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1.
Cell ; 153(5): 1000-11, 2013 May 23.
Article in English | MEDLINE | ID: mdl-23706738

ABSTRACT

Maintaining proper mRNA levels is a key aspect in the regulation of gene expression. The balance between mRNA synthesis and decay determines these levels. We demonstrate that most yeast mRNAs are degraded by the cytoplasmic 5'-to-3' pathway (the "decaysome"), as proposed previously. Unexpectedly, the level of these mRNAs is highly robust to perturbations in this major pathway because defects in various decaysome components lead to transcription downregulation. Moreover, these components shuttle between the cytoplasm and the nucleus, in a manner dependent on proper mRNA degradation. In the nucleus, they associate with chromatin-preferentially ∼30 bp upstream of transcription start-sites-and directly stimulate transcription initiation and elongation. The nuclear role of the decaysome in transcription is linked to its cytoplasmic role in mRNA decay; linkage, in turn, seems to depend on proper shuttling of its components. The gene expression process is therefore circular, whereby the hitherto first and last stages are interconnected.


Subject(s)
Gene Expression Regulation, Fungal , RNA Stability , RNA, Fungal/metabolism , RNA, Messenger/metabolism , Saccharomyces cerevisiae/metabolism , Transcription, Genetic , Cell Nucleus/metabolism , Cytoplasm/metabolism , Exoribonucleases/metabolism , Genes, Fungal/genetics , RNA Polymerase II/metabolism , RNA, Fungal/genetics , RNA, Messenger/genetics , RNA-Binding Proteins/metabolism , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/metabolism
2.
BMC Neurol ; 24(1): 108, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38566012

ABSTRACT

BACKGROUND: Effective interventions for Multiple Sclerosis require timely treatment optimization which usually involves switching disease modifying therapies. The patterns of prescription and the reasons for changing treatment in people with MS, especially in low prevalence populations, are unknown. OBJECTIVES: To describe the persistence, reasons of DMT switches and prescription patterns in a cohort of Colombian people with MS. METHODS: We conducted a retrospective observational study including patients with confirmed MS with at least one visit at our centre. We estimated the overall incidence rate of medication changes and assessed the persistence on medication with Kaplan-Meier survival estimates for individual medications and according to efficacy and mode of administration. The factors associated with changing medications were assessed using adjusted Cox proportional-hazards models. The reasons for switching medication changes were described, and the prescription patterns were assessed using network analysis, with measures of centrality. RESULTS: Seven hundred one patients with MS were included. Mean age was 44.3 years, and 67.9% were female. Mean disease duration was 11.3 years and 84.5% had relapsing MS at onset, with median EDSS of 1.0. Treatment was started in 659 (94%) of the patients after a mean of 3 years after MS symptom onset. Among them, 39.5% maintained their initial DMT, 29.9% experienced a single DMT change, while 18.7% went through two, and 11.9% had three or more DMT changes until the final follow-up. The total number of treatment modifications reached 720, resulting in an incidence rate of 1.09 (95% confidence interval: 1.01-1.17) per patient per year The median time to change after the first DMT was 3.75 years, and was not different according to the mode of administration or efficacy classification. The main reasons for changing DMT were MS activity (relapses, 56.7%; MRI activity, 18.6%), followed by non-serious adverse events (15.3%) and disability (11.1%). Younger age at MS onset, care under our centre and insurer status were the main determinants of treatment change. Network analysis showed that interferons and fingolimod were the most influential DMTs. CONCLUSIONS: A majority of patients switch medications, mostly due to disease activity, and in association with age and insurer status.


