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Background Invasive bacterial diseases (IBD) cause significant mortality in young infants. There are limited population-based data on IBD in young infants in Sub-Saharan Africa. Methods We conducted population-based surveillance for IBD among infants aged 0-90 days in a demographic surveillance area in rural Gambia between 1 March 2011 and 31 December 2017. Infants admitted to health facilities within the study area had standardised clinical evaluation plus conventional microbiological investigation. We defined IBD as isolation of pathogenic bacteria from blood, cerebrospinal fluid, lung, or pleural aspirate. We determined incidence, aetiology and case-fatality of IBD. Results A total of 3794 infants were admitted and 3605 (95%) had at least one sample collected for culture. We detected 254 (8.0%) episodes of IBD (bacteraemia 241; meningitis 14; pneumonia seven). The incidence of IBD in infants aged 0-90 days was 25 episodes/1000 person-years (95% confidence interval (CI) = 22-28), the incidence in neonates was 50 episodes/1000 person-years (95% CI = 43-58) and the incidence in infants aged 29-90 days was 12 episodes/1000 person-years (95% CI = 9-15). The most common pathogens causing IBD were Staphylococcus aureus (n = 102, 40%), Escherichia coli (n = 37, 15%), Streptococcus pneumoniae (n = 24, 9%) and Klebsiella pneumoniae (n = 12, 5%). Case-fatality was 29% (95% CI = 23-37) in neonates and 19% (95% CI = 11-29) in infants aged 29-90 days. A minimum of 7.3% of all young infant deaths in the population were caused by IBD. Conclusions IBD are common in young infants in rural Gambia and have a high case-fatality. Strategies are needed to prevent IBD in young infants. Overcoming barriers to widespread implementation of existing vaccines and developing new vaccines against the most common pathogens causing IBD should be among top priorities for reducing the high mortality rate in young infants. [ABSTRACT FROM AUTHOR]

BackgroundTürkiye confirmed its first case of SARS-CoV-2 on March 11, 2020, coinciding with the declaration of the global COVID-19 pandemic. Subsequently, Türkiye swiftly increased testing capacity and implemented genomic sequencing in 2020. This paper describes Türkiye’s journey of establishing genomic surveillance as a middle-income country with limited prior sequencing capacity and analyses sequencing data from the first two years of the pandemic. We highlight the achievements and challenges experienced and distill globally relevant lessons.MethodsWe tracked the evolution of the COVID-19 pandemic in Türkiye from December 2020 to February 2022 through a timeline and analysed epidemiological, vaccination, and testing data. To investigate the phylodynamic and phylogeographic aspects of SARS-CoV-2, we used Nextstrain to analyze 31,629 high-quality genomes sampled from seven regions nationwide.ResultsTürkiye’s epidemiological curve, mirroring global trends, featured four distinct waves, each coinciding with the emergence and spread of variants of concern (VOCs). Utilizing locally manufactured kits to expand testing capacity and introducing variant-specific quantitative reverse transcription polymerase chain reaction (RT-qPCR) tests developed in partnership with a private company was a strategic advantage in Türkiye, given the scarcity and fragmented global supply chain early in the pandemic. Türkiye contributed more than 86,000 genomic sequences to global databases by February 2022, ensuring that Turkish data was reflected globally. The synergy of variant-specific RT-qPCR kits and genomic sequencing enabled cost-effective monitoring of VOCs. However, data analysis was constrained by a weak sequencing sampling strategy and fragmented data management systems, limiting the application of sequencing data to guide the public health response. Phylodynamic analysis indicated that Türkiye’s geographical position as an international travel hub influenced both national and global transmission of each VOC despite travel restrictions.ConclusionThis paper provides valuable insights into the testing and genomic surveillance systems adopted by Türkiye during the COVID-19 pandemic, proposing important lessons for countries developing national systems. The findings underscore the need for robust testing and sampling strategies, streamlined sample referral, and integrated data management with metadata linkage and data quality crucial for impactful epidemiological analysis. We recommend developing national genomic surveillance strategies to guide sustainable and integrated expansion of capacities built for COVID-19 and to optimize the effective utilization of sequencing data for public health action.

The world has seen unprecedented gains in the global genomic surveillance capacities for pathogens with pandemic and epidemic potential within the last 4 years. To strengthen and sustain the gains made, WHO is working with countries and partners to implement the Global Genomic Surveillance Strategy for Pathogens with Pandemic and Epidemic Potential 2022–2032. A key technical product developed through these multi-agency collaborative efforts is a genomics costing tool (GCT), as sought by many countries. This tool was developed by five institutions – Association of Public Health Laboratories, FIND, The Global Fund to Fight AIDS, Tuberculosis and Malaria, UK Health Security Agency, and the World Health Organization. These institutions developed the GCT to support financial planning and budgeting for SARS-CoV-2 next-generation sequencing activities, including bioinformatic analysis. The tool costs infrastructure, consumables and reagents, human resources, facility and quality management. It is being used by countries to (1) obtain costs of routine sequencing and bioinformatics activities, (2) optimize available resources, and (3) build an investment case for the scale-up or establishment of sequencing and bioinformatics activities. The tool has been validated and is available in English and Russian at https://www.who.int/publications/i/item/9789240090866. This paper aims to highlight the rationale for developing the tool, describe the process of the collaborative effort in developing the tool, and describe the utility of the tool to countries.

