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Biomedical subjects

Y Nagao

Publications and source records attributed to Y Nagao.

At least 19 recordsLinked to original sources
PubMed2003

Evaluation of styrene oligomers eluted from polystyrene for estrogenicity in estrogen receptor binding assay, reporter gene assay, and uterotrophic assay.

Styrene dimers (SDs) and styrene trimers (STs) eluted a little from polystyrene have been suspected of having estrogenic activity in the Wingspread Declaration [Our Stolen Futures, 1996] despite the lack of scientific analysis. Therefore, we have studied and reported styrene oligomers to have no endocrine disrupting effects [J. Food Hygienic Soc. Japan 40 (1999) 36; 41 (2000) 109; Yuki Goseikagaka Kyokaishi 57 (1999) 58; Bunseki Kagaku 49 (2000) 493, 857; Food Chem. Toxicol. 39 (2001) 1233; 40 (2002) 129]. However, Ohyama et al. reported that certain styrene oligomers have estrogenic effects in E-SCREEN and estrogen receptor (ER) binding assay [Environ. Health Perspect. 109 (2001) 699]. Recently, several assay systems have been developed, and a few of them can show false positive reactions at the high concentrations to which test compounds are precipitated [J. Health Sci. 48 (2002) 83]. In order to assess the estrogenic effect of SDs and STs in more detail, we examined the accuracy of the binding assay system and tested SDs and STs by three types of ER binding assay. In one ER binding assay, the same method that Ohyama et al. performed, SDs and STs showed a little estrogenic activity at high concentration; they did not dissolve, but this assay system tended to detect false positive effects at high concentration. In contrast, in the other assay systems, SDs and STs did not show any binding affinity to ER. In addition, luciferase reporter gene assay in HeLa cells transfected with ER expression plasmid and reporter plasmid, as a newly developed standard assay, and immature rat uterotrophic assay were conducted. In these tests, styrene oligomers showed no estrogenic activity.

Animals↗
PubMed2002

High prevalence of anticardiolipin antibodies in patients with HCV-associated oral lichen planus.

Hepatitis C virus (HCV) has been linked to extrahepatic manifestations such as oral lichen planus (OLP). In addition, anticardiolipin antibodies (aCL) and cryoglobulin have been demonstrated in chronic hepatitis C. The aim of this study was to investigate these prevalences in patients with HCV-associated OLP. The prospective study investigated the role of these factors in 133 subjects: 28 with OLP-HCV(+) (group 1), 22 with OLP-HCV(-) (group 2), 33 without OLP-HCV(+) (group 3), and 50 healthy volunteers matched for age and sex served as control group (group 4). Levels of immunoglobulin G (IgG) and IgM aCL antibodies, and cryoglobulin in serum were evaluated by enzyme-linked immunosorbent assay. The prevalence of aCL in groups 1, 2, 3, and 4 were 32.1, 18, 36.3, and 8%, respectively. The positive rate of aCL was significantly higher in groups 1 and 3 than that in the control group (group 1; p=0.02 vs. the control group, group 3; p<0.01 vs. the control group). There were no significant differences in cryoglobulin among the groups. The findings of the present study showed a high prevalence of IgG and IgM aCL in the serum of patients with HCV infectious diseases. A positive factor for aCL was determined by age, sex, the presence of OLP, and HCV infection.

Adult↗
PubMed2002

The possible intraspousal transmission of HCV in terms of lichen planus.

