Spectre phénotypique et génétique d'une cohorte de 74 patients atteints de polymicrogyrie

Les polymicrogyries (PMG) sont des malformations du développement du cortex cérébral les plus fréquentes, hétérogènes et responsables de degré variable d'encéphalopathie, d'épilepsie et de retard psychomoteur. Malgré les progrès de la neuroradiologie et les efforts de classification, les PMG demeurent hétérogènes, la plupart d étiologies indéterminées. La majorité des bases moléculaires et leurs mécanismes neurobiologiques sont alors encore mal élucidés.Les objectifs de notre étude sont de proposer une démarche diagnostic devant un patient présentant une PMG et de proposer une classification opérationnelle pour la recherche moléculaire et la pratique clinique. Nous avons réalisé une étude rétrospective monocentrique (Hôpital Necker Enfants Malades - Paris) de 74 patients atteints de PMG selon les critères habituels à l IRM cérébral. Pour chaque patient ont été recueilli : les données d imagerie avec mention des signes extra corticaux associés; les données cliniques (sexe, âge au diagnostic, examen neurologique, signes associés, et éventuelles étiologies génétiques ou clastiques). Trois groupes de patients ont été constitués en fonction de leur topographie diffuse (n=14), multifocale (n=57) ou focale (n=3). Aucune corrélation n a été montrée entre la topographie et les signes extra corticaux ou le phénotype clinique. En revanche, les diagnostics génétiques ou clastiques, présents chez 1/3 des patients étaient toujours accompagnés de signes caractéristiques évocateurs.Nous proposons une nouvelle classification basée sur les caractéristiques cliniques et sur le mécanisme neurobiologique commun pour simplifier les démarches étiologiques et la recherche moléculaire de ces malformations complexesPARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocSudocFranceF

Autolysis and related proteolysis in Swiss cheese for two Lactobacillus helveticus strains

International audienc

Comparative study of Lactic Acid Bacteria in soy juice fermentation.

Objectifs/ObjectivesThe study aims to improve knowledge over LAB characteristics to ferment a commercial soy juice. Matériels et Méthodes/Materials and methodsFirst 280 strains of LAB from 23 different species of Lactococcus, Streptococcus, Lactobacillus and Leuconostoc genera were tested for their abilities to ferment soy juice containing sucrose, raffinose or stachyose as carbon source and to acidify synthetic media containing sucrose, raffinose or stachyose as unique carbon source. Then, fermented soy juices (FSJ) were produced by 10 h of fermentation (inoculation level 1 %), followed by 14 days of storage at 4 °C. The scents of FSJ were sensorially characterized and FSJ’s primary and secondary metabolites were analyzed. Résultats principaux/Main ResultsWithin 48 h, 39 % of L. lactis strains, 82 % of Lactobacillus strains and all S. thermophilus strains could acidify the synthetic medium with sucrose, as previously described in fermentation patterns of these species. 101 strains representing 18 species could use raffinose and 12 strains representing 6 species could use stachyose. 94 % of the strains that could use sucrose could also ferment soy juice, whose sucrose is the major sugar. Interestingly, 3 strains from species never tested to ferment soy juice, L. kunkeei, L. xiangfangensis and L. pontis revealed abilities to ferment soy juice. Among the 280 strains, 116 strains could acidify soy juice below 6.0 pH units within 10 h. Among the 116 corresponding FSJs, the scents of 48 FSJs were judged as acceptable. The use of sucrose was species-dependent: less residual sucrose was present in FSJs from strains of L. plantarum, L. pentosus, L. lactis, L. delbrueckii and L. coryniformis species compared to S. thermophilus strains. None of the strains used raffinose nor stachyose. S. thermophilus strains produced more lactic acid and less acetic acid than the other strains, in agreement with their homolactic metabolism. Due to acetic acid, FSJs from L. plantarum were more frequently described as ‘sour’. In addition, some strains presented specific traits. For example, CIRM-BIA2115 of L. plantarum produced a floral scent in FSJ likely related to the production of phenylethan-1-ol observed.  ConclusionThe present study is an advance on the knowledge of LAB diversity and their capacity to ferment soy juice. It shows that LAB capacity to use sucrose is important to ferment soy juice and highlights the importance of screening due to the diversity of LAB metabolism

Comparative study of Lactic Acid Bacteria in soy juice fermentation.

