BPR3P0128, a non-nucleoside RNA-dependent RNA polymerase inhibitor, inhibits SARS-CoV-2 variants of concern and exerts synergistic antiviral activity in combination with remdesivir.

Viral RNA-dependent RNA polymerase (RdRp), a highly conserved molecule in RNA viruses, has recently emerged as a promising drug target for broad-acting inhibitors. Through a Vero E6-based anti-cytopathic effect assay, we found that BPR3P0128, which incorporates a quinoline core similar to hydroxychloroquine, outperformed the adenosine analog remdesivir in inhibiting RdRp activity (EC50 = 0.66 µM and 3 µM, respectively). BPR3P0128 demonstrated broad-spectrum activity against various severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern. When introduced after viral adsorption, BPR3P0128 significantly decreased SARS-CoV-2 replication; however, it did not affect the early entry stage, as evidenced by a time-of-drug-addition assay. This suggests that BPR3P0128's primary action takes place during viral replication. We also found that BPR3P0128 effectively reduced the expression of proinflammatory cytokines in human lung epithelial Calu-3 cells infected with SARS-CoV-2. Molecular docking analysis showed that BPR3P0128 targets the RdRp channel, inhibiting substrate entry, which implies it operates differently-but complementary-with remdesivir. Utilizing an optimized cell-based minigenome RdRp reporter assay, we confirmed that BPR3P0128 exhibited potent inhibitory activity. However, an enzyme-based RdRp assay employing purified recombinant nsp12/nsp7/nsp8 failed to corroborate this inhibitory activity. This suggests that BPR3P0128 may inhibit activity by targeting host-related RdRp-associated factors. Moreover, we discovered that a combination of BPR3P0128 and remdesivir had a synergistic effect-a result likely due to both drugs interacting with separate domains of the RdRp. This novel synergy between the two drugs reinforces the potential clinical value of the BPR3P0128-remdesivir combination in combating various SARS-CoV-2 variants of concern.

Modifications of lipid pathways restrict SARS-CoV-2 propagation in human induced pluripotent stem cell-derived 3D airway organoids.

BACKGROUND: Modifications of lipid metabolism were closely associated with the manifestations and prognosis of coronavirus disease of 2019 (COVID-19). Pre-existing metabolic conditions exacerbated the severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection while modulations of aberrant lipid metabolisms alleviated the manifestations. To elucidate the underlying mechanisms, an experimental platform that reproduces human respiratory physiology is required. METHODS: Here we generated induced pluripotent stem cell-derived airway organoids (iPSC-AOs) that resemble the human native airway. Single-cell sequencing (ScRNAseq) and microscopic examination verified the cellular heterogeneity and microstructures of iPSC-AOs, respectively. We subjected iPSC-AOs to SARS-CoV-2 infection and investigated the treatment effect of lipid modifiers statin drugs on viral pathogenesis, gene expression, and the intracellular trafficking of the SARS-CoV-2 entry receptor angiotensin-converting enzyme-2 (ACE-2). RESULTS: In SARS-CoV-2-infected iPSC-AOs, immunofluorescence staining detected the SARS-CoV-2 spike (S) and nucleocapsid (N) proteins and bioinformatics analysis further showed the aberrant enrichment of lipid-associated pathways. In addition, SARS-CoV-2 hijacked the host RNA replication machinery and generated the new isoforms of a high-density lipoprotein constituent apolipoprotein A1 (APOA1) and the virus-scavenging protein deleted in malignant brain tumors 1 (DMBT1). Manipulating lipid homeostasis using cholesterol-lowering drugs (e.g. Statins) relocated the viral entry receptor angiotensin-converting enzyme-2 (ACE-2) and decreased N protein expression, leading to the reduction of SARS-CoV-2 entry and replication. The same lipid modifications suppressed the entry of luciferase-expressing SARS-CoV-2 pseudoviruses containing the S proteins derived from different SARS-CoV-2 variants, i.e. wild-type, alpha, delta, and omicron. CONCLUSIONS: Together, our data demonstrated that modifications of lipid pathways restrict SARS-CoV-2 propagation in the iPSC-AOs, which the inhibition is speculated through the translocation of ACE2 from the cell membrane to the cytosol. Considering the highly frequent mutation and generation of SARS-CoV-2 variants, targeting host metabolisms of cholesterol or other lipids may represent an alternative approach against SARS-CoV-2 infection.

