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1.
mSystems ; : e0031424, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940520

RESUMO

We use metagenome-assembled genomes (MAGs) to understand single-carbon (C1) compound-cycling-particularly methane-cycling-microorganisms in montane riparian floodplain sediments. We generated 1,233 MAGs (>50% completeness and <10% contamination) from 50- to 150-cm depth below the sediment surface capturing the transition between oxic, unsaturated sediments and anoxic, saturated sediments in the Slate River (SR) floodplain (Crested Butte, CO, USA). We recovered genomes of putative methanogens, methanotrophs, and methylotrophs (n = 57). Methanogens, found only in deep, anoxic depths at SR, originate from three different clades (Methanoregulaceae, Methanotrichaceae, and Methanomassiliicoccales), each with a different methanogenesis pathway; putative methanotrophic MAGs originate from within the Archaea (Candidatus Methanoperedens) in anoxic depths and uncultured bacteria (Ca. Binatia) in oxic depths. Genomes for canonical aerobic methanotrophs were not recovered. Ca. Methanoperedens were exceptionally abundant (~1,400× coverage, >50% abundance in the MAG library) in one sample that also contained aceticlastic methanogens, indicating a potential C1/methane-cycling hotspot. Ca. Methylomirabilis MAGs from SR encode pathways for methylotrophy but do not harbor methane monooxygenase or nitrogen reduction genes. Comparative genomic analysis supports that one clade within the Ca. Methylomirabilis genus is not methanotrophic. The genetic potential for methylotrophy was widespread, with over 10% and 19% of SR MAGs encoding a methanol dehydrogenase or substrate-specific methyltransferase, respectively. MAGs from uncultured Thermoplasmata archaea in the Ca. Gimiplasmatales (UBA10834) contain pathways that may allow for anaerobic methylotrophic acetogenesis. Overall, MAGs from SR floodplain sediments reveal a potential for methane production and consumption in the system and a robust potential for methylotrophy.IMPORTANCEThe cycling of carbon by microorganisms in subsurface environments is of particular relevance in the face of global climate change. Riparian floodplain sediments contain high organic carbon that can be degraded into C1 compounds such as methane, methanol, and methylamines, the fate of which depends on the microbial metabolisms present as well as the hydrological conditions and availability of oxygen. In the present study, we generated over 1,000 MAGs from subsurface sediments from a montane river floodplain and recovered genomes for microorganisms that are capable of producing and consuming methane and other C1 compounds, highlighting a robust potential for C1 cycling in subsurface sediments both with and without oxygen. Archaea from the Ca. Methanoperedens genus were exceptionally abundant in one sample, indicating a potential C1/methane-cycling hotspot in the Slate River floodplain system.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38422227

RESUMO

SARS-CoV-2 non-structural protein 10 (nsp10) is essential for the stimulation of enzymatic activities of nsp14 and nsp16, acting as both an activator and scaffolding protein. Nsp14 is a bifunctional enzyme with the N-terminus containing a 3'-5' exoribonuclease (ExoN) domain that allows the excision of nucleotide mismatches at the virus RNA 3'-end, and a C-terminal N7-methyltransferase (N7-MTase) domain. Nsp10 is required for stimulating both ExoN proofreading and the nsp16 2'-O-methyltransferase activities. This makes nsp10 a central player in both viral resistance to nucleoside-based drugs and the RNA cap methylation machinery that helps the virus evade innate immunity. We characterised the interactions between full-length nsp10 (139 residues), N- and C-termini truncated nsp10 (residues 10-133), and nsp10 with a C-terminal truncation (residues 1-133) with nsp14 using microscale thermophoresis, multi-detection SEC, and hydrogen-deuterium (H/D) exchange mass spectrometry. We describe the functional role of the C-terminal region of nsp10 for binding to nsp14 and show that full N- and C-termini of nsp10 are important for optimal binding. In addition, our H/D exchange experiments suggest an intermediary interaction of nsp10 with the N7-MTase domain of nsp14. In summary, our results suggest intermediary steps in the process of association or dissociation of the nsp10-nsp14 complex, involving contacts between the two proteins in regions not identifiable by X-ray crystallography alone.

