Neural circuit mechanisms underlying aberrantly prolonged functional hyperemia in young Alzheimer's disease mice.

Neurovascular defects are one of the most common alterations in Alzheimer's disease (AD) pathogenesis, but whether these deficits develop before the onset of amyloid beta (Aß) accumulation remains to be determined. Using in vivo optical imaging in freely moving mice, we explored activity-induced hippocampal microvascular blood flow dynamics in AppSAA knock-in and J20 mouse models of AD at early stages of disease progression. We found that prior to the onset of Aß accumulation, there was a pathologically elevated blood flow response to context exploration, termed functional hyperemia. After the onset of Aß accumulation, this context exploration-induced hyperemia declined rapidly relative to that in control mice. Using in vivo electrophysiology recordings to explore the neural circuit mechanism underlying this blood flow alteration, we found that hippocampal interneurons before the onset of Aß accumulation were hyperactive during context exploration. Chemogenetic tests suggest that hyperactive activation of inhibitory neurons accounted for the elevated functional hyperemia. The suppression of nitric oxide (NO) produced from hippocampal interneurons in young AD mice decreased the accumulation of Aß. Together, these findings reveal that neurovascular coupling is aberrantly elevated before Aß deposition, and this hyperactive functional hyperemia declines rapidly upon Aß accumulation.

Targeting acetyl-CoA metabolism attenuates the formation of fear memories through reduced activity-dependent histone acetylation.

Histone acetylation is a key component in the consolidation of long-term fear memories. Histone acetylation is fueled by acetyl-coenzyme A (acetyl-CoA), and recently, nuclear-localized metabolic enzymes that produce this metabolite have emerged as direct and local regulators of chromatin. In particular, acetyl-CoA synthetase 2 (ACSS2) mediates histone acetylation in the mouse hippocampus. However, whether ACSS2 regulates long-term fear memory remains to be determined. Here, we show that Acss2 knockout is well tolerated in mice, yet the Acss2-null mouse exhibits reduced acquisition of long-term fear memory. Loss of Acss2 leads to reductions in both histone acetylation and expression of critical learning and memory-related genes in the dorsal hippocampus, specifically following fear conditioning. Furthermore, systemic administration of blood-brain barrier-permeable Acss2 inhibitors during the consolidation window reduces fear-memory formation in mice and rats and reduces anxiety in a predator-scent stress paradigm. Our findings suggest that nuclear acetyl-CoA metabolism via ACSS2 plays a critical, previously unappreciated, role in the formation of fear memories.

Not all types of depressed patients who persist with their antidepressant treatment improve in side effect complaints: A comparison of treatment completers and dropouts in the STAR*D trial.

INTRODUCTION: There is a "traditional belief" that antidepressant side effect complaints improve with medication persistence; however, support for this theory has remained inconclusive. We aimed to examine if side effect complaints improved over time by modeling the relationship between side effect complaints and time at dropout for patients receiving citalopram during the first level of acute treatment in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial. METHODS: We categorized the 2833 patients into five patterns by week of dropout. We used pattern-mixture modeling to model change in side effect complaints (frequency, intensity, and burden) over the 12-week course of treatment, while accounting for attrition and depressive severity. Using post-hoc linear contrasts, we compared the attrition patterns with the completers' pattern for severity of side effect complaints at each respective last visit prior to dropout as well as averaged side effect complaints across the duration of treatment. We also reported frequencies and tolerability of side effects for nine organ/function systems over the course of treatment. RESULTS: Patients who dropped out early exhibited worsening side effect burden and patients who dropped out later showed improvements in side effect frequency and intensity. Treatment completers improved in all side effect complaints over the course of treatment. Early attrition patterns had more severe side effect complaints for both tests of post-hoc linear contrasts than later attrition patterns and completers. CONCLUSIONS: Side effect complaints from antidepressant treatment improve over time, but only for some types of patients. As a precaution for early dropout, clinicians should monitor patients who exhibit worsening and more severe side effect complaints-especially in the first 6 weeks of antidepressant treatment. In addition, clinicians may want to consider changing the type of treatment early on for these patients, rather than encouraging them to persist with their current medication.

