Nitric oxide production by high molecular weight water-soluble chitosan via nuclear factor-kappaB activation

High molecular weight water-soluble chitosan (WSC), having an average molecular weight of 300000 Da and a degree of deacethylation over 90%, can be produced using a simple multi-step membrane separation process. In this study, the effect of WSC on the production of nitric oxide (NO) in RAW 264.7 macrophages was evaluated. Water-insoluble chitosan alone has been previously shown to exhibit in vitro stimulatory effect on macrophages NO production. However, WSC had no effect on NO production by itself. When WSC was used in combination with recombinant interferon-gamma (rIFN-gamma), there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of WSC on NO synthesis was shown 24 h after treatment with rIFN-gamma. The increased production of NO from rIFN-gamma plus WSC-stimulated RAW 264.7 macrophages was decreased by the treatment with N(G)-monomethyl-L-arginine (N(G)MMA). The increase in NO synthesis was reflected, as an increased amounts of inducible NO synthase protein. In addition, synergy between rIFN-gamma and WSC was mainly dependent on WSC-induced tumor necrosis factor-alpha (TNF-alpha) and nuclear factor-kappaB (NF-kappaB) activation. The present results indicate that the capacity of WSC to increase NO production from rIFN-gamma-primed RAW 264.7 macrophages is the result of WSC-induced TNF-alpha secretion via the signal transduction pathway of NF-kappaB activation.

Inhibition of tumor necrosis factor-alpha-induced apoptosis by Asparagus cochinchinensis in Hep G2 cells

A human hepatoma cell line, Hep G2 cells, is a reliable system for the study of alcohol-induced hepatotoxicity. In this study, we investigated the effect of an aqueous extract of Asparagus cochinchinensis(MERRIL) (Liliaceae) roots (ACAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. ACAE (1-100 microg/ml) dose-dependently inhibited the EtOH-induced tumor necrosis factor-alpha (TNF-alpha) secretion. ACAE (1-100 microg/ml) also inhibited the EtOH and TNF-alpha-induced cytotoxicity. Furthermore, we found that ACAE inhibited the TNF-alpha-induced apoptosis of Hep G2 cells. These results suggest that ACAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.

Effects of butylated hydroxyanisole and butylated hydroxytoluene on DNA adduct formation and arylamines N-acetyltransferase activity in PC-3 cells (human prostate tumor) in vitro

The effects of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) on the N-acetyltransferase (NAT) activity and DNA adduct formation in PC-3 cells (human prostate tumor) was studied. PC-3 cells were placed into tissue culture flasks and grown in an incubator as cytosols and intact cells. The BHA or BHT were added to the cytosols and intact cells. The NAT activity in cytosol and intact PC-3 cells were measured by HPLC assaying exhibited for the amounts of N-acetyl-2-aminofluorene and N-acetyl-p-aminobenzoic acid, 2-aminofluorene and p-aminobenzoic acid. The NAT activity in PC-3 cells and cytosols were inhibited by BHA or BHT in a dose-dependent manner; that is, the higher the concentrations of BHA or BHT the higher inhibition of NAT activity. The NAT values of K(m) and V(max) from PC-3 cells were also decreased by BHA or BHT in both cytosols and intact cells. The data also demonstrated concomitant exposure to BHA or BHT decreased AF-DNA adduct formation which was seen in the PC-3 cells. In addition, the formation of DNA adduct was decreased after BHA or BHT exposure. These findings suggested the usefulness of using human cultured PC-3 cells for assessing arylamine-induced DNA adduct formation. Furthermore, the findings illustrate how effectively BHA or BHT reduce the adduct formation.

