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.

Development of an EBOV MiniG plus system as an advanced tool for anti-Ebola virus drug screening.

The incidence of zoonotic diseases, such as coronavirus disease 2019 and Ebola virus disease, is increasing worldwide. However, drug and vaccine development for zoonotic diseases has been hampered because the experiments involving live viruses are limited to high-containment laboratories. The Ebola virus minigenome system enables researchers to study the Ebola virus under BSL-2 conditions. Here, we found that the addition of the nucleocapsid protein of human coronaviruses, such as severe acute respiratory syndrome coronavirus 2, can increase the ratio of green fluorescent protein-positive cells by 1.5-2 folds in the Ebola virus minigenome system. Further analysis showed that the nucleocapsid protein acts as an activator of the Ebola virus minigenome system. Here, we developed an EBOV MiniG Plus system based on the Ebola virus minigenome system by adding the SARS-CoV-2 nucleocapsid protein. By evaluating the antiviral effect of remdesivir and rupintrivir, we demonstrated that compared to that of the traditional Ebola virus minigenome system, significant concentration-dependent activity was observed in the EBOV MiniG Plus system. Taken together, these results demonstrate the utility of adding nucleocapsid protein to the Ebola virus minigenome system to create a powerful platform for screening antiviral drugs against the Ebola virus.

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.

Immunoglobulin Y Specific for SARS-CoV-2 Spike Protein Subunits Effectively Neutralizes SARS-CoV-2 Infectivity and Ameliorates Disease Manifestations In Vivo.

(Background) The coronavirus disease 2019 (COVID-19) that is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) carries high infectivity and mortality. Efficient intervention strategies are urgently needed. Avian immunoglobulin Y (IgY) showed efficacy against viral infection whereas the in vivo efficacy remains unclear. (Methods) We immunized laying hens with S1, S1 receptor-binding domain (S1-RBD), or S2 subunits of the SARS-CoV-2 spike (S) protein. After immunization, IgYs were collected and extracted from the egg yolks. The neutralization potential of IgYs was examined by the plaque reduction neutralization test (PRNT). The bioutility of IgYs was examined in Syrian hamsters in vivo. (Results) IgYs exhibited typical banding patterns in SDS-PAGE and Western blot and were immunoreactive against S1, S1-RBD, and S2 subunits. The plaque reduction neutralization test (PRNT) showed that all purified IgYs potently neutralized different SARS-CoV-2 strains in vitro. In Syrian hamsters, the combination of IgYs for S1-RBD and S2 subunits administered before or after SARS-CoV-2 infection effectively restored body weight loss and reduced intrapulmonary lesions and the amount of immunoreactive N protein-positive cells, which were caused by SARS-CoV-2 infection. (Conclusions) Collectively, IgYs specific for S protein subunits effectively neutralized SARS-CoV-2 in vitro and in vivo and may serve as prophylactic or therapeutic antibodies in the prevention or treatment of COVID-19.

The Role of Autophagy in Osteoarthritic Cartilage.

Osteoarthritis (OA) is one of the most common diseases leading to physical disability, with age being the main risk factor, and degeneration of articular cartilage is the main focus for the pathogenesis of OA. Autophagy is a crucial intracellular homeostasis system recycling flawed macromolecules and cellular organelles to sustain the metabolism of cells. Growing evidences have revealed that autophagy is chondroprotective by regulating apoptosis and repairing the function of damaged chondrocytes. Then, OA is related to autophagy depending on different stages and models. In this review, we discuss the character of autophagy in OA and the process of the autophagy pathway, which can be modulated by some drugs, key molecules and non-coding RNAs (microRNAs, long non-coding RNAs and circular RNAs). More in-depth investigations of autophagy are needed to find therapeutic targets or diagnostic biomarkers through in vitro and in vivo situations, making autophagy a more effective way for OA treatment in the future. The aim of this review is to introduce the concept of autophagy and make readers realize its impact on OA. The database we searched in is PubMed and we used the keywords listed below to find appropriate article resources.

The Role of Mitochondrial Metabolism, AMPK-SIRT Mediated Pathway, LncRNA and MicroRNA in Osteoarthritis.

Osteoarthritis (OA) is the most common joint disease characterized by degeneration of articular cartilage and causes severe joint pain, physical disability, and impaired quality of life. Recently, it was found that mitochondria not only act as a powerhouse of cells that provide energy for cellular metabolism, but are also involved in crucial pathways responsible for maintaining chondrocyte physiology. Therefore, a growing amount of evidence emphasizes that impairment of mitochondrial function is associated with OA pathogenesis; however, the exact mechanism is not well known. Moreover, the AMP-activated protein kinase (AMPK)-Sirtuin (SIRT) signaling pathway, long non-coding RNA (lncRNA), and microRNA (miRNA) are important for regulating the physiological and pathological processes of chondrocytes, indicating that these may be targets for OA treatment. In this review, we first focus on the importance of mitochondria metabolic dysregulation related to OA. Then, we show recent evidence on the AMPK-SIRT mediated pathway associated with OA pathogenesis and potential treatment options. Finally, we discuss current research into the effects of lncRNA and miRNA on OA progression or inhibition.

