Comparison between the International Classification of Primary Care and the International Classification of Diseases Classifications in Primary Care in Korea.

BACKGROUND: The International Classification of Primary Care-2 (ICPC-2) is a classification method designed for primary care. Although previous studies have found that ICPC-2 is a useful tool for demonstrating the relationship between patients' expectations and health providers' diagnoses, its utility of ICPC-2 has yet to be fully studied in Korea. This study aimed to evaluate the practicality of ICPC-2 in Korean primary care. METHODS: The study was conducted at primary care clinics in Seoul and Gyeonggi areas from October to November 2015. Third-year family medicine residents examined and analyzed the medical records of patients who visited primary care physicians using ICPC-2, and the results were compared with those obtained using the International Classification of Diseases-10 (ICD-10) (Korean version: Korean Standard Classification of Diseases-7). RESULTS: A total of 26 primary care physicians from 23 primary care clinics participated in the study. Furthermore, 2,458 ICD-10 codes and 6,091 ICPC-2 codes were recorded from the data of 1,099 patients. The common disease codes were vasomotor and allergic rhinitis (J30), according to ICD-10, and acute upper respiratory infection (R74) in ICPC-2. Comparing disease status by body systems, the proportion of gastrointestinal disease with ICD-10 codes was significantly higher than that with ICPC-2 codes (P<0.001). Furthermore, patients with >4 diagnoses accounted for 36% of the ICD-10 classifications, whereas those with >4 diagnoses accounted for 4% of the ICPC-2 classifications. CONCLUSION: Introducing ICPC as a complementary means for diagnosing common diseases could be a practical approach in Korean primary care.

Pastable, Adhesive, Injectable, Nanofibrous, and Tunable (PAINT) Biphasic Hybrid Matrices as Versatile Therapeutic Carriers.

A critical challenge in many pharmaceutical fields is developing versatile adjuvant devices that can reduce the off-target delivery of therapeutic materials to target lesions. Herein, a biphasic hybrid fibrous system that can manipulate the spatial and temporal delivery of various therapeutic agents to target lesions by integrating multiple distinct systems and technologies such as fluffy coaxial electrospun polycaprolactone (PCL)/polystyrene (PS) fibers, cyclohexane-mediated leaching to remove PS layers selectively, amine display on PCL fibers, conjugation of naturally occurring adhesive gallol molecules onto hyaluronic acid (HA-g), and electrostatically complexing the aminated PCL fibers with the gallol-conjugated HA. In the context of "paintable" systems on target lesions, the resulting system is called a PAINT matrix (abbreviated according to the initial letter of its features: pastable, adhesive, injectable, nanofibrous, and tunable). Its viscoelastic property, which was attributed by coalescing aminated PCL fibers with viscous HA-g, enabled it to be noninvasively injected and fit into any cavity in the body with various morphologies, manually pasted on tissue surfaces, and adhered onto moisture-rich surfaces to ensure the secure delivery of therapeutics toward the target lesions. The PAINT matrix efficiently supplied immunomodulatory human neural stem cells (hNSCs) at rat hemisectioned spinal cord injury (SCI) sites and promoted both locomotive and sensory recovery in SCI models, presumably by protecting hNSCs against host immunosurveillance. The PAINT matrix will be broadly utilized for efficiently delivering therapeutics to difficult-to-reach target lesions by direct infusion or conventional biomaterial-mediated approaches due to their locations, wet surfaces, or complicated ambient environments.

AAVR-Displaying Interfaces: Serotype-Independent Adeno-Associated Virus Capture and Local Delivery Systems.

