Clinical and laboratory characteristics of patients hospitalized with severe COVID-19 in New Orleans, August 2020 to September 2021.

Louisiana experienced high morbidity and mortality from COVID-19. To assess possible explanatory factors, we conducted a cohort study (ClinSeqSer) of patients hospitalized with COVID-19 in New Orleans during August 2020-September 2021. Following enrollment, we reviewed medical charts, and performed SARS-CoV-2 RT-PCR testing on nasal and saliva specimens. We used multivariable logistic regression to assess associations between patient characteristics and severe illness, defined as ≥ 6 L/min oxygen or intubation. Among 456 patients, median age was 56 years, 277 (60.5%) were Black non-Hispanic, 436 (95.2%) had underlying health conditions, and 358 were unvaccinated (92.0% of 389 verified). Overall, 187 patients (40.1%) had severe illness; 60 (13.1%) died during admission. In multivariable models, severe illness was associated with age ≥ 65 years (OR 2.08, 95% CI 1.22-3.56), hospitalization > 5 days after illness onset (OR 1.49, 95% CI 1.01-2.21), and SARS CoV-2 cycle threshold (Ct) result of < 32 in saliva (OR 4.79, 95% CI 1.22-18.77). Among patients who were predominantly Black non-Hispanic, unvaccinated and with underlying health conditions, approximately 1 in 3 patients had severe COVID-19. Older age and delayed time to admission might have contributed to high case-severity. An association between case-severity and low Ct value in saliva warrants further investigation.

Assessing Readiness for Transition From Pediatric to Adult Gender Affirming Care.

PURPOSE: Transitioning from pediatric to adult care is a critical juncture in the health of adolescents. Little is known about how best to optimize transition to adult care among transgender and nonbinary (TGNB) youth. While the Transition Readiness and Assessment Questionnaire (TRAQ) has been validated in other pediatric populations, it has not been studied in TGNB youth. Our aims were to pilot the use of the TRAQ for TGNB patients, describe transition readiness patterns, and identify factors associated with transition readiness. METHODS: The TRAQ was introduced into routine clinical care for patients and their caregivers in a large, urban pediatric gender program in the spring of 2021. We performed a retrospective chart review comparing TRAQ responses based on demographic and clinical data. RESULTS: We collected TRAQs from 153 adolescents (mean age: 19 years [standard deviation 2.36], range: 11-24). The TRAQ demonstrated good internal reliability with a Cronbach alpha of 0.926. Patients scored highest in the TRAQ subdomains of talking with providers and tracking health issues and lowest in the subdomains of managing medications and appointment keeping. Age and presenting to the appointment alone were associated with higher TRAQ scores. DISCUSSION: We found that the TRAQ is internally reliable in a sample of TGNB youth. Factors associated with higher TRAQ scores and patterns identified in TRAQ score subdomains provide an insight into the needs of TGNB youth preparing to transition to adult gender-affirming care. Future research should focus on tracking transition readiness longitudinally, developing and evaluating interventions to improve transition readiness, and assessing post-transition outcomes.

Evaluating Clinical Outcomes of Laparoscopic Subtotal and Total Cholecystectomy for Complicated Acute Cholecystitis: A Systematic Review and Meta-Analysis.

INTRODUCTION: This systematic review and meta-analysis aimed to compare clinical outcomes in patients with complicated acute cholecystitis undergoing laparoscopic total vs subtotal cholecystectomy. METHODS: This systematic review and meta-analysis was conducted according to PRISMA guidelines and queried PubMed, Embase, ProQuest, Google Scholar, and Cochrane databases from inception to May 2023. The primary outcome was complication rates including common bile duct injury, wound infection, reoperation, bile leak, retained stones, and subhepatic collection, whereas secondary outcomes were in-hospital mortality and hospital length of stay. RESULTS: A total of 7 studies with 135,233 cases were included for meta-analysis. Patients who underwent laparoscopic total cholecystectomy had a significantly lower risk of postoperative bile leaks (RR: .15; 95% CI: .03, .80) and subhepatic fluid collection (RR: 0.19; 95% CI: .06, .63) and were 2.94 times less likely to die compared to those who underwent subtotal cholecystectomy (RR .34; 95% CI: .15, .77). Patients who underwent subtotal cholecystectomy had significantly longer hospital length of stay (mean difference 1.0 days; 95% CI: .5 days, 1.4 days). CONCLUSIONS: In adult patients presenting with complicated cholecystitis, management with laparoscopic subtotal cholecystectomy presents a unique complication profile with increased risk of postoperative bile leak and subhepatic fluid collection, in-hospital mortality, and longer hospital length-of-stay when used as an alternative approach to laparoscopic total cholecystectomy. Further research into the most appropriate clinical scenarios and patient populations for the use of the subtotal cholecystectomy approach may prove useful in improving its associated outcomes.

