GM1 gangliosidosis (GM1) is a fatal neurodegenerative lysosomal storage disease that occurs most commonly in young children, with no effective treatment available. Long-term follow-up of GM1 cats ...treated by bilateral thalamic and deep cerebellar nuclei (DCN) injection of adeno-associated virus (AAV)-mediated gene therapy has increased lifespan to 8 years of age, compared with an untreated lifespan of ~8 months. Due to risks associated with cerebellar injection in humans, the lateral ventricle was tested as a replacement route to deliver an AAVrh8 vector expressing feline β-galactosidase (β-gal), the defective enzyme in GM1. Treatment via the thalamus and lateral ventricle corrected storage, myelination, astrogliosis, and neuronal morphology in areas where β-gal was effectively delivered. Oligodendrocyte number increased, but only in areas where myelination was corrected. Reduced AAV and β-gal distribution were noted in the cerebellum with subsequent increases in storage, demyelination, astrogliosis, and neuronal degeneration. These postmortem findings were correlated with endpoint MRI and magnetic resonance spectroscopy (MRS). Compared with the moderate dose with which most cats were treated, a higher AAV dose produced superior survival, currently 6.5 years. Thus, MRI and MRS can predict therapeutic efficacy of AAV gene therapy and non-invasively monitor cellular events within the GM1 brain.
GM1 gangliosidosis is a fatal lysosomal disorder, for which there is no effective treatment. Adeno-associated virus (AAV) gene therapy in GM1 cats has resulted in a greater than 6-fold increase in ...lifespan, with many cats remaining alive at >5.7 years of age, with minimal clinical signs. Glycolipids are the principal storage product in GM1 gangliosidosis whose pathogenic mechanism is not completely understood. Targeted lipidomics analysis was performed to better define disease mechanisms and identify markers of disease progression for upcoming clinical trials in humans. 36 sphingolipids and subspecies associated with ganglioside biosynthesis were tested in the cerebrospinal fluid of untreated GM1 cats at a humane endpoint (∼8 months), AAV-treated GM1 cats (∼5 years old), and normal adult controls. In untreated GM1 cats, significant alterations were noted in 16 sphingolipid species, including gangliosides (GM1 and GM3), lactosylceramides, ceramides, sphingomyelins, monohexosylceramides, and sulfatides. Variable degrees of correction in many lipid metabolites reflected the efficacy of AAV gene therapy. Sphingolipid levels were highly predictive of neurologic disease progression, with 11 metabolites having a coefficient of determination (R
) > 0.75. Also, a specific detergent additive significantly increased the recovery of certain lipid species in cerebrospinal fluid samples. This report demonstrates the methodology and utility of targeted lipidomics to examine the pathophysiology of lipid storage disorders.
IMPORTANCE: The COVID-19 pandemic has affected youth mental health. Increases in site-specific eating disorder (ED) care have been documented; however, multisite studies demonstrating national trends ...are lacking. OBJECTIVE: To compare the number of adolescent/young adult patients seeking inpatient and outpatient ED care before and after onset of the COVID-19 pandemic. DESIGN, SETTING, AND PARTICIPANTS: Using an observational case series design, changes in volume in inpatient and outpatient ED-related care across 15 member sites (14 geographically diverse hospital-based adolescent medicine programs and 1 nonhospital-based ED program) of the US National Eating Disorder Quality Improvement Collaborative was examined. Sites reported monthly volumes of patients seeking inpatient and outpatient ED care between January 2018 and December 2021. Patient volumes pre- and postpandemic onset were compared separately for inpatient and outpatient settings. Demographic data such as race and ethnicity were not collected because this study used monthly summary data. EXPOSURES: Onset of the COVID-19 pandemic. MAIN OUTCOMES AND MEASURES: Monthly number of patients seeking inpatient/outpatient ED-related care. RESULTS: Aggregate total inpatient ED admissions were 81 in January 2018 and 109 in February 2020. Aggregate total new outpatient assessments were 195 in January 2018 and 254 in February 2020. Before the COVID-19 pandemic, the relative number of pooled inpatient ED admissions were increasing over time by 0.7% per month (95% CI, 0.2%-1.3%). After onset of the pandemic, there was a significant increase in admissions over time of 7.2% per month (95% CI, 4.8%-9.7%) through April 2021, then a decrease of 3.6% per month (95% CI, −6.0% to −1.1%) through December 2021. Prepandemic, pooled data showed relative outpatient ED assessment volume was stable over time, with an immediate 39.7% decline (95% CI, −50.4% to −26.7%) in April 2020. Subsequently, new assessments increased by 8.1% (95% CI, 5.3%-11.1%) per month through April 2021, then decreased by 1.5% per month (95% CI, −3.6% to 0.7%) through December 2021. The nonhospital-based ED program did not demonstrate a significant increase in the absolute number of admissions after onset of the pandemic but did see a significant increase of 8.2 (95% CI, 6.2-10.2) additional inquiries for care per month in the first year after onset of the pandemic. CONCLUSIONS AND RELEVANCE: In this study, there was a significant COVID-19 pandemic-related increase in both inpatient and outpatient volume of patients with EDs across sites, particularly in the first year of the pandemic. Given inadequate ED care availability prior to the pandemic, the increased postpandemic demand will likely outstrip available resources. Results highlight the need to address ED workforce and program capacity issues as well as improve ED prevention strategies.