Objectifs/ObjectivesThe study aims to improve knowledge over LAB characteristics to ferment a commercial soy juice. Matériels et Méthodes/Materials and methodsFirst 280 strains of LAB from 23 different species of Lactococcus, Streptococcus, Lactobacillus and Leuconostoc genera were tested for their abilities to ferment soy juice containing sucrose, raffinose or stachyose as carbon source and to acidify synthetic media containing sucrose, raffinose or stachyose as unique carbon source. Then, fermented soy juices (FSJ) were produced by 10 h of fermentation (inoculation level 1 %), followed by 14 days of storage at 4 °C. The scents of FSJ were sensorially characterized and FSJ’s primary and secondary metabolites were analyzed. Résultats principaux/Main ResultsWithin 48 h, 39 % of L. lactis strains, 82 % of Lactobacillus strains and all S. thermophilus strains could acidify the synthetic medium with sucrose, as previously described in fermentation patterns of these species. 101 strains representing 18 species could use raffinose and 12 strains representing 6 species could use stachyose. 94 % of the strains that could use sucrose could also ferment soy juice, whose sucrose is the major sugar. Interestingly, 3 strains from species never tested to ferment soy juice, L. kunkeei, L. xiangfangensis and L. pontis revealed abilities to ferment soy juice. Among the 280 strains, 116 strains could acidify soy juice below 6.0 pH units within 10 h. Among the 116 corresponding FSJs, the scents of 48 FSJs were judged as acceptable. The use of sucrose was species-dependent: less residual sucrose was present in FSJs from strains of L. plantarum, L. pentosus, L. lactis, L. delbrueckii and L. coryniformis species compared to S. thermophilus strains. None of the strains used raffinose nor stachyose. S. thermophilus strains produced more lactic acid and less acetic acid than the other strains, in agreement with their homolactic metabolism. Due to acetic acid, FSJs from L. plantarum were more frequently described as ‘sour’. In addition, some strains presented specific traits. For example, CIRM-BIA2115 of L. plantarum produced a floral scent in FSJ likely related to the production of phenylethan-1-ol observed.  ConclusionThe present study is an advance on the knowledge of LAB diversity and their capacity to ferment soy juice. It shows that LAB capacity to use sucrose is important to ferment soy juice and highlights the importance of screening due to the diversity of LAB metabolism

Severe central apnea secondary to cerebellar dysplasia in a child: look past Joubert syndrome

International audienceWe report the case of a female patient aged 12 years referred to our pediatric sleep unit with a history of central sleep apnea associated with transient episodes of tachypnea on polysomnography recordings. The patient was otherwise healthy, with no personal or family medical history, and had a normal physical and neuropsychological examination. Brain magnetic resonance imaging showed signs of cerebellar vermis dysplasia but without the classical features of the molar tooth sign. The rest of the workup (genetic tests, blood tests, cardiac investigations) was normal except for an increased peripheral chemosensitivity to carbon dioxide and oxygen. The patient was successfully treated with bilevel positive airway pressure. This case report highlights the importance of performing brain magnetic resonance imaging in patients with central sleep apnea to study the cerebellum, beyond the brainstem area. Cerebellar malformations can be found even in the absence of any other neurological condition

Strain-to-strain differences within lactic and propionic acid bacteria species strongly impact the properties of cheese-A review