Finding MeVO: Identifying Intracranial Medium-Vessel Occlusions at CT Angiography.

The development of methods to detect and treat intracranial large-vessel occlusions (LVOs) has revolutionized the management of acute ischemic stroke. CT angiography (CTA) of the head and neck is effective in depicting LVOs and widely used in the evaluation of patients who have had a stroke. Ongoing efforts are now focused on the potential to detect and treat intracranial medium-vessel occlusions (MeVOs), which by definition are smaller than LVOs and thus more difficult to detect with CTA. The authors review common and variant anatomies of medium-sized cerebral arteries and the appearance of a variety of MeVOs on CT angiograms. Possible pitfalls in MeVO detection include rare anatomic variants, calcified thrombi, and stump occlusions. Current recommendations for performing CTA and ancillary methods that might aid in MeVO detection are discussed. Understanding the relevant anatomy and the variety of appearances of MeVOs aids radiologists in identifying these occlusions, particularly in the setting of urgent stroke. ©RSNA, 2024 See the invited commentary by Ospel and Nguyen in this issue.

Effectiveness and safety of monoamine oxidase inhibitor treatment for bipolar depression versus unipolar depression: An exploratory case cohort study.

OBJECTIVE: Patients with bipolar disorder spend most of their clinical lifetime in the depressive phase of their illness. However, antidepressants are discouraged in the treatment of bipolar depression due to concerns over manic induction and drug ineffectiveness. Some reports suggest that monoamine oxidase inhibitors (MAOIs) may be safe and effective compared to other antidepressants in treating bipolar depression. The present study compared the safety and effectiveness of MAOI therapy in patients with bipolar versus unipolar depression. METHODS: Data were collected from approximately 2500 clinical research charts of patients treated with MAOI therapy at a university mood disorder clinic between 1983 and 2015. A mixed-effects model was created with patient entered as the random effect. The model included the primary diagnosis (i.e., either unipolar or bipolar depression) and other clinical covariates as fixed-effect predictors. RESULTS: Patients with bipolar depression demonstrated lower post-treatment clinical global impressions/severity scores versus patients with unipolar depression (p = 0.04). Neither group demonstrated a full syndromal manic or hypomanic episode. A higher proportion of patients with bipolar depression reported myoclonic tics and tremors, which may have resulted from concomitant lithium use. Amongst the covariates, only the number of prior antidepressant trials predicted poorer outcomes from MAOI therapy. CONCLUSION: MAOIs may be more effective-and as safe-for patients with bipolar depression versus unipolar depression. Future studies should explore this possible advantage using a larger sample size.

Development of a Telemedicine Screening Program During the COVID-19 Pandemic.

Background: Telemedicine use increased during the COVID-19 pandemic due to concerns for patient and provider safety. Given the lack of testing resources initially and the large geographical range served by Augusta University (AU), a telemedicine platform with up-to-date screening guidelines was implemented for COVID-19 testing in March 2020. Our objective was to understand the level of adherence to telemedicine screening guidelines for COVID-19. Methods: The study population included health care providers and population who participated in an encounter in the AU Health Express Care virtual care program from March 22 to May 21, 2020. All encounters were intended to be for COVID-19 screening, free, and available 24 h per day, 7 days per week. Screening guidelines were developed by AU based on information from the Centers for Disease Control and Prevention and the Georgia Department of Public Health. Results: Among 17,801 total encounters, 13,600 were included in the final analysis. Overall adherence to screening guidelines was 71% in the adult population and 57% in the pediatric population. When providers did not follow guidelines, 72% determined that the patient should have a positive screen. Guidelines themselves determined that only 52% of encounters should have a positive screen. Providers' specialty significantly correlated with guideline adherence (p = 0.002). Departments with the highest adherence were psychiatry, neurology, and ophthalmology. No significant correlation was found between guideline adherence and provider degree/position. Conclusions: This study provides proof of concept of a free telehealth screening platform during an ongoing pandemic. Our screening experience was effective and different specialties participated. Our patient population lived in lower than average income zip codes, suggesting that our free telemedicine screening program successfully reached populations with higher financial barriers to health care. Early training and a posteriori knowledge of telemedicine was likely key to screening guideline adherence.

