Ectopic Expression of Neurod1 Is Sufficient for Functional Recovery following a Sensory-Motor Cortical Stroke.

Stroke is the leading cause of adult disability worldwide. The majority of stroke survivors are left with devastating functional impairments for which few treatment options exist. Recently, a number of studies have used ectopic expression of transcription factors that direct neuronal cell fate with the intention of converting astrocytes to neurons in various models of brain injury and disease. While there have been reports that question whether astrocyte-to-neuron conversion occurs in vivo, here, we have asked if ectopic expression of the transcription factor Neurod1 is sufficient to promote improved functional outcomes when delivered in the subacute phase following endothelin-1-induced sensory-motor cortex stroke. We used an adeno-associated virus to deliver Neurod1 from the short GFAP promoter and demonstrated improved functional outcomes as early as 28 days post-stroke and persisting to at least 63 days post-stroke. Using Cre-based cell fate tracking, we showed that functional recovery correlated with the expression of neuronal markers in transduced cells by 28 days post-stroke. By 63 days post-stroke, the reporter-expressing cells comprised ~20% of all the neurons in the perilesional cortex and expressed markers of cortical neuron subtypes. Overall, our findings indicate that ectopic expression of Neurod1 in the stroke-injured brain is sufficient to enhance neural repair.

CyVerse: Cyberinfrastructure for open science.

CyVerse, the largest publicly-funded open-source research cyberinfrastructure for life sciences, has played a crucial role in advancing data-driven research since the 2010s. As the technology landscape evolved with the emergence of cloud computing platforms, machine learning and artificial intelligence (AI) applications, CyVerse has enabled access by providing interfaces, Software as a Service (SaaS), and cloud-native Infrastructure as Code (IaC) to leverage new technologies. CyVerse services enable researchers to integrate institutional and private computational resources, custom software, perform analyses, and publish data in accordance with open science principles. Over the past 13 years, CyVerse has registered more than 124,000 verified accounts from 160 countries and was used for over 1,600 peer-reviewed publications. Since 2011, 45,000 students and researchers have been trained to use CyVerse. The platform has been replicated and deployed in three countries outside the US, with additional private deployments on commercial clouds for US government agencies and multinational corporations. In this manuscript, we present a strategic blueprint for creating and managing SaaS cyberinfrastructure and IaC as free and open-source software.

Human atlastin-3 is a constitutive ER membrane fusion catalyst.

Homotypic membrane fusion catalyzed by the atlastin (ATL) GTPase sustains the branched endoplasmic reticulum (ER) network in metazoans. Our recent discovery that two of the three human ATL paralogs (ATL1/2) are C-terminally autoinhibited implied that relief of autoinhibition would be integral to the ATL fusion mechanism. An alternative hypothesis is that the third paralog ATL3 promotes constitutive ER fusion with relief of ATL1/2 autoinhibition used conditionally. However, published studies suggest ATL3 is a weak fusogen at best. Contrary to expectations, we demonstrate here that purified human ATL3 catalyzes efficient membrane fusion in vitro and is sufficient to sustain the ER network in triple knockout cells. Strikingly, ATL3 lacks any detectable C-terminal autoinhibition, like the invertebrate Drosophila ATL ortholog. Phylogenetic analysis of ATL C-termini indicates that C-terminal autoinhibition is a recent evolutionary innovation. We suggest that ATL3 is a constitutive ER fusion catalyst and that ATL1/2 autoinhibition likely evolved in vertebrates as a means of upregulating ER fusion activity on demand.

Membrane fusion by Drosophila atlastin does not require GTP hydrolysis.

