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2.
Med Oral Patol Oral Cir Bucal ; 27(3): e294-e300, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35368004

RESUMO

BACKGROUND: The healthcare practice of dentistry, as well as medicine, is framed within a legal environment. Patients have the right to know all the information related to any action performed on them and dental or medical doctors are obliged to obtain their patient's prior written informed consent (IC) before undertaking any healthcare procedures. MATERIAL AND METHODS: Here we reviewed the legality and jurisprudence in Spain regarding IC. We also used INFLESZ text readability analysis software to analyse a sample of official Spanish informed consent documents (ICDs) from different surgical and interventional procedures related to dentistry and oral cavity interventions. RESULTS: It is a mistake to confound IC with ICDs. This error prevents physicians from considering the former as a care process in which the patient's authorisation signature is the last link in a chain formed, almost in its entirety, by the informative process and deliberation alongside the patient. Multiple factors can influence communication between practitioners and their patients. Importantly, treatment adherence is greater when patients feel involved and autonomous in shared decision-making and when the circumstances of their lives are adequately considered. We concluded that although the ICDs we analysed conformed to the requirements set out in international law, they were somewhat difficult to read according to the reading habits of the general Spanish population. CONCLUSIONS: Knowledge about the legality of IC helps professionals to understand the problems that may arise from their non-compliance. This is because the omission or defective fulfilment of IC obligations is the origin of legal responsibility for medical practitioners. In this sense, to date, there have been more convictions for defective ICs than for malpractice. The information provided in ICs should include the risks, benefits, and treatment alternatives and must be tailored to the needs and capabilities of the patient to enable autonomous decision-making.


Assuntos
Termos de Consentimento , Consentimento Livre e Esclarecido , Compreensão , Odontologia , Humanos , Espanha
3.
Arch. Soc. Esp. Oftalmol ; 94(12): 619-621, dic. 2019. ilus
Artigo em Espanhol | IBECS | ID: ibc-190016

RESUMO

Las perforaciones oculares precisan de una actuación acorde a la severidad de los hallazgos. Adicionalmente, la vecindad de la órbita a la cavidad nasal y a la fosa cerebral anterior obliga al menos a descartar daño asociado en estos espacios. La coexistencia de una herida ocular penetrante con secreción nasal homolateral, en la que se detecta β2-transferrina -marcador de alta especificidad y sensibilidad para presencia de líquido cefalorraquídeo- obliga a sospechar y localizar una fístula del mismo. Presentamos un caso en el que la detección de esta proteína desializada en una rinorrea postraumática tenía su origen en el propio globo ocular, y convirtió el diagnóstico de fístula de líquido cefalorraquídeo en un falso positivo


Ocular perforations require an action depending on the findings observed. Additionally, the closeness of the orbit to the nasal cavity and the anterior cranial fossa requires any collateral damage in these spaces to be ruled out. The presence of a penetrating ocular injury associated with ipsilateral rhinorrhoea in which the presence of β2-transferrin -a highly specific and sensitive marker to identify cerebrospinal fluid- is detected, obliges to suspect and locate any possible leakage. A case is presented in which this unbound protein is detected in post-traumatic rhinorrhoea with an origin in the eyeball, making the diagnosis of a CSF leak into a false positive


Assuntos
Humanos , Feminino , Adulto , Ferimentos Oculares Penetrantes/diagnóstico por imagem , Transferrina/análise , Humor Aquoso , Biomarcadores/análise , Rinorreia de Líquido Cefalorraquidiano/diagnóstico por imagem , Reações Falso-Positivas , Fístula/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Hemorragia Vítrea/etiologia
4.
Arch Soc Esp Oftalmol (Engl Ed) ; 94(12): 619-621, 2019 Dec.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31311689

RESUMO

Ocular perforations require an action depending on the findings observed. Additionally, the closeness of the orbit to the nasal cavity and the anterior cranial fossa requires any collateral damage in these spaces to be ruled out. The presence of a penetrating ocular injury associated with ipsilateral rhinorrhoea in which the presence of ß2-transferrin -a highly specific and sensitive marker to identify cerebrospinal fluid- is detected, obliges to suspect and locate any possible leakage. A case is presented in which this unbound protein is detected in post-traumatic rhinorrhoea with an origin in the eyeball, making the diagnosis of a CSF leak into a false positive.


