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1.
Br Dent J ; 235(10): 789-795, 2023 11.
Article in English | MEDLINE | ID: mdl-38001200

ABSTRACT

In this paper, the actions needed to manage specific medical emergencies are discussed. Each emergency requires a correct diagnosis to be made for effective and safe management. The basis of management in contemporary dental practice avoids the intravenous route where drugs are required to treat the emergency.


Subject(s)
Emergencies , Emergency Treatment , Humans
2.
Am J Physiol Renal Physiol ; 324(6): F590-F602, 2023 06 01.
Article in English | MEDLINE | ID: mdl-37141147

ABSTRACT

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the formation of numerous fluid-filled cysts that lead to progressive loss of functional nephrons. Currently, there is an unmet need for diagnostic and prognostic indicators of early stages of the disease. Metabolites were extracted from the urine of patients with early-stage ADPKD (n = 48 study participants) and age- and sex-matched normal controls (n = 47) and analyzed by liquid chromatography-mass spectrometry. Orthogonal partial least squares-discriminant analysis was used to generate a global metabolomic profile of early ADPKD for the identification of metabolic pathway alterations and discriminatory metabolites as candidates of diagnostic and prognostic biomarkers. The global metabolomic profile exhibited alterations in steroid hormone biosynthesis and metabolism, fatty acid metabolism, pyruvate metabolism, amino acid metabolism, and the urea cycle. A panel of 46 metabolite features was identified as candidate diagnostic biomarkers. Notable putative identities of candidate diagnostic biomarkers for early detection include creatinine, cAMP, deoxycytidine monophosphate, various androgens (testosterone; 5-α-androstane-3,17,dione; trans-dehydroandrosterone), betaine aldehyde, phosphoric acid, choline, 18-hydroxycorticosterone, and cortisol. Metabolic pathways associated with variable rates of disease progression included steroid hormone biosynthesis and metabolism, vitamin D3 metabolism, fatty acid metabolism, the pentose phosphate pathway, tricarboxylic acid cycle, amino acid metabolism, sialic acid metabolism, and chondroitin sulfate and heparin sulfate degradation. A panel of 41 metabolite features was identified as candidate prognostic biomarkers. Notable putative identities of candidate prognostic biomarkers include ethanolamine, C20:4 anandamide phosphate, progesterone, various androgens (5-α-dihydrotestosterone, androsterone, etiocholanolone, and epiandrosterone), betaine aldehyde, inflammatory lipids (eicosapentaenoic acid, linoleic acid, and stearolic acid), and choline. Our exploratory data support metabolic reprogramming in early ADPKD and demonstrate the ability of liquid chromatography-mass spectrometry-based global metabolomic profiling to detect metabolic pathway alterations as new therapeutic targets and biomarkers for early diagnosis and tracking disease progression of ADPKD.NEW & NOTEWORTHY To our knowledge, this study is the first to generate urinary global metabolomic profiles from individuals with early-stage ADPKD with preserved renal function for biomarker discovery. The exploratory dataset reveals metabolic pathway alterations that may be responsible for early cystogenesis and rapid disease progression and may be potential therapeutic targets and pathway sources for candidate biomarkers. From these results, we generated a panel of candidate diagnostic and prognostic biomarkers of early-stage ADPKD for future validation.


Subject(s)
Polycystic Kidney, Autosomal Dominant , Humans , Polycystic Kidney, Autosomal Dominant/diagnosis , Androgens , Biomarkers/urine , Metabolomics/methods , Disease Progression , Metabolic Networks and Pathways , Choline , Amino Acids , Fatty Acids , Steroids
3.
Nat Commun ; 13(1): 7670, 2022 12 12.
Article in English | MEDLINE | ID: mdl-36509784

