Carrier-based immobilization of Aerococcus viridansl-lactate oxidase.

l-Lactate oxidase has important applications in biosensing and finds increased use in biocatalysis. The enzyme has been characterized well, yet its immobilization has not been explored in depth. Here, we studied immobilization of Aerococcus viridansl-lactate oxidase on porous carriers of variable matrix material (polymethacrylate, polyurethane, agarose) and surface functional group (amine, Ni2+-loaded nitrilotriacetic acid (NiNTA), epoxide). Carrier activity (Ac) and immobilized enzyme effectiveness (ɳ) were evaluated in dependence of protein loading. Results show that efficient immobilization (Ac: up to 1450 U/g carrier; ɳ: up to 65%) requires a hydrophilic carrier (agarose) equipped with amine groups. The value of ɳ declines sharply as Ac increases, probably due to transition into diffusional regime. Untagged l-lactate oxidase binds to NiNTA carrier similarly as N-terminally His-tagged enzyme. Lixiviation studies reveal quasi-irreversible enzyme adsorption on NiNTA carrier while partial release of activity (≤ 25%) is shown from amine carrier. The desorbed enzyme exhibits the same specific activity as the original l-lactate oxidase. Collectively, our study identifies basic requirements of l-lactate oxidase immobilization on solid carrier and highlights the role of ionic interactions in enzyme-surface adsorption.

Persistence of Anti-SARS-CoV-2 Antibodies in Non-Hospitalized COVID-19 Convalescent Health Care Workers.

Although antibody response to SARS-CoV-2 can be detected early during the infection, several outstanding questions remain to be addressed regarding the magnitude and persistence of antibody titer against different viral proteins and their correlation with the strength of the immune response. An ELISA assay has been developed by expressing and purifying the recombinant SARS-CoV-2 Spike Receptor Binding Domain (RBD), Soluble Ectodomain (Spike), and full length Nucleocapsid protein (N). Sera from healthcare workers affected by non-severe COVID-19 were longitudinally collected over four weeks, and compared to sera from patients hospitalized in Intensive Care Units (ICU) and SARS-CoV-2-negative subjects for the presence of IgM, IgG and IgA antibodies as well as soluble pro-inflammatory mediators in the sera. Non-hospitalized subjects showed lower antibody titers and blood pro-inflammatory cytokine profiles as compared to patients in Intensive Care Units (ICU), irrespective of the antibodies tested. Noteworthy, in non-severe COVID-19 infections, antibody titers against RBD and Spike, but not against the N protein, as well as pro-inflammatory cytokines decreased within a month after viral clearance. Thus, rapid decline in antibody titers and in pro-inflammatory cytokines may be a common feature of non-severe SARS-CoV-2 infection, suggesting that antibody-mediated protection against re-infection with SARS-CoV-2 is of short duration. These results suggest caution in using serological testing to estimate the prevalence of SARS-CoV-2 infection in the general population.

Sources of residuals after endoscopic transsphenoidal surgery for large and giant pituitary adenomas.

BACKGROUND: Giant and large pituitary adenomas (PA) constitute a specific subset of PAs, with gross total resection (GTR) rates frequently not exceeding 50%. Both an anatomical inaccessibility and an inadequate tumor visualization are thought to play a role. This study analyzes risk factors for postoperative residuals after endoscopic transsphenoidal pituitary surgery for large and giant pituitary adenomas. METHODS: A retrospective analysis of patients with giant and large PA operated between 2015 and 2018 was performed. RESULTS: Forty patients (13 females, 27 males) were included in the analysis (30 large and 10 giant PAs). The mean MRI follow-up time was 5.9 ± 6.54 months. Overall, GTR was achieved in 29 patients (72.5%), subtotal resection in 9 (22.5%), and the inconclusive result was in 2 (5%). Unexpected residuals represented 7 (77.7%) of all 9 residual tumors. The most frequent intraoperative factor associated with unexpected residual tumors was improper identification of residual tumor due to obstruction of view in 2 (28.5%) cases and inability to distinguish normal tissue from tumor in the other two (28.5%). Sub-analysis based on tumor size revealed that with large PAs, GTR was achieved in 25 (83.3%), STR in 4 (13.3%), and inconclusive in 1 (3.3%) patient. In patients with giant PAs, GTR was achieved in 4 (40%), STR in 5 (50%), and inconclusive in 1 (10%). Analysis of preoperative factors showed a significant association of residual tumors with larger suprasellar AP distance (p = 0.041), retrosellar extension (p = 0.007), and higher Zurich Score (p = 0.029). CONCLUSION: Large and giant PAs are challenging lesions with high subtotal resection rates. Suprasellar AP distance, retrosellar extension, and higher Zurich Score seem to be significant predictors of degree of resection in these tumors. Improving the intraoperative ability to distinguish tumor from a normal tissue might further decrease the number of unexpected residuals.

Early Data From Case Series of Tracheostomy in Patients With SARS-CoV-2.

