Loss of heterozygosity on chromosome 22q and 17p correlates with aggressiveness of meningiomas

According to reported cytogenetic studies, there is a significant association between chromosomal aberrations and aggressiveness in meningiomas. With the method of restriction fragment length polymorphism analysis (RFLP), we examined tumor specific LOH on chromosome 17p and 22q in 30 cases of intracranial meningiomas. There were eight cases of meningiomas with aggressive characteristics, such as invasive meningioma, malignant meningioma, hemangiopericytic meningioma, and multiple meningiomas with central neurofibromatosis. Twenty-five of 30 cases (83%) were constitutionally heterozygous for at least one of the chromosome 22q DNA markers and sixteen of 25 informative cases (64%) displayed loss of heterozygosity (LOH). All of the 8 informative cases (100%) of meningiomas with aggressive characteristics, showed LOH on chromosome 22q whereas non-aggressive cases revealed LOH in eight of 17 informative cases (47%). At the loci on chromosome 17p, only two cases of malignant meningionas showed LOH. Our results suggest that the inactivations of putative tumor suppressor genes on chromosome 22q and 17p may correlate with aggressiveness and malignant transformation of meningiomas.

Fibroblast growth factor 2 uses PLC-gamma1 for cell proliferation and PI3-kinase for alteration of cell shape and cell proliferation in corneal endothelial cells

PURPOSE

Fibroblast growth factor 2 (FGF-2) induces endothelial-mesenchymal modulation in corneal endothelial cells, including stimulation of cell proliferation and cell shape change and induction of fibrillar collagen. In the present study, we investigated whether FGF-2 uses distinct signaling pathways for individual biological activities.

METHODS

Specific metabolic inhibitors were used to block cell proliferation, while reversion of cellular morphology (modulated with FGF-2) was determined using specific antibodies and inhibitors. Immunocytochemical analysis was performed to identify any changes observed in the cytoskeleton in relation to cell shape. Association of cytoskeleton molecules with phosphatidylinositol 3-kinase was determined using co-precipitation. Cell proliferation was assayed using a colorimetric method for determining the number of viable cells.

RESULTS

The fibroblastic morphology induced by FGF-2 reverted to a polygonal shape in cells treated with anti-FGF-2 antibody, anti-phosphatidylinositol 3-kinase antibody, LY294002, and genistein, while anti-phospholipase C gamma1 antibody did not to reverse the modulated cell morphology. Cell proliferation mediated by FGF-2 was blocked by metabolic inhibitors (genistein, LY294002 and wortmannin); genistein inhibited FGF-mediated cell proliferation in a dose-response manner and had a maximum inhibition of 80% at 100 microM, while inhibitors of phosphatidylinositol 3-kinase had less inhibitory effect than did genistein. When cytoskeleton proteins were examined, the characteristic punctated staining profiles of vinculin observed in normal cells were maintained in fibroblastic corneal endothelial cells treated with FGF-2. The inhibitors that cause reversion of cell shape also demonstrated the punctated staining potential. Likewise, the staining profiles of alpha-actinin and smooth muscle alpha-actin were not altered, regardless of cell shape. Filamentous actin and alpha-actinin were co-localized to the cytoskeleton and phosphatidylinositol 3-kinase was associated with the cytoskeleton, regardless of cell shape.

CONCLUSIONS

These findings indicate that FGF-2 uses distinct and/or dual signaling pathways for individual biological activities.

Requirement of intact human ceruloplasmin for the glutathione-linked peroxidase activity

Structural integrity may be needed for the glutathione-linked peroxidase activity of human ceruloplasmin. Intact human ceruloplasmin has a potent peroxidase property to decompose H2O2 in the presence of reduced glutathione. However, the fragment of approximately 116000 Da produced by proteolytic degradation had less than one-third of the glutathione-linked peroxidase activity of intact ceruloplasmin. When further proteolysis occurred, glutathione-linked peroxidase activity of human ceruloplasmin disappeared. In contrast, ceruloplasmin (116000 Da and <96000 Da) fragmented by proteolysis significantly removed H2O2 irrespective of the presence of reduced glutathione. Although proteolytic fragmentation of ceruloplasmin occurs, the antioxidant activity of ceruloplasmin that prevents DNA strand breaks in a metal-catalyzed reaction system was significantly maintained.

