Unified and Versatile Multiplex Platform for Expedited Method Development and Comprehensive Characterization of Therapeutic Peptides.

Agile analytical approaches are needed for fast and comprehensive characterization of peptide drug candidates. In this study, a unified and versatile multiplex platform was developed to expedite method development and enable the routine determination of multiple quality attributes simultaneously. The platform integrates the automation of size exclusion chromatography (SEC), reversed phase liquid chromatography coupled to reversed phase liquid chromatography (RPLC-RPLC), and hydrophilic interaction liquid chromatography hyphenated to charged aerosol detection (HILIC-CAD). Various therapeutic peptide constructs, including macrocyclic peptides and disulfide constrained peptides, across different lots were studied. The effect of the mobile phase acetonitrile content on the impurity profiles was systematically studied using two SEC columns. A prototype MaxPeak Premier SEC 125 Å column packed with BEH PEO particles achieved the separation of impurities (>2.0% area), whereas no impurities could be observed with an ACQUITY UPLC Protein BEH SEC 125 Å column packed with BEH diol particles. Comprehensive impurity profiling and expedited method development was performed utilizing RPLC-RPLC. Each peptide was analyzed by a combination of 12 conditions in the second dimension, using four columns with octadecyl, phenyl-hexyl, and cyano bonded phases, and three mobile phases with various solvents, modifiers, and pH compositions. Additionally, a HILIC-CAD method was developed for the quantification of TFA, commonly present in peptide products.

Analytical and Functional Characterization of Plasmid DNA Topological Forms and Multimers.

Plasmid DNA (pDNA) is an essential tool in genetic engineering that has gained prevalence in cell and gene therapies. Plasmids exist as supercoiled (SC), open circular (OC), and linear forms. Plasmid multimerization can also occur during the manufacturing process. Even though the SC forms are thought to provide optimal knock-in (KI) efficiency, there is no strong consensus on the effect of the topological forms and multimers on the functional activity. In addition, the results obtained for conventional pDNAs (>5 kbp) do not necessarily translate to smaller pDNAs (∼3 kbp). In this study, a workflow was developed for the analytical and functional characterization of pDNA topological forms and multimers. An anion exchange chromatography (AEC) method was first developed to quantify the topological forms and multimers. Four AEC columns were initially compared, one of which was found to provide superior chromatographic performance. The effect of mobile phase pH, various salts, column temperature, and acetonitrile content on the separation performance was systematically studied. The method performance, including precision and accuracy, was evaluated. The final AEC method was compared to capillary gel electrophoresis (CGE) by analyzing several pDNA sequences and lots. A forced degradation study revealed unexpectedly high degradation of the SC forms. Finally, the KI efficiency was compared for the SC and OC forms, and the multimers.

Barriers to Antiplatelet and Statin Adherence Following Major Vascular Intervention.

BACKGROUND: Antiplatelets and statins therapies are associated with improved cardiovascular outcomes following major vascular intervention. Many vascular surgery institutions are reporting improved prescribing rates for aspirin (ASA), P2Y12 antagonists, and statins. Nevertheless, there remains limited publication describing rates and patient-perceived barriers for postoperative adherence. The purpose of this study is to investigate patient nonadherence to antiplatelet and statin therapies following major vascular intervention. METHODS: A retrospective review of patients who underwent major vascular intervention at a single academic center was performed. The prescribing rates of ASA, P2Y12 antagonists, and statins were reviewed. Postoperative adherence, defined as consistent intake as prescribed, was evaluated at 1, 3, 6, 9, and 12 months using electronic documentation of both follow-up clinic appointments and phone call assessments, then corroborated with pharmacy fulfilment records. Patient-reported barriers to medication adherence were also examined. RESULTS: A total of 101 subjects underwent major vascular intervention between January 2020 and July 2020, 98% of whom were discharged on at least 1 antiplatelet or statin agent. Approximately 90% of patients were discharged with ASA, 32% with a P2Y12 antagonist, and 96% with a statin. All patients who maintained adherence up to 6 months continued to report adherence at 9 and 12 months. Consistent adherence at 12 months was documented in 76% of patients on ASA, 81% on P2Y12 antagonism therapy, and 73% on statins. New adverse drug reactions represented the most common barrier to achieving adherence (37% [n = 20]). Preoperative therapy with ASA, P2Y12 antagonists, and statins were all independently predictive of postoperative adherence to the same regimen (P ≤ 0.001). The female gender was also associated with higher rates of adherence to postoperative P2Y12 antagonism therapy (P ≤ 0.05). CONCLUSIONS: The current prescribing rates for antiplatelet and statin agents are promising, but postoperative nonadherence remains a multifaceted issue.

