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1.
Hepatology ; 59(1): 154-69, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23832448

RESUMO

UNLABELLED: Although nonalcoholic steatohepatitis (NASH) is associated with hypercholesterolemia, the underlying mechanisms of this association have not been clarified. We aimed to elucidate the precise role of cholesterol in the pathophysiology of NASH. C57BL/6 mice were fed a control, high-cholesterol (HC), methionine-choline-deficient (MCD), or MCD+HC diet for 12 weeks or a control, HC, high-fat (HF), or HF+HC diet for 24 weeks. Increased cholesterol intake accelerated liver fibrosis in both the mouse models without affecting the degree of hepatocellular injury or Kupffer cell activation. The major causes of the accelerated liver fibrosis involved free cholesterol (FC) accumulation in hepatic stellate cells (HSCs), which increased Toll-like receptor 4 protein (TLR4) levels through suppression of the endosomal-lysosomal degradation pathway of TLR4, and thereby sensitized the cells to transforming growth factor (TGF)ß-induced activation by down-regulating the expression of bone morphogenetic protein and activin membrane-bound inhibitor. Mammalian-cell cholesterol levels are regulated by way of a feedback mechanism mediated by sterol regulatory element-binding protein 2 (SREBP2), maintaining cellular cholesterol homeostasis. Nevertheless, HSCs were sensitive to FC accumulation because the high intracellular expression ratio of SREBP cleavage-activating protein (Scap) to insulin-induced gene (Insig) disrupted the SREBP2-mediated feedback regulation of cholesterol homeostasis in these cells. HSC activation subsequently enhanced the disruption of the feedback system by Insig-1 down-regulation. In addition, the suppression of peroxisome proliferator-activated receptor γ signaling accompanying HSC activation enhanced both SREBP2 and microRNA-33a signaling. Consequently, FC accumulation in HSCs increased and further sensitized these cells to TGFß-induced activation in a vicious cycle, leading to exaggerated liver fibrosis in NASH. CONCLUSION: These characteristic mechanisms of FC accumulation in HSCs are potential targets to treat liver fibrosis in liver diseases including NASH.


Assuntos
Colesterol/metabolismo , Fígado Gorduroso/complicações , Células Estreladas do Fígado/metabolismo , Cirrose Hepática/etiologia , Animais , Colesterol/administração & dosagem , Modelos Animais de Doenças , Regulação para Baixo , Fígado Gorduroso/metabolismo , Cirrose Hepática/metabolismo , Ativação de Macrófagos , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , PPAR gama/metabolismo , RNA Mensageiro/metabolismo , Receptores de LDL/metabolismo , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Regulação para Cima
2.
Hepatol Res ; 45(3): 349-55, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24739014

RESUMO

We present the case of a 25-year-old woman at 16 weeks of gestation who presented with non-comatose autoimmune acute liver failure and was at high risk of developing fulminant hepatitis. Predictive formulas indicated a high probability of developing fulminant hepatitis. Unenhanced computed tomography showed marked hepatic atrophy and broadly heterogeneous hypoattenuating areas. The course of her illness was subacute, and the etiology of liver injury was unclear. Considering all of the above, we predicted a poor prognosis. Plasma exchange (PE) and continuous hemodiafiltration (CHDF) therapy were initiated just after admission. A few days after admission, a high titer (×80) of antinuclear antibody was noted. Because autoimmune hepatitis (AIH) was considered a cause of liver failure, treatment with moderate prednisolone (30 mg/day) doses was administrated, with careful consideration of her pregnancy. Thereafter, her laboratory findings and clinical course gradually improved without the need for liver transplantation. A liver biopsy at 18 days after admission indicated a diagnosis of AIH. She continued the pregnancy and delivered a healthy baby without any complications. Eventually, prednisolone doses were decreased to 10 mg, after which her liver function worsened. The second liver biopsy also indicated a diagnosis of AIH. Accordingly, low-dose prednisolone and azathioprine doses (50 mg/day) were administrated to recover her liver function, after which her liver function regained normalcy. This case illustrates that a pregnant woman with non-comatose autoimmune acute liver failure in the first or second trimester of pregnancy and her fetus can be rescued by PE/CHDF therapy and safe moderate doses of prednisolone.

