Publications by authors named "Weibo Ka"

The distal tubule and collecting duct in kidney regulate water homeostasis. TMOD1 is an actin capping protein that plays an important role in controlling the organization of actin filaments. In this study, we found TMOD1 was specifically expressed in distal tubules and collecting ducts.

View Article and Find Full Text PDF

The membrane skeleton of mature erythrocyte is formed during erythroid differentiation. Fluid shear stress is one of the main factors that promote embryonic hematopoiesis, however, its effects on erythroid differentiation and cytoskeleton remodeling are unclear. Erythrocyte tropomodulin of 41 kDa (E-Tmod41) caps the pointed end of actin filament (F-actin) and is critical for the formation of hexagonal topology of erythrocyte membrane skeleton.

View Article and Find Full Text PDF

Objective: To build a mathematical model to simulate the drug distribution accompanying with diffusion, distribution and clearance in the brain extracellular space (ECS).

Methods: Magnetic resonance imaging (MRI) technology was used to monitor changes in the signal-intensity-related tracer gadolinium-diethylene triamine pentaacetic acidm(Gd-DTPA), as an external drug which was injected into the rat brain, and then the mathematical model was built by using the data to establish the diffusion, distribution and clearance process of Gd-DTPA in the brain ECS. The model equation was resolved by Laplace transform.

View Article and Find Full Text PDF

Contrast media are the commonly used agents in radiology. However, because of their characteristics of high osmolality, high viscosity, and chemical toxicity, the administrations of contrast media have been shown to cause adverse effects especially on hemorheology in short time course. The present study is to find the effects of a non-ionic contrast medium, iopromide, on the hemorheology in long time course both in vitro and in vivo.

View Article and Find Full Text PDF

We previously isolated a sulfated polysaccharide-protein complex from Gekko swinhonis Guenther, a traditional Chinese medicine, and have demonstrated its direct anti-cancer effect on human hepatocellular carcinoma cell line SMMC-7721. Here we investigated the effects of Gekko sulfated polysaccharide-protein complex (GSPP) on the defective biorheological characters of dendritic cells (DCs) under SMMC-7721 microenvironment. Our findings have shown that the biorheological properties of DCs were severely impaired by SMMC-7721 microenvironment, including decreased cell deformability, migration, and electrophoresis mobility, increased osmotic fragilities, and changed organizations of cytoskeletal proteins.

View Article and Find Full Text PDF

It has been shown that 90% of tumors, including hematological malignant tumors and leukemia, have much higher levels of telomerase expression than normal cells. To investigate the effect of telomerase on leukemia cells, we transfected K562, a human erythroleukemia cell line with an antisense-hTERT (human telomerase reverse transcriptase) cDNA vector, and examined the biological and biophysical properties of the stably transfected cells (referred to as KAT). Un-transfected cells (K562) and cells transfected with the empty vector (referred to as KC) were used as controls.

View Article and Find Full Text PDF

The differentiation, maturation and functioning of Dendritic cells (DCs) are dynamic processes. This study investigated the changes of DCs' migration ability and biorheological properties during their differentiation. Transmigration assay showed that, DCs' migration rate was improved significantly as they differentiate (p < 0.

View Article and Find Full Text PDF

Dendritic cells (DCs), which are potent antigen presenting cells (APCs), are utilized to deliver the signals essential for the initiation of immune responses. In this study, we used an interdisciplinary approach to characterize the effect of K562 cells, a human chronic myeloid leukemia (CML) cell line, on the biomechanical characteristics and immune functions of DCs. When co-cultured with K562 cells, the biomechanical and immunological characteristics of immature DCs (imDCs) and mature DCs (mDCs) were severely impaired compared with controls.

View Article and Find Full Text PDF

Dichlorvos is an important insecticide used largely. Some studies have demonstrated that organophosphate pesticide has effects on erythrocyte membrane structures, which is critical to erythrocyte function and hemorheology. The aim of the present study was to explore the effect of oxidative stress on hemorheological changes during dichlorvos poisoning in rabbits.