Lactic acid bacteria (LAB) and propionic acid bacteria (PAB) are widely used in the manufacture of cheeses and other fermented dairy products.Bacterial species used as starters are mainly chosen according to their intrinsic properties: the milk acidifying capacity for LAB starters and the aromatizing properties of PAB, for example. Beyond the general characteristics of a bacterial species, many key phenotypic traits determining their interest for dairy applications depend on the strain within a given species. Through some examples, this review illustrates how the choice of a bacterial strain with specific technological characteristics, within a given species of LAB or PAB, can determine the final properties in the end product. This concerns the technological properties of cheeses, such as flavour, texture, and opening formation, and their functional properties, such as inhibition of undesirable microorganisms and health properties. When known, the genetic determinants of the diversity are presented. This review emphasizes the importance of preserving and exploring microbial resources at the intraspecific level, as an unending source of diversity for innovation in food fermentatio

Developmental patterns of fetal fat and corresponding signal on T1-weighted magnetic resonance imaging

Background: Evaluation of subcutaneous fetal fat layer thickness on T1-weighted sequences can be used to predict birth weight. Little is known about normal MR signal patterns of subcutaneous tissue throughout pregnancy. Objective: To establish developmental patterns of subcutaneous fetal fat signal on T1-weighted sequences during the 2nd and 3rd trimesters. Materials and methods: We retrospectively examined T1-weighted images of 110 fetal MRI scans. We measured signal intensity of subcutaneous fat on thighs, buttocks, trunk, nuchal region, chin and scalp. We then calculated the ratios of the obtained values with fetal muscle, amnios and maternal fat signal, and compared the results with those of immunohistochemical examination of adipose tissue extracted from the abdominal wall of fetuses as part of standard autopsy protocol. Results: We included 60 MRI scans in fetuses without intra-uterine growth restriction or macrosomia of non-diabetic mothers (range 23-37 weeks of gestation). Fat T1 intensity of all anatomical regions was low in all fetuses before 26 weeks of gestation. It became more hyperintense with increasing gestational age, in the following order: chin and nuchal region, then buttocks, thighs and trunk, and eventually the scalp at 33 weeks of gestation. After 33 weeks of gestation, all fetal subcutaneous tissues demonstrated overall hyperintense signal. This progression followed the conversion at immunohistochemistry of fetal adipose tissue composition from predominant brown to white adipose cells in 19 fetuses (19-41 weeks of gestation). Conclusion: Between 26 weeks and 33 weeks of gestation, subcutaneous fetal fat signal changed in an orderly pattern from chin to buttocks and scalp. This may reflect the conversion from predominant brown to white adipose tissues in subcutaneous fetal fat

Diversity of the metabolic profiles of a broad range of lactic acid bacteria in soy juice fermentation

This study explores the ability of lactic acid bacteria (LAB) to ferment soy juice. The ability of 276 LAB strains from 25 species to ferment the principal soy carbohydrates, sucrose, raffinose or stachyose was tested in synthetic media and a soy juice. Fermented soy juices (FSJs) were characterized for their odor. Selected FSJs were characterized by targeted metabolomics. All Streptococcus, 83% of Leuconostoc and Lactobacillus and 41% of Lactococcus strains were sucrose-positive, while only 36% of all the LAB strains tested were raffinose-positive and 6% stachyose-positive. Nearly all (97%) the sucrose-positive strains fermented soy juice, indicating that an ability to use sucrose is a good criterion to select strains for soy juice fermentation. Among the most efficient acidifying strains, 46 FSJs had an odor deemed to be acceptable. FSJ composition was dependent on both species and strains: 17/46 strains deglycosylated soy juice isoflavones, the 27 S. thermophilus strains converted a mean 4.4 ± 0.1 g/L of sucrose into 3.0 ± 0.1 g/L of lactic acid versus 5.2 ± 0.1 g/L into 2.2 ± 0.1 g/L for the 18 Lactobacillus and one Lactococcus strains. This study highlights the diversity of the metabolic profiles of LAB strains in soy juice fermentation