Assuntos
Ferimentos Oculares Penetrantes/diagnóstico por imagem , Transferrina/análise , Adulto , Humor Aquoso , Biomarcadores/análise , Rinorreia de Líquido Cefalorraquidiano/diagnóstico por imagem , Reações Falso-Positivas , Feminino , Fístula/diagnóstico por imagem , Humanos , Tomografia Computadorizada por Raios X , Hemorragia Vítrea/etiologia
5.
Cell Death Dis ; 6: e1763, 2015 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-25973683

RESUMO

Here we study links between aminoglycoside-induced mistranslation, protein misfolding and neuropathy. We demonstrate that aminoglycosides induce misreading in mammalian cells and assess endoplasmic reticulum (ER) stress and unfolded protein response (UPR) pathways. Genome-wide transcriptome and proteome analyses revealed upregulation of genes related to protein folding and degradation. Quantitative PCR confirmed induction of UPR markers including C/EBP homologous protein, glucose-regulated protein 94, binding immunoglobulin protein and X-box binding protein-1 (XBP1) mRNA splicing, which is crucial for UPR activation. We studied the effect of a compromised UPR on aminoglycoside ototoxicity in haploinsufficient XBP1 (XBP1(+/-)) mice. Intra-tympanic aminoglycoside treatment caused high-frequency hearing loss in XBP1(+/-) mice but not in wild-type littermates. Densities of spiral ganglion cells and synaptic ribbons were decreased in gentamicin-treated XBP1(+/-) mice, while sensory cells were preserved. Co-injection of the chemical chaperone tauroursodeoxycholic acid attenuated hearing loss. These results suggest that aminoglycoside-induced ER stress and cell death in spiral ganglion neurons is mitigated by XBP1, masking aminoglycoside neurotoxicity at the organismal level.


Assuntos
Proteínas de Ligação a DNA/genética , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Gentamicinas/farmacologia , Perda Auditiva de Alta Frequência , Ácido Tauroquenodesoxicólico/farmacologia , Fatores de Transcrição/genética , Animais , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Retículo Endoplasmático/patologia , Feminino , Células HEK293 , Células Ciliadas Auditivas/patologia , Perda Auditiva de Alta Frequência/induzido quimicamente , Perda Auditiva de Alta Frequência/genética , Perda Auditiva de Alta Frequência/patologia , Humanos , Masculino , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos CBA , Neurônios/patologia , Biossíntese de Proteínas/efeitos dos fármacos , Dobramento de Proteína , Deficiências na Proteostase , Splicing de RNA/genética , Fatores de Transcrição de Fator Regulador X , Gânglio Espiral da Cóclea/citologia , Gânglio Espiral da Cóclea/efeitos dos fármacos , Gânglio Espiral da Cóclea/patologia , Fatores de Transcrição/metabolismo , Resposta a Proteínas não Dobradas/genética , Resposta a Proteínas não Dobradas/fisiologia , Proteína 1 de Ligação a X-Box
6.
Neuroimage ; 36(4): 1301-12, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17524671

RESUMO

To clarify the physiological significance of task-related change of the regional electroencephalogram (EEG) rhythm, we quantitatively evaluated the correlation between regional cerebral blood flow (rCBF) and EEG power. Eight subjects underwent H2 15O positron emission tomography scans simultaneously with EEG recording during the following tasks: rest condition with eyes closed and open, self-paced movements of the right and left thumb and right ankle. EEG signals were recorded from the occipital and bilateral sensorimotor areas. Cortical activation associated with EEG rhythm generation was studied by the correlation between rCBF and EEG power. There were significant negative correlations between the sensorimotor EEG rhythm at 10-20 Hz on each side and the ipsilateral sensorimotor rCBF and between the occipital EEG rhythm at 10-20 Hz and the occipital rCBF. The occipital EEG rhythm showed a positive correlation with the bilateral medial prefrontal rCBF, while the right sensorimotor EEG rhythm showed a positive correlation with the left prefrontal rCBF. In conclusion, decrease in the regional EEG rhythm at 10-20 Hz might represent the neuronal activation of the cortex underlying the electrodes, at least for the visual and sensorimotor areas. The neural network including the prefrontal cortex could play an important role to generate the EEG rhythm.