Tumor Necrosis Factor-Alpha Exacerbates Viral Entry in SARS-CoV2-Infected iPSC-Derived Cardiomyocytes.

The coronavirus disease 2019 (COVID-19) pandemic with high infectivity and mortality has caused severe social and economic impacts worldwide. Growing reports of COVID-19 patients with multi-organ damage indicated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) may also disturb the cardiovascular system. Herein, we used human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMs) as the in vitro platform to examine the consequence of SARS-CoV2 infection on iCMs. Differentiated iCMs expressed the primary SARS-CoV2 receptor angiotensin-converting enzyme-II (ACE2) and the transmembrane protease serine type 2 (TMPRSS2) receptor suggesting the susceptibility of iCMs to SARS-CoV2. Following the infection of iCMs with SARS-CoV2, the viral nucleocapsid (N) protein was detected in the host cells, demonstrating the successful infection. Bioinformatics analysis revealed that the SARS-CoV2 infection upregulates several inflammation-related genes, including the proinflammatory cytokine tumor necrosis factor-α (TNF-α). The pretreatment of iCMs with TNF-α for 24 h, significantly increased the expression of ACE2 and TMPRSS2, SASR-CoV2 entry receptors. The TNF-α pretreatment enhanced the entry of GFP-expressing SARS-CoV2 pseudovirus into iCMs, and the neutralization of TNF-α ameliorated the TNF-α-enhanced viral entry. Collectively, SARS-CoV2 elevated TNF-α expression, which in turn enhanced the SARS-CoV2 viral entry. Our findings suggest that, TNF-α may participate in the cytokine storm and aggravate the myocardial damage in COVID-19 patients.

Irreducible metatarsophalangeal joint dislocation of the lesser toes: a case report.

Irreducible metatarsophalangeal joint dislocation of the lesser toes is a rare injury. We present a 37-year-old man who was injured in a motorcycle accident and dislocated the first to third metatarsophalangeal joints and fractured the fourth metatarsal head. The left first metatarsophalangeal joint was reduced successfully through the closed method, but multiple attempts at closed reduction under local anesthesia failed to reduce the dislocated second and third metatarsophalangeal joints. We performed a dorsal incision between the second and third metatarsals, and the metatarsal heads were found to be entrapped under the plantar plate. Dislocation reduction was performed without damage to the plantar plate, and one Kirschner wire was used to fix the fourth metatarsal head fracture. The pin was removed 8 weeks after surgery, and the patient regained normal gait and returned to work and his previous physical activity level without recurrent dislocation.

Anterior approach for posteromedial tibial plateau fractures.

Fractures of the posteromedial tibial plateau are rare and their treatment is not well established. Between January 2004 and December 2008, eight patients with fractures of the posteromedial tibia plateau were identified. All patients were treated with fracture reduction using an anterior approach. After a mean follow-up of 21 months, the average range of knee motion was 0-123 degrees of flexion. Seven patients had been injured in motor-scooter accidents, in which the protective front plate of the scooter had hit the knee while it was in the 90 degrees -flexion position. At the final follow-up, 87.5% (7/8) patients had satisfactory reductions of the articular surface, and all patients had acceptable alignments. There were no neural or vascular injuries following surgery, and no superficial or deep infections. The average Hospital for Special Surgery Knee Score was 89. In conclusion, fracture reduction using the anterior approach is associated with fewer complications than the posterior approach, and good functional recovery can be expected.

Minimally invasive fixation of displaced midclavicular fractures with titanium elastic nails.