Early mortality in acute myeloid leukemia with KMT2A rearrangement is associated with high risk of bleeding and disseminated intravascular coagulation.

BACKGROUND: Acute myeloid leukemia (AML) with rearrangement of lysine methyltransferase 2a gene (KMT2Ar) is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity. METHODS: In a retrospective analysis, causes and rates of early mortality following induction treatment were compared between a cohort of adults with KMT2Ar AML (N = 172) and an age-matched cohort of patients with normal karyotype AML (N = 522). RESULTS: The 60-day mortality in patients with KMT2Ar AML was 15% compared with 7% with normal karyotype (p = .04). We found a significantly higher occurrence of major bleeding events (p = .005) and total bleeding events (p = .001) in KMT2Ar AML compared with diploid AML. Among evaluable patients with KMT2Ar AML, 93% exhibited overt disseminated intravascular coagulopathy compared with 54% of patients with a normal karyotype before death (p = .03). In a multivariate analysis, KMT2Ar and a monocytic phenotypic were the only independent predictors of any bleeding event in patients who died within 60 days (odds ratio, 3.5; 95% CI, 1.4-10.4; p = .03; odds ratio, 3.2; 95% CI, 1-1-9.4; p = .04, respectively). CONCLUSION: In conclusion, early recognition and aggressive management of disseminated intravascular coagulopathy and coagulopathy are important considerations that could mitigate the risk of death during induction treatment in KMT2Ar AML. PLAIN LANGUAGE SUMMARY: Acute myeloid leukemia (AML) with rearrangement of KMT2A is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity. In this article, that KMT2A-rearranged AML is demonstrably associated with higher early mortality and an increased risk of bleeding and coagulopathy, specifically, disseminated intravascular coagulation, compared with normal karyotype AML. These findings emphasize the importance of monitoring and mitigating coagulopathy in KMT2A-rearranged leukemia similar to what is done in acute promyelocytic leukemia.

Separation of Plasmid DNA Topological Forms, Messenger RNA, and Lipid Nanoparticle Aggregates Using an Ultrawide Pore Size Exclusion Chromatography Column.

Health authorities have highlighted the need to determine oligonucleotide aggregates. However, existing technologies have limitations that have prevented the reliable analysis of size variants for large nucleic acids and lipid nanoparticles (LNPs). In this work, nucleic acid and LNP aggregation was examined using prototype, low adsorption ultrawide pore size exclusion chromatography (SEC) columns. A preliminary study was conducted to determine the column's physicochemical properties. A large difference in aggregate content (17.8 vs 59.7 %) was found for a model messenger RNA (mRNA) produced by different manufacturers. We further investigated the nature of the aggregates via a heat treatment. Interestingly, thermal stress irreversibly decreased the amount of aggregates from 59.7 to 4.1% and increased the main peak area 3.3-fold. To the best of our knowledge, for the first time, plasmid DNA topological forms and multimers were separated by analytical SEC. The degradation trends were compared to the data obtained with an anion exchange chromatography method. Finally, unconjugated and fragment antigen-binding (Fab)-guided LNPs were analyzed and their elution times were plotted against their sizes as measured by DLS. Multi-angle light scattering (MALS) was coupled to SEC in order to gain further insights on large species eluting before the LNPs, which were later identified as self-associating LNPs. This study demonstrated the utility of ultrawide pore SEC columns in characterizing the size variants of large nucleic acid therapeutics and LNPs.