CDNA cloning of chloroplast omega-3 fatty acid desaturase from Capsicum annuum and its expression upon wounding

A clone for a plastid omega-3 fatty acid desaturase (FAD) was isolated from a leaf cDNA library of hot pepper (Capsicum annuum L.). The nucleotide sequence of a 1,317 bp open reading frame in the CachFAD showed 80.9% homology with that of tobacco plant. It codes for a polypeptide of 438 amino acids with molecular mass of 50.5 kDa and a pI of 8.14. The CachFAD had a putative transit peptide for targeting the chloroplast. Genomic Southern hybridization indicated that it exists as small gene family. Northern hybridization revealed that its mRNA was present in leaves, but not in roots. Transcript levels in the leaves upon wounding increased rapidly to reach the first peak between 1-3 h, decreased thereafter and slightly increased at 24 h after wounding. The levels of linolenic acid (18:3) in wounded leaves also reached the first peak at 6 h, decreased thereafter and reached the second peak at 18 h. These results indicated that wounding not only enhanced the accumulation of the CachFAD mRNA but also increased the conversion of linoleic acid (18:2) to linolenic acid (18:3) in leaf lipids of hot pepper.

Dopa-responsive dystonia is induced by a dominant-negative mechanism

Dopa-responsive dystonia (DRD) is induced by a deficiency of GTP cyclohydrolase I (GCH) and has a postulated autosomal dominant inheritance with a low penetrance. G201E is a dominant DRD mutation. Recombinant G201E mutant protein possessed very low enzyme activity. When G201E was expressed in eukaryotic cells, only a small amount of GCH protein could be detected. In baby hamster kidney cells, G201E protein was synthesized normally but was degraded rapidly in pulse-chase experiments. More interestingly, G201E dramatically decreased the level of wild-type protein and GCH activity in cotransfection studies. Therefore, G201E exerts a dominant-negative effect on the wild-type protein, probably going through an interaction between them. We also showed that L79P but not R249S (a recessive DRD mutation) had a dominant-negative effect. Through the dominant-negative mechanism, a single mutation could decrease GCH activity to less than 50% of normal. This study not only explains the inheritance of DRD but also increases the understanding of genetic diseases associated with multiple subunit proteins.

Affinity purification and characterization of a cutinase from the fungal plant pathogen Monilinia fructicola (Wint.) honey

Trifluoromethyl ketones (TFK) are potent inhibitors of a variety of serine hydrolases. The TFK inhibitor, 3-(4-mercaptobutylthio)-1,1,1-trifluoro-2-propanone (MBTFP), was found to competitively inhibit cutinase activity (I50 = 9.4 x 10(-3)) from the fungal plant pathogen Monilinia fructicola and to serve as an effective affinity ligand for the purification of cutinases from culture filtrates. The TFK inhibitors, 3-n-octylthio-1,1,1-trifluoro-2-propanone (OTFP) and 3-n-pentylthio-1,1,1-trifluoro-2-propanone (PTFP), also inhibited cutinase activity with I50 values of 1.6 x 10(-6) and 2.3 x 10(-4) M, respectively. Buffer containing OTFP was the strongest eluant for cutinases of M. fructicola and provided the best purification factor and yield, although buffers containing OTFP, detergent, and salt were found to be effective for eluting cutinases bound to MBTFP-Sepharose. Buffer containing 0.5% Triton X-100 also selectively eluted cutinases from the affinity column. Two-dimensional electrophoretic analysis by SDS-PAGE and isoelectric focusing of the affinity-purified cutinase fraction indicated activity associated with proteins of pI 8.2 and molecular masses of approximately 18.6 and 20.8 kDa. These proteins hydrolyzed [3H]cutin and artificial substrates such as p-nitrophenylbutyrate and related esters, typical of other cutinases, but differ from previously characterized cutinases in molecular mass. The two low-molecular-weight proteins resolved by 2-D gel electrophoresis were subjected to in-gel digestion with Lys-C and the resulting peptide fragments were separated by Microbore-HPLC. The amino acid sequences of several internal peptide fragments had high homology with cutinase sequences from other fungi, particularly the plant pathogen Botrytis cinerea. Our study illustrates the potential of TFK ligands for the affinity purification of cutinases and indicates that the cutinases from M. fructicola have novel features warranting further study.

