Lung Transplantation in a Patient with COVID-19-Associated Acute Respiratory Failure

Coronavirus disease 2019 (COVID-19) is currently a significant cause of acute respiratory failure worldwide, leading to irreversible fibrotic lung disease. In patients with persistent respiratory failure after acute COVID-19 infection, lung transplant is an emerging option. Here, we have presented a case where the patient required venovenous extracorporeal membrane oxygenation (VV-ECMO) support for 33 days until a bilateral lung transplant was performed on day 71 after the initial COVID-19 infection. The early outcomes have been favorable. Currently, no guidelines exist for an acceptable time period after initial COVID-19 infection, duration of negative COVID polymerase chain reaction (PCR) testing, or negative Vero cell culture in the setting of persistent positive COVID PCR testing before listing for a lung transplant. Due to a lack of standardized guidelines, this patient was not listed for a lung transplant until the COVID-19 PCRs came negative on days 47 and 49 after the infection

Pregabalin-Induced Myopathy in a Double Lung Transplant Recipient

Pregabalin is a gamma-aminobutyric acid (GABA) derivative that was commercially approved by the Food and Drug Administration (FDA) in 2004. It is commonly used in the treatment of diabetic neuropathy, peripheral neuropathy, and spinal cord injury. We present the case of a 36-year-old Caucasian male double lung transplant recipient who presented with an 18-month history of fatigue and muscle weakness. He had elevated creatinine kinase level and his muscle biopsy showed evidence of drug-induced myopathy that improved after the cessation of pregabalin. We present a case of drug-induced myopathy as a rare complication of pregabalin therapy in a double lung transplant recipient

Non-Invasive Detection of SARS-CoV-2 Antigen in Saliva versus Nasopharyngeal Swabs Using Nanobodies Conjugated Gold Nanoparticles

The development of sensitive, non-invasive tests for the detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigens is imperative, and it is still challenging to manage the extent of infection throughout the population. Here, we designed and optimized a sandwich enzyme-linked immunosorbent assay (ELISA) protocol for SARS-CoV-2 S1 antigen detection in saliva. Both saliva samples and nasopharyngeal swabs were collected from 220 real-time quantitative polymerase chain reaction (RT-qPCR)-confirmed positive and negative cases. S1 protein receptor-binding domain (RBD) nanobodies were efficiently conjugated with 40 nm gold nanoparticles (AuNPs) and employed as antigen detection probes in the developed system, while recombinant S1 monoclonal antibodies (S1mAbs) were employed as antigen capture probes. After checkerboard assays and system optimization, the clinical samples were tested. In saliva, the developed ELISA system showed the highest sensitivity (93.3) for samples with cycle threshold (Ct) values ≤ 30; interestingly, high sensitivity (87.5 and 86%) was also achieved for samples with Ct values ≤ 35 and ≤40, respectively, compared with 90, 80 and 88% sensitivity rates for nasopharyngeal swabs with the same categorized Ct values. However, the specificity was 100%, and no cross-reactions were detected with Middle East respiratory syndrome coronavirus (MERS-CoV) or SARS-CoV antigens. These results reveal that our protocol could be established as an efficient and sensitive, non-invasive diagnostic tool for the early detection of SARS-CoV-2 infection using easily collectable saliva samples

Purification and biochemical characterization of taxadiene synthase from bacillus koreensis and stenotrophomonas maltophilia

Taxadiene synthase (TDS) is the rate-limiting enzyme of Taxol biosynthesis that cyclizes the geranylgeranyl pyrophosphate into taxadiene. Attenuating Taxol productivity by fungi is the main challenge impeding its industrial application; it is possible that silencing the expression of TDS is the most noticeable genomic feature associated with Taxol-biosynthetic abolishing in fungi. As such, the characterization of TDS with unique biochemical properties and autonomous expression that is independent of transcriptional factors from the host is the main challenge. Thus, the objective of this study was to kinetically characterize TDS from endophytic bacteria isolated from different plants harboring Taxol-producing endophytic fungi. Among the recovered 23 isolates, Bacillus koreensis and Stenotrophomonas maltophilia achieved the highest TDS activity. Upon using the Plackett–Burman design, the TDS productivity achieved by B. koreensis (18.1 µmol/mg/min) and S. maltophilia (14.6 µmol/mg/min) increased by ~2.2-fold over the control. The enzyme was purified by gel-filtration and ion-exchange chromatography with ~15 overall folds and with molecular subunit structure 65 and 80 kDa from B. koreensis and S. maltophilia, respectively. The chemical identity of taxadiene was authenticated from the GC-MS analyses, which provided the same mass fragmentation pattern of authentic taxadiene. The tds gene was screened by PCR with nested primers of the conservative active site domains, and the amplicons were sequenced, displaying a higher similarity with tds from T. baccata and T. brevifolia. The highest TDS activity by both bacterial isolates was recorded at 37–40 °C. The Apo-TDSs retained ~50% of its initial holoenzyme activities, ensuring their metalloproteinic identity. The activity of purified TDS was completely restored upon the addition of Mg2+, confirming the identity of Mg2+ as a cofactor. The TDS activity was dramatically reduced upon the addition of DTNB and MBTH, ensuring the implementation of cysteine-reactive thiols and ammonia groups on their active site domains. This is the first report exploring the autonomous robust expression TDS from B. koreensis and S. maltophilia with a higher affinity to cyclize GGPP into taxadiene, which could be a novel platform for taxadiene production as intermediary metabolites of Taxol biosynthesis

