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1.
FASEB J ; 36(12): e22645, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36349991

RESUMO

Melanocortin-4 receptor (MC4R) is a critical regulator of appetite and energy expenditure in rodents and humans. MC4R deficiency causes hyperphagia, reduced energy expenditure, and impaired glucose metabolism. Ligand binding to MC4R activates adenylyl cyclase, resulting in increased levels of intracellular cyclic adenosine monophosphate (cAMP), a secondary messenger that regulates several cellular processes. Cyclic adenosine monophosphate responsive element-binding protein-1-regulated transcription coactivator-1 (CRTC1) is a cytoplasmic coactivator that translocates to the nucleus in response to cAMP and is reportedly involved in obesity. However, the precise mechanism through which CRTC1 regulates energy metabolism remains unknown. Additionally, there are no reports linking CRTC1 and MC4R, although both CRTC1 and MC4R are known to be involved in obesity. Here, we demonstrate that mice lacking CRTC1, specifically in MC4R cells, are sensitive to high-fat diet (HFD)-induced obesity and exhibit hyperphagia and increased body weight gain. Moreover, the loss of CRTC1 in MC4R cells impairs glucose metabolism. MC4R-expressing cell-specific CRTC1 knockout mice did not show changes in body weight gain, food intake, or glucose metabolism when fed a normal-chow diet. Thus, CRTC1 expression in MC4R cells is required for metabolic adaptation to HFD with respect to appetite regulation. Our results revealed an important protective role of CRTC1 in MC4R cells against dietary adaptation.


Assuntos
Resistência à Insulina , Receptor Tipo 4 de Melanocortina , Humanos , Camundongos , Animais , Receptor Tipo 4 de Melanocortina/genética , Receptor Tipo 4 de Melanocortina/metabolismo , Hiperfagia/genética , Hiperfagia/metabolismo , Obesidade/genética , Obesidade/metabolismo , Metabolismo Energético , Camundongos Knockout , Fatores de Transcrição/metabolismo , Glucose , Monofosfato de Adenosina/metabolismo
2.
Kyobu Geka ; 76(8): 608-612, 2023 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-37500548

RESUMO

An 82-year-old female patient with severe aortic stenosis underwent aortic valve replacement. After weaning from cardiopulmonary bypass, it was noticed that Swan-Ganz( SG) catheter tip was located 50 cm distally to the right neck. After the catheter was pulled back, massive hemoptysis occurred. Fiberoptic bronchoscopy revealed bleeding from the left main bronchus. The tracheal tube was exchanged to a left selective bronchial tube and protamine sulfate was administered. However, massive hemorrhage continued. Intraoperative selective pulmonary angiography identified a pseudoaneurysm in A10. Efferent arteries, A10a, A10b, A10c, and an afferent artery, A10, were successfully embolized to obtain hemostasis. The patient remained hypoxemic despite inhalation with 100% oxygen and high positive end-expiratory pressure, so veno-arterial extracorporeal membrance oxygenation (VA-ECMO) was initiated. The patient was then transferred to intensive care unit (ICU) with VA-ECMO and the sternum was left open. Strenuous bronchial lavage was performed and VA-ECMO was discontinued at 2 days later. The patient was weaned from ventilator 14 days and discharged 63 days postoperatively.


Assuntos
Falso Aneurisma , Artéria Pulmonar , Feminino , Humanos , Idoso de 80 Anos ou mais , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/cirurgia , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/etiologia , Falso Aneurisma/cirurgia , Hemorragia , Catéteres
3.
Am J Physiol Endocrinol Metab ; 322(5): E436-E445, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35344393

