The transport mechanism of metallothionein is different from that of classical NLS-bearing protein

A nuclear localization signal (NLS) has been detected in several nuclear proteins. Classical NLS-mediated nuclear pore targeting is performed by using the cytosolic factors, importin alpha and importin beta, whereas nuclear translocation requires the small GTPase, Ran. In the present study, we demonstrated that nuclear localization of metallothionein (MT) differs from that of classical NLS-mediated substrates. In digitonin-permeabilized BALB/c3T3 cells, biotinylated MT was localized in the nucleus in the presence of ATP and erythrocyte cytosol in the same manner as for SV40 large T NLS-conjugated allophycocyanin (APC-NLS). Under ATP-free conditions, nuclear rim-binding was observed in both transport substrates. Rim-binding of labeled MT was competitively inhibited by the addition of an excess amount of unlabeled MT. Different elution profiles were observed for the localization-promoting activities of MT in the cytosol compared to those of APC-NLS. Furthermore, nuclear localization of MT was determined to be a wheat germ agglutinin-insensitive, GTPgammaS-sensitive, and anti-Ran antibody-sensitive process. Green fluorescent protein-metallothionein (GFP-MT) fusion protein was also localized in the nucleus in the stable transformant of CHL-IU cells. These results strongly suggest that the targeting by MT of the nuclear pore is mediated by cytosolic factor(s) other than importins and that MT requires Ran for its nuclear localization.

Remarkable axial thiolate ligand effect on the oxidation of hydrocarbons by active intermediate of iron porphyrin and cytochrome P450

In order to examine the reactivity of active intermediate derived form iron porphyrins, competitive oxidations of alkane and alkene were carried out. It has been proposed that the first step of alkane hydroxylation is H atom abstraction and that of alkene is one-electron transfer. Therefore, it is expected that alkene-alkane competitive oxidation can be used as a probe for discrimination of differences in chemical properties among active species. Cytochrome P450 and SR complex, which is a stable thiolate-ligated iron porphyrin, mediated the oxidation of alkane much more preferentially than iron porphyrin coordinated by imidazole or chloride. These results indicate that thiolate coordination alters the reactivity of the two-electron-oxidized intermediate in a manner that is much more favorable to alkane hydroxylation than the case of chloride or imidazole coordination.

A new thioether-ligated iron porphyrin as a model of a protonated form of P450 active site

Thioether-ligated iron porphyrin (complex 1) was synthesized as a model of the protonated form of P450 to explore the possible involvement of the protonated form in the catalytic cycle, and ether-ligated iron porphyrin (complex 2) was also synthesized for comparison. The thioether and ether ligands enhanced heterolytic O-O bond cleavage of peroxy acid-iron porphyrin complex even in highly hydrophobic media without the assistance of acid or base, using mCPPAA as an oxidant. Competitive oxidation of cyclooctane/cyclooctene catalyzed by iron porphyrins showed that complexes 1 and 2 are less effective than heme thiolate (P450 and a synthetic heme thiolate (SR complex)) in oxidizing alkane. The possibility that thiol-ligated heme, which is a protonated form of heme thiolate, is not involved in the active intermediate structure of P450 is indicated by this result. This is the first report concerning the oxidizing ability of a thioether-ligated iron porphyrin.

Considerable time from the onset of plaque rupture and/or thrombi until the onset of acute myocardial infarction in humans: coronary angiographic findings within 1 week before the onset of infarction

BACKGROUND

It has been thought that the thrombi and bleeding in plaques that occur after plaque rupture or endothelial damage from vessels with mild stenosis suddenly occlude the lumen and cause acute myocardial infarction (AMI). However, our hypothesis is that thrombi and bleeding may not suddenly occlude the lumen.

METHODS AND RESULTS

The study group consisted of 20 patients who had coronary angiograms performed within 1 week (3+/-3 days) before AMI and 20 control patients who had coronary angiograms performed 6 to 18 months (282+/-49 days) before AMI. The features of infarct-related coronary segments (IRCS) at 3 days before AMI were the presence of a significant stenosis of >50% (95% in incidence and 71+/-12% diameter stenosis) and Ambrose's type II eccentric lesions (plus multiple irregularities), an indicator of plaque rupture and/or thrombi (60% [70%]), and the features at 1 year before AMI were mild stenosis of <50% (95% incidence and 30+/-18% diameter stenosis) with rare Ambrose's type II eccentric lesions (plus multiple irregularities) (10% [10%]). The same relation was observed in each of the 4 subgroups with Q-wave infarction, non-Q-wave infarction, preceding effort angina within 1 month before AMI, and no preceding effort angina.

CONCLUSIONS

The appearance of marked progression and Ambrose's type II eccentric lesion on coronary angiograms 3 days before AMI suggests the presence of a considerable time from the onset of plaque rupture and/or thrombi until the onset of AMI. These features may be predictors of AMI. The concept provides new insight into the mechanism and prevention of human AMIs.

Homeobox gene Hex is essential for onset of mouse embryonic liver development and differentiation of the monocyte lineage

Disruption of the mouse Hex gene resulted in embryonic lethality around embryonic age (E) 10.5, due to no substantial liver formation. Expression of albumin was detectable in heterozygous (Hex(+/-)) but not in homozygous (Hex(-/-)) [corrected] embryos at E8.5. Instead of liver bud formation at E9.5, a liver-like capsule structure was observed in Hex(-/-) [corrected] embryos. In Hex(-/-) [corrected] mutant liver, we found no hepatocytes but no signs of apoptotic cell death in the area. Expression of transcription factors involved in hepatocyte differentiation, hepatocyte nuclear factor (Hnf)3beta, Hnf6, Hnf4alpha and Hnf1alpha, were restricted to the capsule and internal matrix-like structure in the mutant liver and expression of a subset of these factors were reduced. Hematopoiesis of monocytes was impaired in mutant embryos while erythroid lineage was unaffected. These results indicate that Hex plays an essential role in progenitor cells which commit to the hepatic endoderm and in the hematopoietic differentiation of the monocyte lineage.