Degradation of acharan sulfate and heparin by Bacteroides stercoris HJ-15, a human intestinal bacterium

When glycosaminoglycan (GAG)-degrading enzymes were measured in normal human stool suspensions, all 5 tested different stools degraded titrable heparin and acharan sulfate. GAG-degrading bacteria were screened from the isolates of human stools. Among them, HJ-15 had the most potent activities of heparinases (GAGs-degrading enzymes). However, HJ-15 produced the enzyme even if in the media without heparin. Acharan sulfate lyase was induced by acharan sulfate and heparin. Heparinase production was also induced by these GAGs. These enzymes, acharan sulfate lyase and heparinase, were produced in exponential and stationary phase of HJ-15 growth, respectively. Optimal pHs of the acharan sulfate lyase and heparinase activities were 7.2 and 7.5, respectively. The biochemical properties of HJ-15 was similar to those of B. stercoris. However, difference from B. stercoris was utilization of raffinose. This HJ-15 also degraded chondroitin sulfates A and C.

A cell surface molecule, JL1; a specific target for diagnosis and treatment of leukemias

We previously reported a novel differentiation antigen, which is specifically expressed in stage II double positive (CD4+CD8+) human cortical thymocytes (Park et al, J Exp Med 1993; 178: 1447-1451). This study was designed to investigate the expression pattern of JL1 in various types of leukemic cells from patients and normal hematopoietic cells to evaluate the possibility as a tool for diagnosis and treatment of leukemia. The expression of JL1 antigen was observed in 75.6% of leukemic cases (117 out of 154 leukemic patients tested) on flow cytometric analysis. The percentage of JL1-positive cases of T lineage acute lymphoblastic leukemia (T-ALL) (92.6%) was higher than that of other types of leukemias (75%). The presence of JL1 antigen was also confirmed by immunoblotting and immunoprecipitation. Since the JL1 antigen is selectively expressed on the surface of human leukemic cells but not on the mature human peripheral blood cells, normal bone marrow cells and various types of normal tissues, JL1 could be an excellent candidate for an immunodiagnostic and immunotherapeutic tool for hematopoietic malignancies such as leukemia.

Resistance of Fc receptor- deficient mice to fatal glomerulonephritis

Immune complex-mediated inflammation is a common mechanism of various autoimmune diseases. Glomerulonephritis (GN) is one of these diseases, and the main mechanism of the induction of GN has been unclear. We examined the contribution of Fc receptors in the induction of nephrotoxic GN by establishing and analyzing mice deficient in the Fc receptor gamma chain (FcRgamma). Whereas all wild-type mice died from severe glomerulonephritis with hypernitremia by administration of anti-glomerular basement membrane (GBM) antibodies, all FcRgamma-deficient mice survived. Histologically, wild-type mice showed glomerular hypercellularity and thrombotic changes, whereas the renal tissue in FcRgamma-deficient mice was almost intact. Deposition of anti-GBM antibody as well as complement components in the GBM were equally observed in both wild-type and knockout mice. These results demonstrate that the triggering of this type of glomerulonephritis is completely dependent on FcR+ cells.

