular side of plasma membrane, which can be proteolyzed by calcium-sensitive enzymes including calpains and caspases. Caspase-3 mediated αII-spectrin proteolysis results in the release of a 120kDa spectrin breakdown product (SBDP120), known to occur in conditions with cell death. In rodents, intraneuronal SBDP120 accumulation in the forebrain develops with age, which is enhanced in transgenic models of Alzheimer's disease (AD). The present study was set to explore age-related SBDP120 formation and its relevance to AD-type hallmark lesions in the human brains. SBDP120 immunoreactivity (IR) was detected in neuronal somata and dendrites in the cortex and hippocampal formation in postmortem brains from aged (n=10, mean age=84.2) and AD (n=10, mean age=84.8) subjects, but not mid-aged controls (n=10, mean age=58.2). The overall density of SBDP120 IR quantified in the temporal neocortex was increased in the aged and AD groups, more robust in the latter, relative to mid-aged control, while no regional, laminar or cellular association was found between SBDP120 accumulation and Aß deposition or phosphorylated-tau aggregation. In cultured rat retinal ganglion cells (RGC-5), SBDP120 elevation occurred with caspase-3 activation following oxygen as well as serum deprivation, suggestive of SBDP120 formation in stressful conditions with and without apparent neuronal death. These results confirm an age-related intraneuronal SBDP120 accumulation in the human cerebrum that is enhanced in AD. This neuronal change appears to occur independent of amyloid deposition, tau pathology and overt neuronal death.

[Effects of TIEG1 on K562 cell apoptosis and expression of BCL-2/BAX, PTEN].

The aim of this study was to investigate the effect of TIEG1 on K562 cell apoptosis and expression of BCL-2/BAX, PTEN. The different concentration(0, 1, 5, 10, 20 ng/ml) of TIEG1 were used to treat K562 cells, the cell growth inhibition rate was detected by using MTT method. After treating K562 cells with 10.00 ng/ml TIEG1, the cell apoptosis was detected with flow cytometry. The RT-PCR was used to detected the expression levels of BCL-2 /BAX and PTEN. The results showed that TIEG1 displays inhibitory effect on proliferation of K562 cells in time-and dose-dependent manner (r = 0.52, P < 0.05) ; after K562 cells were treated for 6, 12, 24 and 48 h, the IC50 of TIEG1 were 48.19, 18.72, 9.5 and 3.85 ng/ml respectively. After treating K562 cells with 10.00 ng/ml TIEG1 for 0, 6, 12, 24, 48 h, the apoptosis rate were (2.13 ± 0.42)%, (7.79 ± 0.71)%, (11.17 ± 1.37)%, (24.66 ± 0.29)% and (48.60 ± 1.38)% respectively, and there was significant difference between groups(P < 0.05). In process of K562 cell apoptosis, the expression level of BCL-2 gradually decreased (r = 0.48, P < 0.05), meanwhile the expression levels of BAX (r = 0.69, P < 0.05) and PTEN (r = 0.57, P < 0.05) gradually increased. It is concluded that TIEG1 can indue apoptosis of K562 cells and inhibit K562 cell proliferation in time-and dose-dependent manner. In apoptosis process of K562 cells induced by TIEG1, the expression changes of BCL-2/BAX and PTEN associate with the K562 cell apoptosis.

Age-related intraneuronal elevation of αII-spectrin breakdown product SBDP120 in rodent forebrain accelerates in 3×Tg-AD mice.

Spectrins line the intracellular surface of plasmalemma and play a critical role in supporting cytoskeletal stability and flexibility. Spectrins can be proteolytically degraded by calpains and caspases, yielding breakdown products (SBDPs) of various molecular sizes, with SBDP120 being largely derived from caspase-3 cleavage. SBDPs are putative biomarkers for traumatic brain injury. The levels of SBDPs also elevate in the brain during aging and perhaps in Alzheimer's disease (AD), although the cellular basis for this change is currently unclear. Here we examined age-related SBDP120 alteration in forebrain neurons in rats and in the triple transgenic model of AD (3×Tg-AD) relative to non-transgenic controls. SBDP120 immunoreactivity (IR) was found in cortical neuronal somata in aged rats, and was prominent in the proximal dendrites of the olfactory bulb mitral cells. Western blot and densitometric analyses in wild-type mice revealed an age-related elevation of intraneuronal SBDP120 in the forebrain which was more robust in their 3×Tg-AD counterparts. The intraneuronal SBDP120 occurrence was not spatiotemporally correlated with transgenic amyloid precursor protein (APP) expression, ß-amyloid plaque development, or phosphorylated tau expression over various forebrain regions or lamina. No microscopically detectable in situ activated caspase-3 was found in the nuclei of SBDP120-containing neurons. The present study demonstrates the age-dependent intraneuronal presence of an αII-spectrin cleavage fragment in mammalian forebrain which is exacerbated in a transgenic model of AD. This novel neuronal alteration indicates that impairments in membrane protein metabolism, possibly due to neuronal calcium mishandling and/or enhancement of calcium sensitive proteolysis, occur during aging and in transgenic AD mice.