Superoxide dismutase activity of iron(II)TPEN complex and its derivatives

Superoxide is involved in the pathogenesis of various diseases, such as inflammation, ischemia-reperfusion injury and carcinogenesis. Superoxide dismutases (SODs) catalyze the disproportionation reaction of superoxide to produce oxygen and hydrogen peroxide, and can protect living cells against the toxicity of free radicals derived from oxygen. Thus, SODs and their functional mimics have potential value as pharmaceuticals. We have previously reported that Fe(II)tetrakis-N,N,N',N'-(2-pyridylmethyl)ethylenediamine (Fe(II)TPEN) has an excellent SOD activity (IC50 = 0.5 microM) among many iron complexes examined (J. Biol. Chem., 264, 9243-9249 (1989)). Fe(II)TPEN can act like native SOD in living cells, and protect Escherichia coli cells from free radical toxicity caused by paraquat. In order to develop more effective SOD functional mimics, we synthesized Fe(II)TPEN derivatives with electron-donating or electron-withdrawing groups at the 4-position of all pyridines of TPEN, and measured the SOD activities and the redox potentials of these complexes. Fe(II) tetrakis-N,N,N',N'-(4-methoxy-2-pyridylmethyl)ethylenediamine (Fe(II)(4MeO)4TPEN) had the highest SOD activity (IC50 = 0.1 microM) among these iron-based SOD mimics. In addition, a good correlation was found between the redox potential and the SOD activity of 15 Fe(II) complexes, including iron-based SOD mimics reported in the previous paper (J. Organometal. Chem., in press). Iron-based SOD mimics may be clinically applicable, because these complexes are generally tissue-permeable and show low toxicity. Therefore our findings should be significant for the development of clinically useful SOD mimics.

ICTS, an interventional cardiology training system

In this article, we present an Interventional Cardiology Training System developed by the Medical Application Group at Mitsubishi Electric in collaboration with the Center for Innovative Minimally Invasive Therapy. The core of the ICTS is a computer simulation of interventional cardiology catheterization. This simulation integrates clinical expertise, research in learning, and technical innovations to create a realistic simulated environment. The goal of this training system is to augment the training of new cardiology fellows as well as to introduce cardiologists to new devices and procedures. To achieve this goal, both the technical components and the educational content of the ICTS bring new and unique features: a simulated fluoroscope, a physics model of a catheter, a haptic interface, a fluid flow simulation combined with a hemodynamic model and a learning system integrated in a user interface. The simulator is currently able to generate--in real-time--high quality x-ray images from a 3D anatomical model of the thorax, including a beating heart and animated lungs. The heart and lung motion is controlled by the hemodynamic model, which also computes blood pressure and EKG. The blood flow is then calculated according to the blood pressure and blood vessel characteristics. Any vascular tool, such as a catheter, guide wire or angioplasty balloon can be represented and accurately deformed by the flexible tool physics model. The haptics device controls the tool and provides appropriate feedback when contact with a vessel wall is detected. When the catheter is in place, a contrast agent can be injected into the coronary arteries; blood and contrast mixing is computed and a visual representation of the angiogram is displayed by the x-ray renderer. By bringing key advances in the area of medical simulation--with the real-time x-ray renderer for instance--and by integrating in a single system both high quality simulation and learning tools, the ICTS opens new perspectives for computer based training systems.

High expression of the second lysine decarboxylase gene, ldc, in Escherichia coli WC196 due to the recognition of the stop codon (TAG), at a position which corresponds to the 33th amino acid residue of sigma38, as a serine residue by the amber suppressor, supD

Escherichia coli WC196, which was obtained from the strain W3110 by nitrosoguanidine mutagenesis as an overproducer of lysine, produced approximately twenty times more cadaverine than did W3110, and had a twenty fold higher level of rpoS gene product, sigma38, than in W3110. Both WC196 and W3110 had a stop codon (TAG) in rpoS at position which corresponds to the 33th residue of sigma38 protein. In addition, WC196 but not W3110 had a mutation in the gene encoding Ser-tRNA (SerU), called, supD. Analysis of the amino acid sequence of a sigma38 preparation from WC196 showed that the 33th residue of sigma38 is a serine residue. The deltarpoS deltacadA mutant of E. coli W3110 harboring the plasmid containing rpoS, in which the TAG codon was converted to a TCG codon for serine-33 residue of sigma38, expressed a significant amount of Ldc and accumulated a large amount of sigma38. However, the deltarpoS deltacadA mutant of W3110 with the plasmid containing the intact rpoS from W3110 could synthesize neither sigma38 nor Ldc significantly.

Expression of perforin and Fas ligand mRNA in the liver of viral hepatitis

Cytotoxic T lymphocytes (CTLs) play an important role in the pathogenesis of viral hepatitis. We studied the expression of mRNAs of perforin and Fas ligand (Fas-L) in biopsy specimens from chronic hepatitis B (CHB) (15 cases) and hepatitis C (CHC) patients (13 cases). Both perforin and Fas-L mRNAs were detected in all cases of both CHB and CHC. No messages were detected in the control livers from two cases of fatty liver, a case of Gilbert's syndrome, and a case of Dubin-Johnson syndrome. Semiquantitative analysis revealed a positive correlation between the intensity of perforin and Fas-L mRNAs in both CHB and CHC. In CHB, the intensity of both perforin and Fas-L mRNAs showed a positive correlation with the histological activity and serum alanine aminotransferase level, while the correlation was not apparent in CHC. These results suggest that both perforin and Fas/Fas-L systems are involved in the pathogenesis of liver cell injury of CHB and CHC.

Precursor genes of future pandemic influenza viruses are perpetuated in ducks nesting in Siberia

Influenza A viruses of different subtypes were isolated from fecal samples of ducks in their nesting areas in Siberia in summer from 1996 to 1998. Phylogenetic analysis of the NP genes of the isolates in Siberia and those in Hokkaido, Japan on their flyway of migration from Siberia to the south in autumn revealed that they belong to the Eurasian lineage of avian influenza viruses. It is noted that the genes of the isolates in Siberia are closely related to those of H5N1 influenza virus strains isolated from chickens and humans in Hong Kong in 1997 as well as to those of isolates from domestic birds in southern China. The results indicate that influenza viruses perpetuated in ducks nesting in Siberia should have contributed genes in the emergence of the H5N1 virus in Hong Kong. Vaccine prepared from avirulent A/duck/Hokkaido/4/96 (H5N3) influenza virus was potent enough to protect mice from challenge with lethal dose of the pathogenic H5N1 virus [19]. Intensive surveillance study of aquatic birds especially in Siberia is, therefore, stressed to provide information on the future pandemic influenza virus strains and for vaccine preparation.

