The article mainly presents the key problems in class III bio-safety lab,including air-flow distribution,pressure gradient of the room,and the stability of pressure.Scientific methods for solving all the problems are also considered,which offer the theory evidence for the design of negative pressure control system in class III bio-safety lab.Volatile blow control and heat exchanger are recommended to be used in the negative pressure control system in class III bio-safety lab for energy conservation.

Objective To explore the neurovascular distribution around multifidus muscles in the low back and its clinical significance via regional dissection.Methods Five cadavers were dissected in the low back.The anatomical relationships between the longissimus thoracis,iliocostalis and the start-stop,direction and position of multifidus muscles were observed.Branches,distribution and the characteristics of the erector spinae muscle,the lateral branches of spinal nerves and blood vessels were examined.Then measured the distances from the emerging point of the lateral cutaneous branches of spinal nerves to the spinous processes.Results After removed the deep fascia,the longissimus thoracis was found medially and the iliocostalis was found laterally.The muhifidus muscles located deeply to the longissimus and the iliocostalis muscles.The lateral branches of the posterior rami of the spinal nerves and the dorsal branches of lumbar blood vessels run in the multifidus muscle gaps.Conclusion The multifidus muscle gaps contain plenty of neurovascular bundles.Surgery involving the low back often takes the advantage of the gaps between multifidus muscles.Therefore,surgeons should take caution to avoid damaging the lateral branches of the posterior rami of the spinal nerves and the dorsal branches of lumbar vessels during low back surgery.

Objective To study the step aceuracy of 252Cf neutron afterloading radiotherapy machine and the dose deviation caused by step deviation.Methods EBT3 film was used to measure the steps of the 252Cf neutron source,and then the center of each 252Cf neutron source was identified by measuring the optical density value by using the ImageJ software.Double ion chambersmethod was used to measure the dose deviation dlue to the 252 Cf neutron source position shift.Results 252 Cf neutron source step accuracy may amount to 0.01 mm using EBT3 film measurement,when 252Cf neutron source position deviation is less than 3 mm,the dose deviation is less than 2.5％.Conclusions The study on the step accuracy and position deviation of the 252Cf neutron source can provide a reference for the quality control standard of the 252Cf neutron afterloading radiotherapy machine.

Annulate lamellae (AL) in oocytes of eel, Anguilla japonica have been observed with electron microscopy. Two types of AL have been found in the cytoplasm of these cells, one of which is the common type, characterized by a stack of parallelly arranged lamellae with annuli (or rings) as shown in figure 1, another is a rare one, which appears as alternative arrangement of parellel lamellae with annuli and membrane-like structures as shown in figures 2～4. The only difference between them is the presence of membrane-like structure in the latter. The origin and function of the membrane-like structure have not been found out yet. It is suggested that this structure might be similar to above-mentioned lamellae in origin and might be a "buffer" in function.

Objective To explore the possibility that rat bone mesenchymal cells (BMSCs) can differentiate into hepatocytes under the affection of fetal liver filtrate. Methods PAS and green indigo dye were used to detect glycogen and differential level of hepatocytes, respectively. The concentration of ALT, AST, ALP in the culture supernatant were served as markers of hepaocyte function. Results Fourteen days after induced by the fetal liver filtrate, BMSCs changed their shapes into polygon, oval or round. Some of BMSCs were positive for AFP and ALB at 7 days after induction, then the number of positive cells increased, and most of BMSCs expressed AFP and ALB till 21days. The PAS reaction and indocyanine green(ICG) intaking also appeared at 7days. Enzyme in supernatant such as ALT, AST, ALP were fristly detected at 7days and peaked at 14days,then the level declined. Conclusion The fetal rat liver filtrate was able to induce BMSCs into cells with function and characteristics of hepatocytes.

Abstract: In order to investigate immune protection against swine-origin influenza virus (S-OIV) A H1N1, the helper-dependent adenovirus vector (HDAd) system was exploited to construct recombinant HDAd encoding hemagglutinin (HA). The HA gene was synthesized and cloned to the HDAd backbone. Then, the HDAd/HA DNA molecules were transfected into 293Cre4 cells with calcium phosphate. The cells were infected by helper virus 16 hours after the transfection. The 293Cre4 cells were coinfected with HDAd/HA and the helper virus for large-scale preparation of HDAd/HA. The HDAd/HA was obtained and purified twice with CsCI density ultracentrifugation and observed morphologically under transmission electron microscope, and the expression of HA protein was analyzed with RTPCR. Recombinant HDAd/HA expressing HA protein was successfully constructed which could pave the way for in vivo investigation on immunogenicity and efficacy against S-OIV A H1N1 infection.
Adenoviridae ; Cell Line ; Cloning, Molecular ; Genetic Vectors ; Helper Viruses ; Hemagglutinin Glycoproteins, Influenza Virus ; biosynthesis ; Humans ; Influenza A Virus, H1N1 Subtype

