Publications by authors named "Francois Marchal"

The origin of difficult birth is still a matter of debate in obstetrics. Recent studies hypothesized that early hominins already experienced obstructed labor even with reduced neonatal head sizes. The aim of this work is to test this hypothesis using an extant obstetrical sample with known delivery outcomes.

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Article Synopsis
  • The study explores how the structure of the femur (thigh bone) and pelvis is coordinated with locomotion among different primate species, including humans, chimps, bonobos, and baboons.
  • It utilizes geometric morphometrics to analyze the relationships and integration of pelvic and femoral morphology, revealing differences in how these species adapt to their modes of locomotion.
  • Results indicate that baboons have strong morphological integration but low morpho-structural integration, while humans display the opposite, suggesting different evolutionary pressures impacting their locomotion and skeletal features.
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Background: Counter-nutation movement is deemed crucial during the management of the birth process. It is a combination of lateral ilia expansion and backward displacement of the promontory resulting from the external rotations of the femurs producing an enlargement of the pelvic inlet. However, since its description by Farabeuf, this mechanism has never been challenged and analyzed in a dynamic finite element study.

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Objective: Although extant nonhuman primates are not habitual bipeds, they are able to walk bipedally from an early age. In humans, children improve their walking skills through developmental processes and learning experience. In nonhuman primates, infants do not routinely experience bipedalism and their musculoskeletal system gradually specializes for other locomotor modes.

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Human infants are born neurologically immature, potentially owing to conflicting selection pressures between bipedal locomotion and encephalization as suggested by the obstetrical dilemma hypothesis. Australopithecines are ideal for investigating this trade-off, having a bipedally adapted pelvis, yet relatively small brains. Our finite-element birth simulations indicate that rotational birth cannot be inferred from bony morphology alone.

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A large variety of disposable face masks have been produced since the onset of the COVID-19 pandemic. Decreased resistance to inspiration improves adherence to the use of the mask; the so called breathability is usually estimated by the measurement of air flow across a section of the tissue under a given pressure difference. We hypothesized that the mask pressure-flow relationship studied in conditions that mimic tidal breathing could allow a more comprehensive characterization of airflow resistance, a major determinant of mask comfort.

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  • A recent review outlines the technical standards and physiological basis of respiratory oscillometry, highlighting its relevance in clinical settings.
  • Oscillometry is noted for its sensitivity in measuring airway resistance and effectiveness in conditions like asthma and COPD, especially when traditional tests are unsuitable.
  • Despite its promise, further research is necessary to establish its clinical utility for diagnosing and monitoring respiratory diseases.
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Objectives: The appearance of sexually dimorphic traits varies depending on the type of bone, age, environmental and genetic factors and is closely linked to skeletal maturation sequence. Subadult sex estimation currently shows inconsistent accuracy and methods do not incorporate indicators of maturation. The goal of this study is to apply the Santos et al.

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Objective: This study aimed to analyze the correlations between maternal size, neonatal size, and gestational variables.

Methods: Our sample comprises 131 mother-infant dyads. We investigated correlations between five neonatal traits (gestational age, birthweight, head, suboccipito-brematic, and abdominal girths), three maternal traits (height, BMI, and uterus height), and three pelvic variables (conjugate, inter-spinous diameters, and sub-pubic angle) using computed tomography pelvimetry.

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Oscillometry (also known as the forced oscillation technique) measures the mechanical properties of the respiratory system (upper and intrathoracic airways, lung tissue and chest wall) during quiet tidal breathing, by the application of an oscillating pressure signal (input or forcing signal), most commonly at the mouth. With increased clinical and research use, it is critical that all technical details of the hardware design, signal processing and analyses, and testing protocols are transparent and clearly reported to allow standardisation, comparison and replication of clinical and research studies. Because of this need, an update of the 2003 European Respiratory Society (ERS) technical standards document was produced by an ERS task force of experts who are active in clinical oscillometry research.

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The 3D imaging technologies have become of paramount importance for example in disciplines such as forensic anthropology and bioarchaeology, where they are being used more and more frequently. There are several new possibilities that they offer; for instance, the easier and faster sharing of data among institutions, the possibility of permanent documentation, or new opportunities of data analysis. An important requirement, however, is whether the data obtained from different scanning devices are comparable and whether the possible varying outputs could affect further analyses, such as the estimation of the biological profile.

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Objectives: A decisional tool was developed to select sub-adult age estimation methods referenced in a centralized database. Through a freely accessible webpage interface, this tool allows users to evaluate how much the sampling and statistical protocols of these referenced methods comply with methodological recommendations published for building and applying methods in forensic anthropology.

Materials And Methods: 261 publications on sub-adult age estimation were collected.

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Objective: The primary objective of this non-randomised phase II study was to evaluate the combination of systemic chemotherapy plus cetuximab after complete cytoreductive surgery (CCS) for treatment of isolated colorectal peritoneal carcinoma (CRPC). This multicentre, prospective phase II clinical trial was conducted in seven national cancer referral centres, however research published during study recruitment indicated cetuximab treatment as ineffective in patients with mutated KRAS genes, leading to an additional exclusion criterion to the current protocol, excluding patients with mutated KRAS genes. This significantly impacted recruitment and the study did not achieve the necessary recruitment of 46 patients.

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Multi-center studies in specific airway resistance have shown significant inter laboratory variability. Comparison of plethysmographic equipment using a lung model easily transportable from one site to another should be of help to international normative studies. A resistor made of parallel capillary tubes - insuring adequate linearity within 1 L/sec - was connected to a glass bottle.

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An index normalizing airway dimension for lung size derived from spirometry was found inversely correlated to lung size in school children born very preterm, indicating larger alveolar volumes draining into comparatively smaller airways. In contrast in children born full term the index was independent of lung size.

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Subadult age estimation should rely on sampling and statistical protocols capturing development variability for more accurate age estimates. In this perspective, measurements were taken on the fifth lumbar vertebrae and/or clavicles of 534 French males and females aged 0-19 years and the ilia of 244 males and females aged 0-12 years. These variables were fitted in nonparametric multivariate adaptive regression splines (MARS) models with 95% prediction intervals (PIs) of age.

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The diversity of approaches and the high number of publications on sub-adult age estimation is a testament to the relevance of this particular area of forensic anthropological research. However, a downside of this diversity is the many methodological, sampling and statistical discrepancies between publications, which can lead to difficulties in method definition, application and comparison. Several authors have published recommendations highlighting standardized methodological parameters that should be respected and clearly appear in the original publications for anthropological methods to be valid.

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Lung hyperinflation may alter the pattern of ventilatory reflexes in chronic respiratory disorders. The aim of the study was to test the effect of continuous positive airway pressure (CPAP) on ventilatory responses to mechanical stimulation of the trachea.

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Deep inspiration (DI) dilates normal airway precontracted with methacholine. The fact that this effect is diminished or absent in asthma could be explained by the presence of bronchial inflammation. The hypothesis was tested that DI induces more relaxation in methacholine induced bronchoconstriction-solely determined by the smooth muscle contraction-than in exercise induced bronchoconstriction, which is contributed to by both smooth muscle contraction and airway wall inflammation.

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A child suspected of exercise-induced laryngeal obstruction and asthma is examined by laryngoscopy and respiratory resistance (Rrs) after exercise challenge. Immediately at exercise cessation, the visualized adduction of the larynx in inspiration is reflected in a paroxystic increase in Rrs. While normal breathing has apparently resumed later on during recovery from exercise, the pattern of Rrs in inspiration is observed to reoccur following a deep breath or swallowing.

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Cough is typically associated with physical activity in children with asthma, but the characteristics of the relationship between cough and exercise has not been established under physiological conditions. The aim of the study was to describe the effect of exercise on the reflex cough response elicited by a single breath of capsaicin in non-asthmatic children. A group of non-asthmatic adults was studied as reference.

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Article Synopsis
  • The study investigates the effectiveness of epinephrine versus arginine vasopressin (AVP) in treating anaphylactic shock (AS) in a rat model, focusing on airway response and arterial pressure.
  • Results showed that while both drugs prolonged survival, epinephrine significantly improved arterial pressure and reduced airway obstruction compared to AVP.
  • The findings suggest that epinephrine is the preferred treatment for managing airway complications during anaphylactic shock, as it outperformed AVP in restoring normal respiratory function.
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Cough and expiration reflex are major lower airway defense mechanisms that have not been studied throughout development in relation with the feeding behavior. To describe airway defense reflexes evoked by mechanical stimulation of the trachea in developing rabbit pups. Sixty one pups were allocated to 3 groups according to their feeding behavior: suckling ( = 22), weanling ( = 21) and weaning ( = 18) group.

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