Improved Automatic Segmentation of White Matter Hyperintensities in MRI Based on Multilevel Lesion Features.

Brain white matter hyperintensities (WMHs) are linked to increased risk of cerebrovascular and neurodegenerative diseases among the elderly. Consequently, detection and characterization of WMHs are of significant clinical importance. We propose a novel approach for WMH segmentation from multi-contrast MRI where both voxel-based and lesion-based information are used to improve overall performance in both volume-oriented and object-oriented metrics. Our segmentation method (AMOS-2D) consists of four stages following a "generate-and-test" approach: pre-processing, Gaussian white matter (WM) modelling, hierarchical multi-threshold WMH segmentation and object-based WMH filtering using support vector machines. Data from 28 subjects was used in this study covering a wide range of lesion loads. Volumetric T1-weighted images and 2D fluid attenuated inversion recovery (FLAIR) images were used as basis for the WM model and lesion masks defined manually in each subject by experts were used for training and evaluating the proposed method. The method obtained an average agreement (in terms of the Dice similarity coefficient, DSC) with experts equivalent to inter-expert agreement both in terms of WMH number (DSC = 0.637 vs. 0.651) and volume (DSC = 0.743 vs. 0.781). It allowed higher accuracy in detecting WMH compared to alternative methods tested and was further found to be insensitive to WMH lesion burden. Good agreement with expert annotations combined with stable performance largely independent of lesion burden suggests that AMOS-2D will be a valuable tool for fully automated WMH segmentation in patients with cerebrovascular and neurodegenerative pathologies.

The effect of five proteins on stem cells used for osteoblast differentiation and proliferation: a current review of the literature.

Bone-tissue engineering is a therapeutic target in the field of dental implant and orthopedic surgery. It is therefore essential to find a microenvironment that enhances the growth and differentiation of osteoblasts both from mesenchymal stem cells (MSCs) and those derived from dental pulp. The aim of this review is to determine the relationship among the proteins fibronectin (FN), osteopontin (OPN), tenascin (TN), bone sialoprotein (BSP), and bone morphogenetic protein (BMP2) and their ability to coat different types of biomaterials and surfaces to enhance osteoblast differentiation. Pre-treatment of biomaterials with FN during the initial phase of osteogenic differentiation on all types of surfaces, including slotted titanium and polymers, provides an ideal microenvironment that enhances adhesion, morphology, and proliferation of pluripotent and multipotent cells. Likewise, in the second stage of differentiation, surface coating with BMP2 decreases the diameter and the pore size of the scaffold, causing better adhesion and reduced proliferation of BMP-MSCs. Coating oligomerization surfaces with OPN and BSP promotes cell adhesion, but it is clear that the polymeric coating material BSP alone is insufficient to induce priming of MSCs and functional osteoblastic differentiation in vivo. Finally, TN is involved in mineralization and can accelerate new bone formation in a multicellular environment but has no effect on the initial stage of osteogenesis.

Cirugía mínimamente invasiva en craneoestenosis / Minimal invasive surgery in craniostenosis

En el presente trabajo se describe la experiencia encraneoestenosis con cirugía mínimamente invasiva, evaluando el diseño y eficacia de un nuevo craneotomo n cadáveres así como su aplicación clínica en un caso de sinostósis sagital con instrumentación endoscópica. Este procedimiento es sin duda un gran recurso en el tratamiento de las craneoestenosis brindando los beneficios de la cirugía mínimamente invasiva, eliminándola necesidad de grandes incisiones, disminuyendo el sangrado quirúrgico, reduciendo estancia hospitalaria y disminuyendo la morbilidad operatoria (AU)

In this paper, we describe the experience with the use of endoscopic craniofacial procedures, evaluating the design and the efficacy of a new craniotome in cadavers and his clinical application in a case of sagittal synostosis for an endoscopic assisted cranioplasty. This procedure is a great option in the treatment of craniosynostosis, giving the benefits of minimal invasive surgery and eliminating the needing of big incisions, long hospital stay and reducing the postoperative morbidity (AU)

[Frequency of Chlamydia trachomatis in the cervix of pregnant women during prenatal examinations]. / Frecuencia de Chlamydia trachomatis en el cérvix de pacientes embarazadas en control prenatal.

From February 1993 to October 1995, 80 endocervical samples taken from 80 pregnant patients in pre-natal control were examined in private practice at the Hospital Angeles del Pedregal in Mexico City for purposes of detecting Chlamydia trachomatis by direct inmunoflorecency. Gestational ages ranged from 20 to 39 week. A positive reaction to Chlamydia trachomatis was observed in 10% (8 patients) of the participating patients. Taking into account this frequency it is suggested that this study be a part of prenatal control.

Training program for free transfer of skin grafts by microvascular anastomosis.

Microsurgery is a broad field, and offers possibilities of clinical and research applications. A program for training in skin transplant with arterial and venous anastomosis performed using a microtechnique, was instituted on the basis of numerous reports in world literature. The program was developed in four progressive stages which were, familiarization with the microscope and microsurgical setting, up to the transplant of an inguinal pediculated flat in the artery and lower superficial epigastric vein to the neck of the rat, through end-to-side patch anastomosis to the common carotid artery and the jugular vein. The favorable results confirm the advantages of microsurgery.

Adiestramiento en transplante cutaneo mediante anastomosis vascular con microtecnica. / Training program for free transfer of skin grafts by microvascular anastomosis

La microcirugia es un amplio campo con posibilidades de aplicacion clinica y de investigacion. Tomando como base numerosos informes de la literatura mundial, se diseno un programa de adiestramiento en transplante cutaneo con anastomosis arterial y venosa llevado a cabo con microtecnica. El programa se desarrollo en cuantro fases progresivas, que se iniciaron con familiarizacion con el microscopio y el ambiente microquirurgico, hasta el transplante de un colgajo inguinal pediculado en la arteria y la vena epigastricas inferiores superficiales al cuello de rata mediante anastomosis terminolateral en parche, a la arteria carotida primitiva y a la vena yugular. Los resultados favorables corroboran el beneficio que la microcirugia nos ofrece