Molecular characterization of a novel gamma-glutamyl transpeptidase homologue found in rat brain

A cDNA clone for a novel homologue to gamma-glutamyl transpeptidase (gamma-GTP), termed GTPH, was isolated from a rat brain expression cDNA library using antisera against total brain synaptosomal fractions. The cloned GTPH consists of 641 amino acid residues (78 kDa) and exhibits structural similarity with a conventional type of gamma-GTP that is predominantly expressed in the liver: They share significant amino acid homology (33% identity, 73% similarity) spanning over the entire sequence. RNA analyses revealed that GTPH mRNA expression is found only in the nervous system, including all brain regions, eyes and peripheral ganglia, and increases during development. Endogenous GTPH protein is a membrane-bound glycoenzyme and migrates as 90-100 kDa in polyacrylamide gels. Taken together, GTPH is a novel form of a gamma-GTP-like molecule expressed exclusively in the nervous system.

Adrenomedullin and nitric oxide inhibit human endothelial cell apoptosis via a cyclic GMP-independent mechanism

Adrenomedullin, which was discovered as a vasodilating peptide, has been reported to be produced in various organs, in which adrenomedullin regulates not only vascular tone but also cell proliferation and differentiation in an autocrine/paracrine manner. We evaluated the effect of adrenomedullin on endothelial cell apoptosis. Human umbilical vein endothelial cells underwent apoptosis when cultured in serum-free medium. Treatment with adrenomedullin reduced the number of cells with pyknotic nuclei (Hoechst 33258 staining) and inhibited cell death (dimethylthiazol-diphenyltetrazolium bromide assay) in a dose-dependent manner. The administration of adrenomedullin did not alter the expression levels of Bcl-2 family proteins. Experiments with analogs of cAMP or a cAMP-elevating agonist demonstrated that elevation of the intracellular cAMP concentration does not mediate the antiapoptotic effect of adrenomedullin. The coadministration of N-nitro-L-arginine methyl ester (2 mmol/L), an inhibitor of nitric oxide synthase, abrogated the effect of adrenomedullin. Lower doses of sodium nitroprusside (1 to 10 micromol/L), a nitric oxide donor, mimicked the antiapoptotic effect of adrenomedullin. The antiapoptotic effect of sodium nitroprusside was not attenuated by the inhibition of soluble guanylyl cyclase with 1 micromol/L oxadiazolo-quinoxalin-1-one nor could apoptosis be inhibited by the incubation of human umbilical vein endothelial cells with 1 mmol/L 8-bromo-cGMP, a cell-permeant cGMP analog. These results indicate that adrenomedullin and nitric oxide inhibit endothelial cell apoptosis via a cGMP-independent mechanism.

A2-Pancortins (Pancortin-3 and -4) are the dominant pancortins during neocortical development

We have identified a novel mouse gene named pancortin that is expressed dominantly in the mature cerebral cortex. This gene produces four different species of proteins, Pancortin-1-4, sharing a common region in the middle of their structure with two variations at the N-terminal (A1 or A2 part) and C-terminal (C1 or C2 part) sides, respectively. In the present study, we showed that expression of mRNAs for A2-Pancortins (Pancortin species that contain the A2 part, i.e., Pancortin-3 and -4) is more dominant than that of mRNAs for A1-Pancortins (Pancortin species that contain the A1 part, i.e., Pancortin-1 and -2) in the prenatal mouse cerebral neocortex. Using western blot analysis, we found that substantial amounts of both A2-Pancortins were present in the prenatal cerebral neocortex and P19 cells after inducing neuronal differentiation. A2-Pancortins were still present in the cerebral neocortex of the adult, although their mRNAs were hardly detected. In contrast, the amount of A1-Pancortins did not increase after the third postnatal week in spite of their intense gene expression. Furthermore, we showed that recombinant Pancortin-3, one of the A2-Pancortins, was a secreted protein, in contrast to Pancortin-1 (one of the A1-Pancortins). These results suggest that A2-Pancortins are extracellular proteins essential for neuronal differentiation and that their molecular behavior is distinct from that of A1-Pancortins.

[Malignant pheochromocytoma with remarkable response to CVD chemotherapy--a case report]

A 60-year-old man was admitted to our hospital with the chief complaint of a left upper abdominal mass. 131I-MIBG scintiscan revealed a left upper abdominal mass, and the patient's serum catecholamine level was very high. Our diagnosis was pheochromocytoma of the left adrenal gland. On Oct. 19, 1995, a left nephrectomy and adrenectomy were performed. The serum catecholamine level then decreased and blood pressure was normalized. Two years later, it became difficult to control the patient's hypertension, and multiple metastatic liver cancer was found by an abdominal CT scan. The diagnosis of malignant pheochromocytoma was confirmed by the accumulation of 131I-MIBG in the liver. We started CVD chemotherapy. After 10 cycles of this chemotherapy, the serum catecholamine level was almost normalized and the metastatic liver cancer was reduced to one-third in size.

Dorsal induction from dorsal vegetal cells in Xenopus occurs after mid-blastula transition

We performed some experiments to investigate the temporal and spatial details of the dorsal induction exerted by dorsal vegetal cells in Xenopus embryo. Two dorsal vegetal cells (D1 cells) were transplanted into the ventral vegetal region of a recipient at the 32-cell stage. At various times after transplantation, the ventral animal-equatorial part was explanted and cultured. The explants isolated 5.5 h after transplantation (time 5.5) elongated and formed somites. In RT-PCR analysis, the expression of dorsal gene, chordin was activated in the explants isolated after time 4.0 (about the 4000-cell stage which corresponds to the mid blastula transition (MBT)) at control stage 10. In another series of experiments, ventral animal-equatorial and dorsal vegetal parts were isolated from the 4000-cell stage embryos and they were combined for 2.0-2.5 h. These ventral animal-equatorial explants elongated and formed somites. The chordin expression was also observed in the explants. But the 32- and 256-cell stage dorsal vegetal cells failed to exert the dorsalizing activity within the 2.0-2.5 h of the conjugation. These results suggest that 2 h contact after MBT is necessary and sufficient for the dorsal induction from the dorsal vegetal cells and it occurs as a result of the zygotic gene expression. Consistent with this idea, the zygotic dorsal genes, siamois and chordin were expressed on the upper regions of the transplanted D1 descendants at stage 10. Furthermore, this region began to gastrulate when the D1 cell was transplanted with upside-down orientation. Our data indicate that the upper region of the D1 descendants by itself act as the Spemann organizer rather than the Nieuwkoop center.