3.
Expert Rev Clin Pharmacol ; 17(3): 225-234, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38345044

RESUMO

INTRODUCTION: Tyrosine kinase inhibitors (TKIs) have revolutionized survival rates of chronic myeloid leukemia (CML) and Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) and replaced hematopoietic stem cell transplantation (hSCT) as the key treatment option for these patients. More recently, the so-called Philadelphia chromosome-like (Ph-like) ALL has similarly benefitted from TKIs. However, many patients shift from the first generation TKI, imatinib, due to treatment-related toxicities or lack of treatment efficacy. A more personalized approach to TKI treatment could counteract these challenges and potentially be more cost-effective. Therapeutic drug monitoring (TDM) has led to higher response rates and less treatment-related toxicity in adult CML but is rarely used in ALL or in childhood CML. AREAS COVERED: This review summarizes different antileukemic treatment indications for TKIs with focus on imatinib and its pharmacokinetic/-dynamic properties as well as opportunities and pitfalls of TDM for imatinib treatment in relation to pharmacogenetics and co-medication for pediatric and adult Ph+/Ph-like leukemias. EXPERT OPINION: TDM of imatinib adds value to standard monitoring of ABL-class leukemia by uncovering non-adherence and potentially mitigating adverse effects. Clinically implementable pharmacokinetic/-dynamic models adjusted for relevant pharmacogenetics could improve individual dosing. Prospective trials of TDM-based treatments, including both children and adults, are needed.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Cromossomo Filadélfia , Adulto , Humanos , Criança , Mesilato de Imatinib/efeitos adversos , Monitoramento de Medicamentos , Estudos Prospectivos , Inibidores de Proteínas Quinases/efeitos adversos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética
4.
Microbiol Resour Announc ; 12(12): e0080023, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-37929976

RESUMO

San Francisco Bay (SFB) is a large and highly human-impacted estuarine system. We produced 449 metagenome-assembled genomes from SFB waters, collected along the salinity gradient, providing a rich data set to compare the metabolic potential of microorganisms from different salinity zones within SFB and to other estuarine systems.

5.
RSC Med Chem ; 14(11): 2277-2300, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38020072

RESUMO

The upswing of antibiotic resistance is an escalating threat to human health. Resistance mediated by bacterial metallo-ß-lactamases is of particular concern as these enzymes degrade ß-lactams, our most frequently prescribed class of antibiotics. Inhibition of metallo-ß-lactamases could allow the continued use of existing ß-lactam antibiotics, such as penicillins, cephalosporins and carbapenems, whose applicability is becoming ever more limited. The design, synthesis, and NDM-1, VIM-2, and GIM-1 inhibitory activities (IC50 4.1-506 µM) of a series of novel non-cytotoxic α-aminophosphonate-based inhibitor candidates are presented herein. We disclose the solution NMR spectroscopic and computational investigation of their NDM-1 and VIM-2 binding sites and binding modes. Whereas the binding modes of the inhibitors are similar, VIM-2 showed a somewhat higher conformational flexibility, and complexed a larger number of inhibitor candidates in more varying binding modes than NDM-1. Phosphonate-type inhibitors may be potential candidates for development into therapeutics to combat metallo-ß-lactamase resistant bacteria.

6.
Ugeskr Laeger ; 185(46)2023 11 13.
Artigo em Dinamarquês | MEDLINE | ID: mdl-37987440
7.
Int J Mol Sci ; 24(17)2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37686452

RESUMO

The ß-coronavirus family, encompassing Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), Severe Acute Respiratory Syndrome Coronavirus (SARS), and Middle East Respiratory Syndrome Coronavirus (MERS), has triggered pandemics within the last two decades. With the possibility of future pandemics, studying the coronavirus family members is necessary to improve knowledge and treatment. These viruses possess 16 non-structural proteins, many of which play crucial roles in viral replication and in other vital functions. One such vital protein is non-structural protein 10 (nsp10), acting as a pivotal stimulator of nsp14 and nsp16, thereby influencing RNA proofreading and viral RNA cap formation. Studying nsp10 of pathogenic coronaviruses is central to unraveling its multifunctional roles. Our study involves the biochemical and biophysical characterisation of full-length nsp10 from MERS, SARS and SARS-CoV-2. To elucidate their oligomeric state, we employed a combination of Multi-detection Size exclusion chromatography (Multi-detection SEC) with multi-angle static light scattering (MALS) and small angle X-ray scattering (SAXS) techniques. Our findings reveal that full-length nsp10s primarily exist as monomers in solution, while truncated versions tend to oligomerise. SAXS experiments reveal a globular shape for nsp10, a trait conserved in all three coronaviruses, although MERS nsp10, diverges most from SARS and SARS-CoV-2 nsp10s. In summary, unbound nsp10 proteins from SARS, MERS, and SARS-CoV-2 exhibit a globular and predominantly monomeric state in solution.


