Object: The dorsal root ganglion (DRG) should not be overlooked when considering the mechanism of low-back pain and sciatica, so it is important to understand the morphological features of the vascular system supplying the DRG. However, the neurogenic control of intraganglionic blood flow has received little attention in the past. The authors used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerves in blood vessels of the DRG.Methods: Ten Wistar rats were used. To investigate the mechanism of vasomotion on the lumbar DRG, the authors used immunohistochemical methods. Sections were incubated overnight with antisera to tyrosine hydroxylase (TH), aromaticl-amino-acid decarboxylase (AADC), 5-hydroxytryptamine, substance P (SP), calcitonin gene–related peptide (CGRP), vasoactive intestinal peptide (VIP), somatostatin (SOM), neuropeptide Y (NPY), leucine-enkephalin, and cholineacetyl transferase (Ch-E). The avidin-biotin complex method was used as the immunohistochemical procedure, and the sections were observed under a light microscope.Results: In the immunohistochemical study, TH-, AADC-, SP-, CGRP-, VIP-, SOM-, NPY-, and Ch-E–positive fibers were seen within the walls of blood vessels in the DRG. This study revealed the existence of a comprehensive perivascular adrenergic, cholinergic, and peptidergic innervation of intraganglionic blood vessels, with a possible role in neurogenic regulation (autoregulation) of intraganglionic circulation.Conclusions: The presence of perivascular nerve plexuses around intraganglionic microvessels suggests that autonomic nerves play an important role in intraganglionic circulation.

Study Design.: Histological, immunohistochemical, and suspension array analyses of cytokine expression in human cervical ossification of the posterior longitudinal ligament (OPLL). Objectives.: The aim of this study was to determine whether changes in the cytokine profile reflect the maturation of chondrocytes and osteoblasts are associated with OPLL development. Summary of Background Data.: OPLL progresses gradually over a prolonged period and may lead to serious spinal cord complications. However, treatment methods only include conservative therapy for neurological symptoms or surgical decompression, whereas preventive therapy for OPLL remains nonexistent. Methods.: Ligamentous samples were harvested from 24 patients with OPLL who underwent spinal surgery, and five control samples from cervical spondylotic myelo/radiculopathy patients without OPLL. Tissue sections were used for immunohistochemical studies and primary cells were cultured from the ligamentous samples for cytokine profiling. Using a suspension array system, concentrations of 27 inflammatory cytokines or growth factors were measured to generate the cytokine profiles. Results.: Suspension array and immunoblot analysis revealed significant increments in the levels of interleukin (IL)-6, IL-1α, basic fibroblast growth factor, and RANTES in patients with OPLL. Immunohistochemical analysis further revealed that these factors were present in mesenchymal cells within the degenerative portion of the ligamentous matrix. Conclusion.: Our findings suggest that specific changes in the cytokine profile during ossification promote osteoblast differentiation, thereby providing new insights into OPLL pathogenesis. Moreover, this work supports the development of a new therapeutic method for preventing OPLL progression by regulating the cytokine profiles. Level of Evidence: 3

Purpose: Rheumatoid arthritis (RA) patients with secondary osteoarthritis (OA) in a knee joint following a total knee arthroplasty (TKA) procedure have been increasing. Here, we investigated osteophyte formation in knee joints of RA patients and associated factors. Methods: We retrospectively examined findings of 35 knees in 30 RA patients (26 females, 4 males; mean age: 63.0 years; median disease duration: 15 years) who underwent TKA, including preoperative anteroposterior view radiographs of the knee joint. Using the ImageJ software package, osteophyte size in the medial femur (MF), medial tibia (MT), lateral femur (LF), and lateral tibia (LT) regions was also determined. Results: The mean femorotibial angle was 179°, while Larsen grade was 2 in 1, 3 in 12, 4 in 18, and 5 in 2 patients. Osteophyte sizes in the MF, MT, LF, and LT regions were 37.2, 17.0, 27.2, and 4.57 mm², respectively, and significantly greater in the medial compartment (MC; MF+MT) than the lateral compartment (LC; LF+LT) ( p < 0.001). In varus cases, osteophyte size in the MC was significantly larger than normal and valgus cases ( p = 0.0016). Furthermore, osteophyte size in the MC was negatively correlated with the inflammatory markers C-reactive protein ( r = −0.492, p = 0.0027) and erythrocyte sedimentation rate ( r = −0.529, p = 0.0016), whereas that in the LC was negatively correlated with disease activity ( r = −0.589, p = 0.0023). Conclusion: Our results suggest that alignment and disease activity influence osteophyte formation in RA patients, with secondary OA a more prominent symptom in RA patients with controlled inflammation.