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1.
J Biol Chem ; 299(10): 105167, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37595873

RESUMEN

Microbial extracellular reduction of insoluble compounds requires soluble electron shuttles that diffuse in the environment, freely diffusing cytochromes, or direct contact with cellular conductive appendages that release or harvest electrons to assure a continuous balance between cellular requirements and environmental conditions. In this work, we produced and characterized the three cytochrome domains of PgcA, an extracellular triheme cytochrome that contributes to Fe(III) and Mn(IV) oxides reduction in Geobacter sulfurreducens. The three monoheme domains are structurally homologous, but their heme groups show variable axial coordination and reduction potential values. Electron transfer experiments monitored by NMR and visible spectroscopy show the variable extent to which the domains promiscuously exchange electrons while reducing different electron acceptors. The results suggest that PgcA is part of a new class of cytochromes - microbial heme-tethered redox strings - that use low-complexity protein stretches to bind metals and promote intra- and intermolecular electron transfer events through its cytochrome domains.

2.
Biochem Soc Trans ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38979638

RESUMEN

Cytokinins (CKs) are phytohormones structurally similar to purines that play important roles in various aspects of plant physiology and development. The local and long-distance distribution of CKs is very important to control their action throughout the plant body. Over the past decade, several novel CK transporters have been described, many of which have been linked to a physiological function rather than simply their ability to transport the hormone in vitro. Purine permeases, equilibrative nucleotide transporters and ATP-binding cassette transporters are involved in the local and long-range distribution of CK. In addition, members of the Arabidopsis AZA-GUANINE RESISTANT (AZG) protein family, AZG1 and AZG2, have recently been shown to mediate CK uptake at the plasma membrane and endoplasmic reticulum. Despite sharing ∼50% homology, AZG1 and AZG2 have unique transport mechanisms, tissue-specific expression patterns, and subcellular localizations that underlie their distinct physiological functions. AZG2 is expressed in a small group of cells in the overlying tissue around the lateral root primordia, where its expression is induced by auxins and it is involved in the regulation of lateral root growth. AZG1 is ubiquitously expressed, with high levels in the division zone of the root apical meristem. Here, it binds and stabilises the auxin efflux carrier PIN1, thereby shaping root architecture, particularly under salt stress. This review highlights the latest findings on the protein properties, transport mechanisms and cellular functions of this new family of CK transporters and discusses perspectives for future research in this field.

3.
MMWR Morb Mortal Wkly Rep ; 73(8): 175-179, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38421946

RESUMEN

Surveillance data can provide rapid, within-season influenza vaccine effectiveness (VE) estimates to guide public health recommendations. Mandatory reporting of influenza vaccine administration to California's immunization information registry began January 1, 2023, and mandatory reporting of all influenza laboratory test results, including negative results, was instituted in California on June 15, 2023. These data, collected by the California Department of Public Health during October 1, 2023-January 31, 2024, were used to calculate interim influenza VE against laboratory-confirmed influenza by comparing the odds of vaccination among case-patients (persons who received a positive influenza laboratory test result) and control patients (those who received a negative influenza laboratory test result). VE was calculated as 1 - adjusted odds ratio using mixed-effects logistic regression, with age, race, and ethnicity as fixed effects and specimen collection week and county as random effects. Overall, during October 1, 2023-January 31, 2024, estimated VE was 45% among persons aged ≥6 months, 56% among children and adolescents aged 6 months-17 years, 48% among adults aged 18-49 years, 36% among those aged 50-64 years, and 30% among those aged ≥65 years. Consistent with some previous influenza seasons, influenza vaccination provided moderate protection against laboratory-confirmed influenza among infants, children, adolescents, and adults. All persons aged ≥6 months without a contraindication to vaccination should receive annual influenza vaccination to reduce influenza illness, severe influenza, and strain on health care resources. Influenza vaccination remains the best way to prevent influenza.


Asunto(s)
Vacunas contra la Influenza , Gripe Humana , Adolescente , Adulto , Niño , Lactante , Humanos , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Eficacia de las Vacunas , Vacunación , California/epidemiología
4.
J Surg Oncol ; 129(5): 939-944, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38221657

RESUMEN

This study presents a new technique for robotic-assisted intracorporeal rectal transection and hand-sewn anastomosis for low anterior resection that overcomes some limitations of conventional techniques. By integrating the advantages of the robotic platform, ensuring standardized exposure during rectal transection, and emphasizing the importance of avoiding complications associated with staple crossings, this innovation has the potential to significantly improve outcomes and reduce costs for patients with lower rectal tumors.