RESUMO

The melanocortin 4 receptor (MC4R) plays an important role in the regulation of appetite and energy expenditure in humans and rodents. Impairment of MC4R signaling causes severe obesity. MC4R mainly couples to the G-protein Gs. Ligand binding to MC4R activates adenylyl cyclase resulting in increased intracellular cAMP levels. cAMP acts as a secondary messenger, regulating various cellular processes. MC4R can also couple with Gq and other signaling pathways. Therefore, the contribution of MC4R/Gs signaling to energy metabolism and appetite remains unclear. To study the effect of Gs signaling activation in MC4R cells on whole body energy metabolism and appetite, we generated a novel mouse strain that expresses a Gs-coupled designer receptors exclusively activated by designer drugs [Gs-DREADD (GsD)] selectively in MC4R-expressing cells (GsD-MC4R mice). Chemogenetic activation of the GsD by a designer drug [deschloroclozapine (DCZ); 0.01∼0.1 mg/kg body wt] in MC4R-expressing cells significantly increased oxygen consumption and locomotor activity. In addition, GsD activation significantly reduced the respiratory exchange ratio, promoting fatty acid oxidation, but did not affect core (rectal) temperature. A low dose of DCZ (0.01 mg/kg body wt) did not suppress food intake, but a high dose of DCZ (0.1 mg/kg body wt) suppressed food intake in MC4R-GsD mice, although either DCZ dose (0.01 or 0.1 mg/kg body wt) did not affect food intake in the control mice. In conclusion, the current study demonstrated that the stimulation of Gs signaling in MC4R-expressing cells increases energy expenditure and locomotor activity and suppresses appetite.NEW & NOTEWORTHY We report that Gs signaling in melanocortin 4 receptor (MC4R)-expressing cells regulates energy expenditure, appetite, and locomotor activity. These findings shed light on the mechanism underlying the regulation of energy metabolism and locomotor activity by MC4R/cAMP signaling.


Assuntos
Proteínas de Ligação ao GTP , Obesidade , Receptor Tipo 4 de Melanocortina , Animais , Ingestão de Alimentos , Metabolismo Energético , Proteínas de Ligação ao GTP/metabolismo , Locomoção , Camundongos , Obesidade/metabolismo , Receptor Tipo 4 de Melanocortina/genética
4.
J Am Chem Soc ; 143(30): 11325-11331, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34283597

RESUMO

Photoinduced in situ "oxidation" of half-sandwich metal complexes to "high-valent" cationic metal complexes has been used to accelerate catalytic reactions. Here, we report the unprecedented photoinduced in situ "reduction" of half-sandwich metal [Rh(III)] complexes to "low-valent" anionic metal [Rh(II)] ate complexes, which facilitate ligand exchange with electron-deficient elements (diboron). This strategy was realized by using a functionalized cyclopentadienyl (CpA3) Rh(III) catalyst we developed, which enabled the basic group-directed room temperature ortho-C-H borylation of arenes.

5.
Chemistry ; 26(26): 5774-5779, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31950561

RESUMO

It has been established that a newly developed cyclopentadienyl rhodium(III) [CpA RhIII ] complex, bearing an acidic secondary amide moiety on the Cp ring, is able to catalyze the ortho-bromination of O-phenyl carbamates with N-bromosuccinimide (NBS) at room temperature. The presence of the acidic secondary amide moiety on the CpA ligand accelerates the bromination by the hydrogen bond between the acidic NH group of the CpA ligand and the carbonyl group of NBS.

6.
Int J Legal Med ; 132(4): 975-981, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28803416

RESUMO

Screening for male-derived biological material from collected samples plays an important role in criminal investigations, especially those involving sexual assaults. We have developed a loop-mediated isothermal amplification (LAMP) assay targeting multi-repeat sequences of the Y chromosome for detecting male DNA. Successful amplification occurred with 0.5 ng of male DNA under isothermal conditions of 61 to 67 °C, but no amplification occurred with up to 10 ng of female DNA. Under the optimized conditions, the LAMP reaction initiated amplification within 10 min and amplified for 20 min. The LAMP reaction was sensitive at levels as low as 1-pg male DNA, and a quantitative LAMP assay could be developed because of the strong correlation between the reaction time and the amount of template DNA in the range of 10 pg to 10 ng. Furthermore, to apply the LAMP assay to on-site screening for male-derived samples, we evaluated a protocol using a simple DNA extraction method and a colorimetric intercalating dye that allows detection of the LAMP reaction by evaluating the change in color of the solution. Using this protocol, samples of male-derived blood and saliva stains were processed in approximately 30 min from DNA extraction to detection. Because our protocol does not require much hands-on time or special equipment, this LAMP assay promises to become a rapid and simple screening method for male-derived samples in forensic investigations.