An outbreak of sheep pox associated with goat poxvirus in Gansu province of China.

Three strains of Capripoxviruses (CaPVs) were isolated from an outbreak of sheep pox in Gansu province of China. They were analyzed by P32 gene-based molecular methods and a species-specific PCR based on the RPO30 gene. Two bands which are specific to goat poxvirus (GTPV) were observed after the PCR products of P32 gene were digested with the endonuclease of Hinf I. Moreover, an amplicon of 172 bp, which is specific to GTPV, was amplified from the viruses by using the RPO30 gene-based PCR. Sequence analysis of the P32 genes showed that three nucleotide bases for coding residue of aspartic acid which are located at 163-165 position of P32 gene of sheep poxvirus (SPPV) were absent, and six single nucleotide substitutions which are characteristic of GTPV were present. The viruses were genetically closer to GTPV strains and clustered into the GTPV branch of the phylogenetic tree constructed on the basis of the P32 gene. The results characterized the isolated viruses as GTPV. It is the first report of an outbreak of sheep pox associated with GTPV in China.

[Effect of willed movement therapy on GFAP and SYP expression in rats with cerebral ischemia-reperfusion].

OBJECTIVE: To determine the effect of willed movement on the expression of glial fibrillary acidic protein (GFAP) and synaptophysin (SYP) in adult rats with cerebral ischemia-reperfusion, and explore the mechanism of willed movement in promoting nerve repair and regeneration. METHODS: Adult rat models of cerebral ischemia-reperfusion injury were established by middle cerebral artery occlusion (MCAO) for 2 h followed by a 24-h reperfusion. The models were then divided randomly into 3 groups, namely the model group, environmental modification (EM) group, and willed movement (WM) group. In each group, neurological deficits were evaluated at 3, 7 and 15 days after reperfusion. Immunohistochemistry and immunofluorescence assay were employed to examine the expression of GFAP and SYP in the brain tissue near the ischemic foci. RESULTS: The rats in WM group showed lessened neurological deficits at 15 days and lowered expression of GFAP and SYP at 7 and 15 days after reperfusion compared with the model and EM groups (P<0.05). No significant difference was found in the expression of GFAP or SYP between the model group and EM group at any time points. CONCLUSION: Willed movement can promote the functional recovery of neurological deficits following cerebral ischemia-reperfusion probably in relation to enhanced GFAP and SYP expressions in the ischemic brain tissues.

Genetic variations in the SMAD4 gene and gastric cancer susceptibility.

AIM: To explore the association between mothers against decapentaplegic homolog 4 (SMAD4) gene polymorphisms and gastric cancer risk. METHODS: Five tagging single nucleotide polymorphisms (tSNPs) in the SMAD4 gene were selected and genotyped in 322 gastric cancer cases and 351 cancer-free controls in a Chinese population by using the polymerase chain reaction restriction fragment length polymorphism method. Immunohistochemistry was used to examine SMAD4 protein expression in 10 normal gastric tissues adjacent to tumors. RESULTS: In the single-locus analysis, two significantly decreased risk polymorphisms for gastric cancer were observed: the SNP3 rs17663887 TC genotype (adjusted odds ratio = 0.38, 95% confidence interval: 0.21-0.71), compared with the wild-type TT genotype and the SNP5 rs12456284 GG genotype (0.31, 0.16-0.60), and with the wild-type AA genotype. In the combined analyses of these two tSNPs, the combined genotypes with 2-3 protective alleles (SNP3 C and SNP5 G allele) had a significantly decreased risk of gastric cancer (0.28, 0.16-0.49) than those with 0-1 protective allele. Furthermore, individuals with 0-1 protective allele had significantly decreased SMAD4 protein expression levels in the normal tissues adjacent to tumors than those with 2-3 protective alleles (P = 0.025). CONCLUSION: These results suggest that genetic variants in the SMAD4 gene play a protective role in gastric cancer in a Chinese population.

[Relationships between rice empty grain rate and low temperature at booting stage in Heilongjiang Province].

