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L-selectin shedding induced by various cytokines is crucial in activating neutrophils (PMNs) in inflammatory cascade. While the real-time shedding in vivo lasts ~10 min after PMN activation, the impact of time-dependent shedding on binding kinetics of membrane-remaining L-selectins to its ligands is poorly understood at transient or steady state. Here, we developed an in vitro L-selectin shedding dynamics approach, together with competitive assays of cell adhesion, and proposed a theoretical model for quantifying the impact of real-time shedding on the binding kinetics of membrane-remaining L-selectins to P-selectin glycoprotein ligand-1 (PSGL-1). Our data indicated that the extent of L-selectin shedding on PMA activation is higher, but the terminating time is longer for Jurkat cells than those for human PMNs. Meanwhile, fMLF or IL-8 stimulation yields the longer terminating time than that on PMA stimulation but results in a similar shedding extent for PMNs. L-selectin shedding reduces L-selectin-PSGL-1-mediated cell adhesion in three ways: decreasing membrane-anchored L-selectins, increasing soluble L-selectins competitively binding to ligands, and presenting conformational alteration of membrane-remaining L-selectins themselves. Compared with those on intact cells, the binding affinities of membrane-remaining L-selectin-PSGL-1 pairs were all enhanced at initial and lowered at the late shedding phase for both PMN and Jurkat cells even with varied transition time points. The rolling velocities of both PMNs and Jurkat cells were increased following mechanically or biochemically induced shedding of L-selectin under shear flow. These findings help to further our understanding of the function of time-dependent L-selectin shedding during the inflammation cascade.

Flowing polymorphonuclear neutrophils (PMNs) are forced to recruit toward inflamed tissue and adhere to vascular endothelial cells, which is primarily mediated by the binding of β 2 -integrins to ICAM-1. This process is distinct among different organs such as liver and brain; however, the underlying kinetic and mechanical mechanisms regulating tissue-specific recruitment of PMNs remain unclear. Here, binding kinetics measurement showed that ICAM-1 on murine hepatic sinusoidal endothelial cells (LSECs) bound to lymphocyte function-associated antigen-1 (LFA-1) with higher on- and off-rates but lower effective affinity compared with macrophage-1 antigen (Mac-1), whereas ICAM-1 on cerebral endothelial cells (BMECs or bEnd.3 cells) bound to LFA-1 with higher on-rates, similar off-rates, and higher effective affinity compared with Mac-1. Physiologically, free crawling tests of PMN onto LSEC, BMEC, or bEnd.3 monolayers were consistent with those kinetics differences between two β 2 -integrins interacting with hepatic sinusoid or cerebral endothelium. Numerical calculations and Monte Carlo simulations validated tissue-specific contributions of β 2 -integrin-ICAM-1 kinetics to PMN crawling on hepatic sinusoid or cerebral endothelium. Thus, this work first quantified the biophysical regulation of PMN adhesion in hepatic sinusoids compared with cerebral endothelium.

Directed movement of eukaryotic cells toward spatiotemporally varied chemotactic stimuli enables rapid intracellular signaling responses. While macroscopic cellular manifestation is shaped by balancing external stimuli strength with finite internal delays, the organizing principles of the underlying molecular mechanisms remain to be clarified. Here, we developed a novel modeling framework based on a simple seesaw mechanism to elucidate how cells repeatedly reverse polarity. As a key feature of the modeling, the bottom module of bidirectional molecular transport is successively controlled by three upstream modules of signal reception, initial signal processing, and Rho GTPase regulation. Our simulations indicated that an isotropic cell is polarized in response to a graded input signal. By applying a reversal gradient to a chemoattractant signal, lamellipod-specific molecules (i.e. PIP 3 and PI3K) disappear, first from the cell front, and then they redistribute at the opposite side, whereas functional molecules at the rear of the cell (i.e. PIP 2 and PTEN) act oppositely. In particular, the model cell exhibits a seesaw-like spatiotemporal pattern for the establishment of front and rear and interconversion, consistent with those related experimental observations. Increasing the switching frequency of the chemotactic gradient causes the cell to stay in a trapped state, further supporting the proposed dynamics of eukaryotic chemotaxis with the underlying cytoskeletal remodeling.