Lichen planus (LP), common mucocutaneous disorder, involves not only oral mucosa and skin but genitalia membrane. LP is frequently seen in patients with HCV infection. This study evaluated patients with HCV-associated oral lichen planus (OLP) for vulvar and vaginal LP involvement, and the possible intraspousal transmission of HCV. We examined a total of 24 female Japanese patients with OLP for genitalia LP: 14 OLP-HCV positive and 10 OLP-HCV negative. All subjects were evaluated for genital LP by a gynecologist. All 24 subjects and 10 of the husbands were tested for anti-HCV and serum HCV RNA. Vulvar LP was observed in 10 (41.7%) of 24 patients with OLP. Vulvar LP in 14 (OLP-HCV positive) and 10 patients (OLP-HCV negative) were observed in 42.9 and 40%, respectively. There were no significant differences (age, sites of OLP, blood transfusion, HCV infection, and degree of liver diseases) between the vulvar LP and non-vulvar LP patients. Two spouses of 10 married couples were shown to be infected with HCV. In one couple with HCV infection, the wife and husband had also erosive OLP, the wife had erosive vulvar LP. In conclusion, the majority of OLP patients suffered from genitalia LP in Japan. Clinicians should follow the OLP patients with sufficient attention to the presence of extraoral manifestations. These data may suggest the occurrence of intraspousal transmission of HCV through erosive vulvar LP.

Adult↗
PubMed2001

A case of muscular hamartoma of the breast.

We describe a 74-year-old female presenting with a right breast mass. She had found the mass on self-examination. Physical examination revealed a 2.2 x 2.5 cm, firm, smooth, and mobile lump in the upper medial portion of the right breast. Mammography revealed a well marginated, oval-shaped, and isodense nodule. Calcification was not evident. On ultrasonography, the lesion was 17 x 18 x 9 mm and located 5 mm below the overlying skin. Excisional biopsy under local anesthesia was performed. The tumor was easily excised. Histopathologically, the lesion was composed of intersecting bundles of spindle-shaped smooth muscle cells, and involved peripheral ducts and fat tissue. Immunohistochemical staining showed positivity for alpha-smooth muscle actin (SMA), but was negative for S-100 protein, myoglobin, keratin, and vimentin. From these findings a muscular hamartoma of the breast, a rare subtype of hamartoma, was diagnosed.

Aged↗
PubMed2001

Retreatment with interferon-alpha at dosages or period increased by 1.3 times is effective for treatment for transient responders and non-responders in chronic hepatitis C patients.

The objectives of retreatment with interferon (IFN) in chronic hepatitis C (CH-C) patients are sustained response and a reduction in the risk of hepatocellular carcinoma (HCC). However, it is still unclear, as to which patients are candidates for retreatment with IFN. Eighteen transient responders (TRs) and 15 non-responders (NRs) to IFN therapy in CH-C received retreatment with IFNalpha. Of the 18 TRs, five showed sustained disappearance of hepatitis C virus, two showed sustained biochemical response, 10 continued as TR and one was a NR. Of the 15 NRs, six showed a TR while nine continued as NRs. Responsive cases, which included the virologically or biochemically sustained and transient responders, received either a dose of IFN 1.3 times greater or were treated for a period of 1.3 times longer in the retreatment than the original treatment. We submit that IFN treatment consisting of either a time period or a dosage 1.3 times those of the original IFN administration may be beneficial in the case of TR and NR in chronic hepatitis C patients.

Journal Article↗
PubMed2001

Identification, determination, and biological evaluation of a novel styrene trimer contained in polystyrene food containers. 2.

An unidentified styrene trimer (ST) isolated from the acetonitrile extract of polystyrene (PS) food containers was characterized as (1S*,6R*,7S*,8S*,11R*)-6,11-diphenyltricyclo[6,2,2,0(2,7)]dodeca-2,9-diene. The content and migration of this compound in PS food containers were determined by GC-MS (SIM). Furthermore, an endocrine-disrupting effect was tested using in vitro and in vivo assays of the compound. In conclusion, it seems that the compound does not present the effect.

Animals↗
PubMed2001

Time course profile and cell-type-specific production of monokine induced by interferon-gamma in Concanavalin A-induced hepatic injury in mice: comparative study with interferon-inducible protein-10.

