BACKGROUND:Construction of tissue engineering adult cardiac myocytes has been a new research hotspot in cardiovascular fields.
OBJECTIVE:To explore a simple, fast method for the separation of adult rat cardiomyocytes, and preliminarily explore the construction methods of tissue engineering adult cardiac myocytes.
METHODS:Segmented enzymatic digestion method was used to isolate cardiac myocytes from adult rats. Subsequently, cardiac myocytes were transfected with adenovirus and liposome-mediated red fluorescent protein gene. Construction efficiency of tissue engineering cells was qualified using inverted fluorescence microscopy and flow cytometry. Final y, cardiac myocytes were transfected with adenovirus-mediated hypoxia-inducible factor-1a, and the expression of hypoxia-inducible factor-1a was examined by western blot analysis.
RESULTS AND CONCLUSION:A lot of cardiac myocytes were col ected using the segmented enzyme digestion method. Flow cytometric analysis showed that the survival of adult cardiomyocytes was (87.03±0.70)%. Compared with liposomal transfection (transfection efficiency was 0), adenovirus infection efficiency was (70.31± 1.39)%, and the cells expressed red fluorescence under fluorescence microscope. After 4 days of adenovirus infection, transfected cells expressed hypoxia-inducible factor-1a protein. These results showed that segmented enzyme digestion is a fast way to isolate adult cardiac myocytes, and recombinant adenovirus vector is a good vector to transfect cardiac myocytes.

Propionic acid, a major inhibitor to yeast cells, was accumulated during continuous ethanol fermentation from corn meal hydrolysate by the flocculating yeast under stillage backset conditions. Based on its inhibition mechanism in yeast cells, strategies were developed for alleviating this effect. Firstly, high temperature processes such as medium sterilization generated more propionic acid, which should be avoided. Propionic acid was reduced significantly during ethanol fermentation without medium sterilization, and concentrations of biomass and ethanol increased by 59.3% and 7.4%, respectively. Secondly, the running time of stillage backset should be controlled so that propionic acid accumulated would be lower than its half inhibition concentration IC50 (40 mmol/L). Finally, because low pH augmented propionic acid inhibition in yeast cells, a higher pH of 5.5 was validated to be suitable for ethanol fermentation under the stillage backset condition.
Biomass ; Ethanol ; metabolism ; Fermentation ; Flocculation ; Propionates ; chemistry ; Yeasts ; metabolism

The cGAS-STING pathway plays a significant role in host defense against viral and bacterial infection.In the process,the cytoplasmic free DNA,considered as a danger signal,is recognized by nucleotidyl transferase cGAS.cGAS is activated by double-stranded DNA (dsDNA) and catalyzes the synthesis of a noncanonical cyclic dinucleotide 2'5'-cGAMP from adenosine triphosphate (ATP) and guanosine triphosphate (GTP).cGAMP serve as an endogenous second messenger to stimulate the induction of type Ⅰ interferons via STING.In addition to the exogenous bacterial or viral DNA,abnormal deposition of host DNA in cytosol also activates the cGAS-STING signaling pathway cascade,resulting in inflammation and autoimmune diseases.Subsequent studies found that this pathway also plays an important role in tumor's responsiveness to radio-therapy and chemo-therapy.Activation of cGAS-STING pathway produces or enhances the therapeutic efficacy.These findings suggest that specifically interfering with cGAS-STING activation may hold therapeutic value for the treatment of cancer,infection and inflammatory diseases.In this paper,the activation mechanism of cGAS-STING pathway and its relationship with the treatment of diseases were summarized,and the regulation of cGAS-STING pathway was introduced in detail.

In recent years,Wnt/?-catenin signaling has been identified as a key player in embryogenesis and human diseases.Canonical Wnt signaling pathway is controlled by a variety of classic molecules like Wnt,?-catenin,Axin,APC,GSK-3? and CK1,which interact and coordinate to regulate the expressions of cell signaling molecules.The latest evidences suggest that some components of the Wnt/?-catenin signaling,like APC,GSK-3?,CK1,Dkk2 and WISE,play dual roles different from what they have been thought previously.Here we reviewed some recent discoveries on the canonical Wnt/?-catenin signaling pathway to provide some new ideas and principles for signaling transduction studies.

Chitosan, a linear polysaccharide, is obtained by chitin N deacetylation. Its ?(1 4) glucosidic bond is not stable and breaks easily in acid condition. In this study, chitosan of different molecular weights(MW) was prepared by acetic acid degradation. Chitosan was dissolved at 3%(w/v) concentration in 1%(v/v) acetic acid and the solution was dried at 50 degree C. We get chitosan membranes of different MW after neutralization with aqueous NaOH. The membranes are transparent, elastic and have good intensity. The permeability studies on chitosan membranes were going on with a permeable install made by our laboratory. It was determined by the transmission concentration of NaCl, L Tyr, glucose and calf albumin. We compared the permeability property with different MW chitosan membranes. The result implied that all of the four samples could permeate through the chitosan membranes. And the permeability property of the membrane increased with the chitosan MW decreaseing.

A1 strain with fibrinolytic activity was isolated from sea water in Qingdao. After combination treatment with ultraviolet light and MNNG, a mutant C22 producing 2947.60 u?mg -1 protein of fibrinolytic enzyme in culture broth was obtained.Its enzyme activity was 4.23 fold of wild stain A1.The optimum medium for fermentation consisted of 2.5% soy bean cake meal, 0.1% yeast extract,0.2%NaCl,0.05%MgSO 4?7H 2O,0.001%FeSO 4?7H 2O.They were dissolved with 0.05mol?L -1 ,pH7.4 phosphoric buffer.The strain producing maximum fibrnolytic activity after growth at 25℃ for 40h on a rotary shaker.The initial optimum pH was 7.0~7.5.