Asunto(s)
Laparoscopía , Neoplasias del Recto , Procedimientos Quirúrgicos Robotizados , Humanos , Laparoscopía/métodos , Recto/cirugía , Recto/patología , Anastomosis Quirúrgica/métodos , Neoplasias del Recto/cirugía , Neoplasias del Recto/patología
5.
Pediatr Transplant ; 28(1): e14697, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38317342

RESUMEN

BACKGROUND: In adults, pretransplant malignancy (PTM) negatively impacts patient survival due to immunosuppression regimens influencing post-transplantation tumor growth. Few reports investigate the outcomes of pediatric kidney transplantation with PTM. We compare transplant outcomes for pediatric patients with PTM to matched controls, including cancer types extending beyond Wilms tumor. METHODS: The United Network of Organ Sharing Database was queried to identify pediatric transplant recipients with histories of PTM. All PTM patients were matched to non-PTM patients, at a 1:1 ratio, with 0.001 match tolerance. Matching variables included transplant year, recipient age, recipient gender, recipient race, donor type, and prior transplant. Death-censored graft and patient survival were analyzed. All statistics were reported with 95% confidence intervals (CI). RESULTS: After propensity matching, 285 PTM and 285 non-PTM patients were identified, with transplant dates from 1990 to 2020. Median Kidney Donor Profile Index values were comparable between cohorts, 17% and 12%, respectively (p = .065). Kaplan-Meier analysis revealed that PTM patients did not have a significantly different rate of death-censored graft failure, compared to the non-PTM group [HR 0.76; 95% CI (0.54-1.1)]. There was also no difference in the overall survival between the two groups of patients [HR 1.1; 95% CI (0.66-2.0)]. CONCLUSION: A history of pediatric malignancy has minimal independent effect on their post-transplant survival. Additionally, pediatric patients with PTM demonstrated equivalent rates of graft survival. Thus, in contrast to adults, renal failure in children with history of pediatric malignancies should not be considered a complicating factor for renal transplantation.


Asunto(s)
Neoplasias Renales , Trasplante de Riñón , Tumor de Wilms , Adulto , Humanos , Niño , Donantes de Tejidos , Factores de Riesgo , Tumor de Wilms/complicaciones , Tumor de Wilms/cirugía , Complicaciones Posoperatorias/epidemiología , Supervivencia de Injerto , Estudios Retrospectivos , Rechazo de Injerto
6.
Euro Surveill ; 29(16)2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38639093

RESUMEN

BackgroundMpox, caused by monkeypox virus (MPXV), was considered a rare zoonotic disease before May 2022, when a global epidemic of cases in non-endemic countries led to the declaration of a Public Health Emergency of International Concern. Cases of mpox in Ireland, a country without previous mpox reports, could reflect extended local transmission or multiple epidemiological introductions.AimTo elucidate the origins and molecular characteristics of MPXV circulating in Ireland between May 2022 and October 2023.MethodsWhole genome sequencing of MPXV from 75% of all Irish mpox cases (182/242) was performed and compared to sequences retrieved from public databases (n = 3,362). Bayesian approaches were used to infer divergence time between sequences from different subclades and evaluate putative importation events from other countries.ResultsOf 242 detected mpox cases, 99% were males (median age: 35 years; range: 15-60). All 182 analysed genomes were assigned to Clade IIb and, presence of 12 distinguishable subclades suggests multiple introductions into Ireland. Estimation of time to divergence of subclades further supports the hypothesis for multiple importation events from numerous countries, indicative of extended and sustained international spread of mpox. Further analysis of sequences revealed that 92% of nucleotide mutations were from cytosine to thymine (or from guanine to adenine), leading to a high number of non-synonymous mutations across subclades; mutations associated with tecovirimat resistance were not observed.ConclusionWe provide insights into the international transmission dynamics supporting multiple introductions of MPXV into Ireland. Such information supported the implementation of evidence-informed public health control measures.