Effects of Dai-kenchu-to on levels of 5-hydroxytryptamine (serotonin) and vasoactive intestinal peptides in human plasma

We examined the effects of Dai-kenchu-to (DKCT) on the levels of vasoactive intestinal peptide (VIP) and 5-hydroxytryptamine (serotonin; 5-HT) in plasma taken from 6 healthy subjects. A single oral administration of 7.5 g DKCT caused significant increases in plasma VIP at 30, 60 to 90 and 120 min (3.5-5.5 pg/ml), compared with the response in a placebo group (about 1.0 pg/ml). DKCT also caused significant increases in plasma 5-HT at 30 (121.8+/-7.3 ng/ml) and 60 (156.5+/-8.0 ng/ml) min, compared with the response in the placebo group (about 101 ng/ml). These results indicate that the stimulatory effect of DKCT on VIP-immunoreactive substance (VIP-IS) secretion is due, at least in part, to increased 5-HT levels in the abdomen. As a consequence, increased VIP-IS may improve feelings of coldness in the abdomen.

[Giant osteoma of the temporal bone with otitis media: a case study]

A 71-year-old female presented with a giant osteoma of the right temporal bone and otitis media. Computed tomography (CT) and magnetic resonance imaging (MRI) confirmed the presence of the giant osteoma. An operation was performed to alleviate the difficult-to-treat otitis media and to address the related cosmetic problem. During the operation, three-dimensional CT (3D-CT) was very helpful in understanding the relationship between the tumor and the peripheral structures. Removal of the tumor improved the patient's otitis media. Osteoma of the temporal bone is rare. Only twenty-one cases of mastoid osteoma have been reported in Japan. In the present study, we review osteomas of the temporal bone and discuss their management.

Lactoferrin protects against UV-B irradiation-induced corneal epithelial damage in rats

PURPOSE

Lactoferrin supplementation suppresses ultraviolet light B (UV-B)-induced oxidation of cultures of human corneal epithelial cells. To investigate the protective effect of lactoferrin containing eyedrops against UV-B-induced corneal damage in vivo, we examined lactoferrin efficacy in a rat UV-B keratitis model.

METHODS

Sprague-Dawley rats were irradiated with >10 kJ/m2 after anesthetization, and then corneal epithelial defect was observed at 24 h postirradiation. The pre- or postapplication of vehicle or lactoferrin-containing eyedrops was performed, and then corneal epithelial damage was scored based on fluorescein staining.

RESULTS

Posttreatment with lactoferrin did not inhibit the extent of corneal damage and did not affect wound healing. However, pretreatment by topical application of lactoferrin suppressed development of a corneal epithelial defect induced by UV-B irradiation in rats.

CONCLUSION

These results suggest that the presence of lactoferrin in human tear fluid may inhibit UV-induced corneal epithelial damage.

Mechanism of superoxide dismutase-like activity of Fe(II) and Fe(III) complexes of tetrakis-N,N,N',N'(2-pyridylmethyl)ethylenediamine

The superoxide dismutase (SOD) activity of iron(II) tetrakis-N,N,N',N'(2-pyridylmethyl)ethylenediamine complex (Fe-TPEN) was reexamined using a pulse radiolysis method. In our previous study (J. Biol. Chem., 264, 9243-9249 (1989)), we reported that this complex has a potent SOD activity in a cyt. c (cytochrome c)-based system (IC50 = 0.8 microM) and protects E. coli cells against paraquat toxicity. The present pulse radiolysis experiment revealed that Fe(II)TPEN reacts stoichiometrically with superoxide to form Fe(III)TPEN with a second-order rate constant of 3.9 x 10(6) M-1 S-1 at pH 7.1, but superoxide did not reduce Fe(III)TPEN to Fe(II)TPEN. The reaction of Fe(III)TPEN and superoxide was biphasic. In the fast reaction, an adduct (Fe(III)TPEN-superoxide complex) was formed at the second-order rate constant of 8.5 x 10(5) M-1 S-1 at pH 7.4. In the slow one, the adduct reacted with another molecule of the adduct, regenerating Fe(III)TPEN. In the cyt. c method with catalase, this Fe(III)TPEN-superoxide complex showed cyt. c oxidation activity, which had led to overestimation of its SOD activity. Based on the titration data, the main species of complex in aqueous media at neutral pH was indicated to be Fe(III)TPEN(OH-). A spectral change after the reduction with hydrated electron indicates that the OH- ion coordinates directly to Fe(III) by displacing one of the pyridine rings. The X-ray analysis of [Fe(II)TPEN]SO4 supported this structure. From the above results we propose a novel reaction mechanism of FeTPEN and superoxide which resembles a proton catalyzed dismuting process, involving Fe(III)TPEN-superoxide complex.

Cytokine profile in the liver of primary biliary cirrhosis

We characterized the cytokine profile in the liver of patients with primary biliary cirrhosis (PBC). Total RNA was extracted from the biopsy specimens of 9 patients with early-stage PBC, 10 with chronic hepatitis C (CHC), and 4 normal controls. cDNA was prepared and amplified with a polymerase chain reaction using primers for interferon (IFN)-gamma and interleukin (IL)-2, -4, -5, -6, -10, -12 (p40), and -15. Cytokines such as IFN-gamma and IL-5, -6, -10, -12, and -15 were expressed in most cases of PBC. Expression rates of IL-5 and IL-6 were higher than in CHC and controls. The higher expression rate of IL-5 in PBC was associated with eosinophil infiltration. IL-2 and IL-4 were rarely detected. Semiquantitative analysis revealed that the expression of IFN-gamma and IL-10 was reversed in PBC and CHC: high IFN-gamma and low IL-10 in PBC and high IL-10 and low IFN-gamma in CHC. These results suggest that cytokine expression is skewed in PBC and both Th1 and Th2 cytokines may play a role in the pathogenesis.