Objective:To construct the recombinant eukaryotic expression vector plasmids with mutant C-kit cDNA and to study the effect of the mutant C-kit gene on cell proliferation and cell cycle in gastrointestinal stromal tumor (GIST). Methods: Wild-type C-kit cDNA was cloned from human embryonic brain tissue by RT-PCR technique.Site-directed mutagenesis of the wild type C-kit cDNA was performed according to the C-kit mutations we cloned. Recombinant plasmids were stably transfected into human embryonic kidney cell line and the cells expressing mutant C-kit were selected by special cell culture medium containing G418.Expressions of C-kit protein of the transfectants were detected by Western blot.Cell proliferation and cell cycle of the transfectants were detected by MTT clolorimetic assay and flow cytometry,respectively.Whether HEK cell with mutated C-kit cDNA could grow autonomously in nude mice or not was also detected. pcDNA3 vector transfected and recombinant plasmids with wild-type C-kit cDNA transfected HEK cell were used as the control groups. Results: The mutant C-kit cDNA was obtained by site-directed mutagenesis of the wild type C-kit cDNA. Compared with the 2 control groups ,the growth rate and proliferative activity of the HEK cells with mutant C-kit cDNA were increased significantly.The analysis of cell cycle showed that more HEK cells with mutanted C-kit cDNA remained in proliferation phase (S+G 2-M)than the groups without mutated C-kit cDNA.HEK cells with the mutated C-kit also grew autonomously in nude mice.Conclusion: Mutation of C-kit gene can increase proliferation of human cells,causing malignant transformation of human normal cells,which may play an important role in the malignant transformation of GIST.

ACKGROUND: Adriamycin (ADM) can specifically conjugate with receptor. In particular, ADM nanopartides play a target role in decreasing the cytotoxicity.OBJECTIVE: To investigate the targeting effect of addamycin nanoparticles conjugated with hyaluronic acid (ADM-HA-SSL) on oral squamous carcinomas calls in vitro.DESIGN, TIME AND SETTING: An in vitro contrast observation was performed in College of Madne Life Science, Ocean University of China from January to July 2008. MATERIALS: Oral squamous carcinomas calls were sincerely presented by Professor Chen from the Ninth People's Hospital of Shanghai; ADM-HA-SSL (drug loading 156 mg/L) was sincerely presented by Professor Liu from College of Marine Life Science, Ocean University of Chine.METHODS: Oral squamous carcinomas cells were cultured with 0.5, 1.0, 5.0, and 10.0 mg/L ADM-HA-SSL. MTT assay was used to detect the targeted cytotoxicity of ADM-HA-SSL against oral squamous cell carcinomas. With the concentrations of 5.0 and 10.0 mg/L, call apoptosis was ascertained by call flow cytometry after 6, 12, 24 and 48 hours. MAIN OUTCOME MEASURES: Cell survival rate and apoptosis rate.RESULTS: At 24 and 48 hours after induction, cytotoxicity assay revealed that the effect of ADM-HA-SSL was superior to that of free ADM (t=5.78-42.05, P < 0.01). The results of flow cytometry showed that the apoptosis rate was enhanced with the increase of the time (F=4 200.40, 4 775.36, P < 0.01), and the rate was also increased at the same time point with the increase ofconcentration (t=12.06-20.08, P < 0.05).CONCLUSION: ADM-HA-SSL can specifically recognize oral squamous carcinomas cells and deliver adriamycin into the cells. And the effect is enhanced by the time prolonging.

Objective To design and implement a portable electrocardiogram (ECG) monitor for multiple users. Methods Multilevel menu on liquid crystal displayer(LCD) for switching among users based on digital signal processor(DSP) was developed. Record header in ECG records for different users was appended, and communication protocol between monitor and hospital center was made. Results This monitor could record three users’s ECG signal and transmit the ECG records to remote hospital center via digital communication method. The hospital center could receive and file the ECG records of different users. Conclusion This monitor can be used for three users and is more efficient in the application of ECG monitoring.

A simple,fast and highly sensitive fluorescence analysis method for detection of mercury ion was developed based on N-methyl-mesoporphyrin IX (NMM)/G-quadruplex DNA system and specific T-Hg-T mismatches.In this strategy,a large number of thymine was introduced into guanine-rich oigonucleotides which could form G-quadruplex.In the presence of Hg2+,guanine-rich oigonucleotides and complementary strand could form double-stranded DNA molecule by specific T-Hg-T mismatch pair,leading to destruction of G-quadruplex DNA structure.In the absence of Hg2+,guanine-rich oigonucleotides spontaneously formed G-quadruplex DNA structure that could bound NMM to generate intense fluorescence.Based on the above facts,a sensitive fluorescence biosensor for determination of Hg2+ was fabricated.And the optimal conditions for Hg2+ determination were as follows:buffer solution pH of 6.7,20 mmol/L KCl and 2.5 μmol/L NMM in buffer and incubation for 2 h.Under the optimal conditions,the fluorescence intensity signal change (F0-F) and the Hg2+ concentration exhibited a linear correlation within 50 nmol/L to 1000 nmol/L range with a low detection limit of 22.8 nmol/L (3σ).The biosensor exhibited good selectivity toward common metal ions.The developed method was successfully employed to detect Hg2+ in tap water with recovery of 106.1％-107.8％.