Biomedical subjects

Bo Yao

Publications and source records attributed to Bo Yao.

At least 19 recordsLinked to original sources

PubMed2026

Transketolase promotes RNF20-dependent H2BK120 ubiquitination and DNA repair through a non-enzymatic adaptor function.

Efficient repair of DNA double-strand breaks (DSBs) is essential for maintaining genome stability and conferring tumor radioresistance. Histone H2B monoubiquitination at lysine 120 (H2BK120ub), catalyzed by the RNF20/RNF40 E3 ligase complex, promotes DSB repair by coordinating chromatin remodeling and repair factor recruitment. Here we identify transketolase (TKT) as a non-enzymatic regulator of DNA damage repair in colorectal cancer cells. TKT enhances DNA repair efficiency and radioresistance independently of its catalytic activity by facilitating RNF20-dependent H2BK120ub. Mechanistically, TKT interacts with both the RNF20/RNF40 complex and the FACT chromatin remodeling complex, functioning as a non-enzymatic adaptor that facilitates FACT-RNF20 association and RNF20 foci formation following DNA damage. Disruption of this TKT-FACT-RNF20 axis impairs RNF20 foci formation and H2BK120ub induction, increases DNA damage, and enhances radiosensitivity. These findings reveal a previously unrecognized non-enzymatic adaptor function of TKT in DNA damage repair and highlight a potential vulnerability in radioresistant tumors.

DNA repair↗

PubMed2025

Potential therapeutic targets for ovarian hyperstimulation syndrome revealed by proteome-wide mendelian randomization and colocalization analysis.

Ovarian hyperstimulation syndrome (OHSS) is a severe complication associated with assisted reproductive technologies, characterized by metabolic, immune and vascular disorders. Understanding the molecular mechanisms underlying OHSS could reveal potential therapeutic targets and improve patient outcomes. In this study, We aimed to utilize proteome-wide Mendelian randomization (MR) and colocalization analysis to identify plasma proteins associated with OHSS and evaluate their potential as therapeutic targets through druggability assessment. We employed proteome-wide MR analysis summary data-based Mendelian randomization (SMR) analysis and phenome-wide association study (PheWAS) analysis to establish causal relationships between plasma proteins and OHSS. Colocalization analysis confirmed overlaps between proteins and genetic signals associated with OHSS. Pathway and network analyses were conducted to explore biological functions and protein interactions, while drug-target databases were queried for potential therapeutic interventions. Our results showed that 4 key proteins, including Suprabasin (SBSN), SLAMF4 (CD244), Enolase 3 (ENO3) and Thioredoxin domain-containing protein 12 (TXNDC12) were identified as significant contributors to OHSS. Pathway enrichment and interaction analyses further supported their involvement in metabolic, immune and structural pathways related to OHSS. Drug availability for colocalized proteins reveled potential drug targets for ENO3 (2-deoxy-D-glucose), CD244 (lenalidomide) and TXNDC12 (Auranofin), while no potential drug targets were identified for SBSN. Over all, our study identified15 plasma proteins, including SBSN, CD244, ENO3, and TXNDC12, as key contributors to the risk of OHSS through MR and colocalization analysis. These proteins were involved in metabolic regulation, immune response and antioxidant pathways, highlighting potential therapeutic targets and suggesting new directions for treatment strategies.

Humans↗

PubMed2006

Differential and spermatogenic cell-specific expression of DMRT1 during sex reversal in protogynous hermaphroditic groupers.

DMRT1 has been suggested to play different roles in sex determination and gonad differentiation, because different expression patterns have been reported among different vertebrates. The groupers, since their gonads first develop as ovary and then reverse into testis, have been thought as good models to study sex differentiation and determination. In this study, we cloned the full-length cDNAs of DMRT1 gene from orange-spotted grouper (Epinephelus coioides), and prepared corresponding anti-EcDMRT1 antiserum to study the relationship of DMRT1 to sex reversal. One important finding is that the grouper DMRT1 is not only differentially expressed in different stage gonads, but also restricted to specific stages and specific cells of spermatogenesis. Grouper DMRT1 protein exists only in spermatogonia, primary spermatocytes and secondary spermatocytes, but not in the supporting Sertoli cells. Moreover, we confirmed that EcSox3 is expressed not only in oogonia and different stage oocytes, but also in Sertoli cells and spermatogonia, and EcSox9 is expressed only in Sertoli cells. The data suggested that grouper DMRT1 might be a more specific sex differentiation gene for spermatogenesis, and play its role at the specific stages from spermatogonia to spermatocytes. In addition, no introns were found in the grouper DMRT1, and no duplicated DMRT1 genes were detected. The finding implicates that the intronless DMRT1 that is able to undergo rapid transcriptional turnover might be a significant gene for stimulating spermatogenesis in the protogynous hermaphroditic gonad.