Glucose-6-phosphatase gene mutations in Taiwan Chinese patients with glycogen storage disease type Ia

Glycogen storage disease type Ia (GSD Ia) is caused by a deficiency of glucose-6-phosphatase (G6Pase) activity. Eighteen GSD Ia families were studied for G6Pase gene mutations. Thirty-two mutations were found in 36 GSD Ia chromosomes: 16 were 727 G-->T (44.44%); 13 were R83H (327 G-->T; 36.11%); 1 was 341delG; 1 was 933insAA; and 1 was 793 G-->T. The 727 G-->T and R83H mutations together accounted for 80.56% (29/36) of the GSD Ia chromosomes. These two mutations were easily examined by polymerase chain reaction-based methods, and the prenatal diagnosis of a non-affected fetus was successfully made. The 727 G-->T mutation is the predominant mutation in Japanese GSD Ia patients, but is rarely seen in Western counties. The 727 G-->T mutation is also the most prevalent mutation in Taiwan Chinese, although the incidence is not as high as in Japan.

Identification of the human homologue of mouse KIF4, a kinesin superfamily motor protein

A combination of RT-PCR with cDNA library screening led to the identification of the human homologue of murine KIF4 (mKIF4), a microtubule-based motor protein. The nucleotide sequence of human KIF4 (hKIF4) comprised part of the 5' untranslated region (UTR), a long open reading frame (ORF) encoding 1232 amino acids, and the entire 3' UTR. Homologies with mKIF4 were 82% and 85% for nucleotides and amino acids, respectively. A single transcript of 5. 0 kb was highly expressed in hematopoietic tissues including fetal liver, spleen, and thymus, and adult thymus and bone marrow. Comparison of the ORF with that of mKIF4 revealed some dissimilarities in the putative cargo binding domain which might affect binding specificities.

Enhanced guided bone regeneration by controlled tetracycline release from poly(L-lactide) barrier membranes

With the aim of providing effective periodontal therapeutic modality, drug-releasing membranes for guided tissue regeneration (GTR) were developed. As GTR membranes, biodegradable barrier membranes composed of porous poly(L-lactide) (PLLA) films cast on poly(glycolide) (PGA) meshes were fabricated using an in-air drying phase inversion technique. PLLA was dissolved in methylene chloride-ethylacetate mixtures, cast on knitted PGA mesh, and then air-dried. Tetracycline, which is used in periodontal therapy because of its antibacterial activity and tissue regenerating effects, including osteoblast chemotactic effect and anti-collagenolytic activity, was incorporated into the membranes by adding it to PLLA solutions. The guided bone regenerating potential of tetracycline-loaded membranes was evaluated using release kinetics both in vitro and in vivo, biodegradation tests, and cell attachment tests. Homogeneous pores were generated both at the surface and in a sublayer of the membranes. The release kinetics of tetracycline depended mainly upon the hydrophilicity of tetracycline and the porosity of the membrane. The release rate further could be controlled by loaded drug contents. The release of tetracycline was appropriate for maintaining anti-microbial activity and for its tissue-regenerating potential. The membranes retained a proper degradation property, maintaining their mechanical integrity for the barrier function for 4 weeks. Tetracycline-loaded membranes induced increased cell attachment levels compared with those of unloaded membranes. Tetracycline-loaded membranes markedly increased new bone formation in rat calvarial defects and induced bony reunion after 2 weeks of implantation. These results suggest that tetracycline-loaded PLLA membranes potentially enhance guided tissue regenerative efficacy.

Radiation-induced grafting of methylmethacrylate onto ultrahigh molecular weight polyethylene and its adhesive characteristics

The surface of ultrahigh molecular weight polyethylene (UHMWPE) was modified by radiation-grafting methylmethacrylate (MMA) in the presence of sulfuric acid and metallic salt to increase bonding strength with polymethylmethacrylate. The effect of the addition of metallic salts and sulfuric acid on the radiation grafting reaction was investigated when MMA was grafted to the irradiated UHMWPE. The adhesive characteristics with the grafting yield were investigated using conventional acrylic bone cement based on poly(methyl methacrylate) [PMMA]. The results showed that the inclusion of an FeSO4 . 7H2O and sulfuric acid in MMA grafting solutions was extremely beneficial and led to a most unusual synergistic effect, while CuSO4 . 5H2O led to a detrimental effect. The tensile bonding strength between UHMWPE and PMMA sheet increased remarkably with an increased grafting yield on UHMWPE surfaces.