Assuntos
Cromossomos Humanos Y , DNA/análise , Genética Forense/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Análise para Determinação do Sexo/métodos , Colorimetria , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Saliva/química
7.
MicroPubl Biol ; 20242024.
Artigo em Inglês | MEDLINE | ID: mdl-38725940

RESUMO

DNA typing based on short tandem repeat (STR) analysis is an effective forensic method for human identification. Some STRs are contained within the introns of protein-coding genes and are transcribed as pre-mRNAs. However, the possibility of using RNA for STR analysis is yet to be fully explored. Considering that RNA in forensic samples is relatively stable, especially under dry- and low-temperature conditions, we hypothesized that STR information could be obtained from RNA. Here, we investigated the possibility of conducting RNA-based STR analysis using the D18S51 locus as a model.

8.
Forensic Sci Int ; 361: 112081, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38850616

RESUMO

Forensic sample screening is important for establishing an effective DNA typing workflow. The detection of sex-specific markers in forensic samples highlights the necessity for further analysis. Y-chromosome DNA can confirm male contributions, but female contributions are difficult to confirm using DNA-based methods. To address this, we developed a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay targeting the long non-coding RNA X-inactive specific transcript (XIST) to screen female samples. Operating at 65 °C for 30 min, the assay yielded results discernible from the color change of the pH indicator dye. The assay showed a detection limit of approximately 0.5 µL of blood. The assay also detected XIST RNA in mixed body fluids and mock samples, indicating its potential applicability to casework samples. Taken together, our assay provides a rapid and simple strategy for screening female samples.


Assuntos
Colorimetria , Técnicas de Amplificação de Ácido Nucleico , RNA Longo não Codificante , Feminino , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA Longo não Codificante/genética , Limite de Detecção , Transcrição Reversa , Técnicas de Diagnóstico Molecular
9.
Forensic Sci Int ; 352: 111847, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37837846

RESUMO

Saliva samples are frequently collected at crime scenes. Salivary mRNA profiling, such as that of histatin 3 (HTN3), is a highly specific approach that overcomes the limitation of traditional amylase tests. However, typical mRNA detection methods based on reverse transcription PCR (RT-PCR) are time-consuming and labor-intensive. Here, we report a one-tube, two-step isothermal amplification assay for HTN3 mRNA, which enables rapid, simple, and sensitive screening of saliva. The first step is an RT-recombinase polymerase amplification (RT-RPA) assay at 42 °C for 20 min; the second step is a loop-mediated isothermal amplification (LAMP) assay at 65 °C for 30 min. The reactions can be performed in a closed tube, and the products are detected using real-time fluorescence analysis. The assay sensitivity was 0.5 µL of saliva samples. It also detected HTN3 mRNA in mixed and mock samples, demonstrating its applicability to actual forensic samples. These findings suggest that our strategy is promising for screening of saliva from forensic samples.


Assuntos
Histatinas , Saliva , RNA Mensageiro , Histatinas/genética , Sensibilidade e Especificidade , Medicina Legal
10.
Nat Commun ; 14(1): 652, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36746969

RESUMO

Organoboron and organosilicon compounds are used not only as synthetic building blocks but also as functional materials and pharmaceuticals, and compounds with multiple boryl and silyl groups are beginning to be used for these purposes. Especially in drug discovery, methodology providing easy stereoselective access to aliphatic nitrogen heterocycles bearing multiple boryl or silyl groups from readily available aromatic nitrogen heterocycles would be attractive. However, such transformations remain challenging, and available reactions have been mostly limited to dearomative hydroboration or hydrosilylation reactions. Here, we report the dearomative triple elementalization (carbo-sila-boration) of quinolines via the addition of organolithium followed by photo-boosted silaboration, affording the desired products with complete chemo-, regio-, and stereoselectivity. The reaction proceeds via the formation of silyl radicals instead of silyl anions. We also present preliminary studies to illustrate the potential of silaboration products as synthetic platforms.

