RESUMEN
We successfully performed electron scattering off unstable nuclei which were produced online from the photofission of uranium. The target ^{137}Cs ions were trapped with a new target-forming technique that makes a high-density stationary target from a small number of ions by confining them in an electron storage ring. After developments of target generation and transportation systems and the beam stacking method to increase the ion beam intensity up to approximately 2×10^{7} ions per pulse beam, an average luminosity of 0.9×10^{26} cm^{-2} s^{-1} was achieved for ^{137}Cs. The obtained angular distribution of elastically scattered electrons is consistent with a calculation. This success marks the realization of the anticipated femtoscope which clarifies the structures of exotic and short-lived unstable nuclei.
RESUMEN
The chemical properties of an element are primarily governed by the configuration of electrons in the valence shell. Relativistic effects influence the electronic structure of heavy elements in the sixth row of the periodic table, and these effects increase dramatically in the seventh row--including the actinides--even affecting ground-state configurations. Atomic s and p1/2 orbitals are stabilized by relativistic effects, whereas p3/2, d and f orbitals are destabilized, so that ground-state configurations of heavy elements may differ from those of lighter elements in the same group. The first ionization potential (IP1) is a measure of the energy required to remove one valence electron from a neutral atom, and is an atomic property that reflects the outermost electronic configuration. Precise and accurate experimental determination of IP1 gives information on the binding energy of valence electrons, and also, therefore, on the degree of relativistic stabilization. However, such measurements are hampered by the difficulty in obtaining the heaviest elements on scales of more than one atom at a time. Here we report that the experimentally obtained IP1 of the heaviest actinide, lawrencium (Lr, atomic number 103), is 4.96(+0.08)(-0.07) electronvolts. The IP1 of Lr was measured with (256)Lr (half-life 27 seconds) using an efficient surface ion-source and a radioisotope detection system coupled to a mass separator. The measured IP1 is in excellent agreement with the value of 4.963(15) electronvolts predicted here by state-of-the-art relativistic calculations. The present work provides a reliable benchmark for theoretical calculations and also opens the way for IP1 measurements of superheavy elements (that is, transactinides) on an atom-at-a-time scale.
RESUMEN
We observed the atomic 1s and 2p states of π^{-} bound to ^{121}Sn nuclei as distinct peak structures in the missing mass spectra of the ^{122}Sn(d,^{3}He) nuclear reaction. A very intense deuteron beam and a spectrometer with a large angular acceptance let us achieve a potential of discovery, which includes the capability of determining the angle-dependent cross sections with high statistics. The 2p state in a Sn nucleus was observed for the first time. The binding energies and widths of the pionic states are determined and found to be consistent with previous experimental results of other Sn isotopes. The spectrum is measured at finite reaction angles for the first time. The formation cross sections at the reaction angles between 0° and 2° are determined. The observed reaction-angle dependence of each state is reproduced by theoretical calculations. However, the quantitative comparison with our high-precision data reveals a significant discrepancy between the measured and calculated formation cross sections of the pionic 1s state.
RESUMEN
The first elastic electron scattering has been successfully performed at the self-confining radioactive-isotope ion target (SCRIT) facility, the world's first electron scattering facility for SCRIT technique achieved high luminosity (over 10^{27} cm^{-2} s^{-1}, sufficient for determining the nuclear shape) with only 10^{8} target ions. While ^{132}Xe used in this time as a target is a stable isotope, the charge density distribution was first extracted from the momentum transfer distributions of the scattered electrons by comparing the results with those calculated by a phase shift calculation.
RESUMEN
Fission-fragment mass distributions were measured for ^{237-240}U, ^{239-242}Np, and ^{241-244}Pu populated in the excitation-energy range from 10 to 60 MeV by multinucleon transfer channels in the reaction ^{18}O+^{238}U at the Japan Atomic Energy Agency tandem facility. Among them, the data for ^{240}U and ^{240,241,242}Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multichance fission.