The causal relationship between conformational folding and disulfide bonding in protein oxidative folding remains incompletely defined. Here we show a stage-dependent interplay between the two events in oxidative folding of C-reactive protein (CRP) in live cells. CRP is composed of five identical subunits, which first fold spontaneously to a near-native core with a correctly positioned C-terminal helix. This process drives the formation of the intra-subunit disulfide bond between Cys36 and Cys97. The second stage of subunit folding, however, is a non-spontaneous process with extensive restructuring driven instead by the intra-subunit disulfide bond and guided by calcium binding-mediated anchoring. With the folded subunits, pentamer assembly ensues. Our results argue that folding spontaneity is the major determinant that dictates which event acts as the driver. The stepwise folding pathway of CRP further suggests that one major route might be selected out of the many in theory for efficient folding in the cellular environment.

The tracheocutaneous fistula after tracheostomy is a complex clinical problem. An ideal fistula closure is still difficult at present though a variety of fistula-closing methods have been reported in the literature. We used a turnover skin flap to cover the fistula. All the procedures were completed at bedside under local anesthesia. The fistula was successfully closed and well healed without complications within 7-9 days. It has been proven that this operation is simple, effective, and safe.

We retrospectively analyzed 449 patients with AML under the WHO classification of AML 2008 and probed implications of this classification in diagnosis and treatment of acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) among them. The clinical presentations, biological features, treatments, and prognosis of patients diagnosed with AML-MRC were analyzed and compared with those of AML not otherwise specified (AML-NOS). In all patients, 115 (25.6%) were diagnosed as AML-MRC including 64 males and 51 females with median onset age of 48 years (range from 17 to 78). Their complete remission (CR) rate was 60.9% and relapse rate was 57.1%. The observed median overall survival (OS) and disease-free survival (DFS) were 10 and 5 months, respectively, which was significantly shorter than those of AML-NOS patients (P < 0.05). The prognosis of AML-MRC patients with myelodysplastic syndrome (MDS)-related cytogenetics sole was similar to those with history of MDS or myelodysplastic/myeloproliferative neoplasm (MDS/MPN). Patients with MDS-related cytogenetic abnormalities and/or history of MDS or MDS/MPN predisposed significantly shortened CR, OS, and DFS than AML-MRC patients with only multilineage dysplasia (MLD) and AML-NOS patients (P < 0.05). Multivariate analysis showed that age, cytogenetics, and history of MDS or MDS/MPN were independent prognostic factors. Patient diagnosed as AML-MRC presented distinctive clinical and biological features. Presence of MLD does not change the prognosis., (© 2014 Wiley Periodicals, Inc.)

Inwardly rectifying K(+) (Kir) channels set the resting membrane potential and regulate cellular excitability. The activity of Kir channels depends critically on the phospholipid PIP(2). The molecular mechanism by which PIP(2) regulates Kir channel gating is poorly understood. Here, we utilized a combination of computational and electrophysiological approaches to discern structural elements involved in regulating the PIP(2)-induced gating kinetics of Kir2 channels. We identify a novel role for the cytosolic GH loop. Mutations that directly or indirectly affect GH loop flexibility (e.g. V223L, E272G, D292G) increase both the on- and especially the off-gating kinetics. These effects are consistent with a model in which competing interactions between the CD and GH loops for the N terminus regulate the gating of the intracellular G loop gate.

A phylogenetic hypothesis for the Asian newts of the Tylototriton asperrimus group was generated using data from two mitochondrial fragments including COI and the ND1-ND2 regions. Four distinct clades (A, B, C, D) were resolved with high nodal support within this monophyletic group. Clade A included T. asperrimus, T. hainanensis, T. notialis, "T. vietnamensis", and two unnamed salamander populations from Vietnam. Clade A, constituted the sister group of clades B + C. Newly identified clade C likely represents a new cryptic species. Clade C was the sister group of T. wenxianensis. The true T. vietnamensis exclusively constituted clade D. Our results bring into question some previous taxonomic decisions, and a revision is required. This study illustrates the necessity to include samples from type localities in taxonomic studies, and highlights the importance of fine-grained geographical sampling.