3.
J Hepatol ; 61(1): 98-106, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24657401

RESUMO

BACKGROUND & AIMS: Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes the conversion of free cholesterol (FC) to cholesterol ester, which prevents excess accumulation of FC. We recently found that FC accumulation in hepatic stellate cells (HSCs) plays a role in progression of liver fibrosis, but the effect of ACAT1 on liver fibrosis has not been clarified. In this study, we aimed to define the role of ACAT1 in the pathogenesis of liver fibrosis. METHODS: ACAT1-deficient and wild-type mice, or Toll-like receptor 4 (TLR4)(-/-)ACAT1(+/+) and TLR4(-/-)ACAT1(-/-) mice were subjected to bile duct ligation (BDL) for 3 weeks or were given carbon tetrachloride (CCl4) for 4 weeks to induce liver fibrosis. RESULTS: ACAT1 was the major isozyme in mice and human primary HSCs, and ACAT2 was the major isozyme in mouse primary hepatocytes and Kupffer cells. ACAT1 deficiency significantly exaggerated liver fibrosis in the mouse models of liver fibrosis, without affecting the degree of hepatocellular injury or liver inflammation, including hepatocyte apoptosis or Kupffer cell activation. ACAT1 deficiency significantly increased FC levels in HSCs, augmenting TLR4 protein and downregulating expression of transforming growth factor-ß (TGFß) pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor), leading to sensitization of HSCs to TGFß activation. Exacerbation of liver fibrosis by ACAT1 deficiency was dependent on FC accumulation-induced enhancement of TLR4 signaling. CONCLUSIONS: ACAT1 deficiency exaggerates liver fibrosis mainly through enhanced FC accumulation in HSCs. Regulation of ACAT1 activities in HSCs could be a target for treatment of liver fibrosis.


Assuntos
Colesterol/metabolismo , Células Estreladas do Fígado/metabolismo , Cirrose Hepática/metabolismo , Esterol O-Aciltransferase/metabolismo , Animais , Células Cultivadas , Ésteres do Colesterol/metabolismo , Progressão da Doença , Células Estreladas do Fígado/patologia , Humanos , Células de Kupffer/metabolismo , Células de Kupffer/patologia , Cirrose Hepática/etiologia , Cirrose Hepática/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Esterol O-Aciltransferase/deficiência , Esterol O-Aciltransferase/genética , Receptor 4 Toll-Like/deficiência , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Fator de Crescimento Transformador beta/metabolismo
4.
Gastroenterology ; 142(1): 152-164.e10, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21995947

RESUMO

BACKGROUND & AIMS: Some studies have indicated that dietary cholesterol has a role in the progression of liver fibrosis. We investigated the mechanisms by which dietary cholesterol might contribute to hepatic fibrogenesis. METHODS: C57BL/6 mice were fed a high-cholesterol diet or a control diet for 4 weeks; liver fibrosis then was induced by bile-duct ligation or carbon tetrachloride administration. Hepatic stellate cells (HSCs) were isolated from mice fed high-cholesterol diets or from Niemann-Pick type C1-deficient mice, which accumulate intracellular free cholesterol. RESULTS: After bile-duct ligation or carbon tetrachloride administration, mice fed high-cholesterol diets had significant increases in liver fibrosis and activation of HSCs compared with mice fed control diets. There were no significant differences in the degree of hepatocellular injury or liver inflammation, including hepatocyte apoptosis or Kupffer cell activation, between mice fed high-cholesterol or control diets. Levels of free cholesterol were much higher in HSCs from mice fed high-cholesterol diets than those fed control diets. In cultured HSCs, accumulation of free cholesterol in HSCs increased levels of Toll-like receptor 4 (TLR4), leading to down-regulation of bone morphogenetic protein and activin membrane-bound inhibitor (a pseudoreceptor for transforming growth factor [TGF]ß); the HSCs became sensitized to TGFß-induced activation. Liver fibrosis was not aggravated by the high-cholesterol diet in C3H/HeJ mice, which express a mutant form of TLR4; HSCs that express mutant TLR4 were not activated by accumulation of free cholesterol. CONCLUSIONS: Dietary cholesterol aggravates liver fibrosis because free cholesterol accumulates in HSCs, leading to increased TLR4 signaling, down-regulation of bone morphogenetic protein and activin membrane-bound inhibitor, and sensitization of HSC to TGFß. This pathway might be targeted by antifibrotic therapies.


Assuntos
Colesterol na Dieta/efeitos adversos , Células Estreladas do Fígado/metabolismo , Cirrose Hepática/etiologia , Animais , Apoptose , Ductos Biliares/cirurgia , Tetracloreto de Carbono , Colesterol na Dieta/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Células Estreladas do Fígado/patologia , Peptídeos e Proteínas de Sinalização Intracelular , Células de Kupffer/metabolismo , Ligadura , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína C1 de Niemann-Pick , Doença de Niemann-Pick Tipo C/genética , Doença de Niemann-Pick Tipo C/metabolismo , Proteínas/genética , Proteínas/metabolismo , Transdução de Sinais , Fatores de Tempo , Receptor 4 Toll-Like/metabolismo , Fator de Crescimento Transformador beta/metabolismo
5.
Langmuir ; 29(3): 857-60, 2013 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-23270307