ABSTRACT

While autopsy studies identify many abnormalities in the central nervous system (CNS) of subjects dying with neurological diseases, without their quantification in living subjects across the lifespan, pathogenic processes cannot be differentiated from epiphenomena. Using machine learning (ML), we searched for likely pathogenic mechanisms of multiple sclerosis (MS). We aggregated cerebrospinal fluid (CSF) biomarkers from 1305 proteins, measured blindly in the training dataset of untreated MS patients (N = 129), into models that predict past and future speed of disability accumulation across all MS phenotypes. Healthy volunteers (N = 24) data differentiated natural aging and sex effects from MS-related mechanisms. Resulting models, validated (Rho 0.40-0.51, p < 0.0001) in an independent longitudinal cohort (N = 98), uncovered intra-individual molecular heterogeneity. While candidate pathogenic processes must be validated in successful clinical trials, measuring them in living people will enable screening drugs for desired pharmacodynamic effects. This will facilitate drug development making, it hopefully more efficient and successful.


Subject(s)
Multiple Sclerosis , Nervous System Diseases , Humans , Multiple Sclerosis/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , Models, Molecular
4.
Mol Syst Biol ; 18(3): e10140, 2022 03.
Article in English | MEDLINE | ID: mdl-35312157

ABSTRACT

Individual plant cells possess a genetic network, the circadian clock, that times internal processes to the day-night cycle. Mathematical models of the clock are typically either "whole-plant" that ignore tissue or cell type-specific clock behavior, or "phase-only" that do not include molecular components. To address the complex spatial coordination observed in experiments, here we implemented a clock network model on a template of a seedling. In our model, the sensitivity to light varies across the plant, and cells communicate their timing via local or long-distance sharing of clock components, causing their rhythms to couple. We found that both varied light sensitivity and long-distance coupling could generate period differences between organs, while local coupling was required to generate the spatial waves of clock gene expression observed experimentally. We then examined our model under noisy light-dark cycles and found that local coupling minimized timing errors caused by the noise while allowing each plant region to maintain a different clock phase. Thus, local sensitivity to environmental inputs combined with local coupling enables flexible yet robust circadian timing.


Subject(s)
Circadian Clocks , Circadian Clocks/genetics , Circadian Rhythm/genetics , Gene Regulatory Networks , Photoperiod , Seedlings/genetics
5.
Methods Mol Biol ; 2398: 47-55, 2022.
Article in English | MEDLINE | ID: mdl-34674166

ABSTRACT

The A. thaliana circadian clock is an example of a gene network that generates rich temporal and spatial dynamics. Bioluminescent imaging has proven a powerful method to help dissect the genetic mechanisms that generate oscillations of gene expression over the course of the day. However, its use for the study of spatial regulation is often limited by resolution. Here, we describe a modified luciferase imaging method for the study of the Arabidopsis circadian clock across the plant at sub-tissue-level resolution.


Subject(s)
Arabidopsis , Circadian Clocks , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Circadian Clocks/genetics , Circadian Rhythm , Gene Expression Regulation, Plant , Luciferases/genetics , Luciferases/metabolism
6.
NPJ Sci Food ; 5(1): 9, 2021 May 04.
Article in English | MEDLINE | ID: mdl-33947871

ABSTRACT

Achieving food security is a critical challenge of the Anthropocene that may conflict with environmental and societal goals such as increased energy access. The "fuel versus food" debate coupled with climate mitigation efforts has given rise to next-generation biofuels. Findings of this systematic review indicate just over half of the studies (56% of 224 publications) reported a negative impact of bioenergy production on food security. However, no relationship was found between bioenergy feedstocks that are edible versus inedible and food security (P value = 0.15). A strong relationship was found between bioenergy and type of food security parameter (P value < 0.001), sociodemographic index of study location (P value = 0.001), spatial scale (P value < 0.001), and temporal scale (P value = 0.017). Programs and policies focused on bioenergy and climate mitigation should monitor multiple food security parameters at various scales over the long term toward achieving diverse sustainability goals.