Long-term aircraft noise exposure and risk of hypertension in postmenopausal women.

BACKGROUND: Studies of the association between aircraft noise and hypertension are complicated by inadequate control for potential confounders and a lack of longitudinal assessments, and existing evidence is inconclusive. OBJECTIVES: We evaluated the association between long-term aircraft noise exposure and risk of hypertension among post-menopausal women in the Women's Health Initiative Clinical Trials, an ongoing prospective U.S. METHODS: Day-night average (DNL) and night equivalent sound levels (Lnight) were modeled for 90 U.S. airports from 1995 to 2010 in 5-year intervals using the Aviation Environmental Design Tool and linked to participant geocoded addresses from 1993 to 2010. Participants with modeled exposures ≥45 A-weighted decibels (dB [A]) were considered exposed, and those outside of 45 dB(A) who also did not live in close proximity to unmodeled airports were considered unexposed. Hypertension was defined as systolic/diastolic blood pressure ≥140/90 mmHg or inventoried/self-reported antihypertensive medication use. Using time-varying Cox proportional hazards models, we estimated hazard ratios (HRs) for incident hypertension when exposed to DNL or Lnight ≥45 versus <45 dB(A), controlling for sociodemographic, behavioral, and environmental/contextual factors. RESULTS/DISCUSSION: There were 18,783 participants with non-missing DNL exposure and 14,443 with non-missing Lnight exposure at risk of hypertension. In adjusted models, DNL and Lnight ≥45 db(A) were associated with HRs of 1.00 (95% confidence interval [CI]: 0.93, 1.08) and 1.06 (95%CI: 0.91, 1.24), respectively. There was no evidence supporting a positive exposure-response relationship, and findings were robust in sensitivity analyses. Indications of elevated risk were seen among certain subgroups, such as those living in areas with lower population density (HRinteraction: 0.84; 95%CI: 0.72, 0.98) or nitrogen dioxide concentrations (HRinteraction: 0.82; 95%CI: 0.71, 0.95), which may indicate lower ambient/road traffic noise. Our findings do not suggest a relationship between aircraft noise and incident hypertension among older women in the U.S., though associations in lower ambient noise settings merit further investigation.

Treadmill running intensity and post-exercise increase in plasma cardiac troponin I and T-A pilot study in healthy volunteers.

BACKGROUND: Plasma concentrations of cardiac troponins increase in healthy individuals after strenuous training, but the response to lower exercise intensities has not been characterized. AIM: To determine whether exercise at moderate intensity significantly increases plasma cardiac troponins measured with different assays in healthy recreational athletes. METHODS: Twenty-four self-reported healthy volunteers were instructed to complete three 60-min bouts of treadmill running at variable intensities: High-intensity training (HIT) including a maximal exercise test and an anaerobic threshold test followed by training at 80%-95% of maximum heart rate (HRmax ), Moderate-intensity training (MIT) at 60%-75% of HRmax , and Low-intensity training (LIT) at 45%-55% of HRmax . Blood samples were collected before and at 2, 4, and 6 h after HIT and 4 h after MIT and LIT. Troponin I and T were measured in plasma samples with assays from Abbot, Siemens, and Roche. RESULTS: Plasma troponins measured with all assays were significantly increased compared to baseline after HIT but not after LIT. After HIT, the fraction of all participants with one or more values above the assay-specific 99th percentiles ranged from 13% to 61%. The biomarker criteria for acute myocardial injury were met after HIT for troponin T in 75% of female participants having no clinical evidence of coronary artery disease. CONCLUSION: High-intensity, but not moderate- or low-intensity, training for 60 min induced a potentially clinically significant increase in plasma cardiac troponins in healthy volunteers. Results exceeding the population 99th percentiles were most frequent with the troponin T assay.

Pott's Puffy: First Shot is the Best Shot.