RESUMO

In this report, we present a novel approach for the elucidation of the physicochemical properties of lipid membranes by isothermal titration calorimetry (ITC) to quantify the heat absorbed during the solubilization of vesicles into TritonX-100 micelles. By using large and small unilamellar vesicles for comparison, this method provides calorimetric data on the gel-to-liquid-crystalline phase transition and its curvature effects and, in particular, the enthalpy change upon membrane deformation from a planar to a curved shape, which cannot be obtained by the conventional approach using differential scanning calorimetry. The results showed quantitatively that the increase in membrane curvature increases the enthalpy of 1,2-dimyristoyl-sn-glycero-3-phosphocholine membranes both below and above the phase-transition temperature, and that the effect is more significant for the former condition. The calorimetric data obtained are further discussed in relation to the elastic bending energy of the membranes and membrane-peptide interaction.


Assuntos
Calorimetria , Dimiristoilfosfatidilcolina/análogos & derivados , Lipídeos/química , Lipossomas Unilamelares/química , Dimiristoilfosfatidilcolina/química , Micelas , Octoxinol/química , Solubilidade
6.
Glob Health Med ; 5(2): 70-74, 2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37128229

RESUMO

Japan's responses to COVID-19 have been conducted based on the Act on the Prevention of Infectious Diseases and Medical Care for Patients with Infectious Diseases (the Infectious Diseases Control Law) and the Act on Special Measures against Novel Influenza, etc. (the Act on Special Measures), as COVID-19 is classified as the category of "the Novel Influenza etc." under the Infectious Diseases Control Law. The government's Novel Coronavirus Response Headquarters decided to reclassify COVID-19 as a Category V infectious disease under the Infectious Diseases Control Law in May 2023 since the disease has become less lethal. Accordingly, the countermeasures such as surveillance and medical care are going to be reviewed, and COVID-19 prevention actions will depend on personal choices (Prior to the review in May, mask usage will be changed from 13 March). However, this does not mean that infection control measures are no longer necessary; it is recommended that such measures be taken in certain settings in order to prevent the elderly and those who at a high risk of severe illness from being infected, even after the disease is classified as Category V.

7.
J Hepatol ; 57(4): 837-43, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22641095

RESUMO

BACKGROUND & AIMS: The tumor suppressor p53 is a primary sensor of stressful stimuli, controlling a number of biologic processes. The aim of our study was to examine the roles of p53 in non-alcoholic steatohepatitis (NASH). METHODS: Male wild type and p53-deficient mice were fed a methionine- and choline-deficient diet for 8 weeks to induce nutritional steatohepatitis. mRNA expression profiles in normal liver samples and liver samples from patients with non-alcoholic liver disease (NAFLD) were also evaluated. RESULTS: Hepatic p53 and p66Shc signaling was enhanced in the mouse NASH model. p53 deficiency suppressed the enhanced p66Shc signaling, decreased hepatic lipid peroxidation and the number of apoptotic hepatocytes, and ameliorated progression of nutritional steatohepatitis. In primary cultured hepatocytes, transforming growth factor (TGF)-ß treatment increased p53 and p66Shc signaling, leading to exaggerated reactive oxygen species (ROS) accumulation and apoptosis. Deficient p53 signaling inhibited TGF-ß-induced p66Shc signaling, ROS accumulation, and hepatocyte apoptosis. Furthermore, expression levels of p53, p21, and p66Shc were significantly elevated in human NAFLD liver samples, compared with results obtained with normal liver samples. Among NAFLD patients, those with NASH had significantly higher hepatic expression levels of p53, p21, and p66Shc compared with the group with simple steatosis. A significant correlation between expression levels of p53 and p66Shc was observed. CONCLUSIONS: p53 in hepatocytes regulates steatohepatitis progression by controlling p66Shc signaling, ROS levels, and apoptosis, all of which may be regulated by TGF-ß. Moreover, p53/p66Shc signaling in the liver appears to be a promising target for the treatment of NASH.


Assuntos
Fígado Gorduroso/metabolismo , RNA Mensageiro/metabolismo , Proteínas Adaptadoras da Sinalização Shc/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Deficiência de Colina/complicações , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Fígado Gorduroso/etiologia , Fígado Gorduroso/patologia , Hepatócitos/metabolismo , Humanos , Masculino , Metionina/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica , Cultura Primária de Células , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Proteína Supressora de Tumor p53/genética , Regulação para Cima/efeitos dos fármacos
8.
Vaccines (Basel) ; 10(9)2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36146539

