Biomedical subjects

Ming-Dar Tsai

Publications and source records attributed to Ming-Dar Tsai.

7 recordsLinked to original sources

PubMed2007

Injury-induced Janus kinase/protein kinase C-dependent phosphorylation of growth-associated protein 43 and signal transducer and activator of transcription 3 for neurite growth in dorsal root ganglion.

Elevation of corticosteroids and excessive glutamate release are the two major stress responses that occur sequentially during traumatic CNS injury. We have previously reported that sequential application of corticosterone and kainic acid (CORT + KA) mimicking the nerve injury condition results in synergistic enhancement of neurite outgrowth and expression of growth-associated protein 43 (GAP-43) in cultured dorsal root ganglion (DRG). GAP-43 is known to promote neurite extension when phosphorylated by protein kinase C (PKC). In addition, PKC can phosphorylate the signal transducer and activator of transcription 3 (STAT3) at Ser727, which is phosphorylated primarily by Janus kinase (JAK) at Tyr705. In this study, we further examine the role of PKC in this stress-induced growth-promoting effect. In the cultured DRG neurons, the JAK inhibitor AG-490 and the PKC inhibitor Ro-318220 reduced the CORT + KA-enhanced neurite growth effect when applied prior to CORT and KA treatment, respectively. Both AG-490 and Ro-318220 diminished the CORT + KA-enhanced GAP-43 expression, phosphorylation, and axonal localization. Furthermore, CORT + KA treatment synergistically phosphorylated STAT3 at Ser727 but not at Tyr705. Similar phenomena were observed in an animal model of acute spinal cord injury (SCI), in which phosphorylation of GAP-43 and phospho-Ser727-STAT3 was elevated in the injured DRG 4 hr after the impact injury. Further treatment with the therapeutic glucocorticoid methylprednisolone enhanced the phosphorylation of GAP-43 in both the DRG and the spinal cord of SCI rats. These results suggest that elevated glucocorticoids and overexcitation following CNS injury contribute to nerve regeneration via induction of JAK/PKC-mediated GAP-43 and STAT3 activities.

Animals↗

PubMed2006

Development of a personal digital assistant-based wireless application in clinical practice.

PURPOSE: Our study aims to develop a personal digital assistant (PDA)-based wireless application in medical information processing by using Bluetooth and IEEE 802.11b wireless standards and SyncML codes. METHODS: In this study, an "integrated database access module" is used to provide a unified integrated access interface while consistency of wireless data transmission is achieved by using the standardized SyncML protocol. A prototype of the system has been developed, implemented, and tested for its mobility, usability, stability, and performance with questionnaire survey. RESULTS: Response time for browsing/searching was usually less than 3s. The average time intervals needed for data transmissions were 68.6+/-8.5s for Bluetooth and 47.0+/-4.8s for 802.11b. The five-point Likert scale (from 1=least to 5=most) questionnaire survey of 30 medical professionals yielded a high degree of satisfaction with the system's mobility (4.18+/-0.89), usability (4.69+/-0.90), stability (3.81+/-0.94), and performance (3.97+/-0.88). CONCLUSION: The results of our study suggested that PDA applications which exploit wireless communication are convenient and feasible in clinical practice.

Computers, Handheld↗

PubMed2005

Three-dimensional hip morphology analysis using CT transverse sections to automate diagnoses and surgery managements.

This paper describes an image analysis method that evaluates bone morphology of hip structures including the femur stem, trochanter, neck and head, acetabulum, and pelvis to automate hip diagnoses and surgical managements. On every CT transverse section, radial B-spline curves are used to approximate the ellipse-like acetabulum and femur head and stem. The femur neck is approximated as trapezoid-like and the pelvis horizontally symmetrical structure. The centers of the ellipse-like structures from transverse sections are used to determine 3D axes of the femur stem, head, and acetabulum. The centerlines of the neck or the pelvis on the sections are used to determine the neck axis or pelvis centerplane. Boundary changes of these structures are recognized as concave, convex and hole features that are then identified as fractures, tumors, and spurs. Based on the geometric evaluations of these structures and features, hip surgeries including tumor dissect and bone graft, open reduction using plates, screws and nails, and arthroplasty are automatically managed to achieve the normal hip function including dissection of tumors and reduction of dislocations and angular deviations between the hip structures. This prototype system can be used as a qualitative and quantitative tool for the diagnosis of various hip diseases and for the planning of accurate surgical procedures. A series of examples and four case studies illustrate this automated method can be used to accurately diagnose hip diseases and manage hip surgeries, and train operators.