Outcomes of Preperitoneal Packing and Angioembolization for Hemorrhage Control in Hemodynamically Unstable Pelvic Fractures: A Systematic Review and Meta-Analysis.

BACKGROUND: Hemodynamically unstable pelvic fractures are often life-threatening injuries; however, the optimal management remains uncertain. This systematic review and meta-analysis aim to evaluate the most appropriate primary management of hemorrhage in adult patients with hemodynamically unstable pelvic fractures by comparing outcomes following the initial use of preperitoneal packing (PPP) vs angioembolization (AE). METHODS: A systematic search of PubMed, Embase, Google Scholar, and ProQuest databases was conducted following PRISMA guidelines. Studies assessing hemorrhage management in trauma patients with hemodynamically unstable pelvic fractures were included. The data extracted from selected articles included patient demographics, study design, and outcomes such as 24-hour PRBC transfusions, in-hospital mortality, and DVT rate. RESULTS: Eight articles were included in the systematic review. Among the included studies, 2040 patients with hemodynamically unstable pelvic fractures were analyzed. Meta-analyses revealed that treatment with PPP was associated with fewer 24-hour PRBC transfusions (mean difference = -1.0, 95% CI: -1.8 to -.2) than AE. However, no significant differences were noted in in-hospital mortality (RR: .91, 95% CI: .80-1.05) and the rate of deep vein thrombosis (RR: .89, 95% CI: .62-1.28) between groups. CONCLUSION: The findings of this study suggest that primary management with PPP was associated with fewer 24-hour PRBC transfusions compared to AE. The choice of primary management with PPP or AE did not significantly impact in-hospital mortality. Future studies should address clinical outcomes and the factors that affect them to better understand the impact of different management strategies and direct the creation of practice management guidelines.

Myeloid cell-derived creatine in the hypoxic niche promotes glioblastoma growth.

Glioblastoma (GBM) is a malignancy dominated by the infiltration of tumor-associated myeloid cells (TAMCs). Examination of TAMC metabolic phenotypes in mouse models and patients with GBM identified the de novo creatine metabolic pathway as a hallmark of TAMCs. Multi-omics analyses revealed that TAMCs surround the hypoxic peri-necrotic regions of GBM and express the creatine metabolic enzyme glycine amidinotransferase (GATM). Conversely, GBM cells located within these same regions are uniquely specific in expressing the creatine transporter (SLC6A8). We hypothesized that TAMCs provide creatine to tumors, promoting GBM progression. Isotopic tracing demonstrated that TAMC-secreted creatine is taken up by tumor cells. Creatine supplementation protected tumors from hypoxia-induced stress, which was abrogated with genetic ablation or pharmacologic inhibition of SLC6A8. Lastly, inhibition of creatine transport using the clinically relevant compound, RGX-202-01, blunted tumor growth and enhanced radiation therapy in vivo. This work highlights that myeloid-to-tumor transfer of creatine promotes tumor growth in the hypoxic niche.

The Association Between Gender and Clinical Outcomes in Patients With Moderate to Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