RESUMO

The mRNA-1273 Moderna COVID-19 vaccine was introduced to combat the COVID-19 global pandemic in 2020. Although the safety of the vaccine has been investigated worldwide, real-world safety data is scarce in Japan. An online, real-time survey of adverse events following immunization (AEFIs) with mRNA-1273 was conducted in the setting of a workplace vaccination program at the School of Pharmacy, Keio University from 26 June 2021, to 11 June 2022. Participants were requested to take four surveys during a seven-day follow-up period after each of the first, second, and third booster doses. The maximum number of responses, from 301 respondents, was obtained on day 0 (vaccination date) for the first dose. 98% of respondents reported local and systemic AEFIs for the second dose on day 1. No noticeable difference in local reactions was seen among the three doses. Females reported more AEFIs than males, and the young group (18-29 years) reported a higher rate than the middle age group (≥30 years) after the first dose. Age and gender differences in rates decreased at the second and third doses. This survey confirmed that the safety profile of mRNA-1273 in a real-world setting was similar to that derived from the clinical trials, and that the agent was well-tolerated.

9.
Dig Dis Sci ; 56(10): 3045-52, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21516322

RESUMO

BACKGROUND/AIMS: Serum free fatty acid (FFA) composition and abnormal fatty acid metabolism have been implicated in the pathogenesis of nonalcoholic steatohepatitis (NASH). Therefore, we determined if the serum FFA composition can provide accurate diagnosis of NASH. METHODS: We compared fasting serum FFA compositions in 20 patients with simple steatosis to those in 77 patients with NASH, including 65 patients with early-stage NASH. RESULTS: By univariate analysis, the proportions of serum free myristic acid (P = 0.002) and palmitoleic acid (P = 0.033) and the stearoyl CoA desaturase (SCD)-1 index (P = 0.047) were significantly elevated in NASH patients in comparison to patients with simple steatosis. Only the serum free myristic acid proportion was significantly elevated in the early-stage NASH group in comparison to the simple steatosis group (P = 0.003). Multiple logistic regression analysis demonstrated that the serum free myristic acid proportion was significantly elevated in all patients with NASH (P = 0.011) and the subset of patients with early-stage NASH (P = 0.012) in comparison to those with simple steatosis. The area under the curve (AUC) for the serum free myristic acid proportion was 0.734 to detect NASH and 0.719 to detect early-stage NASH in comparison to simple steatosis. CONCLUSIONS: Serum free myristic acid proportion could be a useful independent predictor to differentiate NASH from simple steatosis.


Assuntos
Fígado Gorduroso/sangue , Fígado Gorduroso/diagnóstico , Ácido Mirístico/sangue , Adulto , Biomarcadores/sangue , Diagnóstico Diferencial , Ácidos Graxos não Esterificados/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica , Valor Preditivo dos Testes , Análise de Regressão , Estudos Retrospectivos
10.
Dig Dis Sci ; 56(12): 3648-54, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21674175

RESUMO

BACKGROUND AND AIMS: The similarity of alcoholic liver disease and nonalcoholic steatohepatitis (NASH) in terms of pathogenic mechanisms suggests that immunoglobulin A (IgA) may play an important role in the pathogenesis of NASH. We aimed to determine whether serum IgA concentrations allow a diagnosis of liver fibrosis in NASH. METHODS: We compared serum IgA concentrations between 108 patients with stages 0-2 NASH and 19 patients with stage 3 NASH. RESULTS: In a univariate analysis, age (P < 0.0001), gender (P = 0.0039), serum albumin level (P = 0.0192), AST (P < 0.0001), AST/ALT ratio (P < 0.0001), platelet count (P = 0.0027), hyaluronic acid level (P < 0.0001), fasting blood sugar (FBS) (P = 0.0013), IRI (P = 0.0001), prothrombin time (%) (P = 0.0287), IgA (P < 0.0001), total sum of IgG, IgA, and IgM (P = 0.0049), and IgA/(IgG + IgA + IgM) (P = 0.0105) were significantly elevated in severe-stage NASH patients compared with the early-stage NASH group. Multiple logistic regression analysis showed that in severe-stage NASH patients, only serum IgA concentrations were significantly elevated (P = 0.0225) relative to early-stage NASH patients. The area under the curve (AUC) of serum IgA concentrations was 0.758 for detecting severe-stage NASH compared with early-stage NASH. CONCLUSIONS: Serum IgA concentration could be a useful independent predictor for assessing the pre-cirrhotic progression of NASH.


