Facilitatory effects of artificial nerve filled with adipose-derived stem cell sheets on peripheral nerve regeneration: An experimental study.

BACKGROUND: We evaluated how artificial nerves filled with adipose-derived stem cell (ADSC) sheets could facilitate peripheral nerve regeneration. METHODS: We prepared ADSC sheets following previously described protocols. We transected the sciatic nerve in 12-week-old Wistar rats, fixed the nerve ends to the artificial conduit, and prepared three groups: (1) conduits alone (control group); (2) conduits filled with ADSCs (ADSCs group), and (3) conduits filled with ADSC sheets (ADSC sheet group). We assessed the subjects 4 and 12 weeks post-transplantation (n = 24). We investigated ßIII-tubulin and anti-S100 expression at 4 and 12 weeks post-transplantation, in longitudinal- and cross-sections of the central portion in the regenerated tissues. The vascular endothelial growth factor A (VEGFA) and neuregulin-1 expressions were analyzed using real-time reverse-transcription polymerase chain reaction (real-time RT-PCR). We evaluated the tibialis anterior muscle wet weight (affected/healthy sides, %) and sciatic function index (SFI) 12 weeks post-transplantation. RESULTS: The ADSC sheet group comprised more S100-positive cells than the other groups. The regenerated axon length in the ADSC sheet group was markedly the longest among the studied groups. The immunostaining revealed a positive area in the regenerated tissue center in all groups, tending to be the largest in the ADSC sheet group. The muscle wet weight indicated that the ADSC sheet group exhibited significantly higher weight than the control. The mean SFI showed that the ADSC sheet group exhibited significantly better results than the control. The VEGFA expression was higher both in the ADSC and the ADSC sheet group than in the control. The neuregulin-1 expression was higher both in the ADSC and the ADSC sheet group than in the control. CONCLUSIONS: The ADSC sheets could potentially support transplanting an adequate number of ADSCs at the target site. Compared with the conventional method of attaching ADSCs, the use of ADSC sheets promotes accelerated nerve regeneration.

Differentiated adipose-derived stem cells promote peripheral nerve regeneration.

INTRODUCTION: Many reports have indicated that adipose-derived stem cells (ADSCs) are effective for nerve regeneration. We investigated nerve regeneration by combining a polyglycolic acid collagen (PGA-c) tube, which is approved for clinical use, and Schwann cell-like differentiated ADSCs (dADSCs). METHODS: Fifteen-millimeter-long gaps in the sciatic nerve of rats were bridged in each group using tubes (group I), with tubes injected with dADSCs (group II), or by resected nerve (group III). RESULTS: Axonal outgrowth was greater in group II than in group I. Tibialis anterior muscle weight revealed recovery only in group III. Latency in nerve conduction studies was equivalent in group II and III, but action potential was lower in group II. Transplanted dADSCs maintained Schwann cell marker expression. ATF3 expression level in the dorsal root ganglia was equivalent in groups II and III. DISCUSSION: dADSCs maintained their differentiated state in the tubes and are believed to have contributed to nerve regeneration.

The impact of economic uncertainty caused by COVID-19 on renewable energy stocks.

By employing time-frequency-domain frameworks, this study analyzes the spillover effects of news-based economic uncertainty caused by the pandemic on three renewable energy stock indices in the USA, Europe, and the world. The empirical results reveal that the total spillover from economic uncertainty to the three renewable energy stock returns was concentrated at a high frequency, whereas those to volatilities appeared at low frequencies. Utilizing a rolling-window method, we observed that the impact of uncertainty caused by COVID-19 on three renewable energy stock returns and volatilities is more significant than that resulting from the global financial crisis (GFC). During COVID-19, the majority of the spillover effects from economic uncertainty to returns and volatilities of the three indices focused on the long term.

Case Report: Prophylactic Plate Fixation for Incomplete Atypical Ulnar Fractures Resulting From the Use of Denosumab for Bone Metastases.

Patients with bone metastases are treated with long-term bone resorption inhibitors such as bisphosphonates and denosumab. However, resorption inhibitors have been known to cause fractures, such as atypical femoral fractures (AFFs). In recent years, there have been an increasing number of reports of atypical ulna fractures (AUFs) caused by bone resorption inhibitor usage. Treatment of AUFs is complicated, especially when they occur in patients with bone metastases, because it is difficult to discontinue bone resorption inhibitor treatment without the risk of aggravating metastatic lesions. Prophylactic surgery is recommended in AFFs when fractures are predicted, but there are few reports of prophylactic surgery for AUFs. Here, we report a case of incomplete AUF in a 74-year-old woman which was surgically treated with prophylactic plate fixation. The patient had been using denosumab for 6 years to treat bone metastases due to thyroid cancer. After surgery, no fractures were observed for 2 years without discontinuing denosumab, and her forearm function was adequate. AUFs are rare and difficult to treat, so oncologists who treat bone metastases need to pay special attention to diagnose this incomplete AUF before the fracture worsens. We believe that detection of a possible fracture and prophylactic surgery can improve prognosis.

Two Cases of Morel-Lavallée Lesion Which Resulted in a Wide Skin Necrosis from a Small Laceration.

