The bloodstream differentiation - division of Trypanosoma brucei studied using mitochondrial markers

In the bloodstream of its mammalian host, the African trypanosome Trypanosoma brucei undergoes a life cycle stage differentiation from a long, slender form to a short, stumpy form. This involves three known major events: exit from a proliferative cell cycle, morphological change and mitochondrial biogenesis. Previously, models have been proposed accounting for these events (Matthews & Gull 1994a). Refinement of, and discrimination between, these models has been hindered by a lack of stage-regulated antigens useful as markers at the single-cell level. We have now evaluated a variety of cytological markers and applied them to investigate the coordination of phenotypic differentiation and cell cycle arrest. Our studies have focused on the differential expression of the mitochondrial enzyme dihydrolipoamide dehydrogenase relative to the differentiation-division of bloodstream trypanosomes. The results implicate a temporal order of events: commitment, division, phenotypic differentiation

Évaluation des compétences en réanimation en séance de simulation et en milieu de travail : analyse descriptive et comparative de trois spécialités

Background: Simulation-based assessment can complement workplace-based assessment of rare or difficult to assess Entrustable Professional Activities (EPAs). We aimed to compare the use of simulation-based assessment for resuscitation-focused EPAs in three postgraduate medical training programs and describe faculty perceptions of simulation-based assessment. Methods: EPA assessment scores and setting (simulation or workplace) were extracted from 2017-2020 for internal medicine, emergency medicine, and surgical foundations residents at the transition to discipline and foundations of discipline stages. A questionnaire was distributed to clinical competency committee members. Results: Eleven percent of EPA assessments were simulation-based. The proportion of simulation-based assessment did not differ between programs but differed between transition (38%) and foundations (4%) stages within surgical foundations only. Entrustment scores differed between settings in emergency medicine at the transition level only (simulation: 4.82 ± 0.60 workplace: 3.74 ± 0.93). 70% of committee members (n=20) completed the questionnaire. Of those that use simulation-based assessment, 45% interpret them differently than workplace-based assessments. 73% and 100% trust simulation for high-stakes and low-stakes assessment, respectively. Conclusions: The proportion of simulation-based assessment for resuscitation focused EPAs did not differ between three postgraduate medical training programs. Interpretation of simulation-based assessment data between committee members was inconsistent. All respondents trust simulation-based assessment for low-stakes, and the majority for high-stakes assessment. These findings have practical implications for the integration simulation into programs of assessment.Contexte : Pour les activités professionnelles confiables (APC) qui sont rarement observées ou difficiles à évaluer, l’évaluation dans les séances de simulation peut compléter l’évaluation en milieu de travail. Nous avons comparé l’utilisation de l’évaluation lors de simulations pour les APC axées sur la réanimation dans trois programmes de formation médicale postdoctorale et décrit les perceptions de membres du corps professoral concernant cette modalité d’évaluation. Méthodes : Nous avons extrait les scores et le cadre (simulation ou lieu de travail) d’évaluation des APC de 2017 à 2020 pour les résidents en médecine interne, en médecine d’urgence et en fondements chirurgicaux aux étapes de transition vers la discipline et de fondements de la discipline. Un questionnaire a été distribué aux membres du comité des compétences cliniques. Résultats : Onze pour cent des évaluations d’APC étaient faites lors de séances de simulation. Cette proportion était la même pour tous les programmes, mais dans le cadre des fondements chirurgicaux, elle était différente selon qu’il s’agissait de l’étape de transition (38 %) ou de l’étape des fondements (4 %). Les scores de confiance différaient selon le cadre de l’évaluation uniquement pour les résidents en médecine d’urgence à l’étape de la transition (simulation : 4,82 ± 0,60; lieu de travail : 3,74 ± 0,93). Le questionnaire a été rempli par 70 % des membres du comité (n=20). Parmi ceux qui avaient utilisé l’évaluation en séance de simulation, 45 % avaient interprété les données de l’évaluation différemment de la façon dont ils interprètent les données d’évaluation en milieu de travail. Soixante-treize pour cent et 100 % d’entre eux font confiance à la simulation pour les évaluations à enjeux élevés et à faibles enjeux, respectivement. Conclusions : La proportion d’évaluations en séance de simulation pour les APC axées sur la réanimation était la même pour trois programmes de formation médicale postdoctorale. Les membres du comité n’ont pas interprété les données de ce type d’évaluation de manière uniforme. Tous les répondants font confiance à l’évaluation en séance de simulation pour les évaluations à faible enjeu, et la plupart d’entre eux pour les évaluations à enjeu élevé. Ces résultats ont des incidences pratiques sur l’intégration de la simulation dans les programmes d’évaluation