Assuntos
Nível de Alerta/fisiologia , Córtex Cerebral/irrigação sanguínea , Eletroencefalografia , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Atividade Motora/fisiologia , Tomografia por Emissão de Pósitrons , Processamento de Sinais Assistido por Computador , Transmissão Sináptica/fisiologia , Adulto , Mapeamento Encefálico , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Dominância Cerebral/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Motor/irrigação sanguínea , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiologia , Rede Nervosa/irrigação sanguínea , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiologia , Neurônios/fisiologia , Lobo Occipital/irrigação sanguínea , Lobo Occipital/diagnóstico por imagem , Lobo Occipital/fisiologia , Córtex Pré-Frontal/irrigação sanguínea , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Valores de Referência , Fluxo Sanguíneo Regional/fisiologia , Córtex Somatossensorial/irrigação sanguínea , Córtex Somatossensorial/diagnóstico por imagem , Córtex Somatossensorial/fisiologia , Estatística como Assunto
7.
Neurology ; 65(11): 1708-15, 2005 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-16344511

RESUMO

BACKGROUND: Patients with Parkinson disease (PD) often experience visual hallucinations (VH) with retained insight (nonpsychotic) but the precise mechanism remains unclear. OBJECTIVE: To clarify which neural substrates participate in nonpsychotic VH in PD, the authors evaluated regional cerebral blood flow (rCBF) changes in patients with PD and VH. METHODS: The authors compared 24 patients with PD who had nonpsychotic VH (hallucinators) and 41 patients with PD who had never experienced VH (non-hallucinators) using SPECT images with N-isopropyl-p-[(123)I]iodoamphetamine. There were no significant differences in age, sex, duration of disease, doses of PD medications, Hoehn and Yahr scale, or Mini-Mental State Examination (MMSE) scores between the two groups. The rCBF data were analyzed using statistical parametric mapping (SPM). RESULTS: The rCBF in the right fusiform gyrus was lower in the hallucinators than in the non-hallucinators (corrected p < 0.05 at cluster levels). The hallucinators revealed higher rCBF in the right superior and middle temporal gyri than the non-hallucinators (uncorrected p < 0.001). These significant differences were demonstrated after MMSE scores and duration of disease, which are the relevant factors associated with VH, were covariated out. CONCLUSIONS: Nonpsychotic visual hallucinations in Parkinson disease (PD) may be associated with hypoperfusion in the right fusiform gyrus and hyperperfusion in the right superior and middle temporal gyri. These temporal regions are important for visual object recognition and these regional cerebral blood flow changes are associated with inappropriate visual processing and are responsible for nonpsychotic visual hallucinations in PD.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/fisiopatologia , Circulação Cerebrovascular/fisiologia , Alucinações/fisiopatologia , Doença de Parkinson/fisiopatologia , Idoso , Encéfalo/diagnóstico por imagem , Feminino , Alucinações/diagnóstico por imagem , Alucinações/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Valor Preditivo dos Testes , Lobo Temporal/irrigação sanguínea , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único , Córtex Visual/irrigação sanguínea , Córtex Visual/diagnóstico por imagem , Córtex Visual/fisiopatologia , Vias Visuais/irrigação sanguínea , Vias Visuais/diagnóstico por imagem , Vias Visuais/fisiopatologia , Percepção Visual/fisiologia
9.
Br J Ophthalmol ; 86(12): 1363-6, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12446366

RESUMO

AIM: To examine the relation between aldose reductase (AR) and the development and progression of diabetic retinopathy by comparing the erythrocyte AR levels with the prevalence of diabetic retinopathy in NIDDM patients. METHODS: A clinic based cross sectional study was used. 611 NIDDM patients and 73 controls were enrolled. Erythrocyte AR levels were determined by ELISA. These AR levels were then correlated with patient age, duration of diabetes, and HbA(1c) levels. AR levels were also correlated with the prevalence of diabetic retinopathy in the entire NIDDM patient group and in three subgroups formed by separating the NIDDM patients by their duration of diabetes. The prevalence of diabetic retinopathy significantly increased with increased erythrocyte AR levels in patients with duration of diabetes of less than 10 years. A similar, but non-significant correlation between the prevalence of retinopathy and increased erythrocyte AR levels was observed in patients with diabetes duration of 10-20 and >/=20 years. RESULTS: The prevalence of diabetic retinopathy increased with increased erythrocyte AR levels in NIDDM patients with a duration of diabetes of less than 10 years. CONCLUSION: It was suggested that the inhibition of AR in patients with early NIDDM might be beneficial in reducing the development of diabetic retinopathy.