Infection of the erythroid cell line, KU812Ep6 with human parvovirus B19 and its application to titration of B19 infectivity

A human parvovirus B19 (B19) infectivity assay was developed using the erythroid cell line, KU812Ep6. KU812Ep6 was cloned for high efficiency infection with B19 in vitro, in the presence of erythropoietin by a limiting dilution method from the parent cell line, KU812. B19 was effectively propagated in KU812Ep6 and was detected for B19 antigens, VP1 and VP2. The titers of B19 positive sera measured with KU812Ep6 cells were in the range of 10(6) to 10(8) TCID50 ml. This KU812Ep6 infectivity assay had a 10(3)-10(4.5) higher sensitivity than the colony forming unit-erythroid (CFU-e) injury assay. It was calculated that one TCID50 needed 10(3) B19 genome copies, judging from the infectivity assay and semi-quantitative PCR. The KU812Ep6 infectivity assay was also used to determine infectivity of B19 in vitro, and to evaluate inactivation, as well as clearance of the virus. The inactivation of B19 by heating was carried out and infectivity declined from 10(4) TCID50 ml to < 10 TCID50 ml (lower limit of detection) at 60 degrees C for 3 h or at 70 degrees C for 30 min, but only decreased to 10(2.5) TCID50 ml at 50 degrees C for 8 h.

Low frequency of genetic change in p53 immunopositive clones in human epidermis

Sun-exposed skin of Caucasians harbors thousands of p53-mutated clones, which are clinically invisible. Using whole mount immunostaining for p53 or Ki67 antigens, p53 sequencing, and loss of heterozygosity analysis, we have further characterised these clones. Loss of heterozygosity for the alleles examined is uncommon with the exception of 9q, which occurred in 28.3% of the samples. P53 clones are more common and larger in individuals with basal cell carcinoma than in control subjects (p < 0.03). Loss of heterozygosity is also more common in clones from individuals with basal cell carcinoma than in clones from subjects without a history of basal cell carcinoma, as would be expected if both relate to ultraviolet radiation exposure. p53 sequencing of clones is in keeping with the mutagenic role of ultraviolet radiation. Surprisingly, skin found to harbor p53 clones showed no clusters of Ki67 positive cells, unlike the situation for actinic keratoses or basal cell carcinomas. These results show that in human skin p53 mutation is not directly associated with genomic instability or abnormal cell cycling; that the p53 immunopositive clones are either genetically distinct or precursors to other squamous cell lesions of skin; and that p53 immunopositive clones are early lesions, in that gross disturbance of proliferation has not already occurred.

Incidence of skin cancers and precancerous lesions in Japanese--risk factors and prevention

An examination of the occurrence of skin cancers and precancerous lesions among residents of Kasai City (34 degrees 56' N) since 1992, and of le-island (25 degrees 10' N) since 1993, has been conducted to characterize the prevalence and incidence of skin cancers in Japanese people and to evaluate risk and preventive factors. The mean prevalence of actinic keratosis (AK) in residents of Kasai City and le-island was 203.33 and 756.26, respectively, indicating that twice the dose of UVB radiation causes a 3-4 fold higher incidence of AK, although life styles, including types of occupations, differ in these two locations. Working outdoors, having skin type I and/or a history of severe sunburns during childhood were found to be important risk factors, while the use of cosmetics after 20 years of age was a protective factor, for AK and possibly for skin cancers. Further, sunscreen use among males over 60 years of age in Kasai City from 1994 through 1998 suggested that sunscreen use may reduce AK development in older people. Four and 12 cases of skin cancers were found in residents of Kasai City (from 1992 to 1997) and on le-island (from 1993 to 1998), respectively. These numbers are too small to establish the prevalence of skin cancer in Japanese, but indicate that people living in areas of higher ambient solar radiation have a higher incidence of skin cancer. This epidemiological study strongly indicates that sun protection is the major modality to reduce sun-induced cutaneous tumors in Japanese.

Effect of galardin on collagen degradation by Pseudomonas aeruginosa

The authors examined the effect of a synthetic peptidyl hydroxamate inhibitor of matrix metalloproteinase, Galardin, on collagen degradation by Pseudomonas aeruginosa (P. aeruginosa) in the presence or absence of keratocytes. Type I collagen gels, with or without suspended keratocytes, were incubated under medium containing sterile P. aeruginosa culture broth and/or Galardin for 24 hr. Degradation of collagen fibrils during culture was measured by the release of hydroxyproline. The conditioned media were also subjected to gelatin zymography and Western blotting to analyse the activation, by P. aeruginosa factor(s), of matrix metalloproteinases (MMPs) released by keratocytes. The effects of protease inhibitors, aprotinin, leupeptin and pepstatin, on collagen degradation by P. aeruginosa were also examined. P. aeruginosa broth by itself induced collegen gel degradation. When keratocytes were present, P. aeruginosa broth increased the amount of degraded collagen even further. Galardin significantly reduced the amounts of collagen degraded by P. aeruginosa culture broth, whether keratocytes were present or absent in the gel. However, the protease inhibitors had no inhibitory effects on collagen degradation. Gelatin zymography and Western blotting revealed that inactive proMMP-1, -2 and -3, released by keratocytes, were converted to active forms in the presence of P. aeruginosa broth. Galardin decreased the amounts of active MMPs and increased those of inactive proMMPs, suggesting that Galardin inhibited the activation of proMMPs by P. aeruginosa. The present results suggest that Galardin inhibits the keratocyte-mediated collagen degradation by P. aeruginosa culture broth, resulting from preventing the conversion of proMMPs to active MMPs.

Potential role of hepatocyte growth factor, a novel angiogenic growth factor, in peripheral arterial disease: downregulation of HGF in response to hypoxia in vascular cells

BACKGROUND

Although hepatocyte growth factor (HGF), a novel angiogenic growth factor, plays an important role in angiogenesis, regulation of local HGF production under hypoxia has not yet been clarified in vascular smooth muscle cells (VSMC) and endothelial cells (EC). Thus, we have studied the role of HGF in hypoxia-induced endothelial injury and the regulation of local vascular HGF expression in response to hypoxia.

