Mechanical force has essential effects on cellular behaviors such as proliferation, migration and differentiation, and the mechanism of mechanotransduction is still one of the hot spots in mechanobiology study. Traditional methods could not provide accurate evaluation of the protein activation signal upon mechanical stress application. The development of fluorescence protein technology greatly promoted the understanding of mechanotransduction. In particular, genetically-encoded biosensors based on fluorescence resonance energy transfer (FRET) technique has achieved a real-time dynamic observation of living cell signal protein activity, which provides a powerful tool for the in-depth study of biomechanics. In this paper, we provide a summary on recent progress of FRET application in biomechanics. Firstly we introduce the FRET technology, and then we summarize three methods to integrate the mechanical stimulation with the FRET imaging system on cell experiments. After that, the important progress of biomechanical research on signal pathway made by FRET technology, such as cytoskeleton, Rho family, calcium and cellular physical stress visualization, are also discussed. Finally, we point out the bottleneck of the future development in FRET technology, and also make the prospect of the application of FRET in mechanotransduction. In summary, FRET technology provides a powerful tool for the studies of mechanotransduction, which will advance our systematic understanding on the molecular mechanisms about how cells respond to mechanical stimulation.
Biomechanical Phenomena ; Biosensing Techniques ; Fluorescence Resonance Energy Transfer ; Humans ; Luminescent Proteins ; chemistry ; Mechanotransduction, Cellular ; Microscopy, Fluorescence ; Signal Transduction ; Stress, Mechanical

Cardiac arrest (CA) is an acute critical illness with the high occurrence in the world. The directions of cardiopulmonary resuscitation (CPR) development are to improve CA patients' survival rate and to decrease the poor prognosis. β-blockers can selectively block the neurotransmitter or receptor agonists. They offer beneficial pharmacological properties and have been widely used in the treatment of cardiovascular diseases. Based on the search result of the domestic and foreign medical databases, the usage of β-blockers including clinical research, animal experiments and clinical work of CPR patients was summarized. Finally, the CPR research progress of β-blockers in recent years was reviewed in the article.

Objectives: To evaluate the effects of glutamine on the nutritional metabolism and permeability of intestinal mucosa in MODS patients.Methods: The randomized and controlled study was designed.Twenty MODS patients were randomly divided into control group and treatment group.The concentration of serum albumin,transferrin and blood sugar,L(lactulose) and M(mannitol) ratio in urine,nitrogen balance,the related complication were compared and obserwed.Results: In treatment group,the concentration of serum albumin,prealbumin and transferrin were higher than that of control group on the same time and showed significant difference(P

Objective To study the fatal risk factors to the patients with sepsis.Methods The data of 49 patients with sepsis were analyzed,who were consecutively admitted to intensive care unit(ICU)of Peking Union Medical College Hospital within six months.Patients' general states,clinical information,human leucocyte antigen-DR(HLA-DR)in blood monocytes and plasma level of diamine oxidase(DAO)were recorded.Simple logistic regression was done to analyze all the risk factors,and statistically significant variables were selected and used in multivariate and unconditioned Logistic regression analysis.The primary end point was hospital mortality.Results The subjects involved in present study were consisted of 49 patients with sepsis admitted to ICU of the Peking Union Medical College Hospital from Aug.2003 to Jan.2004,averagely aged 60.8?16.9 years;including 32 males(65.3%)and 17 females(34.7%);with APACHEⅡscores 18.6?8.0 and SOFA scores 5.9?3.8.Twenty-one out of the 49 patients(42.9%)were from non-operation department,and the other 28 patients(57.1%)were from operation department.ICU duration was 14.4?12.8 days;eighteen of the 49 septic patients died during hospitalization,with the 28-days mortality of 36.7%.Positive blood cultures(OR=5.237,95%CI 1.041~26.34,P=0.045),decreased platelet count and blood HLA-DR(OR=0.943,95%CI 0.901~0.98,P=0.01),and increased plasma levels of DAO(OR=2.235,95%CI 1.101~4.53,P=0.026)were obviously associated with mortality.The positive blood cultures,decreased blood HLA-DR and increased plasma levels of DAO were independent fatal risk factors for the patients with sepsis.Conclusions The positive blood cultures,decreased blood HLA-DR and increased plasma levels of DAO are high risk for the patients with sepsis at admission.

Objective To investigate the methods for the detection of serum samples with low-concentration HBsAg and its clin-ical value.Methods Serum samples with HBsAg weak positive were measured by ELISA or using Roch cobas e601 were collected from the clinical laboratory.The samples with low-concentration HBsAg were confirmed by neutralization assay by using Lizhu ELISA reagent Kit or Roch cobas e601 analyzer.at the same time,ALT/AST concentrations and HBV DNA copies were also deter-mined.Results Among 53 samples that showed weak positive reaction by using Kehua reagent kit,37 samples were positive in neu-tralization test,while the other 16 samples were negative.Among 18 samples that showed weak positive reaction tested by using Roch cobas e601 analyzer,13 samples showed positive in neutralization test,and the other 5 samples showed negative.Conclusion The results of HBsAg test varies in different detection System.The clinical significance of samples with low-concentration HBsAg needs further study.

