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N Katoh

Publications and source records attributed to N Katoh.

At least 19 recordsLinked to original sources

Effect of serotonin on the differentiation of human monocytes into dendritic cells.

The local cytokine environment and presence of stimulatory signals determine whether monocytes acquire dendritic cell (DC) or macrophage characteristics and functions. Because enhanced platelet activation is reported in patients with many allergic disorders, such as atopic dermatitis, platelet-derived factors may influence monocytic differentiation into DC. In this study we examined the effect of serotonin, a prototypic mediator of allergic inflammation released mainly by activated platelets at the inflammatory site, on the granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4-driven differentiation of monocytes into monocyte-derived DC. Monocytes from healthy adult donors were cultured with GM-CSF and IL-4 in the presence or absence of serotonin, and the phenotypes and function of these cells were analysed. In the presence of serotonin, monocytes differentiated into DC with reduced expression of co-stimulatory molecules and CD1a, whereas expression of CD14 was increased. These serotonin-treated DC exhibited significantly reduced stimulatory activity toward allogeneic T cells. However, these cells showed enhanced cytokine-producing capacity, including IL-10 but not IL-12. There was no significant difference between both types of DC in phagocytic activity. Experiments using agonists and antagonists indicated that serotonin 5-hydroxytryptamine (5-HT) induced the alteration of their phenotype and reduction in antigen-presenting capacity were mediated via 5-HTR(1/7). It is therefore suggested that serotonin-driven DC may have a regulatory function in the inflammatory process.

Adult↗

The role of interleukin-16 in murine contact hypersensitivity.

Contact hypersensitivity (CHS) is a T-cell-mediated skin inflammatory response. It is controversial whether CD4(+) T cells play an enhancing or regulatory role in the pathogenesis of CHS. Because interleukin (IL)-16 is a chemoattractant cytokine for CD4-expressing cells, we investigated the involvement of IL-16 in the CHS reaction. IL-16 production was induced in the epidermis and dermis during the elicitation phase of the CHS response with trinitrochlorobenzene. In the sensitization phase, the single application of haptens such as trinitrochlorobenzene and oxazolone also induced IL-16, whereas primary irritants or vehicle control did not. IL-16 was produced mainly by CD11c-negative cells in the epidermis during the elicitation phase. Furthermore, treatment of sensitized mice with anti-IL-16 neutralizing MoAb enhanced the ear swelling and reduced the number of infiltrating CD4(+) T cells. These data indicate that IL-16 plays a role in CHS, whereby IL-16 induces CD4(+) T cells and these CD4(+) T cells subsequently exhibit down-regulating properties.

Animals↗

Epidemiology of blood donors in Japan, positive for hepatitis B virus and hepatitis C virus by nucleic acid amplification testing.

BACKGROUND AND OBJECTIVES: The Japanese Red Cross screens seronegative blood donors by nucleic acid amplification testing (NAT) for hepatitis B, hepatitis C and human immunodeficiency virus-1 markers. NAT-positive donors thus identified seemed to have a different infectious background from serologically positive donors. The purpose of our study was to characterize this background in the hepatitis B virus (HBV) and hepatitis C virus (HCV) NAT-positive donors. MATERIALS AND METHODS: Some 328 HBV DNA-positive and 44 HCV RNA-positive donors were detected by NAT testing of seronegative blood donors. These were characterized regarding age, gender and genotype of HBV and HCV. RESULTS: Those who were HBV NAT-positive were mainly young, in particular teenage girls. In Japan, genotypes C and B have previously been dominant, but recently genotype A has increased, and genotype H was recently detected. In HBV NAT-positive donors, the rate of genotype A was high (12.2%) compared with patients in hospital (1.7-2%). Donors who were HCV NAT-positive were also young, but mostly men in their twenties. The ratio of genotype 1b to 2a or 1b to 2b in HCV NAT-positive donors differed from that of hospitalized patients in Japan. We did not find genotype 1a, which is dominant in the USA. CONCLUSIONS: The high-risk donors detected by NAT were mainly young, with a different distribution of genotypes from that of hospitalized patients, regarding both HBV and HCV. The rare HBV genotype H has been found for the first time in Japan. The findings reflect the present spread of hepatitis viruses B and C.

Adolescent↗

Incidence of insulin resistance in obese subjects in a rural Japanese population: the Tanno and Sobetsu study.