Alveolar type II cell abnormalities and peroxide formation in lungs of rats given IL-1 intratracheally

Acute lung injury (ALI) is characterized by increased lung levels of proinflammatory cytokines, inflammation, oxidative stress, edema, and impaired gas exchange. Notably, ALI patients also exhibit pulmonary surfactant abnormalities, including increased levels of phospholipids in their lung lavages. In the present study, to assess early alterations of the lung surfactant system in ALI, we induced inflammation and acute lung injury in rats by administering interleukin-1alpha (IL-1) intratracheally. Five h after IL-1 instillation, we examined lung tissue ultrastructure by electron microscopy using both routine staining methods and cerium chloride staining to localize hydrogen peroxide (H2O2) histologically. We also measured lung lavage phospholipid levels, lung tissue gamma-glutamyl transpeptidase (GGT) activities (a marker of oxidative stress), and arterial blood oxygen tensions. We observed that lungs of rats given IL-1 intratracheally had increased neutrophil accumulation, increased H2O2 production, and increased alveolar type II (ATII) pneumocyte ultrastructural abnormalities compared to rats given saline intratracheally. Intratracheal instillation of IL-1 also increased phospholipid levels in the bronchoalveolar lavage (BAL), possibly as a consequence of the abnormal discharge of lamellar bodies into the alveolar lumen. In addition, IL-1-insuffated rats had increased lung GGT levels and impaired blood oxygenation compared to saline-insufflated rats. Treatment with mepacrine decreased lung neutrophil accumulation, ultrastructural lung abnormalities, lung lavage phospholipid levels, lung tissue GGT levels, and blood oxygenation impairment in rats given IL-1 intratracheally, suggesting a possible relationship between these events. Our results indicate that IL-1-induced acute lung injury in rats is marked by neutrophil-dependent oxidative stress, ATII cell defects, abnormal discharge of lamellar body phospholipids, and impaired blood oxygenation.

Anti-angiogenic activity of torilin, a sesquiterpene compound isolated from Torilis japonica

Torilin is a sesquiterpene compound purified from fruits of Torilis japonica (Umbelliferae). In this study, we demonstrated the anti-angiogenic activity of torilin using in vivo and in vitro assay systems. Torilin decreased both neovascularization of chick embryos in the chorioallantoic membrane assay and basic fibroblast growth factor-induced vessel formation in the mouse Matrigel plug assay. Torilin also reduced the proliferation and tube formation of human umbilical vein endothelial cells. In addition, the concentrated conditioned media obtained from torilin-treated HepG2 human hepatoblastoma cells blocked the angiogenic activation of torilin-untreated concentrated conditioned media, indicating that torilin may have an inhibitory effect on tumor-induced angiogenesis. To determine what molecules were involved in the anti-angiogenic activity, we examined the expression of hypoxia-inducible angiogenic factors in torilin-treated HepG2 cells. Torilin significantly down-regulated the expression of hypoxia-inducible vascular endothelial growth factor and insulin-like growth factor-II. Taken together, our data suggest that torilin may be a strong angiogenic inhibitor with the ability to decrease tube formation of vascular endothelial cells and to reduce expression of angiogenic factors of tumor cells.