Atlastin (ATL) GTPases undergo trans dimerization and a power strokelike crossover conformational rearrangement to drive endoplasmic reticulum membrane fusion. Fusion depends on GTP, but the role of nucleotide hydrolysis has remained controversial. For instance, nonhydrolyzable GTP analogs block fusion altogether, suggesting a requirement for GTP hydrolysis in ATL dimerization and crossover, but this leaves unanswered the question of how the ATL dimer is disassembled after fusion. We recently used the truncated cytoplasmic domain of wild-type Drosophila ATL (DATL) and a novel hydrolysis-deficient D127N variant in single turnover assays to reveal that dimerization and crossover consistently precede GTP hydrolysis, with hydrolysis coinciding more closely with dimer disassembly. Moreover, while nonhydrolyzable analogs can bind the DATL G domain, they fail to fully recapitulate the GTP-bound state. This predicted that nucleotide hydrolysis would be dispensable for fusion. Here we report that the D127N variant of full-length DATL drives both outer and inner leaflet membrane fusion with little to no detectable hydrolysis of GTP. However, the trans dimer fails to disassemble and subsequent rounds of fusion fail to occur. Our findings confirm that ATL mediated fusion is driven in the GTP-bound state, with nucleotide hydrolysis serving to reset the fusion machinery for recycling.

Reconstitution of human atlastin fusion activity reveals autoinhibition by the C terminus.

ER network formation depends on membrane fusion by the atlastin (ATL) GTPase. In humans, three paralogs are differentially expressed with divergent N- and C-terminal extensions, but their respective roles remain unknown. This is partly because, unlike Drosophila ATL, the fusion activity of human ATLs has not been reconstituted. Here, we report successful reconstitution of fusion activity by the human ATLs. Unexpectedly, the major splice isoforms of ATL1 and ATL2 are each autoinhibited, albeit to differing degrees. For the more strongly inhibited ATL2, autoinhibition mapped to a C-terminal α-helix is predicted to be continuous with an amphipathic helix required for fusion. Charge reversal of residues in the inhibitory domain strongly activated its fusion activity, and overexpression of this disinhibited version caused ER collapse. Neurons express an ATL2 splice isoform whose sequence differs in the inhibitory domain, and this form showed full fusion activity. These findings reveal autoinhibition and alternate splicing as regulators of atlastin-mediated ER fusion.

Awareness, social cognition, and commitment: Developing a social justice orientation in psychology training programs.

This study investigates how the awareness of social inequities and racism may serve as a foundation for psychology trainees' social justice self-efficacy beliefs, outcome expectations, interests, and commitment. Using the social-cognitive justice developmental framework proposed by Miller et al. (2009), a total of 222 participants were recruited from accredited applied psychology programs across the United States. Participants completed measures assessing their levels of two dimensions of critical consciousness: Egalitarianism and awareness of inequality (Diemer et al., 2017), their colorblind racial attitudes (Neville et al., 2000), and their social justice self-efficacy, outcome expectations, interests, and commitment (Miller et al., 2009). A hypothesized path model was fit to the data. Alternative models were also considered. Results indicated that participants who endorsed egalitarianism and were more aware of social inequities showed greater awareness of racism and, in turn, were more likely to endorse a higher orientation and commitment to social justice. Limitations and implications for future research and training are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Informatics response to address the COVID-19 pandemic in a safety net healthcare system.

In service of particularly vulnerable populations, safety net healthcare systems must nimbly leverage health information technology (IT), including electronic health records (EHRs), to coordinate the medical and public health response to the novel coronavirus (COVID-19). Six months after the San Francisco Department of Public Health implemented a new EHR across its hospitals and citywide clinics, California declared a state of emergency in response to COVID-19. This paper describes how the IT and informatics teams supported San Francisco Department of Public Health's goals of expanding the safety net healthcare system capacity, meeting the needs of specific vulnerable populations, increasing equity in COVID-19 testing access, and expanding public health analytics and research capacity. Key enabling factors included critical partnerships with operational leaders, early identification of priorities, a clear governance structure, agility in the face of rapidly changing circumstances, and a commitment to vulnerable populations.

Systematic review on outcome of free functioning muscle transfers for elbow flexion in brachial plexus injuries.

