Publications by authors named "Jankov R"

Adult stem cells (ASCs) can be cultured with difficulty from most tissues, often requiring chemical or transgenic modification to achieve adequate quantities. We show here that mouse primary fibroblasts, grown in suspension, change from the elongated and flattened morphology observed under standard adherent culture conditions of generating rounded cells with large nuclei and scant cytoplasm and expressing the mesenchymal stem cell (MSC) marker (Sca1; Ly6A) within 24 h. Based on this initial observation, we describe here a suspension culture method that, irrespective of the lineage used, mouse fibroblast or primary human somatic cells (fibroblasts, hepatocytes and keratinocytes), is capable of generating a high yield of cells in spheroid form which display the expression of ASC surface markers, circumventing the anoikis which often occurs at this stage.

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Implementing any new service or program in the health care system is not always straightforward; a multi-stage implementation process is required most of the time. With the advancements in neonatal care and increased survival rates, there has been an increased need for ongoing assessment of hemodynamic stability. At the Children's Hospital of Eastern Ontario and the Ottawa Hospital Neonatal Intensive Care Units (NICUs), University of Ottawa, Canada, Targeted Neonatal Echocardiography service (TnEcho) was successfully established and has led to improvement in the hemodynamic evaluation and decision making in neonatal intensive care.

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Extremely preterm infants develop bronchopulmonary dysplasia (BPD), a chronic lung injury that lacks effective treatment. TSP-1 (thrombospondin-1) is an antiangiogenic protein that activates TGF-β1 (transforming growth factor-β1), a cytokine strongly linked to both experimental and human BPD. ) To examine effects of inhibiting TSP-1-mediated TGF-β1 activation (LSKL [leucine-serine-lysine-leucine]) in neonatal rats with bleomycin-induced lung injury; ) to examine effects of a TSP-1 mimic (ABT-510) on lung morphology; and ) to determine whether TSP-1 and related signaling peptides are increased in lungs of human preterm infants at risk for BPD.

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Circulatory transition after birth presents a critical period whereby the pulmonary vascular bed and right ventricle must adapt to rapidly changing loading conditions. Failure of postnatal transition may present as hypoxemic respiratory failure, with disordered pulmonary and systemic blood flow. In this review, we present the biological and clinical contributors to pathophysiology and present a management framework.

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Premature infants often require mechanical ventilation and oxygen therapy, which can result in bronchopulmonary dysplasia (BPD), characterized by developmental arrest and impaired lung function. Conventional clinical methods for assessing the prenatal lung are not adequate for the detection and assessment of long-term health risks in infants with BPD, highlighting the need for a noninvasive tool for the characterization of lung microstructure and function. Theoretical diffusion models, like the model of xenon exchange (MOXE), interrogate alveolar gas exchange by predicting the uptake of inert hyperpolarized (HP) Xe gas measured with HP Xe magnetic resonance spectroscopy (MRS).

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Purpose: To investigate the dependence of dissolved Xe chemical shift on the fraction of inhaled oxygen, F O , in the lungs of healthy rats.

Methods: The chemical shifts of Xe dissolved in red blood cells, δ , and blood plasma and/or tissue, δ , were measured using MRS in 12 Sprague Dawley rats mechanically ventilated at F O values of 0.14, 0.

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Introduction: Although chronic pulmonary hypertension (cPH) secondary to chronic neonatal lung disease is associated with increased mortality and respiratory and neurodevelopmental morbidities, late diagnosis (typically ≥36 weeks postmenstrual age, PMA) and the use of qualitative echocardiographic diagnostic criterion (flat interventricular septum in systole) remain significant limitations in clinical care. Our objective in this study is to evaluate the utility of relevant quantitative echocardiographic indices to identify cPH in preterm neonates, early in postnatal course and to develop a diagnostic test based on the best combination of markers.

Methods And Analysis: In this ongoing international prospective multicentre observational diagnostic accuracy study, we aim to recruit 350 neonates born <27 weeks PMA and/or birth weight <1000 g and perform echocardiograms in the third week of age and at 32 weeks PMA (early diagnostic assessments, EDA) in addition to the standard diagnostic assessment (SDA) for cPH at 36 weeks PMA.

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During late lung development, alveolar and microvascular development is finalized to enable sufficient gas exchange. Impaired late lung development manifests as bronchopulmonary dysplasia (BPD) in preterm infants. Single-cell RNA sequencing (scRNA-seq) allows for assessment of complex cellular dynamics during biological processes, such as development.

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Objectives: The aim of this study was to use a comprehensive imaging protocol to identify echocardiographic correlations of right and left ventricular size, function, and hemodynamics in neonates with persistent pulmonary hypertension of newborn and describe their relationship with key clinical variables.

Design: Retrospective case-control echocardiography-based study of persistent pulmonary hypertension of newborn.

Setting: A tertiary neonatal ICU in Canada.

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Purpose: To measure the chemical shift of hyperpolarized Xe dissolved in the red blood cells(δ ) of a cohort of rats exposed to hyperoxia and intermittent hypoxia (IH) to mimic human bronchopulmonary dysplasia, and to investigate the effect of xenon-blood distribution time on δ .

