Objective To study the role of bile reflux in the pathogenesis of stress ulcer after acute brain trauma in rat. Methods The animal model was reproduced by Allen's method with modification. The bile acid concentration in the stomach and blood, the pH value of the gastsic content, and ulcer index (UI) were assayed 1, 3, 6, 24 hour after the stress, and they were compared with that of sham injury group. Results In stress group, compared with sham injury group, the amount of bile acid in the stomach was notably increased( P

Objective To investigate the role of epithelial cell apoptosis in the stress-related changes of intestinal mucosa barrier following traumatic brain injury. Methods Sixty-four health male Wistar rats were divided randomly into two groups: (1) traumatic brain injury model group (n =32) ,in which rats suffered from traumatic brain injury by Feeney's method; (2) control group ( n = 32) , rats suffered from sham operation. Each group were divided into four subgroups according 6 h, 12 h,24 h, and 48 h after operation ( n = 8, for each subgroup ). Ileum tissue were taken to observed the damage of the intestinal mucosa under microscope and electronmicroscope. The early apoptosis rate of intestinal mucosal cells were analyzed with Annexin Ⅴ-PI double stained and detected by flow cytometry. Results The intestinal mucosa were damaged and the intercellular space of intestinal mucosal were found increased in traumatic brain injury group. The early apoptosis rate of intestinal mucosal epithelial cells was significant increased in traumatic brain injury group than that in control group [6 h: (13.5 ±3.7)% vs (6.1 ± 1.7)%, P＜0.05; 12 h:(66.1±6.0)% vs (5.2±1.1)%, P＜0.05; 24 h:(39.8±4.8)% vs (8.4±2.6)%, P＜0.05;48 h: (7.5 ±1.3)% vs (6.6 ±0.5)%]. Conclusion The increased early apoptosis rate of intestinal mucosal epithelial cells might contribute to the stress-damage of the intestinal mucosa barrier in early stage of traumatic brain injury.

Objective: To observe the effect of oxidative stress on intestinal mucosal barrier dysfunction following traumatic brain injury (TBI). Methods: Seventy-two male Wistar rats were randomly divided into three groups, group B and group C served as TBI models, group A was designated as the normal controlgroup(shame operation). In group C rats were treated with dimethyl sulfoxide(DMSO) prior to TBI, while rats in group A and B were treated with equivalent normal saline. During the experiment period, the morphological changes of intestinal mucosa were observed, and the intestinal mucosal permeability was detected by measuring the level of endotoxin, diamine oxidase(DAO). Superoxide dismutase(SOD), malondiadehycle (MDA), myeloperoxidase(MPO) and xanthine oxidase(XOD) activities were also detected. Results: During the observed period, the intestinal mucosal barrier function was damaged and the intestinal mucosal permeability increased. The content of endotoxin in serum significantly increased(P < 0.05). As early as 3 h after TBI, the DAO activity in the serum began to increase obviously. At 24 hafter TBI it increased to the highest level(P < 0.05).In group TBI the activity of SOD in intestinal mucosal decreased significantly(P < 0.01); however the levels of MDA and the activity of MPO increased significantly (P < 0.01), the activity of XOD increased significantly as well, and then decreased after 6 h. When pr-treatment with DMSO, intestinal mucosal damage was improved, the content of endotoxin in serum was reduced (P < 0.05), and the increased DAO activity in the serum were inhibited (P < 0.05). When compared with group TBI, there was an inhibition in the decreased activity of SOD and the increased level of MDA in group DMSO (P < 0.05), but they were still higher than that of control group(P < 0.05). There were no significant differences in the activity of XOD and MPO between group DMSO and group TBI. Conclusion: The structure and function of intestinal mucosal barrier were damaged following TBI. Oxidative stress played an important role in the intestinal mucosal barrier dysfunction following TBI. Both XOD and activated polymorphonuclear neutrophils(PMN) were the major source of oxygen free radicals.

Laboratory diagnostics is one of the most fast developing medical sciences.But the teaching quality falls behind due to the traditional education model.Based on the concept of ‘three-stage fusion' of the subject and ‘five abilities' of the training objects,‘three-highlight & stereo' teaching style was established and put through the course,which means to emphasize function,practice,effect in optimizing teaching content and methods,and construct stereo platform including information system,online course,laboratory equipments,research activities and teacher training program.The results showed a significant improvement of the students' knowledge mastering and utilizing capability.And the teaching situation was well re-created.Furthermore,the teaching team was much more powerful than ever.It suggests that ‘three-highlight and stereo' teaching style is a successful explore and practice of teaching reform of laboratory diagnostics on adapting for internationalization of education tendency.

One hundred and ten college students, 66 males and 44 females, were studied for the evaluation of vitamin C status by use of the ratio of reduced vitamin C to creatinine in a random urine sample. During the experimental period, the dietary source of creatinine was strictly abstained. After voiding in the morning, the volunteers were weighed and their urine were collected at the end of 1st, 2nd, 4th, 8th, 12th and 24th hr respectively. The contents of reduced vitamin C and creatinine in each collected urine sample were analysed, and then the total amounts in 24 hrs were calculated.The experimental results showed:1. The distribution of the creatinine excretion in 24 hrs was nearly constant.2. The percentage of reduced vitamin C excretion per hour to the total 24 hrs excretion was similar in subjects of different vitamin C status and was lowest in 12 hrs of night urine. A curvilinear regression was given for the percentage of reduced vitamin C excretion in relation to the time.3. The ratio of reduced vitamin C (as mg) to creatinine (as gm) and the ratio of reduced vitamin C to creatinine (as mg) per body weight (as kg) were calculated from their contents in 12 hrs urine in those who exc- reted reduced vitamin C in urine less than 80 mg in 24 hrs. The relationship between these two ratios and the excretions of reduced vitamin C in 24 hrs urine was studied and four equations of curvilinear regressions were given.4. According to these equations, the correlated values of vitamin C/ crcatinine and vitamin C/creatinine/body weight in random urine samples in respect of four different grades of vitamin C excretion of 24 hrs urine were recommended.It was shown to be a new simplified method for evaluating the nutritional status of vitamin C in human body. The practical aspect of its application was discussed.