OBJECTIVES: Although it is well known that obesity is closely related to insulin resistance, the incidence of the development of insulin resistance in people with obesity is not known. In this study, we investigated the incidence of insulin resistance in citizens of two rural communities in Japan. SUBJECTS AND METHODS: The subjects were 102 men and 126 women over the age of 30 years selected from 1035 citizens who had undergone medical examinations in the towns of Tanno and Sobetsu, Hokkaido, in 1991 and 1998. Those who were on medication for hypertension, diabetes, hyperlipidaemia, coronary heart disease and cerebral vessel disease were excluded. The simple index to determine insulin resistance [i.e. homeostasis model assessment (HOMA-R) > or = 1.73] was used, and subjects who were determined to be positive for insulin resistance according to this index in 1991 were also excluded in order to determine the incidence of insulin resistance in subjects who had no abnormalities other than obesity. The systolic blood pressure (SBP), diastolic blood pressure, body mass index (BMI), triglyceride level, high-density lipoprotein level, blood sugar level, serum insulin value and HOMA-R were measured in all subjects in 1991 and in 1998. Moreover, the subjects were divided into two groups according to BMI, a normal group consisting of subjects with BMI < 25 and an obesity group consisting of subjects with BMI > or = 25. We also compared the incidences of insulin resistance in normal and obesity groups of subjects who were newly determined to be positive for insulin resistance on the basis of data obtained from medical examinations conducted in 1998. RESULTS: The incidence of insulin resistance was significantly higher in the obesity group than in the normal group (25.0 vs. 4.5%). The results of logistic regression analysis showed that obesity was closely related to insulin resistance and that the relative risk of development of insulin resistance adjusted for age, sex, SBP, FPG and HDL was 3.193 (95% CI 1.085-9.401). CONCLUSIONS: The incidence of insulin resistance was significantly higher in the obesity group than in the normal group in this study, suggesting that improvement in obesity is important for prevention of the occurrence of type 2 diabetes or atherosclerotic disease based on insulin resistance.

Adult↗

Granulocyte colony-stimulating factor-producing cutaneous angiosarcoma with leukaemoid reaction arising on a burn scar.

We report a 46-year-old man with a giant tumour in a burn scar on his buttock. Pathological examination revealed that the dermis was filled with anastomosing vascular channels and round- or spindle-type atypical cells, which were compatible with the diagnosis of cutaneous angiosarcoma. Based on prominent leucocytosis (up to 113 000 microL-1), we measured serum granulocyte colony-stimulating factor (G-CSF). The highly elevated serum G-CSF of 303 ng L-1 (normal, 6.1-21.5 ng L-1) and positive immunohistochemical staining of the tumour tissue for G-CSF indicated that G-CSF was produced by the cutaneous angiosarcoma. To our knowledge, this is the first reported case of G-CSF-producing cutaneous angiosarcoma.

Adult↗

Cutaneous sarcoidosis successfully treated with topical tacrolimus.

Sarcoidosis is a disorder characterized by macrophage- and T-cell-mediated responses to as yet unidentified infectious antigens or autoantigens. We describe a 62-year-old woman with a 10-year history of orange-yellow plaques of sarcoidosis on her face. Her cutaneous lesions responded to topical tacrolimus ointment after unsuccessful treatment with topical and systemic corticosteroids. No adverse effects were noted with topical tacrolimus in this patient. We discuss the mode of action by which this immunosuppressive agent may act against sarcoidosis.

Facial Dermatoses↗

Increased levels of serum tissue inhibitor of metalloproteinase-1 but not metalloproteinase-3 in atopic dermatitis.

Matrix metalloproteinases and their specific inhibitors, tissue inhibitors of metalloproteinases (TIMPs), contribute to inflammation-induced tissue destruction and subsequent remodeling for maintenance of tissue homeostasis. Since the production of these enzymes and their inhibitors is regulated by mediators such as proinflammatory cytokines and growth factors, elevated levels of serum TIMPs and/or MMPs have been documented in patients with several inflammatory disorders. In this study, we examined the role of TIMPs and MMPs in the pathogenesis of atopic dermatitis (AD) by evaluating the serum levels of TIMP-1 and MMP-3 in 40 patients with AD and 20 control subjects by ELISA. The serum TIMP-1 levels were significantly higher in AD patients in exacerbation status than in nonatopic subjects, whereas serum MMP-3 levels were not significantly different between them. As a result, AD patients revealed significantly elevated TIMP-1/MMP-3 ratios. The levels of serum TIMP-1 were significantly reduced in AD patients following conventional treatments. Significantly higher values of peripheral eosinophil counts, serum levels of IgE and lactate dehydrogenase, eruption score, and eruption area were noted in the AD patients with elevated TIMP-1 levels when compared with those with normal values. Moreover, the points of chronic eruptions such as lichenification and prurigo were significantly higher in the patients with elevated TIMP-1 levels than those with normal TIMP-1, while those of acute lesions such as oozy/microvesicles and oedema were not different between these groups. Serum TIMP-1 level may be a useful marker to estimate the long-term disease activity of AD.