OBJECTIVE: Low incidence of Pott's Puffy tumor (PPT) has caused studying risk factors and recurrences of the disease to be difficult. We used the comparatively increased incidence at our institution to evaluate potential risk factors for the disease process itself and prognostic factors for recurrence of the disease. METHODS: Single institutional retrospective chart review identified 31 patients from 2010 to 2022 with PPT compared with a control group of 20 patients with either chronic rhinosinusitis or recurrent sinusitis. Patient mean age of PPT was 42 (range of 5 to 90) with the majority of the patient population as male (74%) and Caucasian (68%) in the setting of rural West Texas. Patient mean age of the control group was 50.7 (range of 30-78) with majority of patient population as male (55%) and Caucasian (70%). Interventions studied were functional endoscopic sinus surgery (FESS), FESS with trephination, and cranialization with or without FESS to compare prognostic factors for recurrence rates of PPT. These patients' prognostic risk factors for recurrence and risk factors to develop PPT were analyzed using Analysis of Variance (ANOVA) χ 2 statistical analysis with Fischer exact testing. RESULTS: Mean age was 42 years (range of 5-90) with the majority of the PPT patient population as male (74%) and Caucasian (68%) with an overall incidence of about 1 in 300,000. Pott's Puffy tumor patients were significantly favored in the younger and male population compared with the control patients. Risk factors of no prior allergy diagnosis, previous trauma, medication allergy to penicillin class or cephalosporin class, and lower body mass index were significant in the PPT population compared with the control group. Significant prognostic factors for recurrence of PPT were prior history of sinus surgery and operative treatment choice. Fifty percent (3/6) of patients with prior sinus surgery had recurrence of PPT. Of our 4 treatment options (FESS, FESS with trephination, FESS with cranialization, or cranialization alone), ;FESS had a recurrence of PPT of 0% (0/13), FESS with trephination had a recurrence of PPT of 50% (3/6), FESS with cranialization had a recurrence of PPT of 11% (1/9), and cranizalization alone had a recurrence of PPT of 0% (0/3). Of note, postop chronic rhinosinusitis was seen in 46% (6/13) of FESS alone, 17% (1/6) with FESS with trephination, 0% (0/9) with FESS with cranialization, and 33% (1/3) with just cranialization alone. CONCLUSIONS: Pott's Puffy tumor patients were younger and predominately male when compared to the control patients. No prior allergy diagnosis, previous trauma history, medication allergy to penicillin class or cephalosporin class, and lower body mass index are risk factors for PPT. There are 2 prognostic factors that predict recurrence of PPT: first operative treatment choice and prior sinus surgery. History of prior sinus surgery tends to increase the recurrence of PPT. The first operative treatment plan is the best shot at definitively treating PPT. Correct management surgically can prevent recurrence of PPT as well as long-term recurrence of chronic rhinosinusitis. With early diagnosis and mild disease, FESS is sufficient to prevent recurrence of PPT but chronic sinusitis may continue to occur if frontal sinus outflow track is not well opened. If considering trephination, a definitive cranialization may be more suited for more advanced disease since our study showed 50% of recurrence of PPT with trephination and FESS along with 17% chronic sinusitis long term. More advanced diseases with higher WBCs and intracranial extension do better with more aggressive surgical management with a cranialization with or without FESS which shows to reduce rates of PPT recurrence significantly.

Multi-resistant Enterobacter cloacae dacryocystitis and preseptal cellulitis: case and review of literature.

A 61-year-old man with no significant past medical history presented to a quaternary ophthalmic referral center with acute right-sided medial canthal pain, periorbital edema, and erythema despite oral antibiotic therapy. CT imaging confirmed the presence of right preseptal cellulitis and lacrimal sac aspiration identified Enterobacter cloacae. A diagnosis of acute right-sided dacryocystitis with preseptal cellulitis was made. He was successfully treated with broadening of antibiotic therapy to intravenous meropenem. Symptomatic resolution was noted on follow-up without evidence of disease recurrence. This unusual case of Enterobacter cloacae dacryocystitis and preseptal cellulitis highlights the increasing prevalence and challenges of treating these uncommon organisms.

Characterization of Impurities in Therapeutic RNAs at the Single Nucleotide Level.

