Suspension culture on microcarriers and as aggregates enables expansion and differentiation of pluripotent stem cells (PSCs).

BACKGROUND AIMS: Human pluripotent stem cells (PSCs) hold a great promise for promoting regenerative medical therapies due to their ability to generate multiple mature cell types and for their high expansion potential. However, cell therapies require large numbers of cells to achieve desired therapeutic effects, and traditional two-dimensional static culture methods cannot meet the required production demand for cellular therapies. One solution to this problem is scaling up expansion of PSCs in bioreactors using culture strategies such as growing cells on microcarriers or as aggregates in suspension culture. METHODS: In this study, we directly compared PSC expansion and quality parameters in microcarrier- and aggregate-cultures grown in single-use vertical-wheel bioreactors. RESULTS: We showed comparable expansion of cells on microcarriers and as aggregates by day 6 with a cell density reaching 2.2 × 106 cells/mL and 1.8 × 106 cells/mL and a fold-expansion of 22- and 18-fold, respectively. PSCs cultured on microcarriers and as aggregates were comparable with parallel two-dimensional cultures and with each other in terms of pluripotency marker expression and retention of other pluripotency characteristics as well as differentiation potential into three germ layers, neural precursor cells and cardiomyocytes. CONCLUSIONS: Our study did not demonstrate a clear advantage between the two three-dimensional methods for the quality parameters assessed. This analysis adds support to the use of bioreactor systems for large scale expansion of PSCs, demonstrating that the cells retain key characteristics of PSCs and differentiation potential in suspension culture.

Failure to deliver therapy by a Riata Lead with internal wire externalization and normal electrical parameters during routine interrogation.

We present a case of failure to deliver a shock by a St. Jude Medical defibrillator involving a Riata lead that was discovered incidentally while the device was attempting to deliver inappropriate therapy. Routine interrogation, including high voltage (HV) impedance, failed to reveal any abnormality. Failure to deliver therapy was confirmed during DFT testing, which revealed extremely low HV impedance only while attempting to deliver therapy. Fluoroscopy indicated moderate externalization of internal wires. This case highlights an under-recognized issue with St. Jude Medical systems, namely the possibility that therapy may not be delivered despite the presence of normal electrical parameters during routine surveillance.

A Multicenter, Randomized, Double-blind, Placebo-controlled Trial of Saccharomyces boulardii in Infants and Children With Acute Diarrhea.

AIM: This study was designed to assess the efficacy and safety of Saccharomyces cerevisiae variant boulardii CNCM I-3799 (S. boulardii CNCM I-3799) in the management of acute diarrhea in children. METHODS: A total of 100 infants and children 3-36 months of age with acute diarrhea received medical care according to the World Health Organization guidelines on the management of acute diarrhea in children and were randomly allocated to the probiotic group (S. boulardii CNCM I-3799 at a daily dose of 5 billion CFU twice daily) or to the placebo group. Infants and children were treated for 5 days and an extended follow-up was planned 1 and 2 months after the end of the treatment period. Primary endpoint was the time of recovery from diarrhea defined as the duration of diarrhea. Other parameters, such as frequency and consistency of stools, associated with the severity of diarrhea episodes were defined as secondary endpoints. RESULTS: The administration of S. boulardii CNCM I-3799 was associated with beneficial effects on duration and severity of diarrhea. The time of recovery from diarrhea was significantly shorter in the probiotic group compared with the placebo group (65.8 ± 12 hours vs. 95.3 ± 17.6 hours, P = 0.0001). Faster remission in the probiotic group was also demonstrated by a shorter time before the first episode of semisolid stool [-23.5 hours, diff (95% CI): -7.99 (-31.49 to -15.51), P = 0.0001] and the faster normalization of stool consistency. S. boulardii CNCM I-3799 was well tolerated. CONCLUSION: S. boulardii CNCM I-3799 supplementation in children with acute diarrhea was shown effective in reducing the duration and severity of diarrhea in infants and children.

Corneal pathology in microphthalmia with linear skin defects syndrome.

PURPOSE: To describe the histopathology of the cornea in microphthalmia with linear streaks (MLS) syndrome. METHODS: Two patients with MLS syndrome underwent penetrating keratoplasty. This study describes the histopathology and investigates immunophenotype of the corneal extracellular matrix by using keratan sulfate and collagen type III antibodies. RESULTS: Clinical examination revealed bilateral sclerocornea and characteristic skin changes. By light microscopy, central corneal stroma in both patients showed vascularization and irregular thick collagen lamellae typical of sclerocornea. In addition, corneal thinning, anterior synechiae, and the absence of the Descemet membrane were noted, which was suggestive of Peters anomaly. Diffuse and intense anti-keratan sulfate staining and minimal anti-collagen type III stromal staining were seen in both corneal buttons. CONCLUSIONS: The cornea in MLS may clinically resemble sclerocornea. Histologic features resemble those previously described in sclerocornea and also seen in anterior segment dysgeneses. Keratan sulfate and collagen type III labeling suggests that the corneal extracellular matrix resembled cornea and not sclera.

Body surface Laplacian electrocardiogram of ventricular depolarization in normal human subjects.

INTRODUCTION: The body surface Laplacian electrocardiogram (ECG) mapping provides a noninvasive means for spatiotemporal mapping of cardiac electrical events. The aim of the present study was to explore the relationship between the Laplacian ECG and the underlying cardiac activities during ventricular depolarization in healthy human subjects. METHODS AND RESULTS: A 95-channel body surface potential ECG was recorded over the anterolateral chest from 11 healthy male subjects. The surface Laplacian (SL) ECG was estimated from the recorded potentials during QRS complex by means of a novel spline SL estimator, as well as by the conventional 5-point SL estimator for comparison purpose. A simulation study was also conducted using a realistic geometry heart-torso model in an attempt to qualitatively interpret the experimental results. For all subjects, more spatial details were observed in the SL ECG maps compared with the potential ECG maps, with spline SL more robust against noise than the 5-point SL. In total, three positive activities (denoted as P1, P2, P3) and four negative activities (denoted as N1, N2, N3, N4) in the spline SL ECG maps were observed during ventricular depolarization. Initial localized P1 and N1 activities were observed in 11 and 8 subjects, respectively. Then, the initial P1 was divided into three positive activities (P1, P2, P3) in 9 subjects. After the appearance of multiple positive activities, three negative activities (N2, N3, N4) appeared in 11, 8, and 9 subjects, respectively. Similar findings were obtained in the computer simulation study. CONCLUSION: The present study demonstrates that the SL ECG provides more spatial details than the potential ECG, and multiple simultaneously active ventricular activities could be revealed in the SL ECG maps. The results suggest that the SL ECG may provide an alternative for noninvasive mapping of cardiac electrical activity.