Finding a Needle in the Haystack: Design and Implementation of a Digital Site-less Clinical Study of Serial Rapid Antigen Testing to Identify Asymptomatic SARS-CoV-2 Infection

BackgroundOver-the-counter rapid antigen tests for SARS-CoV-2 with an Emergency Use Authorization (EUA) in the United States generally include a condition of authorization to evaluate the tests performance in asymptomatic individuals when used serially. A goal of this study was to investigate the performance of SARS-CoV-2 antigen serial testing and generate data to support regulatory decisions. ObjectiveTo describe a novel study design to evaluate serial use of rapid antigen tests in detecting SARS-CoV-2 virus among asymptomatic individuals. DesignProspective cohort study using a decentralized approach. Eligible participants from across the U.S. could enroll and complete this study from their home environment through a study app. Participant enrollment was prioritized based on regional 7-day case rates, participants vaccination status, and sociodemographic characteristics prior to enrollment. Prioritization criteria were adjusted on a daily or weekly basis. Enrolled participants were mailed rapid antigen tests and molecular comparator collection kits and asked to test every 48 hours for 15 days. Three companies rapid antigen tests were used in the study; assignment of participant to a test was criteria-based and non-random, precluding head-to-head comparison between the tests. ParticipantsMainland United States residents over 2 years old with no reported COVID-19 symptoms in the 14 days prior to study enrollment. Main MeasuresParticipant demographics, COVID-19 vaccination status, and geographic distribution were used to understand the impact of the site-less recruitment and enrollment strategy. Key ResultsA total of 7,361 participants enrolled in the study between October 18, 2021 and February 15, 2022. Throughout the study, 369 participants tested positive for SARS-CoV-2, including 167 who were asymptomatic and tested negative on SARS-CoV-2 molecular assays to start the study. This exceeded the initial enrollment goals of 60 positive participants. We enrolled participants from 44 of the 48 mainland U.S. states, and geographic distribution of participants shifted in accordance with the changing COVID-19 prevalence nationwide. ConclusionsThe novel, digital site-less approach employed in the Test Us At Home study enabled rapid, efficient, and rigorous evaluation of rapid diagnostics for COVID-19, and can be adapted across research disciplines to optimize study enrollment and accessibility.

Using RNA-Seq to Explore the Repair Mechanism of the Three Methods and Three-Acupoint Technique on DRGs in Sciatic Nerve Injured Rats.

Objective: To study the effects of the three methods and three-acupoint technique on DRG gene expression in SNI model rats and to elucidate the molecular mechanism of the three methods and three-acupoint technique on promoting recovery in peripheral nerve injury. Methods: 27 male SD rats were randomly divided into three groups: a Sham group, the SNI group, and the Tuina group. The Tuina group was treated with a tuina manipulation simulator to simulate massage on points, controlling for both quality and quantity. Point-pressing, plucking, and kneading methods were administered quantitatively at Yinmen (BL37), Chengshan (BL57), and Yanglingquan (GB34) points on the affected side once a day, beginning 7 days after modeling. Intervention was applied once a day for 10 days, then 1 day of rest, followed by 10 more days of intervention, totally equaling 20 times of intervention. The effect of the three methods and three-point technique on the recovery of injured rats was evaluated using behavior analysis. RNA sequencing (RNA-Seq) analysis of differentially expressed genes in DRGs of the three groups of rats was also performed. GO and KEGG enrichment was analyzed and verified using real-time PCR. Results: RNA-Seq combined with database information showed that the number of differentially expressed genes in DRG was the largest in the Tuina group compared with the SNI group, totaling 226. GO function is enriched in the positive regulation of cell processes, ion binding, protein binding, neuron, response to pressure, response to metal ions, neuron projection, and other biological processes. GO function is also enriched in the Wnt, IL-17, and MAPK signaling pathways in the KEGG database. PCR results were consistent with those of RNA sequencing, suggesting that the results of transcriptome sequencing were reliable. Conclusion: The three methods and three-acupoint technique can promote the recovery of SNI model rats by altering the gene sequence in DRGs.

Clinics in diagnostic imaging (200). Intra-articular chronic tophaceous gout of the knee

A 39-year-old man presented with acute left knee pain and swelling. There was limitation of movement of the knee joint. His past medical history was significant for gout. Computed radiography showed bony erosions that were not typical of chronic tophaceous gout. Magnetic resonance (MR) imaging showed focal deposits within the knee joint, which demonstrated isointense signal to muscle on T1-weighted sequence and intermediate signal on proton density (PD) and PD fat-saturated sequences. There was extensive, similar signal abnormality in the cruciate ligaments, popliteus tendon and lateral meniscus. These findings were in keeping with an intra-articular manifestation of chronic tophaceous gout. The clinical presentation and imaging features are herein discussed, with an emphasis on MR imaging.

Clinics in diagnostic imaging (202). Osgood-Schlatter disease (OSD)

A 14-year-old boy presented with left anterior knee pain, which was aggravated by exercise and relieved by rest. On clinical examination, there was tenderness at the tibial tuberosity with reproducible pain on resisted active extension of the knee. Radiographs showed heterotopic ossification of the patellar tendon with irregularity and fragmentation of the tibial tubercle. Clinical and radiological findings were consistent with Osgood-Schlatter disease, which is a traction apophysitis of the tibial tubercle commonly occurring in adolescents. The clinical presentation and imaging features are discussed.

