Referred pain: characteristics, possible mechanisms, and clinical management.

Purpose of this review: Referred pain is a common but less understood symptom that originates from somatic tissues. A comprehensive recognition of referred pain is important for clinicians when dealing with it. The purpose of this study is to summarize the current understanding of referred pain, including its pathogenesis, characteristics, diagnosis, and treatment. Recent findings: Referred pain arises not only from pathologies primarily involving local tissue but also from lesions in distant structures. Central sensitization of convergent neurons and peripheral reflexes of dichotomizing afferent fibers are two theories proposed to explain the pathological mechanism of referred pain. Because syndromes related to referred pain of different origins overlap each other, it is challenging to define referred pain and identify its originating lesions. Although various approaches have been used in the diagnosis and treatment of referred pain, including conservative treatment, blockade, radiofrequency, and surgery, management of referred pain remains a clinical challenge. Summary: Unlike radicular pain and neuropathic pain, referred pain is a less studied area, despite being common in clinics. Referred pain can derive from various spinal structures, and blockage helps identify the primary pathology. Due to the heterogeneity of referred pain, treatment outcomes remain uncertain. Further studies are needed to improve our understanding of referred pain.

Sensory innervation of the lumbar 5/6 intervertebral disk in mice.

Introduction: Over the years, most back pain-related biological studies focused on the pathogenesis of disk degeneration. It is known that nerve distributions at the outer layer of the annulus fibrosus (AF) may be an important contributor to back pain symptoms. However, the types and origins of sensory nerve terminals in the mouse lumbar disks have not been widely studied. Using disk microinjection and nerve retrograde tracing methods, the current study aimed to characterize the nerve types and neuropathway of the lumbar 5/6 (L5/6) disk in mice. Methods: Using an anterior peritoneal approach, the L5/6 disk of adult C57BL/6 mice (males, 8-12 weeks) disk microinjection was performed. Fluorogold (FG) was injected into the L5/6 disk using the Hamilton syringe with a homemade glass needle driven by a pressure microinjector. The lumbar spine and bilateral thoracic 13 (Th13) to L6 DRGs were harvested at 10 days after injection. The number of FG+ neurons among different levels was counted and analyzed. Different nerve markers, including anti-neurofilament 160/200 (NF160/200), anti-calcitonin gene-related peptide (CGRP), anti-parvalbumin (PV), and anti-tyrosine hydroxylase (TH), were used to identify different types of nerve terminals in AF and their origins in DRG neurons. Results: There were at least three types of nerve terminals at the outer layer of L5/6 AF in mice, including NF160/200+ (indicating Aß fibers), CGRP+ (Aδ and C fibers), and PV+ (proprioceptive fibers). No TH+ fibers (sympathetic nerve fibers and some C-low threshold mechanoreceptors) were noticed in either. Using retrograde tracing methods, we found that nerve terminals in the L5/6 disk were multi-segmentally from Th13-L6 DRGs, with L1 and L5 predominately. An immunofluorescence analysis revealed that FG+ neurons in DRGs were co-localized with NF160/200, CGRP, and PV, but not TH. Conclusion: Intervertebral disks were innervated by multiple types of nerve fibers in mice, including Aß, Aδ, C, and proprioceptive fibers. No sympathetic nerve fibers were found in AF. The nerve network of the L5/6 disk in mice was multi-segmentally innervated by the Th13-L6 DRGs (mainly L1 and L5 DRGs). Our results may serve as a reference for preclinical studies of discogenic pain in mice.

A deep learning approach for medical waste classification.

As the demand for health grows, the increase in medical waste generation is gradually outstripping the load. In this paper, we propose a deep learning approach for identification and classification of medical waste. Deep learning is currently the most popular technique in image classification, but its need for large amounts of data limits its usage. In this scenario, we propose a deep learning-based classification method, in which ResNeXt is a suitable deep neural network for practical implementation, followed by transfer learning methods to improve classification results. We pay special attention to the problem of medical waste classification, which needs to be solved urgently in the current environmental protection context. We applied the technique to 3480 images and succeeded in correctly identifying 8 kinds of medical waste with an accuracy of 97.2%; the average F1-score of five-fold cross-validation was 97.2%. This study provided a deep learning-based method for automatic detection and classification of 8 kinds of medical waste with high accuracy and average precision. We believe that the power of artificial intelligence could be harnessed in products that would facilitate medical waste classification and could become widely available throughout China.

Clinical Analysis of Causes and Countermeasures of Hand Injury During the COVID-19 Outbreak and Work Resumption Period: A Retrospective Study in a Designated Hospital in China.