Amino Acid Sequence↗

PubMed2006

Solution structure of the second SH3 domain of human CMS and a newly identified binding site at the C-terminus of c-Cbl.

CMS, cas ligand with multiple Src homology 3 (SH3) domains, belongs to a family of ubiquitously expressed adaptor proteins. Among the CMS binding proteins, c-Cbl has been mostly extensively studied. It was reported that the motif PKPFPR (residues 824-829) of c-Cbl can bind to the N-terminus SH3 domains of CMS. Here we report the solution structure of the second SH3 domain of CMS (CMS_SH3_B), furthermore, we have identified that a peptide from residues 701 to 714 of c-Cbl (Cbl-p), i.e. MTPSSRPLRPLDTS, can specially bind to CMS_SH3_B using NMR chemical shift perturbation, suggesting that the peptide is a new potential CMS binding site. Among the peptide, TPSSRPLR is the core binding motif and Arg709 plays a key role in the interaction. Cbl-p binding interface on CMS_SH3_B along a hydrophobic channel is composed of RT loop, n-Src loop and beta4 strand and divided into three pockets. This work indicates the solution structure of CMS_SH3_B bears the canonical beta-beta-beta-beta-alpha-beta fold and a new binding site in c-Cbl involved in its interaction with CMS, which probably contributes to the clustering of CMS. All the information provided here should be beneficial for the future functional study of CMS.

Adaptor Proteins, Signal Transducing↗

PubMed2006

A modified back-etch method for preparation of plan-view high-resolution transmission electron microscopy samples.

A modified back-etch method is described that has been successfully used to prepare samples of thin films and nanoparticles on Si wafer substrates for examination by high-resolution transmission electron microscopy (HRTEM). This process includes ultrasonic cutting, abrasive pre-thinning and a two-stage etching procedure. Unlike previous reports of back-etching methods, tetramethyl ammonium hydroxide, which has a very high-etching selectivity of Si to SiO(2), is used for the final etching to allow removal of the Si without degradation of the SiO(2) membrane. An innovative wrapping method is also described. This novel approach reduces the preparation time for HRTEM samples to <1 h per sample for groups of 10 or more samples. As an example, the preparation of FePt nanoparticle samples for HRTEM imaging is described.

Diphosphates↗

PubMed2006

Binding model of human coactosin-like protein with filament actin revealed by mutagenesis.

Human coactosin-like protein (CLP) is a small (MW approximately 17 kDa) evolutionarily conserved actin-binding protein. It can bind to actin filaments but not globular actin and belongs to the fourth class of ADF-H-domain-containing proteins. Human CLP can also bind to 5LO, which plays an important role in cellular leukotriene synthesis. Although the structure of hCLP has been determined by both NMR and X-ray experiments, how hCLP binds to the actin filament is still a controversial question. To obtain insights into the structure of the complex, we studied the three-dimensional structure and backbone dynamics of hCLP using multidimensional NMR spectroscopy. Guided by the solution structure of the protein, a series of site-directed mutants were generated and their F-actin-binding activities were measured by high-speed cosedimentation assays. Furthermore, the structure model of the hCLP-F-actin complex was proposed using computational docking with the docking results filtered by the mutation data. Several previously untested residues (including T66, L89, R91, K102, D116 and E119) in hCLP were found important for the F-actin-binding activity. The extended region of beta4-beta5 of hCLP (residue 66-75) was found very flexible and very important for F-actin binding. The C-terminal residues of hCLP were not involved in F-actin binding, which was different from UNC-60B. Based on our hCLP-F-actin-binding model, different affinities of the four classes of ADF-H domain containing proteins for F-actin were explained.

Actins↗

PubMed2006

High-speed, whole-column fluorescence imaging detection for isoelectric focusing on a microchip using an organic light emitting diode as light source.