Pleural mesothelial cell transformation into myofibroblasts and haptotactic migration in response to TGF-β1 in vitro

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology characterized by the development of subpleural foci of myofibroblasts that contribute to the exuberant fibrosis noted in the pulmonary parenchyma. Pleural mesothelial cells (PMC) are metabolically dynamic cells that cover the lung and chest wall as a monolayer and are in intimate proximity to the underlying lung parenchyma. The precise role of PMC in the pathogenesis of pulmonary parenchymal fibrosis remains to be identified. Transforming growth factor (TGF)-β1, a cytokine known for its capacity to induce proliferative and transformative changes in lung cells, is found in significantly higher quantities in the lungs of patients with IPF. High levels of TGF-β1 in the subpleural milieu may play a key role in the transition of normal PMC to myofibroblasts. Here we demonstrate that PMC activated by TGF-β1 undergo epithelial-mesenchymal transition (EMT) and respond with haptotactic migration to a gradient of TGF-β1 and that the transition of PMC to myofibroblasts is dependent on smad-2 signaling. The EMT of PMC was marked by upregulation of α-smooth muscle actin (α-SMA), fibroblast specific protein-1 (FSP-1), and collagen type I expression. Cytokeratin-8 and E-cadherin expression decreased whereas vimentin remained unchanged over time in transforming PMC. Knockdown of smad-2 gene by silencing small interfering RNA significantly suppressed the transition of PMC to myofibroblasts and significantly inhibited the PMC haptotaxis. We conclude that PMC undergo EMT when exposed to TGF-β1, involving smad-2 signaling, and PMC may be a possible source of myofibroblasts in IPF

Two Decades of Lung Retransplantation: A Single-Center Experience

Lung retransplantation (ReTx) comprises an increasing share of lung transplants and recently has shown improved outcomes. The aim of this study was to identify risk factors affecting overall survival after pulmonary ReTx. The United Network for Organ Sharing database was used to identify patients undergoing lung transplantation at our institution from 1995 to 2014. Of the total 542 lung transplants performed, 87 (16.1%) were ReTxs. The primary outcome was overall survival. Multivariate Cox regression models were used to assess the effect of recipient and donor characteristics on survival. Of the patients who underwent ReTx, median survival was 2 years. Predictors of worse survival include recipient age between 50 and 60 years (relative risk, 4.3; p = 0.02) or older than 60 years (relative risk, 10.2; p < 0.001), and time to ReTx of less than 2 years (relative risk, 3.8; p = 0.01). ReTx for bronchiolitis obliterans syndrome had longer median survival than for restrictive chronic lung allograft dysfunction (2.7 years vs 0.9 years; p = 0.055). Overall survival of ReTx patients after initiation of the lung allocation score was not significantly different (p = 0.21). Lung ReTx outcomes are significantly worse than for primary transplantation but may be appropriate in well-selected patients with certain diagnoses. Lung ReTx in patients older than 50 years or within 2 years of primary lung transplantation was associated with decreased survival. Further work is warranted to identify patients who benefit most from ReTx

Studying Autism Spectrum Disorder with Structural and Diffusion Magnetic Resonance Imaging: A Survey

Magnetic resonance imaging (MRI) modalities have emerged as powerful means that facilitatenon-invasive clinical diagnostics of various diseases and abnormalities since their inception in the1980s. Multiple MRI modalities, such as different types of the sMRI and DTI, have been employedto investigate facets of ASD in order to better understand this complex syndrome. This paperreviews recent applications of structural magnetic resonance imaging (sMRI) and diffusion tensorimaging (DTI), to study autism spectrum disorder (ASD). Main reported findings are sometimescontradictory due to different age ranges, hardware protocols, population types, numbers of participants,and image analysis parameters. The primary anatomical structures, such as amygdalae,cerebrum, and cerebellum, associated with clinical-pathological correlates of ASD are highlightedthrough successive life stages, from infancy to adulthood. This survey demonstrates the absenceof consistent pathology in the brains of autistic children and lack of research investigations in patientsunder two years of age in the literature. The known publications also emphasize advancesin data acquisition and analysis, as well as significance of multimodal approaches that combineresting-state, task-evoked, and sMRI measures. Initial results obtained with the sMRI and DTIshow good promise towards the early and non-invasive ASD diagnostics