CD73 as a target to improve temozolomide chemotherapy effect in glioblastoma preclinical model

Glioblastoma is the most devastating primary brain tumor and effective therapies are not available. Treatment is based on surgery followed by radio and chemotherapy with temozolomide (TMZ), but TMZ increases patient survival only by 2 months. CD73, an enzyme responsible for adenosine production, emerges as a target for glioblastoma treatment. Indeed, adenosine causes tumor-promoting actions and CD73 inhibition increases sensitivity to TMZ in vitro. Here, a cationic nanoemulsion to nasal delivery of siRNA CD73 (NE-siRNA CD73) aiming glioblastoma treatment was employed alone or in combination with TMZ. In vitro, two glioblastoma cell lines (C6 and U138MG) with a chemo-resistant profile were used. Treatment alone with NE-siRNA CD73 reduced C6 and U138MG glioma cell viability by 70% and 25%, respectively. On the other hand, when NE-siRNA + TMZ combined treatment was employed, a reduction of 85% and 33% of cell viability was observed. Notably, treatment with NE-siRNA CD73 of glioma-bearing Wistar rats reduced tumor size by 80%, 60% more than the standard chemotherapy with TMZ, but no synergistic or additive effect was observed in vivo. Additionally, NE-siRNA CD73, TMZ or combined therapy decreased adenosine levels in liquor confirming the importance of this nucleoside on in vivo GB growth. Finally, no hemolytic potential was observed. These results suggest that nasal administration of NE-siRNA CD73 exhibits higher antiglioma effect when compared to TMZ. However, no synergistic or additive in vivo was promoted by the therapeutic regimen employed in this study.

Design and Fabrication of a Hybrid Diffractive Optical Device for Multiple-Line Generation over a Wide Angle

A new hybrid optical device that is capable of splitting a monochromatic laser beam into an arbitrary number of lines over a wide angle is presented. It consists of a binary surface-relief computer-generated phase hologram and a continuous parabolic surface-relief grating. In this device the phase hologram serves to generate three small, parallel lines while the continuous parabolic surface-relief phase grating acts as an array of diverging parabolic lenses to widen these lines. The binary surface-relief was generated into one side of a quartz substrate through a plasma-etching process, and the parabolic profile was generated into a thick photoresist deposited on the other side of the quartz substrate. Calculations showed that a diverging parabolic lens with a f-number of 0.5 would deliver the desired optical pattern of multiple beams distributed over 90 degrees . A surface-relief depth of 6.0 mum was calculated with consideration of the phase distributions of such lens. The parabolic profiles were fabricated in a 10-mum-thick photoresist, by use of a contact exposure through a mask with a space pattern of repetitive 4- and 6-mum lines. He-Ne laser light was passed through a device that generated three parallel lines over a 90 degrees angle. The resulting diffraction patterns were characterized, and a satisfying result was obtained. The resulting multiple-line pattern can be used in robot vision and other applications.

Anatomic variations of anterior cerebral artery cortical branches

The anterior cerebral artery (ACA) is a major vessel responsible for the blood supply to the interhemispheric region. The ACA segment after the anterior communicating artery (AComA) origin is called the distal ACA and has central and cortical branches. The cortical branches are distributed in the different regions of the orbital and medial part of the brain. The objects of this study are the anatomical variations found in the distal ACA. In 76 hemispheres the ACA distal branches were injected with latex and dissected under microscope magnification. Vessel diameters and distances between vessel origins and anterior communicating artery were recorded and analyzed. Microsurgical dissection was carried out to demonstrate anatomic variations of these vessels. Average diameter of ACA at origin was 2.61 +/- 0.34 mm and average diameter of cortical branches diameter ranged from 0.79 +/- 0.27 mm to 1.84 +/- 0.3 mm. Distances between vessel origin and AComA ranged from 7.68 +/- 3.91 mm (orbitofrontal) to 112.6 +/- 11.63 mm (inferior internal parietal). This study found anatomical variations: a single (azygos) ACA was present in one case and three in three cases. Crossing branches of the distal ACA to the contralateral hemisphere were present in 26% of the cases. In some cases a single ACA may supply the posterior hemispheric region through crossing branches. This calls attention to potential bilateral brain infarcts due to a single unilateral ACA occlusion.

Perforating and leptomeningeal branches of the anterior communicating artery: an anatomical review

The morphological variability, diameter, and length of the anterior communicating artery (ACoA) are important factors in clinical and surgical decisions. This artery presents branches that supply the optic nerves and chiasm, the lamina terminalis, the hypothalamus, and the subcallosal region. The ACoA has the most frequent incidence of saccular aneurysms in the anterior portion of the circle of Willis. Lesions to the ACoA's branches may be related to neuropsychological sequelae such as amnesia, confabulation and personality changes, besides other basal ganglia syndromes. In this paper, anatomical studies of the ACoA and its branches are reviewed and the results of an anatomical study carried out in our laboratory presented.