Objective To compare the dosimetric difference between jaw tracking technique (JTT) and static jaw technique (SJT) in dynamic intensity-modulated radiotherapy (IMRT) for preoperative radiotherapy of rectal cancer patients.Methods Jaw tracking and static jaw were used to develope the intensity-modulated plans for 10 patients respectively.For all the patients,the dose to surrounding tissues was minimized as low as possible,the 95％ volume of the planning target volume (PTV) and planning gross target volume (PGTV) satisfy the prescribed dose.The doses of the planning target volumes,organs at risk and normal tissue were detected by dose-volume histogram.Two groups of treatment plan dose were verified by ionization chamber array 2D-Array 729 and OCTAVIUS (PTW) phantom.Results The treatment plans of two groups could satisfy the clinical requirements.There was no significant difference between the maximum and the mean dose of target.The volumes of jaw tracking dynamic intensity-modulated radiotherapy were lower,including the V5,V10,V20,V30,V40 (volumes receiving 5,10,20,30 and 40 Gy,respectively),mean dose(D) for body and V10,V20,V30,D for bilateral femoral head,bladder,and small intestine.There was significant difference for the results (t =-2.32-12.24,P ＜0.05).The verification results showed that the treatment plans were all passed the dosimetric verification.Conclusions Jaw tracking intensity-modulated radiotherapy and jaw fixed IMRT plan could achieve equal dose coverage in patients with rectal cancer,while jaw tracking techniques could reduce normal tissue dose and organs at risk dose.

BACKGROUND: Studies of biological characteristics of mesenchymal stem cells (MSCs) and regulatory factors that influenced the differentiation of MSCs have shown that the proportion of the natural differentiation from in vitro primarily cultured MSCs into hepatocytes was low, and to select a suitable inductor is important to enhance the differentiation of MSCs into hepatocytes.OBJECTIVE: To verify the feasibility of induced differentiation of rat bone marrow MSCs (BMSCs) into hepatocytes using the combination of hepatocyte growth factor (HGF), epidermal growth factor (EGF) and fibroblast growth factor (FGF-4).DESIGN, TIME AND SETTING: The cytological in vitro study was performed at the Experimental Center, Weifang Medical College in August 2007.MATERIALS: Totally 40 Sprague-Dawley rats were supplied by the Experimental Animal Center, Weifang Medical College.METHODS: Rat BMSCs were incubated by adherent method. BMSCs at passage 3 were assigned to 2 groups. BMSCs in the blank control group were treated with L-DMEM containing 10% fetal bovine serum. BMSCs in the combination group were treated with 10 μg/L FGF, 8 μg/L HGF and 8 μg/L EGF following above-mentioned procedures.MAIN OUTCOME MEASURES: Inverted microscope was used to observe the morphological changes in cells.Immunofluorescence method was used to observe the expression of alpha-fetoprotein (AFP) and albumin (ALB). PAS was employed to detect the expression of glycogen. Fox green intake experiment was conducted. Enzymology was utilized to test the contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP).RESULTS: BMSCs in the combination group presented polygonal, orbicular or round shape. BMSCs in the blank control group remained spindle. BMSCs in the combination group were positive for AFP and ALB at day 14 following culture, and a few PAS-positive and fox green-positive cells were found at day 7. Positive cells became more over time. Synthesis of ALT, AST and ALP was detected at day 14, reached a peak at 21 days, and then decreased. Above-described indexes were negative in the blank control group.CONCLUSION: After induced by the FGF, HGF and EGF, BMSCs have the ability to differentiate into hepatocytes in vitro.

Objective To investigate the combination application of the intracranial buried electrode and electrical stimulation techniques in excising the epileptogenic zone in the central zone.Methods Seven patients with epileptogenic zone located close to or in the central zone of brain were recruited in the present study.The lone term ECoG monitoring and electrical stimulation of the codex were performed to identify the epileptogenic zone and the central zone of the brain after patients received intracranial electrode implants.The epileptogenic zone was excised with maximum preservation of the cen-tral zone.The patients were follow-up for 6 to 12 months,the outcomes were evaluated based on the Engel's scale and the Karnofsky(KPS)score.Results Seven patients did not experience any seizures and their Engei's and KPS scores were markedly improve after operation.Conclusions Intracranial buried electrodes and cortical electrical stimulation can guide the resection of epileptogenic zone in the central zone.Patients have no seizure and no serious dysfunction after operation and their quality of life was improved markedly.

Objective To identify hepatitis C virus(HCV)-specific cytotoxicity T lymphocytes (CTL)epitopes by the combination of T epitopes prediction software and in vitro assays.Methods HCVspecific CTL epitopes were predicted by T epitope prediction software Rankpep and then candidate HCV-specific CTL epitopes were selected.Candidate HCV-specific CTL epitopes were used to stimulate PBMC of HCV-infected patients and healthy volunteers.and then enzyme-linked immunospot(ELISPOT)and intracellular cytokine staining(ICS)were used to measure the frequencies of IFN-γ-producing cells in total PBMC and the percentages of IFN-γ+CD8+T cells in total CD8+T cells,respectively.Results Five candidate CTL epitopes[NS3 450(TVPQDAVSR),NS3 594(GPTLLYRL),Ns4b 78(sMMAFSAAL),NS5a 416(SEENVSVVF)and NS5a 367(TVSSALAEL)]were used to stimulate PBMC of ten HCV-infected patients and two healthy volunteers.PBMC of seven HCV-infected patients secreted IFN-γ while PBMC of healthy volunteers did not produce IFN-γ.The frequencies of peptide-specific IFN-γ-producing cells ranged from 5 to 36 SFC/105 PBMC and the percentages of peptide-specific IFN-γ+CD8+T cells ranged from 0.02%-0.25%.Conclusion Resuhs of ELISPOT assay and ICS assay confirm that these five peptides NS3 450,NS3 594,NS4b 78,NS5a 416 and NS5a 367 are identified as Hovel HCV-specific CTL epitopes.