Design of a rapid, multiplex, one-pot miRNA assay optimized by label-free analysis.

MicroRNAs are widely studied as circulating biomarkers for early stage diagnosis of several diseases. Detection and quantification of miRNAs is currently performed through complex and time consuming procedures. Herein we demonstrate a rapid, multiplex, one-pot detection method based on two-step amplification of the signal measured by Reflective Phantom Interface (RPI) label-free optical biosensor. We achieved sub-pM quantification of different miRNAs in about 1.5 h, through specific capture with surface DNA probes combined to a 35-fold mass amplification by an antibody targeting DNA-RNA hybrids and polyclonal secondary antibody, all performed without washing steps. The assay is the result of a modelling and optimization of the multi-step process that has been made possible by the RPI characterization of each individual interaction involved.

Co-administration of H-ferritin-doxorubicin and Trastuzumab in neoadjuvant setting improves efficacy and prevents cardiotoxicity in HER2 + murine breast cancer model.

Neoadjuvant chemotherapy has been established as the standard of care for HER2-positive breast cancer since it allows cancer down-staging, up to pathological complete response. The standard of care in the neoadjuvant setting for HER2-positive breast cancer is a combination of highly cytotoxic drugs such as anthracyclines and the anti-HER2 monoclonal antibody. Despite this cocktail allows a pathological complete response in up to 50%, their co-administration is strongly limited by intrinsic cardiotoxicity. Therefore, only a sequential administration of anthracyclines and the anti-HER2 treatment is allowed. Here, we propose the anthracycline formulation in H-Ferritin nanocages as promising candidate to solve this unmet clinical need, thanks to its capability to increase anthracyclines efficacy while reducing their cardiotoxicity. Treating a murine model of HER2-positive breast cancer with co-administration of Trastuzumab and H-Ferritin anthracycline nanoformulation, we demonstrate an improved tumor penetration of drugs, leading to increased anticancer efficacy and reduced of cardiotoxicity.

Laser writing of nanostructured silicon arrays for the SERS detection of biomolecules with inhibited oxidation.

The present work reports the processing of laser irradiated Si arrays (LISi) and underlines their surface enhanced Raman scattering (SERS) functionality. A nanostructured Si/SiOx surface forms providing additional fluidic and photoprotective properties. Because of their optical and surface characteristics, the arrays exhibit a SERS analytical enhancing factor of 500, without any noble metals such as gold or silver. Micro-Raman maps allowed studying LISi properties, identifying maximum amplification in nanostructured areas characterized by the presence of 7 nm Si nanocrystals. These structures are confined by a SiOx layer as illustrated by XPS valence band measurements. The highly hydrophilic LISi areas allow a pre-concentration of target molecules prior to SERS analysis. A relevant application of LISi was found in the detection of apomorphine (APO), a drug used for the treatment of Parkinson's disease. In contrast with what is obtained by using gold SERS substrates, LISi allows the detection of APO with no sign of oxidation. This invites for the use of the Si/SiOx SERS detection in future systems for the personalized delivery of APO.

Label-free imaging and identification of typical cells of acute myeloid leukaemia and myelodysplastic syndrome by Raman microspectroscopy.

In clinical practice, the diagnosis and classification of acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) start from the manual examination of stained smears of bone marrow (BM) and peripheral blood (PB) by using an optical microscope. This step is subjective and scarcely reproducible. Therefore, the development of subjective and potentially automatable methods for the recognition of typical AML/MDS cells is necessary. Here we have used Raman spectroscopy for distinguishing myeloblasts, promyelocytes, abnormal promyelocytes and erhytroblasts, which have to be counted for a correct diagnosis and morphological classification of AML and MDS. BM samples from patients affected by four different AML subtypes, mostly characterized by the presence of the four subpopulations selected for this study, were analyzed. First, each cell was scanned by acquiring 4096 spectra, thus obtaining Raman images which demonstrate an accurate description of morphological features characteristic of each subpopulation. Raman imaging coupled with hierarchical cluster analysis permitted the automatic discrimination and localization of the nucleus, the cytoplasm, myeloperoxidase containing granules and haemoglobin. Second, the averaged Raman fingerprint of each cell was analysed by multivariate analysis (principal component analysis and linear discriminant analysis) in order to study the typical vibrational features of each subpopulation and also for the automatic recognition of cells. The leave-one-out cross validation of a Raman-based classification model demonstrated the correct classification of myeloblasts, promyelocytes (normal/abnormal) and erhytroblasts with an accuracy of 100%. Normal and abnormal promyelocytes were distinguished with 95% accuracy. The overall classification accuracy considering the four subpopulations was 98%. This proof-of-concept study shows that Raman micro-spectroscopy could be a valid approach for developing label-free, objective and automatic methods for the morphological classification and counting of cells from AML/MDS patients, in substitution of the manual examination of BM and PB stained smears.

Subcortical anarthria: a case report.

A 56-year-old right-handed male with a history of hypertension and diabetes presented two episodes of stroke: The first affected territory was the left anterior coroidal artery (capsular and paracapsular infarcts at the level of the genu and posterior arm of the internal capsule) and the second was the right thalamus, due to a hematoma. Following the first stroke, the patient developed severe dysarthria and after the second stroke remained anarthric. The pathophysiology of the disorder is discussed, and the role of the left and right thalamus as far as speech is concerned is reviewed.