METHODS AND RESULTS

HGF attenuated hypoxia-induced endothelial cell death. Importantly, hypoxic treatment of EC resulted in a significant decrease in local HGF production according to the severity of hypoxia and increased VEGF. Similarly, hypoxia significantly decreased in mRNA and protein of HGF and increased VEGF production in VSMC. In organ culture system, local HGF production was also significantly decreased by hypoxia (P<0.01). Downregulation of HGF by hypoxia is due to a significant decrease in cAMP, as hypoxic treatment decreased cAMP, a stimulator of HGF. Although active TGF-beta, a suppressor of HGF, was increased at 72 hours after hypoxic treatment, treatment of anti-TGF-beta antibody did not attenuate decreased HGF production. Finally, rHGF was intra-arterially administered into unilateral hind limb ischemia rabbits, to evaluate in vivo angiogenic activity. Of importance, a single intra-arterial administration of rHGF reduced severe necrosis due to ischemia in rabbit muscle, accompanied by a significant increase in angiographic score (P<0.01).

CONCLUSIONS

Overall, these data demonstrated that hypoxic treatment of vascular cells significantly downregulated HGF production due to decreased cAMP, suggesting their potential roles in the pathophysiology of ischemic diseases. Moreover, administration of rHGF induced therapeutic angiogenesis, accompanied by improvement of necrotic changes in the ischemic hind limb model, as cytokine supplement therapy for peripheral arterial disease.

Potential role of hepatocyte growth factor, a novel angiogenic growth factor, in peripheral arterial disease: downregulation of HGF in response to hypoxia in vascular cells

BACKGROUND

Although hepatocyte growth factor (HGF), a novel angiogenic growth factor, plays an important role in angiogenesis, regulation of local HGF production under hypoxia has not yet been clarified in vascular smooth muscle cells (VSMC) and endothelial cells (EC). Thus, we have studied the role of HGF in hypoxia-induced endothelial injury and the regulation of local vascular HGF expression in response to hypoxia.

METHODS AND RESULTS

HGF attenuated hypoxia-induced endothelial cell death. Importantly, hypoxic treatment of EC resulted in a significant decrease in local HGF production according to the severity of hypoxia and increased VEGF. Similarly, hypoxia significantly decreased in mRNA and protein of HGF and increased VEGF production in VSMC. In organ culture system, local HGF production was also significantly decreased by hypoxia (P<0.01). Downregulation of HGF by hypoxia is due to a significant decrease in cAMP, as hypoxic treatment decreased cAMP, a stimulator of HGF. Although active TGF-beta, a suppressor of HGF, was increased at 72 hours after hypoxic treatment, treatment of anti-TGF-beta antibody did not attenuate decreased HGF production. Finally, rHGF was intra-arterially administered into unilateral hind limb ischemia rabbits, to evaluate in vivo angiogenic activity. Of importance, a single intra-arterial administration of rHGF reduced severe necrosis due to ischemia in rabbit muscle, accompanied by a significant increase in angiographic score (P<0.01).

CONCLUSIONS

Overall, these data demonstrated that hypoxic treatment of vascular cells significantly downregulated HGF production due to decreased cAMP, suggesting their potential roles in the pathophysiology of ischemic diseases. Moreover, administration of rHGF induced therapeutic angiogenesis, accompanied by improvement of necrotic changes in the ischemic hind limb model, as cytokine supplement therapy for peripheral arterial disease.

Fluorescent Indicators for Imaging Nitric Oxide Production

The membrane-permeating indicator DAF-FM DA is transformed by intracellular esterases into the highly water-soluble dye DAF-FM, which traps NO produced by NO synthase (NOS) to yield a highly fluorescent triazole compound in cells (see schematic diagram). Monitoring with a fluorescence microscope should allow direct identification of intracellular production and location of NO.

Cytokine profile in the liver of primary biliary cirrhosis

We characterized the cytokine profile in the liver of patients with primary biliary cirrhosis (PBC). Total RNA was extracted from the biopsy specimens of 9 patients with early-stage PBC, 10 with chronic hepatitis C (CHC), and 4 normal controls. cDNA was prepared and amplified with a polymerase chain reaction using primers for interferon (IFN)-gamma and interleukin (IL)-2, -4, -5, -6, -10, -12 (p40), and -15. Cytokines such as IFN-gamma and IL-5, -6, -10, -12, and -15 were expressed in most cases of PBC. Expression rates of IL-5 and IL-6 were higher than in CHC and controls. The higher expression rate of IL-5 in PBC was associated with eosinophil infiltration. IL-2 and IL-4 were rarely detected. Semiquantitative analysis revealed that the expression of IFN-gamma and IL-10 was reversed in PBC and CHC: high IFN-gamma and low IL-10 in PBC and high IL-10 and low IFN-gamma in CHC. These results suggest that cytokine expression is skewed in PBC and both Th1 and Th2 cytokines may play a role in the pathogenesis.

Practical methods for detection of nitric oxide

Nitric oxide (NO), which is generated in vivo through conversion of L-arginine to L-citrulline by NO synthase (NOS), mediates many physiological and pathophysiological processes. At least two distinct isoforms of NOS have been identified, constitutive NOS (cNOS) and inducible NOS (iNOS). The cNOS, which is constitutively expressed in endothelial cells and central and peripheral neuronal cells, requires both calcium and calmodulin for its activation. Cells expressing cNOS generally produce small amounts of NO, because of their low levels of cNOS protein. On the other hand, iNOS, which is induced in cells stimulated with endotoxins, produced larger amounts of NO. Because of the short half-life, it is difficult to detect NO in situ directly, especially from cells expressing cNOS. In this review, we discuss practical methods for NO detection, which are useful for the detection of small amounts of NO from cNOS and for the bioimaging of living cells and cultured tissues.

[Case of stage IVb gastric cancer in which favorable anti-tumor effect and good QOL were observed due to UFTP therapy after low-dose CDDP-tegafur therapy]

A patient with stage IVb advanced gastric cancer, who was Group 4 lymph node metastasis positive, underwent two postoperative courses of low-dose CDDP-tegafur therapy (800 mg/body/day of tegafur + 5 mg/body/5 administrations, 2 days of rest, of cisplatin). UFTP therapy (400 mg/body/day of UFT + 5 mg/body/twice weekly of cisplatin) was thereafter given on an outpatient basis. The patient has now been receiving this therapy for one year and six months. The anti-tumor effect has been maintained and the tumor has been reduced in size by 89% without any adverse reactions. A good QOL has been observed. The present therapy can be performed safely at home and appears to be a favorable treatment from the viewpoint of QOL.