INTRODUCTION: Traumatic brain injuries (TBIs) are a significant cause of morbidity and mortality in the United States. but have a disproportionate impact on patients based on gender. This systematic review and meta-analysis aim to compare gender differences in clinical outcomes between male and female adult trauma patients with moderate and severe TBI. METHODS: Studies assessing gender differences in outcomes following TBIs on PubMed, Google Scholar, EMBASE, and ProQuest were searched. Meta-analysis was performed for outcomes including in-hospital mortality, hospital length of stay, intensive care unit length of stay, and Glasgow outcome scale (GOS) at 6 mo. RESULTS: Eight studies were included for analysis with 26,408 female and 63,393 male patients. Meta-analysis demonstrated that males had a significantly lower risk of mortality than females (RR: 0.88; 95% CI 0.78, 0.99; P = 0.0001). Females had a shorter hospital length of stay (mean difference -1.4 d; 95% CI - 1.6 d, -1.2 d). No significant differences were identified in intensive care unit length of stay (mean difference -3.0 d; 95% CI -7.0 d, 1.1 d; P = 0.94) or GOS at 6 mo (mean difference 0.2 d; 95% CI -0.9 d, 1.4 d; P = 1). CONCLUSIONS: Compared to male patients, female patients with moderate and severe TBI had a significantly higher in-hospital mortality risk. There were no significant differences in long-term outcomes between genders based on GOS at 6 mo. These findings warrant further investigation into the etiology of these gender disparities and their impact on additional clinical outcome measures.

No Increase in Symptoms Toward the End of the Ocrelizumab Infusion Cycle in Patients With Multiple Sclerosis: Symptom Burden on Ocrelizumab: A Longitudinal Study (SymBOLS).

Background and Objectives: Some patients with multiple sclerosis (MS) receiving ocrelizumab (OCR) report worsening symptoms toward the end of the 6-month infusion cycle ('wearing off'). The objective of our study was to comprehensively assess changes in symptom burden across 2 consecutive OCR infusion cycles. Methods: SYMptom Burden on Ocrelizumab, a Longitudinal Study (SymBOLS; NCT04855617) was an investigator-initiated, 2-center study of patients with MS starting or receiving OCR. Patients' symptoms were assessed with NeuroQoL short forms, SymptoMScreen, and Work Productivity and Activity Impairment Questionnaire at the start-cycle, mid-cycle, and end-cycle time points in each of the 2 infusion cycles. Symptom scores at the 3 time points within each cycle were compared with repeated-measures ANOVA or the Friedman rank-sum test for non-normal variables. The proportions of patients with a meaningful symptomatic change from the start to the end of each infusion cycle were calculated, and patients whose symptoms improved, worsened, and stayed the same from the start to the end of the cycle were compared with respect to demographic and clinical characteristics. Results: One hundred three patients with MS provided longitudinal data for analyses (mean age [SD]: 46.7 [12.2] years, 68% female, 33% non-White, disease duration: 15.5 [5] years, 41% with the Extended Disability Status Scale score >3). On a group level, NeuroQoL and SymptoMScreen scores mostly remained stable or even improved slightly toward the end of each cycle. On an individual level, symptoms remained unchanged across either cycle for most patients, and meaningful symptom worsening from the start to the end of the cycle was no more common than improvement. Meaningful change in symptoms in both cycles was very rare and generally in the direction of improvement toward the end cycle. Despite the lack of evidence for symptom worsening with a longer time from infusion, 54% of patients endorsed feeling of "wearing off" at least sometimes, most commonly as an increase in fatigue. Discussion: Our prospective study failed to uncover evidence for the worsening of symptoms with a longer time from OCR infusion. These findings cast doubt on the existence of wearing off as a physiologic phenomenon in OCR-treated patients with MS. The perception of wearing off is likely the result of natural fluctuations in MS symptoms and attribution bias.

Novel Surfactant Compatibility with Downstream Protein Bioprocesses.

Downstream processing of antibodies consists of a series of steps aimed at purifying the product and ensuring it is delivered to formulators structurally and functionally intact. The process can be complex and time-consuming, involving multiple filtrations, chromatography, and buffer exchange steps that can interfere with product integrity. This study explores the possibility and benefits of adding N-myristoyl phenylalanine polyether amine diamide (FM1000) as a process aid. FM1000 is a nonionic surfactant that is highly effective at stabilizing proteins against aggregation and particle formation and has been extensively explored as a novel excipient for antibody formulations. In this work, FM1000 is shown to stabilize proteins against pumping-induced aggregation which can occur while transporting them between process units and within certain processes. It is also shown to prevent antibody fouling of multiple polymeric surfaces. Furthermore, FM1000 can be removed after some steps and during buffer exchange in ultrafiltration/diafiltration, if needed. Additionally, FM1000 was compared to polysorbates in studies focusing on surfactant retention on filters and columns. While the different molecular entities of polysorbates elute at different rates, FM1000 flows through purification units as a single molecule and at a faster rate. Overall, this work defines new areas of application for FM1000 within downstream processing and presents it as a versatile process aid, where its addition and removal are tunable depending on the needs of each product.

