Objective To investigate the association between arsenic(+3 oxidation state) methyltransferase (AS3MT) genetic polymorphism and susceptibility to endemic arsenism.Methods Polymerase chain reactionrestriction fragment length polymorphism-single strand conformation polymorphism(PCR-RFLP-SSCP) technology was performed to detect mutations of AS3MT gene intron 8 and exon 9 in genome DNA of the 79 cases and 110 controls.PCR products with abnormal band forms were further sequenced to find the types and sites of mutation.Chi-square test and multivariate Logistic analyses were conducted.Results The incidence of the 9149 base mutation(A→C) in AS3MT gene intron 8(AS3MT-9149) in case group(19.0％,15/79) was lower than that in control group (23.6％,26/110).The incidence of the codon 287 mutation(ATG→AT/CG) in AS3MT gene exon 9(AS3MT-287)in case group(10.1％,8/79) was lower than that in control group (11.8％,13/110).However,statistical analysis indicated no significant difference in both mutations between two groups[AS3MT-9149:odds ratio(OR) =0.59,95％ confidence interval(CI):0.26-1.31,P =0.195; AS3MT-287:OR =0.85,95％ CI:0.32-230,P =0.751].Conclusions There are no significant association between the genetic polymorphisms of AS3MT-9149,AS3MT-287 and the susceptibility to endemic arsenism.Similarly,due to small sample amount,we can not exclude the possibility that these gene polymorphisms are related to susceptibility to endemic arsenism.

This paper proposes a one-way micro valve with a simple structure and a simulation design for the engineering capsule. We have now got its design parameter selection method and its mechanic characteristic from experiments.
Capsules ; Computer Simulation ; Drug Delivery Systems ; methods ; Equipment Design ; Infusion Pumps, Implantable ; Technology, Pharmaceutical ; instrumentation ; methods

Objective To observe the clinical effect of Yiqi Yangyin Huoxue decoction(the function of decoction is to tonify Qi,nourish Yin and enhance blood circulation)on salivary gland response attribute to radiotherapy.Methods This study,carried between January 2005 and December 2005,focused on the effect of Chinese herbs on salivary gland response attribute to radiotherapy.In the treatment group,30 cases took Chinese herbs during the duration of radiotherapy,while in the control group 30 cases were given routine therapy.Results Both groups had finished the radiotherapy,however,in the control group,there were 5 cas- es with a break for 1～2 weeks.For the comparison of the salivary gland change in acute stage,there was no variance(x~2=2.387,P=0.122);the latency for the salivary gland change in treatment group was longer than that in control group(x~2=13.106,P=0.000).For the comparison of Karnofsky after radiotherapy,the KS was superior in the treatment group than that in control group(x~2=12.685,P=0.013);For the comparison of objective effect after radiotherapy,the remission rate in treatment group was 90 %,and it was 86.7 % in control group(x~2=0.638,P=0.727).Conclusion The decoction can remit the salivary gland response caused by radiotherapy in clinic,prolong the latency for acute radioactive response;release the pain of the pa- tients,increase the achievement ratio for radiotherapy,and improve the patients'living condition.To combine with radiotherapy,Chinese herbs is a good supplemental therapy for nasopharyngeal carcinoma

Background Channelrhodopsin-2 (ChR2)is a cation channel isolated from the eyespot of Chlamydomonas algae and has been used to control neuron activity.The light stimulation is a more precise fashion whether space or time than that of electrical,magnetic and ultrasound stimulation. Objective This study was to construct a replication deficient recombinant adenovirus cxpression vector of ChR2 and to determine its function.Methods Human embryo kidney 293 (HEK293) cell line was cultured and passaged in DF12 medium containing 10％ fetal bovine serum(FBS).The ChR2 gene was cloned at the downstream of cytomegalovirus(CMV)promoter of the adenoviral shuttle plasmid pSB291 in sense direction,and the resultant recombinant plasmid pSB291-hChR2- GFP was transfected into HEK293 cell together with plasmid pBHG lox ( deltaE1,3 ) containing adenoviral genome,then small amounts replication deficient recombinant adenovirus expression vector of ChR2 (Ad-ChR2) was obtained.Through amplification gradient centrifugation and dialysis,pure Ad-ChR2 was obtained.Visual cortex cells derived from 4 1-day-old clean Long Evans rats were primary cultured with serum-free culture media and infected by AdChR2.When expressing green fluorescencc,those cells received the stimulated of blue light with 460 nm.Patch clamp technique was applied to record an action potential. Results After purification and concentration,the titer of AdhCHR2 reached 7.9×1010 PFU/ml.Twenty-four hours after transfect of Ad-ChR2,HEK293 cell membrane showed the green fluorescence for the recombinant plasmid with green fluorescence protein under the inversed fluorescence microscope.The HEK293 cells change their shape from flat to round 13 days after transfected.The primary cultured visual cortex cells exhibited the green fluorescence 3-5 days after infected by Ad-ChR2.The action potentials evoked by blue light stimulation were recorded with patch clamp on those cells expressing green fluorescence. Conclusions Ad-ChR2 expressing vector is constructed successfully in this study.It is verified that Ad-ChR2 expressing vector can infect visual cortex cells with visual function.This result is very important for visual plasticity study.