A total of 95 patients with hand injuries were admitted to the orthopedics department within half a year of the COVID-19 outbreak. Data were collected between January 23, 2020 and July 23, 2020. Data such as patients' demographics, type of injury, location, side of lesions, mechanism of injury, injury site, and surgical management were collected and subsequently analyzed. On the one hand, the total number of emergency visits due to hand injury during the COVID-19 outbreak decreased by 37%, compared to the same period in the previous year. On the other hand, work resumption injuries increased by 40%. Injuries within the resumption period occurred predominantly at work (64.7%) and were significantly higher than the same period in 2019 (37.3%) (P < .001). Machine-related injuries were the most frequent injuries seen in our hospital (58.8%). The majority of cases were from cut injuries (82.4%), with fingers being the most common site of these injuries. Simple fractures and dislocations were also reported during the study. Most injuries were classified as either minor or moderate (90%) during the outbreak. However, during the resumption of work, major injuries were more prevalent (40%). The proportion of major injuries this year's work resumption stage (40%) has almost doubled compared to the previous year (21.8%, P = .006). The resumption of work following the COVID-19 outbreak is a time of high-risk for hand injuries. The overall number of patients with hand injuries admitted into our department has decreased compared to the corresponding period last year. However, workplace injuries, particularly machine-related ones, considerably increased during the first six months after the COVID-19 outbreak. As a result, the proportion of major injuries drastically increased. Emergency and surgical health care providers should be aware of this pattern of hand injuries during this untypical time in order to effectively prepare and plan services.

Restoration of forearm supination by combining pronator teres with allogeneic tendon.

BACKGROUND: Many solutions have been proposed in treating of forearm supination. Comparing with other supination function reconstructions, pronator teres rerouting is believed to be less effective due to its insufficient supination strength. The aim of this study is to introduce a modified procedure, and compare its result with two previous approaches. PATIENTS AND METHODS: From 2015 to 2020, 11 patients have restored forearm supination by rerouting of the pronator teres weave sutured with allogeneic tendons. The average follow-up period was 17.5 months (12 to 24). The range of active supination at the final follow-up was recorded. RESULTS: Almost all patients acquired good supination range. The average active post-operative supination was 72.7° (60° to 80°) at the final follow-up. No complication was observed. All patients retained full range of pronation. CONCLUSIONS: This study provides a modified supination function reconstruction with simple operating, fine results, low risks, and no affecting of pronation function. The use of allogeneic tendon makes up for the muscles with insufficient length, making it valuable to reconsider those rebuilding operations that were once considered unpromising by many.

Intramuscular tumoral calcinosis near the arteriovenous fistula mimicking acute infection.

Tumoral calcinosis is a kind of tumorous calcified masses, which may progress in patients with chronic renal failure. Uremic tumoral calcinosis in the brachioradialis muscle presented like acute infection of the arteriovenous fistula has not been previously reported. A 49-year-old man came to our hospital with a 9-year history of hemodialysis and secondary hyperparathyroidism. He had a huge painful mass in the left forearm at admission. The treatment was debridement and cytoreductive surgery accompanied by parathyroidectomy and medical management of calcium phosphate imbalance. After the comprehensive treatment, the patient recovered from his previously affected forearm. This is an enlightening case of intramuscular tumoral calcinosis mass that presented mimicking the infection of the arteriovenous fistula. Nephrologists and surgeons should pay attention to early diagnosis and proper management of the primary disease to master the indication and opportunity of resection.

Exposure risk of patients with chronic infectious wounds during the COVID-19 outbreak and its countermeasures.

BACKGROUND: A large number of cases of pneumonia caused by novel ß-coronavirus emerged in Hubei Province, China, at the end of 2019 and demonstrated great potential for transmission. At present, known independent risk factors include age, diabetes, and other chronic diseases, which may be similar to the patients with chronic wound; thus, we try to explore the clinical characteristics, prognostic factors, and management recommendation of patients with chronic infective wounds during the COVID-19 epidemic period. METHODS: In this single-center, retrospective observational study, we included all cases with chronic infective wounds that came to our hospital between the full outbreak of the COVID-19 in China (January 23, 2020) and the latest date prior to posting (20 April 2020). Demographic data, comorbidities, laboratory and imaging findings, consultation history, and clinical outcomes (lesion cured, uncontrolled, amputated, etc. as of May 10, 2020) were collected for all individuals. Patients were subdivided into gangrene, traumatic infection, and other types of soft tissue infection wound (including bedsores, gout ruptures, stab wounds, and so on) according to the causes of wound, and their disease-related information were compared group by group. RESULTS: Among the total 81 patients with chronic infective wounds, 60% were male, with a mean age of 60.8 years (SD 18.6), including 38 (47%) patients with traumatic infection, 29 (36%) gangrene cases, and 14 (17%) other soft tissue infection wounds. Common comorbidities are hypertension (32%), diabetes (32%), cardiovascular disease (24%), and kidney injury (12%), and the patients with gangrenes have the most comorbidities. As of May 10, 2020, there were 78 patients discharged, and their average stay time is 15.8 days (SD 14.2), while people still at the hospital is 39.7 days (SD 8.7) much longer than the discharged and also has more comorbidities. But there is no significant difference in the hospitalization time of three types of wounds. And fortunately, none of all the patients were infected by coronavirus. CONCLUSION: The majority of patients with chronic wounds are severely ill with high risk of infection and poor prognosis; therefore, management of patients with chronic wounds should be improved.