Controlled release of platelet-derived growth factor-BB from chondroitin sulfate-chitosan sponge for guided bone regeneration

Platelet-derived growth factor-BB (PDGF-BB) releasing porous chondroitin-4-sulfate (CS)-chitosan sponge was designed with an aim of controlling growth factor delivery in order to improve bone formation. Porous CS-chitosan sponge was fabricated by freeze drying and crosslinking aqueous CS-chitosan solution. PDGF-BB was incorporated into the CS-chitosan sponge by soaking CS-chitosan sponge into the PDGF-BB solution. CS-chitosan sponge retained a porous structure with a 150-200-microm pore diameter that was suitable for cellular migration and osteoid ingrowth. Release rate of PDGF-BB could be controlled by varying the composition of CS in the sponge or initial loading content of PDGF-BB. CS-chitosan sponge induced increased osteoblast migration and proliferation as compared with chitosan sponge alone. Furthermore, the release of PDGF-BB from CS-chitosan sponge significantly enhanced osteoblast proliferation. These results suggest that PDGF-BB-releasing CS-chitosan sponge may be beneficial to enhance bone cell adaptation and regenerative potential when applied in wound sites.

Platelet-activating factor contributes to acute lung leak in rats given interleukin-1 intratracheally

Lung lavage fluid of patients with acute lung injury (ALI) has increased levels of interleukin-1 (IL-1) and neutrophils, but their relationship to the lung leak that characterizes these patients is unclear. To address this concern, we investigated the role of the neutrophil agonist platelet-activating factor [1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (PAF)] in the development of the acute neutrophil-dependent lung leak that is induced by giving IL-1 intratracheally to rats. We found that PAF acetyltransferase and PAF activities increased in lungs of rats given IL-1 intratracheally compared with lungs of sham-treated rats given saline intratracheally. The participation of PAF in the development of lung leak and lung neutrophil accumulation after IL-1 administration was suggested when treatment with WEB-2086, a commonly used PAF-receptor antagonist, decreased lung leak, lung myeloperoxidase activity, and lung lavage fluid neutrophil increases in rats given IL-1 intratracheally. Additionally, neutrophils recovered from the lung lavage fluid of rats given IL-1 intratracheally reduced more nitro blue tetrazolium (NBT) in vitro than neutrophils recovered from control rats or rats that had been given WEB-2086 and then IL-1. Histological examination indicated that the endothelial cell-neutrophil interfaces of cerium chloride-stained lung sections of rats given IL-1 contained increased cerium perhydroxide (the reaction product of cerium chloride with hydrogen peroxide) compared with lungs of control rats or rats treated with WEB-2086 and then given IL-1 intratracheally. These in vivo findings were supported by parallel findings showing that WEB-2086 treatment decreased neutrophil adhesion to IL-1-treated cultured endothelial cells in vitro. We concluded that PAF contributes to neutrophil recruitment and neutrophil activation in lungs of rats given IL-1 intratracheally.

Antithrombotic effect of rutaecarpine, an alkaloid isolated from Evodia rutaecarpa, on platelet plug formation in in vivo experiments

In this study, platelet thrombi formation was induced by irradiation of mesenteric venules with filtered light in mice pretreated intravenously with fluorescein sodium. Rutaecarpine (200 microg/g) significantly prolonged the latent period of inducing platelet plug formation in mesenteric venules when it was intravenously injected. Rutaecarpine (200 microg/g) prolonged occlusion time by approximately 1.5-fold (control 127 +/- 29 vs. taecarpine 188 +/- 23 s). Furthermore, aspirin (250 microg/g) also showed a similar prolongation of the occlusion time in this experiment. On a molar basis, rutaecarpine was approximately twofold more potent than aspirin at prolonging the occlusion time. Furthermore, rutaecarpine was also effective in reducing the mortality of ADP-induced acute pulmonary thromboembolism in mice when administered intravenously at doses of 25 and 50 microg/g. Intravenous injection of rutaecarpine (50 microg/g) significantly prolonged the bleeding time by approximately 1.5-fold compared with normal saline in the severed mesenteric arteries of rats. Continuous infusion of rutaecarpine (5 microg/g/min) also significantly increased the bleeding time 1. 5-fold, and the bleeding time returned to baseline within 60 min after cessation of rutaecarpine infusion. These results suggest that rutaecarpine has an effective anti-platelet effect in vivo and that it may be a potential therapeutic agent for arterial thrombosis, but it must be assessed further for toxicity.

