An effective technique for isolating adult activated Schwann cells

BACKGROUND： Schwann cells （SCs） are neuroglial cells of peripheral nerve and play a key role in repairing peripheral nerve injury; therefore, it provides an important evidence for transplantation of SCs which are characterized by active proliferation and adult high-purity in vitro after nerve injury in clinic, and also develops a new therapeutic way for nerve injury.OBJECTEVE： To investigate an effective technique for isolating adult activated Schwann cells,DESIGN： Controlled observational study.SETTING： Mudanjiang Medical College.MATERIALS： The experiment was completed at the Department of Medical Genetics of Harbin Medical University from March 2003 to April 2005. Health female Wistar rats, aged 2 months, weighting 150-160 g, were randomly divided into 3 groups with 5 in each group.METHODS： The right sciatic nerves from 15 Wistar rats were exposed and transected at the mid thigh under pentobarbital anesthesia （4 mg/kg, Lp）. Seven days later, the distal segments of the predegenerated nerves were removed and used to produce adult Schwann cell cultures. The distal segment of the predegenerated nerve, 20 mm in length, was resected. The nerve was cut into pieces 1 mm in length and incubated for 3 hours under CO2 at 37 ℃ with an enzyme mixture of 0.05% collagenase/dispase. Rats were divided into 3 groups： ① Group 1： The nerve fragments were explanted in poly-L-lysine and laminin-coated dishes with BS medium from the 1st to the 6th day, On the 6^th day, the fragments were removed into a new poly-L-lysine-laminin-coated dish and the BS medium was changed to BS with 10% FBS, The nerve fragments were replaced repeatedly in the same way in new dishes on the 12^th and the 18th days. ② Group 2： For the first 3 days, the nerve fragments were fed with BS with 10% FBS. This medium was changed to BS medium on the third day. The nerve fragments were removed to another dish on day 6 and BS medium was changed to BS with 25 mI.JL FBS. Hereafter the culture method was the same as for group 1. ③ Group 3： For the first 6 days, nerve fragments were incubated in a dish not coated with poly-L-lysine and laminin, in BS medium supplemented with 8×10^7 U/L of penicillin-streptomycin. On the 6th day, the nerve fragments were removed to a poly-L-lysine-laminin-coated dish and cultured in BS with 25 mI.JL FBS, On the 12th day, the nerve fragments were explanted a second dish and fed with BS containing 100 mL/L FBS. On the 18^th day, they were explanted to a third poly-L-lysine-laminin-coated dish, SCs were obtained from all 3 dishes on the 21st day, Finally, purity and density of SCs were identified and proliferation index was calculated at the same time.MAIN OUTCOME MEASURES ： Purity and density of SCs cultured with various methods in the three groups for 21 days.RESULTS ： ① Isolation and proliferation of SCs： In the group 1, they increased in number after 4 days and both purity and density of cultured SCs were significantly higher than those from group 2. In the group 2, there were few fibroblasts. In the group 3, both purity and density of cultured SCs were remarkably higher than in those from groups 1 or 2. Then optimal proliferation was soon seen and the rapid expansion of SC populations suppressed the development of contaminating fibroblasts. On the 21st day, SCs proliferated to achieve maximal density and were too crowded to be counted. With Chi-square test, the data of the purity and the density were analyzed from groups 1 to 3, the result indicated X^2=430.47, P 〈 0.05. ② Characterization and proliferation rate of SCs： Immunostaining for S100 protein was evident in the cell soma and the processes of all three groups in cultures of SCs. SCs in vitro demonstrated typical bior tri-polar morphology, had oval nuclei, and stained brightly for $100. The proliferation rate of SCs was assessed with double fluorescence staining for BrdU and S100 on the 21^st day of all three groups in cultures. About 40%-50% of the total SCs in the each group showed BrdU incorporation.CONCLUSION： The method is to use predegeneration in vivo, differential speed culture supplemented with the penicillin-streptomycin in low concentration, and changing of the concentration of FBS in the BS medium from 0 to 100 mL/L. This method allows remarkable suppression of fibroblast growth and attainment of SC proliferation and purity, in a short time, from adult nerves.

Comparison of brain functions between healthy participants and methamphetamine users with various addiction histories:Data analysis based on EEG and fNIRS

The electroencephalogram(EEG)rhythm and functional near-infrared spectroscopy(fNIRS)activation levels have not been compared between a healthy control group(HCG)and methamphetamine user group(MUG)with different addiction histories.This study used 64-electrode EEG and fNIRS to conduct an experiment that analyzed the resting and craving states.The EEG and fNIRS data of 56 participants were collected,including 14 healthy participants,14 methamphetamine users with an addiction history of 0.5–5 years,14 users with an addiction history of 5–10 years,and 14 users with an addiction history of 10–15 years.Isolated effective coherence(iCoh)within the brain network was used to process the EEG data.Statistical analysis was performed to compare differences in iCoh among the delta,theta,alpha,beta,and gamma bands and explore oxyhemoglobin activation levels in the ventrolateral prefrontal cortex,dorsolateral prefrontal cortex,orbitofrontal cortex,and frontopolar prefrontal cortex(FPC)of the control group.Finally,the Kmeans,Gaussian mixed model(GMM),linear discriminant analysis(LDA),support vector machine(SVM),Bayes,and convolutional neural networks(CNN)algorithms were used to classify methamphetamine users based on drug and neutral images.A 3-class accuracy was achieved.Changes in EEG and fNIRS activation levels of HCG and MUG with varied addiction histories were demonstrated.