Objective:To explore the anti-fatigue effect of Tibet maca in mice. Methods: The mice were respectively given the powder or the alcohol extract of Tibet maca. The lactic acid concentration in blood, serum lactate dehydrogenase ( LDH) , the time of weight loading swimming and serum urea ammonia level after the exercise in the mice were detected, and the anti-fatigue effect of the powder and the alcohol extract of Tibet maca was compared. Results: After the 30-day feeding, the serum LDH activity of the mice taking the powder or alcohol extract of Tibet maca was obviously higher than that of the mice in the control group(P<0. 05), the time of weight loading swimming was significantly longer than that in the control group (P<0. 05), and the blood lactic acid concentration after the exercise was obviously lower than that in the control group (P<0. 05). Conclusion: Tibet maca can improve the time of weight loading swimming of mice, and reduce the level of serum urea ammonia after exercise and blood lactic acid concentration, sug-gesting the powder and alcohol extract of Tibet maca have obvious anti-fatigue effect.

Objective To investigate the clinical advantages and safety profile of the combinational treatment of acute progressive cerebral infarction with aspirin,clopedogrel and atorvastatin.Methods 170 cases with acute progressive cerebral infarction were randomly divided into the treatment group and control group,85 patients in each group.Both two groups were initially treated with aspirin and atorvastatin.After excluding the possibility of hemorrhage, the treatment group additionally received clopedogrel,while the control group was treated with aspirin and atorvastatin. The difference in clinical efficacy was evaluated between before treatment and 7 days,14 days or 28 days after treatment by using the NIH Stroke Scale (NIHSS)and Barthel Index (BI).Results The NIHSS scores of the treatment group after 7d,14d and 28d were (12.52 ±3.25)points,(9.10 ±3.21)points and (6.87 ±2.85)points, which of the control group were (13.65 ±2.93)points,(10.73 ±3.41)points and (9.07 ±2.96)points respectively, the differences between the two groups were statistically significant(t =2.340,3.170,4.877,all P <0.05).The BI scores of the treatment group after 7d,14d and 28d were (35.26 ±11.18),(53.73 ±13.74)and (74.61 ±17.35), which of the control group were (31.98 ±9.12),(46.65 ±11.79 )and (63.87 ±15.73 )respectively,the differences between the two groups were statistically significant(t =2.131,3.752,4.456,all P <0.05).The overall effective rates of the treatment group after 7d,14d and 28d were 62.7%,79.5% and 94.0%,which of the control group were 51.2%,68.3% and 84.1% respectively.The differences of overall effective rates were statistically significant after 14d and 28d(χ2 =4.711,8.531,all P <0.05).Few reverse reactions were observed in both two groups.Conclusion Compared with the aspirin and atorvastatin therapy,combinational treatment of acute progressive cerebral infarction together with clopedogrel has a better efficacy,safety profile and significant promotion on neurological recovery.

Paraneoplastic neurological syndromes (PNS) were defined as neurological syndromes associated with cancer.In many cases,autoantibodies against neural antigens expressed by the tumor (paraneoplastic neurological antibody or onconeural antibodies) were detected.The neuronal antibodies,which were associated with syndromes resulting from central nervous system neuronal dysfunction,were classified into two groups according to the location of the antigen:inside the neuron or in the cell membrane.Group Ⅰ antibodies targeted on intracellular antigens and were predominantly dependent on T-cell-mediated responses.Group Ⅱ antibodies recognized neuronal surface antigens and were predominantly dependent on B-cell-mediated responses.Onconeural antibodies were useful diagnostic markers of the brain disease,and in some cases,they might reveal an underlying malignancy.Moreover,the presence of antibodies against surface(group Ⅱ) antigens might predict a more favorable response to immunotherapy than that against intracellular (group Ⅰ) antigens.

Humans typically have 22 pairs of autosomal chromosomes in cells,and a pair of sex chromosomes.Some individuals have an extra,autosomal chromosome called a small supernumerary marker chromosome (sSMC).sSMC is a structurally abnormal chromosome fragment.The fragments are too small and no-specific banding pattern to be identified by conventional banding cytogenetic analysis.Array-based comparative genomic hybridization (aCGH),fluorescence in situ hybridization (FISH) or other molecular biological methods are necessary for the diagnosis.This article summarized the karyotype,pathogenesis,and the clinical manifestations of the sSMC-related chromosome 18p abnormalities.The patients with sSMC usually presented with abnormal chromosome syndrome.Some syndromes are relative common,such as Pallister-Killian syndrome,isochromosome 18p syndrome,Cat eye syndromes or Emanuel syndrome.sSMC is considered to be the frequent cause of mental retardation.The patients have no specific symptoms.With the progress of molecular cytogenetics,more sSMC has been identified.Genetic counseling and prenatal diagnosis are important to prevent sSMC.Molecular cytogenetic techniques are necessary to the diagnosis.

Biliary tract cancer (BTC)is one of the most aggressive malignancies with only 1 0% early-stage diagnosis rate.For advanced BTC,regimen of gemcitabine and cisplatin has been regarded as the first line standard combination,but the curative effect is still unsatisfied.Infiltration of immune cells and immune-related microenvironment can inhibit various types of cancers.In BTC,higher frequencies of tumor-infiltrating CD8 + cytotoxic T cells and CD4 + T cells are closely associated with favorable prognosis.These findings have provided the rationale for further development of immunotherapies as a novel treatment modality against BTC.