The chemistry of guide RNA (gRNA) affects the performance of the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 genome editing technique. However, the literature is very scarce about the study of gRNA degradation and in particular at the single nucleotide level. In this work, we developed a workflow to characterize the impurities of large RNAs at the single nucleotide level and identified the residues prone to degradation. Our strategy involves (i) the reduction of RNA length, (ii) a chromatographic mode able to capture subtle changes in impurity polarity, and (iii) a streamlined data treatment. To illustrate the approach, stressed gRNA samples were analyzed by coupling an immobilized ribonuclease T1 cartridge to a hydrophilic interaction liquid chromatography (HILIC) column hyphenated with tandem mass spectrometry (MS/MS). Critical findings were made possible by the presented technology. In particular, the desulfurization of phosphorothioate (PS) linkages was the major degradation observed at the single nucleotide level while no change in purity profile could be observed when using conventional ion-pairing reversed-phase (IPRP) liquid chromatography. To our knowledge, this is the first time that several impurity types are screened for a large RNA molecule using an automated online digestion analysis approach.

Morbidity of salvage radical prostatectomy: limited impact of the minimally invasive approach.

PURPOSE: We aimed to report the morbidity profile of salvage radical prostatectomy (SRP) after radiotherapy failure and assess the impact of minimally invasive surgery (MIS) on postoperative complications and functional outcomes. MATERIALS AND METHODS: Between 1985 and 2019, a total of 293 patients underwent SRP; 232 underwent open SRP; and 61 underwent laparoscopic SRP with or without robotic assistance. Complications were recorded and classified into standardized categories per the Clavien-Dindo classification. RESULTS: Twenty-nine patients (10%) experienced grade 3 complications within 30 days, 22 (9.5%) after open and 7 (11%) after MIS (p = 0.6). Between 30 and 90 days after surgery, 7.3% of patients in the open group and 10% in the MIS group had grade 3 complications (p = 0.5). The most common complication was bladder neck contracture (BNC), representing 40% of the 30-90 day complications. Within one year of SRP, 81 patients (31%, 95% CI 25%, 37%) developed BNC; we saw non-significant lower rates in MIS (25 vs 32%; p = 0.4). Functional outcomes were poor after SRP and showed no difference between open and MIS groups for urinary continence (16 vs 18%, p = 0.7) and erectile function (7 vs 13%, p = 0.4). 5 year cancer-specific survival and overall survival was 95% and 88% for the entire cohort, respectively. CONCLUSIONS: Our outcomes suggest poor functional recovery after SRP, regardless of the operative approach. Currently there is no evidence favoring the use of open or MIS approach. Further studies are required to ensure comparable outcomes between these approaches.

External validation of the HIGH-2-LOW model: A predictive score for venous thromboembolism after allogeneic transplant.

In patients undergoing hematopoietic cell transplantation (HCT), venous thromboembolism (VTE) remains a serious complication that lacks validated risk assessment models (RAMs) to guide thromboprophylaxis. To address this dilemma, we performed a temporal and external validation study of the recently derived HIGH-2-LOW RAM. We selected adult patients undergoing allogeneic HCT from Fred Hutchinson Cancer Research Center (FHCRC) and MD Anderson Cancer Center (MDACC). Patients who died, received anticoagulation, or did not engraft platelets by day 30 were excluded. Primary outcomes were defined as overall VTE and pulmonary embolism ± lower-extremity deep venous thromboembolism (PE/LE-DVT) by day 180. Covariates were weighted according to the original model, except that grade 2-4 GVHD was substituted for grade 3-4. Discrimination and calibration were assessed. A total of 765 patients from FHCRC and 954 patients from MDACC were included. Incident VTE by day 180 was 5.1% at FHCRC and 6.8% at MDACC. The HIGH-2-LOW score had a c-statistic of 0.67 (0.59-0.75) for VTE and 0.75 (0.64-0.81) for PE/LE-DVT at FHCRC and 0.62 (0.55-0.70) for VTE and 0.70 (0.56-0.83) for PE/LE-DVT at MDACC. Twenty-five percent and 23% of patients were classified as high risk (2+ points) in the two cohorts, respectively. High versus low-risk was associated with odds ratio (OR) of 2.80 (1.46-5.38) for VTE and 4.21 (1.82-9.77) for PE/LE-DVT at FHCRC and OR of 3.54 (2.12-5.91) for VTE and 6.82 (2.30-20.16) for PE-LE-DVT at MDACC. The HIGH-2-LOW RAM identified allogeneic HCT recipients at high risk for VTE in both validation cohorts. It can improve evidence-based decision-making for thromboprophylaxis post-transplant.