Positive and negative regulation of the human heme oxygenase-1 gene expression in cultured cells

To elucidate the regulation of the human heme oxygenase-1 (hHO-1) gene expression, we assessed approximately 4 kb of the 5'-flanking region of the hHO-1 gene for basal promoter activity and sequenced approximately 2 kb of the 5'-flanking region. A series of deletion mutants of the 5'-flanking region linked to the luciferase gene was constructed. Basal level expression of these constructs was tested in HepG2 human hepatoma cells and HeLa cervical cancer cells. By measuring luciferase activity, which was transiently expressed in the transfected cells, we found a positive regulatory region at position -1976 to -1655 bp. This region functions in HepG2 cells but not in HeLa cells. A negative regulatory region was also found at position -981 to -412 bp that functions in both HepG2 cells and HeLa cells.

Inhibition of E. coli growth by fullerene derivatives and inhibition mechanism

Cationic ammonium fullerene derivatives (C60-bis(N, N-dimethylpyrrolidinium iodide) and C60-bis(N-methylpiperazinium iodide)) suppressed E. coli growth, whereas an anionic derivative (C60-dimalonic acid) did not. Both cationic derivatives inhibited E. coli dioxygen consumption. Inhibition of energy metabolism is concluded to be a mechanism of the growth inhibition effect of fullerene derivatives.

Novel Fluorescent Probes for Singlet Oxygen

The first fluorescent chemical traps for (1)O(2) have been developed. DPAXs react specifically with (1)O(2) to yield the corresponding endoperoxides, DPAX-EPs (see scheme; X = H, Cl, F). DPAXs scarcely fluoresce, while DPAX-EPs are strongly fluorescent. Since the fluorescence of these probes is unaffected by H(2)O(2), superoxide, and nitric oxide, they are useful for the selective detection of (1)O(2) in biological systems.

Effect of Dai-kenchu-to on levels of 3 brain-gut peptides (motilin, gastrin and somatostatin) in human plasma

We examined the effect of Dai-kenchu-to (DKCT), a traditional Chinese (Kampo) medicine, on the levels of 3 brain-gut peptides (motilin, gastrin and somatostatin) in plasma from 24 healthy subjects. A single oral administration of DKCT, at a dose of 7.5 g, caused significant increases in plasma motilin levels (about 12 pg/ml) at 60 to 90 min, compared with a placebo-treated group. Transient elevations of gastrin levels were noted after administration of both DKCT (25.9+/-1.4 pg/ml) and placebo (23.5+/-1.3 pg/ml). DKCT did not alter the levels (about 5.7 pg/ml) of somatostatin. In conclusion, these results indicate that the action of DKCT closely relates to changes in motilin-immunoreactive substance levels in human plasma.

Tomograms of the arterial system of the human fetal auditory apparatus obtained by very-high-resolution microfocus X-ray CT and 3D reconstruction

A series of 500 tomograms and 3D reconstructions of the small arterial vessels of the human fetal auditory apparatus were obtained for the first time by employing very-high-resolution microfocus X-ray computed tomography (MFXCT, mu-CT) with injection of contrast medium into the fetal aorta. Contrast images were obtained with barium sulfate (BaSO4) but not with iopamidol (C17H12I3N3O8). The anterior, posterior, superior, and inferior tympanic arteries, internal carotid artery, internal auditory artery, deep auricular artery, and stylomastoid artery were identified on tomograms of a crown-rump length (CRL) 224-mm fetus. MFXCT tomograms of some arteries about 30 microns in diameter were successfully obtained by the present method despite the difficulty associated with injection of contrast medium into 40-year-old specimens that had been perfused with formalin. This procedure is very useful for making anatomical observations without subjecting the specimens to any mechanical stress.

Fcgamma receptor expression on hepatic macrophages and histological activity of chronic hepatitis

AIMS/BACKGROUND

Activated liver macrophages in chronic hepatitis express a high affinity receptor for IgG named FcgammaRI. This study was performed to find the difference in FcgammaRI expression between chronic hepatitis B (CHB) and C (CHC) with reference to histological activity.

METHODS

Consecutive patients with CHB (20 cases) and CHC (25 cases) were enrolled in the study. Inflammatory activity was evaluated using the modified histological activity index (HAI). FcgammaRI-positive macrophages were quantitatively measured by computer assisted morphometry.

RESULTS

Total HAI score was significantly higher in CHB than in CHC. Confluent necrosis was observed in significantly higher frequency in CHB at Stages 3 5 than in CHC. The percentage area of FcgammaRI-positive macrophages was significantly higher in CHB than in CHC. In CHB, the percentage area of FcgammaRI-positive macrophages correlated with total HAI (<0.01) as well as the degree of confluent necrosis (<0.01), interface hepatitis (<0.05) and portal inflammation (<0.05). FcgammaRI-positive macrophages accumulated mainly at the site of confluent necrosis. In CHC, no correlation was observed between activated macrophages and any histological categories.

CONCLUSION

These results suggest that FcgammaRI-positive macrophages are associated with confluent necrosis in CHB, which is more common in CHB patients than in CHC.

Dipeptides containing L-arginine analogs: new isozyme-selective inhibitors of nitric oxide synthase

Several L-arginine analogs are known as potent inhibitors of nitric oxide synthase (NOS). We recently synthesized dipeptides containing such amino acids, and found that they are potent and isozyme-selective NOS inhibitors. For example, S-methyl-L-isothiocitrullinyl-L-phenylalanine showed 66-fold selectivity for iNOS over nNOS, while S-methyl-L-isothiocitrullinyl-L-leucine and N(G)-nitro-L-argininyl-L-phenylalanine showed 20- and 14-fold selectivity, respectively. Interestingly, S-methyl-L-isothiocitrullinyl-D-phenylalanine showed no selectivity, and S-methyl-L-isothiocitrullinyl-L-phenylalanine showed competitive inhibition. These results suggest that each NOS isozyme has a cavity of different size near the C-terminal of the L-arginine binding site, and that the selectivity of inhibitors is due to the differences in the size of the cavity.