Elbow flexion is widely regarded as the most important function to restore in brachial plexus injuries. Free functioning muscle transfer surgery is indicated in patients with delayed presentation or failure of other primary procedures. Results of the transfer surgeries have been reported in the form of case series, but no further studies are available. This systematic review aims to provide a deeper understanding of this complex surgery and consists of 19 articles that include 364 patients. Data on injury characteristics, surgical techniques, complications as well as outcome measures were analysed. Our results show that functional muscle transfer for elbow flexion enables 87% and 65% of patients to achieve a useful power grade of ≥ 3 and ≥ 4, respectively, although other important outcome factors should be considered.

GTP hydrolysis promotes disassembly of the atlastin crossover dimer during ER fusion.

Membrane fusion of the ER is catalyzed when atlastin GTPases anchored in opposing membranes dimerize and undergo a crossed over conformational rearrangement that draws the bilayers together. Previous studies have suggested that GTP hydrolysis triggers crossover dimerization, thus directly driving fusion. In this study, we make the surprising observations that WT atlastin undergoes crossover dimerization before hydrolyzing GTP and that nucleotide hydrolysis and Pi release coincide more closely with dimer disassembly. These findings suggest that GTP binding, rather than its hydrolysis, triggers crossover dimerization for fusion. In support, a new hydrolysis-deficient atlastin variant undergoes rapid GTP-dependent crossover dimerization and catalyzes fusion at an initial rate similar to WT atlastin. However, the variant cannot sustain fusion activity over time, implying a defect in subunit recycling. We suggest that GTP binding induces an atlastin conformational change that favors crossover dimerization for fusion and that the input of energy from nucleotide hydrolysis promotes complex disassembly for subunit recycling.

Initial Palivizumab Dose Administration in Outpatient Clinic After Hospital Discharge.

BACKGROUND: Palivizumab provides passive immunity for respiratory syncytial virus (RSV), but poor adherence compromises protection. A hospital initiative promoted administration of first palivizumab doses at an outpatient clinic immediately after discharge. The objectives of this study were to evaluate the impact of the initiative on location and timing of first palivizumab dose, patient adherence, reimbursement, acquisition cost and RSV-positive hospital readmissions. METHODS: This retrospective cohort study included pediatric patients who received palivizumab from 2012 to 2016. Three groups were compared: "before initiative," "transition" and "after initiative." Patients who did not qualify for palivizumab or who were eligible for palivizumab in previous RSV seasons were excluded. Multivariable logistic and linear regressions adjusted for patients' characteristics were used in outcome analysis. RESULTS: After adjusting for patients' characteristics, there was a 13.5-fold (95% confidence interval: 5.9-30.5, P < 0.0001) increase in odds that patients would receive outpatient administration of palivizumab and 2.7-fold (95% confidence interval: 1.3-5.7, P = 0.0103) increase in odds of receiving the second dose within 35 days after initiative implementation compared with before. Although there was no significant difference in reimbursement percentage after initiative implementation (32% ± 30% after initiative and 31% ± 22% before), calculated palivizumab acquisition costs were 20.8% lower. RSV readmissions were not significantly different. CONCLUSIONS: Implementation of an initiative with defined workflow, multidisciplinary collaboration, and early case management efforts to obtain insurance authorization increased outpatient administration of first palivizumab doses. Patient adherence improved as demonstrated by more timely receipt of the second palivizumab dose. There was no difference in reimbursement; however, acquisition cost decreased which is valuable considering low reimbursement rates. RSV-positive readmissions did not change significantly.

Impact of intercostal nerve blocks using liposomal versus standard bupivacaine on length of stay in minimally invasive thoracic surgery patients.