RESUMEN
At the Mainz Microtron MAMI, the first high-resolution pion spectroscopy from decays of strange systems was performed by electron scattering off a (9)Be target in order to study the Λ binding energy of light hypernuclei. Positively charged kaons were detected by a short-orbit spectrometer with a broad momentum acceptance at 0° forward angles with respect to the beam, efficiently tagging the production of strangeness in the target nucleus. Coincidentally, negatively charged decay pions were detected by two independent high-resolution spectrometers. About 10(3) pionic weak decays of hyperfragments and hyperons were observed. The pion momentum distribution shows a monochromatic peak at pπ≈133 MeV/c, corresponding to the unique signature for the two-body decay of hyperhydrogen Λ(4)Hâ(4)He+π(-), stopped inside the target. Its Λ binding energy was determined to be BΛ=2.12±0.01 (stat)±0.09 (syst)MeV with respect to the (3)H+Λ mass.
RESUMEN
Tenascin-C (Tn-C) is an extracellular matrix glycoprotein implicated in the progression of several human cancers. In canine mammary carcinomas, accumulation of Tn-C has been recognized in 3 different areas: regions of proliferating myoepithelial cells in complex carcinoma, basement membrane zone in low-grade simple carcinoma, and reactive stroma in high-grade simple carcinoma. To identify the Tn-C synthesizing cells in these areas, we utilized double-labeling immunohistochemistry, branched DNA in situ hybridization, and in situ hybridization-immunohistochemistry double-labeling techniques. In complex carcinomas, Tn-C was generated by proliferating myoepithelial cells. Tn-C in low-grade simple carcinomas was also derived from myoepithelial cells existing as a basal monolayer. However, stromal Tn-C in high-grade carcinomas was mainly synthesized by fibroblasts/myofibroblasts, similar to human breast cancer. Thus, the origin of Tn-C in canine mammary carcinomas differs between low- and high-grade malignancies. The role of myoepithelial cell-generated Tn-C is not yet understood.
Asunto(s)
Enfermedades de los Perros/patología , Neoplasias Mamarias Animales/patología , Animales , Progresión de la Enfermedad , Enfermedades de los Perros/metabolismo , Perros , Células Epiteliales/metabolismo , Células Epiteliales/patología , Femenino , Fibroblastos/metabolismo , Fibroblastos/patología , Hibridación in Situ/veterinaria , Neoplasias Mamarias Animales/metabolismo , Miofibroblastos/metabolismo , Miofibroblastos/patología , Tenascina/metabolismoRESUMEN
Mammary tumors that spontaneously occurred in domestic Djungarian hamsters (Phodopus sungorus) were histologically examined. Forty-five mammary tumors included 14 adenomas, 18 adenocarcinomas, 1 lipid-rich carcinoma, 2 adenoacanthomas, 2 malignant adenomyoepitheliomas, 1 benign mixed tumor, and 7 "balloon cell" carcinosarcomas. The latter 4 types were newly recognized neoplasms in Djungarian hamsters. The relatively high incidence of spontaneous mammary carcinosarcomas in domestic Djungarian hamsters is intriguing. Carcinosarcomas exhibited anomalous histological features made up of a mixture of glandular cells, polygonal cells (including "balloon cells"), and sarcomatous spindle cells in varying proportions. Transitional features from glandular cells to polygonal cells and subsequently to sarcomatous spindle cells were observed. Using immunohistochemistry, we observed that glandular cells exhibited an epithelial phenotype (cytokeratin(+)/vimentin(-)), spindle cells exhibited a mesenchymal phenotype (cytokeratin(-)/vimentin(+)), and polygonal cells exhibited an intermediate phenotype (cytokeratin(+)/vimentin(+)). Reduction or loss of ß-catenin expression and gain of S100A4 expression were observed in polygonal and spindle cells. The polygonal cell population included a varying number of characteristic cells that were expanded by large intracytoplasmic vacuoles. Electron microscopy revealed that these "balloon cells" had large cytoplasmic lumens lined by microvilli. These observations suggest that epithelial-mesenchymal transition may account for the pathogenesis of mammary carcinosarcomas in Djungarian hamsters.
