ABSTRACT
Background: A traumatic arteriovenous fistula of the scalp due to hair transplantation (AVFHT) is a rare fistulous communication between branches of the arteries and draining veins in the scalp's subcutaneous tissue. Its incidence is unknown and its clinical manifestations may range from a pulsatile mass to seldom epilepsy. Surgery and interventional approaches (percutaneous and endovascular embolization) using coils and embolic agents such as Onyx have been used as treatment options. The authors report a rare case of an AVFHT successfully treated through percutaneous and endovascular embolization using coils and precipitating hydrophobic injectable liquid (PHIL) embolic agent. This is possibly the first reported case using PHIL embolic agent to treat an AVFHT. Case Description: The patient presented with a painful and disabling scalp swelling in the right parieto-occipital region 2 years after a hair transplant in 2011. A computed tomography angiography showed an arteriovenous fistula between branches of the right superficial temporal artery and branches of the right occipital artery to the right superficial temporal vein that was successfully embolized using coils and PHIL. The patient was discharged after a smooth recovery and 1 month later remained healthy. Conclusion: Percutaneous and endovascular embolization using PHIL embolic agent can be an alternative treatment for AVFHT.
ABSTRACT
A pneumothorax is the abnormal gas accumulation within the pleural space. We present a case of a patient with an occult iatrogenic pneumothorax who presented with symptomatic anemia that substantially improved after a transfusion, diverting the clinical suspicion. As a result, she developed acute respiratory distress, initially considered secondary to a possible pulmonary embolism vs. fat embolism. After computed tomography confirmed the diagnosis, a chest tube was inserted. This case emphasizes the importance of suspecting pneumothorax secondary to cosmetic procedures and using computed tomography as the first diagnostic tool in complex cases since chest x-rays can miss pneumothorax.
ABSTRACT
Totally implanted central venous port systems are widely used to access central veins for patients needing long-term therapy. These devices have low rates of complications and are commonly used to administer medications like chemotherapeutic agents. Spontaneous rupture of a catheter segment is a rare mechanical complication, usually belatedly diagnosed and presenting with complications. We present a case of a spontaneously ruptured chemotherapy catheter diagnosed using a novel approach via oblique projections on chest X-rays and successfully removed using an endovascular approach.
ABSTRACT
Most known SARS-CoV-2 neutralizing antibodies (nAbs), including those approved by the FDA for emergency use, inhibit viral infection by targeting the receptor-binding domain (RBD) of the spike (S) protein. Variants of concern (VOC) carrying mutations in the RBD or other regions of S reduce the effectiveness of many nAbs and vaccines by evading neutralization. Therefore, therapies that are less susceptible to resistance are urgently needed. Here, we characterized the memory B-cell repertoire of COVID-19 convalescent donors and analyzed their RBD and non-RBD nAbs. We found that many of the non-RBD-targeting nAbs were specific to the N-terminal domain (NTD). Using neutralization assays with authentic SARS-CoV-2 and a recombinant vesicular stomatitis virus carrying SARS-CoV-2 S protein (rVSV-SARS2), we defined a panel of potent RBD and NTD nAbs. Next, we used a combination of neutralization-escape rVSV-SARS2 mutants and a yeast display library of RBD mutants to map their epitopes. The most potent RBD nAb competed with hACE2 binding and targeted an epitope that includes residue F490. The most potent NTD nAb epitope included Y145, K150 and W152. As seen with some of the natural VOC, the neutralization potencies of COVID-19 convalescent sera were reduced by 4-16-fold against rVSV-SARS2 bearing Y145D, K150E or W152R spike mutations. Moreover, we found that combining RBD and NTD nAbs modestly enhanced their neutralization potential. Notably, the same combination of RBD and NTD nAbs limited the development of neutralization-escape mutants in vitro, suggesting such a strategy may have higher efficacy and utility for mitigating the emergence of VOC. ImportanceThe US FDA has issued emergency use authorizations (EUAs) for multiple investigational monoclonal antibody (mAb) therapies for the treatment of mild to moderate COVID-19. These mAb therapeutics are solely targeting the receptor binding domain of the SARS-CoV-2 spike protein. However, the N-terminal domain of the spike protein also carries crucial neutralizing epitopes. Here, we show that key mutations in the N-terminal domain can reduce the neutralizing capacity of convalescent COVID-19 sera. We report that a combination of two neutralizing antibodies targeting the receptor binding and N-terminal domains may have higher efficacy and is beneficial to combat the emergence of virus variants.
ABSTRACT
The COVID-19 global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to place an immense burden on societies and healthcare systems. A key component of COVID-19 control efforts is serologic testing to determine the community prevalence of SARS-CoV-2 exposure and quantify individual immune responses to prior infection or vaccination. Here, we describe a laboratory-developed antibody test that uses readily available research-grade reagents to detect SARS-CoV-2 exposure in patient blood samples with high sensitivity and specificity. We further show that this test affords the estimation of viral spike-specific IgG titers from a single sample measurement, thereby providing a simple and scalable method to measure the strength of an individual's immune response. The accuracy, adaptability, and cost-effectiveness of this test makes it an excellent option for clinical deployment in the ongoing COVID-19 pandemic.
ABSTRACT
The COVID-19 global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to place an immense burden on societies and healthcare systems. A key component of COVID-19 control efforts is serologic testing to determine the community prevalence of SARS-CoV-2 exposure and quantify individual immune responses to prior infection or vaccination. Here, we describe a laboratory-developed antibody test that uses readily available research-grade reagents to detect SARS-CoV-2 exposure in patient blood samples with high sensitivity and specificity. We further show that this test affords the estimation of viral spike-specific IgG titers from a single sample measurement, thereby providing a simple and scalable method to measure the strength of an individuals immune response. The accuracy, adaptability, and cost-effectiveness of this test makes it an excellent option for clinical deployment in the ongoing COVID-19 pandemic.
ABSTRACT
There is an urgent need for vaccines and therapeutics to prevent and treat COVID-19. Rapid SARS-CoV-2 countermeasure development is contingent on the availability of robust, scalable, and readily deployable surrogate viral assays to screen antiviral humoral responses, and define correlates of immune protection, and to down-select candidate antivirals. Here, we describe a highly infectious recombinant vesicular stomatitis virus bearing the SARS-CoV-2 spike glycoprotein S as its sole entry glycoprotein that closely resembles the authentic agent in its entry-related properties. We show that the neutralizing activities of a large panel of COVID-19 convalescent sera can be assessed in high-throughput fluorescent reporter assay with rVSV-SARS-CoV-2 S and that neutralization of the rVSV and authentic SARS-CoV-2 by spike-specific antibodies in these antisera is highly correlated. Our findings underscore the utility of rVSV-SARS-CoV-2 S for the development of spike-specific vaccines and therapeutics and for mechanistic studies of viral entry and its inhibition.