The onset of the COVID-19 pandemic triggered a rapid scale-up in the use of genomic surveillance as a pandemic preparedness and response tool. As a result, the number of countries with in-country SARS-CoV-2 genomic sequencing capability increased by 40% from February 2021 to July 2022. The Global Genomic Surveillance Strategy for Pathogens with Pandemic and Epidemic Potential 2022–2032 was launched by the World Health Organization (WHO) in March 2022 to bring greater coherence to ongoing work to strengthen genomic surveillance. This paper describes how WHO’s tailored regional approaches contribute to expanding and further institutionalizing the use of genomic surveillance to guide pandemic preparedness and response measures as part of a harmonized global undertaking. Challenges to achieving this vision include difficulties obtaining sequencing equipment and supplies, shortages of skilled staff, and obstacles to maximizing the utility of genomic data to inform risk assessment and public health action. WHO is helping to overcome these challenges in collaboration with partners. Through its global headquarters, six regional offices, and 153 country offices, WHO is providing support for country-driven efforts to strengthen genomic surveillance in its 194 Member States, with activities reflecting regional specificities. WHO’s regional offices serve as platforms for those countries in their respective regions to share resources and knowledge, engage stakeholders in ways that reflect national and regional priorities, and develop regionally aligned approaches to implementing and sustaining genomic surveillance within public health systems.

This study examines the role of extended family support for parents with children in early and pre-school age, father’s unpaid care work, mother’s employment status, social ties, cultural values, socioeconomic status, and kinship relations from a feminist perspective. A questionnaire composed of a Demographic Information Form, Father Involvement Scale, Extended Family Support Scale, Child’s Day Test, and Trait Anxiety Inventory was used for data collection. The research sample consisted of mothers of 397 children who were aged between 12 and 60 months. A total of 318 mothers were employed in a paid job while 79 were not employed in a paid job. The average age of the children was 36.0 months. It was observed that while all the families live as nuclear families, 17.9% of them lived in a building where their mothers and fathers live as an amalgam family structure (nuclear family living very close to the extended family, for example in the same building but in separate flats), and 3.8% lived in the same house as an extended family structure. The overall percentage of mothers who stated that they receive extended family support was 71.9%. The study also showed that half of the children (51.6%) of the employed mothers were cared for by their grandmothers during the day at least until the children reached two years of age. Furthermore, it was found that fathers’ involvement was limited both in housework and childcare responsibilities. Research findings showed that the social environment in North Cyprus supports familial care as a childcare method. In conclusion, in the North Cyprus sample, the gendered child-rearing role attributed to women continues in the status of grandmothers.

ABSTRACT Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a progressive degeneration of the striatonigral, olivo-ponto-cerebellar, and autonomic systems. Glial cytoplasmic inclusions (GCIs) containing alpha-synuclein represent the hallmark of MSA and are recapitulated in mice expressing alpha-synuclein in oligodendrocytes. To assess if oligodendroglial expression of human wild-type alpha-synuclein in mice (proteolipid promoter, PLP-SYN) could be associated with age-related deficits, PLP-SYN and wild-type mice were assessed for motor function, brain morphometry, striatal levels of dopamine and metabolites, dopaminergic loss, and distribution of GCIs. PLP-SYN displayed age-related impairments on a beam-traversing task. MRI revealed a significantly smaller brain volume in PLP-SYN mice at 12 months, which further decreased at 18 months together with increased volume of ventricles and cortical atrophy. The distribution of GCIs was reminiscent of MSA with a high burden in the basal ganglia. Mild dopaminergic cell loss was associated with decreased dopamine turnover at 18 months. These data indicate that PLP-SYN mice may recapitulate some of the progressive features of MSA and deliver endpoints for the evaluation of therapeutic strategies. Synapse 68:98-106, 2014. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The author discusses the introduction of Bacillus thuringiensis (Bt) cotton in Burkina Faso, India. According to researcher M. Qaim, the heterogeneity in agro-ecological and socioeconomic conditions between regions and among producers lead to differences in outcome of Bt cotton adoption. In the author's view, the possible negative effect of inter-annual variability of agro-ecological conditions and heterogeneity of grower management practices on the financial solvency of poor producers is caused by the high price of Bt seed.

Objective: to explore muscle mitochondria function with respect to age, functional status and nutrition in community-living and recovering hospitalized older subjects. Measurements: subjects were assessed for nutrition, hand-grip strength, 10-meter gait time, a modified timed get-up-and-go test and activities of daily living score (ADL). 31P magnetic resonance spectroscopy (31P MRS) was used to assess the initial rate of post-exercise phosphocreatine recovery (ViPCr) for mitochondrial function evaluation in 25 hospitalized older subjects (86.1 + 5.3 y) and in 25 community-living younger ones (74.5 + 6.2 y). Results: in multiple linear regression, longer time on the get-up-and-go test was independently associated with lower values of ViPCr (p = 0.008). For all subjects and in the 8 patients unable to perform this test, ViPCr was negatively correlated with the ADL score (respectively p < 0.001 and p = 0.025). Conclusion: particularly in hospitalized and frail older subjects, muscle mitochondrial function was related to the global physical functional assessment. [ABSTRACT FROM AUTHOR]

