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

RESUMEN

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.


Asunto(s)
Formularios de Consentimiento , Consentimiento Informado , Comprensión , Odontología , Humanos , España
3.
Arch. Soc. Esp. Oftalmol ; 94(12): 619-621, dic. 2019. ilus
Artículo en Español | IBECS | ID: ibc-190016

RESUMEN

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


Asunto(s)
Humanos , Femenino , Adulto , Lesiones Oculares Penetrantes/diagnóstico por imagen , Transferrina/análisis , Humor Acuoso , Biomarcadores/análisis , Rinorrea de Líquido Cefalorraquídeo/diagnóstico por imagen , Reacciones Falso Positivas , Fístula/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Hemorragia Vítrea/etiología
4.
Arch Soc Esp Oftalmol (Engl Ed) ; 94(12): 619-621, 2019 Dec.
Artículo en Inglés, Español | MEDLINE | ID: mdl-31311689

RESUMEN

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.


Asunto(s)
Lesiones Oculares Penetrantes/diagnóstico por imagen , Transferrina/análisis , Adulto , Humor Acuoso , Biomarcadores/análisis , Rinorrea de Líquido Cefalorraquídeo/diagnóstico por imagen , Reacciones Falso Positivas , Femenino , Fístula/diagnóstico por imagen , Humanos , Tomografía Computarizada por Rayos X , Hemorragia Vítrea/etiología
5.
Cell Death Dis ; 6: e1763, 2015 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-25973683

RESUMEN

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.


Asunto(s)
Proteínas de Unión al ADN/genética , Estrés del Retículo Endoplásmico/efectos de los fármacos , Gentamicinas/farmacología , Pérdida Auditiva de Alta Frecuencia , Ácido Tauroquenodesoxicólico/farmacología , Factores de Transcripción/genética , Animales , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Línea Celular , Proteínas de Unión al ADN/metabolismo , Retículo Endoplásmico/patología , Femenino , Células HEK293 , Células Ciliadas Auditivas/patología , Pérdida Auditiva de Alta Frecuencia/inducido químicamente , Pérdida Auditiva de Alta Frecuencia/genética , Pérdida Auditiva de Alta Frecuencia/patología , Humanos , Masculino , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos CBA , Neuronas/patología , Biosíntesis de Proteínas/efectos de los fármacos , Pliegue de Proteína , Deficiencias en la Proteostasis , Empalme del ARN/genética , Factores de Transcripción del Factor Regulador X , Ganglio Espiral de la Cóclea/citología , Ganglio Espiral de la Cóclea/efectos de los fármacos , Ganglio Espiral de la Cóclea/patología , Factores de Transcripción/metabolismo , Respuesta de Proteína Desplegada/genética , Respuesta de Proteína Desplegada/fisiología , Proteína 1 de Unión a la X-Box
6.
Neuroimage ; 36(4): 1301-12, 2007 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-17524671

RESUMEN

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.


Asunto(s)
Nivel de Alerta/fisiología , Corteza Cerebral/irrigación sanguínea , Electroencefalografía , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Actividad Motora/fisiología , Tomografía de Emisión de Positrones , Procesamiento de Señales Asistido por Computador , Transmisión Sináptica/fisiología , Adulto , Mapeo Encefálico , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/fisiología , Dominancia Cerebral/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Motora/irrigación sanguínea , Corteza Motora/diagnóstico por imagen , Corteza Motora/fisiología , Red Nerviosa/irrigación sanguínea , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiología , Neuronas/fisiología , Lóbulo Occipital/irrigación sanguínea , Lóbulo Occipital/diagnóstico por imagen , Lóbulo Occipital/fisiología , Corteza Prefrontal/irrigación sanguínea , Corteza Prefrontal/diagnóstico por imagen , Corteza Prefrontal/fisiología , Valores de Referencia , Flujo Sanguíneo Regional/fisiología , Corteza Somatosensorial/irrigación sanguínea , Corteza Somatosensorial/diagnóstico por imagen , Corteza Somatosensorial/fisiología , Estadística como Asunto
7.
Neurology ; 65(11): 1708-15, 2005 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-16344511

RESUMEN

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.


Asunto(s)
Encéfalo/irrigación sanguínea , Encéfalo/fisiopatología , Circulación Cerebrovascular/fisiología , Alucinaciones/fisiopatología , Enfermedad de Parkinson/fisiopatología , Anciano , Encéfalo/diagnóstico por imagen , Femenino , Alucinaciones/diagnóstico por imagen , Alucinaciones/etiología , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/diagnóstico por imagen , Valor Predictivo de las Pruebas , Lóbulo Temporal/irrigación sanguínea , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/fisiopatología , Tomografía Computarizada de Emisión de Fotón Único , Corteza Visual/irrigación sanguínea , Corteza Visual/diagnóstico por imagen , Corteza Visual/fisiopatología , Vías Visuales/irrigación sanguínea , Vías Visuales/diagnóstico por imagen , Vías Visuales/fisiopatología , Percepción Visual/fisiología
9.
Br J Ophthalmol ; 86(12): 1363-6, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12446366

RESUMEN

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.


Asunto(s)
Aldehído Reductasa/análisis , Diabetes Mellitus Tipo 2/enzimología , Retinopatía Diabética/enzimología , Eritrocitos/enzimología , Adulto , Factores de Edad , Biomarcadores/análisis , Estudios Transversales , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Retinopatía Diabética/sangre , Retinopatía Diabética/complicaciones , Ensayo de Inmunoadsorción Enzimática , Femenino , Hemoglobina A/análisis , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo
10.
Fukuoka Igaku Zasshi ; 92(5): 167-76, 2001 May.
Artículo en Japonés | MEDLINE | ID: mdl-11452514

RESUMEN

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.