Asunto(s)
Adenocarcinoma/veterinaria , Carcinoma/veterinaria , Neoplasias Mamarias Animales/patología , Phodopus , Enfermedades de los Roedores/patología , Adenocarcinoma/patología , Animales , Carcinoma/patología , Cricetinae , Transición Epitelial-Mesenquimal , Femenino , Inmunohistoquímica/veterinaria , Queratinas/análisis , Vimentina/análisis , beta Catenina/análisisRESUMEN
The low affinity neurotrophin receptor p75NTR is known to be expressed in the mitotically quiescent basal layer (BL) of the normal esophageal epithelium. The aim of the present study was to detect oncogenic changes in the p75NTR-positive BL during esophageal squamous carcinogenesis. The normal epithelium (NE), low-grade intraepithelial neoplasia (LGN), high-grade intraepithelial neoplasia (HGN), and esophageal squamous carcinoma (SCC), in which invasion was limited to the muscularis mucosa, were obtained from surgically removed esophagi. The expression of p75NTR, the proliferation marker ki67, hTERT, p53, and p63 was examined immunohistochemically. The expression of p75NTR was detected in these tissues with average staining indexes (number of stained cells/100 nucleated cells; SI) of 1.00, 0.99, 0.81, and 0.73, respectively. The expression of ki67 in the BL significantly increased with the progression from LGN to HGN. The expression of hTERT and p53 significantly increased with the progression from NE to LGN, and then increased in a stepwise manner in HGN and SCC, with SI (hTERT/p53) of 0.10/0.11, 0.32/0.45, 0.50/0.72, and 0.65/0.61, respectively. The expression of p63 showed no significant difference among NE, LGN, HGN, and SCC, with SI of 0.82, 0.77, 0.85, and 0.87, respectively. A correlation was observed between the expression of ki67 and p53 (P = 0.005), while a negative correlation was found between p75NTR and hTERT (P = 0.01). Our results demonstrated that phenotypic changes from quiescent to active proliferation in the p75NTR-positive BL occurred during the progression from LGN to HGN. The altered expression of hTERT and p53 in the BL was detected in LGN, which suggested that additional oncogenic events that disrupt mitotic regulation in the p75NTR-positive quiescent BL may play a crucial role in malignant transformation. Further investigations using the isolation and tracing of p75NTR-positive cells in precancerous epithelia may provide us with a better understanding of squamous carcinogenesis.
Asunto(s)
Carcinogénesis/metabolismo , Carcinoma de Células Escamosas/metabolismo , Proliferación Celular , Neoplasias Esofágicas/metabolismo , Esófago/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Receptores de Factor de Crecimiento Nervioso/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/patología , Epitelio/metabolismo , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago , Esofagectomía , Esófago/patología , Humanos , Inmunohistoquímica , Antígeno Ki-67/metabolismo , Proteínas de la Membrana/metabolismo , Telomerasa/metabolismo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Routinely diagnosed simple solid carcinoma (SSC) of the canine mammary gland comprises a heterogeneous group of tumors. Seventy-two cases that had been diagnosed as SSC based on hematoxylin and eosin-stained tissue sections were reclassified immunohistochemically on the basis of myoepithelial markers p63 and α-smooth muscle actin, as well as a luminal epithelial marker cytokeratin 8. Only 23 cases (32%) were true SSC, composed only of luminal epithelial cells, whereas 11 cases (15%) were malignant myoepithelioma (MM), composed predominantly of myoepithelial cells, and 38 cases (53%) were biphasic carcinoma (BC), characterized by biphasic proliferation of luminal epithelial and basal/myoepithelial components. As the pathological parameters were compared between the reclassified tumor types, infiltrative potential, vascular/lymphatic invasion, lymph node metastasis, and Ki-67 labeling index were higher in true SSC compared with MM and BC, suggesting that the former may exhibit a poorer prognosis compared with the latter two.