Assuntos
COVID-19 , Coronavírus da Síndrome Respiratória do Oriente Médio , Humanos , SARS-CoV-2 , Espalhamento a Baixo Ângulo , Difração de Raios X , Raios X
8.
Scand J Pain ; 23(4): 751-758, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37694875

RESUMO

OBJECTIVES: Studies suggest that a range of pain mechanisms, such as poor quality of sleep, perceived stress, pain catastrophizing or pain sensitivity, are likely to enhance clinical pain. Animal studies suggest that these pain mechanisms can be modulated by increasing physical activity, but human data are needed to support this hypothesis. This exploratory study aimed to investigate the changes in pain mechanisms after a simple self-directed walking program of 8-weeks. Additionally, this exploratory study investigated the interaction between changes over time in assessments of poor quality of sleep, perceived stress, pain catastrophizing or pain sensitivity and how these changes interacted with each other. METHODS: This prospective cohort study included 30 healthy subjects who were assessed at baseline and 4- and 8-weeks after initiating the walking program (30 min walking/day for 8 weeks). Self-report outcomes included: Pain Catastrophizing Scale (PCS), the Perceived Stress Scale (PSS) and Pittsburgh Sleep Quality Index. Pressure pain thresholds, temporal summation of pain and conditioned pain modulation (CPM) were assessed using cuff algometry. RESULTS: Twenty-four subjects completed all the visits (age: 42.2, SD: 14.9, 16 females). PCS and PSS significantly decreased at the 8-week's visit compared to baseline (p<0.05). No significant differences were seen for an improvement in quality of sleep (p=0.071) and pain sensitivity (p>0.075) when comparing the 8-week's visit to the baseline visit. Changes in pain mechanisms comparing baseline and 8-weeks data were calculated and regression analyses found that an improvement in PCS was associated with an improvement in CPM (R2=0.197, p=0.017) and that a higher adherence to the walking program was associated with a larger improvement in PCS (R2=0.216, p=0.013). CONCLUSIONS: The current exploratory study indicates that a simple self-directed walking program of 8-weeks can improve pain catastrophizing thoughts, perceived stress. Higher adherence to the walking program were associated with an improvement in pain catastrophizing and an improvement in pain catastrophizing was associated with an increase in conditioned pain modulation.


Assuntos
Dor , Caminhada , Feminino , Humanos , Adulto , Estudos Prospectivos , Medição da Dor , Estresse Psicológico , Catastrofização
9.
mBio ; 14(4): e0123623, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37404012

RESUMO

Prochlorococcus is an abundant photosynthetic bacterium in the open ocean, where nitrogen (N) often limits phytoplankton growth. In the low-light-adapted LLI clade of Prochlorococcus, nearly all cells can assimilate nitrite (NO2-), with a subset capable of assimilating nitrate (NO3-). LLI cells are maximally abundant near the primary NO2- maximum layer, an oceanographic feature that may, in part, be due to incomplete assimilatory NO3- reduction and subsequent NO2- release by phytoplankton. We hypothesized that some Prochlorococcus exhibit incomplete assimilatory NO3- reduction and examined NO2- accumulation in cultures of three Prochlorococcus strains (MIT0915, MIT0917, and SB) and two Synechococcus strains (WH8102 and WH7803). Only MIT0917 and SB accumulated external NO2- during growth on NO3-. Approximately 20-30% of the NO3- transported into the cell by MIT0917 was released as NO2-, with the rest assimilated into biomass. We further observed that co-cultures using NO3- as the sole N source could be established for MIT0917 and Prochlorococcus strain MIT1214 that can assimilate NO2- but not NO3-. In these co-cultures, the NO2- released by MIT0917 is efficiently consumed by its partner strain, MIT1214. Our findings highlight the potential for emergent metabolic partnerships that are mediated by the production and consumption of N cycle intermediates within Prochlorococcus populations. IMPORTANCE Earth's biogeochemical cycles are substantially driven by microorganisms and their interactions. Given that N often limits marine photosynthesis, we investigated the potential for N cross-feeding within populations of Prochlorococcus, the numerically dominant photosynthetic cell in the subtropical open ocean. In laboratory cultures, some Prochlorococcus cells release extracellular NO2- during growth on NO3-. In the wild, Prochlorococcus populations are composed of multiple functional types, including those that cannot use NO3- but can still assimilate NO2-. We show that metabolic dependencies arise when Prochlorococcus strains with complementary NO2- production and consumption phenotypes are grown together on NO3-. These findings demonstrate the potential for emergent metabolic partnerships, possibly modulating ocean nutrient gradients, that are mediated by cross-feeding of N cycle intermediates.