OBJECTIVES: Clavicular fractures account for 2.6% of all fractures, and more than 80% involve the middle third of the clavicle. Plate fixation has been the most common method of fixation reported but has been associated with complications such as infection, wound breakdown, nonunion, implant failures, poor cosmetic outcome, and local skin numbness. We report on a series of cases receiving minimally invasive insertion of titanium elastic nails (TEN) to fix the displaced midclavicular fractures. DESIGN: Prospective, clinical study. SETTING: Regional referral center. PATIENTS/PARTICIPANTS: From November 2006 to October 2007, we operated on 23 patients (16 men) with displaced (no cortical contact between the proximal and distal fragments radiographically and/or greater than 2 cm of shortening) midclavicular fractures fixed with TEN. The mean age of the patients was 41.57 years. INTERVENTION: All patients with displaced midclavicular fractures were treated with TEN. The nails were inserted from the medial entry point on the sternal end and passed through the fracture site under fluoroscopy monitoring. MAIN OUTCOME MEASUREMENTS: Complications, clavicular shortening after TEN fixation, Constant shoulder score, and Disability of the Arm, Shoulder, and Hand score for functional outcome measurement. RESULTS: Closed reduction was successful in 16 patients, and seven patients needed open reduction. There was no nonunion, infection, nail breakage, or refracture after nail removal in our series. The mean operative wound length was 2.2 cm, and mean clavicular length shortening was 0.32 cm. Iatrogenic perforation of the lateral cortex occurred in two patients, and nail misplacement occurred in one patient requiring revision. All patients followed up greater than 12 months. The mean Disability of the Arm, Shoulder, and Hand score was 6 (range, 0-35; standard deviation, 10.47) and mean Constant score was 96 (range, 78-100; standard deviation, 6.34). CONCLUSIONS: Minimally invasive fixation with TEN is a safe method and can be performed with minor complications. This method of fixation of displaced midclaviclular fractures should result in a good cosmetic appearance and satisfactory stabilization of displaced midclavicular fractures without comminution.

Isolated posterior cruciate ligament injuries associated with closed tibial shaft fractures: a report of two cases.

INTRODUCTION: Knee ligament injuries associated with tibia shaft fractures are usually neglected and treatment is delayed. To our knowledge, no case presentation discusses the clinical result of closed tibial shaft fracture with concomitant ipsilateral isolated PCL injury. In this literature, we report the clinical result of two cases that sustained closed tibial shaft fracture with concomitant PCL injury and discuss the treatment options. MATERIALS AND METHODS: We report the clinical result of two cases that sustained closed tibial shaft fracture with concomitant posterior cruciate ligament (PCL) injury. Case 1 received open reduction with plate fixation for the tibial shaft fracture, and he also received arthroscopic reconstruction of PCL with bone-patellar tendon-bone graft due to neglecting PCL injury 5 months later after fracture fixation. Case 2 sustained left tibial-fibular shaft fracture with isolated PCL injury confirmed by magnetic resonance image on the first day of injury. She received tibia fixation with intramedullary nail and conservative treatment with bracing and rehabilitation for PCL injury. RESULTS: In case 1, the male patient only focused on fracture healing without any knee rehabilitation. His knee flexed deeply for protected weight bearing in the injured leg which may have exacerbated the posterior instability and reduced the possibility of PCL healing. The end result of knee function was poor even though PCL reconstruction was done later. In case 2, the female patient with diagnosed posterior cruciate ligament injury on the day of injury, her knee was immobilized in brace with full extension, which improved PCL healing. In addition, she received rehabilitation of quadriceps strengthening, and hamstring muscle contraction was avoided in her daily activity. After rehabilitation, the female patient did not complain of severe subjective instability even with an obvious posterior translation on posterior drawer test. CONCLUSIONS: We need to perform a careful physical examination of ipsilateral knee in cases of leg fractures, and MRI of knee before surgery if any doubt exists. However, a further research is needed to conclude on the best operation and rehabilitation program in patients with combined tibial shaft fracture and PCL injury.

Infection after surgical reconstruction of a clavicle fracture using a reconstruction plate: a report of seven cases.

Mid-shaft clavicle fractures have traditionally been treated conservatively, although this has been associated with non-union and unsatisfactory shoulder function. The preferred approach is plate fixation, with a reconstruction plate for open reduction and internal fixation. Infection is a potential complication after such surgery, with rates of 0.4-7.8% reported in the literature. In our cases, an infection rate of 4.9% (7 of 142 patients) was noted; five of the seven patients suffered from acute postoperative infection within 1 month of surgery. The average time to presentation with an infection was 28 (23-32) days, with signs and symptoms of wound dehiscence in one patient and sinus discharge in four patients. Two patients suffered from subacute infections, with durations of 72 and 103 days, presenting with local heat and radiographic findings of screw loosening. Six of the cases healed with primary bony union after intensive debridement and early removal of the implants.

Percutaneous antegrade screwing for anterior column fracture of acetabulum with fluoroscopic-based computerized navigation.