Clinical outcomes and impact of therapeutic intervention in patients with acute myeloid leukemia who experience measurable residual disease (MRD) recurrence following MRD-negative remission.

Recurrence of MRD in AML is associated with imminent relapse unless intervened upon. Change in chemotherapy regimen and/or immediate transplant improve outcomes.

Long-term aircraft noise exposure and risk of hypertension in the Nurses' Health Studies.

BACKGROUND: Aircraft noise can affect populations living near airports. Chronic exposure to aircraft noise has been associated with cardiovascular disease, including hypertension. However, previous studies have been limited in their ability to characterize noise exposures over time and to adequately control for confounders. OBJECTIVES: The aim of this study was to examine the association between aircraft noise and incident hypertension in two cohorts of female nurses, using aircraft noise exposure estimates with high spatial resolution over a 20-year period. METHODS: We obtained contour maps of modeled aircraft noise levels over time for 90 U.S. airports and linked them with geocoded addresses of participants in the Nurses' Health Study (NHS) and Nurses' Health Study II (NHS II) to assign noise exposure for 1994-2014 and 1995-2013, respectively. We used time-varying Cox proportional hazards models to estimate hypertension risk associated with time-varying noise exposure (dichotomized at 45 and 55 dB(A)), adjusting for fixed and time-varying confounders. Results from both cohorts were pooled via random effects meta-analysis. RESULTS: In meta-analyses of parsimonious and fully-adjusted models with aircraft noise dichotomized at 45 dB(A), hazard ratios (HR) for hypertension incidence were 1.04 (95% CI: 1.00, 1.07) and 1.03 (95% CI: 0.99, 1.07), respectively. When dichotomized at 55 dB(A), HRs were 1.10 (95% CI: 1.01, 1.19) and 1.07 (95% CI: 0.98, 1.15), respectively. After conducting fully-adjusted sensitivity analyses limited to years in which particulate matter (PM) was obtained, we observed similar findings. In NHS, the PM-unadjusted HR was 1.01 (95% CI: 0.90, 1.14) and PM-adjusted HR was 1.01 (95% CI: 0.89, 1.14); in NHS II, the PM-unadjusted HR was 1.08 (95% CI: 0.96, 1.22) and the PM-adjusted HR was 1.08 (95% CI: 0.95, 1.21). Overall, in these cohorts, we found marginally suggestive evidence of a positive association between aircraft noise exposure and hypertension.

Relation between auditory difficulties and bortezomib-induced peripheral neuropathy in multiple myeloma: a single-center cross-sectional study.

PURPOSE: Bortezomib is a neurotoxic drug used in multiple myeloma and responsible for chemotherapy-induced peripheral neuropathy (CIPN). In a previous cross-sectional study, CIPN prevalence was about 26.9% in 67 patients. A second data analysis was performed to explore the relation between CIPN and auditory difficulties. METHODS: Based on 66 multiple myeloma patients from a single center, auditory difficulties were assessed with a self-questionnaire and compared to sensory CIPN (QLQ-CIPN20 questionnaire), patients' characteristics and anticancer treatments. RESULTS: The prevalence of auditory difficulties was about 42.4% (95% CI [30.6-55.2]) of the 66 patients analyzed and was higher in patients with CIPN than without (82.4% vs. 28.6%, p < 0.001). Auditory difficulties were not related to the characteristics of patients and treatments. The severity of auditory difficulties were correlated to CIPN severity (spearman's coefficient: 0.49, p = 0.009). Odds-ratio of auditory difficulties (multivariable analysis adjusted for sensory CIPN, recreation or professional noise exposure, gender, age, and treatments) was significantly associated with CIPN (18.7, 95% CI [3.0-117.1], p = 0.002). CONCLUSION: This relation between CIPN and auditory difficulties raises concerns about hearing safety in multiple myeloma patients treated by bortezomib. TRIAL REGISTRATION NUMBER: NCT03344328.