Asunto(s)
Monkeypox virus , Mpox , Masculino , Humanos , Adulto , Femenino , Irlanda/epidemiología , Monkeypox virus/genética , Teorema de Bayes , Mpox/diagnóstico , Mpox/epidemiología , Brotes de Enfermedades
7.
Folia Phoniatr Logop ; 76(1): 68-76, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37487470

RESUMEN

INTRODUCTION: Voice disorders and burnout syndrome are common among teachers. This study aimed to explore the relationship among vocal problems, burnout syndrome, and some personal work factors. METHODS: This cross-sectional descriptive study enrolled 90 nonuniversity teachers who completed the Multidimensional Vocal Scale for Teachers (EVM-D) to evaluate vocal problems and an adapted Spanish version of the Maslach Burnout Inventory-Educators Survey (MBI-ES) to detect burnout syndrome. RESULTS: Overall, 16% of teachers expressed symptoms compatible with burnout, and 60% of them were in the interval above the 75th percentile of the EVM-D, i.e., they had a high risk of vocal problems. An association between burnout and more vocal problems was established among teachers, particularly between the vocal symptoms and vocal abuse dimensions with the emotional exhaustion subscale of the MBI-ES. A history of anxiety/depression and fewer years of professional experience were associated with more vocal problems. The burnout group perceived more "loss of vocal power," "vocal fatigue," "vocal effort," and "hoarseness." Vocal abuse items received the highest scores of EVM-D. However, only "shouting" in the classroom was significantly different between the groups with and without burnout. CONCLUSION: Emotional exhaustion of burnout syndrome, history of anxiety/depression, and a shorter professional experience were associated with vocal problems, which could limit the performance of teachers. Reducing classroom noise, establishing strategies to avoid shouting, or strengthening personal accomplishments in teachers could be useful in breaking the cycle of vocal problems and emotional exhaustion, particularly at the beginning of their professional experience.


Asunto(s)
Agotamiento Profesional , Pruebas Psicológicas , Autoinforme , Trastornos de la Voz , Humanos , España/epidemiología , Estudios Transversales , Encuestas y Cuestionarios , Agotamiento Profesional/epidemiología , Agotamiento Profesional/diagnóstico , Agotamiento Profesional/psicología , Trastornos de la Voz/epidemiología , Trastornos de la Voz/etiología , Agotamiento Emocional
8.
New Phytol ; 238(5): 1924-1941, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36918499

RESUMEN

An environmentally responsive root system is crucial for plant growth and crop yield, especially in suboptimal soil conditions. This responsiveness enables the plant to exploit regions of high nutrient density while simultaneously minimizing abiotic stress. Despite the vital importance of root systems in regulating plant growth, significant gaps of knowledge exist in the mechanisms that regulate their architecture. Auxin defines both the frequency of lateral root (LR) initiation and the rate of LR outgrowth. Here, we describe a search for proteins that regulate root system architecture (RSA) by interacting directly with a key auxin transporter, PIN1. The native separation of Arabidopsis plasma membrane protein complexes identified several PIN1 co-purifying proteins. Among them, AZG1 was subsequently confirmed as a PIN1 interactor. Here, we show that, in Arabidopsis, AZG1 is a cytokinin (CK) import protein that co-localizes with and stabilizes PIN1, linking auxin and CK transport streams. AZG1 expression in LR primordia is sensitive to NaCl, and the frequency of LRs is AZG1-dependent under salt stress. This report therefore identifies a potential point for auxin:cytokinin crosstalk, which shapes RSA in response to NaCl.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Citocininas , Proteínas de Transporte de Membrana , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Citocininas/metabolismo , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos/metabolismo , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Raíces de Plantas/metabolismo , Cloruro de Sodio
9.
MMWR Morb Mortal Wkly Rep ; 72(25): 683-689, 2023 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-37347715

RESUMEN

Although reinfections with SARS-CoV-2 have occurred in the United States with increasing frequency, U.S. epidemiologic trends in reinfections and associated severe outcomes have not been characterized. Weekly counts of SARS-CoV-2 reinfections, total infections, and associated hospitalizations and deaths reported by 18 U.S. jurisdictions during September 5, 2021-December 31, 2022, were analyzed overall, by age group, and by five periods of SARS-CoV-2 variant predominance (Delta and Omicron [BA.1, BA.2, BA.4/BA.5, and BQ.1/BQ.1.1]). Among reported reinfections, weekly trends in the median intervals between infections and frequencies of predominant variants during previous infections were calculated. As a percentage of all infections, reinfections increased substantially from the Delta (2.7%) to the Omicron BQ.1/BQ.1.1 (28.8%) periods; during the same periods, increases in the percentages of reinfections among COVID-19-associated hospitalizations (from 1.9% [Delta] to 17.0% [Omicron BQ.1/BQ.1.1]) and deaths (from 1.2% [Delta] to 12.3% [Omicron BQ.1/BQ.1.1]) were also substantial. Percentages of all COVID-19 cases, hospitalizations, and deaths that were reinfections were consistently higher across variant periods among adults aged 18-49 years compared with those among adults aged ≥50 years. The median interval between infections ranged from 269 to 411 days by week, with a steep decline at the start of the BA.4/BA.5 period, when >50% of reinfections occurred among persons previously infected during the Alpha variant period or later. To prevent severe COVID-19 outcomes, including those following reinfection, CDC recommends staying up to date with COVID-19 vaccination and receiving timely antiviral treatments, when eligible.


Asunto(s)
COVID-19 , SARS-CoV-2 , Adolescente , Adulto , Humanos , COVID-19/diagnóstico , COVID-19/epidemiología , Vacunas contra la COVID-19 , Hospitalización/tendencias , Reinfección/epidemiología , Mortalidad Hospitalaria
10.
J Water Health ; 21(9): 1303-1317, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37756197

RESUMEN

Monitoring for COVID-19 through wastewater has been used for adjunctive public health surveillance, with SARS-CoV-2 viral concentrations in wastewater correlating with incident cases in the same sewershed. However, the generalizability of these findings across sewersheds, laboratory methods, and time periods with changing variants and underlying population immunity has not been well described. The California Department of Public Health partnered with six wastewater treatment plants starting in January 2021 to monitor wastewater for SARS-CoV-2, with analyses performed at four laboratories. Using reported PCR-confirmed COVID-19 cases within each sewershed, the relationship between case incidence rates and wastewater concentrations collected over 14 months was evaluated using Spearman's correlation and linear regression. Strong correlations were observed when wastewater concentrations and incidence rates were averaged (10- and 7-day moving window for wastewater and cases, respectively, ρ = 0.73-0.98 for N1 gene target). Correlations remained strong across three time periods with distinct circulating variants and vaccination rates (winter 2020-2021/Alpha, summer 2021/Delta, and winter 2021-2022/Omicron). Linear regression revealed that slopes of associations varied by the dominant variant of concern, sewershed, and laboratory (ß = 0.45-1.94). These findings support wastewater surveillance as an adjunctive public health tool to monitor SARS-CoV-2 community trends.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , SARS-CoV-2 , Aguas Residuales , Incidencia , Monitoreo Epidemiológico Basado en Aguas Residuales , California/epidemiología
11.
BMC Public Health ; 23(1): 782, 2023 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-37118796

RESUMEN

BACKGROUND: The COVID-19 pandemic has highlighted the role of infectious disease forecasting in informing public policy. However, significant barriers remain for effectively linking infectious disease forecasts to public health decision making, including a lack of model validation. Forecasting model performance and accuracy should be evaluated retrospectively to understand under which conditions models were reliable and could be improved in the future. METHODS: Using archived forecasts from the California Department of Public Health's California COVID Assessment Tool ( https://calcat.covid19.ca.gov/cacovidmodels/ ), we compared how well different forecasting models predicted COVID-19 hospitalization census across California counties and regions during periods of Alpha, Delta, and Omicron variant predominance. RESULTS: Based on mean absolute error estimates, forecasting models had variable performance across counties and through time. When accounting for model availability across counties and dates, some individual models performed consistently better than the ensemble model, but model rankings still differed across counties. Local transmission trends, variant prevalence, and county population size were informative predictors for determining which model performed best for a given county based on a random forest classification analysis. Overall, the ensemble model performed worse in less populous counties, in part because of fewer model contributors in these locations. CONCLUSIONS: Ensemble model predictions could be improved by incorporating geographic heterogeneity in model coverage and performance. Consistency in model reporting and improved model validation can strengthen the role of infectious disease forecasting in real-time public health decision making.


Asunto(s)
COVID-19 , Enfermedades Transmisibles , Humanos , Pandemias , Estudios Retrospectivos , COVID-19/epidemiología , SARS-CoV-2 , Enfermedades Transmisibles/epidemiología , California/epidemiología , Política Pública , Toma de Decisiones , Hospitalización , Predicción
12.
Proc Natl Acad Sci U S A ; 117(25): 14503-14511, 2020 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-32513712

RESUMEN

The nanoscale co-organization of neurotransmitter receptors facing presynaptic release sites is a fundamental determinant of their coactivation and of synaptic physiology. At excitatory synapses, how endogenous AMPARs, NMDARs, and mGluRs are co-organized inside the synapse and their respective activation during glutamate release are still unclear. Combining single-molecule superresolution microscopy, electrophysiology, and modeling, we determined the average quantity of each glutamate receptor type, their nanoscale organization, and their respective activation. We observed that NMDARs form a unique cluster mainly at the center of the PSD, while AMPARs segregate in clusters surrounding the NMDARs. mGluR5 presents a different organization and is homogenously dispersed at the synaptic surface. From these results, we build a model predicting the synaptic transmission properties of a unitary synapse, allowing better understanding of synaptic physiology.


Asunto(s)
Modelos Neurológicos , Neuronas/metabolismo , Receptor del Glutamato Metabotropico 5/metabolismo , Receptores AMPA/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Transmisión Sináptica/fisiología , Animales , Células Cultivadas , Embrión de Mamíferos , Femenino , Ácido Glutámico/metabolismo , Hipocampo/citología , Hipocampo/diagnóstico por imagen , Hipocampo/fisiología , Microscopía Intravital , Neuronas/ultraestructura , Técnicas de Placa-Clamp , Cultivo Primario de Células , Ratas , Ratas Sprague-Dawley , Imagen Individual de Molécula
13.
Environ Manage ; 71(2): 350-364, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36520203

RESUMEN

Collaborative environmental management draws on a wide range of information, from a variety of stakeholders, to inform policy. Scientific information is particularly relevant for ecosystem restoration plans, such as those created for recovering species on the brink of extinction. This study examines use of evidence in salmon recovery plans in Puget Sound, USA. Across 12 plans, coders characterized 1104 references to identify their source, recency, domain, and context. Subsequently, 11 plans were analyzed in-depth to identify how each reference was used to support particular kinds of claims. Results indicate the most frequent source of information cited in salmon recovery plans is government agencies, especially from national and state governments, followed by peer reviewed journal articles and scientific books. Journal articles come predominantly from high impact (top quartile) journals, although these articles are on average 15 years old. Sources are almost exclusively from the domain of natural sciences (97%), with just 1% social sciences and 2% non-scientific. More references come from beyond than within the local watershed. Different reference sources are used to support different kinds of claims, with government agency sources positively associated with claims about species status/trends, and peer reviewed journal articles positively associated with claims about causes of species decline. Overall, the lack of social science references, and lack of references to support claims about levels of community support, reduce managers' abilities to incorporate features of social systems into species recovery planning.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Salmón , Animales , Agencias Gubernamentales , Humanos
14.
J Acad Mark Sci ; : 1-23, 2023 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-37359265

RESUMEN

Do stronger relationships with customers (customer-company relationships [CCR]) help firms better weather economic crises? To answer this question, we examine firm performance during the stock market crashes associated with the two most severe economic crises of the last 15 years-the protracted Great Recession crisis (2008-2009) and the shorter but extreme COVID-19 pandemic crisis (2020). Juxtaposing the predominant expected utility theory perspective with observed deviations in investor behavior during crises, we find that both pre-crash firm-level customer satisfaction and customer loyalty are positively associated with abnormal stock returns and lower idiosyncratic risk during a market crash, while pre-crash firm-level customer complaint rate negatively affects abnormal stock returns and increases idiosyncratic risk. On average, we find that one standard deviation higher CCR is associated with between $0.9 billion and $2.4 billion in market capitalization on an annualized basis. Importantly, we find that these effects are weaker for firms with higher market share during the COVID-19 crash, but not during the Great Recession crash. These results are found to be robust to a variety of alternate model specifications, time periods, sub-samples, accounting for firm strategies during the crises, and endogeneity corrections. When compared to relevant non-crash periods, we also find that such effects are equally strong during the Great Recession crash and even stronger during the COVID-19 pandemic crash. Contributing to both the marketing-finance interface literature and the nascent literature on marketing during economic crises, implications from these findings are provided for researchers, marketing theory, and managers. Supplementary information: The online version contains supplementary material available at 10.1007/s11747-023-00947-1.

15.
Antimicrob Agents Chemother ; 66(3): e0192321, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35041503

RESUMEN

The need for alternatives to antibiotic therapy due to the emergence of multidrug resistant bacteria (MDR), such as the nosocomial pathogen Acinetobacter baumannii, has led to the recovery of phage therapy. In addition, phages can be combined in cocktails to increase the host range. In this study, the evolutionary mechanism of adaptation was utilized in order to develop a phage adapted to A. baumannii, named phage Ab105-2phiΔCI404ad, from a mutant lytic phage, Ab105-2phiΔCI, previously developed by our group. The whole genome sequence of phage Ab105-2phiΔCI404ad was determined, showing that four genomic rearrangements events occurred in the tail morphogenesis module affecting the ORFs encoding the host receptor binding sites. As a consequence of the genomic rearrangements, 10 ORFs were lost and four new ORFs were obtained, all encoding tail proteins; two inverted regions were also derived from these events. The adaptation process increased the host range of the adapted phage by almost 3-fold. In addition, a depolymerase-expressing phenotype, indicated by formation of a halo, which was not observed in the ancestral phage, was obtained in 81% of the infected strains. A phage cocktail was formed by combining this phage with the A. baumannii phage vB_AbaP_B3, known to express a depolymerase. Both the individual phages and the phage cocktail showed strong antimicrobial activity against 5 clinical strains and 1 reference strain of A. baumannii tested. However, in all cases resistance to the bacterial strains was also observed. The antibiofilm activity of the individual phages and the cocktail was assayed. The phage cocktail displayed strong antibiofilm activity.


Asunto(s)
Infecciones por Acinetobacter , Acinetobacter baumannii , Bacteriófagos , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/genética , Bacteriófagos/genética , Biopelículas , Genoma Viral , Genómica , Humanos
16.
Chemistry ; 28(66): e202202333, 2022 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-36037397

RESUMEN

Electron harvesting bacteria are key targets to develop microbial electrosynthesis technologies, which are valid alternatives for the production of value-added compounds without utilization of fossil fuels. Geobacter sulfurreducens, that is capable of donating and accepting electrons from electrodes, is one of the most promising electroactive bacteria. Its electron transfer mechanisms to electrodes have been progressively elucidated, however the electron harvesting pathways are still poorly understood. Previous studies showed that the periplasmic cytochromes PccH and GSU2515 are overexpressed in current-consuming G. sulfurreducens biofilms. PccH was characterized, though no putative partners have been identified. In this work, GSU2515 was characterized by complementary biophysical techniques and in silico simulations using the AlphaFold neural network. GSU2515 is a low-spin monoheme cytochrome with a disordered N-terminal region and an α-helical C-terminal domain harboring the heme group. The cytochrome undergoes a redox-linked heme axial ligand switch, with Met91 and His94 as distal axial ligands in the reduced and oxidized states, respectively. The reduction potential of the cytochrome is negative and modulated by the pH in the physiological range: -78 mV at pH 6 and -113 mV at pH 7. Such pH-dependence coupled to the redox-linked switch of the axial ligand allows the cytochrome to drive a proton-coupled electron transfer step that is crucial to confer directionality to the respiratory chain. Biomolecular interactions and electron transfer experiments indicated that GSU2515 and PccH form a redox complex. Overall, the data obtained highlight for the first time how periplasmic proteins bridge the electron transfer between the outer and inner membrane in the electron harvesting pathways of G. sulfurreducens.


Asunto(s)
Proteínas Bacterianas , Electrones , Ligandos , Proteínas Bacterianas/metabolismo , Citocromos/química , Citocromos/metabolismo , Hemo/química , Transporte de Electrón , Oxidación-Reducción
17.
Arch Biochem Biophys ; 723: 109220, 2022 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-35430214

RESUMEN

Electroactive Geobacter bacteria can perform extracellular electron transfer and present a wide metabolic versatility. These bacteria reduce organic, toxic and radioactive compounds, and produce electric current while interacting with electrodes, making them interesting targets for numerous biotechnological applications. Their global electrochemical responses rely on an efficient interface between the inside and the cell's exterior, which is driven by the highly abundant periplasmic triheme PpcA-family cytochromes. The functional features of these cytochromes have been studied in G. sulfurreducens and G. metallireducens, and although they share a high degree of structural homology and sequence identity, their properties are quite distinct. In this work, the heme axial ligand geometries and the magnetic properties of PpcF from G. metallireducens were determined. The data obtained constitute important constraints for the determination of its solution structure in the oxidized state and indicate that the (i) heme core architecture; (ii) axial ligands geometries and (iii) magnetic properties of the cytochrome are conserved compared to the other members of the PpcA-families. Furthermore, the results also indicate that the heme arrangement is crucial to maintain an intrinsic regulation of the protein's redox properties and hence its electron transfer efficiency and functionality.