7.
Plants (Basel) ; 10(4)2021 Mar 24.
Article in English | MEDLINE | ID: mdl-33804836

ABSTRACT

Atmospheric carbon dioxide concentrations [CO2] are increasing steadily. Some reports have shown that root growth in grain crops is mostly stimulated in the topsoil rather than evenly throughout the soil profile by e[CO2], which is not optimal for crops grown in semi-arid environments with strong reliance on stored water. An experiment was conducted during the 2014 and 2015 growing seasons with two lentil (Lens culinaris) genotypes grown under Free Air CO2 Enrichment (FACE) in which root growth was observed non-destructively with mini-rhizotrons approximately every 2-3 weeks. Root growth was not always statistically increased by e[CO2] and not consistently between depths and genotypes. In 2014, root growth in the top 15 cm of the soil profile (topsoil) was indeed increased by e[CO2], but increases at lower depths (30-45 cm) later in the season were greater than in the topsoil. In 2015, e[CO2] only increased root length in the topsoil for one genotype, potentially reflecting the lack of plant available soil water between 30-60 cm until recharged by irrigation during grain filling. Our limited data to compare responses to e[CO2] showed that root length increases in the topsoil were correlated with a lower yield response to e[CO2]. The increase in yield response was rather correlated with increases in root growth below 30 cm depth.

8.
Br Dent J ; 230(6): 351-357, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33772188

ABSTRACT

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. It is a major health concern and causes substantial morbidity and mortality. It is imperative that the signs of sepsis are identified early in both adult and paediatric patients and appropriately escalated to initiate early treatment and improve prognosis. This paper aims to discuss the change in classification from the previous systemic inflammatory response syndrome (SIRS) criteria to the current definition in adults and also the unchanged definition in children. The hallmark signs of sepsis (both red and amber flags) are discussed in relation to their underlying cellular mechanisms to provide a comprehensive overview for clinicians in primary care, hospital and community settings. The rise of antimicrobial resistance is also an increasing global health concern with resistant bacteria from common infections likely to result in greater patient morbidity and worse outcomes.A literature search identified reported sepsis cases in dentistry through searches in Ovid Medline and Embase from January 1990 to December 2019. Only primary studies were included with no restrictions on languages. Four articles were identified which reported sepsis associated with tooth extractions, dental abscess and submental/submandibular cellulitis. It is well known that locoregional infections of dental origin have the potential to cause sepsis. Therefore, dental healthcare professionals need to be vigilant and understand the specific signs and escalation protocols to ensure patient safety.


Subject(s)
Sepsis , Adult , Child , Dentistry , Humans , Prognosis , Sepsis/diagnosis , Systemic Inflammatory Response Syndrome/diagnosis
9.
Br Dent J ; 228(11): 842-848, 2020 06.
Article in English | MEDLINE | ID: mdl-32541745

ABSTRACT

Introduction The COVID-19 pandemic has posed many challenges, including provision of urgent dental care. This paper presents a prospective service evaluation during establishment of urgent dental care in the North East of England over a six-week period.Aim To monitor patient volumes, demographics and outcomes at the North East urgent dental care centre and confirm appropriate care pathways.Main outcome methods Data were collected on key characteristics of patients accessing urgent care from 23 March to 3 May 2020. Analysis was with descriptive statistics.Results There were 1,746 patient triages (1,595 telephone and 151 face-to-face), resulting in 1,322 clinical consultations. The most common diagnoses were symptomatic irreversible pulpitis or apical periodontitis. Sixty-five percent of clinical consultations resulted in extractions and 0.8% in an aerosol generating procedure. Patients travelled 25 km on average to access care; however, this reduced as more urgent care centres were established. The majority of patients were asymptomatic of COVID-19 and, to our knowledge, no staff acquired infection due to occupational exposure.Conclusion The urgent dental care centre effectively managed urgent and emergency dental care, with appropriate patient pathways established over the six-week period. Dental preparedness for future pandemic crises could be improved and informed by this data.