BACKGROUND: We have previously shown that interferon-inducible protein-10 (IP-10), a chemokine for activated lymphocytes, was specifically induced in the liver of Concanavalin A (Con A)-treated mice. The aim of this study was to investigate the time course profile and cell-type-specific hepatic production of monokine induced by interferon-gamma (MIG), a chemokine which shares its receptor and most of its activity with IP-10, in Con A-treated mice and to compare them with those of IP-10. METHODS: Hepatic mRNA expression of MIG and IP-10 was studied by means of Northern blot analysis and in situ hybridization in Con A-treated mice. The levels of MIG and IP-10 in the serum and culture supernatants of murine hepatoma-, hepatic sinusoidal endothelial cell-, hepatic stellate cell- and macrophage-derived cell lines were determined by means of specific enzyme-linked immunosorbent assays. RESULTS: The serum level of MIG slowly reached a maximum at 12 h after Con A injection and remained elevated for a long time, whereas that of IP-10 reached a maximum at 3 h and declined quickly, a finding supported by Northern blot analysis. Using in situ hybridization, the mRNA of MIG as well as IP-10 was found to be expressed in hepatocytes and hepatic non-parenchymal cells. Similar to IP-10, MIG was produced by hepatoma-, hepatic sinusoidal endothelial cell-, hepatic stellate cell- and macrophage-derived cell lines in vitro. CONCLUSIONS: Although both MIG and IP-10 were produced by hepatocytes and hepatic non-parenchymal cells in Con A-treated mice, the time course profile of MIG was distinguishable from that of IP-10. The fact that hepatic MIG and IP-10 were produced sequentially in this hepatitis model may suggest that a non-redundant role is played by these two chemokines in the process of hepatic necro-inflammation.

Animals↗
PubMed2001

Synthesis and antibacterial activity of new 1beta-methylcarbapenems having the potential for intramolecular nonbonded S...O interactions.

Mercaptoacetyliminothiadiazoline derivatives (19, 20) useful for the pendant moiety of 1beta-methylcarbapenem antibiotics were efficiently synthesized. Acetyl derivative (18) of 20 was submitted to X-ray analysis, and a significant nonbonded S...O close contact was recognized in the crystallographic structure. New 1beta-methylcarbapenems (5, 6) were synthesized by exploiting 19 and 20, and exhibited considerable antibacterial activities in vitro.

Anti-Bacterial Agents↗
PubMed2001

Establishment of a simple method for measurement of chronic blood flow in uterine artery of pregnant cows.

Blood flow to the gravid uterine horn of seven multiparous Holstein cows (mean +/- SD, BW = 625.5 +/- 82.4 kg; age = 4.7 +/- 1.7 yr; parity = 2.9 +/- 1.1 yr) was measured from d 225 of gestation to parturition using transit-time ultrasonic blood flow probes placed around the middle uterine artery. Surgery was conducted on d 215 of gestation. The cows were sedated with xylazine and local anesthesia (procaine or bupivacain hydrochloride) during surgery. The surgical operations were conducted at the flank of standing cows. A transit time ultrasonic flow probe ("S" series, diameter 12 or 14 mm, Transonic Systems Inc., Ithaca, NY) was fitted surgically around the uterine artery of each cow. Surgery was completed within 2 h of anesthesia, and the animals recovered rapidly following surgery. Uterine blood flow (UBF, L/min) was recorded at 10-s intervals for 1395 min; these values were averaged to determine UBF. Cows exhibited normal gestation lengths (279.1 +/- 7.4 d), gave birth to normal healthy calves (birth weight = 40.6 +/- 6.6 kg), and had no retained placentas. The UBF increased significantly (P < 0.01) from d 225 (6.67 +/- 2.47) to d 249 (8.23 +/- 2.89) of gestation, but the latter UBF was similar to that of d 266 (8.38 +/- 2.70). The increased UBF after d 225 indicates increased demand of nutrients of fetus with the progress of gestation. The range of mean UBF varied widely among individual cows from 4.1 L/min to 12.2 L/min. Our method is useful for chronic measurement of UBF in cows for nutritional or physiological studies and does not require sophisticated facilities or special surgical technique.

Animals↗
PubMed2000

Glycine-rich region of mitochondrial processing peptidase alpha-subunit is essential for binding and cleavage of the precursor proteins.