Genomic DNA sequence of a rice gene coding for a pullulanase-type of starch debranching enzyme

A genomic DNA containing a rice (Oryza sativa L., cv. Norin-8) gene coding for a pullulanase-type starch debranching enzyme (EC 3.2.1. 41) was sequenced (EMBL/GenBank/DDBJ accession number AB012915). Along the 15, 248 bp DNA, the pullulanase gene is split into 26 exons. The four pullulanase consensus regions are positioned in the middle portion of the sequence and are separated by long introns and 1-3 exons. Comparison of the rice cv. Norin-8 pullulanase genomic structure with that of barley pullulanase (limit dextrinase) (F. Lok et al., EMBL/GenBank/DDBJ accession number AF022725) indicates that most of the pullulanase exons are highly conserved. Alignment of the nucleotide bases of rice exon 8 with those of barley exon 8-intron 8-exon 9 fragment suggests that the 85 bp internal sequence of rice exon 8 was originally an intron, a possibility further indicated by the absence in barley and spinach (A. Renz et al., EMBL/GenBank/DDBJ accession number X83969) pullulanases of amino acid residues encoded by the 85 bp fragment.

A case of well-differentiated minute hepatocellular carcinoma with extrahepatic metastasis

A rare case of well-differentiated minute hepatocellular carcinoma (HCC) metastasizing to distant sites in a 77-year-old man with hepatitis C virus (HCV)-related cirrhosis is presented. Ultrasonography (US) disclosed a 9 mm hypoechoic lesion in segment seven (S7) of the liver, although computed tomography (CT), magnetic resonance imaging (MRI) and angiography did not reveal any space-occupying lesion. Ultrasound-guided biopsy showed the histological features of well-differentiated HCC. A plain film of the abdomen and CT revealed osteolytic changes in the sacrum and the lumbar vertebra. Ultrasound-guided biopsy of the sacrum revealed well-to-moderately differentiated HCC metastasizing from the liver. Percutaneous ethanol injection therapy (PEIT) effected complete response and completely eliminated the abnormal findings on US. Three months after PEIT, metastasis to the thoracic vertebra was revealed by CT, despite negative alpha-fetoprotein-mRNA in serum. This is the first report describing a well-differentiated HCC with metastatic potential. Further studies may provide insights into metastasis of well-differentiated HCC.

Receptor-mediated activation of murine peritoneal macrophages by antithrombin III acts as a costimulatory signal for nitric oxide synthesis

We evaluated the effect of antithrombin III (ATIII), a serine protease inhibitor (SERPIN), on induction of nitric oxide (NO) synthesis in murine peritoneal macrophages. Incubation of macrophages with ATIII plus interferon-gamma (IFN-gamma) but not ATIII alone induced nitrite accumulation (a metabolite of NO) in a dose-dependent manner. Expression of the inducible nitric oxide synthase isoform was confirmed by Western blot. NO synthesis was inhibited by NG-monomethyl-l-arginine, by complexing ATIII with thrombin or by rabbit anti-human ATIII antiserum. Addition of polymyxin B to macrophage cultures failed to inhibit ATIII/IFN-gamma-induced NO synthesis, excluding lipopolysaccharide contamination. 125I-ATIII bound to macrophages in a dose-dependent, specific, and saturable manner, with a Km of approximately 7.1 nM. Our results demonstrate that ATIII, but not ATIII/thrombin complex, acts to costimulate macrophage activation and NO synthesis via a novel receptor mediated mechanism, which may indicate a role for SERPINs in macrophage activation.

Topological defects and the optimum size of DNA condensates

Under a wide variety of conditions, the addition of condensing agents to dilute solutions of random-coil DNA gives rise to highly compact particles that are toroidal in shape. The size of these condensates is remarkably constant and is largely independent of DNA molecular weight and basepair sequence, and of the nature of condensing agent (e.g., multivalent cation, polymers, or added cosolvent). We show how this optimum size is determined by the interactions between topological defects, which unavoidably strain the circumferentially wound DNA strands in the torus.