Clinics in diagnostic imaging (195). Plantar fibromatosis

A 46-year-old man presented with a six-month history of lumps in the sole of his left foot. Physical examination revealed two nodules, one tender and one firm, at the plantar left foot with no overlying skin changes. Although the initial radiographs were normal, magnetic resonance imaging of the left foot demonstrated two nodules along the medial band of the plantar fascia, characteristic of plantar fibromas. The patient opted for surgical excision. There was no further recurrence of symptoms after surgery. We describe the clinical and radiological features of plantar fibromatosis and briefly discuss other causes of lumps and pain in the sole of the foot.

Clinics in diagnostic imaging (192). Flexion teardrop fracture

An 82-year-old woman presented with neck pain and bilateral upper limb paraesthesia after sustaining an unwitnessed fall at home the day before. Physical examination revealed tenderness over the C4-6 region but no evidence of step deformity or neurological deficit. Magnetic resonance imaging of the cervical spine revealed multiple small fractures at the anteroinferior endplate corners of the C3, C5 and C6 vertebrae with focal kyphosis and marrow oedema at these levels, as well as associated disruption of the anterior longitudinal ligament and central spinal canal stenosis. The diagnosis of multiple flexion teardrop fractures was made based on these imaging findings, and the patient subsequently received conservative management. This paper illustrates the radiological features of flexion teardrop fractures and highlights the importance of prompt diagnosis and management of such cases.

Common accessory ossicles of the foot: imaging features, pitfalls and associated pathology

Accessory ossicles are normal variants that are frequently seen but often overlooked or misdiagnosed. Commonly seen at the foot and ankle, they may be mistaken for fracture fragments or loose bodies, or not be recognised as a cause of the patient's symptoms. This pictorial essay aimed to review commonly encountered accessory ossicles of the foot and ankle by highlighting anatomic landmarks and associated pathologic processes through the use of both basic and advanced imaging modalities, in an effort to increase awareness of these clinical entities.

Inferior vena cava and intra-cardiac invasion of hepatocellular carcinoma: a rare but catastrophic complication

Intra-cardiac extension of hepatocellular carcinoma (HCC) is an uncommon but serious condition related to poor prognosis. We report a 57-year-old male diagnosed with HCC with intra-cardiac extension into the right atrium at presentation. There were no symptoms related to cardiac involvement and intra-cardiac extension was incidentally noted on radiological imaging. He was offered palliative treatment and succumbed to his disease within 50 days of first diagnosis.

Chinese tuina downregulates the elevated levels of tissue plasminogen activator in sciatic nerve injured Sprague-Dawley rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To elucidate the mechanism of Chinese tuina in treating sciatic nerve crush injury, and to detect the levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1), which is thought to play an important role in nerve regeneration.</p><p><b>METHODS</b>Thirty-two adult male Sprague-Dawley rats were subjected to sciatic nerve crush injury and 16 rats (sham-operated group) went through a sham operation. Control group was given no treatment while tuina group received tuina therapy since day 7 post-surgery. Tuina treatment was performed once a day and lasted for 20 days. The sciatic functional index was examined every 5 days during the treatment session. The rats' gastrocnemius muscles were evaluated for changes in mass and immunohistochemistry techniques were performed to detect the levels of tPA and PAI-1.</p><p><b>RESULTS</b>Tuina therapy improved the motor function of sciatic nerve injured rats (P<0.05), however, it did not increase muscle volume (P<0.05). Tuina downregulated the levels of tPA and PAI-1 (P<0.05).</p><p><b>CONCLUSIONS</b>The present study implies that tuina treatment could accelerate rehabilitation of peripheral nerve injury.</p>

Clinics in diagnostic imaging (181). Cervical spine perineural cysts

A 47-year-old woman who underwent resection of known spinal meningioma at the T1 level returned for postoperative magnetic resonance imaging of the cervical spine. Incidentally, thin-walled structures with signal intensities that are similar to those of cerebrospinal fluid were found to be present in the left neural exit canal at the C7-T1 level and bilateral neural exit canals at the C6-7 level. Imaging findings were in keeping with perineural cysts. Cervical spine perineural cysts are likely underreported, as most of them are asymptomatic. The imaging features and differential diagnoses of perineural cysts are discussed in this article.