Assuntos
Fígado Gorduroso/sangue , Imunoglobulina A/sangue , Cirrose Hepática/sangue , Adulto , Biomarcadores/sangue , Biópsia , Diagnóstico Diferencial , Progressão da Doença , Fígado Gorduroso/complicações , Fígado Gorduroso/diagnóstico , Feminino , Seguimentos , Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/etiologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença
11.
Intern Med ; 60(16): 2569-2575, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34148952

RESUMO

Objective To consider effective measures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in medical institutions, this study estimated the SARS-CoV-2 infection rate among healthcare workers (HCWs) in Tokyo, Japan, and determined the specific findings for mild coronavirus disease 2019 (COVID-19) cases. Methods This study analyzed the results of serologic tests to detect immunoglobulin G antibodies against SARS-CoV-2 and evaluated the demographic and clinical characteristics of the faculty and HCWs at a Tokyo medical institution in August 2020. The demographic and clinical characteristics of participants with antibody-positive results were compared to those of participants with antibody-negative results. Materials This study recruited 2,341 faculty and HCWs at a Tokyo medical institution, 21 of whom had a COVID-19 history. Results Of the 2,320 participants without a COVID-19 history, 20 (0.862%) had positive serologic test results. A fever and dysgeusia or dysosmia occurred with greater frequency among the participants with positive test results than in those with negative results [odds ratio (OR), 5.475; 95% confidence interval (CI), 1.960-15.293 and OR, 24.158; 95% CI, 2.693-216.720, respectively]. No significant difference was observed in the positivity rate between HCWs providing medical care for COVID-19 patients using adequate protection and other HCWs (OR, 2.514; 95% CI, 0.959-6.588). Conclusion To reduce the risk of COVID-19 spread in medical institutions, faculty and HCWs should follow standard and necessary transmission-based precautions, and those with a fever and dysgeusia or dysosmia should excuse themselves from work as soon as possible.


Assuntos
COVID-19 , SARS-CoV-2 , Docentes , Pessoal de Saúde , Humanos , Japão/epidemiologia , Tóquio/epidemiologia
12.
Microcirculation ; 17(5): 321-32, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20618690

RESUMO

OBJECTIVE: Aberrant leukocyte migration has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Lemon grass is a natural herb that contains citral, which suppresses lymphocyte expression of gut homing molecules by inhibiting retinoic acid formation. We therefore hypothesized that lemon grass intake could ameliorate excess migration of leukocytes to the inflamed intestine in chronic ileitis. METHODS: Migration of fluorescence-labeled T cells to microvessels in the ileal mucosa of SAMP1/Yit mice was monitored using intravital microscopy. In some mice, lemon grass solution was administered for two weeks. For evaluation of the effects on chronic ileitis, mice were treated with lemon grass for 26 weeks. RESULTS: Surface expression of beta7 and CCR9 on T lymphocytes was stronger in SAMP1/Yit mice than in AKR/J mice. Lemon grass treatment attenuated the surface expression of beta7-integrin and CCR9. The number of adherent lymphocytes to microvessels in chronic inflamed ileum was significantly few when lymphocytes were isolated from lemon grass treated mice. Long-term lemon grass treatment improved ileitis in SAMP1/Yit mice, which was assessed by body weight, histological changes and the infiltration of beta7-positive cells. CONCLUSION: Lemon grass ameliorated ileitis through decreasing lymphocyte migration by inhibiting beta7-expression, suggesting its therapeutic usefulness for IBD.


Assuntos
Cymbopogon , Ileíte/tratamento farmacológico , Fitoterapia , Linfócitos T/efeitos dos fármacos , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Animais , Movimento Celular/efeitos dos fármacos , Ileíte/imunologia , Ileíte/patologia , Íleo/irrigação sanguínea , Íleo/efeitos dos fármacos , Íleo/patologia , Cadeias beta de Integrinas/metabolismo , Mucosa Intestinal/irrigação sanguínea , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos AKR , Microscopia de Fluorescência , Microvasos/efeitos dos fármacos , Microvasos/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores CCR/metabolismo , Linfócitos T/patologia , Linfócitos T/fisiologia , Tretinoína/metabolismo
13.
Alcohol Clin Exp Res ; 34 Suppl 1: S39-44, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19824993

RESUMO

BACKGROUND: We previously reported that an NAD-dependent in situ retinoic acid supply system, which comprises some isoforms of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) and provides retinoic acid from retinol via a 2-step oxidation process, exists in the rat esophagus. Herein, their isoforms responsible for the pathway and its localization in the rat esophagus was examined. METHODS: The expressions of mRNAs of various isoforms of ADH and ALDH were examined in the fraction mainly comprising mucosal layer of the rat esophagus by RT-PCR. Expression levels of Class IV ADH and ALDH 1A1 were compared between the fractions and that mainly comprising muscle layer of the rat esophagus by quantitative PCR. The catalytic activities producing retinoic acid from retinal were compared between the 2 fractions and its optimum pH was also determined. RESULTS: Classes I, III, and IV ADHs and ALDHs 1A1 and 3A1 were predominant isoforms in the rat esophageal mucosa. The expression levels of mRNA of Class IV ADH and ALDH 3A1 were significantly higher in the mucosal than in the muscle layer. Consistently, the catalytic activities producing retinoic acid from retinal were significantly higher in the former than the latter. The optimum pH of the process was 9.0. CONCLUSIONS: Considering the affinities for retinol and retinal of ADHs and ALDHs expressed in the rat esophagus, the NAD-dependent in situ retinoic acid supply system in the rat esophagus is thought to comprise Class IV ADH and ALDH 1A1. In the rat esophagus, the system exists predominantly in the mucosal layer.