Interfacing gene delivery vehicles with biomaterials has the potential to play a key role in diversifying gene transfer capabilities, including localized, patterned, and controlled delivery. However, strategies for modifying biomaterials to interact with delivery vectors must be redesigned whenever new delivery vehicles and applications are explored. We have developed a vector-independent biomaterial platform capable of interacting with various adeno-associated viral (AAV) serotypes. A water-soluble, cysteine-tagged, recombinant protein version of the recently discovered multi-AAV serotype receptor (AAVR), referred to as cys-AAVR, was conjugated to maleimide-displaying polycaprolactone (PCL) materials using click chemistry. The resulting cys-AAVR-PCL system bound to a broad range of therapeutically relevant AAV serotypes, thereby providing a platform capable of modulating the delivery of all AAV serotypes. Intramuscular injection of cys-AAVR-PCL microspheres with bound AAV vectors resulted in localized and sustained gene delivery as well as reduced spread to off-target organs compared to a vector solution. This cys-AAVR-PCL system is thus an effective approach for biomaterial-based AAV gene delivery for a broad range of therapeutic applications.

Effects of Ionic Strength on Lateral Particle Migration in Shear-Thinning Xanthan Gum Solutions.

Viscoelastic fluids, including particulate systems, are found in various biological and industrial systems including blood flow, food, cosmetics, and electronic materials. Particles suspended in viscoelastic fluids such as polymer solutions migrate laterally, forming spatially segregated streams in pressure-driven flow. Viscoelastic particle migration was recently applied to microfluidic technologies including particle counting and sorting and the micromechanical measurement of living cells. Understanding the effects on equilibrium particle positions of rheological properties of suspending viscoelastic fluid is essential for designing microfluidic applications. It has been considered that the shear-thinning behavior of viscoelastic fluid is a critical factor in determining the equilibrium particle positions. This work presents the lateral particle migration in two different xanthan gum-based viscoelastic fluids with similar shear-thinning viscosities and the linear viscoelastic properties. The flexibility and contour length of the xanthan gum molecules were tuned by varying the ionic strength of the solvent. Particles suspended in flexible and short xanthan gum solution, dissolved at high ionic strength, migrated toward the corners in a square channel, whereas particles in the rigid and long xanthan gum solutions in deionized water migrated toward the centerline. This work suggests that the structural properties of polymer molecules play significant roles in determining the equilibrium positions in shear-thinning fluids, despite similar bulk rheological properties. The current results are expected to be used in a wide range of applications such as cell counting and sorting.

Safety and efficacy evaluations of an adeno-associated virus variant for preparing IL10-secreting human neural stem cell-based therapeutics.

Gene therapy technologies are inevitably required to boost the therapeutic performance of cell therapies; thus, validating the efficacy of gene carriers specifically used for preparing cellular therapeutics is a prerequisite for evaluating the therapeutic capabilities of gene and cell combinatorial therapies. Herein, the efficacy of a recombinant adeno-associated virus derivative (rAAVr3.45) was examined to evaluate its potential as a gene carrier for genetically manipulating interleukin-10 (IL10)-secreting human neural stem cells (hNSCs) that can potentially treat ischemic injuries or neurological disorders. Safety issues that could arise during the virus preparation or viral infection were investigated; no replication-competent AAVs were detected in the final cell suspensions, transgene expression was mostly transient, and no severe interference on endogenous gene expression by viral infection occurred. IL10 secretion from hNSCs infected by rAAVr3.45 encoding IL10 did not alter the transcriptional profile of any gene by more than threefold, but the exogenously boosted IL10 was sufficient to provoke immunomodulatory effects in an ischemic brain injury animal model, thereby accelerating the recovery of neurological deficits and the reduction of brain infarction volume. This study presents evidence that rAAVr3.45 can be potentially used as a gene carrier to prepare stem cell therapeutics.

Relationship Between Handgrip Strength and Pulmonary Function in Apparently Healthy Older Women.

