Objective To investigate the effect of dorsal repulsive axon guidance protein(Draxin)on the migration of trunk neural crest cells during the early development of embryonic mouse spinal cord.Methods Immunohistochemistry and in situ hybridization were used to detect the expression characteristics of Draxin in early embryonic spinal cord(8 mice each group);In situ hybridization was used to detect the change of migration characteristics of trunk neural crest cells in early embryonic spinal cord of different types of mouse(5 mice each group);in vitro culture method was used to check the effect of Draxin on the migration characteristics of embryonic mouse trunk neural crest cells(16 mice each group).Resultsβ-galactosidase gene Z(LacZ)gene was introduced when Draxin gene was knocked out to produce Draxin gene knockout mice.β-galactosidase staining was used to detect LacZ gene expression in Draxin knockout embryonic mice,and the result showed that Draxin expression was observed in the spinal cord of early embryonic mice since 9.5 days(E9.5).Draxin expression was obvious in the embryonic mice spinal cord in E10.5 period.In situ hybridization was used to detect the expression of Draxin gene in the spinal cord of wild type embryonic mice,and the result further verified the obvious expression of Draxin in the early embryonic mice spinal cord in El0.5 period.Sox10 in situ hybridization was used to detect neural crest cell migration in the spinal cord of embryonic mice in E10.5 period.The result showed that segmental migration of neural crest cells in the early embryonic spinal cord of some Draxin knockout mice was delayed compared with the wild type mice.The effect of Draxin on the migration of wild type early embryonic mice trunk neural crest cells in vitro was tested.The result showed that Draxin reduced the migration distance of neural crest cells in vitro.Conclusion In the early developmental stage of embryonic spinal cord(E9.5-E10.5),neural crest cells migrated exuberant.At the same time,Draxin plays an important inhibitory function in the formation of the specific migration pathways of trunk neural crest cells by promoting neural crest cells migrating away from Draxin expressing regions.

[Abstract] Objective To investigate the effects of the downregulation of draxin expression on the projection characteristics of 23C10-positive neural fibers in the chick embryonic hindbrain. Methods The vitro incubation of HH stages 21-22 chick embryonic hindbrain biopsy with alkaline phosphatase (ALP) protein was used as control group. The incubation of HH stages 21-22 chick embryonic hindbrain biopsy with draxin-ALP fusion protein was used as experimental group. The number of embryonic hindbrain for each group was 10. To detect whether 23C10-positive neural fibers could directly bind to draxin protein or not;In ovo electroporation using empty vector in the chick embryonic hindbrain was used as control group. In ovo electroporation with small interfering RNA(siRNA) expressing vector for reducing draxin expression in the chick embryonic hindbrain was used as experimental group. The number of embryonic hindbrain for each group was 18. The effect of the down-regulation of draxin expression and the change of projection characteristics of 23C10-positive neural fibers were observed to check whether the down-regulation of draxin expression would affect the distribution of 23C10-positive fibers. Results Most portion of draxin protein could overlap with 23C10-positive neural fibers in HH stages 21-22 chick embryonic hindbrain biopsies; After expression of the siRNA plasmid against draxin by electroporation, the expression level of draxin protein was significantly reduced, and the distribution of 23C10-positive fibers was scattered in the dorsal hindbrain on the electroporated side at HH stages 25-26 of chick embryos (P < 0. 05) . Conclusion Draxin protein may directly bind to 23C10-positive fibers in hindbrain, and it plays an important regulatory role in the fasciculation of 23C10-positive fibers during chick embryonic development.

BACKGROUNDAccurate evaluation of response following chemotherapy treatment is essential for surgical decision making in patients with breast cancer. Modalities that have been used to monitor response to neo-adjuvant chemotherapy (NAC) include physical examination (PE), ultrasound (US), and magnetic resonance imaging (MRI). The purpose of this study was to evaluate the accuracy of PE, US, and MRI in predicting the response to NAC in patients with breast cancer.

METHODSAccording to the response evaluation criteria in solid tumors guidelines, the largest unidimensional measurement of the tumor diameter evaluated by PE, US, and MRI before and after NAC was classified into four grades, including clinical complete response, clinical partial response, clinical progressive disease, clinical stable disease, and compared with the final histopathological examination.

RESULTSOf the 64 patients who received NAC, the pathologic complete response (pCR) was shown in 13 of 64 patients (20%). The sensitivity of PE, US, and MRI in predicting the major pathologic response was 73%, 75%, and 80%, respectively, and the specificity was 45%, 50%, and 50% respectively. For predicting a pCR, the sensitivity of PE, US, and MRI was 46%, 46%, and 39%, respectively, and the specificity was 65%, 98%, and 92% respectively.

CONCLUSIONSCompared with final pathologic findings, all these three clinical and imaging modalities tended to obviously underestimate the pCR rate. A more appropriate, universal, and practical standard by clinical and imaging modalities in predicting the response to neo-adjuvant chemotherapy in vivo is essential.

Adult ; Aged ; Breast Neoplasms ; diagnostic imaging ; drug therapy ; pathology ; Chemotherapy, Adjuvant ; Female ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Physical Examination ; Ultrasonography

Background Accurate evaluation of response following chemotherapy treatment is essential for surgical decision making in patients with breast cancer.Modalities that have been used to monitor response to neo-adjuvant chemotherapy (NAC) include physical examination (PE),ultrasound (US),and magnetic resonance imaging (MRI).The purpose of this study was to evaluate the accuracy of PE,US,and MRI in predicting the response to NAC in patients with breast cancer.Methods According to the response evaluation criteria in solid tumors guidelines,the largest unidimensional measurement of the tumor diameter evaluated by PE,US,and MRI before and after NAC was classified into four grades,including clinical complete response,clinical partial response,clinical progressive disease,clinical stable disease,and compared with the final histopathological examination.Results Of the 64 patients who received NAC,the pathologic complete response (pCR) was shown in 13 of 64 patients (20％).The sensitivity of PE,US,and MRI in predicting the major pathologic response was 73％,75％,and 80％,respectively,and the specificity was 45％,50％,and 50％ respectively.For predicting a pCR,the sensitivity of PE,US,and MRI was 46％,46％,and 39％,respectively,and the specificity was 65％,98％,and 92％ respectively.Conclusions Compared with final pathologic findings,all these three clinical and imaging modalities tended to obviously underestimate the pCR rate.A more appropriate,universal,and practical standard by clinical and imaging modalities in predicting the response to neo-adjuvant chemotherapy in vivo is essential.

This paper describes a calibration phantom system for QCT bone mineral density determination, which consists of 4-standard-solid-sample calibration phantom, a quality assurance (QA) phantom and the bone mineral density analysis software. The system adds to the new applications of CT systems, and provides a new method with a good accuracy and reliability for the examination, diagnosis, prevention, treatment of osteoporosis diseases and the observation of curative effect of drugs.
Absorptiometry, Photon ; instrumentation ; methods ; Algorithms ; Animals ; Bone Density ; Calibration ; Equipment Design ; Humans ; Image Processing, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; methods ; Osteoporosis ; diagnostic imaging ; Phantoms, Imaging ; Software ; Tomography, X-Ray Computed ; instrumentation ; methods