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We have developed a synthetic polymer interface for the long-term self-renewal of human embryonic stem cells (hESCs) in defined media. We successfully cultured hESCs on hydrogel interfaces of aminopropylmethacrylamide (APMAAm) for over 20 passages in chemically-defined mTeSR™ 1 media and demonstrated pluripotency of multiple hESC lines with immunostaining and quantitative RT-PCR studies. Results for hESC proliferation and pluripotency markers were both qualitatively and quantitatively similar to cells cultured on Matrigel™ -coated substrates. Mechanistically, it was resolved that bovine serum albumin (BSA) in the mTeSR™ 1 media was critical for cell adhesion on APMAAm hydrogel interfaces. This study uniquely identified a robust long-term culture surface for the self-renewal of hESCs without the use of biologic coatings (e.g., peptides, proteins, or Matrigel™) in completely chemically-defined media that employed practical culturing techniques amenable to clinical-scale cell expansion.

Modular tissue engineering is a novel approach to assemble tissues with an inherent vascularization. In this article, we evaluated whether endothelialized module-driven vascularization enhances islet engraftment in diabetic rats. Two thousand islets were transplanted in the omental pouch of syngeneic and allogeneic immunosuppressed diabetic recipients as free islets, islets in collagen modules, or islets in endothelialized modules. Transplantation of islets in endothelialized modules significantly increased the vessel density compared with controls. Donor green fluorescent protein-positive endothelial cells (ECs) formed vessels in proximity to transplanted islets; donor vessels connected to host vasculature as the vessels included erythrocytes in their lumens and were supported by host smooth muscle cells by 21 days. Transplantation of 2000 islets reversed diabetes in two of five of syngeneic recipients until 60 days, although there was no apparent benefit to islet function of adding ECs relative to collagen modules without EC. However, there was a trend toward increased viability when islets were implanted in endothelialized modules compared with collagen modules at 21 days. Meanwhile, 2000 islets in allogeneic immunosuppressed recipients lowered blood glucose levels short term, but there was graft failure within 1 week. This study explored the simultaneous transplantation of primary ECs with islets in diabetic recipients. The endothelialized modular approach increased vessel density around transplanted islets. Further modulation (i.e., acceleration) of vessel maturation, is presumed necessary to improve islet engraftment.

To study the outcome of HIV exposed infants in terms of mortality, morbidity, nutritional status and HIV infection status.Retrospective analysis of data on 162 HIV exposed infants registered at Regional Pediatric Center for HIV, Delhi and meeting the inclusion criteria, was done.Median age at presentation was 6 wk. 17.4% mothers were on ART while 44.1% received NVP prophylaxis. 61.7% babies received NVP prophylaxis. Thirty-three percent of infants were symptomatic at presentation. Feeding strategy followed was breast-feeding in 18.7%, replacement feeding 71.6% and mixed feeding 9.7%. At presentation, 50.6% infants were wasted, 48.8% stunted and 39.4% had microcephaly. A progressive increase in proportion of children with under-nutrition, stunting and microcephaly was noted with increasing age at presentation. Of the enrolled infants, 81 (50%) were alive and under follow-up. Among these, HIV infection was excluded in 65 infants (80.2% of those alive, 40.1% of the cohort). Thirty-four (21%) infants died and 47 (29%) were lost to follow-up. HIV infection was diagnosed in 24 (14.8%, 14 definite, 10 presumed). Of these 13 were alive and on ART, while 11 died. HIV status was not ascertained for the infants lost to follow-up and 23 infants who died.HIV infection is being under-diagnosed during pregnancy. Exposed infants have a high mortality and high prevalence of malnutrition. There is an urgent need for standardizing care of exposed infants to promote follow-up and prevent mortality by offering feeding counseling and ensuring early infection detection.

Regenerative therapy for heart failure remains a significantly unmet need in the global medical community. One of the leading causes of heart failure is myocardial infarction (MI), which occurs when the blood supply to a part of the heart is interrupted, causing a loss of cardiac muscle and its replacement with noncontractile scar. Over time, this results in a process of remodeling that leads to left ventricular (LV) dilation and LV dysfunction. Novel approaches to the treatment of this condition are needed to improve the quality of life and the survival of patients who suffer from post-MI LV dysfunction and congestive heart failure (CHF). It has been proposed that, of these treatment options, transplantation of stem cells may significantly improve regional contractile and LV function, and have the best chance of improving the clinical outcome. However, most stem cell transplantation studies have yielded modest results, with either necrotic/apoptotic loss or displacement by the heart's contractions—a universal result for the vast majority of donor cells within days of transplantation. Collectively, these observations suggest that the success of cell transplantation for cardiac tissue regeneration will hinge upon enhanced cell survival, subsequent promotion of their functional integration into existing tissue, and temporal expansion in transplant size. Accordingly, biomaterials are now being explored to address these issues, creating prosurvival systems for stem cell transplantation composed of natural, synthetic, and biosynthetic hybrid materials.