Total ionizing dose effect in an input/output device for flash memory

Input/output devices for flash memory are exposed to gamma ray irradiation. Total ionizing dose has been shown great influence on characteristic degradation of transistors with different sizes. In this paper, we observed a larger increase of off-state leakage in the short channel device than in long one. However, a larger threshold voltage shift is observed for the narrow width device than for the wide one, which is well known as the radiation induced narrow channel effect. The radiation induced charge in the shallow trench isolation oxide influences the electric field of the narrow channel device. Also, the drain bias dependence of the off-state leakage after irradiation is observed, which is called the radiation enhanced drain induced barrier lowing effect. Finally, we found that substrate bias voltage can suppress the off-state leakage, while leading to more obvious hump effect.

Effects of Cadmium on the Energy Metabolism of Isolated Hepatocytes: Its Relationship with the Nonviability of Isolated Hepatocytes Caused by Cadmium

The effects of cadmium on the energy metabolism of mitochondria were studied with isolated hepatocytes and rat liver mitochondria. It was found that cadmium inhibited the respiration of both isolated hepatocytes and mitochondria and decreased the ATP content of isolated hepatocytes. This inhibition of energy metabolism of mitochondria was highly related to the nonviability of isolated hepatocytes caused by cadmium. The site of electron transport of the mitochondrial respiratory chain blocked by cadmium was located between cytochrome b and flavoproteins. The uncoupling effects of mitochondrial oxidative phosphorylation caused by cadmium may have resulted from changes in the fluidity and permeability of the mitochondrial membrane. (c) 1990 Academic Press. Inc.

IN VITRO ANTI-HEPATOMA EFFECTS OF MONOCYTES AND KUPFFER CELLS ISOLATED FROM HEPATOMA PATIENTS AFTER TREATMENT WITH BIOLOGICAL IMMUNE STIMULANTS

Monocytes (MC), lymphocytes (LC) and Kupffer cells (KC) were isolated respectively from blood and surgical liver samples of patients suffering from he-patocellular carcinoma (HCC). 13 patients were given BCG, mixed bacterium vaccine (MBV) and human white blood cell interferon (IFN), the other 3 patients were not treated with any biological immune stimulants (BIS) and served as controls. The cytosta-tic and cytotoxic effects of MC and KC on human hepatoma SMMC-7721 (TC) were assayed in vitro and the numbers of T total (Tt), T helper (Th) and T suppressor (Ts) cells were counted using CD monoclonal antibody immunofluorescence. The results were as follows: (1) On the 7th day after the first administration of BIS, the cytostatic and cytotoxic effects of MC on TC showed obvious increase over pre-administration. The activity of BIS was 1 ?5 times as high as that in the controls. (2) After 3 administrations, the cytostatic effect of MC on TC increased to the normal level (84%), while the controls remained as before (45%). (3) On the 7th day after first administration, cytostatic and cytotoxic effects of KC on TC were 0.5 and 1 times higher respectively than those of the controls. (4) The numbers of Tt and Th of patients given BIS increased continuously; on the contrary Ts decreased in number. These results indicate that combined use of BCG, MBV and IFN can actively enhance the immune anti-hepatoma function of patients suffering from HCC.

Protective effects of levosimendan and ulinastain on the isolated rabbit heart

Objective Levosimendan,a new calcium ion sensitizer,is currently used in the treatment of heart failure and as an option for patients with injury to the left heart or at high risk for surgery. The study tried to evaluate the effects of levosimendan and ulinastain for protecting myocardium from ischemia-reperfusion (I / R) injury to

Suppressing interfacial side reactions of zinc metal anode via isolation effect toward high-performance aqueous zinc-ion batteries

Aqueous zinc(Zn)-ion batteries(AZIBs)are one of the most promising large-scale energy storage devices because of the excellent features of zinc metal anodes,including high theoretical capacity(5,855 mAh·cm^(–3)and 820 mAh·g^(−1)),high safety,and natural abundance.Nevertheless,the large-scale applications of AZIBs are mainly limited by the severe interfacial side reactions of zinc metal anodes,which results in low plating/stripping Coulombic efficiency and poor cycling stability.To address this issue,we report an artificial Ta_(2)O_(5)protective layer on zinc foil(Ta_(2)O_(5)@Zn)for suppressing side reactions during Zn deposition/stripping.The results of density functional theory calculation and experiments indicate that Ta_(2)O_(5)@Zn anode can inhibit the side reactions between the electrolyte and zinc anode through the isolation effect.Benefiting from this advantage,the symmetric cells with Ta_(2)O_(5)@Zn anode delivered an ultralong lifespan of 3,000 h with a low overpotential at 0.25 mA·cm^(−2)for 0.05 mAh·cm^(−2).Furthermore,the full cells consisting of Ta_(2)O_(5)@Zn anode and MnO_(2)or NH_(4)V_(4)O_(10)cathode all present outstanding electrochemical performance,indicating its high reliability in practical applications.This strategy brings new opportunities for the future development of rechargeable AZIBs.

