Detection of Pulmonary Shunts by Transcranial Doppler in Hospitalized Non-mechanically Ventilated Coronavirus Disease-19 Patients.

In severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated disease coronavirus disease 2019 (COVID-19), hypoxemia mechanisms differ from those observed in acute respiratory distress syndrome. Hypoxemia and respiratory failure in COVID- 19 are attributed to pulmonary angiopathy, increasing physiological pulmonary shunting1-3.

Adult-Onset White Matter Vanishing Disease With Ovarian Failure in a Salvadoran Patient.

White matter vanishing disease is a type of leukodystrophy common in children with hypomyelination linked with ataxia, all of whom have an autosomal recessive inheritance. There are few reports of late-onset cases associated with ovarian failure. In Mesoamerican populations, this disease is mostly reported in children but rarely in adults. We present a case of a 35-year-old Salvadoran female patient with a history of menometrorrhagia, infertility, slowly progressive gait decline, paraparesis, spasticity, cerebellar ataxia, cognitive impairment with predominant executive dysfunction, learning difficulties, and emotional lability. A T2-weighted brain MRI and fluid-attenuated inversion recovery (FLAIR) images showed bilateral symmetrical areas of hyperintensities in the white matter with multiple foci of cystic degeneration within the hyperintense area. Two pathogenic variants were identified in the EIF2B5 gene. This case is of interest to increase awareness of late-onset leukodystrophies, widen the phenotypic spectrum of the disease, and constitute a valuable report for the international community, since it is a less frequently reported disease.

Pourfour Du Petit Syndrome Due to Ipsilateral Internal Jugular Vein Distention.

Pourfour du Petit Syndrome (PdPS) is characterized by signs of oculosympathetic hyperactivity caused by irritation in the oculosympathetic pathway and shares etiologies with Horner Syndrome. We present the case of a 64-year-old woman with Pourfour du Petit syndrome due to compression of the second-order cervical sympathetic chain neuron from a dominant and prominent right internal jugular vein compensatory for contralateral agenesis. Internal jugular vein agenesis is a rare developmental vascular anomaly and is asymptomatic in the majority of patients with this condition.

Influence of HRGO Nanoplatelets on Behaviour and Processing of PMMA Bone Cement for Surgery.

Bone cement, frequently based on poly (methyl methacrylate), is commonly used in different arthroplasty surgical procedures and its use is essential for prosthesis fixation. However, its manufacturing process reaches high temperatures (up to 120 °C), producing necrosis in the patients' surrounding tissues. To help avoid this problem, the addition of graphene could delay the polymerisation of the methyl methacrylate as it could, simultaneously, favour the optimisation of the composite material's properties. In this work, we address the effect of different percentages of highly reduced graphene oxide with different wt.% (0.10, 0.50, and 1.00) and surface densities (150, 300, 500, and 750 m2/g) on the physical, mechanical, and thermal properties of commercial poly (methyl methacrylate)-based bone cement and its processing. It was noted that a lower sintering temperature was achieved with this addition, making it less harmful to use in surgery and reducing its adverse effects. In contrast, the variation of the density of the materials did not introduce significant changes, which indicates that the addition of highly reduced graphene oxide would not significantly increase bone porosity. Lastly, the mechanical properties (strength, elastic modulus, and fracture toughness) were reduced by almost 20%. Nevertheless, their typical values are high enough that these new materials could still fulfil their structural function. In conclusion, this paper presents a way to control the sintering temperature, without significant degradation of the mechanical performance, by adding highly reduced graphene oxide so that local necrosis of bone cement based on poly (methyl methacrylate) used in surgery is avoided.

Self-Healing Polymer Nanocomposite Materials by Joule Effect.

Nowadays, the self-healing approach in materials science mainly relies on functionalized polymers used as matrices in nanocomposites. Through different physicochemical pathways and stimuli, these materials can undergo self-repairing mechanisms that represent a great advantage to prolonging materials service-life, thus avoiding early disposal. Particularly, the use of the Joule effect as an external stimulus for self-healing in conductive nanocomposites is under-reported in the literature. However, it is of particular importance because it incorporates nanofillers with tunable features thus producing multifunctional materials. The aim of this review is the comprehensive analysis of conductive polymer nanocomposites presenting reversible dynamic bonds and their energetical activation to perform self-healing through the Joule effect.

Agraphia: Presenting Feature of Syndrome of Transient Headache and Neurological Deficits With Cerebrospinal Fluid Lymphocytosis (HaNDL).

We report a case of a 48-year-old man with a history of episodes of severe headache, accompanied by motor aphasia and agraphia, with complete recovery between episodes. The neurological examination revealed no abnormality. A lumbar puncture was performed and showed lymphocytic pleocytosis. Cerebrospinal fluid analysis ruled out viral, bacterial, mycobacterial, fungal, treponemal, and NMDA receptor antibodies. Brain magnetic resonance imaging and electroencephalogram revealed no abnormalities. A focal frontotemporal area of hypoperfusion was detected in brain single-photon emission tomography. A diagnosis of syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) was made to the patient and then treated with ibuprofen 400 mg three times per day with excellent response. He remained asymptomatic and free of any relapse during six months of following. We presented a typical case of HaNDL that manifests with agraphia, a transient focal neurological deficit non previously reported. Showing that the clinical picture could probably be any sign and symptom related to focal cortical alteration due to cortical transient hypoperfusion.

Evaluación del blanqueamiento dentario de piezas teñidas con tetraciclina utilizando peróxido de carbamida al 10 por ciento con carbopol a largo plazo / A long-term evaluation of bleaching tetracycline-stained teeth using 10 per cent carbamide peroxide with carbopol

Las tinciones de los dientes por tetraciclina corresponden a una patología de tinción dentaria intrínseca adquirida, difícil de tratar por métodos no conservadores. El objeto de este estudio fue la aplicación de un blanqueamiento extendido con peróxido de carbamida al 10 por ciento con carbopol (Opalescence) con una cubeta individual de blanqueamiento nocturno por 4 horas diarias por 16 semanas, para verificar diferencias y la eficacia de este tratamiento en controles a las 8 y 16 semanas. Se seleccionaron 4 pacientes con sus dientes anterosuperiores teñidos con el antibiótico (24 dientes en total) que cumplieran requisitos específicos de salud y que aceptaran realizarse un tratamiento extendido sólo del maxilar superior. Se realizaron controles clínicos y fotográficos a las 2, 4, 8, 12 y 16 semanas. Para la muestra en cuestión, no se encontraron diferencias significativas en la cantidad de grises (o valor) entre los controles 0 y 8 semanas (mayor blanqueamiento dentario). Asimismo, se encontró un mayor grado de blanqueamiento entre 0 y 16 semanas y entre 8 y 16 semanas de control. El 100 por ciento de los pacientes presentó sensibilidad en los primeros controles no se evidenciaron cambios en el sabor e irritación gingival. Se concluye que el blanqueamiento extendido de dientes teñidos por tetraciclina logra un éxito para la muestra revisada, pero se requieren mayores estudios acerca de la regresión de las tinciones en el tiempo