Subject(s)
Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , South American People , Humans , Female , Adult , Male , Multiple Sclerosis/drug therapy , Multiple Sclerosis/epidemiology , Fingolimod Hydrochloride/therapeutic use , Retrospective Studies , Proportional Hazards Models , Multiple Sclerosis, Relapsing-Remitting/drug therapy
3.
Neurol Sci ; 45(1): 55-63, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37697027

ABSTRACT

After a stroke, several mechanisms of neural plasticity can be activated, which may lead to significant recovery. Rehabilitation therapies aim to restore surviving tissue over time and reorganize neural connections. With more patients surviving stroke with varying degrees of neurological impairment, new technologies have emerged as a promising option for better functional outcomes. This review explores restorative therapies based on brain-computer interfaces, robot-assisted and virtual reality, brain stimulation, and cell therapies. Brain-computer interfaces allow for the translation of brain signals into motor patterns. Robot-assisted and virtual reality therapies provide interactive interfaces that simulate real-life situations and physical support to compensate for lost motor function. Brain stimulation can modify the electrical activity of neurons in the affected cortex. Cell therapy may promote regeneration in damaged brain tissue. Taken together, these new approaches could substantially benefit specific deficits such as arm-motor control and cognitive impairment after stroke, and even the chronic phase of recovery, where traditional rehabilitation methods may be limited, and the window for repair is narrow.


Subject(s)
Stroke Rehabilitation , Stroke , Humans , Stroke/therapy , Brain , Neuronal Plasticity/physiology , Cerebral Cortex , Recovery of Function
4.
Cancer Immunol Immunother ; 72(6): 1405-1415, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36445410

ABSTRACT

BACKGROUND: CAPRA (NCT02565992) evaluated Coxsackievirus A21 (V937) + pembrolizumab for metastatic/unresectable stage IIIB-IV melanoma. METHODS: Patients received intratumoral V937 on days 1, 3, 5, and 8 (then every 3 weeks [Q3W]) and intravenous pembrolizumab 2 mg/kg Q3W from day 8. Primary endpoint was safety. RESULTS: Median time from first dose to data cutoff was 32.0 months. No dose-limiting toxicities occurred; 14% (5/36) of patients experienced grade 3‒5 treatment-related adverse events. Objective response rate was 47% (complete response, 22%). Among 17 responders, 14 (82%) had responses ≥ 6 months. Among 8 patients previously treated with immunotherapy, 3 responded (1 complete, 2 partial). Responses were associated with increased serum CXCL10 and CCL22, suggesting viral replication contributes to antitumor immunity. For responders versus nonresponders, there was no difference in baseline tumor PD-L1 expression, ICAM1 expression, or CD3+ infiltrates. Surprisingly, the baseline cell density of CD3+CD8- T cells in the tumor microenvironment was significantly lower in responders compared with nonresponders (P = 0.0179). CONCLUSIONS: These findings suggest responses to this combination may be seen even in patients without a typical "immune-active" microenvironment. TRIAL REGISTRATION NUMBER: NCT02565992.


Subject(s)
Melanoma , Oncolytic Viruses , Humans , Animals , Goats , Antibodies, Monoclonal, Humanized/adverse effects , Melanoma/drug therapy , Tumor Microenvironment
5.
RNA ; 27(10): 1281-1290, 2021 10.
Article in English | MEDLINE | ID: mdl-34272303

ABSTRACT

Gene expression in eukaryotes does not follow a linear process from transcription to translation and mRNA degradation. Instead it follows a circular process in which cytoplasmic mRNA decay crosstalks with nuclear transcription. In many instances, this crosstalk contributes to buffer mRNA at a roughly constant concentration. Whether the mRNA buffering concept operates on the total mRNA concentration or at the gene-specific level, and if the mechanism to do so is a global or a specific one, remain unknown. Here we assessed changes in mRNA concentrations and their synthesis rates along the transcriptome of aneuploid strains of the yeast Saccharomyces cerevisiae We also assessed mRNA concentrations and their synthesis rates in nonsense-mediated decay (NMD) targets in euploid strains. We found that the altered synthesis rates in the genes from the aneuploid chromosome and the changes in their mRNA stabilities were not counterbalanced. In addition, the stability of NMD targets was not specifically compensated by the changes in synthesis rate. We conclude that there is no genetic compensation of NMD mRNA targets in yeast, and total mRNA buffering uses mostly a global system rather than a gene-specific one.