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Carcinoma/veterinaria , Enfermedades de los Perros/patología , Neoplasias Mamarias Animales/patología , Mioepitelioma/veterinaria , Animales , Carcinoma/metabolismo , Carcinoma/patología , Enfermedades de los Perros/metabolismo , Perros , Células Epiteliales/patología , Femenino , Inmunohistoquímica/veterinaria , Metástasis Linfática , Neoplasias Mamarias Animales/metabolismo , Mioepitelioma/metabolismo , Mioepitelioma/patologíaRESUMEN
Data related to radioactivity released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 15 March 2011 gathered by residents of Miharu, Fukushima Prefecture, and by Tohoku University are presented. These data sets consist of (1) the earliest radiation monitoring by a Geiger counter in the town, (2) ratios of radioactivity between (132)Te and (137)Cs for a wide area between Fukushima and Tokyo, (3) radiation measurement of soil samples collected from 18 school grounds, and (4) external radiation exposure of 1400 students using OSL badges. By combining and analysing these various data sets, a curve for the cumulative total external exposure as a function of time, with 16 : 00 h on 15 March 2011 being time zero, is obtained. The average cumulative external dosage is estimated to be 10 mSv (σ = 4.2 mSv) over 10 years. In addition, the initiative that the residents of Miharu took in response to the FDNPP accident, which became known as The Misho Project (MP), is documented; in particular, the time at which the municipality instructed the immediate ingestion of iodine tablets by those under the age of 40, 13 : 00 h on 15 March 2011, is assessed.
Asunto(s)
Accidente Nuclear de Fukushima , Plantas de Energía Nuclear , Radiación Ionizante , Radiometría/estadística & datos numéricos , JapónRESUMEN
BACKGROUND/PURPOSE: Aquaporins (AQPs) are important in controlling bile formation. However, the exact role in human gallbladder carcinogenesis has not yet been defined. METHODS: AQP-5-expressing gallbladder carcinoma (GBC) cell lines (NOZ) were transfected with anti-AQP-5 small interfering RNA (siRNA). Growth, migration, invasion assay, and drug susceptibility tests were performed. Next, microRNA (miRNA) expression was analyzed by miRNA oligo chip (3D-Gene®). AQP-5 and AQP-5-related miRNA target gene expressions were also analyzed using tissue microarray (TMA) in 44 GBC samples. RESULTS: Treatment with AQP-5 siRNA decreased cell proliferation, migration, and invasion. On the other hand, those cells increased IC50 of gemcitabine. By performing miRNA assays, miR-29b, -200a, and -21 were shown to be highly overexpressed in cells treated with AQP-5 siRNA NOZ. When focusing on miR-21, phosphatase and tensin homolog (PTEN) was found to be a target of miR-21. In the TMA, AQP-5/PTEN coexpression was significantly associated with the depth of invasion and MIB-1 index (p = 0.003, 0.010). Survival of patients with a high AQP-5/PTEN coexpression was longer than that of patients with a low coexpression (p = 0.003). CONCLUSIONS: Our result suggested that miR-21 and PTEN may contribute to the role of AQP-5 in GBC. AQP-5 and PTEN cascades are favorable biomarkers of GBC.