Analysis of ultrahigh molecular weight polyethylene failure in artificial knee joints: thermal effect on long-term performance

The mechanism resulting in damage to and failure of ultrahigh molecular weight polyethylene (UHMWPE) tibial inserts was investigated on clinically retrieved components. The severity of the subsurface damage increased with the length of time that the component had been implanted. A theoretical analysis was developed to account for the generation of subsurface damage based on a heat transfer model. Friction generates surface heat during articulation of total knee systems. Due to the cooling effect of body fluid on the surface, the rise in temperature on the UHMWPE surface is lower than that below the surface. The peak temperature was estimated to occur on a plane positioned about 1 to 2 mm below the surface. This result was similar to the bulk temperature variation observed during in vivo and in vitro studies by other investigators. Although the difference in temperature on and below the surface is only a few degrees, the thermal effect becomes apparent after a long time and may be explained by the viscoelastic behavior of polymers: the temperature-time equivalence. It is therefore suggested that this thermal effect is another contributory factor to material damage, in addition to high stress and oxidative degradation (in appropriate cases). Therefore, any technological efforts aimed at improving the performance of artificial joint prostheses should minimize the thermal effects at the subsurface of the articular components.

Racial differences in the prevalence of ulcerative colitis and Crohn's disease in Singapore

BACKGROUND

The aim of this study was to determine the prevalence rates of inflammatory bowel disease in the different races in Singapore.

METHODS

The patients studied consisted of 58 people with an established diagnosis of ulcerative colitis (UC) and Crohn's disease (CD) as determined by a combination of clinical, radiological, endoscopic and histological criteria. The patients were residents of a well-defined geographical area in the northern part of Singapore and had been referred to the single regional hospital. Epidemiological data including sex, age, ethnicity, family history and disease type and extent were collected from case records and patient interviews.

RESULTS

There were 37 UC and 21 CD patients. Of the patients with UC, 67.5% were Chinese, 13.5% were Malay and 19% were Indian. The CD group consisted of 81% Chinese, 9.5% Malay and 9.5% Indian patients. The study population from which the patients were drawn was approximately 0.5 million in size.

CONCLUSIONS

The overall prevalence of UC was 6 per 100,000 and of CD was 3.6 per 100,000 in Singapore. There were disproportionately more Indians suffering from UC, with a prevalence of 16.2 per 100,000 in comparison with six per 100,000 for Chinese and seven per 100 000 for Malays. The relative risk of UC in Indians is 2.9-fold greater than for the Chinese (CI= 1.25-6.7) which was statistically significant. This trend was not seen for CD.

Racial differences in the prevalence of ulcerative colitis and Crohn's disease in Singapore

BACKGROUND

The aim of this study was to determine the prevalence rates of inflammatory bowel disease in the different races in Singapore.

METHODS

The patients studied consisted of 58 people with an established diagnosis of ulcerative colitis (UC) and Crohn's disease (CD) as determined by a combination of clinical, radiological, endoscopic and histological criteria. The patients were residents of a well-defined geographical area in the northern part of Singapore and had been referred to the single regional hospital. Epidemiological data including sex, age, ethnicity, family history and disease type and extent were collected from case records and patient interviews.

RESULTS

There were 37 UC and 21 CD patients. Of the patients with UC, 67.5% were Chinese, 13.5% were Malay and 19% were Indian. The CD group consisted of 81% Chinese, 9.5% Malay and 9.5% Indian patients. The study population from which the patients were drawn was approximately 0.5 million in size.

CONCLUSIONS

The overall prevalence of UC was 6 per 100,000 and of CD was 3.6 per 100,000 in Singapore. There were disproportionately more Indians suffering from UC, with a prevalence of 16.2 per 100,000 in comparison with six per 100,000 for Chinese and seven per 100 000 for Malays. The relative risk of UC in Indians is 2.9-fold greater than for the Chinese (CI= 1.25-6.7) which was statistically significant. This trend was not seen for CD.

