Effects of post-traumatic stress disorder on the excitability of glutamatergic and GABAergic neurons in dorsal and ventral hippocampus in mice / 生理学报

The purpose of this study was to investigate the effects of post-traumatic stress disorder (PTSD) on electrophysiological characteristics of glutamatergic and GABAergic neurons in dorsal hippocampus (dHPC) and ventral hippocampus (vHPC) in mice, and to elucidate the mechanisms underlying the plasticity of hippocampal neurons and memory regulation after PTSD. Male C57Thy1-YFP/GAD67-GFP mice were randomly divided into PTSD group and control group. Unavoidable foot shock (FS) was applied to establish PTSD model. The spatial learning ability was explored by water maze test, and the changes in electrophysiological characteristics of glutamatergic and GABAergic neurons in dHPC and vHPC were examined using whole-cell recording method. The results showed that FS significantly reduced the movement speed, and enhanced the number and percentage of freezing. PTSD significantly prolonged the escape latency in localization avoidance training, shortened the swimming time in the original quadrant, extended the swimming time in the contralateral quadrant, and increased absolute refractory period, energy barrier and inter-spike interval of glutamatergic neurons in dHPC and GABAergic neurons in vHPC, while decreased absolute refractory period, energy barrier and inter-spike interval of GABAergic neurons in dHPC and glutamatergic neurons in vHPC. These results suggest that PTSD can damage spatial perception of mice, down-regulate the excitability of dHPC and up-regulate the excitability of vHPC, and the underlying mechanism may involve the regulation of spatial memory by the plasticity of neurons in dHPC and vHPC.

Specific targeting of angiogenesis in lung cancer with RGD-conjugated ultrasmall superparamagnetic iron oxide particles using a 4.7T magnetic resonance scanner / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Angiogenesis is an essential step for tumor development and metastasis. The cell adhesion molecule avβ3 integrin plays an important role in angiogenesis and is a specific marker of tumor angiogenesis. A novel avβ3 integrin- targeted magnetic resonance (MR) imaging contrast agent utilizing Arg-Gly-Asp (RGD) and ultrasmall superparamagnetic iron oxide particles (USPIO) (referred to as RGD-USPIO) was designed and its uptake by endothelial cells was assessed both in vitro and in vivo to evaluate the angiogenic profile of lung cancer.</p><p><b>METHODS</b>USPIO were coated with -NH3+ and conjugated with RGD peptides. Prussian blue staining was performed to evaluate the specific uptake of RGD-USPIO by human umbilical vein endothelial cells (HUVECs). Targeted uptake and subcellular localization of RGD-USPIO in HUVECs were confirmed by transmission electron microscopy (TEM). The ability of RGD-USPIO to noninvasively assess avβ3 integrin positive vessels in lung adenocarcinoma A549 tumor xenografts was evaluated with a 4.7T MR scanner. Immunohistochemistry was used to detect avβ3 integrin expression and vessel distribution in A549 tumor xenografts.</p><p><b>RESULTS</b>HUVECs internalized RGD-USPIO significantly more than plain USPIO. The uptake of RGD-USPIO by HUVECs could be competitively inhibited by addition of free RGD. A significant decrease in T2 signal intensity (SI) was observed at the periphery of A549 tumor xenografts at 30 minutes (P < 0.05) and 2 hours (P < 0.01) after RGD-USPIO was injected via the tail vein. Angiogenic blood vessels were mainly distributed in the periphery of tumor xenografts with positive avβ3 integrin expression.</p><p><b>CONCLUSIONS</b>RGD-USPIO could specifically label avβ3 integrin and be taken up by HUVECs. This molecular MR imaging contrast agent can specifically evaluate the angiogenic profile of lung cancer using a 4.7T MR scanner.</p>