Assuntos
Álcool Desidrogenase/análise , Aldeído Desidrogenase/análise , Esôfago/enzimologia , Isoenzimas/análise , NAD/farmacologia , Tretinoína/metabolismo , Álcool Desidrogenase/genética , Álcool Desidrogenase/metabolismo , Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo , Animais , Expressão Gênica , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Mucosa/enzimologia , Músculo Liso/enzimologia , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Ratos , Ratos Wistar
14.
Open Forum Infect Dis ; 7(12): ofaa512, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33330740

RESUMO

BACKGROUND: Nosocomial spread of coronavirus disease 2019 (COVID-19) causes clusters of infection among high-risk individuals. Controlling this spread is critical to reducing COVID-19 morbidity and mortality. We describe an outbreak of COVID-19 in Keio University Hospital, Japan, and its control and propose effective control measures. METHODS: When an outbreak was suspected, immediate isolation and thorough polymerase chain reaction (PCR) testing of patients and health care workers (HCWs) using an in-house system, together with extensive contact tracing and social distancing measures, were conducted. Nosocomial infections (NIs) were defined as having an onset or positive test after the fifth day of admission for patients and having high-risk contacts in our hospital for HCWs. We performed descriptive analyses for this outbreak. RESULTS: Between March 24 and April 24, 2020, 27 of 562 tested patients were confirmed positive, of whom 5 (18.5%) were suspected as NIs. For HCWs, 52 of 697 tested positive, and 40 (76.9%) were considered NIs. Among transmissions, 95.5% were suspected of having occurred during the asymptomatic period. Large-scale isolation and testing at the first sign of outbreak terminated NIs. The number of secondary cases directly generated by a single primary case found before March 31 was 1.74, compared with 0 after April 1. Only 4 of 28 primary cases generated definite secondary infection; these were all asymptomatic. CONCLUSIONS: Viral shedding from asymptomatic cases played a major role in NIs. PCR screening of asymptomatic individuals helped clarify the pattern of spread. Immediate large-scale isolation, contact tracing, and social distancing measures were essential to containing outbreaks.

15.
Hepatology ; 48(2): 458-73, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18666257

RESUMO

UNLABELLED: It is unclear how hepatic adiponectin resistance and sensitivity mediated by the adiponectin receptor, AdipoR2, contributes to the progression of nonalcoholic steatohepatitis (NASH). The aim of this study was to examine the roles of hepatic AdipoR2 in NASH, using an animal model. We fed C57BL/6 mice a methionine-deficient and choline-deficient (MCD) diet for up to 8 weeks and analyzed changes in liver pathology caused by either an AdipoR2 short hairpin RNA-expressing adenovirus or an AdipoR2-overexpressing adenovirus. Inhibition of hepatic AdipoR2 expression aggravated the pathological state of NASH at all stages: fatty changes, inflammation, and fibrosis. In contrast, enhancement of AdipoR2 expression in the liver improved NASH at every stage, from the early stage to the progression of fibrosis. Inhibition of AdipoR2 signaling in the liver diminished hepatic peroxisome proliferator activated receptor (PPAR)-alpha signaling, with decreased expression of acyl-CoA oxidase (ACO) and catalase, leading to an increase in lipid peroxidation. Hepatic AdipoR2 overexpression had the opposite effect. Reactive oxygen species (ROS) accumulation in liver increases hepatic production of transforming growth factor (TGF)-beta1 at all stages of NASH; adiponectin/AdipoR2 signaling ameliorated TGF-beta-induced ROS accumulation in primary cultured hepatocytes, by enhancing PPAR-alpha activity and catalase expression. CONCLUSION: The adiponectin resistance and sensitivity mediated by AdipoR2 in hepatocytes regulated steatohepatitis progression by changing PPAR-alpha activity and ROS accumulation, a process in which TGF-beta signaling is implicated. Thus, the liver AdipoR2 signaling pathway could be a promising target in treating NASH.