OBJECTIVETo investigate the effect of rapid canine distalization through distraction of the periodontal ligament after reducing interseptal bone resistance.

METHODSTwenty canines in 11 patients who needed first premolar extractions were involved. A tooth-borne, custom-made distractor was bonded right after the first premolar extraction and the interseptal bone resistance reduction. Three days post-operatively, the distractor was activated 0.1 mm three times a day. Orthodontic models, panoramic radiographs, periapical radiographs, electrical vitality test were assessed pre- and post distraction procedure and 3 months after the completion of the procedure.

RESULTSThe distraction procedure was completed in 18 to 35 days [mean (25.6 +/- 4.7) days], with the distal displacement of the canines ranging from 3.53 to 8.29 mm [mean (5.56 +/- 1.32) mm]. The canines showed a mean of 12.20 degrees distal tipping and 18.53 degrees rotation. The anchorage teeth showed an average of (0.76 +/- 0.75) mm mesial movement. The mesial contact point of incisors showed a mean of (0.67 +/- 0.55) mm lingual movement. There was no significant root resorption or long-time change on pulp vitality after distraction.

CONCLUSIONSThe canine distalization through distraction of the periodontal ligament after reducing interseptal bone resistance was an effective approach to move canines rapidly.

Adolescent ; Cuspid ; surgery ; Female ; Humans ; Male ; Periodontal Ligament ; surgery ; Root Resorption ; surgery ; Tooth Movement Techniques ; methods

Objective: To find out the pathomechanism of low back and leg pain related to intervertebral disc. Methods: The nucleus pulposus of coccygeal vertebral was transplanted to the cavum epidurale of rats to establish the non-compressive model with transplanted nucleus pulposus. The evoke potentials and morphology of nerve roots were observed. Results: Even without mechanical compression, rats transplanted with nucleus pulposus resulted in significant harm to evoked potential and morphology of cauda equina. Conclusion: The biomechanical and/or immunologic inflammatory effect of nucleus pulposus can result in nerve roots injury and is an important factor in the pathogenesis of low back and leg pain.

The swallowable camera-capsule,described in the aper, 11 mm in diameter and 30 mm in length , contains a CMOS image sensor, an optical system, a battery, a light source, a transmitter, a antenna and so on. The CMOS image sensor and its driving circuit can be miniaturized with MEMS technology. Image signal can be transmitted by analog or digital way. Image signal can be wirelessly transmitted through serial data interface. Finally, the processing technics of the capsule's crust is introduced.
Capsule Endoscopes ; Equipment Design ; Wireless Technology

OBJECTIVETo develop a novel scaffolding method for the copolymers poly lactide-co-glycolide acid (PLGA) to construct a three-dimensional (3-D) scaffold and explore its biocompatibility through culturing Schwann cells (SCs) on it.

METHODSThe 3-D scaffolds were made by means of melt spinning, extension and weaving. The queueing discipline of the micro-channels were observed under a scanning electronic microscope (SEM).The sizes of the micropores and the factors of porosity were also measured. Sciatic nerves were harvested from 3-day-old Sprague Dawley (SD) rats for culture of SCs. SCs were separated, purified, and then implanted on PLGA scaffolds, gelatin sponge and poly-L-lysine (PLL)-coated tissue culture polystyrene (TCPS) were used as biomaterial and cell-supportive controls, respectively. The effect of PLGA on the adherence, proliferation and apoptosis of SCs were examined in vitro in comparison with gelatin sponge and TCPS.