INTRODUCTION: Open reduction and internal fixation has been the gold standard for displaced fracture involving weightbearing dome and fractures with intra-articular fragments. However, extensile exposure can lead to complications. Fracture with minimal displacement can be fixed by a minimally invasive method. Percutaneous screwing for an anterior column fracture of acetabulum under conventional 2D fluoroscopy is a demanding technique. With fluoroscopic-based computerized navigation, we can determine the position of a screw real time intra-operatively with less exposure to radiation. We proposed that a fluoroscopy-based computerized navigational system would simplify operation procedures. The purpose of this study is to test the application of the fluoroscopy-based computerized navigational system for anterior column fracture of acetabulum. MATERIALS AND METHODS: A prospective cohort study was conducted. Three patients with mildly displaced or non-displaced anterior column fracture of acetabulum were treated with a retrograde lag screw under a fluoroscopy-based computer navigation system. There were two males and one female with a mean age of 39 years and all patients were followed up for more than 1 year. Patients were allowed to perform joint movement exercises and to walk with partial weightbearing on the first day post-operatively. RESULTS: The mean operation time was 40 min (range 30-45 min) from the use of fluoroscopy to wound closure and the mean total fluoroscopy time was 38 s (range 35-45 s). Total blood loss was less than 10 ml. The patients were pain free 1 week after the operation and had good functional recovery thereafter. No complication was noted postoperatively. CONCLUSION: Though the indication for this procedure is limited, we think that there should be potential to apply the screw with less radiation by fluoroscopic-based computerized navigation. Once anatomic reduction can be achieved by the close method in the anterior column fracture of the acetabulum, percutaneous screw fixation under fluoroscopic-based computerized navigation could be a reliable method; however; validating the position of the guide pin and screw by fluoroscopy is suggested.

Snapping knee symptoms caused by an intra-articular ganglion cyst.

Snapping knee syndrome describes the sudden movement of a soft-tissue structure across a bony prominence around the knee with a popping sound at some specific activity. Symptomatic snapping knee syndrome may result from an intra-articular tumor, but this situation is rare. To the best of our knowledge, an intra-articular ganglion cyst leading to snapping knee has not been reported previously. A 20 year old female with painful snapping knee was successfully treated by open en-bloc excision of the ganglion cyst sized 4.5 x 1.5 x 1 cm on the ligamentum mucosum. Snapping and pain were completely relieved after surgery. Although the snapping knee is not common over the antero-lateral portion of the knee joint, a ganglion cyst from the ligamentum mucosum is a possible cause.

Surgical treatment of type II floating knee: comparisons of the results of type IIA and type IIB floating knee.

The prognosis of type II floating knee injuries was not as good as that of type I. Our purpose is to clarify the factors affecting the outcome of type II floating knee injuries. Thirty-five patients (36 limbs) with type II floating knee injury were studied with a mean follow-up of 52 months (26-96). Blake and McBryde had classified these injuries into type I for pure diaphyseal (true type) fracture and type II if the intra-articular involvements are one or more including hip, knee and ankle joints (variant type). According to this classification, we divided these patients into two groups depending on whether their knees were involved or not. Those cases with intra-articular knee involvement were classified as type IIA, while those without intra-articular knee involvement were classified as type IIB. Of the 36 cases, 21 were classified as type IIA and 15 were type IIB. The functional outcomes of these injuries were evaluated by using the criteria of Karlström and Olerud and analyzed with multivariate analysis. After multivariate analysis with logistic regression, we show the following results: first, the poor functional outcome of type II floating knee is contributed by type IIA. Second, the type IIA group has severer femoral open fracture grading (P = 0.027) and poorer functional outcome (P = 0.009) than type IIB. Third, the significant contributing factors to final outcome are the group (P = 0.013) and the fixation time after injury in femur (P = 0.015). Intra-articular knee involvement is the most important factor contributing to poor outcome of type II floating knee. The treatment of floating knee injuries with intra-articular knee involvement is still difficult. Further efforts to search better methods of treatment are required for these complex injuries in the future.

Anterior subtalar dislocation: a case report.

Anterior subtalar dislocations are extremely rare. To our knowledge, six cases have been reported in detail in the literature, but for only two of these was an anteroposterior view radiograph used to confirm the diagnosis. We report a case of anterior subtalar dislocation in which the posterior tibialis tendon was incarcerated in the talonavicular joint and that required an open reduction. We discuss the diagnosis, mechanism, and treatment.