Enfermedad de Creutzfeld Jakob, desafío diagnóstico : reporte de dos casos en la ciudad de Mendoza

La enfermedad de Creutzfeldt-Jakob (ECJ) es una afección neurodege-nerativa rápidamente progresiva y mortal producida por priones. Es la más común de las encefalopatías espongiformes. La hipótesis prevalente sugiere que se inicia y propaga por conversión de una proteína priónica normal (PrP) en una isoforma conformacional anormal (PrPreS), que se acumula en el cerebro causando destrucción neuronal. Se reporta el caso de dos pacientes asistido en el Servicio de Neurología del Hospital Lagomaggiore de la ciudad de Mendoza en el período de 2 años: mujer de 49 años con cuadro de deterioro cognitivo rápidamente progresivo asociado a trastorno de la marcha y ataxia de 2 meses de evolución; y varón de 54 años con conductas inapropiadas y desorientación temporo-espacial de 20 días de evolución. Ambos con EEG compatible y proteína 14.3.3 positiva, falleciendo semanas después del diagnóstico. Se discute ambos casos, los cuales representaron un desafío diagnóstico dada la baja frecuencia y escaso reconocimiento de esta entidad en nuestro medio, debiendo debe ser considerado en pacientes que evolucionan a una demencia rápidamente progresiva.Creutzfeldt-Jakob disease (CJD) is a rapidly progressive and fatal neurodegenerative disease caused by prions. It is the most common of spongiform encephalopathies. The most accepted hypothesis suggests that it initiates and propagates through conversion of normal prion protein (PrP) in an abnormal conformational isoform (PrPres), which accumulates in the brain causing neuronal destruction. The cases of two patients assisted in the Department of Neurology of Hospital Lagomaggiore city of Mendoza in 2-year period are reported: A 49-year old female patient with symptoms of rapidly progressing cognitive impairment associated with gait disturbance and ataxia of 2 months of progression; and a 54-year old male with misconduct and temporo-spatial disorientation of 20 days of evolution. In both cases, EEG was compatible with CJD and 14.3.3 protein was positive, dying weeks after diagnosis. Both cases are discussed, which represented a diagnostic challenge given the low frequency and little recognition of this entity in our environment, must be considered in patients who develop a rapidly progressive dementia.Fil: Galiana, Graciana Lourdes. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: Farfan Alé, F.. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: De Monte, M.. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: Sánchez, C.. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: Torres, A.. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: Ianardi, S.. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: Genco, J.. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: Genco, D.. Hospital Luis Lagomaggiore (Mendoza, Argentina)Fil: Castellino, G.. Hospital Luis Lagomaggiore (Mendoza, Argentina

The (C-H) bond dissociation energy in the methyl group of toluene

A, kinetic study of the pyrolysis of toluene by a flow technique has been made, and assuming Szwarc\u27s mechanism, two activation energies (78.3 and 84 kcal/mole depending on the temperature range used) have been derived for the dissociation of the (C-H) bond in the methyl group of toluene. The lower value agrees quite well with Szwarc\u27s, and the higher value turns out to be approximately the average of 77.5 and 89.9. The results of this research suggest 84 kcal/mole as the upper limit for the activation energy

High-throughput multimodal wide-field Fourier-transform Raman microscope

Raman microscopy is a powerful analytical technique for materials and life sciences that enables mapping the spatial distribution of the chemical composition of a sample. State-of-the-art Raman microscopes, based on point-scanning frequency-domain detection, have long (∼1 s) pixel dwell times, making it challenging to acquire images of a significant area (e.g., 100×100 μm). Here we present a compact wide-field Raman microscope based on a time-domain Fourier-transform approach, which enables parallel acquisition of the Raman spectra on all pixels of a 2D detector. A common-path birefringent interferometer with exceptional delay stability and reproducibility can rapidly acquire Raman maps (∼30 min for a 250 000 pixel image) with high spatial (<1 μm) and spectral (∼23 cm-1) resolutions. Time-domain detection allows us to disentangle fluorescence and Raman signals, which can both be measured separately. We validate the system by Raman imaging plastic microbeads and demonstrate its multimodal operation by capturing fluorescence and Raman maps of a multilayer-WSe2 sample, providing complementary information on the strain and number of layers of the material

Adjustable Intragastric Balloons: A 12-Month Pilot Trial in Endoscopic Weight Loss Management

Intragastric balloons are associated with (1) early period intolerance, (2) diminished effect within 3–4 months, and (3) bowel obstruction risk mandating removal at 6 months. The introduction of an adjustable balloon could improve comfort and offer greater efficacy. A migration prevention function, safely enabling prolonged implantation, could improve efficacy and weight maintenance post-extraction. The first implantations of an adjustable balloon with an attached migration prevention anchor are reported. The primary endpoint was the absence of bowel perforation, obstruction, or hemorrhage. Eighteen patients with mean BMI of 37.3 were implanted with the Spatz Adjustable Balloon system (ABS) for 12 months. Balloon volumes were adjusted for intolerance or weight loss plateau. Mean weight loss at 24 weeks was 15.6 kg with 26.4% EWL (percent of excess weight loss) and 24.4 kg with 48.8% EWL at 52 weeks. Sixteen adjustments were successfully performed. Six downward adjustments alleviated intolerance, yielding additional mean weight loss of 4.6 kg. Ten upward adjustments for weight loss plateau yielded a mean additional weight loss of 7 kg. Seven balloons were removed prematurely. Complications necessitating early removal included valve malfunction (1), gastritis (1), Mallory–Weiss tear (1), NSAID (2× dose/2 weeks) perforating ulcer (1), and balloon deflation (1). Two incidents of catheter shear from the chain: one passed uneventfully and one caused an esophageal laceration without perforation during extraction. The Spatz ABS has been successfully implanted in 18 patients. (1) Upward adjustments yielded additional weight loss. (2) Downward adjustments alleviated intolerance, with continued weight loss. (3) Preliminary 1-year implantation results are encouraging