Developmental and Radiobiologic Characteristics of Canine Multinucleated, Osteoclast-Like Cells Generated in Vitro from Canine Bone Marrow

We report here our initial observations on the growth and morphology, and developmental radiosensitivity of giant, multinucleated, osteoclast-like cells (MN-OS} generated through in vitro cultivation of hematopoietic progenitor-enriched canine bone marrow samples. Maximum cell densities of 5.5 x 103 to 6.5 x 103 MN-OS per cm2 of growth area were achieved following 10 to 14 days of culture at 37°C. Acute gamma irradiation of the initial marrow inocula resulted in significant, dose-dependent perturbations of MN-OS formation, growth, and development. Attempts to estimate radiosensitivity of MN-OS progenitors from canine marrow yielded a range of DO values from a low of 212 cGy measured at six days of culture to higher values of 405 to 542 cGy following 10 to 22 days of culture. At the intermediate times of culture (10 to 14 days}, the radiation-induced responses were clearly biphasic, reflecting either (a) the presence of multiple subpopulations of MN-OS progenitors with varying degrees of radiosensitivity or (b) the inherent biphasic nature of MN-OS development involving early progenitor cell proliferation followed by maturation and subsequent fusion. Morphologically, MN-OS generated from irradiated marrow inocula appeared only marginally altered, with alterations expressed largely in a biphasic, dose-dependent fashion in terms of smaller cell size, reduced number of nuclei, increased expression of both surface microprojections, and a unique set of crystalloid cytoplasmic inclusions. Functionally, MN-OS appeared to be impaired by irradiation of marrow progenitors, as evidenced by failure to initiate resorptive attachments to devitalized bone spicules in vitro

The effect of transmucosal 0.2mg/kg Midazolam premedication on dental anxiety, anaesthetic induction and psychological morbidity in children undergoing general anaesthesia for tooth extraction

<b>Background:</b> The project aims were to evaluate the benefit of transmucosal Midazolam 0.2mg/kg pre-medication on anxiety, induction behaviour and psychological morbidity in children undergoing general anaesthesia (GA) extractions. <b>Method:</b> 179 children aged 5-10 years (mean 6.53 years) participated in this randomised, double blind, placebo controlled trial. Ninety children had Midazolam placed in the buccal pouch. Dental anxiety was recorded pre operatively and 48 hours later using a child reported MCDAS-FIS scale. Behaviour at anaesthetic induction was recorded and psychological morbidity was scored by the parent using the Rutter Scale pre-operatively and again one-week later. Subsequent dental attendance was recorded at one, three and six months after GA. <b>Results:</b> Whilst levels of mental anxiety did not reduce overall, the most anxious patients demonstrated a reduction in anxiety after receiving midazolam premedicationmay (p=0.01). Neither induction behaviour nor psychological morbidity improved. Irrespective of group, parents reported less hyperactive (p= 0.002) and more prosocial behaviour (p=0.002) after the procedure:;, older children improved most (p=0.048), Post GA Dental attendance was poor and unrelated to after the procedure and unaffected by premedication. <b>Conclusion:</b> 0.2mg/kg buccal Midazolam provided some evidence for reducing anxiety in the most dentally anxious patients. However, induction behaviour, psychological morbidity and subsequent dental attendance were not found to alter between the premedication groups

Can birth outcome inequality be reduced using targeted caseload midwifery in a deprived diverse inner city population? A retrospective cohort study, London, UK.

Objectives(1) To report maternal and newborn outcomes of pregnant women in areas of social deprivation in inner city London. (2) To compare the effect of caseload midwifery with standard care on maternal and newborn outcomes in this cohort of women.DesignRetrospective observational cohort study.SettingFour council wards (electoral districts) in inner city London, where over 90% of residents are in the two most deprived quintiles of the English Index of Multiple Deprivation (IMD) (2019) and the population is ethnically diverse.ParticipantsAll women booked for antenatal care under Guys and St Thomas' National Health Service Foundation Trust after 11 July 2018 (when the Lambeth Early Action Partnership (LEAP*) caseload midwifery team was implemented) until data collection 18 June 2020. This included 523 pregnancies in the LEAP area, of which 230 were allocated to caseload midwifery, and 8430 pregnancies from other areas.Main outcome measuresTo explore if targeted caseload midwifery (known to reduce preterm birth) will improve important measurable outcomes (preterm birth, mode of birth and newborn outcomes).ResultsThere was a significant reduction in preterm birth rate in women allocated to caseload midwifery, when compared with those who received traditional midwifery care (5.1% vs 11.2%; risk ratio: 0.41; p=0.02; 95% CI 0.18 to 0.86; number needed to treat: 11.9). Caesarean section births were significantly reduced in women allocated to caseload midwifery care, when compared with traditional midwifery care (24.3% vs 38.0%; risk ratio: 0.64: p=0.01; 95% CI 0.47 to 0.90; number needed to treat: 7.4) including emergency caesarean deliveries (15.2% vs 22.5%; risk ratio: 0.59; p=0.03; 95% CI 0.38 to 0.94; number needed to treat: 10) without increase in neonatal unit admission or stillbirth.ConclusionThis study shows that a model of caseload midwifery care implemented in an inner city deprived community improves outcome by significantly reducing preterm birth and birth by caesarean section when compared with traditional care. This data trend suggests that when applied to targeted groups (women in higher IMD quintile and women of diverse ethnicity) that the impact of intervention is greater

