APOE Christchurch-mimetic therapeutic antibody reduces APOE-mediated toxicity and tau phosphorylation.

INTRODUCTION: We discovered that the APOE3 Christchurch (APOE3Ch) variant may provide resistance to Alzheimer's disease (AD). This resistance may be due to reduced pathological interactions between ApoE3Ch and heparan sulfate proteoglycans (HSPGs). METHODS: We developed and characterized the binding, structure, and preclinical efficacy of novel antibodies targeting human ApoE-HSPG interactions. RESULTS: We found that one of these antibodies, called 7C11, preferentially bound ApoE4, a major risk factor for sporadic AD, and disrupts heparin-ApoE4 interactions. We also determined the crystal structure of a Fab fragment of 7C11 and used computer modeling to predict how it would bind to ApoE. When we tested 7C11 in mouse models, we found that it reduced recombinant ApoE-induced tau pathology in the retina of MAPT*P301S mice and curbed pTau S396 phosphorylation in brains of systemically treated APOE4 knock-in mice. Targeting ApoE-HSPG interactions using 7C11 antibody may be a promising approach to developing new therapies for AD.

Resilience to autosomal dominant Alzheimer's disease in a Reelin-COLBOS heterozygous man.

We characterized the world's second case with ascertained extreme resilience to autosomal dominant Alzheimer's disease (ADAD). Side-by-side comparisons of this male case and the previously reported female case with ADAD homozygote for the APOE3 Christchurch (APOECh) variant allowed us to discern common features. The male remained cognitively intact until 67 years of age despite carrying a PSEN1-E280A mutation. Like the APOECh carrier, he had extremely elevated amyloid plaque burden and limited entorhinal Tau tangle burden. He did not carry the APOECh variant but was heterozygous for a rare variant in RELN (H3447R, termed COLBOS after the Colombia-Boston biomarker research study), a ligand that like apolipoprotein E binds to the VLDLr and APOEr2 receptors. RELN-COLBOS is a gain-of-function variant showing stronger ability to activate its canonical protein target Dab1 and reduce human Tau phosphorylation in a knockin mouse. A genetic variant in a case protected from ADAD suggests a role for RELN signaling in resilience to dementia.

Gliovascular alterations in sporadic and familial Alzheimer's disease: APOE3 Christchurch homozygote glioprotection.

In response to brain insults, astrocytes become reactive, promoting protection and tissue repair. However, astroglial reactivity is typical of brain pathologies, including Alzheimer's disease (AD). Considering the heterogeneity of the reactive response, the role of astrocytes in the course of different forms of AD has been underestimated. Colombia has the largest human group known to have familial AD (FAD). This group carries the autosomal dominant and fully penetrant mutation E280A in PSEN1, which causes early-onset AD. Recently, our group identified an E280A carrier who did not develop FAD. The individual was homozygous for the Christchurch mutation R136S in APOE3 (APOEch). Remarkably, APOE is the main genetic risk factor for developing sporadic AD (SAD) and most of cerebral ApoE is produced by astroglia. Here, we characterized astrocyte properties related to reactivity, glutamate homeostasis, and structural integrity of the gliovascular unit (GVU), as factors that could underlie the pathogenesis or protection of AD. Specifically, through histological and 3D microscopy analyses of postmortem samples, we briefly describe the histopathology and cytoarchitecture of the frontal cortex of SAD, FAD, and APOEch, and demonstrate that, while astrodegeneration and vascular deterioration are prominent in SAD, FAD is characterized by hyperreactive-like glia, and APOEch displays the mildest astrocytic and vascular alterations despite having the highest burden of Aß. Notably, astroglial, gliovascular, and vascular disturbances, as well as brain cell death, correlate with the specific astrocytic phenotypes identified in each condition. This study provides new insights into the potential relevance of the gliovasculature in the development and protection of AD. To our knowledge, this is the first study assessing the components of the GVU in human samples of SAD, FAD, and APOEch.

First-in-human in vivo genome editing via AAV-zinc-finger nucleases for mucopolysaccharidosis I/II and hemophilia B.