Subject(s)
Gene Expression Regulation, Fungal , Genome, Fungal , RNA, Fungal/genetics , RNA, Messenger/genetics , Saccharomyces cerevisiae/genetics , Aneuploidy , Codon, Nonsense , Nonsense Mediated mRNA Decay , RNA, Fungal/metabolism , RNA, Messenger/metabolism , Saccharomyces cerevisiae/metabolism , Transcriptome
6.
J Neurovirol ; 29(2): 237-240, 2023 04.
Article in English | MEDLINE | ID: mdl-36867345

ABSTRACT

A new outbreak of monkeypox has been reported worldwide with CNS complications like encephalitis or myelitis being extremely rare. We present a case of a 30-year-old man with PCR-confirmed diagnosis of monkeypox who developed rapid neurological deterioration with extensive inflammatory involvement of the brain and spinal cord on MRI. Because of the clinical and radiological resemblance to acute disseminated encephalomyelitis (ADEM), it was decided to indicate treatment with high-dose corticosteroids for 5 days (without concomitant antiviral management due to lack of availability in our country). Given the poor clinical and radiological response, 5 days of immunoglobulin G were administered. During follow-up the patient's clinical condition improved, physiotherapy was started and all associated medical complications were controlled. To our knowledge, this is the first reported monkeypox case with severe CNS complications treated with steroids and immunoglobulin in the absence of specific antiviral treatment.


Subject(s)
Encephalomyelitis, Acute Disseminated , Encephalomyelitis , Mpox (monkeypox) , Male , Humans , Adult , Mpox (monkeypox)/complications , Mpox (monkeypox)/drug therapy , Encephalomyelitis, Acute Disseminated/complications , Encephalomyelitis, Acute Disseminated/diagnostic imaging , Encephalomyelitis, Acute Disseminated/drug therapy , Brain/diagnostic imaging , Magnetic Resonance Imaging , Antiviral Agents/therapeutic use , Encephalomyelitis/diagnostic imaging , Encephalomyelitis/drug therapy , Encephalomyelitis/complications
7.
Am J Hematol ; 98(8): 1204-1213, 2023 08.
Article in English | MEDLINE | ID: mdl-37151135

ABSTRACT

Data on the effect of booster SARS-CoV-2 vaccination are mainly focused on humoral immunogenicity, while the kinetics of vaccine-induced cellular response and its correlation with effectiveness in hematologic patients are less explored. Our aim was to evaluate the longitudinal cellular and humoral immunogenicity induced by two and three doses of the mRNA-1273 SARS-CoV-2 vaccine in 270 patients with hematologic malignancies, and its relationship with the severity of breakthrough SARS-CoV-2 infection. Results indicate that at 23 weeks after the second dose, the seroconversion rate declined from 68.5% to 59.3%, with a reduction in median anti-S titers from 1577 to 456 BAU/mL, mainly in patients over 65 years of age or chronic lymphocytic leukemia (CLL) patients undergoing active therapy. Cellular immunogenicity, however, remained positive in 84.4% of cases. A third vaccine dose seroconverted 42.7% (41/96) and triggered cellular response in 36.7% (11/30) of previously negative patients. Notably, only 7.2% (15/209) of patients failed to develop both humoral and cellular response. Active therapy, anti-CD20 antibodies, lymphopenia, hypogammaglobulinemia, and low CD19+ cell count were associated with poor humoral response, while active disease, GvHD immunosuppressive therapy, lymphopenia, and low CD3+ , CD4+ , CD56+ cell count determined an impaired cellular response. After 13.8 months of follow-up, the incidence of SARS-CoV-2 infection was 24.8% (67/270), including 6 (9%) severe/critical cases associated with a weaker cellular (median interferon gamma (IFN-γ) 0.19 vs. 0.35 IU/mL) and humoral response (median anti-S titer <4.81 vs. 788 BAU/mL) than asymptomatic/mild cases. In conclusion, SARS-CoV-2 booster vaccination improves humoral response and COVID-19 severity is associated with impaired vaccine-induced immunogenicity.