Bacillus anthracis is a Gram-positive spore-forming bacterium that causes anthrax. With the increased threat of anthrax in biowarfare, there is an urgent need to characterize new antimicrobial ...targets from B. anthracis. One such target is dihydrodipicolinate synthase (DHDPS), which catalyzes the committed step in the pathway yielding meso-diaminopimelate and lysine. In this study, we employed CD spectroscopy to demonstrate that the thermostability of DHDPS from B. anthracis (Ba-DHDPS) is significantly enhanced in the presence of the substrate, pyruvate. Analytical ultracentrifugation studies show that the tetramer-dimer dissociation constant of the enzyme is 3-fold tighter in the presence of pyruvate compared with the apo form. To examine the significance of this substrate-mediated stabilization phenomenon, a dimeric mutant of Ba-DHDPS (L170E/G191E) was generated and shown to have markedly reduced activity compared with the wild-type tetramer. This demonstrates that the substrate, pyruvate, stabilizes the active form of the enzyme. We next determined the high resolution (2.15 Å) crystal structure of Ba-DHDPS in complex with pyruvate (3HIJ) and compared this to the apo structure (1XL9). Structural analyses show that there is a significant (91 Å2) increase in buried surface area at the tetramerization interface of the pyruvate-bound structure. This study describes a new mechanism for stabilization of the active oligomeric form of an antibiotic target from B. anthracis and reveals an “Achilles heel” that can be exploited in structure-based drug design.
BACKGROUND.Staphylococcus aureus bacteremia is a common complication of S. aureus infection. There are few pediatric studies defining the incidence and associated morbidity and mortality of S. aureus ...bacteremia and no such New Zealand studies. We conducted a prospective study of S. aureus bacteremia in children in New Zealand.
METHODS.From July 1, 1996 to December 31, 1998, we included all children <16 years of age with S. aureus bacteremia in Auckland and Christchurch. Relevant information regarding patient demographics, clinical course and outcome and laboratory results was recorded.
RESULTS.One hundred twenty-five cases of true S. aureus bacteremia were identified. There were 4 deaths within 30 days of the onset of bacteremia. Fourteen (11%) of the children were <1 month of age. Maori children (relative risk, 2.0; 95% confidence interval, 1.3 to 3.2) were twice as likely and Pacific Island children (relative risk, 2.5; 95% confidence interval, 1.6 to 3.8) 2.5 times as likely as white children to acquire S. aureus bacteremia. The peak incidence of S. aureus bacteremia was observed in Pacific Island children <1 year of age (105 cases/100 000 children/year). Twenty-seven percent of cases were related to intravenous catheters. Seventy percent of cases were community-acquired. Ninety-eight percent of non-catheter-related cases in children >1 month of age were community-acquired. There was a low rate of methicillin resistance (6%).
CONCLUSIONS.S. aureus bacteremia is largely community-acquired in children in New Zealand and is more common in Pacific Island and Maori populations. Although there is a low associated mortality, a significant number are potentially preventable cases secondary to intravenous catheters.