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Acuaporina 5/fisiología , Neoplasias de la Vesícula Biliar/etiología , Adulto , Anciano , Acuaporina 5/genética , Línea Celular Tumoral , Movimiento Celular , Femenino , Neoplasias de la Vesícula Biliar/genética , Neoplasias de la Vesícula Biliar/mortalidad , Neoplasias de la Vesícula Biliar/patología , Humanos , Masculino , MicroARNs/análisis , Persona de Mediana Edad , Invasividad Neoplásica , Fosfohidrolasa PTEN/análisis , Fosfohidrolasa PTEN/fisiología , ARN Mensajero/análisis , Análisis de Matrices TisularesRESUMEN
Ring chromosome 14 (r14) is clinically characterized by early-onset epilepsy, mental retardation, delayed speech, microcephaly, extremely mild facial dysmorphisms and ophthalmologic abnormalities. We report a case presenting with partial seizures and delayed development in infancy in which r14 was diagnosed based on chromosomal analysis. The patient was a girl with a normal family and delivery history. Afebrile generalized convulsions developed at age 9 months, and phenobarbital was started, but was changed to zonisamide due to impaired liver function. Chromosome analysis led to a diagnosis of 46, XX, r(14) (p11.2q32.3). At age 5 years, while under treatment with zonisamide and clobazam, epilepsy was characterized by multiple daily episodes of complex partial seizures. Although there are no consistent brain MRI or electroencephalogram findings, experienced pediatric neurologists can make a diagnosis based on facial dysmorphisms. When refractory epilepsy is encountered in infancy with developmental delay of unknown cause, chromosome analysis should be performed.
Asunto(s)
Trastornos de los Cromosomas/diagnóstico , Discapacidades del Desarrollo/diagnóstico , Epilepsias Parciales/diagnóstico , Anticonvulsivantes/uso terapéutico , Benzodiazepinas/uso terapéutico , Preescolar , Trastornos de los Cromosomas/genética , Cromosomas Humanos Par 14/genética , Clobazam , Discapacidades del Desarrollo/genética , Epilepsias Parciales/tratamiento farmacológico , Epilepsias Parciales/genética , Femenino , Humanos , Lactante , Isoxazoles/uso terapéutico , Fenobarbital/uso terapéutico , Cromosomas en Anillo , Síndrome , ZonisamidaRESUMEN
Maternal virilization in pregnancy with or without fetal female pseudohermaphroditism has several etiologies. Of these, pregnancy luteoma is the most common cause of maternal virilization during pregnancy, and approximately 20 cases have been reported in recent years. Moreover, four cases of pregnancy luteomas with female pseudohermaphroditism have been reported. However, the extremely rare steroid cell tumor, not otherwise specified (NOS), has been reported only once as a cause for maternal virilization. Herein, the authors report the first case of maternal virilization with female pseudohermaphroditism associated with steroid cell tumor-NOS along with the clinical course, pathological features, and a review of the literature.
Asunto(s)
Trastornos del Desarrollo Sexual 46, XX/etiología , Neoplasias Ováricas/complicaciones , Complicaciones Neoplásicas del Embarazo , Virilismo/complicaciones , Virilismo/diagnóstico , Trastornos del Desarrollo Sexual 46, XX/complicaciones , Adulto , Neoplasias Cerebelosas/complicaciones , Neoplasias Cerebelosas/patología , Neoplasias Cerebelosas/cirugía , Cesárea , Trastornos del Desarrollo Sexual , Femenino , Edad Gestacional , Humanos , Recien Nacido Prematuro , Luteoma/complicaciones , Imagen por Resonancia Magnética , Meduloblastoma/complicaciones , Meduloblastoma/patología , Meduloblastoma/cirugía , Neoplasias Ováricas/patología , Neoplasias Ováricas/cirugía , Embarazo , Testosterona/sangreRESUMEN
OBJECTIVE: The aim of this study was to evaluate the effects of the Assertive Community Treatment (ACT) program in a Japanese mental health service setting. METHOD: This study was a randomized controlled trial. ACT was the intervention condition (n = 59), and the usual hospital-based rehabilitation program was the control condition (n = 59). Outcome indicators include in-patient days, psychiatric symptoms, social functioning, quality of life, and client satisfaction. The follow-up period was 12 months after the intervention. RESULTS: We found a significant reduction of in-patient days for the ACT group demonstrated by t-test (t = 2.33, P = 0.02). However, the results of ancova did not show significant differences for in-patient days between the two groups (F = 1.85, P = 0.18). The depression score for Brief Psychiatric Rating Scale for the ACT group was significantly lower than the control group at the 12-month follow-up assessment (F = 5.57, P = 0.03). According to the t-test, the ACT group had a higher client satisfaction than the control group (t = 2.08, P = 0.05). CONCLUSION: We concluded that ACT had a positive influence, as evidenced by a reduction of in-patient days, lower depressive symptoms, and higher client satisfaction.