Patients' judgments of the importance of treatment-induced reductions in symptoms of depression: The role of specific symptoms, magnitudes of change, and post-treatment levels.

Objective: An implicit assumption in the use of depressive severity measures to assess change during treatment, such as the Hamilton Rating Scale for Depression (HRSD), is that reductions from pre- to post-treatment that are equal to each other are of equal value. However, stakeholders' valuations of changes might depart substantially from this assumption. Method: Vignettes were constructed that reflected the six possible 1, 2, and 3-point reductions on five cognitive and four somatic symptoms derived from the HRSD. Former or currently depressed patients provided judgments of the importance of the symptom reductions. Mean importance ratings were modeled using symptom category and the pre/post-treatment combination. Differences were explored using the Tukey method. Results: Results indicated that mean ratings, from most to least important, were: Anxiety, Suicide, Depressed Mood, Work, and Guilt (the cognitive symptoms) followed by Somatic, Sleep, Appetite & Weight, and Retardation (the somatic symptoms). Participants valued reductions that resulted in posttreatment scores of zero more than expected, given the magnitude of the reductions. Conclusions: The value of reductions in symptoms captured by the HRSD, as judged by patients, appears to differ as a function of symptom category and the post-treatment score. Similar patterns might characterize other measures of depression severity.

Treatment selection in borderline personality disorder between dialectical behavior therapy and psychodynamic psychiatric management.

BACKGROUND: No evidence-based therapy for borderline personality disorder (BPD) exhibits a clear superiority. However, BPD is highly heterogeneous, and different patients may specifically benefit from the interventions of a particular treatment. METHODS: From a randomized trial comparing a year of dialectical behavior therapy (DBT) to general psychiatric management (GPM) for BPD, long-term (2-year-post) outcome data and patient baseline variables (n = 156) were used to examine individual and combined patient-level moderators of differential treatment response. A two-step bootstrapped and partially cross-validated moderator identification process was employed for 20 baseline variables. For identified moderators, 10-fold bootstrapped cross-validated models estimated response to each therapy, and long-term outcomes were compared for patients randomized to their model-predicted optimal v. non-optimal treatment. RESULTS: Significant moderators surviving the two-step process included psychiatric symptom severity, BPD impulsivity symptoms (both GPM > DBT), dependent personality traits, childhood emotional abuse, and social adjustment (all DBT > GPM). Patients randomized to their model-predicted optimal treatment had significantly better long-term outcomes (d = 0.36, p = 0.028), especially if the model had a relatively stronger (top 60%) prediction for that patient (d = 0.61, p = 0.004). Among patients with a stronger prediction, this advantage held even when applying a conservative statistical check (d = 0.46, p = 0.043). CONCLUSIONS: Patient characteristics influence the degree to which they respond to two treatments for BPD. Combining information from multiple moderators may help inform providers and patients as to which treatment is the most likely to lead to long-term symptom relief. Further research on personalized medicine in BPD is needed.

A demonstration of a multi-method variable selection approach for treatment selection: Recommending cognitive-behavioral versus psychodynamic therapy for mild to moderate adult depression.