Zinc-finger nuclease (ZFN)-based in vivo genome editing is a novel treatment that can potentially provide lifelong protein replacement with single intravenous administration. Three first-in-human open-label ascending single-dose phase 1/2 studies were performed in parallel (starting November 2017) primarily to assess safety and tolerability of ZFN in vivo editing therapy in mucopolysaccharidosis I (MPS I) (n = 3), MPS II (n = 9), and hemophilia B (n = 1). Treatment was well tolerated with no serious treatment-related adverse events. At the 1e13 vg/kg dose, evidence of genome editing was detected through albumin-transgene fusion transcripts in liver for MPS II (n = 2) and MPS I (n = 1) subjects. The MPS I subject also had a transient increase in leukocyte iduronidase activity to the lower normal range. At the 5e13 vg/kg dose, one MPS II subject had a transient increase in plasma iduronate-2-sulfatase approaching normal levels and one MPS I subject approached mid-normal levels of leukocyte iduronidase activity with no evidence of genome editing. The hemophilia B subject was not able to decrease use of factor IX concentrate; genome editing could not be assessed. Overall, ZFN in vivo editing therapy had a favorable safety profile with evidence of targeted genome editing in liver, but no long-term enzyme expression in blood.

Remdesivir in kidney transplant patients with SARS-CoV-2 pneumonia.

BACKGROUND: Remdesivir is the only antiviral treatment that has been shown to be useful against SARS-CoV-2 infection. It shorts hospitalization time compared to placebo. Its effects in Kidney transplant (KT) patients are limited to some published cases. METHODS: We performed a retrospective observational study that included all KT patients admitted between August 01, 2020 and December 31, 2020 with SARS-CoV-2 pneumonia who received remdesivir. The objective of this study was to describe the experience of a cohort of KT patients treated with remdesivir. DISCUSSION: A total of 37 KT patients developed SARS-CoV-2 infection, 7 of them received treatment with remdesivir. The rest of the patients did not receive the drug due to either CKD-EPI less than 30 mL/min or they did not present clinical criteria. In addition to remdesivir, all pacients received dexamethasone and anticoagulation therapy. 4 were men, the median age was 59 (53-71) years. Median time from transplantation was 43 (16-82) months. Chest X-rays of all patients showed pulmonary infiltrates and required low oxygen flow therapy upon admission, requiring high flow nasal therapy in 3 cases. Only 2 cases presented deterioration of the graft function, not requiring hemodialysis in any case, and all recovered renal function at hospital discharge. 2 patients rise up 1.5 times the liver function test. No patient died or required admission to the critical care unit. Median days of admission was 12 (9-27) days. CONCLUSIONS: Our study suggests that the use of remdesivir could be useful in KT patients with SARS-CoV-2 pneumonia without side effects. Additional studies are necessary with a larger number of patients to improve the knowledge of this drug in SARS-CoV-2 infection.

Distinct tau neuropathology and cellular profiles of an APOE3 Christchurch homozygote protected against autosomal dominant Alzheimer's dementia.

We describe in vivo follow-up PET imaging and postmortem findings from an autosomal dominant Alzheimer's disease (ADAD) PSEN1 E280A carrier who was also homozygous for the APOE3 Christchurch (APOE3ch) variant and was protected against Alzheimer's symptoms for almost three decades beyond the expected age of onset. We identified a distinct anatomical pattern of tau pathology with atypical accumulation in vivo and unusual postmortem regional distribution characterized by sparing in the frontal cortex and severe pathology in the occipital cortex. The frontal cortex and the hippocampus, less affected than the occipital cortex by tau pathology, contained Related Orphan Receptor B (RORB) positive neurons, homeostatic astrocytes and higher APOE expression. The occipital cortex, the only cortical region showing cerebral amyloid angiopathy (CAA), exhibited a distinctive chronic inflammatory microglial profile and lower APOE expression. Thus, the Christchurch variant may impact the distribution of tau pathology, modulate age at onset, severity, progression, and clinical presentation of ADAD, suggesting possible therapeutic strategies.

Evidence of beta amyloid independent small vessel disease in familial Alzheimer's disease.