Assuntos
Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Fígado/metabolismo , Receptores de Adiponectina/metabolismo , Transdução de Sinais , Animais , Catalase/metabolismo , Células Cultivadas , Deficiência de Colina/complicações , Dieta , Progressão da Doença , Ativação Enzimática , Fígado Gorduroso/etiologia , Técnicas de Transferência de Genes , Hepatócitos/metabolismo , Masculino , Metionina/deficiência , Camundongos , Camundongos Endogâmicos C57BL , PPAR alfa/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
16.
Scand J Gastroenterol ; 44(2): 229-36, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18819037

RESUMO

OBJECTIVE: In patients with non-alcoholic fatty liver disease (NAFLD), liver biopsy remains the only reliable method to differentiate simple steatosis from non-alcoholic steatohepatitis (NASH). The objective of this study was to evaluate the efficacy of non-invasive (99m)Tc-phytate scintigraphy in the diagnosis of NASH. MATERIAL AND METHODS: Thirty-seven patients with suspected NAFLD at the time of liver biopsy also underwent (99m)Tc-phytate scintigraphy. Signal intensities of regions of interest (ROI) in the liver, spleen, and heart were measured. We also examined scintigraphic features in a nutritional model of NASH in rats fed a methionine- and choline-deficient (MCD) diet. RESULTS: The liver/spleen uptake ratio determined by scintigraphy was significantly decreased in patients with NASH in comparison with patients with simple steatosis. The liver/spleen ratio was an independent predictor distinguishing NASH from simple steatosis. The decrease was observed for all stages of NASH, including the early stage (stages 1 and 0). In animal studies, the liver/spleen uptake ratio was significantly decreased in rats after 8 weeks of MCD dietary feeding in comparison with control diet-fed rats. CONCLUSIONS: The non-invasive (99m)Tc-phytate scintigraphy test is a reliable tool to differentiate NASH from simple steatosis.


Assuntos
Fígado Gorduroso/diagnóstico por imagem , Fígado/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tecnécio , Adulto , Animais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Cintilografia , Ratos , Ratos Wistar , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
17.
Med Sci Monit ; 15(6): PH57-64, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19478713

RESUMO

BACKGROUND: Hypertension, hyperlipidemia, and hyperglycemia often occur in drinkers regardless of obesity. Thus, the diagnostic criteria of metabolic syndrome (MS) may judge some drinkers as having MS even when typical MS is absent. MATERIAL/METHODS: To verify this, 1,346 Japanese men aged 40 to 65 were divided into four groups based on their statuses of MS and drinking habits, and various parameters were compared among them. According to the suggestion of the Japanese Ministry of Health, Labour and Welfare, daily ethanol consumption up to 20 grams was defined as safe drinking. RESULTS: The serum adiponectin level was significantly higher in unsafe drinkers with MS than in those without it, whereas drinking habits were shown not to affect it. Among subjects judged to have MS, the ALT/AST ratio (ALT/AST) was the most effective parameter to distinguish between safe and unsafe drinkers. When unsafe drinkers with MS were classified into two subgroups by ALT/AST, i.e. that of > or =0.9 or <0.9, levels of ALT and adiponectin significantly differed between them and levels in the former and the latter subgroups were comparable to those in safe drinkers with MS and in unsafe drinkers without MS, respectively. Although the prevalence of MS was higher in unsafe drinkers than in safe drinkers, it became equivalent to each other when the latter subgroup was eliminated. CONCLUSIONS: In drinkers who satisfy the diagnostic criteria of MS, subjects whose characteristics are different from those of typical MS, but comparable to those of alcohol-related syndrome, co-exist. This over-diagnosis is most likely due to ethanol consumption.


Assuntos
Consumo de Bebidas Alcoólicas/patologia , Síndrome Metabólica/patologia , Segurança , Adiponectina/metabolismo , Adulto , Idoso , Alanina Transaminase/metabolismo , Aspartato Aminotransferases/metabolismo , Humanos , Masculino , Síndrome Metabólica/enzimologia , Pessoa de Meia-Idade
18.
J Orthop Surg (Hong Kong) ; 27(3): 2309499019874470, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31549573

RESUMO

PURPOSE: The purpose of this study was to evaluate local and systemic pathology in a murine model of ischemia-reperfusion (I/R) injury induced by long-term application of a tourniquet on the hind limbs and to assess the protective effects of edaravone, a potent systemic scavenger of free radicals, using this model. METHODS: Sixty C57BL6 mice were divided in two groups, with one group receiving a 3 mg/kg intraperitoneal injection of edaravone and the other group receiving an identical amount of saline 30 min before ischemia under deep anesthesia. The left thigh of each animal was constricted for 4 h with a 4.5-oz. orthodontic rubber band to induce ischemia; 4 h was the critical duration for skeletal muscles. After ischemia, specimens of skeletal muscles, both kidneys, and plasma were collected at 0, 2, 12, 24, 48, and 72 h. Injury to the skeletal muscles and vacuolar degeneration of the kidneys were histologically assessed. Additionally, apoptosis of skeletal muscle cells was assessed by analysis of caspase 3/7 activity and TUNEL staining. Plasma tumor necrosis factor (TNF)-α levels were measured using an enzyme-linked immunosorbent assay kit. RESULTS: Skeletal muscles exhibited prominent injury of myofibers at 12 h after I/R injury, with clear upregulation of plasma TNF-α expression and histologic evidence of tubular dysfunction of the kidneys. Plasma TNF-α levels declined and histologic renal damage was ameliorated in edaravone-treated mice, but treatment did not protect skeletal muscle following ischemia for 4 h. Nonetheless, compared with group S, expression of the apoptosis marker caspase 3/7 was significantly inhibited in the skeletal hind limb muscles of Ed-group mice affected by reperfusion injury following ischemia for 4 h. CONCLUSION: The present study demonstrated that edaravone is a potentially useful drug for systemic or local treatment of reperfusion injury resulting from long-term ischemia.