11.
Regul Toxicol Pharmacol ; 62(3): 419-24, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22306441

RESUMO

The genotoxicity of fullerene C(60) nanoparticles was evaluated in vivo with comet assays using the lung cells of rats given C(60) nanoparticles. The C(60) nanoparticles were intratracheally instilled as a single dose at 0.5 or 2.5mg/kg or repeated dose at 0.1 or 0.5mg/kg, once a week for 5 weeks, to male rats. The lungs were obtained 3 or 24h after a single instillation and 3h after repeated instillation. Inflammatory responses were observed in the lungs obtained 24h after a single instillation at 2.5mg/kg and repeated instillation at 0.5mg/kg. Histopathological examinations revealed that C(60) nanoparticles caused slight changes including hemorrhages in alveoli and the cellular infiltration of macrophages and neutrophils in alveoli. In comet assays using rat lung cells, no increase in % Tail DNA was found in any group given C(60) nanoparticles. These findings indicate that C(60) nanoparticles had no potential for DNA damage in comet assays using the lungs cells of rats given C(60) even at doses causing inflammation.


Assuntos
Ensaio Cometa/métodos , Fulerenos/toxicidade , Pulmão/efeitos dos fármacos , Nanopartículas/toxicidade , Animais , Ensaio Cometa/normas , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/fisiologia , Fulerenos/administração & dosagem , Injeções Espinhais , Pulmão/citologia , Pulmão/fisiologia , Masculino , Testes de Mutagenicidade/métodos , Testes de Mutagenicidade/normas , Nanopartículas/administração & dosagem , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley
12.
Regul Toxicol Pharmacol ; 64(1): 124-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22735368

RESUMO

The genotoxicity of single-wall carbon nanotubes (SWCNTs) was evaluated in vivo using the comet assay after intratracheal instillation in rats. The SWCNTs were instilled at a dosage of 0.2 or 1.0mg/kg body weight (single instillation group) and 0.04 or 0.2mg/kg body weight once a week for 5weeks (repeated instillation group). As a negative control, 1% Tween 80 was instilled in a similar manner. As a positive control, ethyl methanesulfonate (EMS) at 500mg/kg was administered once orally 3h prior to dissection. Histopathologically, inflammation in the lung was observed for all the SWCNTs in both single and repeated groups. In the comet assay, there was no increase in% tail DNA in any of the SWCNT-treated groups. In the EMS-treated groups, there was a significant increase in% tail DNA compared with the negative control group. The present study indicated that a single intratracheal instillation of SWCNTs (1.0mg/kg) or repeated intratracheal instillation (0.2mg/kg) once a week for five weeks induced a clear inflammatory response (hemorrhage in the alveolus, infiltration of alveolar macrophages and neutrophiles), but no DNA damage, in the lungs in rats. Under the conditions of the test, SWCNTs were not genotoxic in the comet assay following intratracheal instillation in rats.


Assuntos
Mutagênicos/toxicidade , Nanotubos de Carbono/toxicidade , Animais , Ensaio Cometa , Dano ao DNA , Exposição por Inalação/efeitos adversos , Intubação Intratraqueal/efeitos adversos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Mutagênicos/administração & dosagem , Mutagênicos/classificação , Nanotubos de Carbono/classificação , Pneumonia/induzido quimicamente , Pneumonia/patologia , Ratos , Ratos Endogâmicos
13.
Kyobu Geka ; 65(3): 252-4, 2012 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-22374605

RESUMO

We report a rare case of mediastinal desmoid tumor in a 17-year-old man. The patient was a 17-year old man who had underwent surgery for mediastinal tumor at our hospital 2 years before. The tumor was diagnosed as a solitary fibrous tumor of the mediastinum. After 2 years, chest computed tomography(CT) and magnetic resonance imaging( MRI) showed a mass at the previously resected site. Surgery was performed again under the diagnosis of recurrent tumor. The tumor densely adhered to the superior vena cava, right innominate vein, pericardium, and the right lung. The tumor was completely resected with the aid of the partial extracorporeal circulation. Finally, both previously resected tumor and the recurrent tumor were diagnosed pathologically as desmoid tumors.