We studied small vessel disease (SVD) pathology in Familial Alzheimer's disease (FAD) subjects carrying the presenilin 1 (PSEN1) p.Glu280Ala mutation in comparison to those with sporadic Alzheimer's disease (SAD) as a positive control for Alzheimer's pathology and Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) bearing different NOTCH3 mutations, as positive controls for SVD pathology. Upon magnetic resonance imaging (MRI) in life, some FAD showed mild white matter hyperintensities and no further radiologic evidence of SVD. In post-mortem studies, total SVD pathology in cortical areas and basal ganglia was similar in PSEN1 FAD and CADASIL subjects, except for the feature of arteriosclerosis which was higher in CADASIL subjects than in PSEN1 FAD subjects. Further only a few SAD subjects showed a similar degree of SVD pathology as observed in CADASIL. Furthermore, we found significantly enlarged perivascular spaces in vessels devoid of cerebral amyloid angiopathy in FAD compared with SAD and CADASIL subjects. As expected, there was greater fibrinogen-positive perivascular reactivity in CADASIL but similar reactivity in PSEN1 FAD and SAD groups. Fibrinogen immunoreactivity correlated with onset age in the PSEN1 FAD cases, suggesting increased vascular permeability may contribute to cognitive decline. Additionally, we found reduced perivascular expression of PDGFRß AQP4 in microvessels with enlarged PVS in PSEN1 FAD cases. We demonstrate that there is Aß-independent SVD pathology in PSEN1 FAD, that was marginally lower than that in CADASIL subjects although not evident by MRI. These observations suggest presence of covert SVD even in PSEN1, contributing to disease progression. As is the case in SAD, these consequences may be preventable by early recognition and actively controlling vascular disease risk, even in familial forms of dementia.

Remdesivir en pacientes trasplantados renales con neumonía por SARS-CoV-2 / Remdesivir in kidney transplant patients with SARS-CoV-2 pneumonia

Introducción: El remdesivir es el único tratamiento antiviral que ha demostrado ser útil frente al SARS-CoV-2 acortando el tiempo de hospitalización frente a placebo. Su efecto en pacientes trasplantados renales (TR) se limita a algunos casos publicados.Material y métodosEstudio retrospectivo observacional de los pacientes TR que ingresaron entre el 1 de agosto de 2020 hasta el 31 de diciembre de 2020 con neumonía por SARS-CoV-2 y recibieron remdesivir.El objetivo es describir la experiencia de una cohorte de pacientes TR con neumonía por SARS-CoV-2 tratados con remdesivir.Resultados37 pacientes TR ingresaron por infección secundaria a SARS-CoV-2, 7 de ellos recibieron tratamiento con remdesivir. El resto de pacientes fueron excluidos por CKD-EPI menor a 30mL/min o por no presentar criterios clínicos. Además de remdesivir, todos recibieron dexametasona y anticoagulación. Cuatro eran hombres, siendo la mediana de edad de 59 (53-71) años. La mediana de tiempo post-trasplante fue de 43 (16-82) meses. Todos los pacientes presentaban neumonía y requirieron oxigenoterapia de bajo flujo al ingreso, precisando en tres de ellos oxigenoterapia de alto flujo durante el ingreso. Dos presentaron deterioro de la función del injerto al diagnóstico, no precisando en ningún caso hemodiálisis, y recuperándose al alta. Dos pacientes elevaron 1,5 veces el valor normal de las transaminasas. Ningún paciente falleció ni precisó ingreso en unidad de críticos. La mediana de días de ingreso fue de 12 (9-27) días.ConclusionesNuestro estudio sugiere que el uso de remdesivir podría ser útil en los pacientes TR con neumonía por SARS-CoV-2 sin presentar efectos secundarios. Son necesarios más estudios con un mayor número de pacientes para ampliar el conocimiento de este fármaco en la infección por SARS-CoV-2. (AU)