Mitochondrial processing peptidase, a metalloendopeptidase consisting of alpha- and beta-subunits, specifically recognizes a large variety of mitochondrial precursor proteins and cleaves off amino-terminal extension peptides. The alpha-subunit has a characteristic glycine-rich segment in the middle portion. To elucidate the role of the region in processing functions of the enzyme, deletion or site-directed mutations were introduced, and effects on kinetic parameters and substrate binding of the enzyme were analyzed. Deletion of three residues of the region, Phe(289) to Ala(291), led to a dramatic reduction in processing activity to practically zero. Mutation of Phe(289), Lys(296), and Met(298) to alanine resulted in a decrease in the activity, but these mutations had no apparent effect on interactions between the two subunits, indicating that reduction in processing activity is not due to structural disruption at the interface interacting with the beta-subunit. Although the mutant enzymes, Phe289Ala, Lys296Ala, and Met298Ala, had an approximate 10-fold less affinity for substrate peptides than did that of the wild type, the deletion mutant, delta 289-291, showed an extremely low affinity. Thus, shortening of the glycine-rich stretch led to a dramatic reduction of interaction between the enzyme and substrate peptides and cleavage reaction, whereas mutation of each amino acid in this region seemed to affect primarily the cleavage reaction.

Amino Acid Sequence↗
PubMed2000

DMSO and glycerol reduce bacterial death induced by expression of truncated N-terminal huntingtin with expanded polyglutamine tracts.

Huntington's disease (HD) is caused by CAG repeat expansion in exon 1 of a large gene, IT15, possessing 67 exons. Transgenic mice expressing a truncated N-terminal peptide of huntingtin with an expanded polyglutamine tract translated only from exon 1 develop symptoms similar to Huntington's disease. In the present study, a bacterial system (Escherichia coli) was used to express truncated peptides of huntingtin translated from exon 1 of the HD gene. Bacterial death was observed after the induction of peptides with expanded polyglutamine tracts, and both sodium dodecyl sulfate (SDS)-soluble peptides and insoluble aggregated material were detected by immunoblotting in the homogenates of such E. coli. E. coli death was partially reduced by the addition of dimethylsulfoxide (DMSO) or glycerol to the medium, with a consequent decrease in aggregated material and an increase in SDS-soluble peptide in the homogenate. These results suggest that DMSO and glycerol may decrease the toxicity of huntingtin with expanded polyglutamine tracts by acting as chemical chaperones.

Animals↗
PubMed2000

Anti-stress effects of DHA.

DHA is abundant in the brain. Deficiency of DHA changes behavior in animals. The purpose of the present studies was to clarify the effect of DHA intake on hostility and plasma catecholamines. In study 1, forty-one students took either DHA-rich oil capsules containing 1.5-1.8 g DHA/d (17 females and 5 males) or control oil capsules containing 97% soybean oil plus 3% fish oil (12 females and 7 males) for 3 mon in a double blind fashion. They took a psychological test (P-F Study) at the start and end of the study. Study I started at the end of summer vacation and ended in the middle of mental stress of final exams. In the control group, hostility measured by P-F Study was significantly increased at the end of the study as compared with that measured at the start (+58%), whereas it was not significantly changed in the DHA group (-14%). In a similar double blind two-mon study (study 2), we measured plasma catecholamines and cortisol of students (3 females and 4 males for the DHA group and the same numbers for the control) at the start and end of the study. In study 2 the students were under a continuous stress of final exams that lasted for two mon throughout the whole study period. The plasma cortisol did not change in either group, but the norepinephrine concentration was significantly decreased in the DHA group (-31%), whereas it stayed at the same level in the control group. These effects of DHA intake may be applied to people under psychological stress.

Adult↗
PubMed2000

Dexamethasone enhances mallory body formation in drug-primed mouse liver.