OBJECTIVES: To investigate the relationship between handgrip strength and pulmonary function. DESIGN: Cross-sectional study of a representative sample of older Korean women. SETTING: The Korean National Health and Nutrition Examination Survey. PARTICIPANTS: Community-dwelling women aged 65 and older without chronic diseases or pulmonary disease (N=605). MEASUREMENTS: Handgrip strength was measured using a digital hand dynamometer, and pulmonary function was tested according to guidelines of the American Thoracic Society/European Respiratory Society using a spirometry system. Impaired pulmonary function was defined as a lower limit of normal (LLN) or less of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1). Odds ratios (ORs) and 95% confidence intervals (CIs) for impaired pulmonary function according to handgrip strength quartile were calculated using multiple logistic regression analysis. RESULTS: Mean FVC and FEV1 gradually increased in accordance with handgrip strength quartiles (all P <.001). After adjusting for age, body mass index, smoking status, alcohol ingestion, aerobic physical activity, resistance exercise, household income, and education level the odds of impaired pulmonary function were greater for participants in the first quartile of handgrip strength (≤19.25 kg) than for those in the fourth quartile (25.31-37.30 kg) (FVC LLN: OR=3.46, 95 % CI=1.52-7.88; FEV1 LLN: OR=2.62, 95 % CI=1.12-6.15). CONCLUSION: Handgrip strength was positively associated with pulmonary function in a dose-dependent manner. Given the health implications of pulmonary function, timely detection of weaker handgrip strength in older people may be useful in assessing potential pulmonary function impairment.

Korean Red Ginseng Protects Against Mitochondrial Damage and Intracellular Inflammation in an Animal Model of Type 2 Diabetes Mellitus.

Korean red ginseng (KRG), a heat-processed Korean ginseng (Panax ginseng C.A. Meyer), has been used as a traditional medicine for its beneficial effects on hyperglycemia. This study aimed to investigate whether the antidiabetic action of KRG in an animal model of type 2 diabetes mellitus (DM) is partly mediated by prevention of mitochondrial dysfunction and intracellular inflammation. Four-week-old C57BL/KsJ db/db mice (a genetic animal model of obese type 2 DM) and C57BL/KsJ db/+ mice were divided into three groups: db/+ mice (normoglycemic control group, n = 8), db/db mice (untreated DM group, n = 8), and db/db mice with KRG administration (KRG-treated DM group, n = 8). After 12 weeks, metabolic parameters of fasting blood glucose concentrations, hemoglobin A1c (HbA1c) level, insulin level, lipid profile, and leukocyte count were determined using high-performance liquid chromatography. Mitochondrial DNA (mtDNA) copy number and inflammatory marker (interleukin-6, cyclooxygenase-2, and C-reactive protein) expression levels were measured in skeletal muscle tissue using quantitative real-time PCR analysis. After 12 weeks of KRG treatment at 100 mg/kg, the fasting glucose, HbA1c, insulin, and low-density lipoprotein cholesterol concentrations were lower, whereas mtDNA copy numbers were higher in the KRG-treated DM group than in the untreated DM group. Compared with the untreated DM group, the messenger RNA expression levels of mitochondrial biogenesis-related transcription factors and inflammatory markers were lower in the KRG-treated DM group. In conclusion, KRG had a beneficial effect on the metabolic profile by preserving mitochondrial function and protecting against intracellular inflammation.

BiFACIAL ( Biomimetic Freestanding Anisotropic Catechol- Interfaces with Asymmetrically Layered) Films as Versatile Extracellular Matrix Substitutes.

Biological naïve extracellular matrices (ECMs) exhibit anisotropic functions in their physical, chemical, and morphological properties. Representative examples include anisotropic skin layers or blood vessels simultaneously facing multiphasic environments. Here, anisotropically multifunctional structures called BiFACIAL ( biomimetic freestanding anisotropic catechol- interfaces with asymmetrically layered) films were developed simply by contacting two polysaccharide solutions of heparin-catechol (Hep-C) and chitosan-catechol (Chi-C). Such anisotropic characters were due to controlling catechol cross-linking by alkaline pH, resulting in a trimodular structure: a rigid yet porous Hep-C exterior, nonporous interfacial zone, and soft/highly porous Chi-C interior. The anisotropic features of each layer, including the porosity, rigidity, rheology, composition, and ionic strength, caused the BiFACIAL films to show spontaneously biased stimuli responses and differential behaviors against biological substances (e.g., blood plasma). The films could be created in situ in live animals and imitated the structural/functional aspects of the representative anisotropic tissues (e.g., skin and blood vessels), providing valuable ECM-like platforms for the creation of favorable environments or for tissue regeneration or disease treatment by effectively manipulating cellular behaviors.

