Positioning error analysis of the fraxion localization system in the intracranial stereotactic radiotherapy of tumors.

OBJECTIVE: To investigate positioning error analysis of the Fraxion localization system in the intracranial stereotactic radiotherapy of tumors. METHODS: 64 patients were divided into two groups: a control group (36 patients with the standard thermoplastic mask) and a model group (28 patients with the Fraxion localization system). 3D images of the treated position were obtained by cone-beam computed tomography (CBCT). Positioning errors were obtained by, respectively, registering these two sets of CBCT images to planning CT images, using a 6°-freedom robotic patient positioning system (HexaPOD Evo RT System). The changes in positioning errors with the Fraxion localization system and with the standard thermoplastic mask were analyzed. RESULTS: CBCT scan results of the model group showed that the mean of linear error of three directions [superior-inferior (SI), lateral (LAT), and anterior-posterior (AP)] was 0.710 ± 0.676 mm, 0.817 ± 0.687 mm, and 0.710 ± 0.685 mm, respectively. The corresponding PTV was 1.23 mm, 1.26 mm, and 1.36 mm. The differences between the 3D images and the planned CT images were significant (p < 0.001). CONCLUSION: The Fraxion radiotherapy system can not only improve the positioning accuracy and reduce positioning errors but also narrow the PTV margin and reduce the radiated volume of normal tissue.

Voluntary exercise prior to traumatic brain injury alters miRNA expression in the injured mouse cerebral cortex

MicroRNAs (miRNAs) may be important mediators of the profound molecular and cellular changes that occur after traumatic brain injury (TBI). However, the changes and possible roles of miRNAs induced by voluntary exercise prior to TBI are still not known. In this report, the microarray method was used to demonstrate alterations in miRNA expression levels in the cerebral cortex of TBI mice that were pretrained on a running wheel (RW). Voluntary RW exercise prior to TBI: i) significantly decreased the mortality rate and improved the recovery of the righting reflex in TBI mice, and ii) differentially changed the levels of several miRNAs, upregulating some and downregulating others. Furthermore, we revealed global upregulation of miR-21, miR-92a, and miR-874 and downregulation of miR-138, let-7c, and miR-124 expression among the sham-non-runner, TBI-non-runner, and TBI-runner groups. Quantitative reverse transcription polymerase chain reaction data (RT-qPCR) indicated good consistency with the microarray results. Our microarray-based analysis of miRNA expression in mice cerebral cortex after TBI revealed that some miRNAs such as miR-21, miR-92a, miR-874, miR-138, let-7c, and miR-124 could be involved in the prevention and protection afforded by voluntary exercise in a TBI model.

Voluntary exercise prior to traumatic brain injury alters miRNA expression in the injured mouse cerebral cortex.

MicroRNAs (miRNAs) may be important mediators of the profound molecular and cellular changes that occur after traumatic brain injury (TBI). However, the changes and possible roles of miRNAs induced by voluntary exercise prior to TBI are still not known. In this report, the microarray method was used to demonstrate alterations in miRNA expression levels in the cerebral cortex of TBI mice that were pretrained on a running wheel (RW). Voluntary RW exercise prior to TBI: i) significantly decreased the mortality rate and improved the recovery of the righting reflex in TBI mice, and ii) differentially changed the levels of several miRNAs, upregulating some and downregulating others. Furthermore, we revealed global upregulation of miR-21, miR-92a, and miR-874 and downregulation of miR-138, let-7c, and miR-124 expression among the sham-non-runner, TBI-non-runner, and TBI-runner groups. Quantitative reverse transcription polymerase chain reaction data (RT-qPCR) indicated good consistency with the microarray results. Our microarray-based analysis of miRNA expression in mice cerebral cortex after TBI revealed that some miRNAs such as miR-21, miR-92a, miR-874, miR-138, let-7c, and miR-124 could be involved in the prevention and protection afforded by voluntary exercise in a TBI model.

Cloning and expression of cDNA encoding antistasin, a leech-derived protein having anti-coagulant and anti-metastatic properties.

As a factor Xa inhibitor, antistasin is a potent anti-coagulant and anti-metastatic agent that is found in the salivary gland of the Mexican leech Haementaria officinalis. cDNA clones that encode antistasin have been isolated. Subsequent sequence analysis and comparison with the amino acid sequence of the mature protein indicates that antistasin is produced as a pre-protein containing a 17-amino acid signal peptide. Antistasin exists as at least two variants. By sequence analysis of multiple cDNA clones, we found two additional sites for amino acid substitutions, confirming variants that differ from each other by amino acid changes at a minimum of four residues. These sequence variations appear to be the result of allelic variation rather than gene duplication as deduced from DNA blot analyses. Sequence data suggest that antistasin may have evolved from a smaller ancestral gene by a duplication event giving rise to a two-fold structural homology between the N- and C-terminal halves of the molecule. Insect cells transfected with a recombinant baculovirus expressed antistasin which was biologically active and had an electrophoretic mobility identical to that of the native molecule.