Objective: We use a new variable selection procedure for treatment selection which generates treatment recommendations based on pre-treatment characteristics for adults with mild-to-moderate depression deciding between cognitive behavioral (CBT) versus psychodynamic therapy (PDT). Method: Data are drawn from a randomized comparison of CBT versus PDT for depression (N = 167, 71% female, mean-age = 39.6). The approach combines four different statistical techniques to identify patient characteristics associated consistently with differential treatment response. Variables are combined to generate predictions indicating each individual's optimal-treatment. The average outcomes for patients who received their indicated treatment versus those who did not were compared retrospectively to estimate model utility. Results: Of 49 predictors examined, depression severity, anxiety sensitivity, extraversion, and psychological treatment-needs were included in the final model. The average post-treatment Hamilton-Depression-Rating-Scale score was 1.6 points lower (95%CI = [0.5:2.8]; d = 0.21) for those who received their indicated-treatment compared to non-indicated. Among the 60% of patients with the strongest treatment recommendations, that advantage grew to 2.6 (95%CI = [1.4:3.7]; d = 0.37). Conclusions: Variable selection procedures differ in their characterization of the importance of predictive variables. Attending to consistently-indicated predictors may be sensible when constructing treatment selection models. The small N and lack of separate validation sample indicate a need for prospective tests before this model is used.

Definitive single fraction stereotactic ablative radiotherapy for inoperable early-stage breast cancer: A case report.

We review a case of inoperable early stage breast cancer treated definitively with the use of stereotactic ablative radiotherapy (SABR). A 57-year-old female with a history of decompensated cirrhosis with early stage breast cancer was treated with 25 Gy in one fraction. At her 7-month follow up visit, there was a complete resolution of disease on imaging. This case represents a novel approach for the treatment of breast cancer with SABR when surgery is contraindicated.

How Do You Measure Up: Quality Measurement for Improving Patient Care and Establishing the Value of Infectious Diseases Specialists.

The shift from volume-based to value-based reimbursement has created a need for quantifying clinical performance of infectious diseases (ID) physicians. Nationally recognized ID specialty-specific quality measures will allow stakeholders, such as patients and payers, to determine the value of care provided by ID physicians and will promote clinical quality improvement. Few ID-specific measures have been developed; herein, we provide an overview of the importance of quality measurement for ID, discuss issues in quality measurement specific to ID, and describe standards by which candidate quality measures can be evaluated. If ID specialists recognize the need for quality measurement, then ID specialists can direct ID-related quality improvement, quantify the impact of ID physicians on patient outcomes, compare their performance to that of peers, and convey to stakeholders the value of the specialty.

Prior Antidepressant Treatment Trials May Predict a Greater Risk of Depressive Relapse During Antidepressant Maintenance Therapy.

BACKGROUND: We examined the influence of prior antidepressant treatment trials on the likelihood of depressive relapse, and time to depressive relapse, during maintenance therapy of bipolar II disorder in treatment-responsive subjects who had recovered from a major depressive episode. METHODS: Data were derived from a prospective, randomized, double-blind trial of 148 adult subjects with bipolar II major depressive episode who were initially administered open-label fluoxetine monotherapy for 12 weeks. Remitters with a final Hamilton Rating Scale for Depression score of 8 or lower were then randomized to continuation therapy with either fluoxetine (n = 28), lithium (n = 26), or placebo (n = 27) for 50 additional weeks. RESULTS: An increase in the number of prior antidepressant treatment trials was significantly associated with a greater likelihood of depressive relapse for all treatment conditions taken together [odds ratio (OR) = 1.42, z = 2.49, P = 0.01] and for the 2 active treatment conditions together (OR = 1.51, z = 2.28, P = 0.02). An increase in the number of prior antidepressant trials was also associated with a trend-level shortening in the time to relapse for all treatment conditions taken together (hazard ratio = 1.15; confidence interval, 0.99-1.35; P = 0.07) and a significantly shorter time to relapse for subjects in the 2 active treatment conditions (hazard ratio = 1.30; confidence interval, 1.05-1.62; P = 0.02). CONCLUSIONS: These findings support prior evidence of a negative influence of the number of prior antidepressant treatment trials on the likelihood of response and suggest that the number of prior antidepressant trials may also be associated with a greater odds of depressive relapse, and a shorter time to relapse, during antidepressant maintenance therapy in recovered depressed subjects with bipolar II disorder.

