RESUMO
Scanning electron microscopy is a technique that provides high-resolution images at the micro- and nano-scale. The combination of scanning electron microscopy and energy dispersive X-ray spectroscopy analysis is developing fast for application in forensic science. In this work, we report a case of work-related traumatic death of a 50-year-old man. The autopsy showed cranial fractures with cerebral haemorrhage. It was more difficult to understand the accident dynamics because the body had been shifted from the accident site to mask what had really taken place. Scanning electron microscopy/energy dispersive X-ray spectroscopy was used to identify the material of the impacting tool and to establish the possible legal responsibility of the employer. In this study, we demonstrate that scanning electron microscopy/energy dispersive X-ray spectroscopy is a useful forensic tool for the analysis of biological samples. Further, for studying the lacerations on the corpse from doubtful blunt tools, scanning electron microscopy/energy dispersive X-ray spectroscopy can assist in demonstrating that the scene has been falsified, as it was in this case.
Assuntos
Traumatismos Craniocerebrais/diagnóstico por imagem , Traumatismos Ocupacionais/diagnóstico por imagem , Autopsia/instrumentação , Autopsia/métodos , Traumatismos Craniocerebrais/mortalidade , Traumatismos Craniocerebrais/patologia , Medicina Legal/métodos , Humanos , Masculino , Microscopia Eletrônica de Varredura/métodos , Pessoa de Meia-Idade , Traumatismos Ocupacionais/mortalidade , Traumatismos Ocupacionais/patologia , Espectrometria por Raios X/métodos , Ferimentos não Penetrantes/complicações , Ferimentos não Penetrantes/diagnóstico por imagem , Ferimentos não Penetrantes/patologiaRESUMO
Secretome of primary cultures is an accessible source of biological markers compared to more complex and less decipherable mixtures such as serum or plasma. The protonation state (PS) of secretome reflects the metabolism of cells and can be used for cancer early detection. Here, we demonstrate a superhydrophobic organic electrochemical device that measures PS in a drop of secretome derived from liquid biopsies. Using data from the sensor and principal component analysis (PCA), we developed algorithms able to efficiently discriminate tumour patients from non-tumour patients. We then validated the results using mass spectrometry and biochemical analysis of samples. For the 36 patients across three independent cohorts, the method identified tumour patients with high sensitivity and identification as high as 100% (no false positives) with declared subjects at-risk, for sporadic cancer onset, by intermediate values of PS. This assay could impact on cancer risk management, individual's diagnosis and/or help clarify risk in healthy populations.
RESUMO
Biopolymers are increasingly employed for neuroscience applications as scaffolds to drive and promote neural regrowth, thanks to their ability to mediate the upload and subsequent release of active molecules and drugs. Synthetic degradable polymers are characterized by different responses ranging from tunable distension or shrinkage to total dissolution, depending on the function they are designed for. In this paper we present a biocompatible microfabricated poly-ε-caprolactone (PCL) scaffold for primary neuron growth and maturation that has been optimized for the in vitro controlled release of brain-derived neurotrophic factor (BDNF). We demonstrate that the designed morphology confers to these devices an enhanced drug delivery capability with respect to monolithic unstructured supports. After incubation with BDNF, micropillared PCL devices progressively release the neurotrophin over 21 days in vitro. Moreover, the bioactivity of released BDNF is confirmed using primary neuronal cultures, where it mediates a consistent activation of BDNF signaling cascades, increased synaptic density, and neuronal survival. These results provide the proof-of-principle on the fabrication process of micropatterned PCL devices, which represent a promising therapeutic option to enhance neuronal regeneration after lesion and for neural tissue engineering and prosthetics.
Assuntos
Materiais Biocompatíveis/química , Fator Neurotrófico Derivado do Encéfalo/administração & dosagem , Sistemas de Liberação de Medicamentos , Regeneração Nervosa , Tecido Nervoso/fisiologia , Polímeros/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Astrócitos/citologia , Astrócitos/ultraestrutura , Biomarcadores/metabolismo , Adesão Celular , Sobrevivência Celular , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Camundongos Endogâmicos C57BL , Neurônios/citologia , Neurônios/ultraestrutura , Poliésteres/química , Transdução de Sinais , Sinapses/metabolismoRESUMO
Advances in carbohydrate sequencing technologies reveal the tremendous complexity of the glycome and the role that glycomics might have to bring insight into the biological functions. Carbohydrate-protein interactions, in particular, are known to be crucial to most mammalian physiological processes as mediators of cell adhesion and metastasis, signal transducers, and organizers of protein interactions. An assay is developed here to mimic the multivalency of biological complexes that selectively and sensitively detect carbohydrate-protein interactions. The binding of ß-galactosides and galectin-3--a protein that is correlated to the progress of tumor and metastasis--is examined. The efficiency of the assay is related to the expression of the receptor while anchoring to the interaction's strength. Comparative binding experiments reveal molecular binding preferences. This study establishes that the assay is robust to isolate metastatic cells from colon affected patients and paves the way to personalized medicine.
Assuntos
Carboidratos , Microfluídica/métodos , Proteínas/metabolismo , Adesão Celular/fisiologia , Linhagem Celular , Galactosídeos/química , Galectina 3/química , Células HCT116 , Humanos , Ligação ProteicaRESUMO
Optofluidic microsystems are key components towards lab-on-a-chip devices for manipulation and analysis of biological specimens. In particular, the integration of optical tweezers (OT) in these devices allows stable sample trapping, while making available mechanical, chemical and spectroscopic analyses.