Subject(s)
COVID-19 , Hematologic Neoplasms , Lymphopenia , Humans , COVID-19 Vaccines , SARS-CoV-2 , COVID-19/prevention & control , Vaccination , Hematologic Neoplasms/therapy , Antibodies , Antibodies, Viral
8.
Epilepsy Behav ; 146: 109383, 2023 09.
Article in English | MEDLINE | ID: mdl-37549466

ABSTRACT

INTRODUCTION: Adverse drug reactions (ADRs) to antiseizure therapy can worsen the quality of life, reduce adherence, and potentially lead to treatment discontinuation and uncontrolled seizures. OBJECTIVES: The aim of the study was to develop a prognostic model for ADRs to antiseizure therapy in adult patients with epilepsy from Colombia. METHODS: This case-control study included adult patients with epilepsy, who were separated into two groups: one group with ADRs to antiseizure therapy (cases), as determined by a complete evaluation conducted by an epileptologist, and another group without ADRs (controls). Variables were analyzed to identify statistical differences between the two groups and were then selected to construct a prognostic model using logistic regression. The Bonferroni method was applied for multiple comparisons. RESULTS: Three hundred fifty-four patients with epilepsy were studied. One hundred and fifty (42%) patients had ADRs and 204 (57%) patients did not have ADs. A total of 362 ADRs were reported, with a third of them being general symptoms and most frequently occurring with older-generation antiseizure drugs (58%). Female sex, drug-resistant epilepsy, LEV, and CZP were risk factors, whereras the presence of tumoral etiology, absence of seizure triggers, and VPA were identified as protective factors. A prognostic model was constructed using previously reported risk factors for ADRs to antiseizure therapy and other variables available in this population study. In the multivariable analysis, the number of previously used antiseizure drugs (1, 2, or ≥3), TPM, CZP, LEV, PHT, and female sex were predictors of ADRs. The corrected p-values were estimated by the Bonferroni method; however, not all the variables achieved statistical significance with this adjustment. CONCLUSIONS: In adult patients with epilepsy from Colombia, we found that the number of previously used antiseizure drugs, TPM, CZP, LEV, PHT, and female sex were predictive factors for ADRs to antiseizure therapy.


Subject(s)
Drug-Related Side Effects and Adverse Reactions , Epilepsy , Humans , Adult , Female , Anticonvulsants/adverse effects , Case-Control Studies , Colombia/epidemiology , Quality of Life , Epilepsy/drug therapy , Epilepsy/chemically induced , Seizures/drug therapy , Seizures/chemically induced , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/drug therapy
9.
Proc Natl Acad Sci U S A ; 117(2): 1119-1128, 2020 01 14.
Article in English | MEDLINE | ID: mdl-31888983

ABSTRACT

Reprogramming the tumor microenvironment to increase immune-mediated responses is currently of intense interest. Patients with immune-infiltrated "hot" tumors demonstrate higher treatment response rates and improved survival. However, only the minority of tumors are hot, and a limited proportion of patients benefit from immunotherapies. Innovative approaches that make tumors hot can have immediate impact particularly if they repurpose drugs with additional cancer-unrelated benefits. The seasonal influenza vaccine is recommended for all persons over 6 mo without prohibitive contraindications, including most cancer patients. Here, we report that unadjuvanted seasonal influenza vaccination via intratumoral, but not intramuscular, injection converts "cold" tumors to hot, generates systemic CD8+ T cell-mediated antitumor immunity, and sensitizes resistant tumors to checkpoint blockade. Importantly, intratumoral vaccination also provides protection against subsequent active influenza virus lung infection. Surprisingly, a squalene-based adjuvanted vaccine maintains intratumoral regulatory B cells and fails to improve antitumor responses, even while protecting against active influenza virus lung infection. Adjuvant removal, B cell depletion, or IL-10 blockade recovers its antitumor effectiveness. Our findings propose that antipathogen vaccines may be utilized for both infection prevention and repurposing as a cancer immunotherapy.


Subject(s)
Immunotherapy/methods , Influenza Vaccines/administration & dosage , Influenza Vaccines/immunology , Influenza Vaccines/therapeutic use , Injections, Intralesional , Neoplasms/drug therapy , Neoplasms/immunology , Adjuvants, Immunologic/administration & dosage , Animals , B-Lymphocytes , Basic-Leucine Zipper Transcription Factors/genetics , CD8-Positive T-Lymphocytes/immunology , Humans , Immunity, Cellular , Influenza A Virus, H1N1 Subtype/immunology , Influenza, Human , Interleukin-10 , Lung/pathology , Lung Neoplasms/drug therapy , Lung Neoplasms/immunology , Lung Neoplasms/pathology , Mice , Mice, Inbred C57BL , Repressor Proteins/genetics , Seasons , Skin , Skin Neoplasms/drug therapy , Skin Neoplasms/pathology , Squalene/administration & dosage , Tumor Microenvironment/drug effects , Vaccination
10.
Proc Biol Sci ; 289(1978): 20220586, 2022 07 13.
Article in English | MEDLINE | ID: mdl-35858072

ABSTRACT

Many endangered amphibian species survive in captive breeding facilities, but there have been few attempts to reintroduce captive-born individuals to rebuild wild populations. We conducted a soft-release trial of limosa harlequin frogs, Atelopus limosus, which are highly susceptible to the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), to understand changes associated with the transition from captivity to the wild. Specifically, we assessed changes in body condition, skin-associated bacterial communities and disease status after release. Frogs were housed individually in field mesocosms and monitored for 27 days. Body condition did not significantly change in the mesocosms, and was similar to, or higher than, that of wild conspecifics at day 27. The skin bacteria of captive-born frogs, based on 16S rRNA gene amplicons, became similar to that of wild conspecifics after 27 days in mesocosms. Prevalence of Bd in wild conspecifics was 13-27%, and 15% of the A. limosus in mesocosms became infected with Bd, but no mortality of infected frogs was observed. We conclude that mesocosms are suitable for systematically and repeatedly monitoring amphibians during release trials, and that body condition, the skin microbiome, and Bd status can all change within one month of placement of captive-born individuals back into the wild.


Subject(s)
Chytridiomycota , Mycoses , Animals , Anura/genetics , Bacteria , Bufonidae/genetics , Chytridiomycota/genetics , Mycoses/microbiology , Mycoses/veterinary , Plant Breeding , RNA, Ribosomal, 16S/genetics , Skin/microbiology
11.
12.
Antonie Van Leeuwenhoek ; 114(9): 1323-1336, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34052985

ABSTRACT

Several members of the Mycobacterium genus cause invasive infections in humans and animals. According to a recent phylogenetic analysis, some strains of Mycobacterium salmoniphilum (Msal), which are the main culprit in bacterial outbreaks in freshwater fish aquaculture, have been assigned to a separate branch containing Mycobacterium franklinii (Mfra), another species that causes infections in humans. However, this genus is little studied in an aquaculture context. Here, we isolated four Mycobacterium spp. strains from freshwater cultures of Atlantic and coho salmon in Chile and performed whole-genome sequencing for deep genomic characterization. In addition, we described the gross pathology and histopathology of the outbreaks. Several bioinformatic analyses were performed using the genomes of these four Mycobacterium isolates in conjunction with those of Msal strains, four Msal-like strains, and one Mfra strains, plus 17 other publicly available Mycobacterium genomes. We found that three isolates are clustered into the Msal branch, whereas one isolate clustered with the Mfra/Msal-like strains. We further evaluated the presence of virulence and antimicrobial resistance genes and observed that the four isolates were closely related to the Msal and Msal-like taxa and carried several antimicrobial resistance and virulence genes that are similar to those of other pathogenic members of the Mycobacterium clade. Altogether, our characterization Msal and Msal-like presented here shed new light on the basis of mycobacteriosis provides quantitative evidence that Mycobacterium strains are a potential risk for aquaculture asetiological agents of emerging diseases, and highlight their biological scopes in the aquaculture industry.


