Reduced Activity of Protein S in Plasma: A Risk Factor for Venous Thromboembolism in the Japanese Population.

The quantitative assay of protein S can help in rapidly identifying carriers of abnormal protein S molecules through a simple procedure (by determining the total protein S mass, total protein S activity, and protein S-specific activity in blood), without genetic testing. To clarify the relationship between venous thromboembolism (VTE) and protein S-specific activity, and its role in the diagnosis of thrombosis in Japanese persons, the protein S-specific activity was measured and compared between patients with thrombosis and healthy individuals. The protein S-specific activity of each participant was calculated from the ratio of total protein S activity to total protein S antigen level.

Significance of a Family-based Study of Hereditary Thrombosis: A Single-family Case Series of Protein C Deficiency.

Thrombophilia is a serious unpredictable complication caused by gene mutations, resulting in anticoagulant deficiencies. We herein report a single-family case series of protein C (PC) deficiency. Case 1 involved a Japanese man whose PC deficiency resulted in severe systemic thrombosis.

Crystallization of Human Erythrocyte Band 3, the anion exchanger, at the International Space Station "KIBO".

Band 3 mediates the Cl and HCO exchange across the red blood cell membrane and plays a pivotal role for delivering oxygen appropriately to metabolically active tissues. For understanding molecular mechanisms, it is essential to know the structure and function relationship. In terrestrial environments, however, nobody could make good quality crystals of Band 3 for the X-ray crystallographic study.

[A Case of Carcinomatous Pericarditis of Breast Cancer Successfully Treated with Intrapericardial Mitomycin C Instillations and Systemic Chemotherapy].

A 67-year-old woman who underwent left breast mastectomy and right breast partial mastectomy under the diagnosis of left breast cancer and suspected right breast cancer 10 years earlier was admitted because of dyspnea. Chest computed tomography revealed pericardial fluid accumulation. The patient was treated with pericardial drainage; thereby, 800 mL of bloody fluid was removed.

[Protein S-Specific Activity as an Indicator of Thrombophilia].

Approximately 50% of Japanese individuals who develop venous thrombosis have reduced activities of protein S, the major component of the Activated Protein C (APC) anticoagulant system. The significance of the measurement of protein S-specific activity and its practical use will be discussed.

Multianalyte Conventional Reference Material (MacRM): A Useful Tool for Nationwide Standardization of Laboratory Measurements for Medical Care-A Model Study in Japan.

Background: The Japanese Committee for Clinical Laboratory Standards (JCCLS) has developed a multianalyte conventional reference material (MacRM) for nationwide standardization of laboratory measurements.

Methods: To prepare the MacRM, pooled sera were obtained from healthy Japanese individuals. Target values of the pooled sera for 30 analytes were assigned on the basis of the measurement results of 45 certified clinical laboratories whose calibration was verified by measuring certified reference materials (CRMs) provided by the National Institute of Standards and Technology, the Institute for Reference Materials and Measurements, and JCCLS.

Crystal structure of the anion exchanger domain of human erythrocyte band 3.

Anion exchanger 1 (AE1), also known as band 3 or SLC4A1, plays a key role in the removal of carbon dioxide from tissues by facilitating the exchange of chloride and bicarbonate across the plasma membrane of erythrocytes. An isoform of AE1 is also present in the kidney. Specific mutations in human AE1 cause several types of hereditary hemolytic anemias and/or distal renal tubular acidosis.

Comparative Effects of Phosphoenolpyruvate, a Glycolytic Intermediate, as an Organ Preservation Agent with Glucose and N-Acetylcysteine against Organ Damage during Cold Storage of Mouse Liver and Kidney.

We evaluated the usefulness of phosphoenolpyruvate (PEP), a glycolytic intermediate with antioxidative and energy supplementation potentials, as an organ preservation agent. Using ex vivo mouse liver and kidney of a static cold storage model, we compared the effects of PEP against organ damage and oxidative stress during cold preservation with those of glucose or N-acetylcysteine (NAC). Lactate dehydrogenase (LDH) leakage, histological changes, and oxidative stress parameters (measured as thiobarbituric acid reactive substance and glutathione content) were determined.

Molecular basis of protein S deficiency in China.

Protein S (ProS) is a physiological inhibitor of coagulation with an important function in the down-regulation of thrombin generation. ProS deficiency is a major risk factor for venous thrombosis. This study enrolled 40 ProS-deficient probands to investigate the molecular basis of hereditary ProS deficiency in Chinese patients.

Phosphoenolpyruvate, a glycolytic intermediate, as a cytoprotectant and antioxidant in ex-vivo cold-preserved mouse liver: a potential application for organ preservation.

Objectives: The aim of this study was to examine the effect of phosphoenolpyruvate (PEP), a glycolytic intermediate, on organ damage during cold preservation of liver.

Methods: An ex-vivo mouse liver cold-preservation model and an in-vitro liver injury model induced by hydrogen peroxide in HepG2 cells were leveraged.

Key Findings: PEP attenuated the elevation of aminotransferases and lactate dehydrogenase leakage during organ preservation, histological changes and changes in oxidative stress parameters (measured as thiobarbituric acid reactive substance and glutathione content) induced by 72 h of cold preservation of the liver.

Activated protein C anticoagulant system dysfunction and thrombophilia in Asia.