Assuntos
Prochlorococcus , Synechococcus , Nitritos/metabolismo , Dióxido de Nitrogênio/metabolismo , Nitratos/metabolismo , Synechococcus/genética , Fitoplâncton
10.
Methods Mol Biol ; 2652: 55-77, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37093470

RESUMO

The baculovirus expression vector system (BEVS) is one of the most popular eukaryotic systems for recombinant protein production. The focus of our protein production platform is the provision of recombinant proteins for research use, where generally only small quantities are required, in the range of tens of micrograms to a few hundred milligrams. Here, we present methods that reflect our standard operating procedures and setup to be able to frequently, and often repeatedly, produce many different types of proteins.


Assuntos
Baculoviridae , Vetores Genéticos , Baculoviridae/genética , Proteínas Recombinantes/metabolismo
11.
ISME J ; 17(4): 620-629, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36739346

RESUMO

The Order Pelagibacterales (SAR11) is the most abundant group of heterotrophic bacterioplankton in global oceans and comprises multiple subclades with unique spatiotemporal distributions. Subclade IIIa is the primary SAR11 group in brackish waters and shares a common ancestor with the dominant freshwater IIIb (LD12) subclade. Despite its dominance in brackish environments, subclade IIIa lacks systematic genomic or ecological studies. Here, we combine closed genomes from new IIIa isolates, new IIIa MAGS from San Francisco Bay (SFB), and 460 highly complete publicly available SAR11 genomes for the most comprehensive pangenomic study of subclade IIIa to date. Subclade IIIa represents a taxonomic family containing three genera (denoted as subgroups IIIa.1, IIIa.2, and IIIa.3) that had distinct ecological distributions related to salinity. The expansion of taxon selection within subclade IIIa also established previously noted metabolic differentiation in subclade IIIa compared to other SAR11 subclades such as glycine/serine prototrophy, mosaic glyoxylate shunt presence, and polyhydroxyalkanoate synthesis potential. Our analysis further shows metabolic flexibility among subgroups within IIIa. Additionally, we find that subclade IIIa.3 bridges the marine and freshwater clades based on its potential for compatible solute transport, iron utilization, and bicarbonate management potential. Pure culture experimentation validated differential salinity ranges in IIIa.1 and IIIa.3 and provided detailed IIIa cell size and volume data. This study is an important step forward for understanding the genomic, ecological, and physiological differentiation of subclade IIIa and the overall evolutionary history of SAR11.


Assuntos
Alphaproteobacteria , Águas Salinas , Filogenia , Oceanos e Mares , Genômica , Evolução Biológica , Alphaproteobacteria/genética , Água do Mar
12.
J Am Heart Assoc ; 11(14): e025657, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35861827

RESUMO

Background Excess visceral adiposity is associated with increased risk of cardiometabolic disorders. Short-term well-controlled clinical trials suggest that regular avocado consumption favorably affects body weight, visceral adiposity, and satiety. Methods and Results The HAT Trial (Habitual Diet and Avocado Trial) was a multicenter, randomized, controlled parallel-arm trial designed to test whether consuming 1 large avocado per day for 6 months in a diverse group of free-living individuals (N=1008) with an elevated waist circumference compared with a habitual diet would decrease visceral adiposity as measured by magnetic resonance imaging. Secondary and additional end points related to risk factors associated with cardiometabolic disorders were assessed. The primary outcome, change in visceral adipose tissue volume during the intervention period, was not significantly different between the Avocado Supplemented and Habitual Diet Groups (estimated mean difference (0.017 L [-0.024 L, 0.058 L], P=0.405). No significant group differences were observed for the secondary outcomes of hepatic fat fraction, hsCRP (high-sensitivity C-reactive protein), and components of the metabolic syndrome. Of the additional outcome measures, modest but nominally significant reductions in total and low-density lipoprotein cholesterol were observed in the Avocado Supplemented compared with the Habitual Diet Group. Changes in the other additional and post hoc measures (body weight, body mass index, insulin, very low-density lipoprotein concentrations, and total cholesterol:high-density lipoprotein cholesterol ratio) were similar between the 2 groups. Conclusions Addition of 1 avocado per day to the habitual diet for 6 months in free-living individuals with elevated waist circumference did not reduce visceral adipose tissue volume and had minimal effect on risk factors associated with cardiometabolic disorders. Registration URL: https://clinicaltrials.gov; Unique identifier: NCT03528031.