Assuntos
Fibromatose Agressiva/cirurgia , Neoplasias do Mediastino/cirurgia , Adolescente , Fibromatose Agressiva/patologia , Humanos , Masculino , Neoplasias do Mediastino/patologia , Recidiva Local de Neoplasia
14.
PLoS One ; 17(1): e0262577, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35020776

RESUMO

cAMP responsive element binding protein (CREB)-regulated transcription coactivators (CRTCs) regulate gene transcription in response to an increase in intracellular cAMP or Ca2+ levels. To date, three isoforms of CRTC have been identified in mammals. All CRTCs are widely expressed in various regions of the brain. Numerous studies have shown the importance of CREB and CRTC in energy homeostasis. In the brain, the paraventricular nucleus of the hypothalamus (PVH) plays a critical role in energy metabolism, and CRTC1 and CRTC2 are highly expressed in PVH neuronal cells. The single-minded homolog 1 gene (Sim1) is densely expressed in PVH neurons and in some areas of the amygdala neurons. To determine the role of CRTCs in PVH on energy metabolism, we generated mice that lacked CRTC1 and CRTC2 in Sim1 cells using Sim-1 cre mice. We found that Sim1 cell-specific CRTC1 and CRTC2 double-knockout mice were sensitive to high-fat diet (HFD)-induced obesity. Sim1 cell-specific CRTC1 and CRTC2 double knockout mice showed hyperphagia specifically for the HFD, but not for the normal chow diet, increased fat mass, and no change in energy expenditure. Interestingly, these phenotypes were stronger in female mice than in male mice, and a weak phenotype was observed in the normal chow diet. The lack of CRTC1 and CRTC2 in Sim1 cells changed the mRNA levels of some neuropeptides that regulate energy metabolism in female mice fed an HFD. Taken together, our findings suggest that CRTCs in Sim1 cells regulate gene expression and suppress excessive fat intake, especially in female mice.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Dieta Hiperlipídica , Metabolismo Energético , Hiperfagia/patologia , Obesidade/patologia , Proteínas Repressoras/metabolismo , Fatores de Transcrição/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Comportamento Alimentar , Feminino , Hiperfagia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/metabolismo , Proteínas Repressoras/genética
15.
Endocrinology ; 162(9)2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33846709

RESUMO

Cyclic adenosine monophosphate responsive element-binding protein-1-regulated transcription coactivator-1 (CRTC1) is a cytoplasmic coactivator that translocates to the nucleus in response to cyclic adenosine monophosphate. Whole-body knockdown of Crtc1 causes obesity, resulting in increased food intake and reduced energy expenditure. CRTC1 is highly expressed in the brain; therefore, it might play an important role in energy metabolism via the neuronal pathway. However, the precise mechanism by which CRTC1 regulates energy metabolism remains unknown. Here, we showed that mice lacking CRTC1, specifically in steroidogenic factor-1 expressing cells (SF1 cells), were sensitive to high-fat diet (HFD)-induced obesity, exhibiting hyperphagia and increased body weight gain. The loss of CRTC1 in SF1 cells impaired glucose metabolism. Unlike whole-body CRTC1 knockout mice, SF1 cell-specific CRTC1 deletion did not affect body weight gain or food intake in normal chow feeding. Thus, CRTC1 in SF1 cells is required for normal appetite regulation in HFD-fed mice. CRTC1 is primarily expressed in the brain. Within the hypothalamus, which plays an important role for appetite regulation, SF1 cells are only found in ventromedial hypothalamus. RNA sequencing analysis of microdissected ventromedial hypothalamus samples revealed that the loss of CRTC1 significantly changed the expression levels of certain genes. Our results revealed the important protective role of CRTC1 in SF1 cells against dietary metabolic imbalance.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Hiperfagia/etiologia , Obesidade/etiologia , Fator Esteroidogênico 1/metabolismo , Fatores de Transcrição/genética , Glândulas Suprarrenais/citologia , Glândulas Suprarrenais/metabolismo , Animais , Encéfalo/citologia , Encéfalo/metabolismo , Metabolismo Energético/genética , Hiperfagia/genética , Hiperfagia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Neurônios/metabolismo , Obesidade/genética , Obesidade/metabolismo , Fator Esteroidogênico 1/genética
16.
Nat Commun ; 12(1): 843, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594062