Methods: δ was measured from spectra acquired using a chemical shift saturation recovery sequence from 15 Sprague-Dawley rats exposed to hyperoxia-IH and 10 age-matched control rats. Sensitization to the xenon-blood distribution time was achieved by varying the time between saturation pulses, τ.

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Deficient nitric oxide (NO) signaling plays a critical role in the pathogenesis of chronic neonatal pulmonary hypertension (PHT). Physiological NO signaling is regulated by S-nitrosothiols (SNOs), which act both as a reservoir for NO and as a reversible modulator of protein function. We have previously reported that therapy with inhaled NO (iNO) increased peroxynitrite-mediated nitration in the juvenile rat lung, although having minimal reversing effects on vascular remodeling.

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Objective: To characterize the natural history of cardiopulmonary physiology in the first 24 hours after birth.

Study Design: A prospective observational study of healthy newborns was conducted at a large tertiary perinatal center. Echocardiography was performed at <0.

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Purpose: Inhaled nitric oxide (iNO) is a pulmonary vasodilator that is approved for use in term and near-term neonates with hypoxic respiratory failure associated with evidence of pulmonary hypertension. However, it is commonly used in infants and children to treat a variety of other cardiopulmonary diseases associated with pulmonary hypertension and hypoxic respiratory failure. In critically ill children, iNO therapy may be continued for a prolonged period, and this increases the risk for adverse consequences including toxicity and unnecessary costs.

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Bronchopulmonary dysplasia, the most common pulmonary complication of extremely preterm (EPT) birth, has longstanding multiorgan repercussions, with increasing reports of emphysema and cardiac disease in early adulthood. There are currently no clear recommendations pertaining to best practices for optimal multidisciplinary cardiorespiratory follow-up of EPT children. We report the outcomes of a 2-day consensus workshop involving a Canadian panel of 31 multidisciplinary experts with the goal of improvement and standardization of the cardiopulmonary follow-up care of EPT infants (i.

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It is increasingly recognized that the abnormal physiologic consequences of pulmonary hypertension (PH) may contribute to poor cardiopulmonary health in premature babies. Conflicting literature has led to clinical uncertainty, pathological misinterpretation, and variability in treatment approaches among practitioners. There are several disorders with overlapping and interrelated presentations, and other disorders with a similar clinical phenotype but diverse pathophysiological contributors.

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Background/aim: Mammalian target of rapamycin (mTOR) is a pivotal regulator of cell proliferation, survival, and autophagy. Autophagy is increased in adult experimental chronic pulmonary hypertension (PHT), but its contributory role to pulmonary vascular disease remains uncertain and has yet to be explored in the neonatal animal. Notch is a major pro-proliferative pathway activated by mTOR.

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Emerging evidence suggests that long non-coding RNAs (lncRNAs) represent a cellular hub coordinating various cellular processes that are critical in health and disease. Mechanical stress triggers changes in vascular smooth muscle cells (VSMCs) that in turn contribute to pathophysiological changes within the vasculature. We sought to evaluate the role that lncRNAs play in mechanical stretch-induced alterations of human aortic smooth muscle cells (HASMCs).

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Bronchopulmonary dysplasia (BPD) is a chronic lung injury characterized by impaired alveologenesis that may persist into adulthood. Rat models of BPD using varying degrees of hyperoxia to produce injury either cause early mortality or spontaneously recover following removal of the inciting stimulus, thus limiting clinical relevance. We sought to refine an established rat model induced by exposure to 60% O from birth by following hyperoxia with intermittent hypoxia (IH).

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Objectives: To evaluate whether incorporating conventional, tissue Doppler imaging and speckle tracking echocardiography are reliable and can characterize changes in left ventricular (LV) function properly in healthy neonates in the early transitional newborn period.

Study Design: A prospective observational study was conducted in 50 healthy term neonates with a mean ± SD gestational age and birth weight of 39.3 ± 1.

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Chronic neonatal pulmonary hypertension (PHT) frequently results in early death. Systemically administered Rho-kinase (ROCK) inhibitors prevent and reverse chronic PHT in neonatal rats, but at the cost of severe adverse effects, including systemic hypotension and growth restriction. Simvastatin has pleiotropic inhibitory effects on isoprenoid intermediates that may limit activity of RhoA, which signals upstream of ROCK.

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Objectives: Inhaled nitric oxide (iNO) remains the "gold standard" therapy for hypoxemic respiratory failure in newborns. Despite good quality evidence to guide iNO use in this population, we observed considerable practice variation, particularly in timing and rate of weaning. To promote evidence-based practice, we launched an iNO stewardship program in April 2013.

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Systemically-administered bleomycin causes inflammation, arrested lung growth, and pulmonary hypertension (PHT) in the neonatal rat, similar to human infants with severe bronchopulmonary dysplasia (BPD). Leukotrienes (LTs) are inflammatory lipid mediators produced by multiple cell types in the lung. The major LTs, LTB4 and cysteinyl LTs, are suggested to contribute to BPD, but their specific roles remain largely unexplored in experimental models.

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