Capillary condensation is employed to probe the solid-liquid interfacial energy in electrowetting on dielectric. The height of an annular water meniscus formed via capillary condensation inside the surface force apparatus is measured as a function of the potential applied across the meniscus and the dielectric stack where the meniscus is formed. According to the Kelvin equation, a decrease in the solid-liquid interfacial energy at constant temperature and relative humidity should lead to an increase in the meniscus height. Our experimental results on nanometer-sized meniscus are in agreement with the work of Mugele [J. Phys.: Condens. Matter 2007, 19, 375112] and unequivocally demonstrate that the real contact angle (or the solid-liquid interfacial energy) remains unaltered in electrowetting on dielectric.

Modular tissue engineering is a novel microscale approach that aims to assemble tissue constructs with inherent vascularization. We transplanted endothelialized modules (sub-millimeter-sized collagen gel cylinders covered with human umbilical vein endothelial cell [HUVEC] on the outside surface) in the omental pouch of nude rats to characterize remodeling of the collagen gels and the fate of the transplanted HUVEC. Endothelialized modules randomly assembled in vivo to form channels among individual modules that persisted for at least 14 days. Transplanted HUVEC migrated and formed primitive vessels in these channels; however, host inflammation limited HUVEC survival beyond 3 days. Temporary depletion of peritoneal macrophages (by treatment with clodronate liposomes) prolonged the survival of HUVEC-derived vessels to 7 days, and some vessels appeared to be perfused with host erythrocytes and invested with host vascular cells (either rat von Willebrand factor or smooth muscle alpha-actin-positive cells). Despite treatment, HUVEC were presumed to be still subject to immune rejection. The presence of primitive HUVEC-derived vessels is encouraging in this first in vivo study of the modular approach, in a partially immune-compromised animal model. It suggests that with appropriate attention to the host response to transplanted endothelial cells and improved vessel survival, cells that would be embedded in modules could be adequately perfused.

Congenital cystic eye is a rare cause of cystic orbital lesion. The condition is recognized at birth as a large orbital mass in place of a normal eye. Only 29 cases have been reported previously. We report a case of unilateral congenital cystic eye with multiple brain anomalies in the form of agenesis of corpus callosum and grey matter heterotopias. In this case report we highlight the MRI features of this entity, which have not been described previously in the literature.

Massive subchorionic hematoma is a large maternal blood clot, which separates the chorionic plate from the villous chorion [Kojima K, et al: Fetal Diagn Ther 2001;16:57–60]. It is an uncommon condition associated with poor perinatal prognosis and intrauterine growth retardation [Tan WH, et al: Fetal Diagn Ther 1997;76:381–383, Nishijima K, et al: Fetal Diagn Ther 2005;20:23–26]. Ultrasound may not be able to differentiate this condition from other placental abnormalities [Kojima K, et al: Fetal Diagn Ther 2001;16:57–60]. We report a case of massive subchorionic hematoma where the antenatal diagnosis was made on MRI.

This brief offers a circuit theoretic explanation of the pseudolumping technique that uses the method of characteristics for analyzing lossy transmission lines. A matrix-operator based error analysis is presented in the frequency domain, which can be used to define the validity of the approach within some error bounds and to efficiently arrive at the order of "lumping" in terms of the line parameters.

The design of system level interconnects to meet signal integrity objectives is a challenging problem. This paper presents moment based techniques for optimal termination of transmission lines. Since obtaining moments of a circuit has been shown to be a computationally efficient task, this method provides a means to account for the effects of loading conditions along the line, loss in the line, input signal rise-time, and different net topologies into an efficient design tool. No iterative time-domain analyses are required and since the technique uses the first few moments of the exact distributed model of a transmission line net, no pre-processing steps are involved. All these factors make this methodology conducive for integration into a CAD tool for design optimization.

Electronic system design requires simulating combinations of lossy, low-loss, frequency dependent, and coupled transmission lines. Accuracy and efficiency considerations would suggest the use of different models and analyses for the various types of interconnects. Toward this goal this paper presents an efficient methodology for characterizing transmission line models into solution domains. Specifically, given an acceptable percentage modeling error, analysis domains are established for automatic model selection between method of characteristics and a lumped modeling approach. >

A renal tumor in a 14-month- old child, who was initially diagnosed as mesoblastic nephroma, but on review post surgery was diagnosed as hyper-differentiated metanephric stromal tumor, with its excellent prognostic outcome. An attempt is made to document imaging features that may enable one to suspect this rare condition. The literature is reviewed with emphasis on its distinction from its look-alikes in the pediatric age group.

The Elmore delay is an extremely popular delay metric, particularly for RC tree analysis. The widespread usage of this metric is mainly attributable to it being the most accurate delay measure that is a simple analytical function of the circuit parameters. The only drawbacks to this delay metric are the uncertainty as to whether it is an optimistic or a pessimistic estimate, and the restriction to step response delay estimation. In this paper, we prove that the Elmore delay is an absolute upper bound on the 50% delay of an RC tree response. Moreover, we prove that this bound holds for input signals other than steps, and that the actual delay asymptotically approaches the Elmore delay as the input signal rise time increases. A lower bound on the delay is also developed using the Elmore delay and the second moment of the impulse response. The utility of this bound is for understanding the accuracy and the limitations of the Elmore delay metric as we use it for design automation.