Temporal mechanisms of myogenic specification in human induced pluripotent stem cells

Understanding the mechanisms of myogenesis in human induced pluripotent stem cells (hiPSCs) is a prerequisite to achieving patient-specific therapy for diseases of skeletal muscle. hiPSCs of different origin show distinctive kinetics and ability to differentiate into myocytes. To address the unique cellular and temporal context of hiPSC differentiation, we perform a longitudinal comparison of the transcriptomic profiles of three hiPSC lines that display differential myogenic specification, one robust and two blunted. We detail temporal differences in mechanisms that lead to robust myogenic specification. We show gene expression signatures of putative cell subpopulations and extracellular matrix components that may support myogenesis. Furthermore, we show that targeted knockdown of ZIC3 at the outset of differentiation leads to improved myogenic specification in blunted hiPSC lines. Our study suggests that β-catenin transcriptional cofactors mediate cross-talk between multiple cellular processes and exogenous cues to facilitate specification of hiPSCs to mesoderm lineage, leading to robust myogenesis.

Introducing infants to referential events: a development study of maternal ostensive marking in French

It is well known that mothers give then infants lessons in conversational competence from an early age. This study considered how maternal gestures and prosody contribute to this developing competence. It examines how mothers use ostensive marking to point out common references at different stages of development. The corpus consisted of longitudinal observations of four mother-infant dyads during free play (infants aged 0;4 to 1;1), at three stages of sensorimotor development (III, IV and V). Four dimensions of ostensive marking were considered: (1) the span of the marked utterance (holistic vs. local); (2) the communication channel used (gestural vs. prosodic); (3) the type of gestural marker (oriented, iconic, conventional, beats); and (4) the type of prosodic marker (emphasis, prosodic cliché, reinforced nuclear stress, focal accent). Although there was no clear change in the patterns of specific types of gestural or prosodic markers, the results showed that mothers adapt their gestures to the infant's processing level. Between stages III and V, they move from holistic to local and from gestural to prosodic marking. Stage IV appears to be an excellent period for observing the transition.

Maintaining and reintroducing referents in French: cognitive constraints and development of narrative skills

Seven- to eleven-year-old French-speaking children and adults told "silent" comic strip stories that differed by the frame display mode, by the explicitness of the links between depicted events, and whether the topic changed on the last frame. The results showed that (a) the character in the last frame was usually referred to as a given, with a definite pronoun when the topic was maintained and a definite noun phrase or a left dislocation when the topic changed; (b) joint display of frames triggered more pronouns and left dislocations, while single-frame display led to more definite noun phrases; and (c) explicit links gave rise to more pronouns. The production conditions manipulated turned out to be a good means of assessing speakers' acquisition of within-discourse referencing expressions and narrative skills: the children gradually refined and adjusted their use of definite expressions and pronouns, whereas the adults more readily used narration-specific devices.

[Propafenone per os in ventricular arrhythmia]

Twenty-one patients presenting ventricular rhythm disorders and admitted to the Intensive Care Unit were treated with oral propafenone at the dosage of 450 to 900 mg/hours. The results of treatment were excellent in 13 cases, average in 2 cases, and nil in 4 cases. Worsening of arrhythmia was observed in 2 cases. Generally the drug was well tolerated, with treatment requiring to be discontinued in 1 case due to gastrointestinal upset and in another case due to broadening of the QRS complex. This study confirms that oral propafenone is well tolerated in ventricular arrhythmias regardless of their etiology.

Feminizing adrenocortical carcinoma in a postmenopausal woman

The successful surgical removal of a feminizing adrenal tumour in a postmenopausal woman is described. Most of these tumours are malignant and the pathological findings and the biological behaviour of the tumour frequently do not correlate, so that a careful follow-up is necessary. In the presence of vaginal bleeding in a postmenopausal woman endometrial carcinoma should be considered. If this has been ruled out and if oestrogens are elevated with low plasma gonadotrophins, a feminizing ovarian or adrenal tumour should be considered.

Adrenal cysts: diagnostic value of "intravenous viscerogram"

Two cases of adrenal pseudocysts are presented, one secondary to the necrosis of an adenoma and the other a hemorrhagic pseudocyst. The diagnosis of these tumors is usually made radiologically owing to the vagueness of symptoms and nonexistent specific laboratory examinations, so that preoperative diagnosis is uncommon. We present a radiologic technique, intravenous viscerogram, which may be useful in the diagnosis of adrenal cysts. This procedure is easy to carry out and has almost no complications for the patient. The classification, clinical findings, and surgical treatment of adrenal cysts are discussed.