Targeting protein and peptide therapeutics to the heart via tannic acid modification.

Systemic injection into blood vessels is the most common method of drug administration. However, targeting drugs to the heart is challenging, owing to its dynamic mechanical motions and large cardiac output. Here, we show that the modification of protein and peptide therapeutics with tannic acid-a flavonoid found in plants that adheres to extracellular matrices, elastins and collagens-improves their ability to specifically target heart tissue. Tannic-acid-modified (TANNylated) proteins do not adsorb on endothelial glycocalyx layers in blood vessels, yet they penetrate the endothelium to thermodynamically bind to myocardium extracellular matrix before being internalized by myoblasts. In a rat model of myocardial ischaemia-reperfusion injury, TANNylated basic fibroblast growth factor significantly reduced infarct size and increased cardiac function. TANNylation of systemically injected therapeutic proteins, peptides or viruses may enhance the treatment of heart diseases.

Serum ferritin level is positively associated with insulin resistance and metabolic syndrome in postmenopausal women: A nationwide population-based study.

OBJECTIVE: Serum ferritin, a marker of iron metabolism, has recently emerged as a biomarker of chronic low-grade inflammation. After menopause, there is a remarkable increase in insulin resistance (IR) and metabolic syndrome (MetS), which is increasingly being viewed as an inflammatory disease. Thus, we examined the associations of serum ferritin with insulin resistance and MetS in postmenopausal women. METHODS: A nationwide cross-sectional study was conducted to examine the relationship between serum ferritin and IR and MetS in 2734 postmenopausal women using data from the 2010-2012 Korean National Health and Nutrition Examination Survey. The odds ratios (ORs) and 95% confidence intervals (CIs) for insulin resistance (HOMA-IR≥75th percentile, 3.04) and MetS were calculated using multiple logistic regression analyses across serum ferritin quartiles (Q1,≤36.25; Q2, 36.56-56.56; Q3, 56.57-85.98; and Q4≥85.99ng/ml). RESULTS: The mean values of most cardiometabolic variables tended to increase proportionally with serum ferritin quartiles. The proportion of women with IR and MetS significantly increased in accordance with serum ferritin quartiles. Compared to individuals in the lowest quartile, the ORs (95% CIs) in the highest quartile were 2.06 (1.23-3.45) for IR and 1.92 (1.44-2.55) for MetS after adjusting for age, cigarette smoking, alcohol intake, and regular exercise. CONCLUSION: Serum ferritin levels were positively and independently associated with IR and MetS in postmenopausal women. These findings suggest that serum ferritin level in postmenopausal women may help to identify the presence of IR and MetS.

Inverted Quasi-Spherical Droplets on Polydopamine-TiO2 Substrates for Enhancing Gene Delivery.

Devising efficient gene delivery systems is crucial to enhancing the therapeutic efficacy of gene-cell therapy approaches. Herein, inverted quasi-spherical (iQS) droplet systems, which enhance gene delivery efficiencies by reducing the path lengths of gene vectors, mediating motions of vectors at early stages, and raising the contact frequencies of vectors with cells, are developed by adopting the principle of 3D hanging-drop cell culture. Micrometer-sized polydopamine (pDA) holes are created on superhydrophobic titanium isopropoxide (TiO2 )-coated substrates by physical scraping; droplets are loaded on the pDA holes, and inversion of the substrate generates iQS droplets with large contact angles. Both human neural stem cells (hNSCs) and adeno-associated viral vectors are simultaneously incorporated into the iQS droplets to assess gene delivery efficiencies. The steep angles of iQS droplets and enhanced cell/vector contact frequencies facilitate the viral association with hNSCs and enhancing cell-cell interactions, thereby significantly promoting gene delivery efficiencies. Even with reduced viral quantities/exposure times and cell numbers, the iQS droplet systems elicit sufficient gene expression (i.e., interleukin-10). The ability of the iQS droplet systems to maximize beneficial gene delivery effects with minimal materials (e.g., medium, cells, and vectors) should enable their extensive use as a platform for preparing genetically stimulated cellular therapeutics.