An integrated and simplified microfluidic device using a 250 microm x 1-4 cm of organic light emitting diode (OLED) array as a two-dimensional light source for single-channel and multichannel whole-column imaging detection was developed. This fluorescence detection system was used for isoelectric focusing (IEF) of R-phycoerythrin in a microchip. The IEF conditions were optimized, and the total analysis time was extremely reduced to 30 s for 2-cm-long microchannels at 700 V/cm of electric field strength without the presence of electroosmotic flow. The compression of pH gradient caused by electrolytes drawing into the microchannels was efficiently restrained when 1% hydroxylpropylmethyl cellulose in 2% ampholyte was used as the carrier for IEF. Under optimized IEF conditions, the detection limit of this system was approximately 0.6 microg/mL or 45 pg at 75 nL/column injection of R-phycoerythrin. This OLED-induced fluorescence detection system for WCID provides a high-speed IEF technique with quantitative ability and the potential for high integration and throughput microchip systems.

Fluorescence↗

PubMed2006

Radiotherapy as primary treatment for stage IE and IIE nasal natural killer/T-cell lymphoma.

UNLABELLED: PURPOSE The optimal therapy remains unclear for nasal natural killer (NK)/T-cell lymphoma. The purpose of this study is to analyze the outcome of radiotherapy as the primary treatment for localized stage IE and IIE diseases. PATIENTS AND METHODS: One hundred five patient cases were reviewed. There were 83 stage IE and 22 stage IIE patients. All except three patients received radiotherapy (RT) alone or RT combined with chemotherapy (CT; combined-modality therapy [CMT]). Overall, 31 patients were treated with RT alone, 34 with RT followed by CT, 37 with CT followed by RT, and three with CT alone. RESULTS: Five-year overall survival (OS) and progression-free survival (PFS) for all patients were 71% and 59%, respectively. The 5-year OS and PFS were 78% and 63% for stage IE, and 46% and 40% for stage IIE, respectively. Complete response (CR) was achieved in 91 patients (87%) after RT and/or CT. Initial RT resulted in a superior CR as compared with initial CT, with 54 (83%) of 65 patients achieving CR with initial RT, versus only eight (20%) of 40 after initial CT. For 102 patients who received RT with or without CT, the outcome of primary treatment with RT alone was compared with that of CMT. Five-year OS and PFS was 66% and 61% for RT alone, and 76% and 61%% for CMT, respectively (OS, P = .6433; PFS, P = .8391). CONCLUSION: RT as primary therapy resulted in good outcome in early-stage disease, and the addition of CT to RT was not accompanied by an improvement in survival.

Adolescent↗

PubMed2006

[Prognostic factors of primary non-Hodgkin's lymphoma of the nasal cavity--a report of 129 cases].

BACKGROUND & OBJECTIVE: The prognosis of primary non-Hodgkin's lymphoma (NHL) of the nasal cavity was poor, and the distant metastasis and local relapse rates are high. This study was to analyze the prognostic factors of this disease. METHODS: Clinical data of 129 patients with pathologically confirmed nasal NHL, treated from Jan. 1996 to Dec. 2002, were retrospectively reviewed. Of the 129 patients, 116 were diagnosed as nasal NK/T-cell lymphoma. According to the Ann Arbor staging system, 102 patients had stage IE disease, 22 stage IIE, and 5 stage IVE. Among the 124 patients with stage IE or IIE disease, 22 received radiotherapy alone, 7 received chemotherapy alone, and 95 received combined modality therapy (CMT). Of the patients received CMT, 45 received radiotherapy followed by chemotherapy, and 50 received chemotherapy followed by radiotherapy. The stage IVE patients received chemotherapy with or without radiotherapy. RESULTS: The 5-year overall survival (OS) and disease-freely survival (DFS) rates for all patients were 68.0% and 55.8%, respectively. The 5-year OS and DFS rates were 71.7% and 60.9% for stage IE patients, and 70.6% and 47.0% for stage IIE patients, respectively (P>0.05). The 5-year OS and DFS rates were significantly higher in the patients who achieved complete response (CR) than in those who didn't (83.1% vs. 18.0%, 68.0% vs. 15.5%, P<0.01). The 5-year OS rates of the patients with international prognostic index (IPI) score of 0, 1, and > or =2 were 81.1%, 60.1%, and 14.3% (P<0.01), respectively; the 5-year DFS rates were 68.8%, 44.6%, and 22.5% (P<0.01), respectively. Thirty-eight patients developed progression or relapse, with distant extranodal dissemination (78.9%) as the primary pattern of failure. Univariate analysis showed that CR rate, PS, IPI, and modified IPI were related to prognosis. Multivariate analysis showed that CR rate was an independent prognostic factor. CONCLUSIONS: CR rate after treatment is an important prognostic factor of nasal NHL. Distant metastasis is the main failure pattern of nasal NHL.

