Objective To explore if there are significant differences in the white matter and the myelinated fibers between left and right hemispheres of male rats and if the age-related changes of the white matter and the myelinated fibers in the white matter are same for left hemisphere and right hemisphere of male rats.Methods The white matter and the myelinated fibers in the white matter from 5 male young Long-Evans rats(6-8 month old) and 4 male aged Long-Evans rats(18 month old) were quantitatively investigated with the stereological techniques and transmission electronic microscope technique.Results There are no significant differences of the white matter and the mylinated nerve fibers in the white matter between the left and right hemispheres in both young and aged groups.Although the total volume of the white matter and the total length and the total volume of the myelinated nerve fibers in the white matter were reduced in both left hemisphere and right hemisphere,only the white matter volume and the total volume of the myelinated fibers in the white matter of right hemisphere and the total length of the myelinated fibers in the white matter of left hemisphere were significantly decreased by 32.9%,28.6% and 49.3%,respectively.Conclusion There are no significant differences in the white matter and myelinated nerve fiber in the white matter between left and right hemispheres in both young and aged male Long-Evans rats.The white matter volume and the total volume of the mylinaed fibers in the white matter of right hemisphere and the total length of the myelinated fibers in the white matter of left hemisphere in the aged male rats are significantly decreased when compared to young rats.
Objective Application of the new stereological techniques to investigate the age-related changes of the unmyelinated nerve fibers in rat white matter was described in order to figure out the exact reason for a decline of the myelinated nerve fibers in aged white matter.Methods In the present study,10 adult Long-Evans rats(6~8 months) and aged LongEvans rats(older than 18 months) were used.The volume density,length density, total volume and total length of the unmyelinated fibers in white matter were estimated with the stereological techniques and transmission electron microscope technique.Results(Both in) the male and female rats,there was no significant decrease of the total length of the unmyelinated fibes in white matter between young rats and aged rats.However,there was significant decrease of the total volume of the unmyelinated fibers in white matter,between young female rats and aged female rats,between young male and female rats together and aged male and female rats together.The total volume of the unmyelinated fibers in white matter of aged male rats was decreased by 31% when compared to that of young male rats even though the difference was not statistically significant.Conclusion In aged rat white matter,there was significant decrease of the unmyelinated fibers with large diameters.However,the myelinolysis of the myelinated fibers with small diameters made the decrease of the unmyelinated fibers with small diameters unnoticeable.The present study for the first time in the world combined the new stereological techniques and transmission electron microscope technique to quantitatively study the age-related changes of the unmyelinated fibers in rat white matter.The results of the present study will not only help the further understanding of age-related changes of nerve fibers in white matter but also provide the normal data of the volume and length of the unmyelinated fibers in the rat white matter that will provide the baseline value to compare with future studies on this animal model.
Abstract The loss of cervical lordosis is a common degenerative disorder known to be associated with abnormal spinal alignment. In recent years, ultrasound (US) imaging has been widely applied in the assessment of spine deformity and has shown promising results. The objectives of this study are to automatically segment bony structures from the 3D US cervical spine image volume and to assess the cervical lordosis on the key sagittal frames. In this study, a portable ultrasound imaging system was applied to acquire cervical spine image volume. The nnU-Net was trained on to segment bony structures on the transverse images and validated by 5-fold-cross-validation. The volume data were reconstructed from the segmented image series. An energy function indicating intensity levels and integrity of bony structures was designed to extract the proxy key sagittal frames on both left and right sides for the cervical curve measurement. The mean absolute difference (MAD), standard deviation (SD) and correlation between the spine curvatures of the left and right sides were calculated for quantitative evaluation of the proposed method. The DSC value of the nnU-Net model in segmenting ROI was 0.973. For the measurement of 22 lamina curve angles, the MAD±SD and correlation between the left and right sides of the cervical spine were 3.591±3.432° and 0.926, respectively. The results indicate that our method has a high accuracy and reliability in the automatic segmentation of the cervical spine and shows the potential of diagnosing the loss of cervical lordosis using the 3D ultrasound imaging technique.
Abstract Introduction: The induced membrane technique (IMT) is a two-stage procedure dedicated to reconstruction of bone defects of the limbs. The aim of this study was to investigate the effect of IMT in the treatment of infected tibial bone defect. Patients and methods: A retrospective study was performed among the patients treated using IMT for infected tibial bone defect between 2017 and 2020. The complications were recorded, and the bone defect union and the functional results were evaluated by Paley method. All patients were followed up for at least one year. Results We included 12 patients (11 males) with a mean age of 44.5 years (range 19 to 65). The mean length of bone defect was 26.7 mm (range 10 to 60). The mean interval between the stage one and the stage two of the procedure was 11.8 weeks (range 4 to 32). At a mean follow-up of 18.08 months (range 12 to 32), bone union was achieved in all cases in a mean time of 8 months (range 5 to 16) without infection recurrence, where one patient received additional bone grafting. The joint function recovered well for the patients and the rate of functionally excellent and good results was 9/12. Conclusion IMT in the treatment of infected tibial bone defect offers the advantages of simple operation, rapid healing of bone defects, and low recurrence rate of infection.
Objective:To assess the efficacy of pre-surgical MRI neuro-navigation system guided trans-sphenoidal resection of pituitary adenoma.Methods:42 patients with pituitary adenoma underwent MR scanning before surgery.3D image reconstruction,operation planning and marking of important anatomic structures were finished in the workstation of navigation system.All of the operation procedures were done under the guidance of MRI navigation system.Results:All of the MRI guided operation were successful,tumors were accurately localized with neuronavigation system,the mean error ranged from 0~1.9mm.Complete resection was revealed in 34 cases (80.9%) and subtotal resection in 8 cases (19.1%) on postoperative follow-up MRI.Conclusion:MRI neuro-navigation system is the first choice imaging modality in guiding trans-sphenoidal surgery for pituitary adenoma,images by high or low field MR scan fulfilled the requirement of neuronavigation.
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