Diagnostic accuracy of placental growth factor and ultrasound parameters to predict the small-for-gestational-age infant in women presenting with reduced symphysis-fundus height.

OBJECTIVES: To assess the diagnostic accuracy of placental growth factor (PlGF) and ultrasound parameters to predict delivery of a small-for-gestational-age (SGA) infant in women presenting with reduced symphysis-fundus height (SFH). METHODS: This was a multicenter prospective observational study recruiting 601 women with a singleton pregnancy and reduced SFH between 24 and 37 weeks' gestation across 11 sites in the UK and Canada. Plasma PlGF concentration  95(th) centile and oligohydramnios (amniotic fluid index < 5 cm) were compared as predictors for a SGA infant < 3(rd) customized birth-weight centile and adverse perinatal outcome. Test performance statistics were calculated for all parameters in isolation and in combination. RESULTS: Of the 601 women recruited, 592 were analyzed. For predicting delivery of SGA < 3(rd) centile (n = 78), EFW < 10(th) centile had 58% sensitivity (95% CI, 46-69%) and 93% negative predictive value (NPV) (95% CI, 90-95%), PlGF had 37% sensitivity (95% CI, 27-49%) and 90% NPV (95% CI, 87-93%); in combination, PlGF and EFW < 10(th) centile had 69% sensitivity (95% CI, 55-81%) and 93% NPV (95% CI, 89-96%). The equivalent receiver-operating characteristics (ROC) curve areas were 0.79 (95% CI, 0.74-0.84) for EFW < 10(th) centile, 0.70 (95% CI, 0.63-0.77) for low PlGF and 0.82 (95% CI, 0.77-0.86) in combination. CONCLUSIONS: For women presenting with reduced SFH, ultrasound parameters had modest test performance for predicting delivery of SGA < 3(rd) centile. PlGF performed no better than EFW < 10(th) centile in determining delivery of a SGA infant

Identification of novel seed longevity genes related to oxidative stress and seed coat by genome wide association studies and reverse genetics

[EN] Seed longevity is a polygenic trait of relevance for agriculture and for understanding the effect of environment on the ageing of biological systems. In order to identify novel longevity genes, we have phenotyped the natural variation of 270 ecotypes of the model plant,Arabidopsis thaliana, for natural ageing and for three accelerated ageing methods. Genome-wide analysis, using publicly available single-nucleotide polymorphisms (SNPs) data sets, identified multiple genomic regions associated with variation in seed longevity. Reverse genetics of 20 candidate genes in Columbia ecotype resulted in seven genes positive for seed longevity (PSAD1,SSLEA,SSTPR,DHAR1,CYP86A8,MYB47andSPCH) and five negative ones (RBOHD,RBOHE,RBOHF,KNAT7andSEP3). In this uniform genetic background, natural and accelerated ageing methods provided similar results for seed-longevity in knock-out mutants. The NADPH oxidases (RBOHs), the dehydroascorbate reductase (DHAR1) and the photosystem I subunit (PSAD1) highlight the important role of oxidative stress on seed ageing. The cytochrome P-450 hydroxylase, CYP86A8, and the transcription factors, MYB47, KNAT7 and SEP3, support the protecting role of the seed coat during seed ageing.Ministerio de Ciencia, Innovacion y Universidades, Grant/Award Number: BIO2017-88898-PRenard, J.; Niñoles Rodenes, R.; Martínez-Almonacid, I.; Gayubas, B.; Mateos-Fernández, R.; Bissoli, G.; Bueso Rodenas, E.... (2020). Identification of novel seed longevity genes related to oxidative stress and seed coat by genome wide association studies and reverse genetics. Plant Cell & Environment. 43(10):2523-2539. https://doi.org/10.1111/pce.13822S25232539431