Asunto(s)
Actividades Cotidianas , Servicios Comunitarios de Salud Mental/normas , Depresión/terapia , Inteligencia Emocional , Trastornos Mentales/terapia , Satisfacción del Paciente , Adolescente , Adulto , Escalas de Valoración Psiquiátrica Breve , Femenino , Humanos , Japón , Masculino , Trastornos Mentales/psicología , Servicios de Salud Mental , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
The aims of this study were to determine whether the appearance of stromal myofibroblasts and the expression of tenascin-C (Tn-C) correlate with the grade of malignancy in canine mammary tumors and to determine the main cellular source of Tn-C in these tumors. Single or double immunostaining using antibodies against α-smooth muscle actin (α-SMA) and Tn-C was performed on serial sections of normal canine mammary glands as well as those with lobular hyperplasia, simple adenoma, and simple carcinoma. Thirty-nine of 42 simple carcinomas (93%) exhibited stromal α-SMA-positive myofibroblasts and Tn-C expression. Only 6 of 11 cases of simple adenoma (55%) showed these changes, whereas no changes were observed in normal mammary gland tissue or cases of lobular hyperplasia. The distribution of stromal Tn-C correlated with the presence of myofibroblasts. However, Tn-C immunoreactivity was also occasionally observed in the basement membrane zone surrounding the myoepithelial layer in normal tissue, benign lesions, and tubulopapillary carcinomas. This pattern of staining was not related to the presence of myofibroblasts. The appearance of stromal myofibroblasts and expression of Tn-C were significantly correlated with higher histological grades of malignancy and vascular/lymphatic invasion in simple carcinomas. Stromal myofibroblasts appear to be a major cellular source of Tn-C and play an important role in the development of canine mammary tumors. The Tn-C expressed in the basement membrane zone of normal, hyperplastic, and neoplastic mammary tissue, which is likely produced by neighboring myoepithelial cells, may differ functionally from the Tn-C produced by myofibroblasts.
Asunto(s)
Enfermedades de los Perros/patología , Neoplasias Mamarias Animales/patología , Miofibroblastos/citología , Tenascina/metabolismo , Animales , Proliferación Celular , Perros , Femenino , Regulación Neoplásica de la Expresión Génica/fisiología , Neoplasias Mamarias Animales/clasificación , Neoplasias Mamarias Animales/metabolismoRESUMEN
GJB2 is the gene most frequently associated with hereditary hearing loss, and the GJB2 mutation spectrums vary among different ethnic groups. In this study, the mutation spectrum as well as clinical features of patients with GJB2 mutations as found in more than 1000 Japanese hearing loss families are summarized. The present results show that the frequency of GJB2 mutations in the Japanese population with hearing loss is 14.2% overall and 25.2% in patients with congenital hearing loss. c.235delC was the most frequent allele (49.8%), was associated with a more severe phenotype, and was mainly found in patients who were diagnosed by the age of 3. In contrast, the second most frequent was p.V37I (16.5%), which has a milder phenotype and was mainly found in patients diagnosed at a higher age. Additional clinical features in hearing loss patients with GJB2 mutations in this study were the near absence of tinnitus, vestibular dysfunction and inner ear malformations.