Adolescent↗

Engagement of Fc epsilon RI on human monocytes induces the production of IL-10 and prevents their differentiation in dendritic cells.

The local cytokine environment and the presence of stimulatory signals determine whether circulating monocytes will finally acquire characteristics of dendritic cells (DCs) or macrophages. Because FcepsilonRI expressed on professional APCs, e.g., monocytes and DCs, has been suggested to play a key role in the pathophysiology of atopic diseases, we evaluated the effect of receptor ligation on the generation of monocyte-derived DCs (MoDCs). Aggregation of FcepsilonRI at the initiation of the IL-4-GM-CSF-driven differentiation resulted in the emergence of macrophage-like cells with a strong expression of the mannose receptor and a low level of CD1a and the DC-specific markers CD83 and the actin-bundling protein (p55). These cells sustained the ability to take up FITC-labeled Escherichia coli by phagocytosis and were significantly less efficient in stimulating purified allogeneic T cells. In addition, receptor ligation of FcepsilonRI at the beginning of the culture prevented the generation of MoDCs, mainly due to a dramatic increase in the IL-10 production. These results suggest that FcepsilonRI aggregation prevents the generation of CD1a(+) MoDCs and imply a novel pivotal function of this receptor in modulating the differentiation of monocytes.

Cell Differentiation↗

Different effects between 7-nitroindazole and L-NAME on cerebral hemodynamics and hippocampal lesions during kainic acid-induced seizures in newborn rabbits.

We examined the effects of 7-nitroindazole (7-NI) and N-omega-nitro-L-arginine methyl ester (L-NAME) on the endogenous nitric oxide (NO) production in vivo, cerebral hemodynamics, and hippocampal lesions to investigate the different roles between endothelial NOS (eNOS) and neuronal NOS (nNOS) during kainic acid (KA)-induced seizures in newborn rabbits. After a pre-treatment with 7-NI (50 mg/kg, i.p.), L-NAME (20 mg/kg, i.v.) or saline (1 ml, i.v.), KA (12 mg/kg, i.v.) was administered. NO production in the brain, regional cerebral blood flow (rCBF), cerebral oxygenation (concentrations of oxyhemoglobin (HbO2), deoxyhemoglobin (HbR), and total hemoglobin (tHb) in the brain tissue), and electroencephalography (EEG) were continuously monitored throughout the experiment lasting at least 60 min after the KA administration. There was a significant increase in NO generation in the brain during KA-induced seizures, which was inhibited by a pre-treatment with 7-NI or L-NAME. KA-induced seizures also increased rCBF significantly, which was inhibited not by 7-NI but by L-NAME. L-NAME pre-treatment caused a significant decrease in HbO2 and a significant increase in HbR during KA-induced seizures, compared with 7-NI and saline pre-treatment. EEG abnormalities and Neuronal damages in the hippocampus were significantly lower in 7-NI- and L-NAME-treated animals respectively, than in saline-treated animals. The present data demonstrated that the selective nNOS inhibitor, 7-NI, attenuated neither rCBF nor cerebral oxygenation during the seizures, while the non-selective NOS (nNOS and eNOS) inhibitor, L-NAME, attenuated both. These findings suggest that NO, probably originating from eNOS, may play an important role in the cerebral circulation. Both 7-NI and L-NAME inhibited the NO production and EEG abnormalities during the seizures that led to less damage to the hippocampus.

Animals↗

Reduction in serum lecithin:cholesterol acyltransferase activity in natural cases of pneumonia in calves.

In experimental calf pneumonia induced by inoculations of Pasteurella haemolytica or bovine herpesvirus-1, lipoprotein lipid concentrations and lecithin:cholesterol acyltransferase (LCAT) activity decrease. The purpose of this study was to examine whether similar changes in lipoproteins occur in natural cases of calf pneumonia. When monitored in a time-course study, the activity of LCAT, and the concentrations of free cholesterol, cholesteryl esters, phospholipids and triglycerides were steadily decreased. No significant decreases in LCAT activity or lipid concentrations were detected in sera from cows with mastitis. These results, coupled with the previous findings on experimental calf pneumonia, indicate that, while decreases in LCAT activity and the LCAT-related lipid concentrations are involved in the pathogenesis of calf pneumonia, this is not the case for all inflammatory diseases.