Background: Many studies report that the comprehension of sentences derived by movement of phrases is impaired in agrammatism. However, only few studies have explored the comprehension of sentences that involve a movement of the verb. In several languages, the verb can or should move to the second position of a sentence, creating VSO sentences like 'Yesterday ate the girl a watermelon' from an SVO sentence. Previous studies of comprehension of verb movement either allowed the patients to use a strategy, or used grammaticality judgement tasks, which probably tap different abilities from interpretation tasks. Aims: The present study tested the comprehension of sentences with verb movement to second position in agrammatism using a novel sentence type that prevented participants from employing strategy-based comprehension. Comprehension was tested using sentences with verb--noun homophones and homographs. In general, the choice between the noun and the verb meaning of homophones and homographs relies on the construction of the syntactic structure of the sentence, and the syntactic role of the ambiguous word. In the current study, we used sentences in which the ambiguous word was placed at the object position, such as 'Yesterday caught the bat flies in the garden' (literally transcribed into English). In order to understand whether it is a verb or a noun (whether the bat in this sentence flies, or whether it catches flies), comprehension of the relation between the moved verb and its object is required. Thus, these sentences might shed light on whether individuals with agrammatism can understand verb movement. Methods & Procedures : participants were six Hebrew-speaking individuals with agrammatic aphasia. In Experiment 1 they paraphrased auditorily presented sentences with homophones; in Experiment 2 they read aloud and then paraphrased written sentences with heterophonic homographs. Both experiments also included, in addition to the target sentences with verb movement, matched sentences with the same homographs and homophones that did not include verb movement. Experiment 1 included 51 sentences, Experiment 2 included 48 sentences per participant. Outcomes & Results : The individuals with agrammatic aphasia failed to read and paraphrase the sentences with verb movement. They either took the object to be the verb, read the moved verb incorrectly, said they did not understand the sentence, or said that there were two parts of the sentence that did not connect. Matched sentences with the same homophones and homographs without verb movement were comprehended significantly better. Normal subjects performed correctly in all conditions. Conclusions : Not only is the comprehension of movement of phrases impaired in agrammatism, but also the comprehension of sentences derived by verb movement. [ABSTRACT FROM AUTHOR]

This study examined how phonological information is represented and retrieved, using analysis of naming errors in anomia. We focused on questions that relate to metrical and segmental information, the types of information each of them contains, and whether they are organised in parallel or serially. Nine Hebrew-speaking individuals with anomia due to phonological output deficit named 200 pictures. A detailed analysis of the 208 phonological paraphasias they produced, at the group level and at the individual level, revealed errors preserving only segmental information, errors preserving only metrical information (number of syllables and stress pattern), and errors preserving partial information of both types. There were also errors in the order of segments. The pattern of errors indicates that metrical information and segmental information are accessed in parallel rather than serially, and are merged at a later stage in which the segments are inserted into the word form; and that segmental information includes consonants and vowels, and involves information about their identity as well as about their relative position. Information about the number of syllables seems to be retrieved together with information about the stress pattern. The analysis also showed preservation of phonological principles. [ABSTRACT FROM AUTHOR]

This text deals with a number of interrelated concepts – from something doing to the bare fact of activity, from bare activity to event and change, from change to potential and the production of the new, from production of the new to process as becoming. But process of becoming is also self-creation, and as such is double. It consists of relational and qualitative dimensions, which are also in their turn political and aesthetic, that is aesthetico-political and speculative-pragmatic. Practices we call politics and practices we call art are all integrally aesthetico-political, and every aesthetico-political activity is integrally speculative-pragmatic, and as such can be approached through the concept of techniques of existence. They are inventive of subjective forms in the activist sense – dynamic unities of events unfolding – so they qualify whatever domain in which their creativity is operative as an occurrent art.

Cognitive screening assessments for neurological deficits are critical to the initial assessment of post-stroke patients. However, most measures are not designed for post-stroke patients and in particular not for people with aphasia (PWA), because they rely on language functions. The Cognitive Assessment for Stroke Patients (CASP) is a screening test that can also be administered to PWA, and was recently adapted into Hebrew. The current study aimed to compare the performance of post-stroke patients on the Hebrew versions of the CASP and the Montreal Cognitive Assessment (MoCA). Forty medical records of post-stroke patients were retrospectively examined: Twenty participants without aphasia and 20 PWA. The data included demographics, total CASP and MoCA scores, and scores in specific cognitive domains. Correlations were found between total CASP and MoCA scores, for all participants as well as for each group separately. Comparisons between groups revealed significantly higher performance of the participants without aphasia on the MoCA, but not on the CASP. Clinically, these findings suggest that the Hebrew version of the CASP can be implemented as a formal cognitive screening test for post-stroke patients, including PWA. It can help identifying PWA's cognitive state and differentiate between language and cognitive impairments, hence, contributing in planning targeted treatment.

Kinetoplastids are unicellular eukaryotic flagellated parasites found in a wide range of hosts within the animal and plant kingdoms. They are known to be responsible in humans for African sleeping sickness (Trypanosoma brucei), Chagas disease (Trypanosoma cruzi), and various forms of leishmaniasis (Leishmania spp.), as well as several animal diseases with important economic impact (African trypanosomes, including Trypanosoma congolense). Understanding the biology of these parasites necessarily implies the ability to manipulate their genomes. In this study, we demonstrate that transfection of a ribonucleoprotein complex, composed of recombinant Streptococcus pyogenes Cas9 (SpCas9) and an in vitro-synthesized guide RNA, results in rapid and efficient genetic modifications of trypanosomatids, in marker-free conditions. This approach was successfully developed to inactivate, delete, and mutate candidate genes in various stages of the life cycle of T. brucei and T. congolense, and Leishmania promastigotes. The functionality of SpCas9 in these parasites now provides, to the research community working on these parasites, a rapid and efficient method of genome editing, without requiring plasmid construction and selection by antibiotics but requires only cloning and PCR screening of the clones. Importantly, this approach is adaptable to any wild-type parasite., (© 2024 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.)

