Study Design. To identify and characterize endogenous progenitor cell population from intervertebral disc. Objective. To determine if progenitor cells exist in degenerate human discs. Summary of Background Data. Back pain, a significant source of morbidity in our society, is directly linked to the pathology of the intervertebral disc. Because disc disease is accompanied by a loss of cellularity, there is considerable interest in regeneration of cells of both the anulus fibrosus (AF) and nucleus pulposus (NP). Methods. To determine if skeletal progenitor cells are present in the disc, samples were obtained from the degenerate AF and NP of 5 patients (Thompson grade 2 and 3, mean age 34 ± 7.6 years) undergoing anterior cervical discectomy and fusion procedures as well as adult rat lumbar spine. Results. Cells isolated from degenerate human tissues expressed CD105, CD166, CD63, CD49a, CD90, CD73, p75 low affinity nerve growth factor receptor, and CD133/1, proteins that are characteristic of marrow mesenchymal stem cells. In osteogenic media, there was an induction of alkaline phosphatase activity and expression of alkaline phosphatase, osteocalcin, and Runx-2 mRNA. When maintained in adipogenic media, a small percentage of cells displayed evidence of adipogenic differentiation: accumulation of cytosolic lipid droplets and increased expression of peroxisome proliferator-activated receptor-γ2 and lipoporotein lipase mRNA. AF- and NP-derived cells also evidenced chondrogenic differentiation. CD133 (+) cells in the AF were able to commit to either the chondrogenic or adipogenic lineages. The results of the human disc studies were confirmed using cell derived from the NP and AF tissue of the mature rat disc. Conclusion. The analytical data indicated that the pathologically degenerate human disc contained populations of skeletal progenitor cells. These findings suggest that these endogenous progenitors may be used to orchestrate the repair of the intervertebral disc.

Immune interferon (IFN), also known as IFN-γ, promotes not only immunomodulation but also antimicrobial and anticancer activity. After IFN-γ binds to the complex of IFN-γ receptor (IFNGR) 1-IFNGR2 and subsequently activates its downstream signaling pathways, IFN-γ immediately causes transcriptional stimulation of a variety of genes that are principally involved in its biological activities. Regarding IFN-γ-dependent immunosurveillance, IFN-γ can directly suppress tumorigenesis and infection and/or can modulate the immunological status in both cancer cells and infected cells. Regarding the anticancer effects of IFN-γ, cancer cells develop strategies to escape from IFN-γ-dependent cancer immunosurveillance. Immune evasion, including the recruitment of immunosuppressive cells, secretion of immunosuppressive factors, and suppression of cytotoxic T lymphocyte responses, is speculated to be elicited by the oncogenic microenvironment. All of these events effectively downregulate IFN-γ-expressing cells and IFN-γ production. In addition to these extrinsic pathways, cancer cells may develop cellular tolerance that manifests as hyporesponsiveness to IFN-γ stimulation. This review discusses the potential escape mechanisms from IFN-γ-dependent immunosurveillance in tumorigenesis.

The complex process of wound healing depends on the coordinated interaction between various immunological and biological systems, which can be aided by technology. This present review provides a broad overview of the medical applications of piezoelectric and triboelectric nanogenerators, focusing on their role in the development of wound healing technology. Based on the finding that the damaged epithelial layer of the wound generates an endogenous bioelectric field to regulate the wound healing process, development of technological device for providing an exogenous electric field has therefore been paid attention. Authors of this review focus on the design and application of piezoelectric and triboelectric materials to manufacture self-powered nanogenerators, and conclude with an outlook on the current challenges and future potential in meeting medical needs and commercialization. Grpahical Abstract

A retrospective study assessing the long-term outcomes of repeat surgery for recurrent lumbar disc herniation. To evaluate the results of repeat surgery for recurrent disc herniation, and compare the results of disc excision with and without posterolateral fusion. The outcomes of revision surgery varied owing to the mixed patient populations. The optimal technique for treating recurrent disc herniation is controversial. The sample included 41 patients who underwent disc excision with or without posterolateral fusion, with an average follow-up of 88.7 months (range, 60–134 months). Clinical symptoms were assessed based on the Japanese Orthopedic Association Back Scores. All medical and surgical records were examined and analyzed, including pain-free interval, intraoperative blood loss, length of surgery, and postsurgery hospital stay. Clinical outcome was excellent or good in 80.5% of patients, including 78.3% of patients undergoing a discectomy alone, and 83.3% of patients with posterolateral fusion. The recovery rate was 82.2%, and the difference between the fusion and nonfusion groups was insignificant (P = 0.799). The difference in the postoperative back pain score was also insignificant (P = 0.461). These two groups were not different in terms of age, pain-free interval, and follow-up duration. Intraoperative blood loss, length of surgery, and length of hospitalization were significantly less in patients undergoing discectomy alone than in patients with fusion. Repeat surgery for recurrent sciatica is effective in cases of true recurrent disc herniation. Disc excision alone is recommended for managing recurrent disc herniation.

Lateral flow immunoassays (LFIAs) have wide application in point-of-care testing, particularly in resource-poor settings. To achieve signal amplification in a gold nanoparticle-based lateral flow assay without an additional procedure or the need for complex fabrication, a new and simple method was developed for using a “stacking pad” configuration that adds an additional membrane between the conjugation pad and test pad to the conventional AuNP-based LFIA format. This design helps to accumulate the antibody and antigen on the stacking pad, hence extending the antigen/antibody binding interactions to enhance the test’s detection sensitivity. With the enhanced lateral flow assay, as low as 1 ng/mL of Protein A and 15.5 ng/mL of C-reactive protein can be visualized with the naked eye. We also successfully applied the stacking pad system in the analysis of C-reactive protein in human serum and synovial fluid samples. These results suggest that this stacking pad LFIA can provide sensitive and on-site prognosis for detection in synovial fluid and serum samples in resource-limited settings.