Background: Remdesivir is the only antiviral treatment that has been shown to be useful against SARS-CoV-2 infection. It shorts hospitalization time compared to placebo. Its effects in kidney transplant (KT) patients are limited to some published cases.MethodsWe performed a retrospective observational study that included all KT patients admitted between August 1st, 2020 and December 31st, 2020 with SARS-CoV-2 pneumonia who received remdesivir.The objective of this study was to describe the experience of a cohort of KT patients treated with remdesivir.DiscussionA total of 37 KT patients developed SARS-CoV-2 infection, 7 of them received treatment with remdesivir. The rest of the patients did not receive the drug due to either CKD-EPI less than 30mL/min or they did not present clinical criteria. In addition to remdesivir, all patients received dexamethasone and anticoagulation therapy. 4 were men, the median age was 59 (53–71) years. Median time from transplantation was 43 (16–82) months. Chest X-rays of all patients showed pulmonary infiltrates and required low-oxygen flow therapy upon admission, requiring high-flow nasal therapy in 3 cases. Only 2 cases presented deterioration of the graft function, not requiring hemodialysis in any case, and all recovered renal function at hospital discharge. 2 patients rise up 1.5 times the liver function test. No patient died or required admission to the critical care unit. Median days of admission was 12 (9–27) days.ConclusionsOur study suggests that the use of remdesivir could be useful in KT patients with SARS-CoV-2 pneumonia without side effects. Additional studies are necessary with a larger number of patients to improve the knowledge of this drug in SARS-CoV-2 infection. (AU)

[Remdesivir in kidney transplant patients with SARS-CoV-2 pneumonia]. / Remdesivir en pacientes trasplantados renales con neumonía por SARS-CoV-2.

Background: Remdesivir is the only antiviral treatment that has been shown to be useful against SARS-CoV-2 infection. It shorts hospitalization time compared to placebo. Its effects in kidney transplant (KT) patients are limited to some published cases. Methods: We performed a retrospective observational study that included all KT patients admitted between August 1st, 2020 and December 31st, 2020 with SARS-CoV-2 pneumonia who received remdesivir.The objective of this study was to describe the experience of a cohort of KT patients treated with remdesivir. Discussion: A total of 37 KT patients developed SARS-CoV-2 infection, 7 of them received treatment with remdesivir. The rest of the patients did not receive the drug due to either CKD-EPI less than 30 mL/min or they did not present clinical criteria. In addition to remdesivir, all patients received dexamethasone and anticoagulation therapy. 4 were men, the median age was 59 (53-71) years. Median time from transplantation was 43 (16-82) months. Chest X-rays of all patients showed pulmonary infiltrates and required low-oxygen flow therapy upon admission, requiring high-flow nasal therapy in 3 cases. Only 2 cases presented deterioration of the graft function, not requiring hemodialysis in any case, and all recovered renal function at hospital discharge. 2 patients rise up 1.5 times the liver function test. No patient died or required admission to the critical care unit. Median days of admission was 12 (9-27) days. Conclusions: Our study suggests that the use of remdesivir could be useful in KT patients with SARS-CoV-2 pneumonia without side effects. Additional studies are necessary with a larger number of patients to improve the knowledge of this drug in SARS-CoV-2 infection.

The Impact of Age on Mortality in Chronic Haemodialysis Popu-Lation with COVID-19.

Age and chronic kidney disease have been described as mortality risk factors for coronavirus disease 2019 (COVID-19). Currently, an important percentage of patients in haemodialysis are elderly. Herein, we investigated the impact of age on mortality among haemodialysis patients with COVID-19. Data was obtained from the Spanish COVID-19 chronic kidney disease (CKD) Working Group Registry. From 18 March 2020 to 27 August 2020, 930 patients on haemodialysis affected by COVID-19 were included in the Registry. A total of 254 patients were under 65 years old and 676 were 65 years or older (elderly group). Mortality was 25.1% higher (95% CI: 22.2-28.0%) in the elderly as compared to the non-elderly group. Death from COVID-19 was increased 6.2-fold in haemodialysis patients as compared to the mortality in the general population in a similar time frame. In the multivariate Cox regression analysis, age (hazard ratio (HR) 1.59, 95% CI: 1.31-1.93), dyspnea at presentation (HR 1.51, 95% CI: 1.11-2.04), pneumonia (HR 1.74, 95% CI: 1.10-2.73) and admission to hospital (HR 4.00, 95% CI: 1.83-8.70) were identified as independent mortality risk factors in the elderly haemodialysis population. Treatment with glucocorticoids reduced the risk of death (HR 0.68, 95% CI: 0.48-0.96). In conclusion, mortality is dramatically increased in elderly haemodialysis patients with COVID-19. Our results suggest that this high risk population should be prioritized in terms of protection and vaccination.

Extracellular Vesicles From 3xTg-AD Mouse and Alzheimer's Disease Patient Astrocytes Impair Neuroglial and Vascular Components.