Assuntos
Doenças Cardiovasculares , Dieta , Obesidade Abdominal , Persea , Adiposidade , Índice de Massa Corporal , Peso Corporal , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , HDL-Colesterol/metabolismo , LDL-Colesterol/metabolismo , Frutas , Humanos , Obesidade Abdominal/complicações
13.
Front Cell Dev Biol ; 10: 892006, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35646927

RESUMO

The importance of chromatin environment for DNA repair has gained increasing recognition in recent years. The nucleolus is the largest sub-compartment within the nucleus: it has distinct biophysical properties, selective protein retention, and houses the specialized ribosomal RNA genes (collectively referred to as rDNA) with a unique chromatin composition. These genes have high transcriptional activity and a repetitive nature, making them susceptible to DNA damage and resulting in the highest frequency of rearrangements across the genome. A distinct DNA damage response (DDR) secures the fidelity of this genomic region, the so-called nucleolar DDR (n-DDR). The composition of the n-DDR reflects the characteristics of nucleolar chromatin with the nucleolar protein Treacle (also referred to as TCOF1) as a central coordinator retaining several well-characterized DDR proteins in the nucleolus. In this review, we bring together data on the structure of Treacle, its known functions in ribosome biogenesis, and its involvement in multiple branches of the n-DDR to discuss their interconnection. Furthermore, we discuss how the functions of Treacle in ribosome biogenesis and in the n-DDR may contribute to Treacher Collins Syndrome, a disease caused by mutations in Treacle. Finally, we outline outstanding questions that need to be addressed for a more comprehensive understanding of Treacle, the n-DDR, and the coordination of ribosome biogenesis and DNA repair.

14.
ACS Omega ; 7(5): 4550-4562, 2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35155946

RESUMO

Being the second leading cause of death and the leading cause of disability-adjusted life years worldwide, infectious diseases remain-contrary to earlier predictions-a major consideration for the public health of the 21st century. Resistance development of microbes to antimicrobial drugs constitutes a large part of this devastating problem. The most widely spread mechanism of bacterial resistance operates through the degradation of existing ß-lactam antibiotics. Inhibition of metallo-ß-lactamases is expected to allow the continued use of existing antibiotics, whose applicability is becoming ever more limited. Herein, we describe the synthesis, the metallo-ß-lactamase inhibition activity, the cytotoxicity studies, and the NMR spectroscopic determination of the protein binding site of phosphonamidate monoesters. The expression of single- and double-labeled NDM-1 and its backbone NMR assignment are also disclosed, providing helpful information for future development of NDM-1 inhibitors. We show phosphonamidates to have the potential to become a new generation of antibiotic therapeutics to combat metallo-ß-lactamase-resistant bacteria.

15.
mSystems ; 7(1): e0127021, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35076275