Relative Effectiveness of Monoamine Oxidase Inhibitor and Tricyclic Antidepressant Combination Therapy for Treatment-Resistant Depression.

PURPOSE/BACKGROUND: We examined the relative safety and effectiveness of adding a monoamine oxidase inhibitor (MAOI) to a failed tricyclic antidepressant (TCA) trial versus adding a TCA to a failed MAOI trial or adding a TCA to a failed TCA trial in treatment-resistant depression. METHODS/PROCEDURES: Data were retrospectively harvested from approximately 2500 treatment charts of subjects with treatment-resistant depression who attended a university mood disorders clinic between 1983 and 2015. Hierarchical linear modeling was used to examine the effectiveness of treatment condition on outcome. Relative adverse event profiles were also examined. FINDINGS/RESULTS: Eighty-four treatment outcome observations were made from 54 subjects who received combination therapy: TCA plus TCA (n = 22), TCA plus MAOI (n = 44), and MAOI plus TCA (n = 18). Treatment condition predicted a poorer (albeit not statistically significant) outcome for TCA plus TCA compared with TCA plus MAOI, or MAOI plus TCA therapy (P = 0.098). Specific adverse events occurred with significantly greater frequency between treatment groups; that is, impotence was more frequent with TCA plus MAOI therapy; headaches and insomnia were more frequent with MAOI plus TCA therapy; and constipation was more frequent with TCA plus TCA therapy. There were no reported or observed hypertensive or serotonergic events. IMPLICATIONS/CONCLUSIONS: In contrast to conventional wisdom that combined TCA and MAOI therapy should be avoided, the judicious use of this combination may be relatively safe and effective compared with combined TCA plus TCA therapy. However, sample sizes were limited, and the analysis was nonrandomized and retrospective.

Predictive modeling for response to lithium and quetiapine in bipolar disorder.

OBJECTIVES: Lithium and quetiapine are known to be effective treatments for bipolar disorder. However, little information is available to inform prediction of response to these medications. Machine-learning methods can identify predictors of response by examining variables simultaneously. Further evaluation of models on a test sample can estimate how well these models would generalize to other samples. METHODS: Data (N = 482) were drawn from a randomized clinical trial of outpatients with bipolar I or II disorder who received adjunctive personalized treatment plus either lithium or quetiapine. Elastic net regularization (ENR) was used to generate models for lithium and quetiapine; these models were evaluated on a test set. RESULTS: Predictions from the lithium model explained 17.4% of the variance in actual observed scores of patients who received lithium in the test set, while predictions from the quetiapine model explained 32.1% of the variance of patients that received quetiapine. Of the baseline variables selected, those with the largest parameter estimates were: severity of mania; attention-deficit/hyperactivity disorder (ADHD) comorbidity; nonsuicidal self-injurious behavior; employment; and comorbidity with each of two anxiety disorders (social phobia/society anxiety and agoraphobia). Predictive accuracy of the ENR model outperformed the simple and basic theoretical models. CONCLUSION: ENR is an effective approach for building optimal and generalizable models. Variables identified through this methodology can inform future research on predictors of response to lithium and quetiapine, as well as future modeling efforts of treatment choice in bipolar disorder.

Emergency Medical Services and Remote Medical Oversight in Sequoia and Kings Canyon National Parks, 2011-2013.

