Segment-Specific Orientation of the Dorsal and Ventral Roots for Precise Therapeutic Targeting of Human Spinal Cord

Objective: To provide precise description of the dorsal and ventral roots orientation along with the main spinal cord anatomical measurements and their segment-specific variations. Patients and Methods: We collected and analyzed the measurements of the spines, spinal cords, and dorsal and ventral roots (C2-L5) of nine adult cadavers (five males and four females). Results: This study for the first time provides analysis of the dorsal and ventral roots orientation along with spinal cord anatomical measurements and their segment-specific distribution. The results of this study showed less variability in rostral root angles compared with the caudal. Dorsal and ventral rootlets were oriented mostly perpendicular to the spinal cord at the cervical level and had more parallel orientation to the spinal cord at the thoracic and lumbar segments. The number of rootlets per root was greatest at dorsal cervical and lumbar segments. Spinal cord transverse diameter and width of the dorsal columns were largest at cervical segments. The strongest correlation between the spinal cord and vertebrae structures was found between the length of intervertebral foramen to rostral rootlet distance and vertebral bone length. Conclusion: These results demonstrate consistent variation in spinal cord anatomical features across all tested subjects. The results of this study can be used to locate spinal roots and main spinal cord landmarks based on bone marks on computed tomography or X-rays. These results could improve stereotactic surgical procedures and electrode positioning for neuromodulation procedures

Hippocampal gene expression profiling across eight mouse inbred strains: towards understanding the molecular basis for behaviour

Mouse inbred strains differ in many aspects of their phenotypes, and it is known that gene expression does so too. This gives us an opportunity to isolate the genetic aspect of variation in expression and compare it to other phenotypic variables. We have investigated these issues using an eight-strain expression profile comparison with four replicates per strain on Affymetrix MGU74av2 GeneChips focusing on one well-defined brain tissue (the hippocampus). We identified substantial strain-specific variation in hippocampal gene expression, with more than two hundred genes showing strain differences by a very conservative criterion. Many such genetically driven differences in gene expression are likely to result in functional differences including differences in behaviour. A large panel of inbred strains could be used to identify genes functionally involved in particular phenotypes, similar to genetic correlation. The genetic correlation between expression profiles and function is potentially very powerful, especially given the current large-scale generation of phenotypic data on multiple strains (the Mouse Phenome Project). As an example, the strongest genetic correlation between more than 200 probe sets showing significant differences among our eight inbred strains and a ranking of these strains by aggression phenotype was found for Comt, a gene known to be involved in aggression

Development and evaluation of a chronotherapeutic drug delivery system of torsemide

The objective of this study was to prepare and evaluate chronotherapeutic drug delivery systems (ChrDDs) of torsemide. Compression coated tablets (CCT) containing torsemide in the core tablet were prepared by the compression coating technique with different grades of polyethylene oxide (PEO WSR 301 & 1105). The optimized formulations were characterised for tabletting parameters and drug polymer interaction by Fourier-Transform Infrared Spectroscopy (FTIR).The hardness of all the CCT using PEO WSR 301 & PEO WSR 1105 were in the range 6-8 kg/cm² & 5.5 to 7 kg/cm² respectively. Their friability values were <0.3%. All the CCT showed a clear lag time but finalized as per the predetermined lag time. As the amount of PEO was increased in the outer layer the drug released was delayed. The drug content of all the CCT was >99%. The FTIR studies showed no interaction throughout the process of development. Formulations of F7 and of P7 were considered optimized formulations since they yielded a predetermined lag time of 6h before burst release. Hence, these formulations can be exploited to achieve chronotherapeutic drug delivery systems of Torsemide for the treatment of hypertension at the time the patient needs it.<br>O objetivo deste estudo foi preparar e avaliar sistemas cronoterapêuticos de liberação de fármacos (ChrDDs) de torsemida. Comprimidos revestidos por compressão (CCT) contendo torsemida no (núcleo) foram preparados pela técnica de revestimento por compressão, com diferentes categorias de óxido de polietileno (PEO WSR 301 & 1105). As formulações otimizadas foram caracterizadas por parâmetros de compressão e interação fármaco polímero por Infravermelho com Transformada de Fourier (FTIR). A dureza dos CCT utilizando PEO WSR 301 e PEO WSR 1105 foi entre 6-8 kg/cm² e 5,5 a 7 kg/cm², respectivamente. Os valores de friabilidade foram <0,3%. Todos os CCT mostraram claro tempo de retardo, mas finalizaram de acordo com o tempo de retardo pré-determinado. À medida que a quantidade de PEO aumentava na camada mais externa, a liberação do fármaco era retardada. O teor de fármaco em todos os CCT foi >99%. Os estudos de FTIR mostraram que não h[a interação durante o processo de desenvolvimento. As formulações F7 e P7 foram consideradas otimizadas, uma vez que resultaram em tempo de retardo pré-determinado de 6 h antes da liberação por meio de explosão. Dessa forma, estas formulações podem ser exploradas para se obter sistemas de liberação