Fast and furious: successful survival and resumption of meiosis in immature human oocytes vitrified and warmed using a short protocol.

RESEARCH QUESTION: Can immature oocytes vitrified and warmed using a short protocol survive and resume meiosis? DESIGN: This study examined modifications of oocyte vitrification and warming protocols that reduce the length of exposure to vitrification and warming solutions. In total, 561 germinal vesicles and 218 metaphase I oocytes that were immature at oocyte retrieval were vitrified at room temperature for 2 min. Warming was performed at 37°C for 2 min. Resumption of meiotic activity was evaluated after 24 and 48 h of culture. Two different commercially available vitrification and warming kits were used for comparison. RESULTS: Ninety-five percent of germinal vesicles survived, with no difference observed between the kits. The survival of metaphase I oocytes was, on average, 95.4% and did not differ significantly between the kits. Of the 533 germinal vesicles that survived, 491 converted to metaphase I oocytes (92.1%). After culture for 48 h, 54.4% converted to metaphase II oocytes. In addition, of the 208 metaphase I oocytes that survived warming, 84.1% converted to metaphase II oocytes after 24 h of culture. These maturation rates were similar to those of non-vitrified oocytes. CONCLUSIONS: Vitrification and warming of oocytes at different nuclear maturation stages can be performed with 2 min of exposure to hypertonic solution and 2 min of exposure to hypotonic solution, respectively. This approach reduces exposure of the oocytes to room temperature during dehydration and rehydration. Warming in 0.5M sucrose helps to maintain and support the potential of oocytes to resume nuclear meiotic activity, and conversion from germinal vesicles to metaphase I and metaphase II oocytes.

Poisonings requiring admission to the pediatric intensive care unit: A 5-year review.

BACKGROUND: Poisonings represent a significant number of preventable admissions to the pediatric intensive care unit (PICU), but data about poisonings requiring PICU-level care are limited. OBJECTIVES: To identify the demographics of patients admitted with poisonings and characterize their clinical courses related to their poisoning. METHODS: All poisonings over a 5-year period (2008-2012) at an academic medical center in New England were retrospectively reviewed using electronic medical records in an observational case series. Poisonings were identified using key search terms within an admissions database. RESULTS: There were 273 admissions for poisonings, which represent 8% of total PICU admissions over this time period. The poisonings were unintentional in 148 (54%) cases and intentional in 125 (46%). The vast majority of poisonings occurred in patients either 3 years or below (N = 121, 44%) or 13 years or above (N = 124, 45%). Most (96%) admissions were for less than 48 h and 41% were for less than 24 h. Mean PICU length of stay was 1.2 + 0.7 days. A total of 468 substances were ingested in 54 different drug classes, with analgesics and antidepressants being the most common. Eighty-five (31%) poisonings were polypharmaceutical. The most commonly used therapies were naloxone, activated charcoal, and benzodiazepines. Twenty-seven patients (10%) received mechanical ventilation. There was one fatality, an adolescent with a polypharmacy overdose in a suicide attempt. CONCLUSION: Pediatric poisonings are a significant percentage of admissions to the PICU. The majority of poisonings are non-fatal, require supportive care, close monitoring, and some specific treatment. Drug classes causing poisonings have changed to a higher percentage of opioids in younger patients and atypical antidepressants in adolescents.

Syndecan-4 is essential for development of concentric myocardial hypertrophy via stretch-induced activation of the calcineurin-NFAT pathway.

Sustained pressure overload leads to compensatory myocardial hypertrophy and subsequent heart failure, a leading cause of morbidity and mortality. Further unraveling of the cellular processes involved is essential for development of new treatment strategies. We have investigated the hypothesis that the transmembrane Z-disc proteoglycan syndecan-4, a co-receptor for integrins, connecting extracellular matrix proteins to the cytoskeleton, is an important signal transducer in cardiomyocytes during development of concentric myocardial hypertrophy following pressure overload. Echocardiographic, histochemical and cardiomyocyte size measurements showed that syndecan-4(-/-) mice did not develop concentric myocardial hypertrophy as found in wild-type mice, but rather left ventricular dilatation and dysfunction following pressure overload. Protein and gene expression analyses revealed diminished activation of the central, pro-hypertrophic calcineurin-nuclear factor of activated T-cell (NFAT) signaling pathway. Cardiomyocytes from syndecan-4(-/-)-NFAT-luciferase reporter mice subjected to cyclic mechanical stretch, a hypertrophic stimulus, showed minimal activation of NFAT (1.6-fold) compared to 5.8-fold increase in NFAT-luciferase control cardiomyocytes. Accordingly, overexpression of syndecan-4 or introducing a cell-permeable membrane-targeted syndecan-4 polypeptide (gain of function) activated NFATc4 in vitro. Pull-down experiments demonstrated a direct intracellular syndecan-4-calcineurin interaction. This interaction and activation of NFAT were increased by dephosphorylation of serine 179 (pS179) in syndecan-4. During pressure overload, phosphorylation of syndecan-4 was decreased, and association between syndecan-4, calcineurin and its co-activator calmodulin increased. Moreover, calcineurin dephosphorylated pS179, indicating that calcineurin regulates its own binding and activation. Finally, patients with hypertrophic myocardium due to aortic stenosis had increased syndecan-4 levels with decreased pS179 which was associated with increased NFAT activation. In conclusion, our data show that syndecan-4 is essential for compensatory hypertrophy in the pressure overloaded heart. Specifically, syndecan-4 regulates stretch-induced activation of the calcineurin-NFAT pathway in cardiomyocytes. Thus, our data suggest that manipulation of syndecan-4 may provide an option for therapeutic modulation of calcineurin-NFAT signaling.

A novel myogenic cell line with phenotypic properties of muscle progenitors.

Skeletal myogenesis is a multistep process starting with progenitor cell proliferation, followed by their exit from the cell cycle, differentiation, alignment, and fusion to form multinucleated myotubes, typical of the differentiated muscle tissue. While the molecular players involved in early myogenesis have been extensively characterized, information about the later steps of the process is scanty. Here, we describe a novel myogenic cell line (MYOP7), composed of highly proliferating Sca-1+ muscle precursor cells, which can be induced to terminally differentiate into spontaneously contracting multinucleated myotubes. By performing high-density microarray analysis on these cells, we identified a series of genes, differentially expressed in proliferating vs differentiating conditions, which are candidates to play a major role in the later phase of myogenesis. In addition, we confirmed that the late stages of muscle differentiation are characterized by a marked upregulation of the cellular receptors for the vascular endothelial growth factor.

[Syndrome of supravalvular aortic stenosis (Williams-Beuren syndrome) in association with changes in the kidney and efferent urinary tract]. / Das Syndrom der supravalvulären Aortenstenose (Williams-Beuren-Syndrom) in Verbindung mit Veränderungen der Niere und ableitenden Harnwege.

We investigated the urinary tract in 19 out of 30 children having the Williams-Beuren-Syndrome. 14 of these children showed all signs of the syndrome, whereas 8 children had only the typical cardiological findings without the pathognomonic facies and without major mental retardation. These two different types will be designed as type I and type II respectively. In 12 of the children belonging to type I there were anomalies of the kidneys and the lower urinary tract including 1 child having nephrocalcinosis. The various anomalies were found as single or combined lesions. As for type II there was only 1 child (out of 5) that showed a stenosis of the urethra and at the origin of the ureter in combination with a hydronephrosis. The frequency of anomalies of the urinary tract appears to be very high in type I. However, because of the small number of patients it is impossible to reach statistical significance in comparing the different frequencies within type I and type II. Further investigations are necessary to clarify the problem.