Recombinant Adeno-Associated Virus Expressing Truncated IK Cytokine Diminishes the Symptoms of Inflammatory Arthritis.

IK can downregulate interferon-gamma-induced major histocompatibility complex (MHC) class II expression through the MHC class II transactivator, which suggests that IK can inhibit the interactions between immune cells. We delivered adeno-associated virus serotype 2 (AAV2) encoding the genes for truncated IK (tIK) or green fluorescent protein (GFP) to DBA1/J mice via intravenous injection. Seven weeks after injection, collagen-induced arthritis was induced in the AAV2-treated mice. AAV2-tIK injection reduced the severity of arthritis and the percentage of pathogenic Th17 cells compared with AAV2-GFP injection. These results suggest a novel gene therapy strategy for treatment of inflammatory arthritis.

Factors Positively Influencing Health Are Associated with a Lower Risk of Development of Metabolic Syndrome in Korean Men: The 2007-2009 Korean National Health and Nutrition Examination Survey.

BACKGROUND: The prevalence of metabolic syndrome (MetS) has risen rapidly worldwide, including in South Korea. Factors related to lifestyle are closely associated with the development of MetS. The aim of this study was to investigate the association between MetS and a number of factors positively influencing health, namely non-smoking, low-risk drinking, sufficient sleep, regular exercise, and the habit of reading food labels, among Korean men. METHODS: This cross-sectional study included 3,869 men from the 2007-2009 Korean National Health and Nutrition Examination Survey. Information on five factors positively influencing their health was obtained using a self-reported questionnaire. We categorized subjects into four groups, depending on the number of positive factors reported (group I, 0-1 factor; group II, 2 factors; group III, 3 factors; group IV, 4-5 factors). RESULTS: Men who reported a greater number of positive health factors had better laboratory and anthropometric values than men who reported fewer positive health factors. The prevalence of MetS was 29.1, 27.2, 20.7, and 14.6% in groups I to IV, respectively. Compared to group I, odds ratios (95% confidence intervals) for MetS were 0.96 (0.78-1.19) in group II, 0.67 (0.52-0.87) in group III, and 0.52 (0.35-0.76) in group IV, after adjusting for confounding factors. Odds ratios for abdominal obesity, glucose intolerance, and hypertriglyceridemia were statistically significant. CONCLUSION: A greater number of positive lifestyle factors influencing health were associated with a lower risk of developing MetS, in a nationally representative sample of Korean men.

Salt-Induced Electrospun Patterned Bundled Fibers for Spatially Regulating Cellular Responses.

Implementing patterned fibrous matrices can offer a highly valuable platform for spatially orchestrating hierarchical cellular constructs, specifically for neural engineering approaches, in which striated alignment or directional growth of axons are key elements for the functional recovery of damaged nervous systems. Thus, understanding the structural parameters of patterned fibrous matrices that can effectively promote neural growth can provide crucial clues for designing state-of-the-art tissue engineering scaffolds. To this end, salt-induced electrospun patterned fiber bundles (SiEP bundles) comprising longitudinally stacked multiple fibers were fabricated, and their capabilities of spatially stimulating the responses of neural cells, including PC12 cells, human neural stem cells (hNSCs), and dorsal root ganglia (DRG), were assessed by comparing them to conventional fibrous matrices having either randomly oriented fibers or individually aligned fibers. The SiEP bundles possessed remarkably distinctive morphological and topographical characteristics: multicomplexed infrastructures with nano- and microscale fibers, rough surfaces, and soft mechanical properties. Importantly, the SiEP bundles resulted in spatial cellular elongations corresponding to the fiber directions and induced highly robust neurite extensions along the patterned fibers. Furthermore, the residence of hNSCs on the topographically rough grooves of the SiEP bundles boosted neuronal differentiation. These findings can provide crucial insights for designing fibrous platforms that can spatially regulate cellular responses and potentially offer powerful strategies for a neural growth system in which directional cellular responses are critical for the functional recovery of damaged neural tissues.

