西昆仑山区高等真菌的研究

本文报道了西昆仑山区和喀喇昆仑山区高等真菌39种,其中我国新纪录4种。     

Ecological Risk Assessment of Arsenic and Metals in Surface Sediments from Estuarine and Coastal Areas of the Southern Bohai Sea,China

Distribution and magnitude of arsenic and metals in surface sediments collected from the coastal and estuarine areas of the southern Bohai Sea, China, were investigated. Sediments from the estuarine and coastal areas of the Jie and Xiaoqing Rivers contained highest concentrations of arsenic, cadmium, copper, mercury, and zinc. Mean concentrations of Cu, Zn, Cr, Pb, and Cd were higher than background concentrations determined for the areas. The magnitude of both enrichment factors (EF) and geoaccumulation indices (I_geo) suggested that pollution with As and metals was occurring along estuarine and coastal areas of the southern Bohai Sea. Risk analysis also suggested that concentrations of As and metals were sufficiently elevated as to cause adverse biological effects in the study area. According to the ecological risk index (RI) values, the upstream of the Jie River has a very high ecological risk for the waterbody. The data provided in this study are considered crucial for controlling and remediation of As and metals’ pollution of the southern Bohai Sea.     

Overexpression of Small Heat Shock Protein LimHSP16.45 in Arabidopsis Enhances Tolerance to Abiotic Stresses

Small heat shock proteins (smHSPs) play important and extensive roles in plant defenses against abiotic stresses. We cloned a gene for a smHSP from the David Lily (Lilium davidii (E. H. Wilson) Raffill var. Willmottiae), which we named LimHSP16.45 based on its protein molecular weight. Its expression was induced by many kinds of abiotic stresses in both the lily and transgenic plants of Arabidopsis. Heterologous expression enhanced cell viability of the latter under high temperatures, high salt, and oxidative stress, and heat shock granules (HSGs) formed under heat or salinity treatment. Assays of enzymes showed that LimHSP16.45 overexpression was related to greater activity by superoxide dismutase and catalase in transgenic lines. Therefore, we conclude that heterologous expression can protect plants against abiotic stresses by preventing irreversible protein aggregation, and by scavenging cellular reactive oxygen species.     

Association of deoxyribonuclease I genetic polymorphisms with myocardial infarction in Han Chinese

Deoxyribonuclease I gene exhibits polymorphisms, including a single nucleotide polymorphism (A2317G) and a 56 bp variable number of tandem repeat, designated as HumDN1. G2317 was regarded as an independent risk factor for Japanese myocardial infarction (MI) patients. We investigated the association between either A2317G or HumDN1 polymorphism of deoxyribonuclease I gene and MI in Han Chinese population. A2317G and HumDN1 polymorphisms in 278 MI patients and 297 unrelated controls were detected by PCR and PCR-restriction fragment length polymorphism. Plasma lipids were measured in fasting state by biochemical methods. A new HumDN1 genotype -HumDN1 4/6 was found in Han Chinese MI patients. Genotype distributions and allele frequencies of A2317G and HumDN1 did not differ between MI patients and control group (all P > 0.05). In addition, none of estimated haplotypes significantly increased or decreased the risk of MI. In analysis of covariance, plasma total cholesterol was observed to be associated with HumDN1 genotypes in MI patients (P = 0.02). Our data suggest HumDN1 genotypes are related to total cholesterol levels in Han Chinese MI patients, but deoxyribonuclease I gene polymorphisms are not associated with susceptibility to MI in Han Chinese.     

Targeting expression of the catalytic domain of the kinase insert domain receptor (KDR) in the peroxisomes of Pichia pastoris

The kinase insert domain receptor (KDR), also known as vascular endothelial growth factor receptor-2 (VEGFR2), is an important therapeutic target for the treatment of cancer because of its crucial role in angiogenesis, which is fundamental to the malignancy of tumors. Here, we expressed the catalytic domain of KDR in Pichia pastoris under the control of the AOX1 promoter. In order to facilitate its purification and detection, His-tag and green fluorescent protein (GFP) were fused to the N-terminus of KDR. At the same time, a peroxisomal targeting signal 1 (SKL) was fused to the C-terminus to avoid the potential negative effect on the host cell. The highly expressing clone K1 was selected by GFP fluorescence intensity analysis using flow cytometry (FCM). Furthermore, the GFP-KDR-SKL fusion protein was proved to be correctly targeted to the peroxisomes of P. pastoris by colocation with blue fluorescent protein-SKL. The expression of GFP-KDR-SKL led to extensive phosphorylation of endogenous proteins and significantly inhibited cell growth. However, the expression was not lethal to the cells. Both in vitro biological activity assay and inhibition rate assay demonstrated that the purified GFP-KDR-SKL fusion protein exhibited high kinase catalytic activity and could be used as a target for anticancer drug screening.     

New Insights into FAK Phosphorylation Based on a FAT Domain-Defective Mutation

Mounting evidence suggests that the FAK N-terminal (FERM) domain controls FAK phosphorylation and function; however, little is known regarding the role of the C terminal (FAT) domain in FAK regulation. We identified a patient-derived FAK mutant, in which a 27-amino acid segment was deleted from the C-terminal FAT domain (named FAK-Del33). When FAK-Del33 was overexpressed in specific tumor cell lines, Y397 phosphorylation increased compared with that observed in cells expressing FAK-WT. Here, we attempt to unveil the mechanism of this increased phosphorylation. Using cell biology experiments, we show that FAK-Del33 is incapable of co-localizing with paxillin, and has constitutively high Y397 phosphorylation. With a kinase-dead mutation, it showed phosphorylation of FAK-Del33 has enhanced through auto-phosphorylation. It was also demonstrated that phosphorylation of FAK-Del33 is not Src dependent or enhanced intermolecular interactions, and that the hyperphosphorylation can be lowered using increasing amounts of transfected FERM domain. This result suggests that Del33 mutation disrupting of FAT''s structural integrity and paxillin binding capacity leads to incapable of targeting Focal adhesions, but has gained the capacity for auto-phosphorylation in cis.     

Confocal Comparison of Corneal Reinnervation after Small Incision Lenticule Extraction (SMILE) and Femtosecond Laser In Situ Keratomileusis (FS-LASIK)

Purpose

To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK).

Methods

In this prospective, non-randomized observational study, 18 patients (32 eyes) received SMILE surgery, and 22 patients (42 eyes) received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity.

Results

The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147), 1 month (P = 0.0243), and 3 months (P = 0.0498), but no difference was detected at the 6-month visit (P = 0.5277). The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, P<0.0001, and r = 0.2567, P = 0.0038 for SMILE group and FS-LASIK group, respectively). The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005).

Conclusions

The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity.