Publications by authors named "Yourka D Tchoukalova"

Objectives: Gain insights into the pathophysiology of idiopathic subglottic stenosis (iSGS) by investigating differences in transcriptome of subglottic mucosal tissue between patients with iSGS and controls, and between tracheal and subglottic tissue within patients.

Methods: RNA sequencing was conducted on biopsied mucosal samples collected from subglottic and tracheal (in-patient control) regions in iSGS patients, and from subglottis in controls. The gene expression differences were validated on a protein level by (1) staining the tissue samples obtained from a second cohort of patients and controls; and (2) in vitro functional assays using primary subglottic epithelial cells from both iSGS patients and healthy donors.

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There are reciprocal interactions between epithelial cells and underlying basement membrane. The resemblance of biomaterials to native basement membrane is thus critical for their success when used to regenerate epithelium-containing organs. Particularly, the use of nanofibers and the incorporation of basement membrane proteins may mimic both biophysical and biochemical properties of basement membrane, respectively.

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Objectives/hypothesis: Develop a patient-specific tissue engineered construct for laryngeal reconstruction following a partial laryngectomy.

Study Design: Bench and animal research.

Methods: A construct made from a porous polyethylene scaffold shaped in a canine-specific configuration and seeded with autologous canine adipose-derived stem cells in fibrin glue was implanted in a canine following a partial laryngectomy.

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Objective: To gain insight into the molecular mechanisms underlying the early stages of vocal fold extracellular matrix (ECM) remodeling after a mid-membranous injury resulting from the use of human amniotic epithelial cells (hAEC), as a novel regenerative medicine cell-based therapy.

Methods: Vocal folds of six female, New Zealand White rabbits were bilaterally injured. Three rabbits had immediate bilateral direct injection of 1 × 10 hAEC in 100 µl of saline solution (hAEC) and three with 100 µl of saline solution (controls, CTR).

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Objective: The study aims to demonstrate the reproducibility and feasibility of creating a hemilaryngeal model with a medialized vocal fold (VF) using 3-dimensional (3D) modeling techniques in both healthy larynges and those affected by cancer.

Study Design: Three-dimensional modeling of human larynges.

Setting: Tertiary academic referral center and regenerative medicine laboratory.

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Introduction: Reconstruction of respiratory epithelium is critical for the fabrication of bioengineered airway implants. Epithelial differentiation is typically achieved using bovine pituitary extract (BPE). Due to the xenogenic nature and undefined composition of BPE, an alternative for human clinical applications, devoid of BPE, must be developed.

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Introduction: The purpose of this study was to compare different decellularization protocols with the conventional detergent enzymatic method (DEM) using continuous agitation.

Methods: The first experiment compared conventional DEM with sonication and lyophilization+freeze-thaw cycles. A second experiment was carried out to compare time-adjusted DEM (2-hour instead of 4-hour incubations with 4% deoxycholate) to decellularization in a bioreactor.

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Objective: Polycystic ovary syndrome (PCOS) is associated with reduced adipose tissue lipolysis that can be rescued by aerobic exercise. We aimed to identify differences in the gene expression of perilipins and associated targets in adipose tissue in women with PCOS before and after exercise.

Design And Methods: We conducted a cross-sectional study in eight women with PCOS and eight women matched for BMI and age with normal cycles.

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Adipose tissue expansion in obesity involves a series of cycles of adipocyte hyperplasia, hypertrophy and hypoplasia due to alterations in adipogenesis, adipocyte cellular metabolism and cell death, respectively. Increased frequency of these cycles may lead to deterioration of adipocyte function and viability, accelerated exhaustion of the adipocyte progenitor pool and extensive adipose tissue remodeling, all leading to impaired expandability of subcutaneous adipose tissue, ectopic lipid accumulation and insulin resistance. Understanding the mechanisms that contribute to adipocyte turnover is thus important.

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Obesity, characterized by excessive adiposity, is a risk factor for many metabolic pathologies, such as type 2 diabetes mellitus (T2DM). Numerous studies have shown that adipose tissue distribution may be a greater predictor of metabolic health. Upper-body fat (visceral and subcutaneous abdominal) is commonly associated with the unfavorable complications of obesity, while lower-body fat (gluteal-femoral) may be protective.