Dynamic Changes of the Blood Chemistry in Syrian Hamsters Post-Acute COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that causes coronavirus disease 2019 (COVID-19). However, the long-term health consequences of COVID-19 are not fully understood. We aimed to determine the long-term lung pathology and blood chemistry changes in Syrian hamsters infected with SARS-CoV-2. Syrian hamsters (Mesocricetus auratus) were inoculated with 105 PFU of SARS-CoV-2, and changes post-infection (pi) were observed for 20 days. On days 5 and 20 pi, the lungs were harvested and processed for pathology and viral load count. Multiple blood samples were collected every 3 to 5 days to observe dynamic changes in blood chemistry. Infected hamsters showed consistent weight loss until day 7 pi At day 5 pi, histopathology of the lungs showed moderate to severe inflammation and the virus could be detected. These results indicate that SARS-CoV-2 has an acute onset and recovery course in the hamster infection model. During the acute onset, blood triglyceride levels increased significantly at day 3 pi During the recovery course, uric acid and low-density lipoprotein levels increased significantly, but the total protein and albumin levels decreased. Together, our study suggests that SARS-CoV-2 infection in hamsters not only causes lung damage but also causes long-term changes in blood biochemistry during the recovery process. IMPORTANCE COVID-19 is now considered a multiorgan disease with a wide range of manifestations. There are increasing reports of persistent and long-term effects after acute COVID-19, but the long-term health consequences of COVID-19 are not fully understood. This study reported for the first time the use of blood samples collected continuously in a SARS-CoV-2-infected hamster model, which provides more information about the dynamic changes in blood biochemistry during the acute and recovery phases of SARS-CoV-2 infection. Our study suggests that SARS-CoV-2 infection in hamsters not only causes lung damage but also causes long-term changes in blood biochemistry during the recovery process. The study may be used by several researchers and clinicians, especially those who are studying potential treatments for patients with post-acute COVID-19 syndrome.

A siRNA targets and inhibits a broad range of SARS-CoV-2 infections including Delta variant.

The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants has altered the trajectory of the COVID-19 pandemic and raised some uncertainty on the long-term efficiency of vaccine strategy. The development of new therapeutics against a wide range of SARS-CoV-2 variants is imperative. We, here, have designed an inhalable siRNA, C6G25S, which covers 99.8% of current SARS-CoV-2 variants and is capable of inhibiting dominant strains, including Alpha, Delta, Gamma, and Epsilon, at picomolar ranges of IC50 in vitro. Moreover, C6G25S could completely inhibit the production of infectious virions in lungs by prophylactic treatment, and decrease 96.2% of virions by cotreatment in K18-hACE2-transgenic mice, accompanied by a significant prevention of virus-associated extensive pulmonary alveolar damage, vascular thrombi, and immune cell infiltrations. Our data suggest that C6G25S provides an alternative and effective approach to combating the COVID-19 pandemic.

Methotrexate inhibition of SARS-CoV-2 entry, infection and inflammation revealed by bioinformatics approach and a hamster model.

Background: Drug repurposing is a fast and effective way to develop drugs for an emerging disease such as COVID-19. The main challenges of effective drug repurposing are the discoveries of the right therapeutic targets and the right drugs for combating the disease. Methods: Here, we present a systematic repurposing approach, combining Homopharma and hierarchal systems biology networks (HiSBiN), to predict 327 therapeutic targets and 21,233 drug-target interactions of 1,592 FDA drugs for COVID-19. Among these multi-target drugs, eight candidates (along with pimozide and valsartan) were tested and methotrexate was identified to affect 14 therapeutic targets suppressing SARS-CoV-2 entry, viral replication, and COVID-19 pathologies. Through the use of in vitro (EC50 = 0.4 µM) and in vivo models, we show that methotrexate is able to inhibit COVID-19 via multiple mechanisms. Results: Our in vitro studies illustrate that methotrexate can suppress SARS-CoV-2 entry and replication by targeting furin and DHFR of the host, respectively. Additionally, methotrexate inhibits all four SARS-CoV-2 variants of concern. In a Syrian hamster model for COVID-19, methotrexate reduced virus replication, inflammation in the infected lungs. By analysis of transcriptomic analysis of collected samples from hamster lung, we uncovered that neutrophil infiltration and the pathways of innate immune response, adaptive immune response and thrombosis are modulated in the treated animals. Conclusions: We demonstrate that this systematic repurposing approach is potentially useful to identify pharmaceutical targets, multi-target drugs and regulated pathways for a complex disease. Our findings indicate that methotrexate is established as a promising drug against SARS-CoV-2 variants and can be used to treat lung damage and inflammation in COVID-19, warranting future evaluation in clinical trials.