INTRODUCTION: The University of California San Francisco Fresno Department of Emergency Medicine provides base hospital support for the Sequoia and Kings Canyon National Parks (SEKI) emergency medical services (EMS) system. This descriptive epidemiologic study reports reasons the park EMS system is used and interventions provided, detailing the nature of patient encounters, type and frequency of injuries and interventions, reasons for base hospital contact, and patient dispositions. METHODS: Patient charts for all EMS encounters in SEKI from 2011 to 2013 were included, and relevant data were extracted by a single reviewer. RESULTS: Of the 704 charts reviewed, 570 (81%) were frontcountry patient encounters (within 1.6 km [1 mi] of a paved road); 100 (14%) were backcountry; and 34 (5%) occurred in undefined locations. Regarding sex and age, 58% of patients were men; 22% were younger than 18 y, and 15% were 65 y or older. More than 80% of calls occurred during the months of June through August. The most common complaints were extremity trauma (24%), torso trauma (13%), and lacerations (9%). Almost 50% of patients were transferred to a higher level of care. Medications were administered to 37% of patients, with oxygen being the most common. Procedures were performed 49% of the time, primarily intravenous access and splinting. Base hospital contact was made 38% of the time, most commonly (54%) for advice regarding disposition. CONCLUSIONS: SEKI EMS providers encounter a wide variety of patients in various settings, including the backcountry. Resource allocation, training, and protocol development should be tailored to meet their needs.

Sepsis National Hospital Inpatient Quality Measure (SEP-1): Multistakeholder Work Group Recommendations for Appropriate Antibiotics for the Treatment of Sepsis.

The Center for Medicare and Medicaid Services adopted the Early Management Bundle, Severe Sepsis/Septic Shock (SEP-1) performance measure to the Hospital Inpatient Quality Reporting Program in July 2015 to help address the high mortality and high cost associated with sepsis. The SEP-1 performance measure requires, among other critical interventions, timely administration of antibiotics to patients with sepsis or septic shock. The multistakeholder workgroup recognizes the need for SEP-1 but strongly believes that multiple antibiotics listed in the antibiotic tables for SEP-1 are not appropriate and the use of these antibiotics, as called for in the SEP-1 measure, is not in alignment with prudent antimicrobial stewardship. To promote the appropriate use of antimicrobials and combat antimicrobial resistance, the workgroup provides recommendations for appropriate antibiotics for the treatment of sepsis.

Stereotactic radiosurgery for brain metastases from primary head and neck carcinomas: a retrospective analysis.

Patients with head and neck malignancies commonly develop metastatic disease, yet rarely do these carcinomas metastasize to the brain. Stereotactic radiosurgery (SRS) is routinely employed to treat brain metastases (BM). This study was undertaken to examine the efficacy of SRS for BM from primary head and neck carcinomas. From 2000 to 2016, a total of 19 patients with 38 lesions were retrospectively identified. All patients presented with a primary head and neck malignancy and subsequently developed metastatic disease to the brain treated with SRS at our institution. Actuarial rates for overall survival (OS), local control (LC) and distant brain metastases (DBM) were calculated using Kaplan-Meier estimates. Median follow up was 6.8 months and median survival was 15.8 months. Eleven lesions received post-operative SRS to a surgical cavity and 27 lesions received definitive SRS to a metastasis. The median dose prescribed was 18 Gy. One-year actuarial rate for LC was 77.3% (95% confidence interval [CI] 44-92%) while 1 year and 2 year rates of OS were 52.9% (CI 28-73%) and 31.7% (CI 11-55%) respectively. The median time to develop DBM was 8.4 months. Three patients (16%) underwent repeat SRS following development of new BM and three patients (16%) underwent salvage whole brain radiotherapy (WBRT). SRS may be utilized in the treatment of patients with primary head and neck malignancies metastasized to the brain with high efficacy. Patients with well-controlled systemic disease and good performance status may benefit the most from definitive SRS while avoiding WBRT.

Inhibition of epithelial-to-mesenchymal transition and pulmonary fibrosis by methacycline.