ECHS1 disease in two unrelated families of Samoan descent: Common variant - rare disorder.

Mutations in the short-chain enoyl-CoA hydratase (SCEH) gene, ECHS1, cause a rare autosomal recessive disorder of valine catabolism. Patients usually present with developmental delay, regression, dystonia, feeding difficulties, and abnormal MRI with bilateral basal ganglia involvement. We present clinical, biochemical, molecular, and functional data for four affected patients from two unrelated families of Samoan descent with identical novel compound heterozygous mutations. Family 1 has three affected boys while Family 2 has an affected daughter, all with clinical and MRI findings of Leigh syndrome and intermittent episodes of acidosis and ketosis. WES identified a single heterozygous variant in ECHS1 at position c.832G > A (p.Ala278Thr). However, western blot revealed significantly reduced ECHS1 protein for all affected family members. Decreased SCEH activity in fibroblasts and a mild increase in marker metabolites in urine further supported ECHS1 as the underlying gene defect. Additional investigations at the DNA (aCGH, WGS) and RNA (qPCR, RT-PCR, RNA-Seq, RNA-Array) level identified a silent, common variant at position c.489G > A (p.Pro163=) as the second mutation. This substitution, present at high frequency in the Samoan population, is associated with decreased levels of normally spliced mRNA. To our understanding, this is the first report of a novel, hypomorphic allele c.489G > A (p.Pro163=), associated with SCEH deficiency.

Hybrid Approach with Angiography and Limited Open Exposure to Treat Type Ia Endoleaks after Endovascular Aortic Aneurysm Repair.

BACKGROUND: Type Ia endoleaks after endovascular aortic repair (EVAR) almost always mandate secondary percutaneous reinterventions. Several patients, however, will require conversion to open surgical repair with complete graft explant, which is associated with significant morbidity and mortality. We herein present 3 cases of hybrid surgical repair for type Ia endoleaks, using a limited open exposure for proximal stent graft edge revision to achieve graft preservation and effective aneurysm sac exclusion. METHODS: Angiography was used to confirm type Ia endoleak in 3 patients (2 males) who had previous EVAR between October 2017 and October 2019. Time to the endoleak after the index EVAR was immediate in 1 patient during repair of a ruptured aneurysm, 2 months in 1 patient and 2 years in 1 patient. The aorta was exposed through a limited transabdominal (n = 1) or retroperitoneal (n = 2) approach and circumferential aortic control was achieved below the renal arteries. A row of interrupted horizontal mattress sutures of 3-0 polypropylene reinforced with Teflon pledgets was placed along the aortic neck circumference. Multi-planar angiography was then repeated to verify the absence of sac filling and successful type Ia endoleak exclusion. Follow-up abdominal duplex was obtained for all 3 patients after discharge to monitor the stent graft and confirm endoleak resolution. Furthermore, there were no instances of acute renal failure. RESULTS: In the period of review, 77 patients underwent EVAR. In the 3 patients described, we were able to achieve complete aneurysm sac exclusion and stent graft preservation in all cases. Follow-up imaging was available on 2 patients at 4-6 weeks after surgery demonstrating sustained exclusion of the endoleak. Two patients died during follow-up: one from a myocardial infarction 7 weeks after surgery and one from metastatic lung cancer at 8 months after surgery. Follow up duplex imaging at one year on the single survivor demonstrated sac shrinkage and absence of endoleak. CONCLUSIONS: Type Ia endoleaks represent a significant source of morbidity and mortality after EVAR and typically require repair to avoid aneurysm rupture. Our use of limited proximal revision without explant provides an alternative approach to resolve the endoleaks while reducing the magnitude of physiological stress when compared to an open explant. It represents a feasible option for high-risk patients.

Asymptomatic thrombosis of extrahepatic portal vein aneurysm necessitating hybrid operative repair.