This study was purposed to investigate the differences of cyto biological characteristics and protein expression levels between bortezomib-resistant T-lymphoblastic lymphoma/leukemia cell lines JurkatB containing PSMB5 G322A mutation and their parent cell line Jurkat, The cytotoxicities of bortezomib and chemotherapeutic drugs to JurkatB5 cells (end selection concentration of bortezomib was 500 nmol/L), JurkatB8 (end selection concentration 800 nmol/L) and Jurkat cells were analyzed. The cell growth curves were drawn with viable cell counts by trypan blue assay, the colony formation rate were assayed by soft-agar colony culture, and the cell distributions in cell cycle were analyzed by flow cytometry, mRNA expression levels of multidrug resistance (MDR) genes MDR1, LRP and MRP were measured by real-time fluorescence quantitative RT-PCR, the differences of protein expression levels were detected by SpringBio antibody microarray containing 720 proteins. The results showed that the drug resistance multiples for 48 hours of JurkatB5 and JurkatB8 cells (relative to Jurkat) to bortezomib were increased by 33.52 and 39.04 times, respectively. JurkatB5 and JurkatB8 cells did not display significant cross-resistance to daunorubicin, adriamycin, vindesine, and etoposide after exposure for 48 hours. There were no significant differences in the cell growth curve, colony formation rate and cell distributions in cell cycle between JurkatB5, JurkatB8 and Jurkat cells (p > 0.05). There were no significant differences of mRNA expression levels of MDR1, LRP, MRP between JurkatB5 and Jurkat cells (p > 0.05). There were 264 analyzable expression points detected by antibody microarray. Among them, 252 protein expression levels were not significantly different between JurkatB5, JurkatB8 and Jurkat cells (< 2-fold), including 15 drug resistance-related proteins. 12 proteins were detected at higher or lower expression levels in JurkatB5 or JurkatB8 cells then that in Jurkat cells (cell division cycle protein 34, cell division cycle protein 37, CD34 Type II, matrix metalloproteinase-2, tenascin, Golgi complex, involucrin, histone deacetylase 1, perforin, prolactin, retinoic acid receptor β, integrin β-1), but no proteins were detected in JurkatB5 and JurkatB8 cells with higher or lower expression levels than that in Jurkat cells. It is concluded that there are no significant differences in the characteristics of cellular biology between Jurkat and JurkatB with bortezomib-resistant and PSMB5 G322A mutation. There are no significant phenotype change of MDR and overexpression of genes related to MDR in PSMB5 mutated cells. There are no significantly differential expressions of a majority of known proteins related to drug resistance, tumor cells growth, proliferation, apoptosis, malignancy degree, aggressiveness.

Objective: To investigate the urodynamic changes in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and nocturnal polyuria., Methods: From Sept. 2002 to Jun. 2008, 23 patients with nocturnal polyuria were diagnosed as having OSAHS by polysomnography (PSG). The number and output of nocturia, the osmotic pressure and the excretion of Na(+) were recorded during both the PSG night and CPAP titrating night. Plasma levels of brain natriuretic peptide (BNP) and atrial natriuretic peptides (ANP) were also measured at 11PM in the 2 nights and 7AM in the next mornings. Urodynamic studies including urine flow, bladder pressure during filling, pressure-flow study during voiding and urethral pressure were carried out in these patients. Urodynamic studies were performed again after treatment with CPAP for 3 months., Results: PSG showed that the patients with nocturnal polyuria had moderate to severe OSAHS, in which the apnea-hypopnea index (AHI) being 48 ± 15 events per hour. The number of nocturnal voiding during the PSG night was more than that during the CPAP titrating night. During the PSG night, the output of nocturia, the nocturia excretion of Na(+), ANP levels (at 7am in the next morning after PSG night) increased and the osmotic pressure of nocturia decreased. CPAP therapy could reverse these abnormalities. The main characteristics of urodynamics in these patients included weak detrusor contraction, hypoesthesia in filling cystometry, and decreased bladder compliance, and detrusor external sphincter dyssynergia. After 3 months of CPAP treatment, both the motility of the detrusor of bladder and the bladder compliance improved., Conclusions: CPAP therapy can effectively reverse the nocturnal polyuria in OSAHS patients. In OSAHS patients, the features of nocturia, including the changes of output, osmotic pressure and the excretion of Na(+), may be related to the secretion of high-level of ANP. During the course of chronic progressively OSAHS pathophysiology, detrusor function of bladder may be damaged. CPAP therapy could decrease the nocturnal excretion of ANP, and improve the motility of the detrusor of bladder.

