Publications by authors named "Wenwei Yan"

A growing body of evidence has substantiated the significance of quantitative phase imaging (QPI) in enabling cost-effective and label-free cellular assays, which provides useful insights into understanding the biophysical properties of cells and their roles in cellular functions. However, available QPI modalities are limited by the loss of imaging resolution at high throughput and thus run short of sufficient statistical power at the single-cell precision to define cell identities in a large and heterogeneous population of cells-hindering their utility in mainstream biomedicine and biology. Here we present a new QPI modality, coined multiplexed asymmetric-detection time-stretch optical microscopy (multi-ATOM) that captures and processes quantitative label-free single-cell images at ultrahigh throughput without compromising subcellular resolution.

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Image-based cellular assay advances approaches to dissect complex cellular characteristics through direct visualization of cellular functional structures. However, available technologies face a common challenge, especially when it comes to the unmet need for unraveling population heterogeneity at single-cell precision: higher imaging resolution (and thus content) comes at the expense of lower throughput, or vice versa. To overcome this challenge, a new type of imaging flow cytometer based upon an all-optical ultrafast laser-scanning imaging technique, called free-space angular-chirp-enhanced delay (FACED) is reported.

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Apart from the spatial resolution enhancement, scaling of temporal resolution, equivalently the imaging throughput, of fluorescence microscopy is of equal importance in advancing cell biology and clinical diagnostics. Yet, this attribute has mostly been overlooked because of the inherent speed limitation of existing imaging strategies. To address the challenge, we employ an all-optical laser-scanning mechanism, enabled by an array of reconfigurable spatiotemporally-encoded virtual sources, to demonstrate ultrafast fluorescence microscopy at line-scan rate as high as 8 MHz.

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We have previously shown that mice deficient in protein kinase C theta (PKCθ) have the ability to reject cardiac allografts, but are susceptible to tolerance induction. Here we tested role of B cells in assisting alloimmune responses in the absence of PKCθ. Mouse cardiac allograft transplantations were performed from Balb/c (H-2d) to PKCθ knockout (PKCθ(-/-)), PKCθ and B cell double-knockout (PBDK, H-2b) mice and wild-type (WT) C57BL/6 (H-2b) mice.

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Analyzing molecular biomarkers using blood is an important approach for clinical assessment of malignant glioma. We investigated a molecular proteomic biomarker-based approach for glioblastoma using patients' blood samples. The expression levels of a list of candidate proteins were quantified in plasma and serum samples from two different cohorts of patients with malignant glioma and normal controls.

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Objective: To assess the effects of different bariatric surgical procedures on the treatment of obesity and insulin resistance in high fat diet-induced obese (DIO) mice.

Background: Bariatric surgery is currently considered the most effective treatment for morbid obesity and its comorbidities; however, a systematic study of their mechanisms is still lacking.

Methods: We developed bariatric surgery models, including gastric banding, sleeve gastrectomy, Roux-en-Y gastric bypass (RYGB), modified RYGB (mRYGB) and biliopancreatic diversion (BPD), in DIO mice.

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Transforming growth factor beta (TGF-beta) is a master regulator of autocrine and paracrine signaling pathways between a tumor and its microenvironment. Decreased expression of TGF-beta type II receptor (TbetaRII) in stromal cells is associated with increased tumor metastasis and shorter patient survival. In this study, SILAC quantitative proteomics was used to identify differentially externalized proteins in the conditioned media from the mammary fibroblasts with or without intact TbetaRII.

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Unlabelled: Tumor microenvironment constitutes a reservoir for proteins released from tumor cells and the host, which can contribute significantly to tumor growth and invasion. This study aims to apply a method of combining in vivo microdialysis and proteomics to identify proteins in mammary tumor interstitial fluids, a major component of tumor microenvironment. In vivo microdialysis was performed in polyomavirus middle T antigen (PyVmT) transgenic mouse mammary tumors and age-matched control wild-type mammary glands.

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Congenital dyserythropoietic anemia I (CDA I) is a well-defined entity within the heterogeneous group of the CDAs. So far, most CDA cases were reported from Europe and Israel. A homozygous mutation of the CDAN1-gene was identified from a founder population observed in Bedouin tribes in Israel, and many different mutations in additional cases from Europe were reported.

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Objective: To investigate the regional spread of micrometastatic nodules in the mesorectum from low rectal cancer, and provide further pathological evidence to optimize radical resection procedure for rectal cancer.

Methods: A total of 62 patients with low rectal cancer underwent low anterior resection and total mesorectal excision (TME) was included in this study. Surgical specimens were sliced transversely and serial embedded blocks were made at 2.

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Objective: To explore the efficacy of autologous or allogeneic stem cell transplantation in adult patients with acute lymphoblastic leukemia (ALL) and investigate its relevant prognostic factors.

Methods: A total of 96 adult patients with ALL who had admitted to our hospital from November 1986 to June 2004 were followed up till February 28, 2005. They were divided into autologous stem cell transplantation (Auto-SCT) group (n = 56) and allogeneic stem cell transplantation (Allo-SCT) group (n = 40).

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Objective: To evaluate the effectiveness of chemotherapy (CT) and autologous hematopoietic stem cell transplantation (ASCT) as post-remission treatment for adult acute lymphoblastic leukemia (AL) patients.

Methods: Seventy-four ALL patients achieved first complete remission (CR(1)) with induction therapy, and then received early-stage sequential intensive consolidation chemotherapy. After that, 40 patients received chemotherapy (CT group) and 34 received ASCT (ASCT group) as post-remission treatment.