Subject(s)
Fish Diseases , Mycobacterium , Oncorhynchus kisutch , Animals , Chile , Genomics , Humans , Mycobacteriaceae , Mycobacterium/genetics , Phylogeny
13.
Dis Aquat Organ ; 145: 79-88, 2021 Jun 17.
Article in English | MEDLINE | ID: mdl-34137378

ABSTRACT

Chytridiomycosis, an emergent infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), is considered one of the drivers of the current amphibian biodiversity loss. To inform endangered species conservation efforts, it is essential to improve our knowledge about the abiotic and biotic factors that influence Bd infection dynamics in the wild. Here, we analyzed variation of Bd infection in the redbelly toad Melanophryniscus montevidensis, a threatened bufonid from Uruguay. We tested the influence of temperature, precipitation, season, and host population size on Bd prevalence and intensity. Additionally, considering the sub-lethal effects of Bd, we tested if these variables, potentially through their effect on Bd, also explain the variation in host body condition. We determined a high Bd prevalence of 41% (100/241), and that population size influenced both Bd prevalence and infection intensity. We identified an effect of precipitation and season on Bd infection intensity and an effect of season on toad body condition. In addition, we found a negative effect of infection intensity on body condition; moreover, while some toads cleared the infection, their body condition did not improve, suggesting a long-term cost. This is the first report on host population size as an important factor in Bd infection dynamics in a threatened anuran species, and seasonal demographic changes appear to play an important role in the dynamics. Finally, we highlight the need for monitoring Bd in this and other endangered amphibian populations, especially those within the genus Melanophryniscus, which includes several Endangered and Data Deficient species in South America.


Subject(s)
Chytridiomycota , Animals , Batrachochytrium , Bufonidae , Endangered Species , Seasons , South America , Uruguay/epidemiology
14.
Br J Sports Med ; 55(8): 416, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33097528

ABSTRACT

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.


Subject(s)
Athletic Performance/physiology , Diet, Healthy , Nutrition Policy , Soccer/physiology , Athletic Injuries/rehabilitation , Body Composition , Competitive Behavior/physiology , Cultural Diversity , Dietary Supplements , Environment , Female , Humans , Male , Nutritional Requirements , Physical Conditioning, Human/physiology , Travel
15.
Sensors (Basel) ; 21(4)2021 Feb 10.
Article in English | MEDLINE | ID: mdl-33578725

ABSTRACT

Global navigation satellite systems (GNSSs) play a key role in intelligent transportation systems such as autonomous driving or unmanned systems navigation. In such applications, it is fundamental to ensure a reliable precise positioning solution able to operate in harsh propagation conditions such as urban environments and under multipath and other disturbances. Exploiting carrier phase observations allows for precise positioning solutions at the complexity cost of resolving integer phase ambiguities, a procedure that is particularly affected by non-nominal conditions. This limits the applicability of conventional filtering techniques in challenging scenarios, and new robust solutions must be accounted for. This contribution deals with real-time kinematic (RTK) positioning and the design of robust filtering solutions for the associated mixed integer- and real-valued estimation problem. Families of Kalman filter (KF) approaches based on robust statistics and variational inference are explored, such as the generalized M-based KF or the variational-based KF, aiming to mitigate the impact of outliers or non-nominal measurement behaviors. The performance assessment under harsh propagation conditions is realized using a simulated scenario and real data from a measurement campaign. The proposed robust filtering solutions are shown to offer excellent resilience against outlying observations, with the variational-based KF showcasing the overall best performance in terms of Gaussian efficiency and robustness.

16.
Scand J Immunol ; 91(4): e12862, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31889332

ABSTRACT

CRISPR/Cas9 is a powerful gene-editing tool allowing for specific gene manipulation at targeted sites in the genome. Here, we used CRISPR/Cas9-mediated gene editing to introduce single amino acid mutations into proteins involved in T cell receptor signalling pathways. Knock-in mutations were introduced in Jurkat T cells by homologous directed repair using single-stranded oligodeoxynucleotides. Specifically, we aimed to create targeted mutations at two loci within LCK, a constitutively expressed gene, and at three loci within SH2D2A, whose expression is induced upon T cell activation. Here, we present a simple workflow that can be applied by any laboratory equipped for cell culture work, utilizing basic flow cytometry, Western blotting and PCR techniques. Our data reveal that gene editing may be locus-dependent and can vary between target sites, also within a gene. In our two targeted genes, on average 2% of the clones harboured homozygous mutations as assessed by allele-specific PCR and subsequent sequencing. We highlight the importance of decreasing the clonal heterogeneity and developing robust screening methods to accurately select for correct knock-in mutations. Our workflow may be employed in other immune cell lines and acts as a useful approach for decoding functional mechanisms of proteins of interest.


Subject(s)
CRISPR-Cas Systems , Gene Editing/methods , Gene Knock-In Techniques/methods , T-Lymphocytes , Workflow , Humans , Jurkat Cells , Mutation
17.
Sensors (Basel) ; 20(12)2020 Jun 25.
Article in English | MEDLINE | ID: mdl-32630365

ABSTRACT

Global Navigation Satellite Systems (GNSS) are the main source of position, navigation, and timing (PNT) information and will be a key player in the next-generation intelligent transportation systems and safety-critical applications, but several limitations need to be overcome to meet the stringent performance requirements. One of the open issues is how to provide precise PNT solutions in harsh propagation environments. Under nominal conditions, the former is typically achieved by exploiting carrier phase information through precise positioning techniques, but these methods are very sensitive to the quality of phase observables. Another option that is gaining interest in the scientific community is the use of large bandwidth signals, which allow obtaining a better baseband resolution, and therefore more precise code-based observables. Two options may be considered: (i) high-order binary offset carrier (HO-BOC) modulations or (ii) the concept of GNSS meta-signals. In this contribution, we assess the time-delay and phase maximum likelihood (ML) estimation performance limits of such signals, together with the performance translation into the position domain, considering single point positioning (SPP) and RTK solutions, being an important missing point in the literature. A comprehensive discussion is provided on the estimators' behavior, the corresponding ML threshold regions, the impact of good and bad satellite constellation geometries, and final conclusions on the best candidates, which may lead to precise solutions under harsh conditions. It is found that if the receiver is constrained by the receiver bandwidth, the best choices are the L1-M or E6-Public Regulated Service (PRS) signals. If the receiver is able to operate at 60 MHz, it is recommended to exploit the full-bandwidth Galileo E5 signal. In terms of robustness and performance, if the receiver can operate at 135 MHz, the best choice is to use the GNSS meta-signals E5 + E6 or B2 + B3, which provide the best overall performances regardless of the positioning method used, the satellite constellation geometry, or the propagation conditions.