Generation of B-cell-based cellular vaccine for cancer in murine models.

A B-cell-based cellular vaccine (BVax), produced from 4-1BBL+ B cells, can select tumor-specific B cells that, upon ex vivo culture, can generate tumor-specific antibodies and activate T cells. Here, we present a protocol to generate a B-cell-based vaccine in a CT2A orthotopic glioma murine model. We describe steps for BVax production involving glioma cell implantation, tissue harvesting, 4-1BBL+ B cell isolation, and activation. We also describe assessing BVax phenotype in vitro and in vivo functional status. For complete details on the use and execution of this protocol, please refer to Lee-Chang et al. (2021).1.

CAB versus ABC approach for resuscitation of patients following traumatic injury: Toward improving patient safety and survival.

INTRODUCTION: Though a circulation-airway-breathing (CAB) resuscitation sequence is now widely accepted in administering CPR over the airway-breathing-circulation (ABC) sequence following cardiac arrest, current evidence and guidelines vary considerably for complex polytraumas, with some prioritizing management of the airway and others advocating for initial treatment of hemorrhage. This review aims to evaluate existing literature comparing ABC and CAB resuscitation sequences in adult trauma patients in-hospital to direct future research and guide evidence-based recommendations for management. METHODS: A literature search was conducted on PubMed, Embase, and Google Scholar until September 29, 2022. Articles were assessed for comparison between CAB and ABC resuscitation sequences, adult trauma patients, in-hospital treatment, patient volume status, and clinical outcomes. RESULTS: Four studies met the inclusion criteria. Two studies compared the CAB and ABC sequences specifically in hypotensive trauma patients, one study evaluated the sequences in trauma patients with hypovolemic shock, and one study in patients with all types of shock. Hypotensive trauma patients who underwent rapid sequence intubation before blood transfusion had a significantly higher mortality rate than those who had blood transfusion initiated first (50 vs 78% P < 0.05) and a significant drop in blood pressure. Patients who subsequently experienced post-intubation hypotension (PIH) had increased mortality over those without PIH. overall mortality was higher in patients that developed PIH (mortality, n (%): PIH = 250/753 (33.2%) vs 253/1291 (19.6%), p < 0.001). CONCLUSION: This study found that hypotensive trauma patients, especially those with active hemorrhage, may benefit more from a CAB approach to resuscitation, as early intubation may increase mortality secondary to PIH. However, patients with critical hypoxia or airway injury may still benefit more from the ABC sequence and prioritization of the airway. Future prospective studies are needed to understand the benefits of CAB with trauma patients and identify which patient subgroups are most affected by prioritizing circulation before airway management.

B-cells Drive Response to PD-1 Blockade in Glioblastoma Upon Neutralization of TGFß-mediated Immunosuppression.

Immunotherapy has revolutionized cancer treatment but has yet to be translated into brain tumors. Studies in other solid tumors suggest a central role of B-cell immunity in driving immune-checkpoint-blockade efficacy. Using single-cell and single-nuclei transcriptomics of human glioblastoma and melanoma brain metastasis, we found that tumor-associated B-cells have high expression of checkpoint molecules, known to block B-cell-receptor downstream effector function such as plasmablast differentiation and antigen-presentation. We also identified TGFß-1/TGFß receptor-2 interaction as a crucial modulator of B-cell suppression. Treatment of glioblastoma patients with pembrolizumab induced expression of B-cell checkpoint molecules and TGFß-receptor-2. Abrogation of TGFß using different conditional knockouts expanded germinal-center-like intratumoral B-cells, enhancing immune-checkpoint-blockade efficacy. Finally, blocking αVß8 integrin (which controls the release of active TGFß) and PD-1 significantly increased B-cell-dependent animal survival and immunological memory. Our study highlights the importance of intratumoral B-cell immunity and a remodeled approach to boost the effects of immunotherapy against brain tumors.

The CXCL16-CXCR6 axis in glioblastoma modulates T-cell activity in a spatiotemporal context.