Asunto(s)
Geobacter , Proteínas Bacterianas/química , Citocromos/química , Hemo/metabolismo , Humanos , Ligandos , Oxidación-Reducción
18.
FASEB J ; 35(7): e21724, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34133802

RESUMEN

Neuromuscular junctions (NMJ) regulate cholinergic exocytosis through the M1 and M2 muscarinic acetylcholine autoreceptors (mAChR), involving the crosstalk between receptors and downstream pathways. Protein kinase C (PKC) regulates neurotransmission but how it associates with the mAChRs remains unknown. Here, we investigate whether mAChRs recruit the classical PKCßI and the novel PKCε isoforms and modulate their priming by PDK1, translocation and activity on neurosecretion targets. We show that each M1 and M2 mAChR activates the master kinase PDK1 and promotes a particular priming of the presynaptic PKCßI and ε isoforms. M1 recruits both primed-PKCs to the membrane and promotes Munc18-1, SNAP-25, and MARCKS phosphorylation. In contrast, M2 downregulates PKCε through a PKA-dependent pathway, which inhibits Munc18-1 synthesis and PKC phosphorylation. In summary, our results discover a co-dependent balance between muscarinic autoreceptors which orchestrates the presynaptic PKC and their action on ACh release SNARE-SM mechanism. Altogether, this molecular signaling explains previous functional studies at the NMJ and guide toward potential therapeutic targets.


Asunto(s)
Proteínas Quinasas Dependientes de 3-Fosfoinosítido/metabolismo , Unión Neuromuscular/metabolismo , Proteína Quinasa C/metabolismo , Receptores Muscarínicos/metabolismo , Acetilcolina/metabolismo , Animales , Regulación hacia Abajo/fisiología , Exocitosis/fisiología , Fosforilación/fisiología , Terminales Presinápticos/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción de Señal/fisiología , Transmisión Sináptica/fisiología , Proteína 25 Asociada a Sinaptosomas/metabolismo
19.
MMWR Morb Mortal Wkly Rep ; 71(4): 125-131, 2022 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-35085222