Assuntos
Aldeído Redutase/análise , Diabetes Mellitus Tipo 2/enzimologia , Retinopatia Diabética/enzimologia , Eritrócitos/enzimologia , Adulto , Fatores Etários , Biomarcadores/análise , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/sangue , Retinopatia Diabética/complicações , Ensaio de Imunoadsorção Enzimática , Feminino , Hemoglobina A/análise , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
10.
Fukuoka Igaku Zasshi ; 92(5): 167-76, 2001 May.
Artigo em Japonês | MEDLINE | ID: mdl-11452514

RESUMO

In vitro Metabolism of 2,4,5,2',3',4'-hexachlorobiphenyl (CB138) was studied using liver microsomes from rats, hamsters and guinea pigs. Guinea pig liver microsomes formed four metabolites named as M-1, M-2, M-3 and M-4 and these metabolites were all increased to about 4-5 fold of untreated microsomes by pretreatment of phenobarbital. Liver microsomes of rats and hamsters showed much less activity to metabolize CB138 than those of guinea pigs. Only phenobarbital-treated microsomes produced very small amounts of M-3 in rats and M-1, M-2 and M-3 in hamsters, but untreated and MC-treated microsomes did not. When mass spectra of the methylated derivatives of M-1, M-2, M-3 and M-4 were measured in GC/MS, the former two possess the molecular ion of 354 and the latter two had the molecular ion of 388. In addition, the mass fragmentation pattern indicated that M-1, M-2, M-3 and M-4 are 2-OH-4,5,2',3',4'-pentachlorobiphenyl, 5-OH-2,4,2',3',4'-pentachlorobiphenyl, 3-OH-CB138 and 2-OH-3,4,5,2',3',4'-hexachlorobiphenyl, respectively. Of four metabolites, the chemical structures of M-3 and M-4 were supported by the synthesized authentic compounds. From these results, it is suggested that the metabolism of CB138 in guinea pig liver proceeds mainly via 2,3-epoxide as an intermediate and a PB-inducible P450, CYP2B18, is the most important isozyme in CB138 metabolism.


Assuntos
Fígado/metabolismo , Bifenilos Policlorados/metabolismo , Animais , Cricetinae , Cromatografia Gasosa-Espectrometria de Massas , Cobaias , Masculino , Ratos , Ratos Wistar , Especificidade da Espécie , Análise Espectral
11.
Biochem Biophys Res Commun ; 285(4): 1007-11, 2001 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-11467852

RESUMO

Living organisms have been known to spontaneously emit ultraweak photons in vivo and in vitro. Origin of the photon emission remains unclear, especially in the nervous system. The spontaneous ultraweak photon emission was detected here from cultured rat cerebellar granule neurons using a photomultiplier tube which was highly sensitive to visible light. The photon emission was facilitated by the membrane depolarization of neurons by a high concentration of K+ and was attenuated by application of tetrodotoxin or removal of extracellular Ca2+, indicating the photon emission depending on the neuronal activity and likely on the cellular metabolism. Furthermore, almost all the photon emission was arrested by 2,4-dinitrophenylhydrazine, indicating that the photon emission would be derived from oxidized molecules. Detection of the spontaneous ultraweak photon emission will realize noninvasive and real-time monitoring of the redox state of neural tissue corresponding to the neuronal activity and metabolism.