Introduction: Glioblastoma multiforme (GBM) pathobiology is characterized by its significant induction of immunosuppression within the tumor microenvironment, predominantly mediated by immunosuppressive tumor-associated myeloid cells (TAMCs). Myeloid cells play a pivotal role in shaping the GBM microenvironment and influencing immune responses, with direct interactions with effector immune cells critically impacting these processes. Methods: Our study investigates the role of the CXCR6/CXCL16 axis in T-cell myeloid interactions within GBM tissues. We examined the surface expression of CXCL16, revealing its limitation to TAMCs, while microglia release CXCL16 as a cytokine. The study explores how these distinct expression patterns affect T-cell engagement, focusing on the consequences for T-cell function within the tumor environment. Additionally, we assessed the significance of CXCR6 expression in T-cell activation and the initial migration to tumor tissues. Results: Our data demonstrates that CXCL16 surface expression on TAMCs results in predominant T-cell engagement with these cells, leading to impaired T-cell function within the tumor environment. Conversely, our findings highlight the essential role of CXCR6 expression in facilitating T-cell activation and initial migration to tumor tissues. The CXCL16-CXCR6 axis exhibits dualistic characteristics, facilitating the early stages of the T-cell immune response and promoting T-cell infiltration into tumors. However, once inside the tumor, this axis contributes to immunosuppression. Discussion: The dual nature of the CXCL16-CXCR6 axis underscores its potential as a therapeutic target in GBM. However, our results emphasize the importance of carefully considering the timing and context of intervention. While targeting this axis holds promise in combating GBM, the complex interplay between TAMCs, microglia, and T cells suggests that intervention strategies need to be tailored to optimize the balance between promoting antitumor immunity and preventing immunosuppression within the dynamic tumor microenvironment.

Antigen-presenting B cells promote TCF-1+ PD1- stem-like CD8+ T-cell proliferation in glioblastoma.

Understanding the spatial relationship and functional interaction of immune cells in glioblastoma (GBM) is critical for developing new therapeutics that overcome the highly immunosuppressive tumor microenvironment. Our study showed that B and T cells form clusters within the GBM microenvironment within a 15-µm radius, suggesting that B and T cells could form immune synapses within the GBM. However, GBM-infiltrating B cells suppress the activation of CD8+ T cells. To overcome this immunosuppression, we leveraged B-cell functions by activating them with CD40 agonism, IFNγ, and BAFF to generate a potent antigen-presenting B cells named BVax. BVax had improved antigen cross-presentation potential compared to naïve B cells and were primed to use the IL15-IL15Ra mechanism to enhance T cell activation. Compared to naïve B cells, BVax could improve CD8 T cell activation and proliferation. Compared to dendritic cells (DCs), which are the current gold standard professional antigen-presenting cell, BVax promoted highly proliferative T cells in-vitro that had a stem-like memory T cell phenotype characterized by CD62L+CD44- expression, high TCF-1 expression, and low PD-1 and granzyme B expression. Adoptive transfer of BVax-activated CD8+ T cells into tumor-bearing brains led to T cell reactivation with higher TCF-1 expression and elevated granzyme B production compared to DC-activated CD8+ T cells. Adoptive transfer of BVax into an irradiated immunocompetent tumor-bearing host promoted more CD8+ T cell proliferation than adoptive transfer of DCs. Moreover, highly proliferative CD8+ T cells in the BVax group had less PD-1 expression than those highly proliferative CD8+ T cells in the DC group. The findings of this study suggest that BVax and DC could generate distinctive CD8+ T cells, which potentially serve multiple purposes in cellular vaccine development.

Heart-Kidney Transplantation in a Transgender Woman.

We describe the care of a transgender woman with heart failure who underwent heart-kidney transplantation. Perioperative management of hormone therapy, considerations for future gender-affirming surgeries, and psychosocial aspects of care are discussed. Interdisciplinary collaboration is essential in the treatment of patients with advanced heart failure in the setting of gender-affirming therapies. (Level of Difficulty: Advanced.).

Stereoelectroencephalography before 2 years of age.