Thirty-eight tracheostomies were performed on patients with respiratory failure secondary to SARS-CoV-2 infection over the month of April at North Shore University Hospital and Lenox Hill Hospital (members of Northwell Health System in Long Island and New York City). Follow-up by May 14 revealed that 21 (55.2%) had been weaned from ventilators and 7 (18.4%) underwent decannulation. Two patients (5.3%) expired in the weeks following tracheostomy. Between the 2 institutions, 10 attending surgeons performed all of the tracheostomies using appropriate personal protective equipment, and none demonstrated seroconversion within 1 to 2 weeks of this article.

Powered irrigation with suction evacuation for chronic rhinosinusitis in the office setting: A pilot study.

Bacterial infections in the form of adherent biofilms are frequently implicated in the pathogenesis and recalcitrance of chronic rhinosinusitis. The Hydrodebrider, a disposable powered irrigation and suction device, has been developed specifically to remove biofilm from the paranasal sinuses. We conducted a prospective study to evaluate the tolerability and efficacy of the Hydrodebrider in the office setting with the use of local anesthesia. Of the original 13 adults we recruited, 10 completed the entire study protocol. All enrolled patients had previously undergone sinus surgery that involved the creation of a maxillary antrostomy large enough to allow placement of a Hydrodebrider device, and the endoscopic findings in all patients were consistent with chronic sinusitis. The standard visual analog scale for pain (range: 0 to 10) was used to measure tolerability. The 20-Item Sino-Nasal Outcome Test (SNOT-20) for symptoms was completed at baseline and at 1 and 8 weeks after the procedure. The mean pain score obtained immediately after the procedure was only 2.3, indicating that the procedure was well tolerated. The mean SNOT-20 score trended toward improvement during the first week, but then returned to near-preprocedure levels at 8 weeks. In conclusion, powered irrigation with suction is a well-tolerated procedure in the office setting and might be a useful short-term adjunct in the management of recalcitrant chronic sinusitis.

Expanded Endoscopic Transsphenoidal Resection of Tuberculum Sella Meningioma Invading the Optic Canal.

A 61-year-old male patient presented with recurrent malignant meningioma involving the left optic canal and decreased vision from the left eye. The patient had undergone orbital exenteration on the right 2 years ago. The decision to treat the patient was made based on the significant vision deterioration and rapid tumor growth. Endoscopic transsphenoidal approach considered the most suitable route due to the inferomedial invasion of the optic canal. Gross total removal was achieved and the patient's vision improved postoperatively. The patient developed hydrocephalus 4 weeks postoperatively and cerebrospinal fluid (CSF) leak. Ventriculoperitoneal shunt placement corrected both hydrocephalus and CSF leak. The link to the video can be found at: https://youtu.be/2cOF0pf5gAk .

Pneumatization Patterns of the Petrous Apex and Lateral Sphenoid Recess.

Introduction The petrous apex poses a challenge for surgical intervention due to poor access. As intraoperative image guidance and surgical instrumentation improve, newer endoscopic approaches are increasingly favored. This study aims to provide normative data on the anatomy of the lateral sphenoid sinus recess and petrous apex. These normative data could assist in determining the efficacy of a transnasal transsphenoidal approach to lesions of the anteroinferior petrous apex. Methods This is a retrospective study investigating normative data on all maxillofacial computed tomography (CT) scans performed at a level I trauma center over a 6-month period. All appropriate images had the pneumatization pattern of the petrous apex and lateral recess of the sphenoid sinus reviewed by a single otologist and graded bilaterally. These were then analyzed in SPSS; Pearson correlation analyses and χ 2 test were used. Results A total of 481 patients were identified, yielding a total of 962 temporal bones and sphenoid sinuses for analysis. Eighty-eight percent of sides analyzed had a nonpneumatized lateral recess. The petrous apex was nonpneumatized in 54% of sides analyzed. There was a correlation noted between the degree of pneumatization of the petrous apex and pneumatization of the lateral recess of the sphenoid. Conclusion This study is the first to provide normative data comparing pneumatization of the petrous apex and sphenoid sinus. These data may support future work evaluating the utility of an endonasal approach to the petrous apex.

Multiportal Combined Transorbital and Transnasal Endoscopic Resection of Fibrous Dysplasia.

Introduction Historically, access to the anterior skull base was achieved with open procedures. The paradigms to this approach were challenged with the advent of minimally disruptive endoscopic surgical techniques and supporting technology. The next step in the evolution of minimally disruptive surgery was the combination of multiportal endoscopic surgery. Results The patient was an 18-year-old man who presented with right-sided proptosis. Further diagnostic tests revealed a fibrous dysplasia (FD) occupying the skull base and orbit. The lesion was successfully resected. Conclusions The location of the tumor in this case was challenging, in which surgeons at some centers would have opted to have performed as an open procedure instead of endoscopically. The combined transnasal/transorbital approach is an uncommonly used technique that we have used to remove this tumor successfully. The patient also had a unique disease (FD) in a unique location that was treated without complications. This case report highlights how surgeons may use an expanded armamentarium in dealing with complex pathologies.