Astrocytes are specialized glial cells that are essential components of the neurovascular unit (NVU) and are involved in neurodevelopment, brain maintenance and repair, and neurodegeneration. Astrocytes mediate these processes by releasing cellular mediators such as extracellular vesicles (EVs). EVs are vehicles of cell-cell communication and have been proposed as mediators of damage in AD. However, the transcellular mechanism by which Alzheimer disease (AD) astrocytes impair the function of NVU components is poorly understood. Therefore, we evaluated the effects of adult PS1-KI and 3xTg-AD astrocyte conditioned media (CM) and EVs on NVU components (neuroglia and endothelium) in vitro. Additionally, SAD and FAD astrocyte-derived EVs (A-EVs) were characterized, and we evaluated their effects on NVU in cocultured cells in vitro and on intrahippocampal CA1 cells in vivo. Surprisingly, cultured 3xTg-AD astrocytes showed increased glial fibrillary acidic protein (GFAP) reactivity compared to PS1-KI astrocytes, which denotes astrocytic hyperreactivity. CM from adult mice 3xTg-AD astrocytes increased cell-cell gaps between endothelial cells, filopodia-like dendritic protrusions in neurons and neuronal and endothelial cell death. 3xTg-AD A-EVs induced neurotoxicity and increased astrocyte GFAP reactivity. Cultured human postmortem astrocytes from AD patients also increased GFAP reactivity and EVs release. No differences in the size or number of A-EVs were detected between AD and control samples; however, both SAD and FAD A-EVs showed increased expression of the surface marker aquaporin 4. A-EVs induced cytotoxicity and astrocyte hyperactivation: specifically, FAD A-EVs induced neuroglial cytotoxicity and increased gaps between the endothelium, while SAD A-EVs mainly altered the endothelium. Similarly, both AD A-EVs increased astrocyte GS reactivity and vascular deterioration in vivo. We associated this finding with perivascular reactive astrocytes and vascular deterioration in the human AD brain. In summary, these results suggest that AD A-EVs impair neuroglial and vascular components.

Measuring the marginal costs of reducing water leakage: the case of water and sewerage utilities in Chile.

Water leakage in the urban water cycle involves relevant economic, social, and environmental negative impacts. Thus, reducing water leakage is a key challenge for both water regulators and water companies. This study estimated the evolution (2007-2015) of the marginal cost of improving the quality of service in terms of water leakage in the Chilean water industry, which involves full private, concessionary, and public water companies. In water companies, management skills and efforts play an important role in meeting water leakage targets. Thus, this study employed a cost frontier model where it was assumed that unobserved management ability interacts with output and water leakage factors. The results reveal high levels of cost efficiency for the average water company. Management increases outputs and reduces water leakage and, thus, has a positive impact on costs and efficiency. The marginal cost of reducing water leakage is higher for the public water company than for private and concessionary water companies. The average estimated marginal cost of reducing water leakage was 0.349 €/m3, which means that a water company has to spend an extra 0.349 € in operating costs to avoid a cubic meter of water leakage. Some policy implications were discussed based on the results of this study.

Differential Profile of Systemic Extracellular Vesicles From Sporadic and Familial Alzheimer's Disease Leads to Neuroglial and Endothelial Cell Degeneration.

Evidence suggests that extracellular vesicles (EVs) act as mediators and biomarkers of neurodegenerative diseases. Two distinct forms of Alzheimer disease (AD) are known: a late-onset sporadic form (SAD) and an early-onset familial form (FAD). Recently, neurovascular dysfunction and altered systemic immunological components have been linked to AD neurodegeneration. Therefore, we characterized systemic-EVs from postmortem SAD and FAD patients and evaluated their effects on neuroglial and endothelial cells. We found increase CLN-5 spots with vesicular morphology in the abluminal portion of vessels from SAD patients. Both forms of AD were associated with larger and more numerous systemic EVs. Specifically, SAD patients showed an increase in endothelial- and leukocyte-derived EVs containing mitochondria; in contrast, FAD patients showed an increase in platelet-derived EVs. We detected a differential protein composition for SAD- and FAD-EVs associated with the coagulation cascade, inflammation, and lipid-carbohydrate metabolism. Using mono- and cocultures (endothelium-astrocytes-neurons) and human cortical organoids, we showed that AD-EVs induced cytotoxicity. Both forms of AD featured decreased neuronal branches area and astrocytic hyperreactivity, but SAD-EVs led to greater endothelial detrimental effects than FAD-EVs. In addition, FAD- and SAD-EVs affected calcium dynamics in a cortical organoid model. Our findings indicate that the phenotype of systemic AD-EVs is differentially defined by the etiopathology of the disease (SAD or FAD), which results in a differential alteration of the NVU cells implied in neurodegeneration.