Antiplatelet activity of epigallocatechin gallate is mediated by the inhibition of PLCgamma2 phosphorylation, elevation of PGD2 production, and maintaining calcium-ATPase activity.

We have previously reported that green tea catechins displayed a potent antithrombotic effect by inhibition of platelet aggregation. In the present study, the antiplatelet and antithrombotic activities of epigallocatechin gallate (EGCG), the major catechin derived from green tea, were extensively investigated. EGCG inhibited arterial thrombus formation and U46619-, collagen-, and arachidonic acid (AA)-induced washed rabbit platelet aggregation in a concentration-dependent manner, with IC50 values of 61 +/- 3, 85 +/- 4, and 99 +/- 4 microM, respectively. In line with the inhibition of collagen-induced platelet aggregation, EGCG revealed blocking of the collagen-mediated phospholipase (PL) Cgamma2 and protein tyrosine phosphorylation, and it caused concentration-dependent decreases of cytosolic calcium mobilization, AA liberation, and serotonin secretion. In addition, the platelet aggregation, intracellular Ca2+ mobilization, and protein tyrosine phosphorylation induced by thapsigargin, a Ca2(+)-ATPase pump inhibitor, were completely blocked by EGCG. Contrary to the inhibition of AA-induced platelet aggregation, EGCG failed to inhibit cyclooxygenase and thromboxane (TX) A2 synthase activities, but it concentration-dependently elevated AA-mediated PGD2 formation. In contrast, epigallocatechin (EGC), a structural analogue of EGCG lacking a galloyl group in the 3' position, slightly inhibited collagen-stimulated cytosolic calcium mobilization, but failed to affect other signal transductions as did EGCG in activated platelets and arterial thrombus formation. These results suggest that antiplatelet activity of EGCG may be attributable to its modulation of multiple cellular targets, such as inhibitions of PLCgamma2, protein tyrosine phosphorylation and AA liberation, and elevation of cellular PGD2 levels, as well as maintaining Ca2(+)-ATPase activity, which may underlie its beneficial effect on the atherothrombotic diseases.

Antiplatelet activity of [5-(2-methoxy-5-chlorophenyl)furan-2-ylcarbonyl]guanidine (KR-32570), a novel sodium/hydrogen exchanger-1 and its mechanism of action.

The antiplatelet effects of a novel guanidine derivative, KR-32570 ([5-(2-methoxy-5-chlorophenyl) furan-2-ylcarbonyl]guanidine), were investigated with an emphasis on the mechanisms underlying its inhibition of collagen-induced platelet aggregation. KR-32570 significantly inhibited the aggregation of washed rabbit platelets induced by collagen (10 microg/mL), thrombin (0.05 U/mL), arachidonic acid (100 microM), a thromboxane (TX) A2 mimetic agent U46619 (9,11-dideoxy-9,11-methanoepoxy-prostaglandin F2, 1 microM) and a Ca2+ ATPase inhibitor thapsigargin (0.5 microM) (IC50 values: 13.8 +/- 1.8, 26.3 +/- 1.2, 8.5 +/- 0.9, 4.3 +/- 1.7 and 49.8 +/- 1.4 microM, respectively). KR-32570 inhibited the collagen-induced liberation of [3H]arachidonic acid from the platelets in a concentration dependent manner with complete inhibition being observed at 50 microM. The TXA2 synthase assay showed that KR-32570 also inhibited the conversion of the substrate PGH2 to TXB2 at all concentrations. Furthermore, KR-32570 significantly inhibited the [Ca2+]i mobilization induced by collagen at 50 microM, which is the concentration that completely inhibits platelet aggregation. KR-32570 also decreased the level of collagen (10 microg/mL)-induced secretion of serotonin from the dense-granule contents of platelets, and inhibited the NHE-1-mediated rabbit platelet swelling induced by intracellular acidification. These results suggest that the antiplatelet activity of KR-32570 against collagen-induced platelet aggregation is mediated mainly by inhibiting the release of arachidonic acid, TXA2 synthase, the mobilization of cytosolic Ca2+ and NHE-1.