This paper reexamines the sources used by N. Fancy and M.H. Green in "Plague and the Fall of Baghdad (1258)" (Medical History, 65/2 (2021), 157-177). Fancy and Green argued that the Arabic and Persian descriptions of the Mongol sieges in Iran and Iraq, and in particular, in the conquest of Baghdad in 1258, indicate that the besieged fortresses and cities were struck by Plague after the Mongol sieges were lifted. This, they suggested, is part of a recurrent pattern of the outbreak of Plague transmitted by the Mongol expansion across Eurasia. Fancy and Green concluded that the primary sources substantiate the theory driven by recent paleogenetic studies indicating that the Mongol conquests of the thirteenth century set the stage for the massive pandemic of the mid-fourteenth century. The link between the Plague outbreak and the Mongol siege of Baghdad relies on three near-contemporaneous historical accounts. However, our re-examination of the sources shows that the main text (in Persian) has been significantly misunderstood, and that the two other texts (in Syriac and Arabic) have been mis-contextualized, and thus not understood properly. They do not support the authors' claim regarding Plague epidemic in Baghdad in 1258, nor do other contemporary and later Arabic texts from Syria and Egypt adduced by them, which we re-examine in detail here. We conclude that there is no evidence for the appearance of Plague during or immediately after the Mongol conquests in the Middle East, certainly not for its transmission by the Mongols.

The current study explored the characteristics of phonological errors of preschool children with DLD (Developmental Language Disorder), distinguishing between typical versus atypical phonological processes in segmental, syllabic and word levels. The analysis included 87 responses of words with phonological errors from a naming test, produced by 13 preschool children with DLD, aged 4;4-6;3 years. These responses included 166 phonological processes, which were classified into typical and atypical processes at the levels of: segments, syllables, and prosodic words. The findings revealed that 70% of the phonological processes were atypical. Furthermore, ten children produced more atypical processes, and there were more atypical than typical processes in segmental and word levels. It is suggested that some children with DLD represent phonological processes that are similar to those that children with speech and sound disorders produce. Therefore, clinically, the results emphasise the importance of analysing the typical and atypical characteristics of phonological errors as part of language assessment.

The long slender bloodstream form Trypanosoma brucei maintains its essential mitochondrial membrane potential (ΔΨm) through the proton-pumping activity of the FoF1-ATP synthase operating in the reverse mode. The ATP that drives this hydrolytic reaction has long been thought to be generated by glycolysis and imported from the cytosol via an ATP/ADP carrier (AAC). Indeed, we demonstrate that AAC is the only carrier that can import ATP into the mitochondrial matrix to power the hydrolytic activity of the FoF1-ATP synthase. However, contrary to expectations, the deletion of AAC has no effect on parasite growth, virulence or levels of ΔΨm. This suggests that ATP is produced by substrate-level phosphorylation pathways in the mitochondrion. Therefore, we knocked out the succinyl-CoA synthetase (SCS) gene, a key mitochondrial enzyme that produces ATP through substrate-level phosphorylation in this parasite. Its absence resulted in changes to the metabolic landscape of the parasite, lowered virulence, and reduced mitochondrial ATP content. Strikingly, these SCS mutant parasites become more dependent on AAC as demonstrated by a 25-fold increase in their sensitivity to the AAC inhibitor, carboxyatractyloside. Since the parasites were able to adapt to the loss of SCS in culture, we also analyzed the more immediate phenotypes that manifest when SCS expression is rapidly suppressed by RNAi. Importantly, when performed under nutrient-limited conditions mimicking various host environments, SCS depletion strongly affected parasite growth and levels of ΔΨm. In totality, the data establish that the long slender bloodstream form mitochondrion is capable of generating ATP via substrate-level phosphorylation pathways., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Taleva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Anomic aphasia is characterized by good comprehension and non-word repetition but poor naming. Two sub-types of deficits might be hypothesized: faulty access to preserved phonological representations or preserved access to impaired representations. Phonological errors may occur only when representations are impaired or in post-lexical deficits (conduction aphasia). We analysed the incidence of phonological naming errors of 30 individuals, 25 with anomic aphasia based on poor naming but good repetition and comprehension, and five with conduction aphasia based on poor naming and poor repetition. Individuals with anomic aphasia produced very few phonological errors compared to individuals with conduction aphasia (0-19.1% versus 42-66%). However, six individuals with anomia produced more than 11% phonological errors, suggesting two patterns of deficit: either impaired lexical representations or impaired access to them. The lack of phonological errors in most individuals with anomic aphasia suggests that access to the phonological output lexicon is semantically, not phonologically driven.

Introduction: Life expectancy has been increasing in recent decades. Therefore, it is important to understand the functional changes during healthy ageing. Most research has mainly focused on one linguistic domain at a time. The current study aimed at investigating whether changes in language performance in healthy ageing occur in some language domains more than in others., Methods: Twenty-three older healthy Hebrew-speaking adults, exhibiting no cognitive decline, were examined on tasks aimed at testing their performance in different language and cognitive domains: lexical retrieval, complementation information, syntax, theory of mind (a domain related to pragmatic aspects of language), and short-term memory. We compared their performance at both the group and the individual levels. Comparisons were made between the performance of the older adults and control data of young adults, and between the older adults' performance in the different linguistic domains. In addition, correlations between the older adults' phonological short-term memory abilities and their performance in various linguistic domains were examined., Results: A decline was found in several linguistic domains among the older adults, while in other domains no decline was found. However, no unequivocal decline in linguistic functioning was found due to relatively large variance in their performance., Conclusion: Not all linguistic domains are equally vulnerable in ageing, and not all older adults are equally affected. The research has both clinical and theoretical implications., (© 2022 S. Karger AG, Basel.)