Assignments of the tyrosinase related protein-1 and -2 genes to human chromosome bands 9p23 and 13q32.1 by in situ hybridization

To determine the precise chromosomal localization of tyrosine related protein-1 and -2 (TRP-1 and TRP-2) genes by fluorescence in situ hybridization, we used DNAs isolated from human bacterial artificial chromosome clones. They contain genomic sequences with approximately 120 kb inserts for TRP-1 and TRP-2. The TRP-1 and TRP-2 genes were assigned to human chromosome bands 9p23 and 13q32.1, respectively. These results confirmed the previously mapped location for the TRP-1 gene and more precisely located the TRP-2 gene, which had previously been mapped to chromosome 13q31-q32.

Reduced IL-2 but elevated IL-4, IL-6, and IgE serum levels in patients with cerebral infarction during the acute stage

Cytokines in the central nervous system (CNS) may play an important role in functioning as intercellular signals that orchestrate the response to injury. Whether this is a cause or result of the brain disease process is uncertain. We investigated IFN-gamma, IL-2, IL-4, IL-6, and IgE in the sera of 38 patients with cerebral infarction during the acute stage and 10 normal controls using an originally devised sensitive sandwich enzyme-linked immunosorbent assay (ELISA). We found that serum levels of IL-2 derived from T helper 1 (Th1) cells were slightly reduced in patients with cerebral infarction, whereas serum levels of IL-4 and IL-6 derived from Th2 cells were elevated significantly. IL-4 induces synthesis of IgE in human B cells. Endogenous IL-6 plays an obligatory role in IL-4-dependent human IgE synthesis. We observed that serum IgE levels were elevated significantly in patients with cerebral infarction. However, serum IFN-gamma levels were not elevated significantly in cerebral infarction patients. These findings suggest that elevated IL-4, IL-6, and IgE levels in the human serum may be an important factor in cerebral infarction during the acute stage. Decrease of IL-2 levels in the serum of patients with cerebral infarction may be a regulatory mechanism.

The antihypertensive and cardioprotective effects of (-)-MJ-451, an ATP-sensitive K(+) channel opener

ATP-sensitive K(+) (K(ATP)) channel openers have been shown to be a potential class of therapeutic agents for the control of cardiovascular diseases, including angina, arrhythmias, and hypertension. In this study, the pharmacological activity of 6-cyano-3S,4R-dihydro-2, 2-dimethyl-2H-3-hydroxy-4-[5S-(1-hydroxymethyl)-2-oxo-1-pyrrolidinyl] -1-benzopyran ((-)-MJ-451), a synthetic K(ATP) opener, was evaluated in anesthetized rat models and in isolated rat thoracic rings. Results demonstrated that intravascular injection of (-)-MJ-451 (0. 02, 0.05 and 0.1 mg/kg) produced an immediate, dose-related reduction in mean arterial blood pressure in anesthetized spontaneously hypertensive rats (SHR), which persisted for more than 3 h and was not accompanied by reflex tachycardia. The hemodynamic changes were completely abolished by pretreatment with glibenclamide (4 mg/kg, i.v. bolus), a selective K(ATP) channel blocker. In isolated thoracic aorta, (-)-MJ-451 (10 nM-3 microM) produced a concentration-dependent vasodilator effect on the phenylephrine (0.3 microM)-induced vasoconstriction. Moreover, (-)-MJ-451 relaxed the thoracic aorta contracted by low (5, 20 and 30 mM), but not high (40 and 60 mM) concentrations of extracellular potassium. In addition, (-)-MJ-451 showed cardioprotective effects in the rat model of 45-min left coronary artery occlusion followed by 1-h reperfusion. In myocardial ischemia, pretreatment with (-)-MJ-451 (2, 5 and 10 microg/kg, i.v. bolus) significantly reduced the incidence of ventricular fibrillation and the mortality, also reducing the total number of ventricular premature contractions, total duration of ventricular tachycardia and ventricular fibrillation. A significant reduction in infarct size was noted in three (-)-MJ-451 (2, 5 and 10 microg/kg)-treated groups. Also, the cardioprotective effects of (-)-MJ-451 were virtually abolished by pretreating the rats with glibenclamide (4 mg/kg, i.v. bolus). In conclusion, (-)-MJ-451, through opening the K(ATP) channel, exerted antihypertensive and cardioprotective effects. Therefore, it is suggested that (-)-MJ-451 has potential in the treatment of hypertension or acute myocardial infarction.