Adult↗

PubMed2005

Volume manipulations for simulating bone and joint surgery.

Bone and joint surgery is widely used in orthopedic, oral, and maxillofacial, and dental and plasty departments to correct bone and joint pathology such as bone and joint tumors and fractures, and skeletal morphological deformities. This article presents a voxel structure to represent topologically and geometrically correct surfaces and algorithms to accurately compute intersections of tool swept surfaces with bones based on this voxel structure. This article then presents various volume manipulation algorithms to operate on virtual bones, bone grafts, and prostheses for bone and joint surgery simulations. A complicated knee arthroplasty illustrates the practicality and versatility of the proposed method.

Arthroplasty↗

PubMed2004

Automatic spinal disease diagnoses assisted by 3D unaligned transverse CT slices.

This paper describes a three-dimensional (3D) reconstruction method and an automatic diagnosis method for spinal diseases using unaligned transverse slices that have arbitrary angles and intervals but do not intersect to each other at regions of interest. The 3D reconstruction method extends the marching cube algorithm to generate triangulated isosurfaces for these unaligned slices. The automatic spinal disease diagnostic method analyses boundaries of discs and vertebral bodies on unaligned transverse slices to estimate the presence and extent of disc herniation and canal compression, and deformities in the spinal curve. The prototype system can be used as a qualitative and quantitative tool for the diagnosis of various spinal diseases using unaligned transverse slices.

Aged↗

PubMed2002

Resection of giant olfactory groove meningioma with extradural devascularization.

A 55-year-old male patient presented with a giant olfactory groove meningioma supplied by both ophthalmic arteries. The tumor was debulked through a bifrontal craniotomy, but the surgery was discontinued because of extensive blood loss. During a second operation, the dura of the frontal base was dissected extradurally before the tumor was removed. The meningeal blood supply was occluded with bipolar coagulation of the epidural meningeal vessels around the crista galli. The highly vascular tumor then was totally removed with considerably less blood loss. The patient's postoperative course was uneventful. Because the ophthalmic artery cannot be embolized preoperatively, the direct extradural approach to the skull base to devascularize the blood supply around the olfactory groove may reduce blood loss and facilitate resection.

Case Reports↗

PubMedDate not supplied

Cytologic diagnosis of a metastatic oligodendroglioma in a pleural effusion. A case report.

BACKGROUND: Extraneural metastasis of oligodendroglioma is extremely rare and is diagnosed primarily by biopsy or autopsy and very occasionally by fine needle cytologic examination. We report a case of metastatic oligodendroglioma diagnosed by cytologic examination of a pleural effusion. Such a diagnosis has not been reported before. CASE: A 64-year-old woman developed anemia and bilateral pleural effusion 7 years after an operation for an oligodendroglioma over the left frontal lobe. Cytologic examination of the pleural effusion showed aggregates of atypical polygonal cells containing round, hyperchromatic nuclei and scanty, granular cytoplasm in Liu's and Papanicolaou stain and cell blocks. Immunohistochemical staining of the tumor cells revealed a positive reaction for antibodies to glial fibrillary acidic protein, S-100 and Olig2. Pleural biopsy confirmed the cytologic diagnosis of pleural effusion. A pathologic fracture of the right humeral and femoral bones was noted 1 month later, and the specimen also showed infiltrating oligodendroglioma cells in bone tissue. CONCLUSION: To the best of our knowledge, this is the first metastatic oligodendroglioma diagnosed by pleural cytology. Fine needle cytology can provide a reliable and rapid way to detect an extracranial metastatic oligodendroglioma in different organs.

Basic Helix-Loop-Helix Proteins↗