Adolescent↗

PubMed2006

[Treatment option and outcome for patients with primary non-Hodgkin's lymphoma of the nasal cavity].

OBJECTIVE: The optimal treatment for primary non-Hodgkin's lymphoma (NHL) of the nasal cavity remains controversial. This study was to analyze the initial response rate of radiotherapy and chemotherapy, and the influence of different treatment modalities on prognosis. METHODS: From January 1996 to December 2002, the clinical data of 129 patients with previously untreated nasal NHL were retrospectively reviewed with all lesions confirmed by pathology. 116 patients were morphologically diagnosed as having nasal NK/T cell lymphoma. The immunophenotype was available in 57 cases and 52 (91.2%) of them were confirmed as NK/T-cell lymphoma. According to the Ann Arbor Staging System, 102 patients had stage I(E), 22 stage II(E), and 5 stage IV(E) disease. Among the 124 patients with stage I(E) and II(E) diseases, 22 patients received radiotherapy alone, 7 chemotherapy alone, and 95 combined modality therapy (CMT). Of these 95 patients treated with CMT, 45 patients were treated with radiotherapy followed by chemotherapy, and 50 with chemotherapy followed by radiotherapy. The primary treatment for stage IV(E) patients was chemotherapy with or without radiotherapy to the primary tumor. RESULTS: The overall 5-year survival (OS) and disease free survival (DFS) for all patients was 68.0% and 55.8%, respectively. It was 71.7% and 60.9% for stage I(E), and 70.6% and 47.0% for stage II(E), respectively (P > 0.05). The OS and DFS at the 5th year were 83.1% and 68.0% for patients who achieved complete response (CR), and 18.0% and 15.5% for those who did not, respectively (P = 0.000). Of the 124 patients with stage I(E) and II(E) disease, 67 patients were treated with radiotherapy alone (22 patients) or radiotherapy followed by chemotherapy (45), whereas 57 were treated with chemotherapy followed by radiotherapy (50) or chemotherapy alone (7). The CR rate after radiotherapy was 74.7%, however, it was only 19.3% after chemotherapy (P = 0.000). Of the 46 patients with PR, SD or PD after chemotherapy, 42 still had locoreginally localized lesion and 31 of these patients achieved CR by following radiotherapy which revealed satisfactory results. For stage I(E) and II(E) disease, the 5-year OS and DFS were 76.0% and 65.0% for radiotherapy with or without chemotherapy, and 74.4% and 56.2% for chemotherapy followed by radiotherapy. The difference was statistically not significant. However, 7 stage I(E) and II(E) patients were treated with chemotherapy alone, and 4 of them died of disease progression, with 1-year survival of 26.7%. CONCLUSION: The majority of Chinese patients with primary nasal NHL are NK/T cell in origin. The complete response rate by radiotherapy is much higher than that by chemotherapy. The addition of chemotherapy to radiotherapy did not improve the survival of patients with early stage nasal lymphoma. Radiotherapy is suggested as the primary treatment for stage I(E) and II(E) nasal NK/T cell lymphoma.

Adult↗

PubMed2006

[Prognostic factors and treatment outcome in early stage nasal NK/T cell lymphoma].

OBJECTIVE: To analyze initial response rate of radiotherapy and chemotherapy for early nasal NK/T-cell lymphoma, and its prognostic factors. METHODS: From January 1996 to December 2002, 116 patients with nasal NK/T-cell lymphoma were diagnosed pathologically. Immunophenotyping was performed in 50 cases. According to Ann Arbor staging classification, 95 patients were stage I(E) and 21 II(E). Of the 116 patients, 22 received radiotherapy alone, 6 chemotherapy alone and 88 combined modality therapy (CMT), including, 41 radiotherapy followed by chemotherapy, and 47 chemotherapy followed by radiotherapy. RESULTS: The 5-year overall survival (OS) rate and disease free survival (DFS) rate for all patients was 74.1% and 61.5%, respectively. For stage I(E) and II(E) patients, the 5-year OS rate was 75.1% and 68% (P = 0.45), and DFS rate was 64.7% and 47.8%, respectively (P = 0.07). The 5 year OS rate and DFS rate were 86.5% and 71.5% for patients who achieved complete response (CR), and 18.4% and 17.2% for those who didn't, respectively (P = 0.000). Sixty-three patients were treated with radiotherapy alone or radiotherapy followed by chemotherapy, while 53 with chemotherapy followed by radiotherapy or chemotherapy alone. The CR rate for radiotherapy was 74.6% while for chemotherapy was 20.8% (P = 0.000). The 5-year OS rate and DFS rate were 76.8% and 65.4% for radiotherapy with or without chemotherapy, and 78.8% and 61.8% for chemotherapy followed by radiotherapy (P > 0.05). Multivariate analysis by COX regression showed that CR rate was the only independent prognostic factor. CONCLUSION: The CR rate of radiotherapy is much higher than that of conventional chemotherapy. Addition of chemotherapy to radiotherapy do not improve the survival of patients with early stage nasal NK/T-cell lymphoma. Radiotherapy is the primary treatment for stage I and II nasal NK/T-cell lymphoma.