RESUMO

Ammonia-oxidizing archaea (AOA) are key for the transformation of ammonia to oxidized forms of nitrogen in aquatic environments around the globe, including nutrient-rich coastal and estuarine waters such as San Francisco Bay (SFB). Using metagenomics and 16S rRNA gene amplicon libraries, we found that AOA are more abundant than ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), except in the freshwater stations in SFB. In South SFB, we observed recurrent AOA blooms of "Candidatus Nitrosomarinus catalina" SPOT01-like organisms, which account for over 20% of 16S rRNA gene amplicons in both surface and bottom waters and co-occur with weeks of high nitrite concentrations (>10 µM) in the oxic water column. We observed pronounced nitrite peaks occurring in the autumn for 7 of the last 9 years (2012 to 2020), suggesting that seasonal AOA blooms are common in South SFB. We recovered two high-quality AOA metagenome-assembled genomes (MAGs), including a Nitrosomarinus-like genome from the South SFB bloom and another Nitrosopumilus genome originating from Suisun Bay in North SFB. Both MAGs cluster with genomes from other estuarine/coastal sites. Analysis of Nitrosomarinus-like genomes show that they are streamlined, with low GC content and high coding density, and harbor urease genes. Our findings support the unique niche of Nitrosomarinus-like organisms which dominate coastal/estuarine waters and provide insights into recurring AOA blooms in SFB. IMPORTANCE Ammonia-oxidizing archaea (AOA) carry out key transformations of ammonia in estuarine systems such as San Francisco Bay (SFB)-the largest estuary on the west coast of North America-and play a significant role in both local and global nitrogen cycling. Using metagenomics and 16S rRNA gene amplicon libraries, we document a massive, recurrent AOA bloom in South SFB that co-occurs with months of high nitrite concentrations in the oxic water column. Our study is the first to generate metagenome-assembled genomes (MAGs) from SFB, and through this process we recovered two high-quality AOA MAGs, one of which originated from bloom samples. These AOA MAGs yield new insight into the Nitrosopumilus and Nitrosomarinus-like lineages and their potential niches in coastal and estuarine systems. Nitrosomarinus-like AOA are abundant in coastal regions around the globe, and we highlight the common occurrence of urease genes, low GC content, and range of salinity tolerances within this lineage.


Assuntos
Amônia , Archaea , Metagenômica , Baías , Metagenoma , São Francisco , RNA Ribossômico 16S , Estações do Ano , Nitritos , Urease/genética , Oxirredução , Sedimentos Geológicos/microbiologia , Água , Nitrogênio
16.
Limnol Oceanogr ; 66(9): 3300-3312, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34690365

RESUMO

The picocyanobacteria Prochlorococcus and Synechococcus are found throughout the ocean's euphotic zone, where the daily light:dark cycle drives their physiology. Periodic deep mixing events can, however, move cells below this region, depriving them of light for extended periods of time. Here, we demonstrate that members of these genera can adapt to tolerate repeated periods of light energy deprivation. Strains kept in the dark for 3 d and then returned to the light initially required 18-26 d to resume growth, but after multiple rounds of dark exposure they began to regrow after only 1-2 d. This dark-tolerant phenotype was stable and heritable; some cultures retained the trait for over 132 generations even when grown in a standard 13:11 light:dark cycle. We found no genetic differences between the dark-tolerant and parental strains of Prochlorococcus NATL2A, indicating that an epigenetic change is likely responsible for the adaptation. To begin to explore this possibility, we asked whether DNA methylation-one potential mechanism mediating epigenetic inheritance in bacteria-occurs in Prochlorococcus. LC-MS/MS analysis showed that while DNA methylations, including 6 mA and 5 mC, are found in some other Prochlorococcus strains, there were no methylations detected in either the parental or dark-tolerant NATL2A strains. These findings suggest that Prochlorococcus utilizes a yet-to-be-determined epigenetic mechanism to adapt to the stress of extended light energy deprivation, and highlights phenotypic heterogeneity as an additional dimension of Prochlorococcus diversity.

17.
Healthc (Amst) ; 9(1): 100509, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33517179

RESUMO

INTERVENTION: This pilot study was a 16-week Telehealth intervention using wearable devices, automated text messaging, and trained health coaching, in primary care clinics of an academic medical center. Thirty patients were enrolled in three cohorts, ages 18-64, BMI > 27, and MVPA < 150 minutes per week. The primary outcome was weight loss per week. RESULTS: Twenty-two participants had a significant median weight loss of -0.29 kg per week and mean change of -3.9 kg in total weight, -1.8 in BMI, and -3.8% of total bodyweight (all P<.001). MVPA increased 67 min per week (P=.003). CONCLUSION: This pilot telehealth intervention suggests that, when combined, these tools may be used effectively by primary care teams to promote weight loss and physical activity in their patients.