Electrically pumped WSe2-based light-emitting van der Waals heterostructures embedded in monolithic dielectric microcavities

Vertical stacking of atomically thin layered materials opens new possibilities for the fabrication of heterostructures with favorable optoelectronic properties. The combination of graphene, hexagonal boron nitride and semiconducting transition metal dichalcogenides allows fabrication of electroluminescence (EL) devices, compatible with a wide range of substrates. Here, we demonstrate a full integration of an electroluminescent van der Waals heterostructure in a monolithic optical microcavity made of two high reflectivity dielectric distributed Bragg reflectors (DBRs). Owing to the presence of graphene and hexagonal boron nitride protecting the WSe2 during the top mirror deposition, we fully preserve the optoelectronic behaviour of the device. Two bright cavity modes appear in the EL spectrum featuring Q-factors of 250 and 580 respectively: the first is attributed directly to the monolayer area, while the second is ascribed to the portion of emission guided outside the WSe2 island. By embedding the EL device inside the microcavity structure, a significant modification of the directionality of the emitted light is achieved, with the peak intensity increasing by nearly two orders of magnitude at the angle of the maximum emission compared with the same EL device without the top DBR. Furthermore, the coupling of the WSe2 EL to the cavity mode with a dispersion allows a tuning of the peak emission wavelength exceeding 35 nm (80 meV) by varying the angle at which the EL is observed from the microcavity. This work provides a route for the development of compact vertical-cavity surface-emitting devices based on van der Waals heterostructures

The effect of periodontal therapy on lymphocyte blastogenesis to plaque associated microorganisms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66105/1/j.1600-0765.1983.tb00340.x.pd

Ground deformation reveals the scale-invariant conduit dynamics driving explosive basaltic eruptions

The mild activity of basaltic volcanoes is punctuated by violent explosive eruptions that occur without obvious precursors. Modelling the source processes of these sudden blasts is challenging. Here, we use two decades of ground deformation (tilt) records from Stromboli volcano to shed light, with unprecedented detail, on the short-term (minute-scale) conduit processes that drive such violent volcanic eruptions. We find that explosive eruptions, with source parameters spanning seven orders of magnitude, all share a common pre-blast ground inflation trend. We explain this exponential inflation using a model in which pressure build-up is caused by the rapid expansion of volatile-rich magma rising from depth into a shallow (<400m) resident magma conduit. We show that the duration and amplitude of this inflation trend scales with the eruption magnitude, indicating that the explosive dynamics obey the same (scale-invariant) conduit process. This scale-invariance of pre-explosion ground deformation may usher in a new era of short-term eruption forecasting

Ground deformation reveals the scale-invariant conduit dynamics driving explosive basaltic eruptions

The mild activity of basaltic volcanoes is punctuated by violent explosive eruptions that occur without obvious precursors. Modelling the source processes of these sudden blasts is challenging. Here, we use two decades of ground deformation (tilt) records from Stromboli volcano to shed light, with unprecedented detail, on the short-term (minute-scale) conduit processes that drive such violent volcanic eruptions. We find that explosive eruptions, with source parameters spanning seven orders of magnitude, all share a common pre-blast ground inflation trend. We explain this exponential inflation using a model in which pressure build-up is caused by the rapid expansion of volatile-rich magma rising from depth into a shallow (<400 m) resident magma conduit. We show that the duration and amplitude of this inflation trend scales with the eruption magnitude, indicating that the explosive dynamics obey the same (scale-invariant) conduit process. This scale-invariance of pre-explosion ground deformation may usher in a new era of short-term eruption forecasting

A Single-Molecule Bioelectronic Portable Array for Early Diagnosis of Pancreatic Cancer Precursors

A cohort of 47 patients is screened for pancreatic cancer precursors with a portable 96-well bioelectronic sensing-array for single-molecule assay in cysts fluid and blood plasma, deployable at point-of-care (POC). Pancreatic cancer precursors are mucinous cysts diagnosed with a sensitivity of at most 80% by state-of-the-art cytopathological molecular analyses (e.g., KRASmut DNA). Adding the simultaneous assay of proteins related to malignant transformation (e.g., MUC1 and CD55) is deemed essential to enhance diagnostic accuracy. The bioelectronic array proposed here, based on single-molecule-with-a-large-transistor (SiMoT) technology, can assay both nucleic acids and proteins at the single-molecule limit-of-identification (LOI) (1% of false-positives and false-negatives). It comprises an enzyme-linked immunosorbent assay (ELISA)-like 8 × 12-array organic-electronics disposable cartridge with an electrolyte-gated organic transistor sensor array, and a reusable reader, integrating a custom Si-IC chip, operating via software installed on a USB-connected smart device. The cartridge is complemented by a 3D-printed sensing gate cover plate. KRASmut, MUC1, and CD55 biomarkers either in plasma or cysts-fluid from 5 to 6 patients at a time, are multiplexed at single-molecule LOI in 1.5 h. The pancreatic cancer precursors are classified via a machine-learning analysis resulting in at least 96% diagnostic-sensitivity and 100% diagnostic-specificity. This preliminary study opens the way to POC liquid-biopsy-based early diagnosis of pancreatic-cancer precursors in plasma