BACKGROUND: Congenital portal vein aneurysm is a rare vascular anomaly with poorly understood natural history. Whereas asymptomatic aneurysms are often managed conservatively, surgery has been used in symptomatic cases complicated by thrombosis or rupture. Surgical experience in management of portal aneurysms is restricted to case studies with limited comparative data and inconsistent reporting of outcomes. A hybrid open and endovascular approach has rarely been described in the literature. METHODS: We present a case of an extrahepatic portal aneurysm which demonstrated changes on surveillance imaging concerning for early asymptomatic thrombosis. Acute thrombus was identified at the time of open aneurysm repair. We review the limited literature regarding management of portal vein aneurysms in non-cirrhotic patients. RESULTS: Our case was complicated by intrahepatic thrombo-embolism, which necessitated hybrid thrombectomy and anticoagulant therapy. The patient remains asymptomatic at three-year follow-up with no recurrent aneurysm or thrombosis on surveillance Doppler and CT imaging. CONCLUSIONS: Altered hemodynamic appearances on Doppler ultrasound and contrast-enhanced CT may warn of impending thrombosis in portal vein aneurysms. Hybrid open and endovascular surgical repair ensures vessel patency and a durable surgical result.

Student Teamwork During COVID-19: Challenges, Changes, and Consequences.

The COVID-19 pandemic has greatly affected all of society, including teams in organizational settings. Collaborative teamwork is particularly susceptible to pandemic disruptions, as coordination across individuals becomes challenging in socially distanced and virtual contexts. Unfortunately, COVID-19 research thus far has primarily studied individual health and performance. Analysis of 90 open-ended survey responses gives voice to students working in project teams during the pandemic and provides future research directions regarding the multilevel impacts of the pandemic on teamwork. Results reflect three themes: (1) challenges experienced; (2) changes to team communication, tasks, and roles; and (3) consequences to team progress and outcomes.

YejM Controls LpxC Levels by Regulating Protease Activity of the FtsH/YciM Complex of Escherichia coli.

LpxC is a deacetylase that catalyzes the first committed step of lipid A biosynthesis in Escherichia coli LpxC competes for a common precursor, R-3-hydroxymyristoyl-UDP-GlcNAc, with FabZ, whose dehydratase activity catalyzes the first committed step of phospholipid biosynthesis. To maintain the optimum flow of the common precursor to these two competing pathways, the LpxC level is controlled by FtsH/YciM-mediated proteolysis. It is not known whether this complex or another protein senses the status of lipid A synthesis to control LpxC proteolysis. The work carried out in this study began with a novel mutation, yejM1163, which causes hypersensitivity to large antibiotics such as vancomycin and erythromycin. Isolates resistant to these antibiotics carried suppressor mutations in the ftsH and yciM genes. Western blot analysis showed a dramatically reduced LpxC level in the yejM1163 background, while the presence of ftsH or yciM suppressor mutations restored LpxC levels to different degrees. Based on these observations, it is proposed that YejM is a sensor of lipid A synthesis and controls LpxC levels by modulating the activity of the FtsH/YciM complex. The truncation of the periplasmic domain in the YejM1163 protein causes unregulated proteolysis of LpxC, thus diverting a greater pool of R-3-hydroxymyristoyl-UDP-GlcNAc toward phospholipid synthesis. This imbalance in lipid synthesis perturbs the outer membrane permeability barrier, causing hypersensitivity toward vancomycin and erythromycin. yejM1163 suppressor mutations in ftsH and yciM lower the proteolytic activity toward LpxC, thus restoring lipid homeostasis and the outer membrane permeability barrier.IMPORTANCE Lipid homeostasis is critical for proper envelope functions. The level of LpxC, which catalyzes the first committed step of lipopolysaccharide (LPS) synthesis, is controlled by an essential protease complex comprised of FtsH and YciM. Work carried out here suggests YejM, an essential envelope protein, plays a central role in sensing the state of LPS synthesis and controls LpxC levels by regulating the activity of FtsH/YciM. All four essential proteins are attractive targets of therapeutic development.