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Impairment of adipogenesis contributes to the development of obesity-related insulin resistance. The current in vitro approaches for its assessment represent crude estimates of the adipogenic potential because of the disruption of the in vivo microenvironment. A novel assessment of in vivo adipogenesis using the incorporation of the stable isotope deuterium ((2)H) into the DNA of isolated adipocytes and stroma-vascular fraction from adipose tissue has been developed.

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Body fat distribution is an important predictor of the metabolic consequences of obesity, but the cellular mechanisms regulating regional fat accumulation are unknown. We assessed the changes in adipocyte size (photomicrographs) and number in response to overfeeding in upper- and lower-body s.c.

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To elucidate cellular mechanisms of sex-related differences in fat distribution, we determined body fat distribution (dual-energy X-ray absorptiometry and single-slice abdominal computed tomography (CT)), adipocyte size, adipocyte number, and proportion of early-differentiated adipocytes (aP2(+)CD68(-)) in the stromovascular fraction (SVF) in the upper and lower body of normal-weight healthy men (n = 12) and premenopausal women (n = 20) (age: 18-49 years, BMI: 18-26 kg/m(2)). Women had more subcutaneous and less visceral fat than men. The proportion of early differentiated adipocytes in the subcutaneous adipose tissue SVF of women was greater than in men (P = 0.

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The size of adipocytes influences their function suggesting a differential responsiveness to intervention. We hypothesized that weight loss in patients with type 2 diabetes mellitus (T2DM) predominantly decreases the size of large and very-large adipocyte subfractions in parallel with beneficial changes in serum adipokines and improved insulin sensitivity. A total of 44 volunteers from the Look Action for Health in Diabetes trial, who lost weight after 1-year of intense lifestyle intervention, were included.

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Intrauterine growth rate is associated with body distribution in adulthood suggesting differential response of fetal fat depots to nutritional modifications. We hypothesize that there is regional differences in fetal adipogenesis, in part, due to depot-specific regulation of the availability of insulin growth factors. In near-term baboon fetuses (n=3-5), the subcutaneous abdominal vs.

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We measured gene expression of paracrine regulators involved in adipocyte differentiation within the stromovascular fraction of abdominal subcutaneous adipose tissue from obese individuals with (n=30) and without (n=18) type 2 diabetes mellitus (T2DM). Despite similar adiposity by design, subjects with T2DM had larger adipocytes (0.92+/-0.

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Background: Both body fat distribution and adipocyte size are associated with metabolic abnormalities.

Objective: We defined the extent to which subcutaneous adipocyte size is related to regional fat mass and to the sizes of adipocytes in other subcutaneous depots independent of adiposity, age, and sex.

Design: Data collected from 188 women and 133 men who were 18-50 y old and who had a body mass index (in kg/m2) of 18 to 50 were analyzed.

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Fat depots vary in function and size. The preadipocytes that fat cells develop from exhibit distinct regional characteristics that persist in culture. Human abdominal subcutaneous cultured preadipocytes undergo more extensive lipid accumulation, higher adipogenic transcription factor expression, and less TNF-alpha-induced apoptosis than omental preadipocytes.

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To understand the significance of the reported depot differences in preadipocyte dynamics, we developed a procedure to identify committed preadipocytes in the stromovascular fraction of fresh human adipose tissue. We documented that adipocyte fatty acid binding protein (aP2) is expressed in human preadipocyte clones capable of replication, indicating that can be used as a marker of committed preadipocytes. Because aP2 expression can be induced in macrophages, stromovascular cells were also stained for the macrophage marker CD68.

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Mean diameters of fat cells from abdominal tissues from 31 volunteers were determined by three methods based on fat cell isolation after collagenase digestion and methylene blue staining. The three methods were direct microscopy (Micro), manual measurement of diameters from digital images by using the public domain NIH Image program (Scion), and automated measurement of diameters from digital images using a customized program developed by Biomedical Imaging Resource at Mayo Clinic (AdCount). There was excellent agreement between the methods' measurement of mean abdominal fat cell diameter (concordance correlation coefficient >0.

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