Ugonin J Acts as a SARS-CoV-2 3C-like Protease Inhibitor and Exhibits Anti-inflammatory Properties.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes severe "flu-like" symptoms that can progress to acute respiratory distress syndrome (ARDS), pneumonia, renal failure, and death. From the therapeutic perspective, 3-chymotrypsin-like protein (3CLpro) is a plausible target for direct-acting antiviral agents because of its indispensable role in viral replication. The flavonoid ugonin J (UJ) has been reported to have antioxidative and anti-inflammatory activities. However, the potential of UJ as an antiviral agent remains unexplored. In this study, we investigated the therapeutic activity of UJ against SARS-CoV-2 infection. Importantly, UJ has a distinct inhibitory activity against SARS-CoV-2 3CLpro, compared to luteolin, kaempferol, and isokaempferide. Specifically, UJ blocks the active site of SARS-CoV-2 3CLpro by forming hydrogen bonding and van der Waals interactions with H163, M165 and E166, G143 and C145, Q189, and P168 in subsites S1, S1', S2, and S4, respectively. In addition, UJ forms strong, stable interactions with core pharmacophore anchors of SARS-CoV-2 3CLpro in a computational model. UJ shows consistent anti-inflammatory activity in inflamed human alveolar basal epithelial A549 cells. Furthermore, UJ has a 50% cytotoxic concentration (CC50) and a 50% effective concentration (EC50) values of about 783 and 2.38 µM, respectively, with a selectivity index (SI) value of 329, in SARS-CoV-2-infected Vero E6 cells. Taken together, UJ is a direct-acting antiviral that obstructs the activity of a fundamental protease of SARS-CoV-2, offering the therapeutic potential for 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.

Perilla (Perilla frutescens) leaf extract inhibits SARS-CoV-2 via direct virus inactivation.

BACKGROUND: While severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection presents with mild or no symptoms in most cases, a significant number of patients become critically ill. Remdesivir has been approved for the treatment of coronavirus disease 2019 (COVID-19) in several countries, but its use as monotherapy has not substantially lowered mortality rates. Because agents from traditional Chinese medicine (TCM) have been successfully utilized to treat pandemic and endemic diseases, we designed the current study to identify novel anti-SARS-CoV-2 agents from TCM. METHODS: We initially used an antivirus-induced cell death assay to screen a panel of herbal extracts. The inhibition of the viral infection step was investigated through a time-of-drug-addition assay, whereas a plaque reduction assay was carried out to validate the antiviral activity. Direct interaction of the candidate TCM compound with viral particles was assessed using a viral inactivation assay. Finally, the potential synergistic efficacy of remdesivir and the TCM compound was examined with a combination assay. RESULTS: The herbal medicine Perilla leaf extract (PLE, approval number 022427 issued by the Ministry of Health and Welfare, Taiwan) had EC50 of 0.12 ± 0.06 mg/mL against SARS-CoV-2 in Vero E6 cells - with a selectivity index of 40.65. Non-cytotoxic PLE concentrations were capable of blocking viral RNA and protein synthesis. In addition, they significantly decreased virus-induced cytokine release and viral protein/RNA levels in the human lung epithelial cell line Calu-3. PLE inhibited viral replication by inactivating the virion and showed additive-to-synergistic efficacy against SARS-CoV-2 when used in combination with remdesivir. CONCLUSION: Our results demonstrate for the first time that PLE is capable of inhibiting SARS-CoV-2 replication by inactivating the virion. Our data may prompt additional investigation on the clinical usefulness of PLE for preventing or treating COVID-19.

Zinc finger protein ZFP36L1 inhibits influenza A virus through translational repression by targeting HA, M and NS RNA transcripts.

ZFP36L1, a CCCH-type zinc finger protein, is an RNA-binding protein that participates in controlling cellular mRNA abundance and turnover by posttranscriptional regulation. Here, we demonstrated that ZFP36L1 has an important role in host defense against influenza A virus (IAV) infection. Overexpression of ZFP36L1 reduced IAV replication via translational repression of HA, M and NS RNA segment transcripts. IAV infection upregulated cellular ZFP36L1 expression, and endogenous ZFP36L1 knockdown significantly enhanced IAV replication. ZFP36L1 directly binds to IAV NS1 mRNA in the cytoplasm and blocks the expression and function of NS1 protein. Mutation of CCCH-type zinc finger domains of ZFP36L1 lost its antiviral potential and NS1 mRNA binding. Thus, ZFP36L1 can act as a host innate defense by targeting HA, M and NS mRNA transcripts to suppress viral protein translation.