RESULTSThe micro-channels arrayed in parallel manners, and the pore sizes of the channels were uniform. No significant difference was found in the activity of Schwann cells cultured on PLGA and those on TCPS (P larger than 0.05), and the DNA of PLGA scaffolds was not damaged.

CONCLUSIONThe 3-D scaffolds developed in this study have excellent structure and biocompatibility, which may be taken as a novel scaffold candidate for nerve-tissue engineering.

Animals ; Biocompatible Materials ; Cell Adhesion ; Cell Proliferation ; Cell Separation ; Cells, Cultured ; Lactic Acid ; Microscopy, Electron, Scanning ; Polyglycolic Acid ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; Tissue Engineering ; methods ; Tissue Scaffolds

OBJECTIVETo prepare a decellularized whole laryngeal scaffold by utilizing a perfusion-decellularized technique, reseed cells on it, and construct decellularized laryngeal muscles.

METHODSPerfusion decellularized larynxes were obtained by common carotid arterious perfusion with detergents. Then they were performed by macroscopic view, histological examination, scanning electron microscopy (SEM) and cartilage viability. Decellularized laryngeal scaffold were then reseeded with inducted mesenchymal stem cells (MSCs). Composites were transferred into greater omentums of rabbits after one day's adherence and harvested after eight weeks. Macroscopic view, histological examination and immunohistochemistry were performed.

RESULTSPerfusion larynxes became transparent after two hours. Histology and SEM indicated that perfusion method showed better decullularized effect. More vintages and collagen fibers but no intact cell or nuclei were retained in the decellularized matrix. Porosity measured by Image pro plus 6.0 was 80.4% +/- 3.2% (x +/- s). Chondrocyte vitality assay indicated chondrocyte vitality rate in the perfusion group was 86.9% +/- 1.5%. After eight weeks, vascularization formed and integrated cartilage frameworks still remained. Histological examination could clearly show the presence of muscle bundles and vessels. Immunohistochemical examination indicated that sarcomeric-alpha actin expressed positively in corresponding areas.

CONCLUSIONSIt is feasible to reseed MSCs into the decellularized laryngeal muscle matrix for constructing tissue-engineered laryngeal muscles. This in vivo maturation into the omentum could be the first step before in situ implantation of the construct.

Animals ; Extracellular Matrix ; Feasibility Studies ; Laryngeal Muscles ; cytology ; physiology ; Larynx, Artificial ; Rabbits ; Regeneration ; Tissue Engineering ; methods ; Tissue Scaffolds

BACKGROUNDFeatures of necrotic lesions and various interventions could affect the biomechanics of the femoral head. A three-dimensional finite-element analysis was designed to demonstrate necrotic femoral head stress changes with various sizes of necrotic lesions, and evaluate the effect of tantalum rods on preventing femoral head cracking.

METHODSFemoral computed tomography scans were used to build a normal three-dimensional finite-element femoral head model in a computer. Based on the normal model, necrotic models of different lesion diameters (15 mm, 20 mm and 30 mm) were created, as were the repaired models with tantalum rods for each diameter. After a series of meshing and force loading, the von Mises stress distributions, simulating single-legged stance, and stresses on specific points under loaded conditions were determined for each model.

RESULTSDeep exploration into the burdened area of the femoral head indicated that higher stresses to the femoral head were observed with a larger necrotic lesion; the largest stress concentration, 91.3 MPa, was found on the femoral head with a lesion diameter of 30 mm. By contrast, topical stress on the surface of the necrotic regions was lowered following implantation of a tantalum rod, and the changes in stress were significant in models with lesions of 15 mm and 30 mm in diameter, with the best biomechanical benefit from the tantalum rod found with a lesion diameter of 15 mm.

CONCLUSIONSFemoral heads with larger necrotic lesions usually have a higher stress concentration and a higher risk of collapse. Various sized lesions on the femoral head can benefit from the mechanical support offered by the implantation of a tantalum rod; however, femoral heads with smaller sized lesions may benefit more. A thorough evaluation of the lesion size should be conducted prior to the use of tantalum rod implants in the treatment of femoral head necrosis.

Femur Head ; physiology ; Femur Head Necrosis ; physiopathology ; Finite Element Analysis ; Humans ; Stress, Mechanical