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Cell biology experiments in space are indispensable for investigating the effects of microgravity environment on living organisms. As an important technological means of supporting life science researche, space cell bioreactor may directly influence the data quality of space cell biology experiments and research level. To date, space cell bioreactor techniques are still under development, and lack of standard rationale. In this article, the technical progresses of space cell bioreactor were reviewed, by introducing the operational principle of several typical space cell bioreactors, analyzing the mode of culture medium supplying and character of fluid mechanics environment in space, as well as the relevant supporting techniques about the parametric controlling on temperature, dissolved oxygen and pH value and on-line microscopic imaging, so as to discuss the future perspective about space cell bioreactor techniques.
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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.
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Objective To detect the recruitment pattern of motor unit in human flexor digitorum superficialis (FDS) at different force levels produced by the index finger. Methods Eight subjects were recruited to produce a certain force level with the index finger to match the ordered force level (20%, 40%, 60% maximum voluntary contraction). During the force tracking task, the multi-channel surface electromyography (sEMG) signals were recorded on FDS using 8×1 (row×column) electrode-array. The motor unit action potential (MUAP) information was extracted by Fast Independent Component Analysis (FastICA), and then the correlation between MUAP pattern and force level was analyzed. Results Four different types of MUAP were extracted successfully by FastICA from original sEMG signals and the total number of MUAP showed an increasing trend with the force level increasing. At different force levels, the proportion of different types of MUAP was different, showing different trends with change of the force level. ConclusionsAt different levels of the finger force, the recruitment pattern of motor unit in FDS will be changed so as to produce the force accordingly.
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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.
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<p><b>BACKGROUND</b>A patented remote controlled capsule (RCC) has recently been developed to provide noninvasive drug delivery to selected sites in the human gut that allows assessment of regional gastrointestinal (GI) drug absorption under a normal physiological environment. The objective of this study was to investigate the rate and extent of aminophylline absorption after site-specific delivery of the drug in the GI tract using RCC and a magnetic marker monitoring (MMM) technique.</p><p><b>METHODS</b>This study was conducted in twelve healthy male subjects, in a three-treatment, randomized, crossover manner with a 7-day washout. Eligible subjects received a 150 mg aminophylline dose through an oral administration, or via a remote controlled capsule, delivered to the small bowel or ascending colon. MMM was employed to monitor the GI transit of the RCC, and the radio-frequency signal was used to activate capsules at target sites. Blood samples were obtained at regular intervals until 24 hours post dose/activation. Plasma theophylline concentrations were measured by a TDx System Analyzer. A comparison of the PK profile with the oral dosing route of aminophylline was performed after delivery to the small bowel and colon.</p><p><b>RESULTS</b>The RCC was well tolerated in volunteers. The mean capsule activation time for the small bowel and ascending colon was 2.07 hours and 6.08 hours post dose. Aminophylline had similar absorption profiles from the small bowel compared with the stomach, with an area under the curve (AUC(t)) ratio of 92% vs. the stomach, but a lower absorption profile from the ascending colon, with an AUC(t) ratio of 47.2% vs. the stomach.</p><p><b>CONCLUSIONS</b>The proprietary of the RCC and MMM technique offer the opportunity to obtain data on the intestinal absorption of a drug in humans under noninvasive conditions. Aminophylline is rapidly and efficiently absorbed from the small bowel. While colonic absorption was limited by the poor water condition although effective absorption was observed from the ascending colon. This provides an opportunity for rational development of modified-release formulations as well as alternative dosage forms.</p>
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Adult , Humans , Male , Young Adult , Aminophylline , Pharmacokinetics , Capsules , Pharmacokinetics , Colon , Metabolism , Intestine, Small , MetabolismABSTRACT