Titanium Elastic Nail versus plate fixation of displaced midshaft clavicle fractures: A retrospective comparison study.

This study has two purposes: (1) to compare the clinical results between the Titanium Elastic Nail (TEN) and plate fixation of the displaced midshaft clavicle fracture; and (2) to demonstrate the relationship between length shortening and functional outcome after TEN fixation, especially in the comminuted fracture pattern. A retrospective, case-controlled study was conducted and 55 patients were included in our study: 25 in the TEN fixation group (TEN group) and 30 in the plate fixation group (plate group). All patients were classified into four subgroups: simple fracture in the TEN group (ST; n = 13), simple fracture in the plate group (SP; n = 15), comminuted fracture in the TEN group (CT; n = 12), and comminuted fracture in the plate group (CP; n = 15). Wound size was significantly smaller in the TEN group (p < 0.001). The injured clavicular length after fracture healing was significantly shorter in the TEN group (p = 0.036). There was no significant difference in the mean Constant and DASH scores. Injured clavicle shortening was significantly larger in the CT subgroup (p = 0.018). However, there was no statistically significant difference in Constant score and DASH score while comparing the CT subgroup to other subgroups. Although TEN fixation may lead to a higher degree of length shortening after bony union especially in cases of comminuted fracture pattern, no statistically significant difference was observed in objective functional results as compared to other subgroups. Therefore, TEN can be used to fix a displaced midshaft clavicle fracture even in cases of comminuted fracture pattern, which overall is an effective and less surgically invasive procedure.

Complications and technical pitfalls of titanium elastic nail fixation for midclavicular fractures.

Intramedullary titanium elastic nails have been reported to fix displaced midclavicular fractures with excellent functional outcomes and minor complications. This study reports and analyzes the complications and technical pitfalls associated with titanium elastic nail fixation of displaced midclavicular fractures and describes how to prevent these problems. The authors operated on 27 patients (17 men, 10 women; mean age, 45.8 years; range, 16.5-66.9 years) with marked displaced midclavicular fractures using intramedullary titanium elastic nail fixation. The mean Constant score and Disability of the Arm, Shoulder, and Hand score were 93.58 (range, 66.5-100) and 6.22 (range, 0-35), respectively. The mean length difference compared with the contralateral clavicle was a shortening of 0.3 cm (range, -1.5 to 1 cm). Eight patients (30%) had different levels of difficulty at the medial entry point. Clavicular length shortening of more than 1 cm occurred in 5 patients (19%), and all of these patients experienced medial nail tip prominence/protrusion. One patient had 1-cm lengthening of the injured clavicle caused by distraction of the fracture site during titanium elastic nail insertion. Iatrogenic perforation of the posterolateral cortex occurred in 3 patients. Initial misplaced nail insertion occurred in 1 woman who underwent revision with the mini-open method. In 2 patients it was impossible to remove the full nail under general anesthesia. In conclusion, high patient satisfaction and functional outcomes were achieved after titanium elastic nail fixation of displaced midclavicular fractures. However, some complications and technical pitfalls must be considered before titanium elastic nails are used to fix displaced midclavicular fractures.

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.

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.

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.

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.

Effects of a bioscaffold on collagen fibrillogenesis in healing medial collateral ligament in rabbits.

Bioscaffolds have been successfully used to improve the healing of ligaments and tendons. In a rabbit model, the application of porcine small intestine submucosa (SIS) to the healing medial collateral ligament (MCL) resulted in improved mechanical properties with the formation of larger collagen fibrils. Thus, the objective of the study was to find out whether the SIS bioscaffold could improve the gene expressions of fibrillogenesis-related molecules, specifically, collagen types I, III, V, and small leucine-rich proteoglycans including decorin, biglycan, lumican, and fibromodulin, as well as collagen fibril morphology and organization, in the healing rabbit MCL at an early time point (6 weeks postinjury). Twenty skeletally mature rabbits were equally divided into two groups. In the SIS-treated group, a 6-mm gap was surgically created and a layer of SIS was sutured to cover the gap, whereas the gap was left open in the nontreated group. At 6 weeks postinjury, Masson's trichrome staining showed that the SIS-treated group had more regularly aligned collagen fibers and cells. Transmission electron microscopy revealed that the SIS-treated group had larger collagen fibrils with a diameter distribution from 24 to 120 nm, whereas the nontreated group had only small collagen fibrils (ranging from 26 to 87 nm, p < 0.05). Finally, the quantitative real-time PCR showed that the mRNAs of collagen type V, decorin, biglycan, and lumican in the SIS-treated group were 41, 58, 51, and 43% lower than those in the nontreated group, respectively (p < 0.05). Such significant reduction in the gene expressions are closely related to the improved morphological characteristics, which are known to be coupled with better mechanical properties, as previously reported in longer term studies.