View Article and Find Full Text PDF

Aim Of The Study: Gekko swinhonis Guenther has been used as an anti-cancer drug in traditional Chinese medicine for hundreds of years. Here we investigated the structural characterization and anti-cancer effects of sulfated polysaccharide-protein complex (GSPP) isolated from Gekko swinhonis Guenther.

Materials And Methods: The structure of GSPP was characterized by high performance liquid chromatography, gas chromatography, gas chromatography-mass spectrometry, beta-elimination reaction, and NMR spectroscopy.

View Article and Find Full Text PDF

Ryanodine receptors (RyRs) are a family of Ca2+ channel proteins that mediate the massive release of Ca2+ from the endoplasmic reticulum into the cytoplasma. In the present study, we manipulated the incorporation of RyR1 into RBC membrane and investigated its influences on the intracellular Ca2+ ([Ca2+](in)) level and the biomechanical properties in RBCs. The incorporation of RyR1 into RBC membranes was demonstrated by both immunofluorescent staining and the change of [Ca2+](in) of RBCs.

View Article and Find Full Text PDF

There is evidence that hyperlipidemia can induce hemorheological and microcirculatory disturbances. Myakuryu, a Chinese traditional medicine is efficacious in promoting lipid metabolism and protecting oxidative stress, but whether this drug can ameliorate rheologic disturbances caused by hyperlipidemia is still unknown. The present study was conducted to investigate the effects of myakuryu on hemorheological and microcirculatory disturbances induced by hyperlipidemia.

View Article and Find Full Text PDF

Erythroblasts were obtained from murine spleen. After cultured for 12 hr, the cells were divided into four groups with the use of the following cytokines in culture: EPO, EPO+SCF, EPO+IL-3, and EPO+IL-3+SCF. Cell proliferation assay was done.

View Article and Find Full Text PDF

After injecting VP16, MEL cells and MEL-TF19 cells into the body of mice, with those injected with the same dose of saline as the control group, we observed the mice for their blood pictures, histological changes of the liver and spleen, and the hemorheological indexes within 4 weeks. The results indicated that after injecting MEL cells, the mice entered into a pathological status similar to erythroleukemia, which had the following exhibitions: the tissue structures of the liver and spleen were damaged, a mass of proerythroblasts, basophil erythroblasts and polychromatophilic erythroblasts could be observed on the smears of the bone marrow and spleen, and the deformability and orientation ability of erythrocytes were both depressed. The pathogenicity of MEL-TF19 cells carrying TFAR19 gene was obviously lower than that of MEL cells, and the MEL-TF19 cells even lost their faintish pathogenicity under the apoptosis-inducing effect of the chemotherapeutic reagent.

View Article and Find Full Text PDF

Objectives: Previous investigations have shown that human wild-type p53 gene (WTp53) inhibits the growth of leukemia and tumor cells in vitro. In the present study, the authors used nude mice and examined the therapeutic role of p53 gene for erythroleukemia in vivo in the absence of MHC effects.

Methods: The nude mice were injected with murine erythroleukemia cells (MEL), MEL cells transfected with wild-type p53 gene (MEL-W), and MEL cells transfected with mutated p53 gene (MEL-M).

View Article and Find Full Text PDF

The generation and progress of tumors are accompanied with a marked suppression of human immune system. To explore the mechanisms by which tumors escape from immune recognition, we studied the influences of tumor microenvironment on differentiation of dendritic cells (DCs), which play an important role in tumor immunology, by biophysical and immunological methods. It was found that the cytokines derived from tumors caused an increase in osmotic fragility and a decrease in membrane fluidity of DCs, disordering and elevated expression levels of cytoskeleton, and changes of the gene transcriptional levels and energy status of the cells.

View Article and Find Full Text PDF

TRAIL can selectively induce rapid apoptosis of various types of tumor cells. We induced the expression of TRAIL in Jurkat cells, and measured the adhesion of cells to human umbilical vein endothelial cells (HUVECs) and laminin (LN) in a parallel plate flow chamber system and by using a colorimetric method. The apoptosis percentage, cycle distribution, intracellular Ca(2+) concentration, and adhesion molecule expression of the cells were detected by flow cytometry.