Lactate is an efficient neuronal energy source, even in presence of glucose. However, the importance of lactate shuttling between astrocytes and neurons for brain activation and function remains to be established. For this purpose, metabolic and hemodynamic responses to sensory stimulation have been measured by functional magnetic resonance spectroscopy and blood oxygen level-dependent (BOLD) fMRI after down-regulation of either neuronal MCT2 or astroglial MCT4 in the rat barrel cortex. Results show that the lactate rise in the barrel cortex upon whisker stimulation is abolished when either transporter is down-regulated. Under the same paradigm, the BOLD response is prevented in all MCT2 down-regulated rats, while about half of the MCT4 down-regulated rats exhibited a loss of the BOLD response. Interestingly, MCT4 down-regulated animals showing no BOLD response were rescued by peripheral lactate infusion, while this treatment had no effect on MCT2 down-regulated rats. When animals were tested in a novel object recognition task, MCT2 down-regulated animals were impaired in the textured but not in the visual version of the task. For MCT4 down-regulated animals, while all animal succeeded in the visual task, half of them exhibited a deficit in the textured task, a similar segregation into two groups as observed for BOLD experiments. Our data demonstrate that lactate shuttling between astrocytes and neurons is essential to give rise to both neurometabolic and neurovascular couplings, which form the basis for the detection of brain activation by functional brain imaging techniques. Moreover, our results establish that this metabolic cooperation is required to sustain behavioral performance based on cortical activation., Competing Interests: The authors declare no competing interest.

Microorganisms must make the right choice for nutrient consumption to adapt to their changing environment. As a consequence, bacteria and yeasts have developed regulatory mechanisms involving nutrient sensing and signaling, known as "catabolite repression," allowing redirection of cell metabolism to maximize the consumption of an energy-efficient carbon source. Here, we report a new mechanism named "metabolic contest" for regulating the use of carbon sources without nutrient sensing and signaling. Trypanosoma brucei is a unicellular eukaryote transmitted by tsetse flies and causing human African trypanosomiasis, or sleeping sickness. We showed that, in contrast to most microorganisms, the insect stages of this parasite developed a preference for glycerol over glucose, with glucose consumption beginning after the depletion of glycerol present in the medium. This "metabolic contest" depends on the combination of 3 conditions: (i) the sequestration of both metabolic pathways in the same subcellular compartment, here in the peroxisomal-related organelles named glycosomes; (ii) the competition for the same substrate, here ATP, with the first enzymatic step of the glycerol and glucose metabolic pathways both being ATP-dependent (glycerol kinase and hexokinase, respectively); and (iii) an unbalanced activity between the competing enzymes, here the glycerol kinase activity being approximately 80-fold higher than the hexokinase activity. As predicted by our model, an approximately 50-fold down-regulation of the GK expression abolished the preference for glycerol over glucose, with glucose and glycerol being metabolized concomitantly. In theory, a metabolic contest could be found in any organism provided that the 3 conditions listed above are met., Competing Interests: The authors have declared that no competing interests exist.

Trypanosoma cruzi, the parasite causing Chagas disease, is a digenetic flagellated protist that infects mammals (including humans) and reduviid insect vectors. Therefore, T. cruzi must colonize different niches in order to complete its life cycle in both hosts. This fact determines the need of adaptations to face challenging environmental cues. The primary environmental challenge, particularly in the insect stages, is poor nutrient availability. In this regard, it is well known that T. cruzi has a flexible metabolism able to rapidly switch from carbohydrates (mainly glucose) to amino acids (mostly proline) consumption. Also established has been the capability of T. cruzi to use glucose and amino acids to support the differentiation process occurring in the insect, from replicative non-infective epimastigotes to non-replicative infective metacyclic trypomastigotes. However, little is known about the possibilities of using externally available and internally stored fatty acids as resources to survive in nutrient-poor environments, and to sustain metacyclogenesis. In this study, we revisit the metabolic fate of fatty acid breakdown in T. cruzi. Herein, we show that during parasite proliferation, the glucose concentration in the medium can regulate the fatty acid metabolism. At the stationary phase, the parasites fully oxidize fatty acids. [U-14C]-palmitate can be taken up from the medium, leading to CO2 production. Additionally, we show that electrons are fed directly to oxidative phosphorylation, and acetyl-CoA is supplied to the tricarboxylic acid (TCA) cycle, which can be used to feed anabolic pathways such as the de novo biosynthesis of fatty acids. Finally, we show as well that the inhibition of fatty acids mobilization into the mitochondrion diminishes the survival to severe starvation, and impairs metacyclogenesis., Competing Interests: The authors have declared that no competing interests exist.