Assuntos
Neurônios/fisiologia , Fótons , Animais , Células Cultivadas , Cerebelo/citologia , Luz , Masculino , Rede Nervosa/fisiologia , Neurônios/citologia , Oxirredução , Estresse Oxidativo/fisiologia , Fenil-Hidrazinas/farmacologia , Fotometria/instrumentação , Ratos , Transmissão Sináptica/fisiologia
12.
Cancer Gene Ther ; 8(4): 285-93, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11393281

RESUMO

Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV8) has been etiologically associated with several malignancies including Kaposi's sarcoma and primary effusion lymphoma. Oncogenic viral interferon regulatory factor (vIRF) encoded by KSHV ORF-K9 is a homologue of cellular interferon regulatory factor (IRF), and has been demonstrated to inhibit type I/II interferon signal transduction and transform NIH3T3 cells through the interactions with IRF-1, IRF-3, and CBP/p300 proteins. To counteract vIRF's pathogenic role, we have developed five ribozymes targeting ORF-K9 mRNA to suppress vIRF expression. The vIRF RNA substrates were cleaved up to 80% in a substrate-specific manner in transcript cleavage assays in vitro. In a transient transfection assay, two of the ribozymes efficiently suppressed the expression of vIRF protein measured by dual-color immunofluorescence assay that simultaneously detects the expression of both vIRF protein and ribozyme. Flow cytometry analysis showed that these ribozymes reduced vIRF expression up to 76%. A mutant ribozyme had no cleavage activity in vitro, but exhibited antisense effect in vivo. These results suggest that the ribozymes may provide a new approach for functional knockout of vIRF gene, and are potential candidates of antiviral therapy for KSHV-related malignancies.


Assuntos
Proteínas de Ligação a DNA/genética , Herpesvirus Humano 8/genética , RNA Catalítico/farmacologia , Fatores de Transcrição/genética , Animais , Sequência de Bases , Proteínas de Ligação a DNA/metabolismo , Citometria de Fluxo , Imunofluorescência , Células HeLa/efeitos dos fármacos , Células HeLa/metabolismo , Células HeLa/virologia , Humanos , Técnicas In Vitro , Fatores Reguladores de Interferon , Camundongos , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/metabolismo , Transfecção , Proteínas Virais
13.
FEBS Lett ; 474(1): 16-22, 2000 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-10828443

RESUMO

We have cloned a novel unconventional myosin gene myoM in Dictyostelium. Phylogenetic analysis of the motor domain indicated that MyoM does not belong to any known subclass of the myosin superfamily. Following the motor domain, two calmodulin-binding IQ motifs, a putative coiled-coil region, and a Pro, Ser and Thr-rich domain, lies a combination of dbl homology and pleckstrin homology domains. These are conserved in Rho GDP/GTP exchange factors (RhoGEFs). We have identified for the first time the RhoGEF domain in the myosin sequences. The growth and terminal developmental phenotype of Dictyostelium cells were not affected by the myoM(-) mutation. Green fluorescent protein-tagged MyoM, however, accumulated at crown-shaped projections and membranes of phase lucent vesicles in growing cells, suggesting its possible roles in macropinocytosis.


Assuntos
Dictyostelium/química , Fatores de Troca do Nucleotídeo Guanina/química , Miosinas/química , Proteínas de Protozoários , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Calmodulina/metabolismo , Dictyostelium/genética , Dictyostelium/ultraestrutura , Proteínas de Fluorescência Verde , Humanos , Indicadores e Reagentes , Proteínas Luminescentes , Dados de Sequência Molecular , Miosinas/análise , Miosinas/genética , Filogenia , Fatores de Troca de Nucleotídeo Guanina Rho , Alinhamento de Sequência
14.
Jpn J Ophthalmol ; 44(2): 132-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10715379

RESUMO

PURPOSE: A prospective study was performed to investigate changes in corneal shape and axial length following scleral buckling surgery. METHODS: We investigated the changes in corneal shape, refraction, and axial length following scleral buckling surgery in 24 patients who underwent local buckling and 14 patients who underwent encircling with additional segmental buckling. The corneal shape was determined by corneal topography and autokeratometry, refraction was measured by autorefractometry, and axial length was measured by A-mode ultrasonography before surgery, and 1, 2, and 7 days, and 1, 3, and 6 months after surgery. RESULTS: After local buckling, the axial length shortened and a hyperopic change was observed. After encircling with additional segmental buckling, the axial length elongated and a myopic shift was detected. The direction of the surgically induced corneal astigmatic vectors was almost identical to the direction of the buckle. There was a tendency for shorter distances between the limbus and the buckle to be associated with greater absolute values. Astigmatism gradually decreased following surgery and stabilized in about 3 months. CONCLUSIONS: Surgeons should select a surgical procedure to ensure favorable postoperative visual acuity while minimizing changes in the shape of the cornea.