Animals↗

Cortical lens opacification in Iceland. Risk factor analysis -- Reykjavik Eye Study.

PURPOSE: Cortical lens opacification has been associated with outdoor exposure and UV radiation more than other types of lens opacification. We studied risk factors for cortical lens opacification only, the most common as well as the earliest age related change we observe in the lens. METHODS: 1,045 persons, 583 females and 462 males, 50 years and older, underwent a detailed eye examination and answered a questionnaire. Participants with cortical lens opacification grade I, totalling 374 persons, were assigned to case-control study I, and to case-control study II those with cortical lens opacification grades II and III, totalling 82 subjects. 378 age and sex matched persons served as controls. RESULTS: Those who spent more than 4 hours/day outside on weekdays, in their 20's--30's and 40's--50's respectively, were found to have increased risk of moderate to severe cortical lens opacification. Thus the relative risk for grades II & III, was 2.80 (95% CI 1.01--7.80) and 2.91 (95% CI 1.13--9.62) respectively. Ageing and systemic cortical steroids use were also found to be risk factors. CONCLUSION: Outdoor exposure appears to be associated with increased risk of moderate to severe cortical lens opacification. Ageing is, however, the main risk factor.

Aged↗

Decreased concentration of serum apolipoprotein C-III in cows with fatty liver, ketosis, left displacement of the abomasum, milk fever and retained placenta.

Apolipoprotein (apo) C-III is a low molecular mass protein mainly distributed in the high-density lipoprotein (HDL) fraction. In cows with postparturient diseases such as ketosis, concentrations of cholesterol, phospholipids and apoA-I and the activity of lecithin:cholesterol acyltransferase, which are mainly distributed in or functionally associated with HDL, are reduced. The purpose of the present study was to examine whether the serum concentration of apoC-III was similarly decreased in the postparturient diseases. Compared with healthy controls, the apoC-III concentration was significantly (P<0.01) decreased in cows with fatty liver, ketosis, left displacement of the abomasum, milk fever and retained placenta. Concentrations of apoC-III in the HDL fractions from diseased cows were also lower than in controls. Of the diseased cows, the decreased apoC-III concentration was particularly distinct in cows with milk fever. Increased nonesterified fatty acid and reduced free cholesterol, cholesteryl ester and phospholipid concentrations were observed in cows with milk fever, as in the other diseased cows. The decrease in the apoC-III concentration is suggested to be closely associated with the postparturient disorders, in particular with milk fever.

Abomasum↗

Concentrations of apolipoprotein C-III in healthy cows during the peripartum period and cows with milk fever.

Apolipoprotein (apo) C-III is a low-molecular-mass protein mainly distributed in the high-density lipoprotein fraction in cattle serum. We have recently shown that the apoC-III concentration is decreased in cows with fatty liver, ketosis, left displacement of the abomasum, retained placenta and milk fever. The decrease was most distinct in milk fever, thereby suggesting that apoC-III is particularly relevant to the development of milk fever and also that apoC-III is a candidate diagnostic marker for this disease. The purpose of the present study was to examine whether the apoC-III concentration in healthy cows is altered during the peripartum period, to assess the usefulness of apoC-III as a marker for milk fever. ApoC-III concentrations in 17 cows were monitored during the peripartum period (-48 to +12 days from parturition). Of the 17 cows, 14 were apparently healthy during the period. The apoC-III concentrations in the 14 healthy cows were unaltered during the period from -48 to -21 days, but thereafter showed individual variations. Compared with values during the period from -48 to -21 days, the apoC-III concentration was increased (137%) in 5 cows during the period from +1 to +12 days, whereas it decreased (60.7%) in 9 cows. Three cows suffered from milk fever at -3 to +10 days. Decreased apoC-III concentrations in diseased cows (15 to 37% of controls) were more distinct than in the 9 healthy cows. The apoC-III concentration was correlated with lecithin:cholesterol acyltransferase activity in cows with milk fever, but not in healthy cows. Correlation analysis also indicated that apoC-III and apoB-100 concentrations were negatively correlated in 5 healthy cows with increased apoC-III concentrations, but positively in 9 healthy cows with decreased concentrations and cows with milk fever. Determination of the apoC-III concentration during the peripartum period is suggested to be helpful in diagnosing milk fever. The possible relevance of apoC-III and apoB-100 in the development of milk fever is also implied.

