RESUMEN
Acoustic levitation has attracted attention in terms of chemical and biochemical analysis in combination with various analytical methods because of its unique container-less environment for samples that is not reliant on specific material characteristics. However, loading samples with very high viscosity is difficult. To expand the scope, we propose the use of polymer thin films as sample holders, whereby the sample is dispensed on a film that is subsequently loaded onto an acoustic levitator. When applied for protein crystallography experiments, rotation controllability and positional stability are important prerequisites. We therefore study the acoustic levitation and rotation of thin films with an aspect ratio (the diameter-to-thickness ratio) of 80-240, which is an order of magnitude larger than those reported previously. For films with empirically optimized shapes, we find that it is possible to control the rotation speed in the range of 1-4 rotations per second while maintaining a positional stability of 12 ± 5 µm. The acoustic radiation force acting on the films is found to be a factor of 26-30 higher than that for same-volume water droplets. We propose use cases of the developed films for protein crystallography experiments and demonstrate data collections for large single crystal samples at room temperature.
Asunto(s)
Acústica , Proteínas , Cristalografía , Temperatura , Agua/químicaRESUMEN
Human skin, not previously frozen, was studied by small-angle X-ray diffraction. The samples were folded so that a 6µm X-ray beam passed through the top layer of skin, stratum corneum. Diffraction patterns recorded with this method consisted of peaks at about q = 0.5, 1.0 and 1.4 nm-1 in the direction perpendicular to the skin surface more clearly than in previous studies. These peaks are interpreted to arise from lipids between corneocytes. A simple unit of a linear electron density profile with three minima was used to account for the observed intensity profiles. Combinations of calculated diffraction from models with one, two and three units accounted for the major part of the observed diffraction pattern, showing the diversity in the structure of the intercellular lipids.
Asunto(s)
Epidermis/química , Lípidos/química , Dispersión del Ángulo Pequeño , Difracción de Rayos X , Adulto , Femenino , Humanos , Persona de Mediana EdadRESUMEN
Many neurodegenerative diseases are characterized by the accumulation of abnormal protein aggregates in the brain. In Parkinson's disease (PD), α-synuclein (α-syn) forms such aggregates called Lewy bodies (LBs). Recently, it has been reported that aggregates of α-syn with a cross-ß structure are capable of propagating within the brain in a prionlike manner. However, the presence of cross-ß sheet-rich aggregates in LBs has not been experimentally demonstrated so far. Here, we examined LBs in thin sections of autopsy brains of patients with PD using microbeam X-ray diffraction (XRD) and found that some of them gave a diffraction pattern typical of a cross-ß structure. This result confirms that LBs in the brain of PD patients contain amyloid fibrils with a cross-ß structure and supports the validity of in vitro propagation experiments using artificially formed amyloid fibrils of α-syn. Notably, our finding supports the concept that PD is a type of amyloidosis, a disease featuring the accumulation of amyloid fibrils of α-syn.
Asunto(s)
Amiloide/metabolismo , Amiloidosis/metabolismo , Enfermedad de Parkinson/etiología , Enfermedad de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Amiloide/química , Amiloidosis/patología , Animales , Encéfalo/metabolismo , Encéfalo/patología , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Humanos , Cuerpos de Lewy/metabolismo , Ratones , Enfermedad de Parkinson/patología , Placa Amiloide/metabolismo , Placa Amiloide/patología , Difracción de Rayos XRESUMEN
Herein we report the case of a 10-year-old boy with an autosomal mosaic mutation who developed bacteremia. The causative agent was identified as Moraxella osloensis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene sequencing. In the pediatric population, there have been 13 case reports of infection attributed to M. osloensis and this is the fifth reported case of pediatric bacteremia due to M. osloensis. After Moraxella species infection was confirmed, the patient recovered with appropriate antimicrobial therapy. It is important to consider that M. osloensis can cause serious infections, such as bacteremia, in otherwise healthy children.
Asunto(s)
Bacteriemia/microbiología , Moraxella/aislamiento & purificación , Infecciones por Moraxellaceae/microbiología , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Niño , Humanos , Masculino , Infecciones por Moraxellaceae/tratamiento farmacológico , Reacción en Cadena de la Polimerasa , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Resultado del TratamientoRESUMEN
ABSTRACT Herein we report the case of a 10-year-old boy with an autosomal mosaic mutation who developed bacteremia. The causative agent was identified as Moraxella osloensis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene sequencing. In the pediatric population, there have been 13 case reports of infection attributed to M. osloensis and this is the fifth reported case of pediatric bacteremia due to M. osloensis. After Moraxella species infection was confirmed, the patient recovered with appropriate antimicrobial therapy. It is important to consider that M. osloensis can cause serious infections, such as bacteremia, in otherwise healthy children.
Asunto(s)
Humanos , Masculino , Niño , Bacteriemia/microbiología , Infecciones por Moraxellaceae/microbiología , Moraxella/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Resultado del Tratamiento , Bacteriemia/tratamiento farmacológico , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Infecciones por Moraxellaceae/tratamiento farmacológico , Antibacterianos/uso terapéuticoRESUMEN
Monosomy 1p36 is a common subtelomeric microdeletion syndrome, characterized by craniofacial dysmorphisms, developmental delay, mental retardation, hypotonia, epilepsy, cardiovascular complications, and hearing impairment; deleted regions have been mapped within 10.0 Mb from the telomere in most documented cases. We report on a girl with a 10.5-11.1 Mb terminal deletion of 1p36 shown by fluorescence in situ hybridization (FISH). She had three distinct structural abnormalities: bilateral perisylvian polymicrogyria, periventricular nodular heterotopia, and left ventricular noncompaction. She died in early infancy with intractable epilepsy, progressive congestive heart failure and pulmonary hypertension. To date, this is the first case with monosomy 1p36, complicated by this combination of manifestations; she is also the first who had possibly a simple terminal deletion of 1p36 and died in early infancy. An atypically large deletion in this patient might be the basis for the development of these features and the severe clinical course.