Background: Biphenotypic acute leukemia is a rare disorder that is difficult to diagnose. It displays features of both myeloid and lymphoid lineage. There is still a lack of studies in biphenotypic acute leukemia in a Chinese population. We present here a comprehensive investigation of the clinical and biological characteristics, and outcome of biphenotypic acute leukemia in our hospital in over a seven year period., Design and Methods: We retrospectively analyzed 452 adult acute leukemia patients diagnosed according to French-American-British (FAB) classification and biphenotypic acute leukemia diagnosed according to European Group for the Immunological Characterization of Leukemias (EGIL) classification, respectively. Biological characteristics, response to treatment, and outcome were examined in biphenotypic acute leukemia patients and compared with that in acute myeloid leukemia and acute lymphoblastic leukemia patients with complete follow-up profiles diagnosed in the same period., Results: Of 452 acute leukemia patients, 21 cases (4.6%) were diagnosed as biphenotypic acute leukemia. Among them, 14 (66.7%) were B lymphoid and myeloid, 5 (23.8%) were T lymphoid and myeloid, one (4.8%) was T/B lymphoid and one (4.8%) was trilineage differentiation. When compared with acute myeloid leukemia and acute lymphoblastic leukemia, patients with biphenotypic acute leukemia showed significantly higher incidence of CD34 antigen expression, unfavorable karyotypes, and extramedullary infiltration (p<0.05). In this cohort of patients with biphenotypic acute leukemia, t(9;22) was the most common abnormality in chromosome structure. The median disease-free survival and overall survival in biphenotypic acute leukemia patients was five months and ten months, respectively, significantly shorter than those in acute myeloid leukemia and acute lymphoblastic leukemia patients (p<0.05)., Conclusions: The prognosis of biphenotypic acute leukemia patients is poor when compared with de novo acute myeloid leukemia or acute lymphoblastic leukemia. Biphenotypic acute leukemia patients showed a much higher incidence of CD34 antigen expression, complex abnormal karyotype, extramedullary infiltration, relapse, and resistance to therapy after relapse.

The aim of this study was to explore the synergistic effect of arsenic trioxide and bortezomib on apoptosis of Raji cell line. The cells were treated with arsenic trioxide, bortezomib, low-dose arsenic trioxide combined with bortezomib, respectively. The cell viability and proliferative curve were estimated by trypan blue dye exclusion. The cell apoptosis and cell cycle status were analyzed by flow cytometry. The apoptosis related elements such as caspase-3, BCL-2, BAX, JNK2 and IkappaB-alpha, were measured with Western blot. The results showed that compared with cells treated with mentioned above drugs alone, the proliferative potential of cells in combination group was significantly inhibited (p < 0.01), and apoptosis rate markedly increased (p = 0.001), while obvious cell cycle arrest was not observed. On the protein level, the expression of Caspase-3, BAX and IkappaB-alpha increased, while the expression of BCL-2, and JNK2 decreased. It is concluded that low-dose arsenic trioxide combined with bortezomib synergistically induced apoptosis in Raji cell line which may be mediated by inhibiting NK-kappaB and JNK2 signaling.

Objective: To evaluate the therapeutic efficiency and adverse effect of the fludarabine-containing regimens in the treatment of low grade non-Hodgkin's lymphoma., Methods: Thirty-two patients with low grade non-Hodgkin's lymphoma consisting of 19 primary one and 13 relapsed or refractory were treated with fludarabine-containing regimens, which included FMD (fludarabine, mitoxantrone and dexamethasone); FMC (fludarabine, cyclophosphamide and mitoxantrone) and FC ( fludarabine and cyclophosphamide)., Results: The average course completed in these 32 patients was 4.1 with a complete response rate (CR), partial response rate (PR) and overall response rate (OR) of 65.6%, 18.8% and 84.4% , respectively. There were no significant difference in CR, PR and OR between primary and relapsed or refractory group (71.4%, 21.0%, 92.4% vs. 46.2%, 13.1%, 59.3%, respectively). Myelotoxicity and immunotoxicity was the dominating adverse effects. Ill to IV grade granulocytopenia and thrombocytopenia were observed in 31.3% (10/32) and 9.4% (3/32) of these patients respectively. Infection developed in 7 patients, and two of them died of pulmonary infection. The median follow-up period was 16 months (1-30 months) with 2-year overall-survival rate (OS) and progression-free survival rate (PFS) of 93.8% and 84.4%, respectively. No significant difference was observed between primary and relapsed or refractory group in OS (100% vs. 76.9%) and PFS (94.7% vs. 69.2%)., Conclusion: Fludarabine-containing regimens is well tolerated and effective in the treatment of low grade non-Hodgkin's lymphoma.

The proteasome is primarily responsible for intracellular protein degradation. The abnormality of its activity is sign of tumorigenesis. It was confirmed that proteasome inhibitors have activities against a variety of malignancies. Bortezomib, the first proteasome inhibitor, obtained permission of clinical trial and on sale. Multiple myeloma patients treated with bortezomib have gained a high overall response rate and complete remission rate. A lot of studies on effects of proteasome inhibitors on leukemias, including plasma cell leukemia; chronic lymphocytic leukemia, adult T cell lymphoma/leukemia, chronic myeloid leukemia and acute myeloid leukemia, were reviewed in this article.