Attribution of explanatory factors for change in soil organic carbon density in the native grasslands of Inner Mongolia,China

The variation in soil organic carbon density（SOCD） has been widely documented at various spatial and temporal scales. However, an accurate method for examining the attribution of explanatory factors for change in SOCD is still lacking. This study aims to attribute and quantify the key climatic factors, anthropogenic activities, and soil properties associated with SOCD change in the native grasslands of Inner Mongolia, China, by comparing data between the 1960s and the 2010s. In 2007 and 2011, we resampled 142 soil profiles which were originally sampled during 1963–1964 in the native grasslands of Inner Mongolia. SOCD was determined in A horizon（eluvial horizon） of the soil. We selected the explanatory factors based on a random forest method, and explored the relationships between SOCD change and each of the explanatory factors using a linear mixed model. Our results indicated that the change in SOCD varied from the east to the west of Inner Mongolia, and SOCD was 18% lower in the 2010s than in the 1960s. The lower SOCD in the 2010s may primarily be attributed to the increasing in mean annual water surface evaporation, which explained approximately 10% and 50% of the total variation and explainable variation in the change in SOCD, respectively. The sand content of the soil is also a significant explanatory factor for the decrease in SOCD, which explained about 4% and 21% of the total variation and explainable variation in the change in SOCD, respectively. Furthermore, the collection of quantitative information on grazing frequency and duration may also help to improve our understanding of the anthropogenic factors that govern the change in SOCD.

Effective Isolation of Retrotransposons and Repetitive DNA Families from the Wheat Genome

New classes of repetitive DNA elements were effectively identified by isolating small fragments of the elements from the wheat genome. A wheat A genome library was constructed from Triticum monococcum by degenerate cleavage with EcoO1091, the recognition sites of which consisted of 5＇-PuGGNCCPy-3＇ multi-sequences. Three novel repetitive sequences pTm6, pTm69 and pTm58 derived from the A genome were screened and tested for high copy number using a blotting approach, pTm6 showed identity with integrase domains of the barley Tyl-Copia-retrotransposon BARE-1 and pTm58 showed similarity to the barley Ty3-gypsy-like retrotransposon Romani. pTm69, however, constituted a tandem array with useful genomic specificities, but did not share any identity with known repetitive elements. This study also sought to isolate wheat D-genome-specific repetitive elements regardless of the level of methylation, by genomic subtraction. Total genomic DNA of Aegilops tauschii was cleaved into short fragments with a methylation-insensitive 4 bp cutter, Mbol, and then common DNA sequences between Ae. tauschii and Triticum turgidum were subtracted by annealing with excess T. turgidum genomic DNA. The D genome repetitive sequence pAt1 was isolated and used to identify an additional novel repetitive sequence family from wheat bacterial artificial chromosomes with a size range of 1 395-1 850 bp. The methods successfully led pathfinding of two unique repetitive families.

Failure behavior analysis of phased-mission systems considering functional and physical isolation effects

Phased-Mission Systems(PMS)are widely applied in aerospace,telecommunication and intelligent systems for multiple,consecutive and non-overlapping phases of missions.The phasedependent stresses and system structure cause some difficulties to the reliability analysis of PMSs.In this paper,we analyze the physical isolation effects on the degradation speeds and across-phase damage accumulations of failure mechanisms.And,some corresponding reliability and unreliability formulas are derived.Besides,a hierarchical Binary Decision Diagram(BDD)-based modeling method is proposed for incorporating functional and physical isolation effects into BDD models,and the analytical method with phase algebras is introduced for studying the failure behavior of PMS with functional dependence.In the case study,we evaluate the collision avoidance system of a fixed-wing unmanned aerial vehicle as an example to demonstrate the proposed modeling and analysis method.Results show that the physical isolation effects have significant influences on the degradations of components,which deserves detailed analysis for a more practical and realistic PMS’s failure behavior.

MEDICINAL PLANTS OF THE GENUS LEONURUS AND SEVENTEEN OF THEIR ISOLATED CONSTITUENTS SCREENED FOR EFFECTS ON PPARa,β/δ, and γ IN AN IN VITRO LUCIFERASE REPORTER GENE ASSAY

Leonurus japonicus Houtt.is used in TCM to treat the metabolic syndrome.However,up to now,no active constituents could be identified.Here we describe the isolation of 17 dominant constituents of L.japonicus and the related European herb Leonurus cardiaca L.-namely7R-chloro-6-desoxy-harpagide,ajugol,campneoside II,chicoric acid,ferulic acid,harpagide,isoacteoside,