RESUMO

Adaptive thermogenesis is essential for survival, and therefore is tightly regulated by a central neural circuit. Here, we show that microRNA (miR)-33 in the brain is indispensable for adaptive thermogenesis. Cold stress increases miR-33 levels in the hypothalamus and miR-33-/- mice are unable to maintain body temperature in cold environments due to reduced sympathetic nerve activity and impaired brown adipose tissue (BAT) thermogenesis. Analysis of miR-33f/f dopamine-ß-hydroxylase (DBH)-Cre mice indicates the importance of miR-33 in Dbh-positive cells. Mechanistically, miR-33 deficiency upregulates gamma-aminobutyric acid (GABA)A receptor subunit genes such as Gabrb2 and Gabra4. Knock-down of these genes in Dbh-positive neurons rescues the impaired cold-induced thermogenesis in miR-33f/f DBH-Cre mice. Conversely, increased gene dosage of miR-33 in mice enhances thermogenesis. Thus, miR-33 in the brain contributes to maintenance of BAT thermogenesis and whole-body metabolism via enhanced sympathetic nerve tone through suppressing GABAergic inhibitory neurotransmission. This miR-33-mediated neural mechanism may serve as a physiological adaptive defense mechanism for several stresses including cold stress.


Assuntos
MicroRNAs/metabolismo , Sistema Nervoso Simpático/fisiologia , Termogênese/genética , Tecido Adiposo Marrom/fisiologia , Animais , Temperatura Corporal/fisiologia , Peso Corporal , Encéfalo/metabolismo , Linhagem Celular , Temperatura Baixa , Dieta Hiperlipídica , Estresse do Retículo Endoplasmático , Humanos , Integrases/metabolismo , Masculino , Camundongos , Camundongos Obesos , MicroRNAs/genética , Consumo de Oxigênio/fisiologia , Fenótipo , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Receptores de GABA-A/genética , Receptores de GABA-A/metabolismo
17.
Org Lett ; 22(18): 7181-7186, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32806145

RESUMO

It has been established that an unsubstituted cyclopentadienyl (Cp) Rh(III) complex is an effective catalyst for the oxidative ortho-olefination of phenyl carbamates with both acrylates and styrenes under mild conditions. In addition, diolefination of a protected BINOL (1,1'-binaphthalene-2,2'-diol) proceeded in high yields and disubstituted acrylates could participate in this catalysis. Experimental and theoretical mechanistic studies elucidated that an electron-deficient nature of the unsubstituted CpRh(III) complex accelerates both the electrophilic aryl C-H rhodation and the rate-limiting alkene insertion steps.