Asunto(s)
Hígado/metabolismo , Bifenilos Policlorados/metabolismo , Animales , Cricetinae , Cromatografía de Gases y Espectrometría de Masas , Cobayas , Masculino , Ratas , Ratas Wistar , Especificidad de la Especie , Análisis Espectral
11.
Biochem Biophys Res Commun ; 285(4): 1007-11, 2001 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-11467852

RESUMEN

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.


Asunto(s)
Neuronas/fisiología , Fotones , Animales , Células Cultivadas , Cerebelo/citología , Luz , Masculino , Red Nerviosa/fisiología , Neuronas/citología , Oxidación-Reducción , Estrés Oxidativo/fisiología , Fenilhidrazinas/farmacología , Fotometría/instrumentación , Ratas , Transmisión Sináptica/fisiología
12.
Cancer Gene Ther ; 8(4): 285-93, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11393281

RESUMEN

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.


Asunto(s)
Proteínas de Unión al ADN/genética , Herpesvirus Humano 8/genética , ARN Catalítico/farmacología , Factores de Transcripción/genética , Animales , Secuencia de Bases , Proteínas de Unión al ADN/metabolismo , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Células HeLa/efectos de los fármacos , Células HeLa/metabolismo , Células HeLa/virología , Humanos , Técnicas In Vitro , Factores Reguladores del Interferón , Ratones , Datos de Secuencia Molecular , Sistemas de Lectura Abierta/genética , ARN Mensajero/metabolismo , Factores de Transcripción/metabolismo , Transfección , Proteínas Virales
13.
FEBS Lett ; 474(1): 16-22, 2000 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-10828443

RESUMEN

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.


Asunto(s)
Dictyostelium/química , Factores de Intercambio de Guanina Nucleótido/química , Miosinas/química , Proteínas Protozoarias , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Calmodulina/metabolismo , Dictyostelium/genética , Dictyostelium/ultraestructura , Proteínas Fluorescentes Verdes , Humanos , Indicadores y Reactivos , Proteínas Luminiscentes , Datos de Secuencia Molecular , Miosinas/análisis , Miosinas/genética , Filogenia , Factores de Intercambio de Guanina Nucleótido Rho , Alineación de Secuencia
14.
Jpn J Ophthalmol ; 44(2): 132-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10715379

RESUMEN

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.


Asunto(s)
Córnea/patología , Refracción Ocular , Desprendimiento de Retina/cirugía , Perforaciones de la Retina/cirugía , Curvatura de la Esclerótica , Astigmatismo/etiología , Astigmatismo/fisiopatología , Humanos , Complicaciones Posoperatorias , Periodo Posoperatorio , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento
15.
Nihon Rinsho ; 57 Suppl: 172-5, 1999 Sep.
Artículo en Japonés | MEDLINE | ID: mdl-10543080

Asunto(s)
Biotina/sangre , Humanos
16.
Fukuoka Igaku Zasshi ; 90(5): 220-30, 1999 May.
Artículo en Japonés | MEDLINE | ID: mdl-10396878

RESUMEN

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.


Asunto(s)
Contaminantes Ambientales/metabolismo , Microsomas Hepáticos/metabolismo , Bifenilos Policlorados/metabolismo , Animales , Células Cultivadas , Cricetinae , Sistema Enzimático del Citocromo P-450/metabolismo , Cobayas , Humanos , Hidroxilación , Isoenzimas/metabolismo , Masculino , Microsomas Hepáticos/enzimología , Ratas , Ratas Wistar , Especificidad de la Especie
17.
Biochem Biophys Res Commun ; 261(2): 276-82, 1999 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-10425178

RESUMEN

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.


Asunto(s)
Mutación , Subfragmentos de Miosina/química , Subfragmentos de Miosina/genética , Silicatos de Aluminio , Secuencia de Aminoácidos , Animales , Biofisica/instrumentación , Dictyostelium/genética , Elasticidad , Contracción Muscular/fisiología , Ingeniería de Proteínas , Conejos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Plata , Propiedades de Superficie
19.
Arch Dis Child ; 78(3): 240-4, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9613354

RESUMEN

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.


Asunto(s)
Autoanticuerpos/sangre , Vasculitis por IgA/inmunología , Glomérulos Renales/inmunología , Trombomodulina/sangre , Adolescente , Animales , Biomarcadores/sangre , Bovinos , Técnicas de Cultivo de Célula , Niño , Preescolar , Citotoxicidad Inmunológica , Endotelio/citología , Endotelio/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Vasculitis por IgA/patología , Inmunoglobulina G/sangre , Masculino , Solubilidad
20.
Proc Natl Acad Sci U S A ; 94(9): 4378-82, 1997 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-9113997

RESUMEN

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.


Asunto(s)
Citoesqueleto de Actina/fisiología , Adenosina Trifosfato/farmacología , Movimiento/fisiología , Miosinas/fisiología , Tropomiosina/fisiología , Citoesqueleto de Actina/efectos de los fármacos , Citoesqueleto de Actina/ultraestructura , Animales , Oro Coloide , Microscopía Electrónica/métodos , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Miosinas/efectos de los fármacos , Miosinas/ultraestructura , Conejos , Tropomiosina/efectos de los fármacos , Tropomiosina/ultraestructura
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