BACKGROUND:It remains unclear what kind of changes in imaging and histopathology would appear in intervertebral disc after removal of nucleus pulposus over time.
OBJECTIVE:To observe the alteration in imaging and histopathology of rabbit lumbar intervertebral disc after nucleus pulposus aspiration.
METHODS:A total of 32 Japanese rabbits were subjected to nucleus pulposus aspiration in posterior lateral L 3/4 intervertebral disc with a 21-gauge hypodermic needle. L 2/3 intervertebral disc served as a normal control. At 2, 4, 8 and 12 weeks after aspiration, eight rabbits according to grouping received radiograph in the lateral position of lumbar vertebra. The height of L 3/4 and L 2/3 intervertebral space was measured and intervertebral disc height index was calculated. Rabbits received median sagittal MRI examination and histopathological examination of intervertebral disc.
RESULTS AND CONCLUSION:The intervertebral disc height degraded slowly at 2, 4, 8, and 12 weeks after aspiration. However, the difference between 8 and 12 weeks was reduced. Compared with normal control, intervertebral disc height index significantly reduced at various time points (P<0.05). The nucleus pulposus signal intensity was gradual y reduced at 2, 4, 8, and 12 weeks after aspiration, and reached grade 4 of modified Thompson grading criteria at 8 weeks. After aspiration, gelatinous nucleus pulposus of disc slowly exhibited fissures with time, morphous was slowly disordered and showed significant fibrosis performance at 12 weeks. In nucleus pulposus region, more cartilage-like cells were found at 4 weeks after operation. The cells were active. Nucleus pulposus cells decreased significantly. At 8 and 12 weeks after operation, fibroblasts increased in nucleus pulposus region, and the number of cartilage-like cells reduced. The annulus fibrosus gradual y became distorted, disordered, with processes and layers, and fiber breakage appeared. These results indicated that after puncturing lateral annulus fibrosus and aspirating the nucleus pulposus, radiograph height of the intervertebral disc and MRI T2-weighted signal intensity gradual y reduced. Pathological changes were observed. However, the degeneration al eviated between 8-12 weeks.

In the context of the rapid development of big data in the healthcare field, deep learning (DL), as a machine learning algorithm that provides a more flexible solution for image and speech recognition as well as natural language processing, has the ability to extract important information from medical data into valuable knowledge and it has received unprecedented attention in many real-world tasks. This paper briefly introduces common network structure of deep learning and its latest research progress in the field of medical laboratory. In addition, this review also exploreed some of the inherent challenges and prospective research directions about deep learning that affecting in the medical laboratory.

OBJECTIVE: To evaluate the application of surgical strategies for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving the C ₂ segment. METHODS: The literature about the surgery for cervical OPLL involving C ₂ segment was reviewed, and the indications, advantages, and disadvantages of surgery were summarized. RESULTS: For cervical OPLL involving the C ₂ segments, laminectomy is suitable for patients with OPLL involving multiple segments, often combined with screw fixation, and has the advantages of adequate decompression and restoration of cervical curvature, with the disadvantages of loss of cervical fixed segmental mobility. Canal-expansive laminoplasty is suitable for patients with positive K-line and has the advantages of simple operation and preservation of cervical segmental mobility, and the disadvantages include progression of ossification, axial symptoms, and fracture of the portal axis. Dome-like laminoplasty is suitable for patients without kyphosis/cervical instability and with negative R-line, and can reduce the occurrence of axial symptoms, with the disadvantage of limited decompression. The Shelter technique is suitable for patients with single/double segments and canal encroachment >50% and allows for direct decompression, but is technically demanding and involves risk of dural tear and nerve injury. Double-dome laminoplasty is suitable for patients without kyphosis/cervical instability. Its advantages are the reduction of damage to the cervical semispinal muscles and attachment points and maintenance of cervical curvature, but there is progress in postoperative ossification. CONCLUSION OPLL involving the C ₂ segment is a complex subtype of cervical OPLL, which is mainly treated through posterior surgery. However, the degree of spinal cord floatation is limited, and with the progress of ossification, the long-term effectiveness is poor. More research is needed to address the etiology of OPLL and to establish a systematic treatment strategy for cervical OPLL involving the C ₂ segment.
Humans ; Longitudinal Ligaments/surgery* ; Ossification of Posterior Longitudinal Ligament/surgery* ; Treatment Outcome ; Osteogenesis ; Decompression, Surgical/methods* ; Cervical Vertebrae/surgery* ; Laminoplasty/methods* ; Kyphosis/surgery* ; Retrospective Studies