Thrombophilia that is common among Caucasians is caused by genetic polymorphisms of coagulation factor V Leiden (R506Q) and prothrombin G20210A. Unlike that in Caucasians, thrombophilia that is common in the Japanese and Chinese involve dysfunction of the activated protein C (APC) anticoagulant system caused by abnormal protein S and protein C molecules. Approximately 50% of Japanese and Chinese individuals who develop venous thrombosis have reduced activities of protein S.

Phosphoenolpyruvic acid, an intermediary metabolite of glycolysis, as a potential cytoprotectant and anti-oxidant in HeLa cells.

This study examined the cytoprotective and anti-oxidative properties of phosphoenolpyruvic acid (PEP), a glycolysis metabolite with a high-energy phosphate group. PEP (0.1-10 mM) significantly attenuated the decrease in cell viability induced by hydrogen peroxide (H(2)O(2)) in HeLa cells in a dose-dependent manner.

Arg 901 in the AE1 C-terminal tail is involved in conformational change but not in substrate binding.

In our previous paper, we demonstrated that Arg 901 in the C-terminal tail of human AE1 (band 3, anion exchanger 1) had a functional role in conformational change during anion exchange. To further examine how Arg 901 is involved in conformational change, we expressed various Arg 901 mutants and alanine mutants of the C-terminal tail (from Leu 886 to Val 911) on the plasma membrane of Saccharomyces cerevisiae and evaluated the kinetic parameters of sulfate ion transport. As a result, Vmax decreased as the hydrophobicities of the 901st and peripheral hydrophilic residues increased, indicating that the hydrophobicity of the C-terminal residue is involved in the conformational change.

Topology models of anion exchanger 1 that incorporate the anti-parallel V-shaped motifs found in the EM structure.

We recently published the three-dimensional structure of the membrane domain of human erythrocyte anion exchanger 1 (AE1) at 7.5 Å resolution, solved by electron crystallography. The structure exhibited distinctive anti-parallel V-shaped motifs, which protrude from the membrane bilayer on both sides.

Resveratrol, a phytoestrogen found in red wine, down-regulates protein S expression in HepG2 cells.

Unlabelled: INTRODUATION: Resveratrol, a phytoestrogen present at a high concentration in red wine, has been reported to possess many health benefit effects that are protective against age-related diseases. Protein S (PS), an important anticoagulant factor in the protein C (PC) anticoagulant pathway, is mainly synthesized by hepatocytes, and its plasma level is decreased in high-estrogen conditions such as pregnancy and oral contraceptive use. The aim of this study was to investigate whether resveratrol affects PS expression in HepG2 cells.

Liquid phase immunoassays utilizing magnetic markers and SQUID magnetometer.

Background: Immunoassays are one main detection system used in the field of clinical chemistry. Recent developments of a new detection method utilizing a magnetic marker and magnetic sensor have enabled rapid and sensitive immunoassay without the need for bound/free (BF) separation.

Methods: Newly-synthesized conjugated avidin was used as the magnetic marker for quantitative analysis of human interleukin-8 (hIL-8) and immunoglobulin E (hIgE) in several media.

Mutation of His 834 in human anion exchanger 1 affects substrate binding.

Anion exchanger 1 (AE1 or band 3) is responsible for Cl(-)-HCO3(-) exchange on erythrocyte membrane. Previously, we showed that band 3 is fixed in an inward-facing conformation by specific modification of His 834 with DEPC, resulting in a strong inhibition of its anion transport activity. To clarify the physiological role of His 834, we evaluated the sulfate transport activities of various band 3 mutants: different mutants at His 834 and alanine mutants of peripheral residues around 834 (Lys 829-Phe 836) in yeast cell membranes.

Structure of the membrane domain of human erythrocyte anion exchanger 1 revealed by electron crystallography.

The membrane domain of human erythrocyte anion exchanger 1 (AE1) works as a Cl(-)/HCO(3)(-) antiporter. This exchange is a key step for CO(2)/O(2) circulation in the blood. In spite of their importance, structural information about AE1 and the AE (anion exchanger) family are still very limited.

Helical image reconstruction of the outward-open human erythrocyte band 3 membrane domain in tubular crystals.

The C-terminal membrane domain of erythrocyte band 3 functions as an anion exchanger. Here, we report the three-dimensional (3D) structure of the membrane domain in an inhibitor-stabilized, outward-open conformation at 18A resolution. Unstained, frozen-hydrated tubular crystals containing the membrane domain of band 3 purified from human red blood cells (hB3MD) were examined using cryo-electron microscopy and iterative helical real-space reconstruction (IHRSR).

[Activities of Japanese Committee for Clinical Laboratory Standards (JCCLS) toward standardization of laboratory medicine].

In this review, we summarize the laboratory medicine standardization activity of the Japanese Committee for Clinical Laboratory Standards (JCCLS). The JCCLS cooperates with the Joint Committee for Traceability in Laboratory Medicine (JCTLM). In the near future, we will accomplish a nationwide network system for the standardization of laboratory medicine (Patchwork Standardization-System).

[Standardization of laboratory medicine in Japan].

In this review, we summarize the standpoint of the Japanese Committee for Clinical Laboratory Standards (JCCLS) regarding the preparation of standard materials. The JCCLS cooperates with the Japan Association of Clinical Reagents Industries (JACRI), National Metrology Institute of Japan (NMIJ, AIST), and the Joint Committee for Traceability in Laboratory Medicine (JCTLM).