Objective: To investigate the mechanism of multi-drug resistance of K562-n/VCR cell line with both bcr-abl and mdr-1 expressions by clustering analysis of differential gene expression profiles., Methods: By DNA microarray technique, genes differentially expressed by K562-n/VCR and K562-n cell lines were identified and analyzed., Results: DNA microarray analysis of K562-n/VCR and K562-n cells was repeated three times and revealed 58 genes significantly differentially expressed among 12,800 genes arrayed. All but one was up-regulated in K562-n/VCR cells. The only gene down-regulated was a-myb. The up-regulated genes were MDR-associated genes, oncogenes, cytoskeleton, protein kinases and phosphatases, apoptotic and antiapoptotic factors, metabolism, transcriptional regulators associated with stress response, cell cycle checkpoint control, and genes for signal transduction proteins., Conclusion: These results indicate that, besides MDR-associated genes, other known and unknown genes may also be involved in the mechanism of multi-drug resistance.

Objective: To study the molecular mechanism of tumorigenicity in nude mice of human leukemia cell lines., Methods: K562-n, is a human leukemic cell line with much higher tumorigenecity in nude mice compared with the parental K562 cell line by repeated in vitro and in vivo passages. Genes differentially expressed between K562 and K562-n cells were analyzed by using DNA microarray technique., Results: Of 12 000 genes screened were differentially expressed significantly, among which 42 genes were up-regulated and 97 genes were down-regulated in K562-n cells. Eighty-five of the 139 genes have been registered in the GeneBank and 54 are unknown genes. The genes accessible from the GenBank include: 1. oncogenes and tumor-supressor genes, 2. genes related to transcription regulation, cell cycle and apoptosis, 3. genes related to cytoskeleton and cytokinetics, 4. genes related to metabolism and transport, 5. genes related to immune function. There were also some differentially expressed genes with mixed functions and some with unknown function differentially expressed., Conclusion: There are many genes differentially expressed between K562-n and K562 cells. The high tumorigenicity in nude mice of human leukemia cell line K562-n might be related to its specific gene expression profile.

Objective: To investigate the killing effects of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system on human malignant glioma cells in vitro., Methods: The pCMVCD plasmid was transfected into the U251 human malignant glioma cells using Lipofectamine 2000-mediated method. Resistant clones (named U251/CD cells) were isolated by screening with G418 presence. U251/CD cells were incubated with 5-FC in different concentrations to determine the number of viability cells (or cytotoxicity assay), and measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The concentrations of 5-fluorouracil (5-FU) in the media were measured by the high-performance liquid chromatography (HPLC) analysis., Results: The untreated U251 cells were insensitive to 5-FC, with the IC50 about 6 500 micromol/L. After the transfection, the IC50 was dramatically reduced to about 10 micromol/L. Therefore, gene transfection made G418-resistant clones (U251/CD cells) highly sensitive to 5-FC. HPLC analysis showed that 5-FU was detected in U251/CD cell medium., Conclusion: The killing effects of U251 cells modified by CD gene were induced by 5-FC, and the CD/5-FC system was feasible to treat glioma.

This paper analyzed the phylogenetic relationships and classification of pit vipers (Viperidae, Crotalinae) based on mitochondrial 12S rRNA gene sequence variations. We have sequenced mtDNA 12S rRNA gene about 370 bp fragment from Gloydius saxatilis Emelianov, Gloydius shedaoensis Zhao, Gloydius ussurriensis (Emelianov), Trimeresurus stejnegeri Schmidt and Deinagkistrodon acutus, Gloydius brevicaudus (Stejneger) from two different localities, respectively. Combined with the sequence of Dinodon semicarinatus from GenBank, we have constructed two molecular phylogenetic trees using both Maximum-parsimony analysis and Neighbor-joining. Our results support the following conclusions: (1) Deinagkistrodon is a valid genus; (2) we also discussed the origin of Gloydius shedaoensis and showed it is a subspecies of Gloydius saxatilis; (3) Gloydius brevicaudsu and Gloydius ussurriensis are classified two species.

The excretion pattern of TCA in urine of workers exposed to trichloroethylene and the correlation between concentration of TCA in urine and uptake amount of trichloroethylene were investigated by applying Head Space Gas Chromatography. We examined 33 unexposed subjects (control group) and 48 workers (exposure group). The results showed that the concentration of TCA in urine rose obviously after exposure to trichloroethylene. The concentration of TCA in urine and trichloroethylene exposure was positively correlated (X = 2.916Y + 4.619, r = 0.956 8). Based on the observation of 6 volunteers, we found that the concentration of TCA in urine reached its peak about 48 hours after exposure has ceased. It then slowly declined and did not recover completely up to 96 hours.