Assuntos
Edaravone/farmacologia , Membro Posterior/irrigação sanguínea , Inflamação/tratamento farmacológico , Músculo Esquelético/patologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , Sequestradores de Radicais Livres/farmacologia , Membro Posterior/fisiopatologia , Inflamação/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão/complicações , Torniquetes
19.
Cell Physiol Biochem ; 21(4): 269-78, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18441515

RESUMO

In this study, we demonstrate that a putative membrane unknown solute transporter 1 of the rat kidney (UST1r; Slc22a9) is a multispecific transporter of organic anions (OAs). When expressed in Xenopus oocytes, UST1r mediated uptake of ochratoxin A (OTA; K(m) = 1.0 microM) and sulfate conjugates of steroids, such as estrone-3-sulfate (ES; K(m) = 3.1 microM) and dehydroepiandrosterone sulfate (DHEAS; K(m) = 2.1 microM) in a sodium-independent manner. We herein propose that UST1r be renamed OA transporter 8 (rOat8). rOat8 interacted with chemically heterogenous anionic compounds, such as nonsteroidal anti-inflammatory drugs, diuretics, probenecid, taurocholate, and methotrexate, but not with the organic cation tetraethylammonium. The rOat8-mediated ES transport was: a) cis-inhibited by 4-methylumbelliferyl sulfate and beta-estradiol sulfate, but not by glucuronide conjugates of these compounds, b) cis-inhibited by four- and five- carbon (C4/C5) dicarboxylates (succinate and glutarate (GA)), and c) trans-stimulated by GA, whereas the efflux of GA was significantly trans-stimulated by ES. By RT-PCR, rOat8 mRNA was expressed in proximal convoluted tubules and cortical and outer medullary collecting ducts, whereas in immunochemical studies, Oat8 was identified as the ñ58 kDa protein that in the collecting duct colocalized with the V-ATPase in plasma membranes and intracellular vesicles in various subtypes of intercalated cells. Molecular identification of Oat8 in these cells indicates a possible novel role of OAT family in the renal secretion/reabsorption of OA and acids and bases via affecting the V-ATPase-dependent functions.


Assuntos
Túbulos Renais Coletores/imunologia , Túbulos Renais Coletores/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Animais , Transporte Biológico , Feminino , Imuno-Histoquímica , Masculino , Oócitos , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Ratos , Ratos Wistar , Xenopus laevis
20.
J Oleo Sci ; 67(1): 67-75, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29311523

RESUMO

It has been reported that a lot of receptors localize in lipid raft domains and that the microfluidity of these domains regulates the activation of these receptors. In this study, we focused on the lipid raft and in order to evaluate the physicochemical effects of surfactants on microfluidity of lipid membranes, we used liposomes comprising of egg-yolk L-α-phosphatidylcholine, egg-yolk sphingomyelin, and cholesterol as a model of cell membranes containing raft domains. The microfluidity of the domains was characterized by fluorescence spectrometry using 1,6-diphenyl-1,3,5-hexatriene and 2-dimethylamino-6-lauroylnaphthalene. Among several surfactants, dialkylammonium-type cationic surfactants most efficiently increased the microfluidity. It is therefore concluded that (1) the electrostatic interaction between the cationic surfactant and eggPC/eggSM/cholesterol liposome could be important, (2) surfactants with alkyl chains more effectively inserted into membranes than those with acyl chains, and (3) cationic surfactants with lower Tm values have a greater ability to increase the fluidity.


Assuntos
Compostos de Amônio , Membrana Celular , Fluidez de Membrana , Lipídeos de Membrana , Microdomínios da Membrana , Tensoativos , Cátions , Fenômenos Químicos , Colesterol , Gema de Ovo , Lipossomos , Fosfatidilcolinas , Espectrometria de Fluorescência , Esfingomielinas , Eletricidade Estática , Tensoativos/química
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