Adolescent↗

PubMed2006

[Spectroscopic methodology for the measurement of tokamak plasma].

The states and the distributions of the plasma in the tokamak can be obtained by measuring the spectrum. Since there are many different objects to be measured, many different apparatuses are used to get a better result. Some methods for the measurement are listed in this article. Also the measuring range of each method and some results are listed. On the other hand, a new method was developed according to the conditions of the lab.

English Abstract↗

PubMed2005

Molecular cloning and expression pattern of 14 kDa apolipoprotein in orange-spotted grouper, Epinephelus coioides.

A novel fish-specific apolipoprotein (apo-14 kDa) has been recently cloned from eel and pufferfish. However, its expression pattern has not been elucidated. In this study, EcApo-14 has been screened from hypothalamic cDNA library of male orange-spotted grouper, which shows 62.9%, 51%, 46.9%, 43.2%, and 31.9% identities to Apo-14 of European flounder, pufferfish, Japanese eel, gibel carp, and grass carp, respectively. RT-PCR analysis reveals that this gene is first transcribed in neurula embryos and maintains a relatively stable expression level during the following embryogenesis. EcApo-14 transcripts are at a very high level during embryonic and early larval development in the yolk syncytial layer (YSL), and decrease in YSL and form intense staining in liver at 3 days after hatching. In adult tissues, EcApo-14 is predominantly expressed in liver and brain. The data suggested that EcApo-14 might play an important role in liver and brain morphogenesis and growth.

Amino Acid Sequence↗

PubMed2005

A microfluidic device using a green organic light emitting diode as an integrated excitation source.

A simply fabricated microfluidic device using a green organic light emitting diode (OLED) and thin film interference filter as integrated excitation source is presented and applied to fluorescence detection of proteins. A layer-by-layer compact system consisting of glass/PDMS microchip, pinhole, excitation filter and OLED is designed and equipped with a coaxial optical fiber and for fluorescence detection a 300 microm thick excitation filter is employed for eliminating nearly 80% of the unwanted light emitted by OLEDs which has overlaped with the fluorescence spectrum of the dyes. The distance between OLED illuminant and microchannels is limited to approximately 1 mm for sensitive detection. The achieved fluorescence signal of 300 microM Rhodamine 6G is about 13 times as high as that without the excitation filter and 3.5 times the result of a perpendicular detection structure. This system has been used for fluorescence detection of Rhodamine 6G, Alexa 532 and BSA conjugates in 4% linear polyacrymide (LPA) buffer (in 1 x TBE, pH 8.3) and 1.4 fmol and 35 fmol mass detection limits at 0.7 nl injection volume for Alexa and Rhodamine dye have been obtained, respectively.

Acrylic Resins↗

PubMed2005

Contribution of dicofol to the current DDT pollution in China.

High DDT concentrations and o,p'-DDT/p,p'-DDT ratios observed in the air over Taihu Lake, a lake near Shanghai, China, led us to suggest that current use of dicofol in the area north of the lake was the main source of the measured DDTs. To examine this hypothesis, samples of commercially available formulated dicofol in China were collected in 2003 to measure the impurities of DDT related compounds (DDTs). The o,p'-DDT/p,p'-DDT ratio in the samples was 7.0, close to the observed value in the air over Taihu Lake. Average contents of o,p'-DDT, p,p'-CI-DDT, o,p'-DDE, and p,p'-DDT in the samples were 114, 69, 44, and 17 g per kg dicofol, respectively. On the basis of a production and distribution survey, total input of DDTs to the environment from the dicofol use in China was estimated to be 8770 t between 1988 and 2002. "Dicofol type DDT pollution", defined as DDT pollution caused by dicofol use and characterized with high o,p'-DDT/p,p'-DDT ratio, might be serious in China, especially in southern and eastern China. The conversion of p,p'-CI-DDT to p,p'-DDE can lead to high p,p'-DDE/p,p'-DDT ratio and could mislead the evaluation of p,p'-DDT resident time in the environment. Therefore, more studies on p,p'-CI-DDT in the environment are needed.