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Patients with chronic hepatitis C virus (HCV) infection have a significantly increased prevalence of type 2 diabetes mellitus compared to controls or HBV-infected patients. Moreover, the incidence rate of post-liver transplantation diabetes mellitus (PTDM) also appears to be higher among patients with HCV infection. PTDM is often associated with direct viral infection, autoimmune disorders, and immunosuppressive regimen.

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A novel cationic liposome modified with soybean sterylglucoside (SG) and polyethylene glycol-distearoylphosphatidylethanolamine (PEG-DSPE) as a carrier of antisense oligodeoxynucleotide (ODN) for hepatitis B virus (HBV) therapy was constructed. Characteristics of the cationic liposomes modified with SG and PEG (SG/PEG-CL) and their complexes with 15-mer phosphorothioate ODN (SG/PEG-CL-ODN complex) were investigated by incorporation efficiency, morphology, electrophoresis, zeta potentials, and size analysis. Antisense activity of the liposomes and ODN complexes was determined as hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in HepG2 2.

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Aim: In this study, a hepatocyte-specific targeting technology was developed by modifying cationic liposomes with soybean sterylglucoside (SG) and polyethylene glycol (PEG) (C/SG/PEG-liposomes).

Methods: The liposomal transfection efficiencies in HepG(2) 2.2.

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Objective: To examine the effects of analogs of pituitary adenylate cyclase activating polypeptide (PACAP)--PACAP6-27 (10, 100 microg/kg) and (4-Cl-D-Phe6, Leu17)VIP (10, 100 microg/kg) on the pancreata of normal rats and on the development of experimental acute pancreatitis.

Methods: Male Wistar rats were allocated into normal control groups, experimental acute pancreatitis groups and PACAP analog intervention groups. Acute pancreatitis was induced with s.

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Aim: To investigate the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis (AEP).

Methods: Fifty Wistar rats were randomly divided into control group (n = 10) and AEP group (n = 40). A model of AEP was established by subcutaneous injection of cerulein 5.

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Aim: Pituitary adenylate cyclase activating-peptide (PACAP) is a late member of the secretin/glucagon/vasoactive intestinal peptide (VIP) family of brain-gut peptides. It is unknown whether PACAP takes part in the development of acute pancreatitis and whether PACAP or its antagonists can be used to suppress the progression of acute pancreatitis. We investigated the actions of PACAP and its receptor antagonists in acute pancreatitis on rats.

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Aim: To investigate the biodistribution and the hepatocytes targeting of cationic liposome containing 3beta[N-( N',N'-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol) and surface-modified liposomes with sterylglucoside (SG) and polyethylene glycol-distearoylphosphatidylethanolamine (PEG-DSPE).

Methods: Cationic liposomes (CL) composed of DC-Chol and dipalmitoylphosphatidylcholine (DPPC), SG/PEG modified cationic liposome (SG/PEG-CL), both contained trace 3H-cholesterol (3H-Chol) as radiolabel, were prepared. The liposomes encapsulating 125I-labled antisense oligodeoxynucleotide (125I-asODN) (SG/PEG-CL-asODN) were also prepared.

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Objective: To evaluate the outcome of patients with de novo acute leukemia (AL, no AML-M(3)) in CR(1) undergone autologous hematopoietic stem cell transplantation (auto-HSCT) or HLA-identical sibling allogeneic HSCT (allo-HSCT).

Methods: Forty-six AL patients received allo-HSCT and 94 received auto-HSCT in CR(1). The conditioning regimens mainly consisted of TBICy, BuCy and MAC.

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Aim: To elucidate the role of COX-2 in the development of capillary leakage in rats with acute interstitial pancreatitis.

Methods: Rats with acute interstitial pancreatitis were induced by caerulein subcutaneous injection. Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene expression of COX-2 in pancreatic tissues, spectrophotometry was used to assay the parameters of acute pancreatitis such as the serum amylase and plasma myeloperoxidase, and determination of capillary permeability in the pancreas by quantifying the permeability index (PI) assisted response of pancreatic microvascular via intravital fluorescence microscope video image analysis system.

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Objective: To evaluate the efficacy of second allogeneic hematopoietic stem cell transplantation (allo-HSCT) for treatment of leukemia relapsed after first allo-HSCT.

Methods: Nine patients with relapsed acute leukemia (5 AML, 4 ALL) and one with chronic myelogenous leukemia (CML) who showed cytogenetic relapse after first allo-HSCT received second allo-HSCT. The median relapse time from the first allo-HSCT was 141 days.

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Objective: To investigate the role of inducible cyclooxygenase (COX-2) mRNA expression in local microvessels in rats with acute interstitial pancreatitis (AIP) induced by caerulein injection.

Methods: The reverse transcription polymerase chain reaction (RT-PCR) was used to detect COX-2 gene expression in pancreatic tissue. Parameters of acute pancreatitis, such as serum amylase (AMS) and plasma myeloperoxidase (MPO) activities, were assayed using spectrophotometry.

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Aim: To prepare fluorescein sodium (FS) cationic liposomes and investigate the influence of cationic lipid (DC-chol) and polyethylene glycol (PEG) with different molecule weight (MW) on cationic liposome incorporation efficiency, cellular delivery and fluidity of liposome membrane.

Methods: Using FS as a model material for encapsulation, the liposomes were prepared and separated (by sephadex G-50 1 cm x 20 cm column), and the liposome incorporation efficiencies was measured. The interaction between the FS and cationic liposomes was investigated by measuring the change of fluorescent spectrum.

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Objective: To study the interaction between 3beta-[N-(N', N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-chol), a cationic lipid, and antisense oligodeoxynucleotide (asODN), and the cytotoxicity to HepG(2) 2.2.15 cells and the inhibitory effects of asODN cationic liposomes on hepatitis B virus.

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