Thiol-linked peroxidase activity of human ceruloplasmin

Human ceruloplasmin exhibited different antioxidant effects according to the electron donors in a metal-catalyzed oxidation system. Purified ceruloplasmin did not play a significant role in the protection of DNA strand breaks in the ascorbate/Fe3+/O2 system. However, when ascorbates were replaced with a thiol-reducing equivalent such as dithiothreitol, DNA strand breaks were significantly prevented by the same amount of ceruloplasmin. Ceruloplasmin did not catalyze the decomposition of H2O2 in the absence of reduced glutathione. On the contrary, ceruloplasmin showed a potent peroxidase ability to destroy H2O2 in the presence of reduced glutathione. In conclusion, the removal of H2O2 by human ceruloplasmin is not simply stoichiometric but thiol-dependent.

Synthesis and biological properties of new 1 beta-methylcarbapenems

The synthesis and biological activity of the novel series of 1 beta-methylcarbapenems, 1 and 2 were described. Most compounds displayed high potent antibacterial activity. The best compound in this series, 2a (IH201; R2 = NH2) showed an excellent and a broad spectrum as well as high renal DHP-I stability. It also possessed good in vivo efficacy and high safety.

Expression of Bfl-1 in normal and tumor tissues: Bfl-1 overexpression in cancer is attributable to its preferential expression in infiltrating inflammatory cells

Bfl-1, a member of the Bcl-2 gene family, blocks p53-mediated apoptosis and has oncogenic transforming activity. In normal tissues, the transcript of Bfl-1 is expressed abundantly in bone marrow and at a low level in several other tissues. In previous experiments, elevated expression of Bfl-1 was observed by Northern analysis of stomach cancer samples. To study the role of Bfl-1 in normal cell development and in tumorigenesis, we have analyzed the expression of Bfl-1 in normal and tumor tissues by the in situ hybridization technique. The Bfl-1 transcript was detected in the white pulp of the spleen and in the germinal center of lymphatic tissues. In tumor tissues, its expression was preferentially detected in infiltrating inflammatory cells rather than in cancer cells, suggesting that Bfl-1 is not involved in tumorigenesis.

Development of a competitive enzyme linked immuno sorbent assay to measure ceruloplasmin in gamma-irradiated rat serum

The concentrations of ceruloplasmin could not be determined by comparing the oxidase activities toward p-phenylenediamine and o-dianisidine in rat whole serum with those of purified ceruloplasmin because of the different specific amine oxidase activities of ceruloplasmin purified from normal and gamma-irradiated rats and the lability caused by freezing and thawing. A competitive enzyme linked immunosorbent assay with antigens immobilized on the solid phase was developed to measure the ceruloplasmin in rat serum. The blocking materials and pH of the coating buffer had an effect on the amount of ceruloplasmin bound to the microtiter plates. The blocking materials nonspecifically reacted with the rabbit anti-rat ceruloplasmin IgG, and consequently the coating sensitivity was decreased and standard curves were not formed completely. Because rabbit anti-rat ceruloplasmin IgG did not show any cross reactivity with rat albumin and hemoglobin, these proteins did not affect the assay at a concentration of 200 micrograms/ml. This assay is useful for measuring the concentration of ceruloplasmin in normal and irradiated rat serum.

Lymphoepithelial cysts of the pancreas: CT and sonographic findings

Two cases of rare lymphoepithelial cyst (LEC) of the pancreas are presented. Although the histogenesis of this lesion is not known, it can be histologically differentiated from other pancreatic and retropancreatic cysts. The importance of its recognition is in the distinction from cystic neoplasm of the pancreas.

Acidic polysaccharide from Panax ginseng, ginsan, induces Th1 cell and macrophage cytokines and generates LAK cells in synergy with rIL-2