5-CQA and Mangiferin, Two Leaf Biomarkers of Adaptation to Full Sun or Shade Conditions in Coffea arabica L.

Phenolic compounds are involved in plant response to environmental conditions and are highly present in leaves of Coffea arabica L., originally an understory shrub. To increase knowledge of C. arabica leaf phenolic compounds and their patterns in adaptation to light intensity, mature leaves of Ethiopian wild accessions, American pure lines and their relative F1 hybrids were sampled in full sun or under 50% shade field plots in Mexico and at two contrasting elevations in Nicaragua and Colombia. Twenty-one phenolic compounds were identified by LC-DAD-MS2 and sixteen were quantified by HPLC-DAD. Four of them appeared to be involved in C. arabica response to light intensity. They were consistently more accumulated in full sun, presenting a stable ratio of leaf content in the sun vs. shade for all the studied genotypes: 1.6 for 5-CQA, F-dihex and mangiferin and 2.8 for rutin. Moreover, 5-CQA and mangiferin contents, in full sun and shade, allowed for differentiating the two genetic groups of Ethiopian wild accessions (higher contents) vs. cultivated American pure lines. They appear, therefore, to be potential biomarkers of adaptation of C. arabica to light intensity for breeding programs. We hypothesize that low 5-CQA and mangiferin leaf contents should be searched for adaptation to full-sun cropping systems and high contents used for agroforestry systems.

Decreased Deposition of Beta-Amyloid 1-38 and Increased Deposition of Beta-Amyloid 1-42 in Brain Tissue of Presenilin-1 E280A Familial Alzheimer's Disease Patients.

Familial Alzheimer's Disease (FAD) caused by Presenilin-1 (PS1) mutations is characterized by early onset, cognitive impairment, and dementia. Impaired gamma secretase function favors production of longer beta-amyloid species in PS1 FAD. The PS1 E280A mutation is the largest FAD kindred under study. Here, we studied beta-amyloid deposits in PS1 E280A FAD brains in comparison to sporadic Alzheimer's disease (SAD). We analyzed cortices and cerebellum from 10 FAD and 10 SAD brains using immunohistochemistry to determine total beta-amyloid, hyperphosphorylated tau (pTau), and specific beta-amyloid peptides 1-38, 1-40, 1-42, and 1-43. Additionally, we studied beta-amyloid subspecies by ELISA, and vessel pathology was detected with beta-amyloid 1-42 and truncated pyroglutamylated beta-amyloid antibodies. There were no significant differences in total beta-amyloid signal between SAD and FAD. Beta-amyloid 1-38 and 1-43 loads were increased, and 1-42 loads were decreased in frontal cortices of SAD when compared to FAD. Beta-amyloid species assessment by ELISA resembled our findings by immunohistochemical analysis. Differences in beta-amyloid 1-38 and 1-42 levels between SAD and FAD were evidenced by using beta-amyloid length-specific antibodies, reflecting a gamma secretase-dependent shift in beta-amyloid processing in FAD cases. The use of beta-amyloid length-specific antibodies for postmortem assessment of beta-amyloid pathology can differentiate between SAD and PS1 FAD cases and it can be useful for identification of SAD cases potentially affected with gamma secretase dysfunction.

Discriminative Accuracy of Plasma Phospho-tau217 for Alzheimer Disease vs Other Neurodegenerative Disorders.