Trypanosoma brucei, a protist responsible for human African trypanosomiasis (sleeping sickness), is transmitted by the tsetse fly where the procyclic forms of the parasite develop in the proline-rich (1-2 mM) and glucose-depleted digestive tract. Proline is essential for the midgut colonization of the parasite in the insect vector, however other carbon sources could be available and used to feed its central metabolism. Here we show that procyclic trypanosomes can consume and metabolize metabolic intermediates, including those excreted from glucose catabolism (succinate, alanine and pyruvate), with the exception of acetate, which is the ultimate end-product excreted by the parasite. Among the tested metabolites, tricarboxylic acid (TCA) cycle intermediates (succinate, malate and α-ketoglutarate) stimulated growth of the parasite in the presence of 2 mM proline. The pathways used for their metabolism were mapped by proton-NMR metabolic profiling and phenotypic analyses of thirteen RNAi and/or null mutants affecting central carbon metabolism. We showed that (i) malate is converted to succinate by both the reducing and oxidative branches of the TCA cycle, which demonstrates that procyclic trypanosomes can use the full TCA cycle, (ii) the enormous rate of α-ketoglutarate consumption (15-times higher than glucose) is possible thanks to the balanced production and consumption of NADH at the substrate level and (iii) α-ketoglutarate is toxic for trypanosomes if not appropriately metabolized as observed for an α-ketoglutarate dehydrogenase null mutant. In addition, epimastigotes produced from procyclics upon overexpression of RBP6 showed a growth defect in the presence of 2 mM proline, which is rescued by α-ketoglutarate, suggesting that physiological amounts of proline are not sufficient per se for the development of trypanosomes in the fly. In conclusion, these data show that trypanosomes can metabolize multiple metabolites, in addition to proline, which allows them to confront challenging environments in the fly., Competing Interests: The authors have declared that no competing interests exist.

The genome of trypanosomatids rearranges by using repeated sequences as platforms for amplification or deletion of genomic segments. These stochastic recombination events have a direct impact on gene dosage and foster the selection of adaptive traits in response to environmental pressure. We provide here such an example by showing that the phosphoenolpyruvate carboxykinase (PEPCK) gene knockout (Δpepck) leads to the selection of a deletion event between two tandemly arranged fumarate reductase (FRDg and FRDm2) genes to produce a chimeric FRDg-m2 gene in the Δpepck∗ cell line. FRDg is expressed in peroxisome-related organelles, named glycosomes, expression of FRDm2 has not been detected to date, and FRDg-m2 is nonfunctional and cytosolic. Re-expression of FRDg significantly impaired growth of the Δpepck∗ cells, but FRD enzyme activity was not required for this negative effect. Instead, glycosomal localization as well as the covalent flavinylation motif of FRD is required to confer growth retardation and intracellular accumulation of reactive oxygen species (ROS). The data suggest that FRDg, similar to Escherichia coli FRD, can generate ROS in a flavin-dependent process by transfer of electrons from NADH to molecular oxygen instead of fumarate when the latter is unavailable, as in the Δpepck background. Hence, growth retardation is interpreted as a consequence of increased production of ROS, and rearrangement of the FRD locus liberates Δpepck∗ cells from this obstacle. Interestingly, intracellular production of ROS has been shown to be required to complete the parasitic cycle in the insect vector, suggesting that FRDg may play a role in this process., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Nuclear Magnetic Resonance (NMR) is an analytical technique extensively used in almost every chemical laboratory for structural identification. This technique provides statistically equivalent signals in spite of using spectrometer with different hardware features and is successfully used for the traceability and quantification of analytes in food samples. Nevertheless, to date only a few internationally agreed guidelines have been reported on the use of NMR for quantitative analysis. The main goal of the present study is to provide a methodological pipeline to assess the reproducibility of NMR data produced for a given matrix by spectrometers from different manufacturers, with different magnetic field strengths, age and hardware configurations. The results have been analyzed through a sequence of chemometric tests to generate a community-built calibration system which was used to verify the performance of the spectrometers and the reproducibility of the predicted sample concentrations., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Nuclear magnetic resonance (NMR) spectroscopy offers the opportunity to measure cerebral metabolite contents in vivo and noninvasively. Thanks to technological developments over the last decade and the increase in magnetic field strength, it is now possible to obtain good resolution spectra in vivo in the rat brain. Neuroenergetics (i.e., the study of brain metabolism) and, especially, metabolic interactions between the different cell types have attracted more and more interest in recent years. Among these metabolic interactions, the existence of a lactate shuttle between neurons and astrocytes is still debated. It is, thus, of great interest to perform functional proton magnetic resonance spectroscopy ( 1 H-MRS) in a rat model of brain activation and monitor lactate. However, the methyl lactate peak overlaps lipid resonance peaks and is difficult to quantify. The protocol described below allows metabolic and lactate fluctuations to be monitored in an activated brain area. Cerebral activation is obtained by whisker stimulation and 1 H-MRS is performed in the corresponding activated barrel cortex, whose area is detected using blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI). All steps are fully described: the choice of anesthetics, coils, and sequences, achieving efficient whisker stimulation directly in the magnet, and data processing.