We previously reported that an acidic polysaccharide from Panax ginseng named ginsan inhibits the incidence of benzo[a]pyrene-induced autochthonous lung tumors in mice. To elucidate the mechanism of antineoplastic activity, ginsan was tested for its ability to generate LAK cells and to produce cytokines. Spleen cells became cytotoxic to a wide range of tumor cells after 5 days of culture with ginsan in a non-major histocompatibility restricted manner and the activity of ginsan was 12 times higher than that of lentinan. The generation of killer cells by rIL-2 was neutralized only in the presence of anti-IL-2, whereas by ginsan it was neutralized in the presence of anti-IL-2 as well as anti-IFN gamma, or anti-IL-1 alpha. It was confirmed that ginsan induces the expression of mRNA for IL-2, IFN gamma, IL-1 alpha, and GM-CSF. Depletion of AsGM1+ cells from spleen cells reduced the generation of LAK by rIL-2. In contrast, depletion of AsGM1+ as well as Thy1+ cells, CD4+ cells, or DC8+ cells reduced the generation of LAK cells by ginsan. The serologic phenotype of rIL-2 induced LAK cells was CD8- cells, whereas the ginsan induced LAK cells, were CD8+ cells. Ginsan synergized with rIL-2 to generate LAK cells (2.0-15 fold) and the most dramatic synergy was seen at rIL-2 concentrations below 3 U/ml. Ginsan alone inhibited pulmonary metastasis of B16-F10 melanoma cells and enhanced the inhibition of lung colonies by rIL-2. These findings demonstrate that ginsan generates LAK cells from both NK and T cells through endogeneously produced multiple cytokines. This property may contribute to its effectiveness in the immunoprevention and immunotherapy of cancer.

Modulation of nitric oxide, hydrogen peroxide and cytokine production in a clonal macrophage model by the trichothecene vomitoxin (deoxynivalenol)

Characterization of how vomitoxin (VT) and other trichothecenes affect macrophage regulatory and effector function may contribute to improved understanding of mechanisms by which these mycotoxins impact the immune system. The RAW 264.7 murine cell line was used as a macrophage model to assess effects of the VT on proliferation and the production of nitric oxide (NO), hydrogen peroxide (H2O2) and cytokines. Using the MTT cleavage assay, VT at concentrations of 50 ng/ml or higher was found to significantly decrease proliferation and viability of RAW 264.7 cells without stimulation or with stimulation by lipopolysaccharide (LPS) or interferon (IFN)-gamma. In the absence of an activation agent, VT (25-250 ng/ml) had negligible effects on the production of NO, H2O2, and cytokines. Upon activation with LPS at concentrations of 10 to 100 ng/ml, VT at 25-100 ng/ml markedly enhanced production of H2O2 but was inhibitory at 250 ng/ml. VT enhancement of H2O2 production was observed as early as 12 h after LPS stimulation. When IFN-gamma was used as the stimulant, VT (25-250 ng/ml) delayed peak H2O2 production. VT (25-250 ng/ml) also markedly decreased NO production in cells activated with LPS or IFN-gamma. Interestingly, VT superinduced TNF-alpha and IL-6 production in LPS-stimulated cells and also elevated TNF-alpha in IFN-gamma stimulated cells. These results suggest that VT can selectively and concurrently upregulate or downregulate critical functions associated with activated macrophages.

Primary pulmonary sarcoma with morphologic features of biphasic synovial sarcoma: a case report

We report an unusual primary case of pulmonary sarcoma that developed in the lung of a 36-year-old woman. The tumor had histologic, immunologic and ultrastructural features identical to those of biphasic synovial sarcoma of the soft tissue. It consisted of an intimate admixture of cytokeratin and epithelial membrane antigen(EMA)-positive neoplastic epithelial cells and vimentin-positive fibroblast-like spindle cells with areas of hyalinization. The patient had a lobectomy and showed no evidence of recurrence or tumor at other sites 15 months after surgery. This case is an useful addition to the small number of published reports on pulmonary synovial sarcoma. The distinctive features of this neoplasm allow it to be different from other types of primary and metastatic malignancies in the lung.