Subject(s)
Ambulatory Care Facilities , Pandemics , Betacoronavirus , COVID-19 , Coronavirus Infections , Dental Care , England , Humans , Pneumonia, Viral , Prospective Studies , SARS-CoV-2 , United Kingdom
10.
J Healthc Qual ; 42(1): 12-18, 2020.
Article in English | MEDLINE | ID: mdl-30649004

ABSTRACT

The Choosing Wisely (CW) initiative provides recommendations for healthcare providers, aimed at reducing unnecessary or inappropriate tests and procedures. A clinical decision support (CDS) alert in the electronic health record was developed to reflect organizational CW guidelines regarding blood chemistry panel ordering in the primary care setting. An interrupted time series design was used to analyze the weekly proportion of inappropriate blood chemistry panel orders prior to and after implementation of the CDS alert in treatment and control groups. Implementation of the CDS alert significantly decreased the average weekly proportion of inappropriate blood chemistry panels from 28.64% to 15.69% in the treatment group (p < .001). Apart from other efforts implemented simultaneously to reduce inappropriate lab ordering, the CDS alert produced a significant reduction in inappropriate lab ordering. We conclude that CDS alerts can be an effective strategy for healthcare organizations seeking to more closely adhere to CW guidelines.


Subject(s)
Blood Chemical Analysis/statistics & numerical data , Blood Chemical Analysis/standards , Decision Support Systems, Clinical , Diagnostic Tests, Routine/statistics & numerical data , Diagnostic Tests, Routine/standards , Guidelines as Topic , Unnecessary Procedures/statistics & numerical data , Unnecessary Procedures/standards , Adult , Aged , Aged, 80 and over , Female , Humans , Idaho , Male , Middle Aged , Utah
11.
Curr Opin Plant Biol ; 53: 65-72, 2020 02.
Article in English | MEDLINE | ID: mdl-31783323

ABSTRACT

The circadian clock is a genetic circuit that allows organisms to anticipate daily events caused by the rotation of the Earth. The plant clock regulates physiology at multiple scales, from cell division to ecosystem-scale interactions. It is becoming clear that rather than being a single perfectly synchronised timer throughout the plant, the clock can be sensitive to different cues, run at different speeds, and drive distinct processes in different cell types and tissues. This flexibility may help the plant clock to regulate such a range of developmental and physiological processes. In this review, using examples from the literature, we describe how the clock regulates development at multiple scales and discuss how the clock might allow local flexibility in regulation whilst remaining coordinated across the plant.


Subject(s)
Arabidopsis , Circadian Clocks , Circadian Rhythm , Ecosystem , Plant Development
12.
PLoS Biol ; 17(8): e3000407, 2019 08.
Article in English | MEDLINE | ID: mdl-31415556

ABSTRACT

Individual plant cells have a genetic circuit, the circadian clock, that times key processes to the day-night cycle. These clocks are aligned to the day-night cycle by multiple environmental signals that vary across the plant. How does the plant integrate clock rhythms, both within and between organs, to ensure coordinated timing? To address this question, we examined the clock at the sub-tissue level across Arabidopsis thaliana seedlings under multiple environmental conditions and genetic backgrounds. Our results show that the clock runs at different speeds (periods) in each organ, which causes the clock to peak at different times across the plant in both constant environmental conditions and light-dark (LD) cycles. Closer examination reveals that spatial waves of clock gene expression propagate both within and between organs. Using a combination of modeling and experiment, we reveal that these spatial waves are the result of the period differences between organs and local coupling, rather than long-distance signaling. With further experiments we show that the endogenous period differences, and thus the spatial waves, can be generated by the organ specificity of inputs into the clock. We demonstrate this by modulating periods using light and metabolic signals, as well as with genetic perturbations. Our results reveal that plant clocks can be set locally by organ-specific inputs but coordinated globally via spatial waves of clock gene expression.


Subject(s)
Circadian Clocks/genetics , Circadian Rhythm/physiology , Gene Expression Regulation, Plant/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Circadian Clocks/physiology , Circadian Rhythm/genetics , Gene Regulatory Networks , Organ Specificity/genetics , Photoperiod , Seedlings/genetics , Seedlings/physiology , Signal Transduction , Transcription Factors/metabolism
13.
Plant Methods ; 15: 51, 2019.
Article in English | MEDLINE | ID: mdl-31139241