Assuntos
Córnea/patologia , Refração Ocular , Descolamento Retiniano/cirurgia , Perfurações Retinianas/cirurgia , Recurvamento da Esclera , Astigmatismo/etiologia , Astigmatismo/fisiopatologia , Humanos , Complicações Pós-Operatórias , Período Pós-Operatório , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento
15.
Nihon Rinsho ; 57 Suppl: 172-5, 1999 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-10543080

Assuntos
Biotina/sangue , Humanos
16.
Fukuoka Igaku Zasshi ; 90(5): 220-30, 1999 May.
Artigo em Japonês | MEDLINE | ID: mdl-10396878

RESUMO

In vitro metabolism of 3,5,3',4'-, 3,5,3',5'- and 2,4,3',4'-tetrachlorobiphenyls (TCBs) was studied using liver microsomes from rats, guinea pigs and hamsters. 3,5,3',4'-TCB was metabolized to 4-hydroxy-3,5,3',4'-TCB with liver microsomes of 3-methyl-cholanthrene (MC)- and 3,4,5,3',4'-pentachlorobiphenyl (PenCB)-treated rats but not of phenobarbital (PB)-treated ones. This result suggests that a MC-inducible cytochrome P450 isoform, probably CYP1A1, is more important in the in vitro metabolism of 3,5,3',4'-TCB in rat liver and that the isoform attacks the 3,5-dichloro-substituted phenyl ring more predominantly than 3,4-dichloro-substituted one. In 3,5,3',5'-TCB metabolism, liver microsomes from MC- and 3,4,5,3',4'-PenCB-treated hamsters formed 4-hydroxy-3,5,3',5'-TCB to a similar extent to rats reported previously. Guinea pig liver microsomes formed no metabolite. In 2,4,3',4'-TCB metabolism, PB accelerated 3-, 5- and 4-hydroxylations in guinea pigs and also 3- and 5-hydroxylations in hamsters, suggesting the involvement of a PB-inducible P450 isoform, presumably P450GP-1 and P450HPB-1, respectively. On the other hands, MC- and 3,4,5,3',4'-PenCB-treatment resulted in the marked increase of 4-hydroxylation in hamsters, but in the suppression of 4-hydroxylation in guinea pigs. From these results, it is suggested that the hydroxylation of coplanar TCBs such as 3,5,3',4'- and 3,5,3',5'-TCB is catalyzed by a MC-inducible P450 in rats and hamsters, whereas non-coplanar TCBs such as 2,4,3',4'-TCB which possesses both PB- and MC-like inducing ability of liver enzymes are metabolized by one or more kinds of P450 isoform induced by PB and MC.


Assuntos
Poluentes Ambientais/metabolismo , Microssomos Hepáticos/metabolismo , Bifenilos Policlorados/metabolismo , Animais , Células Cultivadas , Cricetinae , Sistema Enzimático do Citocromo P-450/metabolismo , Cobaias , Humanos , Hidroxilação , Isoenzimas/metabolismo , Masculino , Microssomos Hepáticos/enzimologia , Ratos , Ratos Wistar , Especificidade da Espécie
17.
Biochem Biophys Res Commun ; 261(2): 276-82, 1999 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-10425178

RESUMO

Elasticity of a two-dimensionally arranged myosin subfragment-1 (S1) was measured by using a surface forces apparatus. To prepare a two-dimensionally arranged S1-monolayer on a functionalized silver surface, we used genetically engineered Dictyostelium S1 molecules. A highly reactive cysteine residue was fused to the COOH-terminus using the recombinant DNA method. On the other hand, the maleimide groups was self-assembled onto a silver surface. Then the mutant S1 molecules were chemically bound to the functionalized silver surface at its COOH-terminus. This arrangement technique was necessary in order to create a stable S1-monolayer by chemical bond formation onto the silver surface. The occupied area of the single S1 on the silver surface was about 110 nm(2). In the interaction between the S1-monolayer and mica surfaces in aqueous solution, a long-range attractive force was observed. The elastic constants (stiffness and Young's modulus) of myosin S1 were evaluated from force-distance profiles in aqueous solution, using the Hertz theory. We found that the stiffness (or spring constant) and Young's modulus of S1 in the absence of nucleotide are 4.4 +/- 1.0 pN/nm and 0.71 +/- 0.16 GPa, respectively.