Induction of V3-specific cytotoxic T lymphocyte responses by HIV gag particles carrying multiple immunodominant V3 epitopes of gp120

Effort to develop a vaccine to prevent infection of human immunodeficiency virus (HIV) have focused on the induction of neutralizing antibodies. In our previous study, we reported that chimeric gag-env virus-like particles (VLPs) induce neutralizing antibodies which block HIV infection. In addition to the neutralizing antibodies, the cytotoxic T-lymphocyte (CTL) response is considered to be another major immune defense mechanism required for recovery from many different viral infections. In the present study, we have constructed chimeric fusion proteins using HIV-2 gag precursor protein with (1) four neutralizing epitopes from HIV-1 gp160; (2) three tandem copies of consensus V3 domain, which have been derived from 245 different isolates of HIV-1 and carries both the principal neutralizing determinant (PND) and CTL epitopes; and (3) V3 domains from HIV-1IIIB, HIV-1MN, HIV-1RF, and HIV-1SF2. These chimeric fusion proteins were expressed in a large quantity within insect cells, and released as VLPs into the cell culture medium. The purified gag-env VLPs from all three constructs appear to be spherical particles similar to immature HIV but slightly larger than the gag VLPs. Immunoprecipitation analysis showed that the chimeric proteins were recognized not only by HIV-1 positive patient sera, but also by monoclonal and polyclonal antisera raised against V3 peptides of HIV-1IIIB, HIV-1MN, HIV-1RF, and the gp120 antiserum against HIV-1SF2. Balb/C mice immunized with these chimeric VLPs successfully induced CTL activity against V3 peptide-stimulated target cells. In addition, a high degree of cross-reactivity was observed among the four different strains of HIV-1 V3 domain, indicating that the tandem multiple consensus V3 peptide sequence carried by HIV-2 gag can be used as a potential HIV vaccine against various HIVs.

Gene cloning and characterization of thermostable lipase from Bacillus stearothermophilus L1

The gene coding for an extracellular lipase of Bacillus stearothermophilus L1 was cloned in Escherichia coli. Sequence analysis showed an open reading frame of 1254 bp, which encodes a polypeptide of 417 amino acid residues. The polypeptide was composed of a signal sequence (29 amino acids) and a mature protein of 388 amino acids. An alanine replaces the first glycine in the conserved pentapeptide (Gly-X-Ser-X-Gly) around the active site serine. The expressed lipase was purified by hydrophobic interaction and ion exchange chromatography using buffers containing 0.02% (v/v) Triton X-100. The lipase was most active at 60-65 degrees C and in alkaline conditions around pH 9-10. The lipase had highest activity toward p-nitrophenyl caprylate among the synthetic substrates and tripropionin among the triglycerides. It hydrolyzed beef tallow and palm oil more rapidly than olive oil at 50 degrees C.

Association with FcRgamma is essential for activation signal through NKR-P1 (CD161) in natural killer (NK) cells and NK1.1+ T cells

Natural killer (NK) cells exhibit cytotoxicity against variety of tumor cells and virus-infected cells without prior sensitization and represent unique lymphocytes involved in primary host defense. NKR-P1 is thought to be one of NK receptors mediating activation signals because cross-linking of NKR-P1 activates NK cells to exhibit cytotoxicity and IFN-gamma production. However, molecular mechanism of NK cell activation via NKR-P1 is not well elucidated. In this study, we analyzed the cell surface complex associated with NKR-P1 on NK cells and found that NKR-P1 associates with the FcRgamma chain which is an essential component of Fc receptors for IgG and IgE. The association between FcRgamma and NKR-P1 is independent of Fc receptor complexes. Furthermore, NK cells from FcRgamma-deficient mice did not show cytotoxicity or IFN-gamma production upon NKR-P1 cross-linking. Similarly, NK1.1+ T cells from FcRgamma-deficient mice did not produce IFN-gamma upon NKR-P1 crosslinking. These findings demonstrate that the FcRgamma chain plays an important role in activation of NK cells via the NKR-P1 molecule.