ABSTRACT

BACKGROUND: A robust circadian clock has been implicated in plant resilience, resource-use efficiency, competitive growth and yield. A huge number of physiological processes are under circadian control in plants including: responses to biotic and abiotic stresses; flowering time; plant metabolism; and mineral uptake. Understanding how the clock functions in crops such as Triticum aestivum (bread wheat) and Brassica napus (oilseed rape) therefore has great agricultural potential. Delayed fluorescence (DF) imaging has been shown to be applicable to a wide range of plant species and requires no genetic transformation. Although DF has been used to measure period length of both mutants and wild ecotypes of Arabidopsis, this assay has never been systematically optimised for crop plants. The physical size of both B. napus and T. aestivum led us to develop a representative sampling strategy which enables high-throughput imaging of these crops. RESULTS: In this study, we describe the plant-specific optimisation of DF imaging to obtain reliable circadian phenotypes with the robustness and reproducibility to detect diverging periods between cultivars of the same species. We find that the age of plant material, light regime and temperature conditions all significantly effect DF rhythms and describe the optimal conditions for measuring robust rhythms in each species. We also show that sections of leaf can be used to obtain period estimates with improved throughput for larger sample size experiments. CONCLUSIONS: We present an optimized protocol for high-throughput phenotyping of circadian period specific to two economically valuable crop plants. Application of this method revealed significant differences between the periods of several widely grown elite cultivars. This method also identified intriguing differential responses of circadian rhythms in T. aestivum compared to B. napus; specifically the dramatic change to rhythm robustness when plants were imaged under constant light versus constant darkness. This points towards diverging networks underlying circadian control in these two species.

14.
Clin Exp Rheumatol ; 37(3): 393-399, 2019.
Article in English | MEDLINE | ID: mdl-30620276

ABSTRACT

OBJECTIVES: The objective of this study was to analyse the metabolomic profiles of rheumatoid arthritis synovial fluid to test the use of global metabolomics by liquid chromatography-mass spectrometry for clinical analysis of synovial fluid. METHODS: Metabolites were extracted from rheumatoid arthritis (n=3) and healthy (n=5) synovial fluid samples using 50:50 water: acetonitrile. Metabolite extracts were analysed in positive mode by normal phase liquid chromatography-mass spectrometry for global metabolomics. Statistical analyses included hierarchical clustering analysis, principal component analysis, Student's t-test, and volcano plot analysis. Metabolites were matched with known metabolite identities using METLIN and enriched for relevant pathways using IMPaLA. RESULTS: 1018 metabolites were detected by LC-MS analysis in synovial fluid from rheumatoid arthritis and healthy patients, with 162 metabolites identified as significantly different between diseased and control. Pathways upregulated with disease included ibuprofen metabolism, glucocorticoid and mineralocorticoid metabolism, alpha-linolenic acid metabolism, and steroid hormone biosynthesis. Pathways downregulated with disease included purine and pyrimidine metabolism, biological oxidations, arginine and proline metabolism, the citrulline-nitric oxide cycle, and glutathione metabolism. Receiver operating characteristic analysis identified 30 metabolites as putative rheumatoid arthritis biomarkers including various phospholipids, diol and its derivatives, arsonoacetate, oleananoic acid acetate, docosahexaenoic acid methyl ester, and linolenic acid and eicosatrienoic acid derivatives. CONCLUSIONS: This study supports the use of global metabolomic profiling by liquid chromatography-mass spectrometry for synovial fluid analysis to provide insight into the aetiology of disease.


Subject(s)
Arthritis, Rheumatoid/metabolism , Metabolomics , Synovial Fluid/metabolism , Biomarkers , Humans , ROC Curve
15.
Prim Dent J ; 7(3): 46-56, 2018 Sep 01.
Article in English | MEDLINE | ID: mdl-30428968

ABSTRACT

Dental practitioners need to have knowledge of the risk assessment, diagnosis and management of medical emergencies. This paper deals with risk assessment and basic management principles, applicable to all emergencies. More specific aspects of medical emergency management are also discussed.