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Conexinas/genética , Pérdida Auditiva/genética , Pueblo Asiatico/genética , Audiometría , Niño , Preescolar , Estudios de Cohortes , Conexina 26 , Frecuencia de los Genes , Pérdida Auditiva/congénito , Pérdida Auditiva Sensorineural/genética , Humanos , Lactante , MutaciónRESUMEN
Boron Neutron Capture Therapy (BNCT) is a radiotherapy for the treatment of intractable cancer. In BNCT precise determination of 10B concentration in whole blood sample before neutron irradiation of the patient, as well as accurate neutron dosimetry, is crucial for control of the neutron irradiation time. For this purpose ICP-AES and neutron induced prompt γ-ray analysis are generally used. In Ibaraki Neutron Medical Research Center (iNMRC), an intense proton beam will be accelerated up to 8 MeV, which can also be used for Charged Particle Activation Analysis (CPAA). Thus, in this study, we apply the CPAA utilizing the proton beam to non-destructive and accurate determination of 10B concentration in whole blood sample. A CPAA experiment is performed by utilizing an 8 MeV proton beam from the tandem accelerator of Nuclear Science Research Institute in Japan Atomic Energy Agency. The 478 keV γ-ray of 7Be produced by the 10B(p, α)7Be reaction is used to quantify the 10B in human blood. The 478 keV γ-ray intensity is normalized by the intensities of the 847 keV and 1238 keV γ-rays of 56Co originating from Fe in blood. The normalization methods were found to be linear in the range of 3.27 µg 10B/g to 322 µg 10B/g with correlation coefficients of better than 0.9999.
Asunto(s)
Boro/sangre , Boro/normas , Terapia por Captura de Neutrón de Boro/métodos , Calibración , Rayos gamma , Humanos , Espectrometría de Masas/métodos , Radiometría/métodos , Dosificación Radioterapéutica , Estándares de Referencia , Reproducibilidad de los Resultados , IncertidumbreRESUMEN
The mitochondrial 1555A>G mutation is one of the most common mutations responsible for hearing loss in Asians. Although the association with aminoglycoside exposure is well known, there is great variation in the severity of hearing loss. We analyzed hearing levels in 221 Japanese individuals with this mutation and attempted to identify relevant covariants including (i) age, (ii) aminoglycoside exposure, (iii) heteroplasmy ratio, and (iv) other gene mutations. At every age, average hearing levels were worse than those in normal subjects, suggesting that mitochondrial function itself may affect the severity of hearing loss. Although the hearing loss in individuals with the 1555A>G mutation progressed with age, the rate did not differ from that of the normal subjects. Those who had reported aminoglycoside exposure had moderate-to-severe hearing impairment regardless of age, confirming that such exposure is the most important environmental variable. We also confirmed the presence of heteroplasmy, which is known to modify the expression of other mitochondrial diseases, but found no evidence for a significant correlation with hearing impairment. A high prevalence of GJB2 heterozygous mutations was noted, indicating that these mutations may exhibit epistatic interaction with the 1555A>G mutation.
Asunto(s)
ADN Mitocondrial/química , Pérdida Auditiva/genética , Mutación Puntual , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Conexina 26 , Conexinas , Audición/genética , Pérdida Auditiva Sensorineural/genética , Heterocigoto , Humanos , Persona de Mediana Edad , PrevalenciaRESUMEN
We have measured the branching ratio of the three-body process in the nonmesonic weak decay of Lambda12C to be 0.29+/-0.13. This result was obtained by reproducing the nucleon and the nucleon pair yields introducing a measured final state interaction. At the same time, we have determined the absolute decay widths, Gamma(n) and Gamma(p), along with Gamma2N, whose relative ratio has been a long-standing puzzle. Including the three-body process, we have successfully reproduced the nucleon energy distribution, the coincidence two-nucleon angular correlation, and the momentum sum distribution simultaneously.