Morel-Lavallée lesion (MLL) is a degloving injury in soft tissues caused by shear force accompanying trauma. Even if it is a small lacrimal wound at the initial visit, there is a range of skin necrosis which is not suitable for it. As a cause of the injury, a shearing force was applied over a wide range, and penetrating blood vessel damage to the skin occurred, resulting in skin necrosis. Attention is required.

Preventive Effect of Alginate Gel Formulation on Perineural Adhesion.

Background: Perineural adhesion is a potential complication of manipulating peripheral nerves. Using a model of median nerve manipulation in the carpal tunnel, perineural adhesion preventive effects of an alginate gel formulation were examined. Methods: After exposing carpal tunnels of Japanese white rabbits and dissecting the median nerve, the gliding floor was excised as much as possible and the transverse carpal ligament was repaired to induce a perineural tissue reaction. Prior to wound closure, 0.5 ml of alginate gel formulation was administered into the right carpal tunnel (formulation group) and 0.5 ml of physiological saline was administered into the left carpal tunnel (control group). At 1, 2, 3, and 6 weeks after treatment, electrophysiological evaluation of thenar distal latency, macroscopic evaluation with adhesion score, and pathological evaluation of carpal tunnel cross sections were performed (N = 4-5 at each time point). Results: Although distal latency tended to be low in the formulation group, there was no significant difference between the groups according to electrophysiological evaluation. Macroscopic evaluation revealed that the adhesion score was always lower in the formulation group than in the control group; over the course of treatment, it remained unchanged in the formulation group, but peaked at 3 weeks after treatment in the control group. In pathological evaluation, neural perfusion peaked at 2-3 weeks after treatment in both groups; neural perfusion tended to be lower in the formulation group than in the control group. Conclusions: Results suggested that the peak tissue response associated with nerve dissection occurred 2-3 weeks after treatment and that the repair process started subsequently. The alginate gel formulation modified the surrounding environment of the nerve and promoted repair by acting as a physical barrier against perineural fibrosis. The preventive effect of alginate gel on perineural adhesion may improve treatment outcomes of constrictive neuropathy.

Topical Application of Fasudil Hydrochloride for Vasospasm during Soft Tissue Reconstruction Using a Free Flap.

Vasospasm is a phenomenon that can complicate microsurgery. We report a case in which vasospasm was quickly relieved by topical application of fasudil hydrochloride. A 36-year-old man underwent preoperative chemotherapy and wide excision for a malignant soft tissue tumor around the knee joint. We planned reconstruction using a free latissimus dorsi muscle flap for the resulting soft tissue defect and selected the peroneal vessels as the recipient vessels. However, there was no arterial blood flow from the peroneal vessels, which we diagnosed as vasospasm. Conventional treatment of the vasospasm was attempted, but blood flow was not achieved. Topical application of fasudil hydrochloride solution promptly relieved the vasospasm. To the best of our knowledge, this is the first clinical report of the use of fasudil hydrochloride for vasospasm during soft tissue reconstruction using a free flap.

Tin Ring Splint Treatment for Osteoarthritis of the Distal Interphalangeal Joints.

Background: We made a tin ring splint for osteoarthritis of the distal interphalangeal joint that looks attractive and is easy to wear. We report the treatment results with this splint. Methods: We enrolled 30 patients with painful osteoarthritis of the distal interphalangeal joint in this study. A tin ring splint was made with tin alloy containing small quantities of silver. Patients were instructed to wear the splint when they felt pain. Patients were assessed before splint use and after 1, 3, and 6 months of splint use. Endpoints included the numeric pain scale, active arc of motion of the distal interphalangeal joint, Hand 20, functional assessment criteria of the upper extremities, and treatment satisfaction. In addition, data were collected on time to symptom relief and satisfaction related to usability and appearance of the splint (0 = dissatisfied, 10 = satisfied). Results: The numeric pain scale showed significant pain improvement from 58.4 ± 4.1 at baseline to 33.1 ± 4.5 at 1 month, and the Hand 20 score also showed significant improvement from 35.0 ± 4.3 at baseline to 20.2 ± 3.2 after 6 months. Active arc of motion were not changed significantly. Most patients responded that symptoms were relieved by the 10th day after treatment. Satisfaction related to usability was 8.9 ± 0.3, and appearance was 7.6 ± 0.4. Conclusions: A tin ring splint quickly reduced pain, and satisfaction related to usability and appearance was high. This splint could be one choice for conservative treatment of osteoarthritis of the distal interphalangeal joint.

A Case of a 5-Year-Old Boy with a Blauth Type IIIB Hypoplastic Thumb Reconstructed with a Nonvascularized, Hemilongitudinal Metatarsal Transfer.

The treatment methods used for Blauth type IIIB hypoplastic thumbs are controversial. We performed a nonvascularized, hemilongitudinal metatarsal bone transfer on a 5-year-old boy with a type IIIB hypoplastic thumb. Despite the child's age, the growth of the thumb was confirmed and the thumb had stabilized. Moreover, growth disorder of the donor toe was not observed. This method is relatively easy to perform. And donor toe deformation can be prevented, because of the preservation of more than half of the metatarsal bone. In our case, the patient was 5 years of age; nevertheless, the epiphyseal line was opened and the grafted metatarsal bone grew. This method is useful in terms of its simplicity and prevention of postoperative complications.