The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 ...MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to approximate the observed MCMA daytime patterns and absolute values of the VOC OH reactivity. The MOZART model is also in agreement with observations showing that NMHCs dominate the reactivity distribution except in the afternoon hours. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. A northeast transport event was studied in which air originating in the MCMA was intercepted aloft with the Department of Energy (DOE) G1 on 18 March and downwind with the National Center for Atmospheric Research (NCAR) C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind; ozone was shown to be photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial extent and temporal evolution of the plume and to help interpret the observed OH reactivity. The model results generally showed good agreement with experimental results for the total VOC OH reactivity downwind and gave insight into the distributions of VOC chemical classes. A box model with detailed gas phase chemistry (NCAR Master Mechanism), initialized with concentrations observed at one of the ground sites in the MCMA, was used to examine the expected evolution of specific VOCs over a 1–2 day period. The models clearly supported the experimental evidence for NMHC oxidation leading to the formation of OVOCs downwind, which then become the primary fuel for ozone production far away from the MCMA.
Dihydrodipicolinate synthase (DHDPS) catalyses the first committed step in the lysine‐biosynthesis pathway in bacteria, plants and some fungi. In this study, the expression of DHDPS from Bacillus ...anthracis (Ba‐DHDPS) and the purification of the recombinant enzyme in the absence and presence of the substrate pyruvate are described. It is shown that DHDPS from B. anthracis purified in the presence of pyruvate yields greater amounts of recombinant enzyme with more than 20‐fold greater specific activity compared with the enzyme purified in the absence of substrate. It was therefore sought to crystallize Ba‐DHDPS in the presence of the substrate. Pyruvate was soaked into crystals of Ba‐DHDPS prepared in 0.2 M sodium fluoride, 20%(w/v) PEG 3350 and 0.1 M bis‐tris propane pH 8.0. Preliminary X‐ray diffraction data of the recombinant enzyme soaked with pyruvate at a resolution of 2.15 Å are presented. The pending crystal structure of the pyruvate‐bound form of Ba‐DHDPS will provide insight into the function and stability of this essential bacterial enzyme.
Damage to specific brain circuits can cause specific neuropsychiatric symptoms. Therapeutic stimulation to these same circuits may modulate these symptoms. To determine whether these circuits ...converge, we studied depression severity after brain lesions (n = 461, five datasets), transcranial magnetic stimulation (n = 151, four datasets) and deep brain stimulation (n = 101, five datasets). Lesions and stimulation sites most associated with depression severity were connected to a similar brain circuit across all 14 datasets (P < 0.001). Circuits derived from lesions, deep brain stimulation and transcranial magnetic stimulation were similar (P < 0.0005), as were circuits derived from patients with major depression versus other diagnoses (P < 0.001). Connectivity to this circuit predicted out-of-sample antidepressant efficacy of transcranial magnetic stimulation and deep brain stimulation sites (P < 0.0001). In an independent analysis, 29 lesions and 95 stimulation sites converged on a distinct circuit for motor symptoms of Parkinson's disease (P < 0.05). We conclude that lesions, transcranial magnetic stimulation and DBS converge on common brain circuitry that may represent improved neurostimulation targets for depression and other disorders.
A high capacity F-actin affinity matrix is constructed by binding fluorescyl-actin to rabbit anti-fluorescein IgG that is covalently bound to Sepharose 4B. When stabilized with phalloidin, the actin ...remains associated with the Sepharose beads during repeated washes, activates the ATPase activity of myosin subfragment 1, and specifically binds 125I-heavy meromyosin and 125I-tropomyosin. The associations between the F-actin affinity matrix and the iodinated F-actin binding proteins are monitored both by affinity chromatography and by a rapid, low speed sedimentation assay. Anti-fluorescein IgG-Sepharose should be generally useful as a matrix for the immobilization of proteins containing accessible, covalently bound fluorescein groups.
Abstract
Robotics and autonomous systems are reshaping the world, changing healthcare, food production and biodiversity management. While they will play a fundamental role in delivering the UN ...Sustainable Development Goals, associated opportunities and threats are yet to be considered systematically. We report on a horizon scan evaluating robotics and autonomous systems impact on all Sustainable Development Goals, involving 102 experts from around the world. Robotics and autonomous systems are likely to transform how the Sustainable Development Goals are achieved, through replacing and supporting human activities, fostering innovation, enhancing remote access and improving monitoring. Emerging threats relate to reinforcing inequalities, exacerbating environmental change, diverting resources from tried-and-tested solutions and reducing freedom and privacy through inadequate governance. Although predicting future impacts of robotics and autonomous systems on the Sustainable Development Goals is difficult, thoroughly examining technological developments early is essential to prevent unintended detrimental consequences. Additionally, robotics and autonomous systems should be considered explicitly when developing future iterations of the Sustainable Development Goals to avoid reversing progress or exacerbating inequalities.
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