OBJECTIVE: Stereoelectroencephalography (SEEG) is a widely used technique for localizing seizure onset zones prior to resection. However, its use has traditionally been avoided in children under 2 years of age because of concerns regarding pin fixation in the immature skull, intraoperative and postoperative electrode bolt security, and stereotactic registration accuracy. In this retrospective study, the authors describe their experience using SEEG in patients younger than 2 years of age, with a focus on the procedure's safety, feasibility, and accuracy as well as surgical outcomes. METHODS: A retrospective review of children under 2 years of age who had undergone SEEG while at Children's Hospital of Philadelphia between November 2017 and July 2021 was performed. Data on clinical characteristics, surgical procedure, imaging results, electrode accuracy measurements, and postoperative outcomes were examined. RESULTS: Five patients younger than 2 years of age underwent SEEG during the study period (median age 20 months, range 17-23 months). The mean age at seizure onset was 9 months. Developmental delay was present in all patients, and epilepsy-associated genetic diagnoses included tuberous sclerosis (n = 1), KAT6B (n = 1), and NPRL3 (n = 1). Cortical lesions included tubers from tuberous sclerosis (n = 1), mesial temporal sclerosis (n = 1), and cortical dysplasia (n = 3). The mean number of placed electrodes was 11 (range 6-20 electrodes). Bilateral electrodes were placed in 1 patient. Seizure onset zones were identified in all cases. There were no SEEG-related complications, including skull fracture, electrode misplacement, hemorrhage, infection, cerebrospinal fluid leakage, electrode pullout, neurological deficit, or death. The mean target point error for all electrodes was 1.0 mm. All patients proceeded to resective surgery, with a mean follow-up of 21 months (range 8-53 months). All patients attained a favorable epilepsy outcome, including Engel class IA (n = 2), IC (n = 1), ID (n = 1), and IIA (n = 1). CONCLUSIONS: SEEG can be safely, accurately, and effectively utilized in children under age 2 with good postoperative outcomes using standard SEEG equipment. With minimal modification, this procedure is feasible in those with immature skulls and guides the epilepsy team's decision-making for early and optimal treatment of refractory epilepsy through effective localization of seizure onset zones.

BRAINterns 2.0: Durability of Webinar-Based Education and Social Media Beyond the Coronavirus Disease 2019 Pandemic.

BACKGROUND: Webinars offer novel educational opportunities beyond those of traditional, in-person experiences. BRAINterns is an open-access webinar-based education platform created to replace opportunities lost during the coronavirus disease 2019 pandemic. This program previously showed the efficacy of webinars to expand access to careers in medicine, and in particular, neurosurgery. BRAINterns 2.0 was established to assess the durability of Web-based learning. METHODS: A modified 4-week webinar series was held during July 2021. A retrospective exit survey was distributed to participants and responses analyzed. RESULTS: A total of 16,045 people registered for BRAINterns 2.0, representing 103 countries. Survey responses were received from 3765 participants (23% response rate). New, first-time registrants comprised 66% of participants, with the rest being returning participants. A total of 342 students participated in a dedicated module delivered entirely in Spanish. Females represented 81% of respondents. Participants identified that desirable elements of the program were opportunities to hear from women (53%) and people of color (44%) in health care. Participants heard about the series through TikTok (n = 1251; 33%), Instagram (n = 1109; 29%), Facebook (n = 637; 17%), and word of mouth (n = 708; 19%) with assistance from an ambassador program. CONCLUSIONS: Webinar-based education programs continue to be of interest to students in an increasingly digital world. Social media, and specifically the use of educational ambassadors, are effective to improve visibility of educational programs across a diverse population of students. Understanding the desires of participants is critical to building a successful online education platform.

Differential Surface Adsorption Phenomena for Conventional and Novel Surfactants Correlates with Changes in Interfacial mAb Stabilization.