Objective To explore the effect of gene mutations of arsenic transport proteins-muhidrug resistance-associated proteins(MRP1 and MRP2)on phenotype of endemic arsenic poisoning.Methods Two hundreds and thirty-nine rural residents in 3 villages of Shuocheng Region,Shanxi Province were interviewed and examined by simple random sampling who had been lived there for 20 yearn at least.All the objects were divided into two groups on the basis of clinical examination with"The Standard Diagnosis of Endemic Arsenic Poisoning" (WT/S 211-2001):subjectives with skin lesion as a arsenic poisoning group and without skin lesion as a control group. One hundred and ninety-three blood samples were collected from each participanL Seventy-five arsenic poisoning cases and 118 controls were detected the gene mutations in the 2,17,23 exons of M RPI and the 10,18,31 exons of MRP2 by PCR-single strand conformation polymorphism (PCR-SSCP) and compared by multivariate Logistic regression model. Results Seventy-five cases and 164 controls underwent questionnaires. Age[ (58.85±11.26) vs (45.73±11.92),OR = 3.378,P ＜ 0.05],gender[male,57.3%(43/75)vs 27.4%(45/164),OR = 3.553,P＜ 0.01 ],smoking[46.7%(35/75) vs 21.3%(35/164),OR = 3.225,P ＜ 0.01 ],drinking[ 17.3%(13/75) vs 8.5% (14/164),OR = 1.836,P ＞ 0.05],vegetable and fruit intake[5.3%(4/75) vs 9.1%(15/164),OR = 0.560,P ＞ 0.05],egg and meat intake[34.7%(26/75) vs 30.5%(50/164),OR = 1.210,P ＞ 0.05],exposure of pesticide [41.3%(31/75) vs 29.3%(48/164),OR = 1.864,P ＜ 0.05] were tested by Logistic regression model. There was no gene mutation detected in the 23 exon of MRP1 and the 18 exon of MRP2. The gene mutations frequencies of the 2 exons of MRP1 in arsenic poisoning and control groups were 8.00% (6/75) and 5.93% (7/118),respectively;they were 13.33%(10/75) and 8.47%(10/118) of the 17 exons of MRP1,respectively;they were 22.67%(17/75) and 18.64%(22/118) of the 10 exons of MRP2,respectively;they were 5.33%(4/75) and 2.54%(3/118) of the 31 exons of MRP2,respectively. There was no significant difference between two groups(x2 = 0.312,1.165,0.460, 2.794,respectively,all P ＞ 0.05). After age,gender,smoking,drinking,nutritional level and exposure of pesticide being adjusted by multivariate Logistic regression model,there was no significant difference between two groups (OR = 0.803,1.892,2.388,1.098,respectively,all P ＞ 0.05). Conclusions The gene mutations of 2,17,23 exons of MRPI and the 10,18,31 exons of MRP2 may have no effect on the phenotype of endemic arsenic poisoning.
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<p><b>OBJECTIVE</b>To investigate the role of multidrug resistant protein 2 (MRP2) and glutathione (GSH) cotransport system in hepatic arsenic metabolism in rats.</p><p><b>METHODS</b>Thirty healthy Wistar rats were divided randomizedly into five groups. The first group was the control group and the rats in this group were administered with normal saline. In the second, third and fourth group the rats were administered with 4, 10 and 20 mg As(+)3/kg BW of sodium arsenite respectively every other day for two weeks. The fifth group was the benzene-soluble organics (BSO) intervention group and in this group the rats were administered with 2 mmol/kg BW BSO intraperitoneally every day three days before the end of the experiment. The other treatment was the same as in other groups. All rats were sacrificed two weeks after the treatments. Arsenic contents in bile, liver and blood were detected by atomic absorption spectroscopy (AAS), and the expression of MRP2 in the membrane of hepatocyte was determined by Western-blot analysis.</p><p><b>RESULTS</b>The level of total arsenic (including organic arsenic and inorganic arsenic) in bile, liver and blood in all three different dose groups was higher than those in the control groups (P < 0.05). Arsenic levels of bile and liver were increased with intragastric arsenic dose. Blood arsenic levels were not significantly different in three different dose groups. Expression of hepatic MRP2 was increased with intragastric arsenic concentration. A positive correlation between biliary arsenic concentration and MRP2 levels was found in liver (r = 0.986, P < 0.05). For the rats pretreated with BSO, the biliary arsenic was significantly higher than that in the control group but lower than that in the high dose group; the liver and blood arsenic was higher than that in the control group and in the high dose group. Expression of MRP2 pretreated with BSO was decreased.</p><p><b>CONCLUSION</b>Sodium arsenite can induce expression of MRP2 and the up-regulation of MRP2 may play an important role in the bile secretion of arsenite and its metabolites. The function of MRP2 for transportation of arsenic and its metabolites is associated with the intracellular GSH level. BSO inhibits the synthesis of GSH, which weakens the function of the MRP2-GSH cotransport system and makes the liver arsenic increased.</p>
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Animals , Female , Male , Rats , Arsenic , Pharmacokinetics , Arsenic Poisoning , Metabolism , Bile , Metabolism , Glutathione , Liver , Metabolism , Membrane Transport Proteins , Multidrug Resistance-Associated Proteins , Random Allocation , Up-RegulationABSTRACT
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.
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Capsules , Computer Simulation , Drug Delivery Systems , Methods , Equipment Design , Infusion Pumps, Implantable , Technology, Pharmaceutical , MethodsABSTRACT
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.