Importance: There are limitations in current diagnostic testing approaches for Alzheimer disease (AD). Objective: To examine plasma tau phosphorylated at threonine 217 (P-tau217) as a diagnostic biomarker for AD. Design, Setting, and Participants: Three cross-sectional cohorts: an Arizona-based neuropathology cohort (cohort 1), including 34 participants with AD and 47 without AD (dates of enrollment, May 2007-January 2019); the Swedish BioFINDER-2 cohort (cohort 2), including cognitively unimpaired participants (n = 301) and clinically diagnosed patients with mild cognitive impairment (MCI) (n = 178), AD dementia (n = 121), and other neurodegenerative diseases (n = 99) (April 2017-September 2019); and a Colombian autosomal-dominant AD kindred (cohort 3), including 365 PSEN1 E280A mutation carriers and 257 mutation noncarriers (December 2013-February 2017). Exposures: Plasma P-tau217. Main Outcomes and Measures: Primary outcome was the discriminative accuracy of plasma P-tau217 for AD (clinical or neuropathological diagnosis). Secondary outcome was the association with tau pathology (determined using neuropathology or positron emission tomography [PET]). Results: Mean age was 83.5 (SD, 8.5) years in cohort 1, 69.1 (SD, 10.3) years in cohort 2, and 35.8 (SD, 10.7) years in cohort 3; 38% were women in cohort 1, 51% in cohort 2, and 57% in cohort 3. In cohort 1, antemortem plasma P-tau217 differentiated neuropathologically defined AD from non-AD (area under the curve [AUC], 0.89 [95% CI, 0.81-0.97]) with significantly higher accuracy than plasma P-tau181 and neurofilament light chain (NfL) (AUC range, 0.50-0.72; P < .05). The discriminative accuracy of plasma P-tau217 in cohort 2 for clinical AD dementia vs other neurodegenerative diseases (AUC, 0.96 [95% CI, 0.93-0.98]) was significantly higher than plasma P-tau181, plasma NfL, and MRI measures (AUC range, 0.50-0.81; P < .001) but not significantly different compared with cerebrospinal fluid (CSF) P-tau217, CSF P-tau181, and tau-PET (AUC range, 0.90-0.99; P > .15). In cohort 3, plasma P-tau217 levels were significantly greater among PSEN1 mutation carriers, compared with noncarriers, from approximately 25 years and older, which is 20 years prior to estimated onset of MCI among mutation carriers. Plasma P-tau217 levels correlated with tau tangles in participants with (Spearman ρ = 0.64; P < .001), but not without (Spearman ρ = 0.15; P = .33), ß-amyloid plaques in cohort 1. In cohort 2, plasma P-tau217 discriminated abnormal vs normal tau-PET scans (AUC, 0.93 [95% CI, 0.91-0.96]) with significantly higher accuracy than plasma P-tau181, plasma NfL, CSF P-tau181, CSF Aß42:Aß40 ratio, and MRI measures (AUC range, 0.67-0.90; P < .05), but its performance was not significantly different compared with CSF P-tau217 (AUC, 0.96; P = .22). Conclusions and Relevance: Among 1402 participants from 3 selected cohorts, plasma P-tau217 discriminated AD from other neurodegenerative diseases, with significantly higher accuracy than established plasma- and MRI-based biomarkers, and its performance was not significantly different from key CSF- or PET-based measures. Further research is needed to optimize the assay, validate the findings in unselected and diverse populations, and determine its potential role in clinical care.

Estimating technical efficiency and allocative distortions of water companies: evidence from the English and Welsh water and sewerage industry.

Regulated water industries need to improve their technical efficiency and allocate their resources efficiently. This is the case of the water industry in England and Wales which was privatized in 1989, and the method of price cap regulation was implemented. This study uses an input distance function system approach to estimate the technical efficiency and distortions in the choice of input mixes for the English and Welsh water and sewerage companies (WaSCs) over the years 1991-2016. The results indicated that an average WaSC was 75.3% technically efficient which means that inputs could be reduced by 24.7% keeping the level of output constant. On average, the input mix was considered to be allocated inefficiently as there was an over-utilization of capital and other inputs relative to employment. Moreover, the low degree of substitutability among inputs implied that reducing allocative inefficiency could be costly. The findings of our study is of interest to policy makers who want to implement effective policies to improve efficiency in the water industry.

Plasma neurofilament light chain in the presenilin 1 E280A autosomal dominant Alzheimer's disease kindred: a cross-sectional and longitudinal cohort study.