Development of a competitive enzyme linked immunosorbent assay to measure alpha 2-macroglobulin in irradiated rat serum

A competitive enzyme linked immunosorbent assay with antigen immobilized on the solid phase was developed to measure alpha 2-macroglobulin in rat serum. The cross reactivity with albumin and hemoglobin was eliminated by use of IgG fractions that were isolated after chromatography on Cibacron Blue F3-GA Sepharose immobilized rat whole serum and hemoglobin Sepharose. Blocking materials and pH of the coating buffer had no effect on the amount of alpha 2-macroglobulin that binds to the plate. When the coating amount of alpha 2-macroglobulin was 100 ng/well, at pH 7.4, 10 mM Tris-HCl containing 150 mM sodium chloride and the IgG amount added was 60 ng/well, then albumin and hemoglobin did not affect the assay at concentrations of 150 micrograms/ml or 200 micrograms/ml. This assay is useful for measuring the concentration of alpha 2-macroglobulin in normal and irradiated rat serum.

Crystal structure of nitric oxide reductase from denitrifying fungus Fusarium oxysporum

Structures of nitric oxide reductase (NOR) in the ferric resting and the ferrous CO states have been solved at 2.0 A resolution. These structures provide significant new insights into how NO is reduced in biological systems. The haem distal pocket is open to solvent, implicating this region as a possible NADH binding site. In combination with mutagenesis results, a hydrogen-bonding network from the water molecule adjacent to the iron ligand to the protein surface of the distal pocket through the hydroxyl group of Ser 286 and the carboxyl group of Asp 393 can be assigned to a pathway for proton delivery during the NO reduction reaction.

Inhibition of diabetes in non-obese diabetic mice by nicotinamide treatment for 5 weeks at the early age

To know the effects of nicotinamide (NCT) treatment for 5 weeks at the early age on insulitis and development of diabetes in non-obese diabetic (NOD) mice, this experiment was performed. Ten ICR (Institute of Cancer Research) and 15 female NOD mice at 4 weeks of age were used. Mice were assigned to ICR and NOD groups, and NOD mice were randomly divided to control and NCT-treated groups. NCT was administered to mice orally as a solution and in a dose of 500 mg/kg body weight a day from the age of 4 to 8 weeks. Diabetes onset was 18 weeks of age in control group, and 22 weeks of age in NCT-treated group. Cumulative incidences of diabetes at 25 weeks of age in control and NCT-treated NOD mice were 63 and 29%, respectively. Insulitis occurred in all NOD mice. Incidence of insulitis in total islets was decreased by NCT treatment in diabetic NOD mice, but intensity of insulitis was not improved by NCT treatment. Blood glucose level was increased markedly, and plasma insulin level was decreased by diabetes development in NOD mice. Plasma triglycerides and total cholesterol levels were increased in diabetic mice than in non-diabetic mice. In conclusion, these results suggest that NCT treatment for 5 weeks at the early age in NOD mice inhibits development of diabetes and insulitis in diabetic NOD mice.

Crystallization, preliminary diffraction and electron paramagnetic resonance studies of a single crystal of cytochrome P450nor

Cytochrome P450nor (P450nor) is a heme-containing nitric oxide reductase from the denitrifying fungus, Fusarium oxysporum. This enzyme catalyzes the reduction of NO to N2O. In the present study, we report results from preliminary crystallographic and electron paramagnetic resonance (EPR) analysis of a single crystal of P450nor. The crystal was grown in 100 mM MES buffer at pH 5.6 using PEG 4000 as a precipitant. It belongs to the orthorhombic system with cell dimensions of a = 54.99 A, b = 82.66 A, c = 87.21 A, and the space group is P2(1)2(1)2(1). The crystal diffracts synchrotron radiation at higher than 2.0 A resolution, and therefore it is suitable for X-ray crystal structure analysis at atomic resolution. Bijvoet and dispersive anomalous difference Patterson maps show a clear peak corresponding to the heme iron. The structure solution is currently underway by means of MIR and MAD techniques. EPR analysis determined the orientation of the heme within the P450nor crystal.