A high-throughput small-molecule screen was conducted to identify inhibitors of epithelial-mesenchymal transition (EMT) that could be used as tool compounds to test the importance of EMT signaling in vivo during fibrogenesis. Transforming growth factor (TGF)-ß1-induced fibronectin expression and E-cadherin repression in A549 cells were used as 48-hour endpoints in a cell-based imaging screen. Compounds that directly blocked Smad2/3 phosphorylation were excluded. From 2,100 bioactive compounds, methacycline was identified as an inhibitor of A549 EMT with the half maximal inhibitory concentration (IC50) of roughly 5 µM. In vitro, methacycline inhibited TGF-ß1-induced α-smooth muscle actin, Snail1, and collagen I of primary alveolar epithelial cells . Methacycline inhibited TGF-ß1-induced non-Smad pathways, including c-Jun N-terminal kinase, p38, and Akt activation, but not Smad or ß-catenin transcriptional activity. Methacycline had no effect on baseline c-Jun N-terminal kinase, p38, or Akt activities or lung fibroblast responses to TGF-ß1. In vivo, 100 mg/kg intraperitoneal methacycline delivered daily beginning 10 days after intratracheal bleomycin improved survival at Day 17 (P < 0.01). Bleomycin-induced canonical EMT markers, Snail1, Twist1, collagen I, as well as fibronectin protein and mRNA, were attenuated by methacycline (Day 17). Methacycline did not attenuate inflammatory cell accumulation or alter TGF-ß1-responsive genes in alveolar macrophages. These studies identify a novel inhibitor of EMT as a potent suppressor of fibrogenesis, further supporting the concept that EMT signaling is important to lung fibrosis. The findings also provide support for testing the impact of methacycline or doxycycline, an active analog, on progression of human pulmonary fibrosis.

A lexicon of assessment and outcome measures for telemental health.

BACKGROUND: The purpose of this document is to provide initial recommendations to telemental health (TMH) professionals for the selection of assessment and outcome measures that best reflect the impacts of mental health treatments delivered via live interactive videoconferencing. MATERIALS AND METHODS: The guidance provided here was created through an expert consensus process and is in the form of a lexicon focused on identified key TMH outcomes. RESULTS: Each lexical item is elucidated by a definition, recommendations for assessment/measurement, and additional commentary on important considerations. The lexicon is not intended as a current literature review of the field, but rather as a resource to foster increased dialogue, critical analysis, and the development of the science of TMH assessment and evaluation. The intent of this lexicon is to better unify the TMH field by providing a resource to researchers, program managers, funders, regulators and others for assessing outcomes. CONCLUSIONS: This document provides overall context for the key aspects of the lexicon.

Identification, characterization, and immobilization of an organic solvent-stable alkaline hydrolase (PA27) from Pseudomonas aeruginosa MH38.

An organic solvent-stable alkaline hydrolase (PA27) from Pseudomonas aeruginosa MH38 was expressed, characterized, and immobilized for biotechnological applications. Recombinant PA27 was expressed in Escherichia coli as a 27 kDa soluble protein and was purified by standard procedures. PA27 was found to be stable at pH 8-11 and below 50 °C. It maintained more than 80% of its activity under alkaline conditions (pH 8.0-11.0). Furthermore, PA27 exhibited remarkable stability in benzene and n-hexane at concentrations of 30% and 50%. Based on these properties, immobilization of PA27 for biotechnological applications was explored. Scanning electron microscopy revealed a very smooth spherical structure with numerous large pores. Interestingly, immobilized PA27 displayed improved thermal/chemical stabilities and high reusability. Specifically, immobilized PA27 has improved thermal stability, maintaining over 90% of initial activity after 1 h of incubation at 80 °C, whereas free PA27 had only 35% residual activity. Furthermore, immobilized PA27 showed higher residual activity than the free enzyme biocatalysts against detergents, urea, and phenol. Immobilized PA27 could be recycled 20 times with retention of ~60% of its initial activity. Furthermore, macroscopic hydrogel formation of PA27 was also investigated. These characteristics make PA27 a great candidate for an industrial biocatalyst with potential applications.