In the glucose-free environment that is the midgut of the tsetse fly vector, the procyclic form of Trypanosoma brucei primarily uses proline to feed its central carbon and energy metabolism. In these conditions, the parasite needs to produce glucose 6-phosphate (G6P) through gluconeogenesis from metabolism of non-glycolytic carbon source(s). We showed here that two phosphoenolpyruvate-producing enzymes, PEP carboxykinase (PEPCK) and pyruvate phosphate dikinase (PPDK) have a redundant function for the essential gluconeogenesis from proline. Indeed, incorporation of 13C-enriched proline into G6P was abolished in the PEPCK/PPDK null double mutant (Δppdk/Δpepck), but not in the single Δppdk and Δpepck mutant cell lines. The procyclic trypanosome also uses the glycerol conversion pathway to feed gluconeogenesis, since the death of the Δppdk/Δpepck double null mutant in glucose-free conditions is only observed after RNAi-mediated down-regulation of the expression of the glycerol kinase, the first enzyme of the glycerol conversion pathways. Deletion of the gene encoding fructose-1,6-bisphosphatase (Δfbpase), a key gluconeogenic enzyme irreversibly producing fructose 6-phosphate from fructose 1,6-bisphosphate, considerably reduced, but not abolished, incorporation of 13C-enriched proline into G6P. In addition, the Δfbpase cell line is viable in glucose-free conditions, suggesting that an alternative pathway can be used for G6P production in vitro. However, FBPase is essential in vivo, as shown by the incapacity of the Δfbpase null mutant to colonise the fly vector salivary glands, while the parental phenotype is restored in the Δfbpase rescued cell line re-expressing FBPase. The essential role of FBPase for the development of T. brucei in the tsetse was confirmed by taking advantage of an in vitro differentiation assay based on the RNA-binding protein 6 over-expression, in which the procyclic forms differentiate into epimastigote forms but not into mammalian-infective metacyclic parasites. In total, morphology, immunofluorescence and cytometry analyses showed that the differentiation of the epimastigote stages into the metacyclic forms is abolished in the Δfbpase mutant., Competing Interests: The authors have declared that no competing interests exist.

The bloodstream forms of Trypanosoma brucei (BSF), the parasite protist causing sleeping sickness, primarily proliferate in the blood of their mammalian hosts. The skin and adipose tissues were recently identified as additional major sites for parasite development. Glucose was the only carbon source known to be used by bloodstream trypanosomes to feed their central carbon metabolism, however, the metabolic behaviour of extravascular tissue-adapted parasites has not been addressed yet. Since the production of glycerol is an important primary function of adipocytes, we have adapted BSF trypanosomes to a glucose-depleted but glycerol-rich culture medium (CMM&#95;Glyc/GlcNAc) and compared their metabolism and proteome to those of parasites grown in standard glucose-rich conditions (CMM&#95;Glc). BSF were shown to consume 2-folds more oxygen per consumed carbon unit in CMM&#95;Glyc/GlcNAc and were 11.5-times more sensitive to SHAM, a specific inhibitor of the plant-like alternative oxidase (TAO), which is the only mitochondrial terminal oxidase expressed in BSF. This is consistent with (i) the absolute requirement of the mitochondrial respiratory activity to convert glycerol into dihydroxyacetone phosphate, as deduced from the updated metabolic scheme and (ii) with the 1.8-fold increase of the TAO expression level compared to the presence of glucose. Proton NMR analysis of excreted end products from glycerol and glucose metabolism showed that these two carbon sources are metabolised through the same pathways, although the contributions of the acetate and succinate branches are more important in the presence of glycerol than glucose (10.2% versus 3.4% of the excreted end products, respectively). In addition, metabolomic analyses by mass spectrometry showed that, in the absence of glucose, 13C-labelled glycerol was incorporated into hexose phosphates through gluconeogenesis. As expected, RNAi-mediated down-regulation of glycerol kinase expression abolished glycerol metabolism and was lethal for BSF grown in CMM&#95;Glyc/GlcNAc. Interestingly, BSF have adapted their metabolism to grow in CMM&#95;Glyc/GlcNAc by concomitantly increasing their rate of glycerol consumption and decreasing that of glucose. However, the glycerol kinase activity was 7.8-fold lower in CMM&#95;Glyc/GlcNAc, as confirmed by both western blotting and proteomic analyses. This suggests that the huge excess in glycerol kinase that is not absolutely required for glycerol metabolism, might be used for another yet undetermined non-essential function in glucose rich-conditions. Altogether, these data demonstrate that BSF trypanosomes are well-adapted to glycerol-rich conditions that could be encountered by the parasite in extravascular niches, such as the skin and adipose tissues., Competing Interests: The authors have declared that no competing interests exist.

Introduction: The lexical retrieval model describes the process of naming - from the level of an abstract concept representation to the production of the word. Lexical retrieval includes several distinct levels. A deficit in any of these levels causes anomia, a naming deficit, and deficits in different levels cause different types of anomia., Aims: To examine whether the theoretical model can be applied in the clinic. Namely, whether it is possible to identify, for a specific patient, the exact impaired lexical retrieval level, and to show that different patients are impaired in different levels., Methods: The performance of 24 participants with aphasia, with lexical retrieval deficits, were analyzed. The analysis included performance on a naming test - including analysis of error types and of the effects that modulate naming errors. We also analyzed the performance in other language tasks that examine the different levels of lexical retrieval, including tasks that do not involve naming., Results: Different types of anomia were found for the different participants. The various types of anomia are reflected in different sorts of naming errors, in different effects that modulate naming errors, and in different performance patterns in the other language tasks., Conclusions: The theoretical model of lexical retrieval can underpin descriptions of clinical phenomena. The findings support the view that the relations between theory and clinic are bidirectional - theories constitute an anchor for the description of clinical phenomena, and clinical findings can support, or refute, theory., Discussion: The distinction between the different types of anomia is important for choosing the appropriate treatment for each patient.