Animals↗

Analysis by enzyme-linked immunosorbent assay and 2-dimensional electrophoresis of haptoglobin in the high-density lipoprotein fraction in cows.

Haptoglobin (Hp) is a hemoglobin (Hb)-binding acute-phase protein. Besides its relevance in inflammation, Hp is involved in the regulation of lipid metabolism. In cattle, in addition to the lipoprotein-deficient fraction, Hp is distributed in high-density lipoprotein (HDL) and very high-density lipoprotein (VHDL) fractions. The purpose of this study was to determine Hp concentrations in the lipoprotein fractions using an enzyme-linked immunosorbent assay (ELISA) based on the affinity with Hb, and also to detect structural differences of HDL Hp from that in the lipoprotein-deficient fraction using 2-dimensional electrophoresis. When purified Hp was used as the antigen for the ELISA, the detection limit was 7.4 ng/ml and linearity was obtained from 14.8 to 475 ng/ml. The correlation coefficient between the ELISA and single radial immunodiffusion was 0.884. The ELISA was shown to be applicable to evaluate Hp concentrations in the lipoprotein fractions. Hp concentrations in the lipoprotein fractions were in the range of 0.94 to 8.77 microg of Hp/ml (n = 4), and concentration ratios were 0.2 to 0.3% of whole serum Hp. Of the lipoprotein fractions, Hp was most abundant in HDL, moderate in VHDL and faint in chylomicrons, the very low-density lipoprotein fraction and low-density lipoprotein fraction. By 2-dimensional electrophoresis, alpha- and beta-chains of serum Hp were each separated into 5 spots, and their isoelectric point (pI) values were from 5.05 to 6.28 in the alpha-chain and from 5.92 to 6.95 in the beta-chain. The pI values of HDL Hp were indistinguishable from those of serum Hp. These results indicate that the ELISA based on the affinity with Hb is useful for evaluating Hp concentrations in lipoprotein fractions, and also suggest that HDL Hp is structurally similar to that in the lipoprotein-deficient fraction.

Animals↗

In addition to the high-density lipoprotein fraction, apolipoprotein C-III is detected in chylomicrons and the very low-density lipoprotein fraction from serum of normolipidemic cows.

Apolipoprotein (apo) C-III is a low-molecular-mass protein that is involved in the regulation of the triglyceride metabolism. Except for the hyperlipidemic calf, cattle apoC-III is mainly detected in the high-density lipoprotein (HDL) fraction, and the distribution in chylomicrons (CM) and the very low-density lipoprotein (VLDL) fraction has not yet been clarified. The purpose of the present study was to detect apoC-III in concentrated CM and VLDL fractions to examine whether apoC-III is distributed in the two fractions even in normolipidemic cattle. ApoC-III could be detected by immunoblot analysis in both concentrated cow CM and VLDL fractions, but not in the corresponding calf fractions. These results suggest that apoC-III is distributed in the CM and VLDL fractions, at least in cows, although the concentrations in these fractions are considerably lower than in the HDL fraction.

Animals↗

Characteristics of cataracts in the Chinese Singaporean.

PURPOSE: To conduct an epidemiological survey of cataracts and examine the characteristics of lens opacities in Chinese Singaporeans. The results are then compared with those from two similar surveys previously done in Japan in Noto Area, Honshu, and Amami, Kyushu, respectively. SUBJECTS AND METHODS: 468 subjects of > or = 50 years of age, who responded to the invitation to participate, were examined. Examination principally included photo-documentation of the anterior and posterior segments of both eyes. Evaluation and grading of lens opacities were done using graphical analysis of Scheimpflug and retro-illumination images. Inter-group comparisons were based on statistical analysis of cataract prevalence and distribution. RESULTS: The prevalence of clear lenses decreased with aging with no significant difference between males and females--a finding common to Singapore and the two Japanese study groups. The prevalence of cataracts (or lens opacities of Grade II and above) in 60-79 year-old Singapore subjects was significantly higher than Noto and Amami subjects in the same age group. Further, cortical opacity was the main type in Singapore subjects in their 50s and which was significantly higher than Noto subjects of the same age group. In all age groups, the distribution and prevalence of both nuclear and subcapsular types in the Singapore group were higher than the two Japanese study groups. CONCLUSIONS: Cataracts in Chinese Singaporeans are characterized by a high prevalence of nuclear opacities which was generally seen in tropics and sub-tropics. Our study also suggested the involvement of solar-UV in cortical cataracts as well as that of additional risk factors, such as environmental temperature and race, in nuclear and subcapsular cataract formation.

Aged↗