Association of insulin, insulin-like growth factor and insulin-like growth factor binding proteins with the risk of colorectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the association of the changes of serum insulin, insulin-like growth factor (IGF-1), insulin-like growth factor binding proteins(IGFBPs), body mass index (BMI), waist and hip circumference ratio(WHR) with the genesis of colorectal cancer.</p><p><b>METHODS</b>Sera from 244 colorectal cancer patients before operation, 371 patients after operation and 150 healthy subjects were assayed for insulin, leptin, IGF-1, IGFBP-1 and IGFBP-3 by the enzyme-linked immunosorbent assay. SPSS 13.0 statistics software was applied to analyze the data.</p><p><b>RESULTS</b>The serum levels of insulin, IGF-1 and the ratio of IGF-1/ IGFBP-3 in colorectal cancer patients before and after surgical treatment were significantly higher than those in controls. The serum levels of IGFBP-3 in patients before and after operation were significantly lower than those in controls, and the differences were significant(P=0.015,P=0.001, respectively). The BMI in colorectal carcinoma patients was not significantly different to the healthy controls(P>0.05). The WHR in colorectal carcinoma patients was higher than that in healthy subjects, and the difference was significant(P=0.003, P=0.035 respectively). The WHR in colon cancer patients was different to that in rectal cancer patients(P=0.046). The WHR and BMI in colon carcinoma patients were positively correlated with the serum insulin level and the value of IGF/IGFBP3. The WHR and BMI were negatively correlated with IGFBP3. The WHR and BMI were not correlated with IGF-1 and IGFBP1.</p><p><b>CONCLUSIONS</b>The serum insulin, IGF-1 levels and the value of IGF-1/IGFBP-3 are significantly increased in colorectal cancer patients, and serum IGFBP-3 level is markedly decreased, which may be related to the genesis of colorectal cancer, but are not correlated with the progress and improvement of colorectal cancer. Central adipositas may be a risk factor for the genesis of colon cancer.</p>

The expression of VEGF,COX2 and mPGES mRNA in colon cancer / 肿瘤研究与临床

Objective To study the expression of VEGF,Cox2 and mPGES in colon cancer.Methods VEGF,Cox2 and mPGES mRNA expression in 32 paired samples(tumor and adjacent normal tissue)were de- termined by using real time RT-PCR.Results VEGF was overexpressed in 19 of 32(59.3 %)tumor tissues compared with that in 6 of 32(18.7 %)adjacent normal tissue;COX2 was overexpressed in 20 of 32(62.5 %) tumor tissues compared with that in 5 of 32(15.6 %)adjacent normal tissue;mPGES was overexpressed in 24 of 32(75 %)tumor tissues compared with that in 9 of 32(28.12 %)adjacent normal tissue.Conclusion Our result suggested that VEGF165,mPGES and COX2 overexpressed in colon cancer.

A NEW STRAIN OF SPOROCYTOPHAGA / 微生物学通报

A strain of cellulolytic bacterium was isolated from soil by cellulostic plate. The morphological and physiological properties of this strain were studied. According to Bergey's Manual of Determinative Bacteriology ,the strain was identified as a new strain of the Sporocytophaga.

STUDY ON THE PROPERTIES OF POLY(?-HYDROXYBUTYRATE)DEPOLYMERASE / 微生物学通报

Three strains having degrading poly(?-hydroxybutyrate)(PHB) activity were isolated from activated sludge of different ecological environments and areas,named DS9701, DS9710 and DS9713.The properties of PHB depolymerase produced by DS9701, DS9710 and DS9713 were studied. All the PHB depolymerases are extracellular enzyme and are induced enzyme. The time that enzyme activities of the PHB depolymerases reach the maximum is 96 hours after inoculation. The apparent optimal temperature range for crude enzymes extract is 40℃～45℃.

Selection High-Yield PHB Depolymerase Producing Strain with UV / 微生物学通报

Conidial suspension was obtained from the Penicillium sp. DS9713a which could decompose PHB. Through screening a lot of mutants with the methods of transparent zones and flask culture, five strains were selected from starting strain treated with UV and their activity were higher than the original .The best mutant strain named DS9713a-CS01, it's enzyme activity was as 197.42% high as that of the original ,furthermore, the characters of crude enzyme were studied.