BACKGROUND: Postsurgical pain control can have a significant impact on patient outcomes and hospital-associated costs. We sought to evaluate the effect of intercostal nerve blocks using liposomal bupivacaine on length of stay (LOS) in patients undergoing video-assisted thoracoscopic surgery (VATS). METHODS: We retrospectively reviewed outcomes in 80 patients undergoing VATS wedge resection, VATS lobectomy, or minimally-invasive esophagectomy (MIE). Patients received either liposomal bupivacaine (n=40) or standard-release bupivacaine with epinephrine (n=40) via intercostal nerve block. The LOS, 24-hour postoperative pain scores, overall opioid usage, and patient ambulation rates at 24 hours were compared for the two groups. RESULTS: The median LOS was significantly shorter in patients receiving liposomal bupivacaine, at 1.35 days (IQR, 1.28 to 1.53 days) compared to 2.45 days (IQR, 2.08 to 3.51 days) in patients receiving standard-release bupivacaine (P<0.0001). Average post-operative pain score during the first 24 hours was 3.4±1.8 for the liposomal bupivacaine group and 2.3±1.2 for the control group (P=0.002). This difference, though statistically significant, is likely not clinically significant, as there was no difference in 24-hour postoperative intravenous morphine equivalent usage between the liposomal bupivacaine and control groups (29.8±21.0 vs. 31.9±20.9 mg, respectively, P=0.664). Interestingly, however, 93% (37/40) of patients receiving liposomal bupivacaine were able to ambulate within 24-hours after surgery, compared to 65% (26/40) of patients in the control group (P=0.003). CONCLUSIONS: The use of liposomal bupivacaine is associated with decreased LOS in postoperative thoracic surgery patients and earlier return to ambulation. It does not, however, decrease 24-hour postoperative pain scores or opioid usage.

Pediatric Lawnmower Injuries.

OBJECTIVE: The aim of this study was to evaluate demographics, characteristics, and mechanisms of injuries caused by lawnmowers in children. METHODS: Chart review from 1990 to 2010 at a level I pediatric trauma center identified patients younger than 18 years with lawnmower injuries. Demographics and characteristics of the injuries were analyzed by descriptive statistical analysis. RESULTS: The study identified 88 subjects, with 80% males and 42% of the subjects younger than 5 years. When the lawnmower type was specified, riding lawnmowers caused the majority of injuries (72%). The most common mechanism of injury was related to slipping under lawnmower/being run over (51%). The most common injuries were lacerations (36%), fractures (27%), and amputations (22%); lower extremities were injured more frequently than other body areas (62%). The majority of patients (76%) required hospitalization with a mean length of stay (LOS) of 9.7 days and a mean number of procedures of 4. Complications included 6 infections, 1 tissue necrosis, and 1 death from hemorrhagic shock. Riding-lawnmower injuries were associated with younger children (P < 0.0001). Riding lawnmowers and younger age were associated with longer hospital LOS (P = 0.01, 0.006) and increased number of procedures (P = 0.03, 0.003, respectively). CONCLUSIONS: Lawnmower injuries are still prevalent in children despite national safety recommendations. Injuries seen with riding lawnmowers were associated with younger age, higher number of procedures, longer LOS, and more severe injuries.

The crossover conformational shift of the GTPase atlastin provides the energy driving ER fusion.

The homotypic fusion of endoplasmic reticulum membranes is catalyzed by the atlastin GTPase. The mechanism involves trans-dimerization between GTPase heads and a favorable crossover conformational shift, catalyzed by GTP hydrolysis, that converts the dimer from a "prefusion" to "postfusion" state. However, whether crossover formation actually energizes fusion remains unclear, as do the sequence of events surrounding it. Here, we made mutations in atlastin to selectively destabilize the crossover conformation and used fluorescence-based kinetic assays to analyze the variants. All variants underwent dimerization and crossover concurrently, and at wild-type rates. However, certain variants were unstable once in the crossover dimer conformation, and crossover dimer stability closely paralleled lipid-mixing activity. Tethering, however, appeared to be unimpaired in all mutant variants. The results suggest that tethering and lipid mixing are catalyzed concurrently by GTP hydrolysis but that the energy requirement for lipid mixing exceeds that for tethering, and the full energy released through crossover formation is necessary for fusion.

Health Care Utilization of Veterans With Serious Mental Illness.

Outreach regarding veteran-specific factors can help determine which targeted interventions reduce the need for chronic mental illness inpatient hospitalization.