Assuntos
Telemedicina , Redução de Peso , Adolescente , Adulto , Exercício Físico , Humanos , Pessoa de Meia-Idade , Obesidade/terapia , Sobrepeso/terapia , Projetos Piloto , Atenção Primária à Saúde , Adulto Jovem
18.
Microb Ecol ; 81(3): 601-616, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33150499

RESUMO

Despite being the largest estuary on the west coast of North America, no in-depth survey of microbial communities in San Francisco Bay (SFB) waters currently exists. In this study, we analyze bacterioplankton and archaeoplankton communities at several taxonomic levels and spatial extents (i.e., North versus South Bay) to reveal patterns in alpha and beta diversity. We assess communities using high-throughput sequencing of the 16S rRNA gene in 177 water column samples collected along a 150-km transect over a 2-year monthly time-series. In North Bay, the microbial community is strongly structured by spatial salinity changes while in South Bay seasonal variations dominate community dynamics. Along the steep salinity gradient in North Bay, we find that operational taxonomic units (OTUs; 97% identity) have higher site specificity than at coarser taxonomic levels and turnover ("species" replacement) is high, revealing a distinct brackish community (in oligo-, meso-, and polyhaline samples) from fresh and marine end-members. At coarser taxonomic levels (e.g., phylum, class), taxa are broadly distributed across salinity zones (i.e., present/abundant in a large number of samples) and brackish communities appear to be a mix of fresh and marine communities. We also observe variations in brackish communities between samples with similar salinities, likely related to differences in water residence times between North and South Bay. Throughout SFB, suspended particulate matter is positively correlated with richness and influences changes in beta diversity. Within several abundant groups, including the SAR11 clade (comprising up to 30% of reads in a sample), OTUs appear to be specialized to a specific salinity range. Some other organisms also showed pronounced seasonal abundance, including Synechococcus, Ca. Actinomarina, and Nitrosopumilus-like OTUs. Overall, this study represents the first in-depth spatiotemporal survey of SFB microbial communities and provides insight into how planktonic microorganisms have specialized to different niches along the salinity gradient.


Assuntos
Archaea , Plâncton , Archaea/genética , Baías , Plâncton/genética , RNA Ribossômico 16S/genética , São Francisco
19.
Geriatrics (Basel) ; 5(4)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33213075

RESUMO

Rheumatoid arthritis (RA) is characterised by a chronic, progressive inflammation in the joints and leads to substantial pain, disability, and other morbidities. Few studies document the occurrence of insufficiency fractures, but no studies document the patient's perspective on incurring an insufficiency fracture. The aim of this qualitative study was to explore the patients' perspective on how insufficiency fractures influence their level of activity and to detect their need for rehabilitation. Two focus-group interviews were performed with 10 patients diagnosed with RA and insufficiency fractures. The data from the focus-group interviews were subjected to thematic analysis to provide a sense of the important themes. The 10 patients were all females, aged 57-88 years. Magnetic resonance imaging were performed at a mean of six months and seven days. All patients identified the delayed diagnosis of fracture as a significant burden. They experienced pain but did not receive a diagnosis. When the patients were immobilised, some of them were offered aids such as crutches, which they were unable to use due to their RA. The patients needed a focus on diagnosis and individually customised rehabilitation, taking into account RA and including guidance concerning daily activities, aids, and the regain of physical function.

20.
Int J Mol Sci ; 21(19)2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33036230

RESUMO

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), causing Coronavirus Disease 19 (COVID-19), emerged at the end of 2019 and quickly spread to cause a global pandemic with severe socio-economic consequences. The early sequencing of its RNA genome revealed its high similarity to SARS, likely to have originated from bats. The SARS-CoV-2 non-structural protein 10 (nsp10) displays high sequence similarity with its SARS homologue, which binds to and stimulates the 3'-to-5' exoribonuclease and the 2'-O-methlytransferase activities of nsps 14 and 16, respectively. Here, we report the biophysical characterization and 1.6 Å resolution structure of the unbound form of nsp10 from SARS-CoV-2 and compare it to the structures of its SARS homologue and the complex-bound form with nsp16 from SARS-CoV-2. The crystal structure and solution behaviour of nsp10 will not only form the basis for understanding the role of SARS-CoV-2 nsp10 as a central player of the viral RNA capping apparatus, but will also serve as a basis for the development of inhibitors of nsp10, interfering with crucial functions of the replication-transcription complex and virus replication.


Assuntos
Simulação de Dinâmica Molecular , Proteínas Virais Reguladoras e Acessórias/química , Sítios de Ligação , Cristalografia por Raios X , Ligação Proteica , S-Adenosilmetionina/química , S-Adenosilmetionina/metabolismo , Homologia de Sequência , Proteínas Virais Reguladoras e Acessórias/metabolismo , Dedos de Zinco
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