Six major rice varieties (Longdao 3, Kendao 12, Kongyu 131, Longdao 7, Longjing 16, and Songjing 6) in Heilongjiang Province were treated with low temperature 15 degrees C, 17 degrees C, and 19 degrees C for 2, 4, 6 and 8 days at booting stage, and the relationships between their empty grain rate per panicle and low temperature at booting stage were analyzed by using linear interpolation and linear regression methods. In the province, the critical temperature of sterile-type cool injury was 17 degrees C for sensitive varieties, and 16 degrees C for resistant varieties. The most sensitive period of rice to low temperature was 14-18 days before heading. At 15 degrees C for 8 days, the empty grain rate of Songjing 6 and Kendao 12 increased significantly, while that of Kongyu 131 increased less, suggesting that the cold tolerance of Songjing 6 and Kendao 12 was relatively weak, while Kongyu 131 was insensitive to low temperature. There was a significant correlation between the accumulated cool temperature and the empty grain rate of Kendao 12, Longjing 16, and Kongyu 131 (P<0.01). With the increase of accumulated cool temperature, the rice empty grain rate increased significantly, but the increment varied with rice variety.

[Responses of soil humidity on Songnen Plain to climate change in 1980-2005].

Based on the 1980-2005 observation data of ten-day soil humidity, monthly air temperature, and monthly precipitation during crop growth period (from May to September) from 16 agrometeorological stations on Songnen Plain, the spatiotemporal variation of surface soil (0-30 cm) humidity and its responses to the air temperature and precipitation in study area were analyzed by using statistical method. The results showed that on Songnen Plain, the surface soil humidity during crop growth period in 1980-2005 had a decreasing trend, and tended to be aridified, especially in the west and south parts of the Plain. Before the 1990s, the surface soil on the Plain was relatively humid, but thereafter, the humidity kept decreasing, and partial dryness occurred. In the study period, the mean air temperature during crop growth period had a periodical increase before 1992, with a small fluctuation in a cycle of 6 years, but increased obviously after then. The precipitation during crop growth period had a larger inter-annual variation, with a cycle of 4-5 years. The surface soil humidity during crop growth period was significantly negatively correlated to air temperature and positively correlated to precipitation. Both air temperature and precipitation were the main climatic factors affecting the variation of surface soil humidity on Songnen Plain.

[Experimental study on the possibility of brain damage induced by chronic treatment with phenobarbital, clonazepam, valproic acid and topiramate in immature rats].

OBJECTIVE: To explore the possibility of brain damage induced by several anti-epileptic drugs (AEDs) at therapeutic level to immature brain of rat. METHODS: Totally 160 healthy Spraque-Dawley (SD) rats selected for the study were divided into infant and adult groups. Each age group was treated with phenobarbital (PB), clonazepam (CZP), valproic acid (VPA), topiramate (TPM) or normal saline respectively for 2 or 5 weeks with 8 rats in each group. The steady-state plasma concentrations of AEDs at the experimental dosage were coincided with the range of clinical therapeutic concentrations. Drug levels in plasma were determined by fluorescence polarization. Body and brain weights were measured when the rats were sacrificed. Histological studies on the tissues of frontal lobes and hippocampus were performed by Nissl staining. And ultrastructural changes of brain were observed by the transmission electron microscopy. Plasma neuron-specific enolase (NSE) was determined by ELISA. Expression of apoptosis-related proteins Bcl-2 and Bax in neurons was detected by immunohistochemistry. Neuronal apoptosis was detected by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL). RESULTS: (1) There were no significant differences in brain weight among all adults groups. While remarkable reduction of brain weight was observed in immature rats exposed to CZP or PB (P < 0.01) for long term. (2) Significant neurodegeneration, neuronal necrosis and decrease in the number of neurons can be observed in the immature rats exposed to CZP or PB for long period. (3) For immature rats, concentration of plasma NSE was increased even after short-term treatment with PB [(8.84 +/- 2.10) nmol/L] compared with control group [(6.27 +/- 1.27) nmol/L] (P < 0.01). And it was increased in immature rats exposed to CZP [(8.15 +/- 1.67) nmol/L] or PB [(8.07 +/- 1.27) nmol/L] for long term compared with controls [(6.02 +/- 1.20) nmol/L] (P < 0.01). But there were no significant differences between AEDs-treated adult rats and control rats. (4) The expression of Bcl-2 and Bax protein in mature brain did not change at therapeutic level. In contrast, expression of Bax protein in the frontal lobe was increased significantly in immature rats receiving CZP and PB for long period compared with control. (5) The number of TUNEL positive cells in immature rats exposed to CZP or PB for long term was obviously increased. CONCLUSIONS: PB and CZP may result in remarkable histological abnormalities, neuronal apoptosis and necrosis in immature brain. The brain damage induced by PB was more serious and persistent than that induced by CZP.