ER network formation and membrane fusion by atlastin1/SPG3A disease variants.

At least 38 distinct missense mutations in the neuronal atlastin1/SPG3A GTPase are implicated in an autosomal dominant form of hereditary spastic paraplegia (HSP), a motor-neurological disorder manifested by lower limb weakness and spasticity and length-dependent axonopathy of corticospinal motor neurons. Because the atlastin GTPase is sufficient to catalyze membrane fusion and required to form the ER network, at least in nonneuronal cells, it is logically assumed that defects in ER membrane morphogenesis due to impaired fusion activity are the primary drivers of SPG3A-associated HSP. Here we analyzed a subset of established atlastin1/SPG3A disease variants using cell-based assays for atlastin-mediated ER network formation and biochemical assays for atlastin-catalyzed GTP hydrolysis, dimer formation, and membrane fusion. As anticipated, some variants exhibited clear deficits. Surprisingly however, at least two disease variants, one of which represents that most frequently identified in SPG3A HSP patients, displayed wild-type levels of activity in all assays. The same variants were also capable of co-redistributing ER-localized REEP1, a recently identified function of atlastins that requires its catalytic activity. Taken together, these findings indicate that a deficit in the membrane fusion activity of atlastin1 may be a key contributor, but is not required, for HSP causation.

The Atlastin C-terminal tail is an amphipathic helix that perturbs the bilayer structure during endoplasmic reticulum homotypic fusion.

Fusion of tubular membranes is required to form three-way junctions found in reticular subdomains of the endoplasmic reticulum. The large GTPase Atlastin has recently been shown to drive endoplasmic reticulum membrane fusion and three-way junction formation. The mechanism of Atlastin-mediated membrane fusion is distinct from SNARE-mediated membrane fusion, and many details remain unclear. In particular, the role of the amphipathic C-terminal tail of Atlastin is still unknown. We found that a peptide corresponding to the Atlastin C-terminal tail binds to membranes as a parallel α helix, induces bilayer thinning, and increases acyl chain disorder. The function of the C-terminal tail is conserved in human Atlastin. Mutations in the C-terminal tail decrease fusion activity in vitro, but not GTPase activity, and impair Atlastin function in vivo. In the context of unstable lipid bilayers, the requirement for the C-terminal tail is abrogated. These data suggest that the C-terminal tail of Atlastin locally destabilizes bilayers to facilitate membrane fusion.

Mental illness and intensification of diabetes medications: an observational cohort study.

BACKGROUND: Mental health condition (MHC) comorbidity is associated with lower intensity care in multiple clinical scenarios. However, little is known about the effect of MHC upon clinicians' decisions about intensifying antiglycemic medications in diabetic patients with poor glycemic control. We examined whether delay in intensification of antiglycemic medications in response to an elevated Hemoglobin A1c (HbA1c) value is longer for patients with MHC than for those without MHC, and whether any such effect varies by specific MHC type. METHODS: In this observational study of diabetic Veterans Health Administration (VA) patients on oral antiglycemics with poor glycemic control (HbA1c ≥8) (N =52,526) identified from national VA databases, we applied Cox regression analysis to examine time to intensification of antiglycemics after an elevated HbA1c value in 2003-2004, by MHC status. RESULTS: Those with MHC were no less likely to receive intensification: adjusted Hazard Ratio [95% CI] 0.99 [0.96-1.03], 1.13 [1.04-1.23], and 1.12 [1.07-1.18] at 0-14, 15-30 and 31-180 days, respectively. However, patients with substance use disorders were less likely than those without substance use disorders to receive intensification in the first two weeks following a high HbA1c, adjusted Hazard Ratio 0.89 [0.81-0.97], controlling for sex, age, medical comorbidity, other specific MHCs, and index HbA1c value. CONCLUSIONS: For most MHCs, diabetic patients with MHC in the VA health care system do not appear to receive less aggressive antiglycemic management. However, the subgroup with substance use disorders does appear to have excess likelihood of non-intensification; interventions targeting this high risk subgroup merit attention.