A Redox-Sensitive Luciferase Assay for Determining the Localization and Topology of Endoplasmic Reticulum Proteins

Correct localization and transmembrane topology are crucial for the proteins residing and functioning in the endoplasmic reticulum (ER). We have developed a rapid and convenient assay, based on the redox-sensitive luciferase from Gaussia princeps (Gluc) and green fluorescence protein (GFP), to determine the localization or topology of ER proteins. Using the tandem Gluc-GFP reporter fused to different positions of a target protein, we successfully characterized the topologies of two ER transmembrane proteins Herp and HRD1 that are involved in the ER quality control system. This assay method may also be applicable to the proteins in secretory pathway, plasma membrane, and other compartments of cells

1,3-Bis[(4-nitro­benzyl­idene)amino­oxy]propane

The complete molecule of title compound, C17H16N4O6, is generated by a crystallographic twofold axis. Within the mol­ecule, the two benzene units are approximately perpen­dicular, making a dihedral angle of 85.91 (4)°. In the crystal, mol­ecules are linked into a three-dimensional network by C—H⋯O hydrogen bonds and short O⋯O and N⋯O inter­actions, with distances of 2.998 (2) and 2.968 (3) Å, respectively

A Novel Animal Model for Subarachnoid Hemorrhage in Rabbits - Pathology due to Hemorrhage

The Pathophysiological course of subarachnoid hemorrhage (SAH) is not completely understood, such as  how and why blood or its lysate can influence the brain. Although many SAH animal models have previously  been reported, none are suitable for research in this field. The aim of the present study was to establish  such an animal model. Twenty New Zealand rabbits were divided into two groups, a control group and  a SAH group (n=10). Blood was lysed using an in vitro freeze-thaw method. After anesthesia, 0.9 ml of  cerebrospinal fluid was drawn from both groups. An identical volume of heparinized hemolysate was then  slowly injected into the cisterna magna of the SAH group animals. Control group animals while the control  group received heparinized isotonic sodium chloride solution. Forty-eight hours post-injection, samples  were excised after perfusion fixation for further determinations. The degree of cerebral vasospasm was  evaluated by measuring the cross-sectional area of the basilar arterial lumen, and brain damage was examined  by TUNEL staining. Weight, blood pressure and saturation of blood oxygen showed no statistical differences  between groups. The cross-sectional area of the arterial lumen in the SAH group was roundly  0.402 mm2, which was statistically the same as that for the control group (0.435 mm2). The apoptosis index  for the SAH group was significantly higher than that for the control group. Taken together, our results show  that this model is effective in reproducing the influence of blood on the brain after SAH and, at the same  time, strictly excludes influences on the brain by other factors. Thus, this model can effectively be applied  to investigate blood-related neuropathophysiology following SAH.

The development and evaluation of individualized templates to assist transoral C2 articular mass or transpedicular screw placement in TARP-IV procedures: adult cadaver specimen study

OBJECTIVES: The transoral atlantoaxial reduction plate system treats irreducible atlantoaxial dislocation from transoral atlantoaxial reduction plate-I to transoral atlantoaxial reduction plate-III. However, this system has demonstrated problems associated with screw loosening, atlantoaxial fixation and concealed or manifest neurovascular injuries. This study sought to design a set of individualized templates to improve the accuracy of anterior C2 screw placement in the transoral atlantoaxial reduction plate-IV procedure. METHODS: A set of individualized templates was designed according to thin-slice computed tomography data obtained from 10 human cadavers. The templates contained cubic modules and drill guides to facilitate transoral atlantoaxial reduction plate positioning and anterior C2 screw placement. We performed 2 stages of cadaveric experiments with 2 cadavers in stage one and 8 in stage two. Finally, guided C2 screw placement was evaluated by reading postoperative computed tomography images and comparing the planned and inserted screw trajectories. RESULTS: There were two cortical breaching screws in stage one and three in stage two, but only the cortical breaching screws in stage one were ranked critical. In stage two, the planned entry points and the transverse angles of the anterior C2 screws could be simulated, whereas the declination angles could not be simulated due to intraoperative blockage of the drill bit and screwdriver by the upper teeth. CONCLUSIONS: It was feasible to use individualized templates to guide transoral C2 screw placement. Thus, these drill templates combined with transoral atlantoaxial reduction plate-IV, may improve the accuracy of transoral C2 screw placement and reduce related neurovascular complications

Indications of magnetic coupling effects in spin cross-over molecular thin films

Room temperature isothermal reversible spin crossover switching of [Fe(H2B(pz)2)2(bipy)] thin films is demonstrated. The magnetic oxide substrate locks the [Fe{H2B(pz)2}2(bipy)] largely in a low spin state. With an X-ray fluence, excitation to a high spin state occurs, while relaxation back to low spin state is aided by alternating the substrate magnetization. Includes supplementary materials

Dual Energy Spectral CT Imaging for Colorectal Cancer Grading: A Preliminary Study

ObjectivesTo assess the diagnostic value of dual energy spectral CT imaging for colorectal cancer grading using the quantitative iodine density measurements in both arterial phase (AP) and venous phase (VP).Methods81 colorectal cancer patients were divided into two groups based on their pathological findings: a low grade group including well (n = 13) and moderately differentiated cancer (n = 24), and a high grade group including poorly differentiated (n = 42) and signet ring cell cancer (n = 2). Iodine density (ID) in the lesions was derived from the iodine-based material decomposition (MD) image and normalized to that in the psoas muscle to obtain normalized iodine density (NID). The difference in ID and NID between AP and VP was calculated.ResultsThe ID and NID values of the low grade cancer group were, 14.65±3.38mg/mL and 1.70±0.33 in AP, and 21.90±3.11mg/mL and 2.05± 0.32 in VP, respectively. The ID and NID values for the high grade cancer group were 20.63±3.72mg/mL and 2.95±0.72 in AP, and 26.27±3.10mg/mL and 3.51±1.12 in VP, respectively. There was significant difference for ID and NID between the low grade and high grade cancer groups in both AP and VP (all p<0.001). ROC analysis indicated that NID of 1.92 in AP provided 70.3% sensitivity and 97.7% specificity in differentiating low grade cancer from high grade cancer.ConclusionsThe quantitative measurement of iodine density in AP and VP can provide useful information to differentiate low grade colorectal cancer from high grade colorectal cancer with NID in AP providing the greatest diagnostic value