De novo biosynthesis of lipids is essential for Trypanosoma brucei, a protist responsible for the sleeping sickness. Here, we demonstrate that the ketogenic carbon sources, threonine, acetate and glucose, are precursors for both fatty acid and sterol synthesis, while leucine only contributes to sterol production in the tsetse fly midgut stage of the parasite. Degradation of these carbon sources into lipids was investigated using a combination of reverse genetics and analysis of radio-labelled precursors incorporation into lipids. For instance, (i) deletion of the gene encoding isovaleryl-CoA dehydrogenase, involved in the leucine degradation pathway, abolished leucine incorporation into sterols, and (ii) RNAi-mediated down-regulation of the SCP2-thiolase gene expression abolished incorporation of the three ketogenic carbon sources into sterols. The SCP2-thiolase is part of a unidirectional two-step bridge between the fatty acid precursor, acetyl-CoA, and the precursor of the mevalonate pathway leading to sterol biosynthesis, 3-hydroxy-3-methylglutaryl-CoA. Metabolic flux through this bridge is increased either in the isovaleryl-CoA dehydrogenase null mutant or when the degradation of the ketogenic carbon sources is affected. We also observed a preference for fatty acids synthesis from ketogenic carbon sources, since blocking acetyl-CoA production from both glucose and threonine abolished acetate incorporation into sterols, while incorporation of acetate into fatty acids was increased. Interestingly, the growth of the isovaleryl-CoA dehydrogenase null mutant, but not that of the parental cells, is interrupted in the absence of ketogenic carbon sources, including lipids, which demonstrates the essential role of the mevalonate pathway. We concluded that procyclic trypanosomes have a strong preference for fatty acid versus sterol biosynthesis from ketogenic carbon sources, and as a consequence, that leucine is likely to be the main source, if not the only one, used by trypanosomes in the infected insect vector digestive tract to feed the mevalonate pathway., Competing Interests: The authors have declared that no competing interests exist.

Naming is a complex, multi-level process. It is composed of distinct semantic and phonological levels. Children with naming deficits produce different error types when failing to retrieve the target word. This study explored the error characteristics of children with language impairment compared to those with typical language development. 46 preschool children were tested on a naming test: 16 with language impairment and a naming deficit and 30 with typical language development. The analysis compared types of error in both groups. In a group level, children with language impairment produced different error patterns compared to the control group. Based on naming error analysis and performance on other language tests, two case studies of contrasting profiles suggest different sources for lexical retrieval difficulties in children. The findings reveal differences between the two groups in naming scores and naming errors, and support a qualitative impairment in early development of children with naming deficits. The differing profiles of naming deficits emphasise the importance of including error analysis in the diagnosis.

Adaptation to different nutritional environments is essential for life cycle completion by all Trypanosoma brucei sub-species. In the tsetse fly vector, L-proline is among the most abundant amino acids and is mainly used by the fly for lactation and to fuel flight muscle. The procyclic (insect) stage of T. b. brucei uses L-proline as its main carbon source, relying on an efficient catabolic pathway to convert it to glutamate, and then to succinate, acetate and alanine as the main secreted end products. Here we investigated the essentiality of an undisrupted proline catabolic pathway in T. b. brucei by studying mitochondrial Δ1-pyrroline-5-carboxylate dehydrogenase (TbP5CDH), which catalyzes the irreversible conversion of gamma-glutamate semialdehyde (γGS) into L-glutamate and NADH. In addition, we provided evidence for the absence of a functional proline biosynthetic pathway. TbP5CDH expression is developmentally regulated in the insect stages of the parasite, but absent in bloodstream forms grown in vitro. RNAi down-regulation of TbP5CDH severely affected the growth of procyclic trypanosomes in vitro in the absence of glucose, and altered the metabolic flux when proline was the sole carbon source. Furthermore, TbP5CDH knocked-down cells exhibited alterations in the mitochondrial inner membrane potential (ΔΨm), respiratory control ratio and ATP production. Also, changes in the proline-glutamate oxidative capacity slightly affected the surface expression of the major surface glycoprotein EP-procyclin. In the tsetse, TbP5CDH knocked-down cells were impaired and thus unable to colonize the fly's midgut, probably due to the lack of glucose between bloodmeals. Altogether, our data show that the regulated expression of the proline metabolism pathway in T. b. brucei allows this parasite to adapt to the nutritional environment of the tsetse midgut., Competing Interests: The authors have declared that no competing interests exist.

Pyruvate is a key product of glycolysis that regulates the energy metabolism of cells. In Trypanosoma brucei, the causative agent of sleeping sickness, the fate of pyruvate varies dramatically during the parasite life cycle. In bloodstream forms, pyruvate is mainly excreted, whereas in tsetse fly forms, pyruvate is metabolized in mitochondria yielding additional ATP molecules. The character of the molecular machinery that mediates pyruvate transport across mitochondrial membrane was elusive until the recent discovery of mitochondrial pyruvate carrier (MPC) in yeast and mammals. Here, we characterized pyruvate import into mitochondrion of T. brucei. We identified mpc1 and mpc2 homologs in the T. brucei genome with attributes of MPC protein family and we demonstrated that both proteins are present in the mitochondrial membrane of the parasite. Investigations of mpc1 or mpc2 gene knock-out cells proved that T. brucei MPC1/2 proteins facilitate mitochondrial pyruvate transport. Interestingly, MPC is expressed not only in procyclic trypanosomes with fully activated mitochondria but also in bloodstream trypanosomes in which most of pyruvate is excreted. Moreover, MPC appears to be essential for bloodstream forms, supporting the recently emerging picture that the functions of mitochondria in bloodstream forms are more diverse than it was originally thought., (© 2016 John Wiley & Sons Ltd.)