BACKGROUND: Neurofilament light chain (NfL) is a promising biomarker of active axonal injury and neuronal degeneration. We aimed to characterise cross-sectional and longitudinal plasma NfL measurements and determine the age at which NfL concentrations begin to differentiate between carriers of the presenilin 1 (PSEN1) E280A (Glu280Ala) mutation and age-matched non-carriers from the Colombian autosomal dominant Alzheimer's disease kindred. METHODS: In this cross-sectional and longitudinal cohort study, members of the familial Alzheimer's disease Colombian kindred aged 8-75 years with no other neurological or health conditions were recruited from the Alzheimer's Prevention Initiative Registry at the University of Antioquia (Medellín, Colombia) between Aug 1, 1995, and Dec 15, 2018. We used a single molecule array immunoassay and log-transformed data to examine the relationship between plasma NfL concentrations and age, and establish the earliest age at which NfL concentrations begin to diverge between mutation carriers and non-carriers. FINDINGS: We enrolled a cohort of 1070 PSEN1 E280A mutation carriers and 1074 non-carriers with baseline assessments; of these participants, longitudinal measures (with a mean follow-up of 6 years) were available for 242 mutation carriers and 262 non-carriers. Plasma NfL measurements increased with age in both groups (p<0·0001), and began to differentiate carriers from non-carriers when aged 22 years (22 years before the estimated median age at mild cognitive impairment onset of 44 years), although the ability of plasma NfL to discriminate between carriers and non-carriers only reached high sensitivity close to the age of clinical onset. INTERPRETATION: Our findings further support the promise of plasma NfL as a biomarker of active neurodegeneration in the detection and tracking of Alzheimer's disease and the evaluation of disease-modifying therapies. FUNDING: National Institute on Aging, National Institute of Neurological Disorders and Stroke, Banner Alzheimer's Foundation, COLCIENCIAS, the Torsten Söderberg Foundation, the Swedish Research Council, the Swedish Alzheimer Foundation, the Swedish Brain Foundation, and the Swedish state under the ALF-agreement.

The cost of reducing unplanned water supply interruptions: A parametric shadow price approach.

Water companies are responsible for supplying water to customers 24 h per day. However, due to extreme natural events and/or anthropogenic actions, water companies suffer from unplanned water supply interruptions, which directly impact customers and incur expenses by the companies. In this study, for the first time, we estimated the shadow price (or implicit cost) of unplanned water supply interruptions using stochastic frontier techniques for a sample of 21 Chilean water companies over the period of 2007-2017. The results indicate that, on average, the Chilean water company needed to spend an extra 2.547€ in operating expenditures to avoid 1 h of interruption. Average shadow price of unplanned water supply interruptions was higher for concessionary and full private companies than public ones. These findings demonstrate that the regulatory agency may need to promote effective policies and incentives to ensure and improve the continuity of the water supply. This is very relevant to the Chilean water industry, where there is an ongoing policy debate regarding the use of penalties and compensations as an incentive to avoid unplanned water supply interruptions.

Familial Alzheimer's Disease and Recessive Modifiers.

Alzheimer's disease (AD) is progressive brain disorder that affects ~ 50 million people worldwide and has no current effective treatment. AD age of onset (ADAOO) has shown to be critical for the identification of genes that modify the appearance of AD signs and symptoms in a specific population. We clinically characterized and whole-exome genotyped 71 individuals with AD from the Paisa genetic isolate, segregating the (PSEN1) E280A dominant fully penetrant mutation, and analyzed the potential recessive effects of ~ 50,000 common functional genomic variants to the ADAOO. Standard quality control and filtering procedures were applied, and recessive single- and multi-locus linear mixed-effects models were used. We identified genetic variants in the SLC9C1, CSN1S1, and LOXL4 acting recessively to delay ADAOO up to ~ 11, ~ 6, and ~ 9 years on average, respectively. In contrast, the CC recessive genotype in marker DHRS4L2-rs2273946 accelerates ADAOO by ~ 8 years. This study, reports new recessive variants modifying ADAOO in PSEN1 E280A mutation carriers. This set of genes are implicated in important biological processes and molecular functions commonly affected by genes associated with the etiology of AD such as APP, APOE, and CLU. Future functional studies using modern techniques such as induced pluripotent stem cells will allow a better understanding of the over expression and down regulation of these recessive modifier variants and hence the pathogenesis of AD. These results are important for prediction of AD and ultimately, substantial to develop new therapeutic strategies for individuals at risk or affected by AD.