Protein adsorption on surfaces can result in loss of drug product stability and efficacy during the production, storage, and administration of protein-based therapeutics. Surface-active agents (excipients) are typically added in protein formulations to prevent undesired interactions of proteins on surfaces and protein particle formation/aggregation in solution. The objective of this work is to understand the molecular-level competitive adsorption mechanism between the monoclonal antibody (mAb) and a commercially used excipient, polysorbate 80 (PS80), and a novel excipient, N-myristoyl phenylalanine-N-polyetheramine diamide (FM1000). The relative rate of adsorption of PS80 and FM1000 was studied by pendant bubble tensiometry. We find that FM1000 saturates the interface faster than PS80. Additionally, the surface-adsorbed amounts from X-ray reflectivity (XRR) measurements show that FM1000 blocks a larger percentage of interfacial area than PS80, indicating that a lower bulk FM1000 surface concentration is sufficient to prevent protein adsorption onto the air/water interface. XRR models reveal that with an increase in mAb concentration (0.5-2.5 mg/mL: IV based formulations), an increased amount of PS80 concentration (below critical micelle concentration, CMC) is required, whereas a fixed value of FM1000 concentration (above its relatively lower CMC) is sufficient to inhibit mAb adsorption, preventing mAb from co-existing with surfactants on the surface layer. With this observation, we show that the CMC of the surfactant is not the critical factor to indicate its ability to inhibit protein adsorption, especially for chemically different surfactants, PS80 and FM1000. Additionally, interface-induced aggregation studies indicate that at minimum surfactant concentration levels in protein formulations, fewer protein particles form in the presence of FM1000. Our results provide a mechanistic link between the adsorption of mAbs at the air/water interface and the aggregation induced by agitation in the presence of surfactants.

Stereoelectroencephalography in the very young: Case report.

Stereoelectroencephalography (SEEG) is an increasingly popular invasive monitoring approach to epilepsy surgery in patients with drug-resistant epilepsies. The technique allows a three-dimensional definition of the epileptogenic zones (EZ) in the brain. It has been shown to be safe and effective in adults and older children but has been used sparingly in children less than two years old due to concerns about pin fixation in thin bone, registration accuracy, and bolt security. As such, most current series of pediatric invasive EEG explorations do not include young participants, and, when they do, SEEG is often not utilized for these patients. Recent national survey data further suggests SEEG is infrequently utilized in very young patients. We present a novel case of SEEG used to localize the EZ in a 17-month-old patient with thin cranial bone, an open fontanelle, and severe drug-resistant epilepsy due to tuberous sclerosis complex (TSC), with excellent accuracy, surgical results, and seizure remission.

Gelation under stress: impact of shear flow on the formation and mechanical properties of methylcellulose hydrogels.

We demonstrate that small unidirectional applied-stresses during temperature-induced gelation dramatically change the gel temperature and the resulting mechanical properties and structure of aqueous methylcellulose (MC), a material that forms a brittle gel with a fibrillar microstructure at elevated temperatures. Applied stress makes gelation more difficult, evidenced by an increased gelation temperature, and weakens mechanical properties of the hot gel, evidenced by a decreased elastic modulus and decreased apparent failure stress. In extreme cases, formation of a fully percolated polymer network is inhibited and a soft granular yield-stress fluid is formed. We quantify the effects of the applied stress using a filament-based mechanical model to relate the measured properties to the structural features of the fibril network. The dramatic changes in the gel temperature and hot gel properties give more design freedom to processing-dependent rheology, but could be detrimental to coating applications where gravitational stress during gelation is unavoidable.

Emerging Challenges and Innovations in Surfactant-mediated Stabilization of Biologic Formulations.

Biologics may be subjected to various destabilizing conditions during manufacturing, transportation, storage, and use. Therefore, biologics must be appropriately formulated to meet their desired quality target product profiles. In the formulations of protein-based biologics, one critical component is surfactant. Polysorbate 80 and Polysorbate 20 remain the most commonly used surfactants. Surfactants can stabilize proteins through different mechanisms and help the proteins withstand destabilization stresses. However, the challenges associated with surfactants, for instance, impurities, degradation, and potential triggering of adverse immune responses, have been encountered. Therefore, there are continued efforts to develop novel surfactants to overcome these challenges associated with traditional surfactants. Meanwhile, surfactants have also found their use in formulations of newer and novel modalities, namely, antibody-drug conjugates, bispecific antibodies, and adeno-associated viruses (AAV). This review provides an updated in-depth discussion of surfactants in the above-mentioned areas, namely mechanism of action of surfactants, a critical review of challenges with surfactants and current mitigation approaches, and emerging technologies to develop novel surfactants. In addition, gaps, current mitigations, and future directions have been presented to trigger further discussion and research to facilitate the use and development of novel surfactants.