Air Pollutants↗

PubMed2005

[Establishment of rhesus model for haploidentical hematopoietic stem cell transplantation with nonmyeloablative conditioning].

To study if rhesus haploidentical hematopoietic stem cell transplantation model can be established by non-myeloablative conditioning, parent monkeys were used as donors, offspring monkeys were used as recipients. The recipient monkeys received a nonmyeloablative conditioning consisting of fludarabine, cyclophosphamide, total body irradiation and rabbit anti-human thymocyte globulin. Cyclosporine, mycophenolate mofetil and anti CD25 antibody were used for GVHD prevention. Donor mobilized peripheral blood stem cells were transplantated on day 0. Hematopoietic recovery, chimerism level, GVHD were assessed regularly. The results indicated that hematopoietic recoveries in all 4 cases were observed within 8 days after transplantation. Donor hematopoietic chimerism could be induced in all cases, chimerism analysis showed full donor chimerism (FDC) in case 3 and 4, and II to III grade GVHD developed on day 12 and 14. In case 1, only low level donor chimerism was detected on day 7, and transplantation rejection happened eventually. Unfortunately, kidney failure happened in case 2 after conditioning and died several days later, chimerism analysis showed 50% donor rate on day 7. It is concluded that the rhesus transplantation model was successfully established by nonmyeloablative conditioning for striding over the MHC barrier. This rhesus monkey model would provide a basis for future research.

Animals↗

PubMed2005

[Establishment of a rhesus haploidentical hematopoietic stem cell and mesenchymal stem cell transplantation model by nonmyeloablative conditioning].

OBJECTIVE: To establish rhesus haploidentical hematopoietic stem cell transplantation model by nonmyeloablative conditioning, and examine the effects of mesenchymal stem cells (MSC) in haploidentical transplantation. METHODS: The recipient haploidentical rhesus monkeys were conditioned with a nonmyeloablative regimen consisted of fludarabine, cyclophosphamide, 200 cGy total body irradiation, and rabbit anti-human thymocyte globulin. Cyclosporine A, mycophenolate mofetil and anti CD25 antibody were used for graft versus host disease (GVHD) prophylaxis. Rhesus monkeys in one group were given hematopoietic stem cell (HSC) only, while in the other group HSC combined with MSC. The differences in hematopoiesis recovery, chimerism level, and GVHD between the two groups were evaluated. RESULTS: Stable chimerism could be achieved in recipient monkeys. Hematopoiesis recovery was mainly related with chimerism level. MSC seemed capable of facilitating HSC engraftment, as there were more mixed chimerism and less GVHD occurrence in the HSC combined with MSC recipient group. CONCLUSION: A rhesus haploidentical hematopoietic stem cell transplantation model is successfully established by nonmyeloablative conditioning. MSC was of great benefit to haploidentical transplantation.

Animals↗

PubMed2004

A microfluidic device based on gravity and electric force driving for flow cytometry and fluorescence activated cell sorting.

A novel method based on gravity and electric force driving of cells was developed for flow cytometry and fluorescence activated cell sorting in a microfluidic chip system. In the experiments cells flowed spontaneously under their own gravity in a upright microchip, passed through the detection region and then entered into the sorting electric field one by one at an average velocity of 0.55 mm s(-1) and were fluorescence activated cell sorted (FACS) by a switch-off activation program. In order to study the dynamical and kinematic characteristics of single cells in gravity and electric field of microchannels a physical and numerical module based on Newton's Law of motion was established and optimized. Hydroxylpropylmethyl cellulose (HPMC) was used to minimize cell assembling, sedimentation and adsorption to microchannels. This system was applied to estimate the necrotic and apoptotic effects of ultraviolet (UV) light on HeLa cells by exposing them to UV radiation for 10, 20 or 40 min and the results showed that UV radiation induced membrane damage contributed to the apoptosis and necrosis of HeLa cells.

Apoptosis↗