Imaging of caspase-3 activation in HeLa cells stimulated with etoposide using a novel fluorescent probe

Microscopic visualization of intracellular enzyme activity can provide information about the physiological role of the enzyme. Caspases are cysteine proteases that have critical roles in the execution of apoptosis. General fluorometric substrates of caspase-3, such as DEVD-MCA, are unsuitable for imaging because they are excited at short wavelength, so we designed and synthesized novel fluorescent probes that are excited at suitable wavelengths for detecting caspase-3 activity in living cells. Using one of these probes, we succeeded in microscopic visualization of caspase-3-like activity within HeLa cells treated with etoposide. The caspase-3-like activity was increased in the cytosol at first, then expanded to the whole cell.

Synthesis and evaluation of 1-position-modified inositol 1,4,5-trisphosphate analogs

IP3 analogs were synthesized by the modification of phosphate at the 1-position, and their affinity for the IP3 receptor was analyzed by means of surface plasmon resonance measurements. Our results suggest that a hydrophobic and charged moiety linked to this position enhances the affinity for the IP3 receptor.

Therapeutic angiogenesis induced by human recombinant hepatocyte growth factor in rabbit hind limb ischemia model as cytokine supplement therapy

Hepatocyte growth factor (HGF) exclusively stimulates the growth of endothelial cells without replication of vascular smooth muscle cells and acts as a survival factor against endothelial cell death. Therefore we hypothesized that a decrease in local vascular HGF might be related to the pathogenesis of peripheral arterial disease. We initially evaluated vascular HGF concentration in the vessels of patients with arteriosclerosis obliterans. Consistent with in vitro findings that hypoxia downregulated vascular HGF production, vascular HGF concentration in the diseased segments of vessels from patients with arteriosclerosis obliterans was significantly decreased as compared with disease-free segments from the same patients (P<0.05), accompanied by a marked reduction in HGF mRNA. On the other hand, a novel therapeutic strategy for ischemic diseases that uses angiogenic growth factors to expedite and/or augment collateral artery development has recently been proposed. Thus in view of the decreased endogenous vascular HGF, rhHGF (500 micrograms/animal) was intra-arterially administered through the internal iliac artery of rabbits in which the femoral artery was excised to induce unilateral hind limb ischemia, to evaluate the angiogenic activity of HGF, which could potentially have a beneficial effect in hypoxia. Administration of rhHGF twice on days 10 and 12 after surgery produced significant augmentation of collateral vessel development on day 30 in the ischemic model as assessed by angiography (P<0.01). Serial angiograms revealed progressive linear extension of collateral arteries from the origin stem artery to the distal point of the reconstituted parent vessel in HGF-treated animals. In addition, we examined the feasibility of intravenous administration of rhHGF in a moderate ischemia model. Importantly, intravenous administration of rhHGF also resulted in a significant increase in angiographic score as compared with vehicle (P<0.01). Overall, a decrease in vascular HGF might be related to the pathogenesis of peripheral arterial disease. In the presence of decreased endogenous HGF, administration of rhHGF induced therapeutic angiogenesis in the rabbit ischemic hind limb model, as potential cytokine supplement therapy for peripheral arterial disease.

Galardin inhibits collagen degradation by rabbit keratocytes by inhibiting the activation of pro-matrix metalloproteinases

We investigated the inhibitory action of a synthetic peptidyl hydroxamate inhibitor of matrix metalloproteinase (MMP), Galardin (GM6001), on collagen degradation by rabbit corneal stromal fibroblasts (keratocytes) cultured three-dimensionally in the type I collagen gel with medium containing interleukin 1alpha (IL-1alpha) and/or plasminogen. Degradation of collagen fibrils during culture was measured by the release of hydroxyproline, and activation of MMPs was also analyzed by gelatin zymography and Western blotting. Plasmin activity was measured using a synthetic substrate. In the absence of plasminogen, treatment of the cells with IL-1alpha in collagen gel greatly enhanced the production of proMMP-1, -3 and -9, but no significant degradation of collagen was detected. In the presence of plasminogen, IL-1alpha stimulated collagen degradation by keratocytes in a dose-dependent manner. This resulted from the plasminogen activator-plasmin system-dependent activation of proMMP-1, -3 and -9. Galardin inhibited the collagen degradation in a dose-dependent fashion in the presence of plasminogen, whether IL-1alpha was present or not. Galardin inhibited the activation of proMMP-3, and also prevented the activation of proMMP-9 and the conversion of MMP-1 intermediates to the fully active MMP-1. Galardin did not affect plasmin activity. The present results suggest that Galardin inhibits IL-1alpha-stimulated collagen degradation in the presence of plasminogen, resulting from not only inhibiting active MMPs but also preventing the conversion of proMMPs to active MMPs.

Skin cancer screening in Okinawa, Japan

Depletion of the ozone layer has been observed on a global scale. Ozone depletion increases the amount of biologically harmful solar ultraviolet radiation (UV) that reaches the surface of the Earth, leading to an increased incidence of skin cancer. We previously reported the prevalence and incidence of actinic keratosis (AK) in Kasai City, which is located almost at the center of Japan. To evaluate the effects of different ambient annual UV doses on the prevalence and incidence of non-melanoma skin cancer and AK in Japan, we screened for skin cancer on Ie Island in Okinawa at the southern end of Japan, where the annual cumulative dose of UV is assumed to be the highest in Japan. The island had a population of 5562 in 1993. A prospective 4-year population-based study on the prevalence and incidence of cutaneous neoplasms was conducted by examining the sun-exposed skin of people over 40 years of age living on Ie Island. In 1993 1996, 86 cases of AK, nine of basal cell carcinoma (BCC), and two of squamous cell carcinoma were identified. The annual prevalence of AK on Ie Island was 1159.4 in 1993, 572.8 in 1994, 1014.3 in 1995 and 988.9 per 100000 Japanese in 1996. These values were significantly higher than those in Kasai City. The annual age-adjusted odds ratios for AK of Ie Island to Kasai City were 2.79, 1.38, 2.45 and 2.39, respectively. The incidences of AK on Ie Island per 100,000 were 637.0 in 1995 and 625.5 in 1996, which were also significantly higher than those in Kasai City (223.6 in 1993 and 171.2 in 1994). The prevalence of BCC was 123.6 and the incidence was 26.1. Together with our previous reports, the present results show a possible inverse relationship between the prevalence and incidence of AK and latitude among Japanese people.