View Article and Find Full Text PDF

The aim of this research is to study the biochemical and biophysical properties of the precursor cells of mouse erythrocytes at different stages and the molecular mechanisms of their regulation. We investigated the degree of terminal differentiation of splenic erythroblasts obtained from mice during the acute phase of disease caused by the anemia-inducing FVAstrain of Friend virus. We analyzed the transcription and protein levels of alpha-globin, beta-globin (erythroid special protein) and GATA-1 (a special erythroid transcription factor).

View Article and Find Full Text PDF

Dendritic cells (DCs), which are the most efficient antigen-presenting cells (APCs) currently known, can be derived from CD14+ monocytes (DC predecessor cells) in vitro. Immature DCs actively take up antigens and pathogens, generate major histocompatability complex-peptide complexes, and migrate from the sites of antigen acquisition to secondary lymphoid organs to become mature dendritic cells that interact with and stimulate T-lymphocytes. During this process, the cells must undergo deformation to translocate through several barriers, including the basement membrane and interstitial connective tissue in the blood vessel wall.

View Article and Find Full Text PDF

We investigated the biomechanical properties of reticulocytes obtained from an animal model of hemolytic anemia induced by antibody injection. The hemorheological indices, membrane viscoelasticity, membrane fluidity, and the secondary structure of membrane proteins of the reticulocytes were monitored continuously during the course of their maturation into erythrocytes. The results indicate that reticulocytes had lower deformability, lower membrane fluidity, greater viscoelastic modulus and lesser proportions of alpha-helices and beta-sheets in protein secondary structures than mature erythrocytes.

View Article and Find Full Text PDF

The purpose of this study was to examine the changes of hemorheological properties of erythrocytes in the nude mice with erythroleukemia and the treatment effects of etoposide (VP16). Thirty mice were randomly divided into three groups: the control group (C group), injected with 1 ml saline solution, the MEL group (M group) injected with 1 ml MEL (murine erythroleukemia cell line) and the MEL + VP16 group (V group) injected with 1 ml MEL and from the 8th day after injection, 20 microl VP16 (1 microg/microl) was injected intraperitoneally every five days. One week after MEL injection, erythroblastic cells increased in the bone marrow and proerythroblasts were found in the peripheral blood, suggesting that erythroleukemia was induced.

View Article and Find Full Text PDF

TFAR19 is a novel apoptosis-related gene and can accelerate cell apoptosis in the presence of apoptosis inducements. Here, we studied the effects of TFAR19 on some biophysical properties of mouse erythroleukemia (MEL) cells and their molecular and structural basis. After transfected with TFAR19 and apoptosis inducement, MEL revealed a high cell membrane fluidity, a decrease in resynthesis of phospholipids, an increase in the proteins/nucleic acids ratio, a relatively orderly cytoskeleton network, an impaired deformability, a low integrin aM expression, and a decrease in adhesion to endothelial cells.

View Article and Find Full Text PDF

Dendritic cells (DC) are sentinels of the immune system. They and their precursors undergo complex migration to perform their function in vivo. Binding of DC to vascular endothelial cells in a flow field has not been investigated.

View Article and Find Full Text PDF

The purpose of this study was to examine the effects of Compound Dan-shen Root Dropping Pill (CDRDP) (Tasly Group, Tianjing, China) on hemorheology and biorheology of dogs suffering from hyperlipidemia induced by high-fat diet. Eighteen dogs were randomly divided into two groups: the high-fat diet group (H group); the control group (C group), fed with a standard laboratory diet. Six month later, six dogs in the H group were chosen as the drug-taking group (D group), to which CDRDP was administered, fed with the same diet as H group.

View Article and Find Full Text PDF

The changes in the cellular main components of the mouse erythroleukemia cell line MEL for TFAR19 gene transfection were studied by the technology of Fourier transform infrared spectroscopy (FTIR). Using the method of gene transfection with liposome, we obtained MEL-TF19 cell line, which stably carries TFAR19, a novel apoptosis-related gene. The expression of the gene on mRNA level was confirmed by RT-PCR.

View Article and Find Full Text PDF