18.
Environ Microbiol ; 21(8): 2905-2920, 2019 08.
Article in English | MEDLINE | ID: mdl-31087743

ABSTRACT

Amphibian population declines caused by the fungus Batrachochytrium dendrobatidis (Bd) have prompted studies on the bacterial community that resides on amphibian skin. However, studies addressing the fungal portion of these symbiont communities have lagged behind. Using ITS1 amplicon sequencing, we examined the fungal portion of the skin microbiome of temperate and tropical amphibian species currently coexisting with Bd in nature. We assessed cooccurrence patterns between bacterial and fungal OTUs using a subset of samples for which bacterial 16S rRNA gene amplicon data were also available. We determined that fungal communities were dominated by members of the phyla Ascomycota and Basidiomycota, and also by Chytridiomycota in the most aquatic amphibian species. Alpha diversity of the fungal communities differed across host species, and fungal community structure differed across species and regions. However, we did not find a correlation between fungal diversity/community structure and Bd infection, though we did identify significant correlations between Bd and specific OTUs. Moreover, positive bacterial-fungal cooccurrences suggest that positive interactions between these organisms occur in the skin microbiome. Understanding the ecology of amphibian skin fungi, and their interactions with bacteria will complement our knowledge of the factors influencing community assembly and the overall function of these symbiont communities.


Subject(s)
Anura/microbiology , Chytridiomycota , Mycobiome , Mycoses/veterinary , Animals , Chytridiomycota/genetics , Fungi/classification , Fungi/isolation & purification , Host Specificity , Microbiota , Molecular Typing , Mycoses/microbiology , Skin/microbiology , Symbiosis
19.
Nucleic Acids Res ; 45(21): 12401-12412, 2017 Dec 01.
Article in English | MEDLINE | ID: mdl-29069448

ABSTRACT

Most cells divide symmetrically into two approximately identical cells. There are many examples, however, of asymmetric cell division that can generate sibling cell size differences. Whereas physical asymmetric division mechanisms and cell fate consequences have been investigated, the specific problem caused by asymmetric division at the transcription level has not yet been addressed. In symmetrically dividing cells the nascent transcription rate increases in parallel to cell volume to compensate it by keeping the actual mRNA synthesis rate constant. This cannot apply to the yeast Saccharomyces cerevisiae, where this mechanism would provoke a never-ending increasing mRNA synthesis rate in smaller daughter cells. We show here that, contrarily to other eukaryotes with symmetric division, budding yeast keeps the nascent transcription rates of its RNA polymerases constant and increases mRNA stability. This control on RNA pol II-dependent transcription rate is obtained by controlling the cellular concentration of this enzyme.


Subject(s)
Cell Division/genetics , RNA Stability , RNA, Messenger/metabolism , Transcription, Genetic , Cell Cycle/genetics , Cell Size , DNA-Directed RNA Polymerases/metabolism , RNA Polymerase I/metabolism , RNA, Messenger/biosynthesis , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/metabolism
20.
Br J Sports Med ; 53(19): 1214-1220, 2019 Oct.
Article in English | MEDLINE | ID: mdl-29674346

ABSTRACT

A better understanding of how sports injuries occur in order to improve their prevention is needed for medical, economic, scientific and sports success reasons. This narrative review aims to explain the mechanisms that underlie the occurrence of sports injuries, and an innovative approach for their prevention on the basis of complex dynamic systems approach. First, we explain the multilevel organisation of living systems and how function of the musculoskeletal system may be impaired. Second, we use both, a constraints approach and a connectivity hypothesis to explain why and how the susceptibility to sports injuries may suddenly increase. Constraints acting at multiple levels and timescales replace the static and linear concept of risk factors, and the connectivity hypothesis brings an understanding of how the accumulation of microinjuries creates a macroscopic non-linear effect, that is, how a common motor action may trigger a severe injury. Finally, a recap of practical examples and challenges for the future illustrates how the complex dynamic systems standpoint, changing the way of thinking about sports injuries, offers innovative ideas for improving sports injury prevention.


Subject(s)
Athletic Injuries/epidemiology , Athletic Injuries/prevention & control , Systems Analysis , Humans , Musculoskeletal System/injuries , Risk Factors , Sports Medicine , Workload
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