The nutritional and food hygienic character of the new developed soy protein concentrate and soy protein isolate in Heilongjiang province were studied by chemical analysis and rat experiment. These products have not yet been reported in China. The results indicated that the content of protein of soy protein concentrate and isolate was 69.76 and 83.11%(as anhydr-ate basic), the PER 2.00 and 1.34, the apparent digestibility 77.54 and 85.72%, the true digestibility 84.33 and 93.19%, the biological value 79.80 and 62.54%, the NPU 67.39 and 58.28% respectively.The essential amino acid composition of the two samples was the same as the products prepared in the other countries. By the hematological and pathological examination in rats, the contents of serveral harmful substan- ces were allowable or not detected. The authors belived that the nutritional quality of the two soy protein products was nearly the same as those in other countries, and its food safety was satisfactory.

Objective To explore the effects of electromagnetic fields (EMFs) on osteogenesis during co-culture of bone mesenchymal stem cells (BMSCs) with osteoblasts in rats.Methods BMSCs and osteoblasts were isolated from Sprague-Dawley rats and cultured.Sub-cultured osteoblasts and BMSCs were seeded in transwell cell-culture-chamber polyester inserts to establish the co-culture system.The co-cultures were then randomly divided into a normal co-culture group and a group exposed to an EMF.Single-cultured BMSCs and osteoblasts were set as a single culture group.The EMF group was exposed to an EMF for 4 hours per day.On the 14th day,cell culture plates or inserts were randomly selected for total RNA extraction and measurement of the mRNA expression levels of Runt-related transcription factor 2,transcription factor 7,alkaline phosphatase,collagen type Ⅰ,bone morphogenetic protein 2 (BMP-2) and bone gamma-carboxyglutamate protein (Osteocalcin gene,OC gene) using real-time PCR assays.Cell culture dishes or inserts were also randomly chosen for Alizarin red staining to detect mineralized nodules.Results The level of osteogenic gene expression in single-cultured BMSCs and osteoblasts was low,while it was much higher in the co-culture group.The level of gene expression in the EMF-exposed and co-cultured group was even higher.Alizarin red staining also showed that calcium mineralized modules had increased in the stimulated,co-cultured system compared with the unstimulated,co-cultured cells.Conclusion EMF exposure can promote osteogenic differentiation of BMSCs and osteoblasts when they are co-cultured.BMP2-mediated cellular interaction might play an important role in osteogenic differentiation induced by EMF exposure.

Objective To study the expressions of aggrecan (Agc) Ⅰ and Ⅱ collagen and Sox9 by bone mar-row mesenchymal stem cells exposed to electromagnetic fields (EMFs) and it's mechanisms involved. Methods Bone marrow mesenchymal stem cells were isolated from Sprague-Dawley rats and cultured in vitro. The third passage cells were harvested and exposed to 15 Hz 1 mT EMFs for 8 h/d. The semi-quantitative reverse transcription-polyme-rase chain reaction (RT-PCR) technique was used to measure parathyroid hormon receptor related peptide (PTHrp) ,Agc Ⅰ and Ⅱ collagen and Sox9 mRNA. Western blotting was used to measure type Ⅱ collagen expression. After the inhibitor of protein kinase A (PKA) H-89 and the inhibitor of protein kinase C (PKC) Go-6976 ( 12 μm) were added, the effects of EMFs on Agc Ⅰ and Ⅱ collagen and Sox9 mRNA expressions were measured again by using RT-PCR, and Western blotting technique. Results The EMFs induced significant increase of mRNA expressions of PTHrp, Agc Ⅰ and Ⅱ collagen and Sox9 in comparison to the controls, and promoted type Ⅱ collagen protein expres-sion. The Agc Ⅰ and Ⅱ collagen expressions decreased after PKA pathway inhibitor H-89 and PKC inhibitor Go-6976 were added, but the mRNA expression of Sox9 was not affected. Conclusion This study shows 15Hz 1mT EMFs can promote mRNA expressions of Agc Ⅰ and Ⅱ collagan and Sox9 of cbondrogenesis differentiation markers in bone marrow mesenchymal stem cells. The effect is correlated with PKA and PKC pathways.

The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures. Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-III calcaneal fracture model by using osteotomy. The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws. Reduction of fracture was evaluated through X radiographs. Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N, representing the partial weight bearing and full weight bearing, respectively, and then the specimens were loaded to failure. Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test. No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading (P=0.06), while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading (P=0.008). The load achieved at loss of fixation of the constructs for the two groups had significant difference: anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N (P=0.008). There was no significant difference between the ultimate displacements. Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading. The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.

Exosomes are vesicular bodies secreted by living cells containing proteins and RNA, and play an important role in the process of physiology and pathology.Pancreatic cancer is one of the common gastrointestinal tumor with high morbidity and mortality.As a hotspot in oncology, exosomes have potential values in the research of development, diagnosis and treatment of pancreatic cancer.This article reviewed the role of exosomes in pancreatic cancer.