Ritmo circadiano y accidente cerebrovascular / Stroke and circadian rhythm

La variación diaria en la aparición de Accidente Cerebro Vascular (ACV) fue examinada en 255 pacientes. Estos incluyeron 173 isquemias y 82 hemorragias intraparenquimatosas (HI). Los pacientes fueron ordenados en despiertos y dormidos, y distribuidos en 4 períodos de 6 horas cada uno. La frecuencia de aparición de ACV isquémico fue significativa (p<0,001) para el período de 08 a 14 horas (46,6%); para las HI también fue significativa (p<0,001) para el mismo período (46,3%). Se analizaron otras variables: edad, sexo y tipo de lesión relacionándolas con el estado del paciente (despierto-dormido) y con el momento (día-noche) en que ocurrió el ACV. El análisis de los pacientes con ACV isquémico y hemorrágico con manifestación al despertar mostró una frecuencia significativa (p<0,001) para las isquemias (81,3%) que para las HI (18,7%)

Epilepsia gelástica / Gelastic epilepsy

Con motivo de la publicación de un caso en el cual la risa involuntaria e inmotivada constituye la única manifestación clínica de Epilepsia en la edad adulta, se hace una revisión histórica del problema, se discute la fisiología de la risa normal, se enmarca la Epilepsia Gelástica en el contexto de la risa patológica y se comentan múltiples etiologías, diversas localizaciones lesionales y un espectro de patrones clínicos y electroencefalográficos en relación con Epilepsia Gelástica

Hipotensión ortostática, disautonomia y signos neurologicos centrales / Orthostatic hypotension, dysautonomia and central neurologic signs

Se presenta el caso de una mujer de 68 años afectada de hipotensión ortostática, disfunción pupilar, sudoral y vesical, y respuestas hemodinámicas anormales a la maniobra de Valsalva, además de signos piramidales, extrapiramidales, disartria y amiotrofias distales, compatible con atrofia multisistémica (AMS), discutiendo la relación de este cuadro con la enfermedad o síndrome de Shy y Drager, del cual parece tratarse de una variante un tanto atípica por: 1) La ausencia de signos cerebelosos, 2) La preservación de respuestas parasimpáticas y 3) La rareza de los hallazgos neuroquímicos.

Creutzfeldt-Jakob disease. Report of 10 neuropathologically-verified cases in Argentina.

We describe 10 neuropathologically verified patients with Creutzfeldt-Jakob disease who died in Argentina between 1980 and 1987. Two of the ten cases were Chilean by birth. Another case visited Chile several times. Two cases (one Argentinian and one Chilean) regularly consumed sheep brain. Ages ranged from 42 to 63 years and the male to female ratio was 7:3. Disease duration ranged from 3.5 to 24 months. Prodromal symptoms presented as behavioral changes in 5 patients, lasting from one year to several weeks, and as neurological impairment in the other 5. Patients developed pyramidal, extrapyramidal and cerebellar disturbances, as well as movement disorders and progressive dementia. Visual alterations were found in 5 cases and periodic EEG activity in 7. Unequivocal cortical spongiform changes, together with varying degrees of neuronal depletion and astroglial hyperplasia were constant findings. No white matter involvement was apparent either from CT brain scans or on histopathological study of biopsied and autopsied material. Increasing awareness of this disease as well as possibilities of transmission is necessary in order to provide better information on its true incidence in Argentina.

Creutzfeldt-Jakob disease: report of 10 neuropathologically verified cases in Argentina

Enfermedad de Creutzfeldt-Jakob. Comunicación de 10 casos en Argentina con verificación neuropatológica. La incidencia mundial de la enfermedad de Creutzfeldt-Jakob (CJ) es dealrededor de un caso por millón de población por año. A pesar de nuestra proximidad con Chile, donde la incidencia es alta, las comunicaciones en nuestro medio alcanzan a 9 casos desde 1945 a 1980. Se presenta una serie de 10 casos de CJ con confirmación neuropatológica por biopsia cerebral y/o autopsia, nueve de ellos estudiados a partir de la creación de un Centro Neuropatológico Nacional de Referencia de Enfermedades por "virus lentos". El rango de edad de los pacientes fue de 42 a 63 años, correspondiendo la mitad de los casos a la 6ta. década. La distribución por sexo fue de 3 mujeres y 7 varones. La duración de la enfermedad fue de 3,5 a 24 meses, con una media de 10,4 meses. Todos los casos fueron esporádicos (el caso 2 tenía antecendentes neurológicos paternos poco claros). Ocho de los diez pacientes eran argentinos, los otros dos eran chilenos de nacimiento, que emigraron a la Argentina 26 años previos al comienzo de los síntomas (caso 9) y 6 meses antes de su fallecimiento (caso6). El caso 7 visitó Chile periódicamente. De los 8 argentinos, 5 eran residentes de Buenos Aires, Capital, y 3 de Córdoba, Rosario y Mar del Plata. Los casos 6 y 9 presentaban como antecendente de interés la ingestión, con relativa frecuencia, de cerebro de oveja. Los síntomas prodrómicos consistieron esencialmente en trastornos...