Infiltration of synovitis into the flexor tendon: a case report.

Synovitis is a type of aseptic inflammation that occurs within joints or surrounding tendons. No previous reports have described a hypertrophic synovium eroding the tendon sheath and manifesting as synovitis within the flexor tendon. We herein report a case involving a 10-year-old girl who presented to our hospital with a 1-month history of a swollen mass and progressive inability to completely flex her left index finger. The active flexion angle of the proximal interphalangeal joint was limited to 85°. A longitudinal incision of the flexor digitorum profundus tendon was surgically performed. The synovium inside and outside the flexor digitorum profundus tendon was completely removed. After the surgical excision, normal tendon gliding returned without recurrence by the 1-year follow-up. The active flexion angle of the proximal interphalangeal joint improved to 100°. To the best of our knowledge, this is the first case of synovitis affecting the flexor tendon and leading to limited flexion of a finger. The manifestation of a double ring sign on magnetic resonance imaging is quite characteristic. Early diagnosis and monitoring of the hyperproliferation and invasiveness of the synovial tissue are required. Surgical excision can be a simple and effective tool when necessary.

Angioleiomyoma of the hand with nerve compression.

OBJECTIVE: This study was performed to analyze the clinical, radiographic, and pathological features of hand angioleiomyoma causing nerve compression and assess the outcomes of surgical excision. METHODS: This case series included three men and one woman (mean age, 53.3 years; range, 49-56 years). The patients' chief complaint was numbness of the fingers. The patients' medical histories were reviewed, and the diagnosis of angioleiomyoma with nerve compression was confirmed by means of imaging examination and pathological analysis. RESULTS: Three tumors occurred in the palm and one in the finger, and the average maximum tumor diameter was 1.8 cm (range, 0.8-2.6 cm). Preoperative magnetic resonance imaging demonstrated well-defined masses with isointense signals on T1 sequences, hyperintense signals on T2 sequences, and strong heterogeneous enhancement after injection of contrast material. All tumors were located near nerves, leading to nerve compression. The diagnosis of angioleiomyoma was confirmed by postoperative pathology. Finger sensation recovered and no recurrence was found during an average follow-up of 37 months (range, 25-59 months). CONCLUSIONS: Angioleiomyoma should be considered among the differential diagnoses of hand tumors and timely resection should be performed, particularly if the mass is causing numbness and/or pain with positive Tinel's sign and/or tenderness.

14-3-3σ downregulation suppresses ICC metastasis via impairing migration, invasion, and anoikis resistance of ICC cells.

BACKGROUND: 14-3-3σ protein plays an important role in multiple cellular processes. The role of 14-3-3σ in the progression of intrahepatic cholangiocarcinoma (ICC) has not been well understood. OBJECTIVE: We performed this research to explore the relationship between 14-3-3σ level and clinical characteristics and prognosis of ICC patients. Besides, we used ICC cell lines HCCC-9810 and RBE to assess the biological function of 14-3-3σ. METHODS: We examined 14-3-3σ expression in 28 ICC tissues and matched paratumor tissues by quantitative real-time PCR and immunohistochemistry. Additionally, ICC tissue array from 100 patients and normal liver tissue array from 24 healthy people were also analyzed by immunohistochemistry. 14-3-3σ was knocked down in ICC cell lines and the functions and mechanisms of 14-3-3σ were assessed. RESULTS: 14-3-3σ is highly expressed in ICC tissues and high expression of 14-3-3σ correlates poor overall survival in ICC patients. Knocking down of 14-3-3σ in ICC cell lines reduced cells migration, invasion and anoikis resistance. Furthermore, 14-3-3σ-silenced ICC cells showed significantly decreased invasion-related protein MMP2 and MMP9 expression. CONCLUSIONS: Our results demonstrate prognostic value of 14-3-3σ and its role in metastasis, which is associated with ICC cell lines migration, invasion and anoikis resistance.