Subject(s)
Emergency Treatment , Risk Assessment , Airway Obstruction/diagnosis , Algorithms , Dentists , Emergencies , Humans
16.
Ann Clin Transl Neurol ; 5(10): 1241-1249, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30349859

ABSTRACT

OBJECTIVE: To develop a sensitive neurological disability scale for broad utilization in clinical practice. METHODS: We employed advances of mobile computing to develop an iPad-based App for convenient documentation of the neurological examination into a secure, cloud-linked database. We included features present in four traditional neuroimmunological disability scales and codified their automatic computation. By combining spatial distribution of the neurological deficit with quantitative or semiquantitative rating of its severity we developed a new summary score (called NeurEx; ranging from 0 to 1349 with minimal measurable change of 0.25) and compared its performance with clinician- and App-computed traditional clinical scales. RESULTS: In the cross-sectional comparison of 906 neurological examinations, the variance between App-computed and clinician-scored disability scales was comparable to the variance between rating of the identical neurological examination by multiple sclerosis (MS)-trained clinicians. By eliminating rating ambiguity, App-computed scales achieved greater accuracy in measuring disability progression over time (n = 191 patients studied over 880.6 patient-years). The NeurEx score had no apparent ceiling effect and more than 200-fold higher sensitivity for detecting a measurable yearly disability progression (i.e., median progression slope of 8.13 relative to minimum detectable change of 0.25) than Expanded Disability Status Scale (EDSS) with a median yearly progression slope of 0.071 that is lower than the minimal measurable change on EDSS of 0.5. INTERPRETATION: NeurEx can be used as a highly sensitive outcome measure in neuroimmunology. The App can be easily modified for use in other areas of neurology and it can bridge private practice practitioners to academic centers in multicenter research studies.

17.
Elife ; 72018 04 26.
Article in English | MEDLINE | ID: mdl-29697372

ABSTRACT

The Arabidopsis circadian clock orchestrates gene regulation across the day/night cycle. Although a multiple feedback loop circuit has been shown to generate the 24-hr rhythm, it remains unclear how robust the clock is in individual cells, or how clock timing is coordinated across the plant. Here we examine clock activity at the single cell level across Arabidopsis seedlings over several days under constant environmental conditions. Our data reveal robust single cell oscillations, albeit desynchronised. In particular, we observe two waves of clock activity; one going down, and one up the root. We also find evidence of cell-to-cell coupling of the clock, especially in the root tip. A simple model shows that cell-to-cell coupling and our measured period differences between cells can generate the observed waves. Our results reveal the spatial structure of the plant clock and suggest that unlike the centralised mammalian clock, the Arabidopsis clock has multiple coordination points.


Subject(s)
Arabidopsis/genetics , Arabidopsis/physiology , Circadian Clocks , Gene Expression Regulation, Plant , Cells , Gene Regulatory Networks , Seedlings
18.
Biochem Biophys Res Commun ; 499(2): 182-188, 2018 05 05.
Article in English | MEDLINE | ID: mdl-29551687

ABSTRACT

Osteoarthritis affects over 250 million individuals worldwide. Currently, there are no options for early diagnosis of osteoarthritis, demonstrating the need for biomarker discovery. To find biomarkers of osteoarthritis in human synovial fluid, we used high performance liquid-chromatography mass spectrometry for global metabolomic profiling. Metabolites were extracted from human osteoarthritic (n = 5), rheumatoid arthritic (n = 3), and healthy (n = 5) synovial fluid, and a total of 1233 metabolites were detected. Principal components analysis clearly distinguished the metabolomic profiles of diseased from healthy synovial fluid. Synovial fluid from rheumatoid arthritis patients contained expected metabolites consistent with the inflammatory nature of the disease. Similarly, unsupervised clustering analysis found that each disease state was associated with distinct metabolomic profiles and clusters of co-regulated metabolites. For osteoarthritis, co-regulated metabolites that were upregulated compared to healthy synovial fluid mapped to known disease processes including chondroitin sulfate degradation, arginine and proline metabolism, and nitric oxide metabolism. We utilized receiver operating characteristic analysis to determine the diagnostic value of each metabolite and identified 35 metabolites as potential biomarkers of osteoarthritis, with an area under the receiver operating characteristic curve >0.9. These metabolites included phosphatidylcholine, lysophosphatidylcholine, ceramides, myristate derivatives, and carnitine derivatives. This pilot study provides strong justification for a larger cohort-based study of human osteoarthritic synovial fluid using global metabolomics. The significance of these data is the demonstration that metabolomic profiling of synovial fluid can identify relevant biomarkers of joint disease.