Assuntos
Mutação , Subfragmentos de Miosina/química , Subfragmentos de Miosina/genética , Silicatos de Alumínio , Sequência de Aminoácidos , Animais , Biofísica/instrumentação , Dictyostelium/genética , Elasticidade , Contração Muscular/fisiologia , Engenharia de Proteínas , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Prata , Propriedades de Superfície
19.
Arch Dis Child ; 78(3): 240-4, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9613354

RESUMO

AIM: To evaluate the clinical significance of soluble thrombomodulin and antiendothelial cell antibodies (AECA) in children with Henoch-Schönlein purpura. METHODS: Binding of serum AECA to bovine glomerular endothelial cells was evaluated by enzyme linked immunosorbent assay, cytotoxicity against glomerular endothelial cells by spectrophotometric assay, and soluble thrombomodulin concentrations by sandwich enzyme immunoassay. RESULTS: IgA AECA were detected in seven of 15 patients with Henoch-Schönlein purpura and nephritis, but were not detected in patients without nephritis or in controls. Patients with Henoch-Schönlein nephritis had raised titres of IgA AECA and serum thrombomodulin; severe proteinuria and renal histological changes were associated with raised titres of IgA AECA and raised serum thrombomodulin. No subjects had complement dependent cytotoxicity against glomerular endothelial cells. CONCLUSIONS: High titres of IgA AECA and raised serum thrombomodulin may be clinically useful markers of renal involvement in patients with Henoch-Schönlein purpura.


Assuntos
Autoanticorpos/sangue , Vasculite por IgA/imunologia , Glomérulos Renais/imunologia , Trombomodulina/sangue , Adolescente , Animais , Biomarcadores/sangue , Bovinos , Técnicas de Cultura de Células , Criança , Pré-Escolar , Citotoxicidade Imunológica , Endotélio/citologia , Endotélio/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Vasculite por IgA/patologia , Imunoglobulina G/sangue , Masculino , Solubilidade
20.
Proc Natl Acad Sci U S A ; 94(9): 4378-82, 1997 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-9113997

RESUMO

Although muscle contraction is known to result from movement of the myosin heads on the thick filaments while attached to the thin filaments, the myosin head movement coupled with ATP hydrolysis still remains to be investigated. Using a gas environmental (hydration) chamber, in which biological specimens can be kept in wet state, we succeeded in recording images of living muscle thick filaments with gold position markers attached to the myosin heads. The position of individual myosin heads did not change appreciably with time in the absence of ATP, indicating stability of the myosin head mean position. On application of ATP, the position of individual myosin heads was found to move by approximately 20 nm along the filament axis, whereas no appreciable movement of the filaments was detected. The ATP-induced myosin head movement was not observed in filaments in which ATPase activity of the myosin heads was eliminated. Application of ADP produced no appreciable myosin head movement. These results show that the ATP-induced myosin head movement takes place in the absence of the thin filaments. Because ATP reacts rapidly with the myosin head (M) to form the complex (M. ADP.Pi) with an average lifetime of >10 s, the observed myosin head movement may be mostly associated with reaction, M + ATP --> M.ADP. Pi. This work will open a new research field to study dynamic structural changes of individual biomolecules, which are kept in a living state in an electron microscope.


Assuntos
Citoesqueleto de Actina/fisiologia , Trifosfato de Adenosina/farmacologia , Movimento/fisiologia , Miosinas/fisiologia , Tropomiosina/fisiologia , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/ultraestrutura , Animais , Coloide de Ouro , Microscopia Eletrônica/métodos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Miosinas/efeitos dos fármacos , Miosinas/ultraestrutura , Coelhos , Tropomiosina/efeitos dos fármacos , Tropomiosina/ultraestrutura
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