Scanning laser polarimetry in evaluation of retinal nerve fiber layer thickness for normal Taiwanese

Scanning laser polarimetry has been used recently for the measurement of retinal nerve fiber layer (RNFL) thickness, taking advantage of the birefrigence of the RNFL. We observe the RNFL with the instrument and try to find out a set of normal basic values of the RNFL thickness for clinical comparison. One hundred normal volunteers of different age groups were recruited for this study. There are 44 males and 56 females with a mean (1SD) age of 36.17(14.77) years. Three consecutive 15-degree polarimetric maps were acquired for each subject. RNFL thickness measurements were obtained at 1.75 disc diameters ring from the optic nerve. Four 90-degree quadrants were identified. As a result, the average of RNFL thickness is 90.69 (20.20) microns in the superior quadrant, 80.45 (17.4) microns in the inferior quadrant, 59.28 (15.37) microns in the nasal quadrant, and 48.98 (15.72) microns in the temporal quadrant with a mean thickness value of 69.86 (13.97) microns. Superior and inferior quadrants showed a comparatively thicker nerve fiber layer than nasal and temporal quadrants. The temporal quadrant was always the lowest. The axial length does not affect the RNFL thickness and no significant difference between males and females exists. However, an obvious inverse linear correlation between age and the RNFL thickness in all quadrants is found. The average RNFL thickness decreased with age by 0.26 micron per year. (R2 = 0.081, p-value = 0.004). When compared with the normal range, age-match would be necessary.

Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)/poly(epsilon-caprolactone) (PCL) amphiphilic block copolymeric nanospheres. II. Thermo-responsive drug release behaviors

Amphiphilic block copolymers composed of relatively hydrophilic PEO-PPO-PEO block copolymer (Pluronic) and poly (epsilon-caprolactone) with hydrophobic character were synthesized by ring-opening polymerization of epsilon-caprolactone in the presence of PEO-PPO-PEO block copolymer using stannous octoate as a catalyst. Pluronic/PCL block copolymeric nanospheres with core-shell structure were prepared by dialysis method. They showed the average diameter of 116-196 nm depending on the type of copolymer. All the nanosphere samples exhibited a narrow size distribution. The critical micelle concentrations of Pluronic/PCL amphiphilic block copolymers determined by fluorescence spectroscopy were lower than that of the common low molecular weight surfactant. Their core-shell structure was confirmed by 1H NMR spectroscopy. Pluronic/PCL block copolymeric nanospheres exhibited the reversible change of size depending on the temperature. Release behaviors of indomethacin from Pluronic/PCL block copolymeric nanospheres also showed temperature dependence and a sustained release pattern. In addition, cytotoxicity test using an MTT assay method revealed that these indomethacin-loaded Pluronic/PCL nanospheres could remarkably reduce the cell damage compared with the unloaded free indomethacin.

History of the Korean GLPs and the activities and perspectives of the Korean Society of GLP

The Korean Society of Good Laboratory Practice (KSGLP) was established Dec. 10, 1998. The objectives of the KSGLP are to enhance the quality of domestic studies and the level of GLP compliance, in safety testing, and to promote information exchange among its members. The activities of KSGLP include: offering workshops and symposiums, linking with related governmental organizations, collecting GLP related information and providing the information to the related organizations, building international networks to collect information and to establish relationship, developing training materials and publishing periodicals, and other business necessary to achieve the objectives of the KSGLP. The KSGLP achieved its goals within a short period of time by offering workshops and symposia, and by providing important GLP related information in newspapers or via the KSGLP's internet homepage (www.ksglp.or.kr). The main role of the KSGLP will be to disseminate GLP technology nationwide. The KSGLP would like to help many labs that are preparing their facilities for GLP compliance. Further, the KSGLP is hoping to share GLP experiences with other members.