An antithrombotic agent, NQ301, inhibits thromboxane A2 receptor and synthase activity in rabbit platelets.

In previous studies we have reported that NQ301, a synthetic 1,4-naphthoquinone derivative, displays a potent antithrombotic activity, and that this might be due to antiplatelet effect, which was mediated by the inhibition of cytosolic Ca(2+) mobilization in activated platelets. In the present study, the effect of NQ301 on arachidonic acid cascade in activated platelets has been examined. NQ301 concentration-dependently inhibited washed rabbit platelet aggregation induced by collagen (10 microg/ml), arachidonic acid (100 microM) and U46619 (1 microM), a thromboxane A2 receptor agonist, with IC50 values of 0.60+/-0.02, 0.78+/-0.04 and 0.58+/-0.04 microM, respectively. NQ301 also produced a shift to the right of the concentration-effect curve of U46619, indicating a competitive type of antagonism on thromboxane A2/prostaglandin H2 receptor. NQ301 slightly inhibited collagen-induced arachidonic acid liberation. In addition, NQ301 potently suppressed thromboxane B2 formation by platelets that were exposed to arachidonic acid in a concentration-dependent manner, but had no effect on the production of prostaglandin D2, indicating an inhibitory effect on thromboxane A2 synthase. This was supported by thromboxane A2 synthase activity assay that NQ301 concentration-dependently inhibited thromboxane B2 formation converted from prostaglandin H2. Moreover, NQ301 concentration-dependently inhibited 12-hydroxy-5,8,10,14-eicosatetraenoic acid formation by platelets that were exposed to arachidonic acid. Taken together, these results suggest that NQ301 has a potential to inhibit thromboxane A2 synthase activity with thromboxane A2/prostaglandin H2 receptor blockade, and modulate arachidonic acid liberation as well as 12-hydroxy-5,8,10,14-eicosatetraenoic acid formation in platelets. This may also be a convincing mechanism for the antithrombotic action of NQ301.

Inhibition of PDGF beta-receptor tyrosine phosphorylation and its downstream intracellular signal transduction in rat aortic vascular smooth muscle cells by kaempferol.

Kaempferol, a flavonoid present in human diet and plants, has been known to show cardiovascular protection via its anti-oxidant activity. In this study, we have investigated the effect of kaempferol on the proliferation of primary cultured rat aortic vascular smooth muscle cells (VSMCs). Kaempferol significantly inhibited 50 ng/mL platelet-derived growth factor (PDGF)-BB-induced proliferation and [3H]-thymidine incorporation into DNA at concentrations of 5, 20 and 50 microM without any cytotoxicity. Kaempferol also inhibited the c-fos mRNA expression induced by PDGF-BB concentration-dependently. In addition, consistent with the inhibition of cell proliferation and c-fos mRNA expression, kaempferol inhibited the PDGF beta-receptor (Rbeta) phosphorylation in a concentration-dependent manner. Accordingly, the downstream signal transductions of PDGF-Rbeta such as ERK1/2, Akt and PLC-gamma1 phosphorylation were also inhibited by kaempferol in the same pattern. These findings suggest that, in addition to its anti-oxidant activity, the cardiovascular protective effect of kaempferol may be mediated, at least in part, by the suppression of VSMC proliferation, which is due to the inhibition of PDGF-Rbeta tyrosine phosphorylation and its downstream intracellular signal transduction.