In a clinical study in which patients with alcoholic hepatitis were treated with prednisone for 1 month, posttreatment liver biopsies showed diminished inflammation, but Mallory bodies were not diminished. This suggested that steroid treatment may reduce inflammation by inhibiting NFkappaB activation. Sparing of Mallory bodies suggests that NFkappaB activation may not be involved mechanistically in Mallory body formation. To test this idea, we induced Mallory body formation in drug-primed mice with or without dexamethasone treatment. As predicted, dexamethasone decreased NFkappaB activation; however, Mallory body formation was increased. Surprisingly, TNFalpha and iNOS, which normally increase as a result of NFkappaB activation, were upregulated by the dexamethasone treatment. It was concluded that NFkappaB activation is not involved in Mallory body formation. Despite this, induced increases in TNFalpha, iNOS, c-jun/API and c-myc expression indicate that oxidative stress is likely involved in Mallory body formation.

Animals↗
PubMed2000

Urinary trypsin inhibitor reduces C-X-C chemokine production in rat liver ischemia/reperfusion.

BACKGROUND AND AIM: Protease inhibitors attenuate ischemia/reperfusion injury. However, the underlying mechanisms by which protease inhibitors prevent reperfusion injury remain obscure. Neutrophils play an important role in reperfusion injury. We studied the effects of urinary trypsin inhibitor (UTI) on production of the C-X-C chemokine, cytokine-induced neutrophil chemoattractant (CINC), by Kupffer cells during ischemia/reperfusion of the liver. METHODS: Liver ischemia was induced in rats by occlusion of the portal vein for 30 min. UTI (50,000 U/kg) was injected intravenously 5 min before vascular clamping. Serum CINC concentrations were measured by enzyme-linked immunosorbent assay. Levels of CINC mRNA in the liver were determined by Northern blot analysis. We also examined the inhibitory effects of UTI on in vitro CINC production by peritoneal macrophages in response to neutrophil elastase (NE). RESULTS: Serum CINC concentrations increased and peaked 6 h after reperfusion. However, pretreatment of animals with UTI blunted this increase in CINC and significantly reduced CINC mRNA levels in the liver after ischemia/reperfusion. UTI also decreased neutrophil accumulation in the liver 24 h after reperfusion. In vitro CINC production by Kupffer cells from rats pretreated with UTI 3 h after ischemia/reperfusion was significantly decreased compared to those from untreated animals. UTI reduced NE activity in vitro in a dose-dependent manner, and UTI significantly reduced in vitro CINC production by peritoneal macrophages stimulated with NE. CONCLUSION: UTI reduces the production of CINC by Kupffer cells stimulated with NE, attenuating ischemia/reperfusion injury of the liver.

Alanine Transaminase↗
PubMed2000

Histopathological and immunohistochemical study of oral lichen planus-associated HCV infection.

Background: In recent years, it has been suggested that oral lichen planus (OLP), a chronic inflammatory keratotic lesion, is related to hepatitis C virus (HCV) infection. Therefore, we evaluated whether the presence or absence of HCV infection caused any histopathological differences in OLP tissues. Methods; The subjects consisted of 31 patients with HCV-related liver disease complicated by OLP (32 OLP lesions) and ten OLP patients without complications due to either HCV infection or liver disease (control). A histopathological evaluation was performed in these patients. In addition, immunostaining was done on nine OLP tissues infected with HCV and on six OLP tissues without HCV infection in order to evaluate lymphocyte subsets (T cells or B cells) infiltrating into topical regions with OLP. Furthermore, the severity of hepatic fibrosis and inflammation was evaluated in liver tissues obtained by liver biopsy from six patients with HCV-related liver disease to evaluate whether there were any relationships between the severity of hepatic fibrosis or inflammation and OLP tissues. Results: There were no significant differences in the histopathological characteristics specific to OLP or in the ratios of T and B cells among infiltrating lymphocytes regardless of the presence or absence of HCV infection. Moreover, there were no certain relationships between the severity of hepatic fibrosis or inflammation and the severity of lymphocytic infiltration in OLP. Conclusions: HCV infection does not appear to influence the histopathological and immunohistochemical features of OLP.

Journal Article↗