18.
Mutagenesis ; 24(1): 9-16, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18765420

RESUMO

The partial hepatectomy method, co-treatment method with mitogens and an in vivo/in vitro assay method have been reported as in vivo liver micronucleus (MN) assays. These methods have disadvantages with respect to widespread use as an in vivo assay, i.e. they are time consuming, labour intensive and there is the possibility of interaction with the mitogens used. Therefore, we have attempted to develop a new method to overcome these disadvantages. The assay as described herein utilises the autonomous proliferation of hepatocytes of young rats. Nine chemicals have been evaluated using this method thus far. We have also assessed the sensitivity and detectability according to the following methods. A liver MN assay was performed in two strains of young rats using one or two doses of 12 chemicals to investigate the inducibility of micronucleated hepatocytes. For some of the chemicals, a peripheral blood MN assay was performed concurrently in the same animals. The following chemicals were used: diethylnitrosamine (DEN), 2-acetylaminofluorene (2AAF), 2,4-diaminotoluene (2,4-DAT), quinoline, p-dimethylaminoazobenzene (DAB), dimethylnitrosamine (DMN), ethylmethanesulphonate, 5-fluorouracil, mitomycin C (MMC), 1,2-dimethylhydrazine.2HCl, cyclophosphamide and 2,4-dinitrotoluene (2,4-DNT). The rodent hepatocarcinogens, quinoline, DAB and DMN showed positive responses in previous assays. The results of the present assay revealed new positive responses for single doses of 2AAF, 2,4-DAT, MMC, 1,2-dimethylhydrazine.2HCl and 2,4-DNT. These chemicals are known rodent hepatocarcinogens, whose clastogenicity is believed to be related to the formation of reactive metabolites generated through enzymatic activation, or the chemicals act directly. Two doses of 2AAF and DMN appeared to be more effective than a single dose in terms of MN induction. Although there were quantitative differences in the incidences of MNs, both strains of rat (F344 and SD) responded positively after treatment with DEN, DMN, 2,4-DAT, DAB, quinoline and 2AAF, suggesting that both strains are appropriate for the assay. Based on these results, it is concluded that this technique could be effective for detecting chemical clastogenicity in hepatocytes in vivo.


Assuntos
Dano ao DNA , Hepatócitos/efeitos dos fármacos , Testes para Micronúcleos/métodos , Mutagênicos/toxicidade , Animais , Proliferação de Células , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos F344
19.
Ann Thorac Cardiovasc Surg ; 14(2): 123-5, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18414353

RESUMO

Open heart surgery in patients with myelodysplastic syndrome (MDS) increases the risk of bleeding and infection. We document a 78-year-old female with severe aortic valve stenosis and MDS who underwent aortic valve replacement with stentless porcine prosthesis. Perioperatively, a transfusion of red blood cells (RBCs) and an infusion of granulocyte colony-stimulating factor (G-CSF) were needed for serious erythrocytopenia and leukocytopenia. We did not need a large amount of RBC transfusions in the postoperative course, and no infection was seen postoperatively.


Assuntos
Estenose da Valva Aórtica/complicações , Estenose da Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Síndromes Mielodisplásicas/complicações , Idoso , Estenose da Valva Aórtica/sangue , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/patologia , Bioprótese , Ponte Cardiopulmonar , Contagem de Eritrócitos , Transfusão de Eritrócitos , Feminino , Próteses Valvulares Cardíacas , Humanos , Complicações Intraoperatórias/terapia , Leucopenia/terapia , Síndromes Mielodisplásicas/sangue , Ultrassonografia
20.
Int J Toxicol ; 27 Suppl 3: 59-72, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19037799

RESUMO

A series of studies was performed to evaluate the safety of dihydrocapsiate (4-hydroxy-3-methoxybenzyl 8-methylnonanoate; CAS no. 205687-03-2). This study evaluated the potential genotoxicity of this compound using a variety of in vitro and in vivo test systems, including bacterial reverse mutation test, chromosomal aberration test, micronucleus test, gene mutation assay with transgenic rats, and single-cell gel (SCG) assay (Comet assay). In vitro tests (bacterial reverse mutation test and chromosomal aberration test) produced positive results in the absence of metabolic activation, but negative results in the presence of metabolic activation. The in vivo gene mutation assay (with transgenic rats) produced negative results, as did the in vivo mouse micronucleus assay, which failed to induce micronucleated polychromatic erythrocytes. Although the rat SCG assay produced statistically significant increases in the Olive tail moment and % tail DNA of the liver and intestine in the 2000 mg/kg group (compared with the negative-control group), a number of factors caused the authors to question the validity of these findings. Taken together, these results suggest that dihydrocapsiate has a low or extremely low likelihood of inducing genotoxicity.


Assuntos
Capsaicina/análogos & derivados , Animais , Biotransformação , Capsaicina/toxicidade , Aberrações Cromossômicas , Ensaio Cometa , Masculino , Camundongos , Testes para Micronúcleos , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos
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