BMS-191095, a cardioselective mitochondrial K(ATP) opener, inhibits human platelet aggregation by opening mitochondrial K(ATP) channels.

We evaluated the antiplatelet effects of two classes of ATP-sensitive potassium channel openers (K(ATP) openers) on washed human platelets, and the study's emphasis was on the role of mitochondrial K(ATP) in platelet aggregation. Collagen-induced platelet aggregation was inhibited in a dose dependent manner by lemakalim and SKP-450, which are potent cardio-nonselective K(ATP) openers, and also by cardioselective BMS-180448 and BMS-191095 (IC50: 1,130, >1,500, 305.3 and 63.9 microM, respectively), but a significantly greater potency was noted for the cardioselective K(ATP) openers. The latter two K(ATP) openers also inhibited platelet aggregation induced by thrombin, another important blood-borne platelet activator, with similar rank order of potency (IC50: 498.0 and 104.8 microM for BMS-180448 and BMS-191095, respectively). The inhibitory effects of BMS-191095 on collagen-induced platelet aggregation were significantly blocked by a 30-min pretreatment of platelets with glyburide (1 microM) or sodium 5-hydroxydecanoate (5-HD, 100 microM), a nonselective and selective mitochondrial K(ATP) antagonist, respectively, at similar magnitudes; this indicates the role of mitochondrial K(ATP) in the antiplatelet activity of BMS-191095. However, glyburide and 5-HD had no effect when they were added to the platelet cuvette immediately prior to the addition of BMS-191095. These findings indicate that cardioselective mitochondrial K(ATP) openers like BMS-191095 are able to exert cardioprotective effects in cardiac ischemia/reperfusion injury via dual mechanisms directed at the inhibition of platelet aggregation and the protection of cardiomyocytes, and both these mechanisms are mediated by mitochondrial K(ATP).

Antiplatelet activity of J78 (2-Chloro-3-[2'-bromo, 4'-fluoro-phenyl]-amino-8-hydroxy-1,4-naphthoquinone), an antithrombotic agent, is mediated by thromboxane (TX) A2 receptor blockade with TXA2 synthase inhibition and suppression of cytosolic Ca2+ mobilization.

We previously reported that J78 (2-chloro-3-[2'-bromo, 4'-fluoro-phenyl]-amino-8-hydroxy-1,4-naphthoquinone), a newly synthesized 1,4-naphthoquinone derivative, exhibited a potent antithrombotic effect, which might be due to antiplatelet rather than anticoagulation activity. In the present study, possible anti-platelet mechanism of J78 was investigated. J78 concentration-dependently inhibited rabbit platelet aggregation induced by collagen (10 microg/ml), thrombin (0.05 U/ml), arachidonic acid (100 microM), and U46619 (9,11-dideoxy-9,11-methanoepoxy-prostaglandin F(2); 1 microM), a thromboxane (TX) A(2) mimic, with IC(50) values of 0.32 +/- 0.01, 0.44 +/- 0.02, 0.50 +/- 0.04, and 0.36 +/- 0.02 microM, respectively. J78 also produced a shift to the right of the concentration-response curve of U46619, indicating an antagonistic effect on the TXA(2) receptor. J78 concentration-dependently inhibited collagen-induced arachidonic acid liberation. In addition, J78 potently suppressed TXA(2) formation by platelets that were exposed to arachidonic acid in a concentration-dependent manner but had no effect on the production of PGD(2), indicating an inhibitory effect on TXA(2) synthase. This was supported by a TXA(2) synthase activity assay that J78 concentration-dependently inhibited TXB(2) formation converted from PGH(2). Furthermore, J78 was also able to inhibit the [Ca(2+)](i) mobilization induced by collagen or thrombin at such a concentration that completely inhibited platelet aggregation. Taken together, these results suggest that the antiplatelet activity of J78 may be mediated by TXA(2) receptor blockade with TXA(2) synthase inhibition and suppression of cytosolic Ca(2+) mobilization.