Subject(s)
Biomarkers/metabolism , Metabolomics/methods , Osteoarthritis/metabolism , Synovial Fluid/metabolism , Arthritis, Rheumatoid/metabolism , Arthritis, Rheumatoid/pathology , Humans , Metabolome , Osteoarthritis/pathology , Principal Component Analysis
19.
Glob Chang Biol ; 24(5): 2182-2197, 2018 05.
Article in English | MEDLINE | ID: mdl-29322639

ABSTRACT

We present the first long-term, highly resolved prokaryotic cell concentration record obtained from a polar ice core. This record, obtained from the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core, spanned from the Last Glacial Maximum (LGM) to the early Holocene (EH) and showed distinct fluctuations in prokaryotic cell concentration coincident with major climatic states. The time series also revealed a ~1,500-year periodicity with greater amplitude during the Last Deglaciation (LDG). Higher prokaryotic cell concentration and lower variability occurred during the LGM and EH than during the LDG. A sevenfold decrease in prokaryotic cell concentration coincided with the LGM/LDG transition and the global 19 ka meltwater pulse. Statistical models revealed significant relationships between the prokaryotic cell record and tracers of both marine (sea-salt sodium [ssNa]) and burning emissions (black carbon [BC]). Collectively, these models, together with visual observations and methanosulfidic acid (MSA) measurements, indicated that the temporal variability in concentration of airborne prokaryotic cells reflected changes in marine/sea-ice regional environments of the WAIS. Our data revealed that variations in source and transport were the most likely processes producing the significant temporal variations in WD prokaryotic cell concentrations. This record provided strong evidence that airborne prokaryotic cell deposition differed during the LGM, LDG, and EH, and that these changes in cell densities could be explained by different environmental conditions during each of these climatic periods. Our observations provide the first ice-core time series evidence for a prokaryotic response to long-term climatic and environmental processes.


Subject(s)
Archaea/classification , Bacteria/classification , Ice Cover/microbiology , Antarctic Regions , History, Ancient , Models, Theoretical , Sodium , Time Factors
20.
Front Neurol ; 8: 577, 2017.
Article in English | MEDLINE | ID: mdl-29176956

ABSTRACT

OBJECTIVE: To perform a meta-analysis of randomized, blinded, multiple sclerosis (MS) clinical trials, to test the hypothesis that efficacy of immunomodulatory disease-modifying therapies (DMTs) on MS disability progression is strongly dependent on age. METHODS: We performed a literature search with pre-defined criteria and extracted relevant features from 38 clinical trials that assessed efficacy of DMTs on disability progression. We fit a linear regression, weighted for trial sample size, and duration, to examine the hypothesis that age has a defining effect on the therapeutic efficacy of immunomodulatory DMTs. RESULTS: More than 28,000 MS subjects participating in trials of 13 categories of immunomodulatory drugs are included in the meta-analysis. The efficacy of immunomodulatory DMTs on MS disability strongly decreased with advancing age (R2 = 0.6757, p = 6.39e-09). Inclusion of baseline EDSS did not significantly improve the model. The regression predicts zero efficacy beyond approximately age 53 years. The comparative efficacy rank derived from the regression residuals differentiates high- and low-efficacy drugs. High-efficacy drugs outperform low-efficacy drugs in inhibiting MS disability only for patients younger than 40.5 years. CONCLUSION: The meta-analysis supports the notion that progressive MS is simply a later stage of the MS disease process and that age is an essential modifier of a drug efficacy. Higher efficacy treatments exert their benefit over lower efficacy treatments only during early stages of MS, and, after age 53, the model suggests that there is no predicted benefit to receiving immunomodulatory DMTs for the average MS patient.

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