RESUMEN

By November 30, 2021, approximately 130,781 COVID-19-associated deaths, one in six of all U.S. deaths from COVID-19, had occurred in California and New York.* COVID-19 vaccination protects against infection with SARS-CoV-2 (the virus that causes COVID-19), associated severe illness, and death (1,2); among those who survive, previous SARS-CoV-2 infection also confers protection against severe outcomes in the event of reinfection (3,4). The relative magnitude and duration of infection- and vaccine-derived protection, alone and together, can guide public health planning and epidemic forecasting. To examine the impact of primary COVID-19 vaccination and previous SARS-CoV-2 infection on COVID-19 incidence and hospitalization rates, statewide testing, surveillance, and COVID-19 immunization data from California and New York (which account for 18% of the U.S. population) were analyzed. Four cohorts of adults aged ≥18 years were considered: persons who were 1) unvaccinated with no previous laboratory-confirmed COVID-19 diagnosis, 2) vaccinated (14 days after completion of a primary COVID-19 vaccination series) with no previous COVID-19 diagnosis, 3) unvaccinated with a previous COVID-19 diagnosis, and 4) vaccinated with a previous COVID-19 diagnosis. Age-adjusted hazard rates of incident laboratory-confirmed COVID-19 cases in both states were compared among cohorts, and in California, hospitalizations during May 30-November 20, 2021, were also compared. During the study period, COVID-19 incidence in both states was highest among unvaccinated persons without a previous COVID-19 diagnosis compared with that among the other three groups. During the week beginning May 30, 2021, compared with COVID-19 case rates among unvaccinated persons without a previous COVID-19 diagnosis, COVID-19 case rates were 19.9-fold (California) and 18.4-fold (New York) lower among vaccinated persons without a previous diagnosis; 7.2-fold (California) and 9.9-fold lower (New York) among unvaccinated persons with a previous COVID-19 diagnosis; and 9.6-fold (California) and 8.5-fold lower (New York) among vaccinated persons with a previous COVID-19 diagnosis. During the same period, compared with hospitalization rates among unvaccinated persons without a previous COVID-19 diagnosis, hospitalization rates in California followed a similar pattern. These relationships changed after the SARS-CoV-2 Delta variant became predominant (i.e., accounted for >50% of sequenced isolates) in late June and July. By the week beginning October 3, compared with COVID-19 cases rates among unvaccinated persons without a previous COVID-19 diagnosis, case rates among vaccinated persons without a previous COVID-19 diagnosis were 6.2-fold (California) and 4.5-fold (New York) lower; rates were substantially lower among both groups with previous COVID-19 diagnoses, including 29.0-fold (California) and 14.7-fold lower (New York) among unvaccinated persons with a previous diagnosis, and 32.5-fold (California) and 19.8-fold lower (New York) among vaccinated persons with a previous diagnosis of COVID-19. During the same period, compared with hospitalization rates among unvaccinated persons without a previous COVID-19 diagnosis, hospitalization rates in California followed a similar pattern. These results demonstrate that vaccination protects against COVID-19 and related hospitalization, and that surviving a previous infection protects against a reinfection and related hospitalization. Importantly, infection-derived protection was higher after the Delta variant became predominant, a time when vaccine-induced immunity for many persons declined because of immune evasion and immunologic waning (2,5,6). Similar cohort data accounting for booster doses needs to be assessed, as new variants, including Omicron, circulate. Although the epidemiology of COVID-19 might change with the emergence of new variants, vaccination remains the safest strategy to prevent SARS-CoV-2 infections and associated complications; all eligible persons should be up to date with COVID-19 vaccination. Additional recommendations for vaccine doses might be warranted in the future as the virus and immunity levels change.


Asunto(s)
Vacunas contra la COVID-19/administración & dosificación , COVID-19/epidemiología , COVID-19/prevención & control , Hospitalización/estadística & datos numéricos , SARS-CoV-2/inmunología , Vacunación/estadística & datos numéricos , Adulto , California/epidemiología , Estudios de Cohortes , Humanos , Incidencia , Persona de Mediana Edad , New York/epidemiología
20.
PLoS Comput Biol ; 17(5): e1009030, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-34019537

RESUMEN

Interest in gene drive technology has continued to grow as promising new drive systems have been developed in the lab and discussions are moving towards implementing field trials. The prospect of field trials requires models that incorporate a significant degree of ecological detail, including parameters that change over time in response to environmental data such as temperature and rainfall, leading to seasonal patterns in mosquito population density. Epidemiological outcomes are also of growing importance, as: i) the suitability of a gene drive construct for release will depend on its expected impact on disease transmission, and ii) initial field trials are expected to have a measured entomological outcome and a modeled epidemiological outcome. We present MGDrivE 2 (Mosquito Gene Drive Explorer 2): a significant development from the MGDrivE 1 simulation framework that investigates the population dynamics of a variety of gene drive architectures and their spread through spatially-explicit mosquito populations. Key strengths and fundamental improvements of the MGDrivE 2 framework are: i) the ability of parameters to vary with time and induce seasonal population dynamics, ii) an epidemiological module accommodating reciprocal pathogen transmission between humans and mosquitoes, and iii) an implementation framework based on stochastic Petri nets that enables efficient model formulation and flexible implementation. Example MGDrivE 2 simulations are presented to demonstrate the application of the framework to a CRISPR-based split gene drive system intended to drive a disease-refractory gene into a population in a confinable and reversible manner, incorporating time-varying temperature and rainfall data. The simulations also evaluate impact on human disease incidence and prevalence. Further documentation and use examples are provided in vignettes at the project's CRAN repository. MGDrivE 2 is freely available as an open-source R package on CRAN (https://CRAN.R-project.org/package=MGDrivE2). We intend the package to provide a flexible tool capable of modeling gene drive constructs as they move closer to field application and to infer their expected impact on disease transmission.


Asunto(s)
Tecnología de Genética Dirigida , Mosquitos Vectores , Estaciones del Año , Enfermedades Transmitidas por Vectores/epidemiología , Animales , Humanos , Enfermedades Transmitidas por Vectores/genética , Enfermedades Transmitidas por Vectores/transmisión
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