Protective effects of traditional Tibetan medicine Zuo-Mu-A Decoction () on the blood parameters and myocardium of high altitude polycythemia model rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To explore the protective effects of Tibetan medicine Zuo-Mu-A Decoction (, ZMAD) on the blood parameters and myocardium of high altitude polycythemia (HAPC) model rats.</p><p><b>METHODS</b>Forty male Wistar rats were randomly divided into 4 groups by a random number table, including the normal, model, Rhodiola rosea L. (RRL) and ZMAD groups (10 in each group). Every group was raised in Lhasa to create a HAPC model except the normal group. After modeling, rats in the RRL and the ZMAD groups were administered intragastrically with RRL (20 mL/kg) and ZMAD (7.5 mL/kg) once a day for 2 months, respectively; for the normal and the model groups, 5 mL of distilled water was administered intragastrically instead of decoction. Then routine blood and hematologic rheology parameters were taken, levels of erythropoietin and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were tested, and ultrastructural change in the left ventricular myocardium was observed using transmission electron microscopy.</p><p><b>RESULTS</b>Compared with the model group, ZMAD significantly reduced the red blood cell count, hemoglobin levels, whole blood viscosity at low/middle shear rates, plasma viscosity, erythrocyte electrophoretic time, erythropoietin and 8-OHdG levels, and also increased the erythrocyte deformation index (P<0.05). There was no difference in all results between the RRL and the ZMAD groups. The cardiac muscle fibers were well-protected, mitochondrial matrix swelled mildly and ultrastructure changes were less prominent in the ZMAD group compared with the model group.</p><p><b>CONCLUSION</b>ZMAD has significant protective effects on the blood parameters against HAPC, and also has the beneficial effect in protecting against myocardial injury.</p>

"Three Methods and Three Points" regulates p38 mitogen-activated protein kinase in the dorsal horn of the spinal cord in a rat model of sciatic nerve injury.

Tuina is a traditional Chinese treatment for sensory disturbances caused by peripheral nerve injury and related diseases. Our previous studies showed that tuina regulates relevant regions and indices of the spinal dorsal horn using the Dian, Bo, and Rou method in Yinmen (BL37), Yanglingquan (GB34), and Weizhong (BL40). Treatment prevents muscle atrophy, protects spinal cord neurons, and promotes sciatic nerve repair. The mechanisms of action of tuina for treating peripheral nerve injury remain poorly understood. This study established rat models of sciatic nerve injury using the crushing method. Rats received Chinese tuina in accordance with the principle of "Three Methods and Three Points," once daily for 20 days. Tuina intervention reduced paw withdrawal latency and improved wet weight of the gastrocnemius muscle, as well as promoting morphological recovery of sciatic nerve fibers, Schwann cells, and axons. The protein expression levels of phospho-p38 mitogen-activated protein kinase, tumor necrosis factor-α, and interleukin-1ß also decreased. These findings indicate that "Three Methods and Three Points" promoted morphological recovery and improved behavior of rats with peripheral nerve injury.

Clinics in diagnostic imaging (164). Morel-Lavallée lesion

A 31-year-old male motorcyclist presented with prepatellar swelling of the left knee after a collision with a car. Magnetic resonance imaging of the knee showed no bony or ligamentous injury to the knee. Instead, a well-defined, thin-walled, T2-weighted hyperintense fluid collection with internal septations was identified in a prefascial location overlying the left patella and patellar tendon. The findings were in keeping with those of a Morel-Lavallée lesion, a closed internal degloving injury. Morel-Lavallée lesions are occasionally encountered after a blunt soft-tissue trauma. The presentation and imaging features are discussed.

Clinics in diagnostic imaging (169). Intermuscular lipoma in the thenar eminence of the right hand

A 54-year-old woman presented with a large mass on her right hand that was progressively enlarging over a period of a few years. She had cosmetic concerns about the enlarging mass and experienced interference with routine activity. Physical examination revealed a soft, mobile, non-tender, lobulated mass with well-defined margins. Magnetic resonance imaging showed the soft lump to be a lipomatous mass in the deep palmar space of the hand, which was subsequently surgically resected. The imaging features of deep palmar lipomas of the hand and other common benign lesions at this location are discussed.

Clinics in diagnostic imaging (170)

A 30-year-old woman presented with a six-month history of left posterior heel pain. Physical examination revealed a tender, inflamed and indurated posterior heel with a visible bony prominence of the posterosuperior aspect of the calcaneus. Lateral ankle radiography showed a prominent left posterosuperior calcaneal tuberosity and thickening of the distal Achilles tendon outline. Magnetic resonance imaging demonstrated high-signal inflammatory fluid in the retrocalcaneal bursa, increased signal intensity and thickening of the Achilles tendon, and prominence of the posterior calcaneus tuberosity with reactive marrow oedema. The findings are consistent with Haglund's deformity. The patient underwent hind foot surgery after failing a six-month course of conservative therapy. There was no further recurrence of symptoms after surgery. The clinical and radiological features of Haglund's deformity are described, including a short discussion of other causes of hind foot pain.

Clinics in diagnostic imaging (161). Cervical OPLL with cord compression

A 53-year-old man presented with acute cervical myelopathy following a fall. Cervical radiography and computed tomography showed ossification of the posterior longitudinal ligament (OPLL) from C2 to C6 level, with severe cervical canal stenosis and cord compression. Magnetic resonance imaging further showed increased T2-weighted signal in the spinal cord at the level of greatest central spinal canal stenosis. OPLL is a significant cause of myelopathy in Asian populations and is found in up to 25% of patients presenting with cervical compression myelopathy. The clinical presentation, radiological evaluation and management of OPLL are discussed.