969 research outputs found

    In Vivo Evaluation of Mechanically Processed Stromal Vascular Fraction in a Chamber Vascularized by an Arteriovenous Shunt

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    Mechanically processed stromal vascular fraction (mSVF) is a promising source for regenerative purposes. To study the in vivo fate of the mSVF, we herein used a vascularized tissue engineering chamber that insulates the target mSVF from the surrounding environment. In contrast to previous models, we propose an arteriovenous (AV) shunt between saphenous vessels in rats without a venous graft. Mechanical SVF was processed from the fat pads of male Sprague Dawley rats, mixed with a fibrin hydrogel and implanted into an inguinal tissue engineering chamber. An arteriovenous shunt was established between saphenous artery and vein. On the contralateral side, an mSVF-fibrin hydrogel mix without vascular axis served as a non-vascularized control. After two and six weeks, rats were sacrificed for further analysis. Mechanical SVF showed significant numbers of mesenchymal stromal cells. Vascularized mSVF explants gained weight over time. Perilipin and CD31 expression were significantly higher in the mSVF explants after six weeks while no difference in DAPI positive cells, collagen deposition and FABP4 expression was observed. Morphologically, no differentiated adipocytes but a dense cell-rich tissue with perilipin-positive cells was found after six weeks. The phosphorylation of ERK1/2 was significantly enhanced after six weeks while Akt activation remained unaltered. Finally, mSVF explants stably expressed and released VEGF, bFGF and TGFb. Vascularized mSVF is able to proliferate and express adipocyte-specific markers. The AV shunt model is a valuable refinement of currently existing AV loop models in the rat which contributes to the fundamental 3R principles of animal research

    Perforated Sigmoid Colon Cancer within an Irreducible Inguinal Hernia: a Case Report

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    A perforated sigmoid colon cancer within an inguinal hernia is extremely rare. This unexpected finding is usually discovered during surgery and causes an unavoidable septic evolution. Here, we describe the case of an 84-year-old man who presented with fever, abdominal distension, and a painful, enlarged, left scrotum. A CT showed a left, incarcerated, inguinal hernia containing a perforated sigmoid adenocarcinoma (which was confirmed by histopathology). The possibility of an irreducible inguinal hernia in association with perforated sigmoid colon cancer should be considered in the array of diagnoses. A pre-operative CT scan would be helpful in facilitating an accurate diagnosis

    Indigenous Case of Disseminated Histoplasmosis, Taiwan

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    We report the first indigenous case of disseminated histoplasmosis in Taiwan diagnosed by histopathology of bone marrow, microbiologic morphology, and PCR assay of the isolated fungus. This case suggests that histoplasmosis should be 1 of the differential diagnoses of opportunistic infections in immunocompromised patients in Taiwan

    Lithium tantalate electro-optical photonic integrated circuits for high volume manufacturing

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    Photonic integrated circuits based on Lithium Niobate have demonstrated the vast capabilities afforded by material with a high Pockels coefficient, allowing linear and high-speed modulators operating at CMOS voltage levels for applications ranging from data-center communications and photonic accelerators for AI. However despite major progress, the industrial adoption of this technology is compounded by the high cost per wafer. Here we overcome this challenge and demonstrate a photonic platform that satisfies the dichotomy of allowing scalable manufacturing at low cost, while at the same time exhibiting equal, and superior properties to those of Lithium Niobate. We demonstrate that it is possible to manufacture low loss photonic integrated circuits using Lithium Tantalate, a material that is already commercially adopted for acoustic filters in 5G and 6G. We show that LiTaO3 posses equally attractive optical properties and can be etched with high precision and negligible residues using DUV lithography, diamond like carbon (DLC) as a hard mask and alkaline wet etching. Using this approach we demonstrate microresonators with an intrinsic cavity linewidth of 26.8 MHz, corresponding to a linear loss of 5.6 dB/m and demonstrate a Mach Zehnder modulator with Vpi L = 4.2 V cm half-wave voltage length product. In comparison to Lithium Niobate, the photonic integrated circuits based on LiTaO3 exhibit a much lower birefringence, allowing high-density circuits and broadband operation over all telecommunication bands (O to L band), exhibit higher photorefractive damage threshold, and lower microwave loss tangent. Moreover, we show that the platform supports generation of soliton microcombs in X-Cut LiTaO3 racetrack microresonator with electronically detectable repetition rate, i.e. 30.1 GHz.Comment: 8 pages, 4 figure

    An Unusual Radiologic Pattern of Cryptogenic Organizing Pneumonia: Diffuse Pulmonary Nodules in a Leukemia Patient

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    The radiological appearance of diffuse discrete pulmonary nodules associated with cryptogenic organizing pneumonia (COP) has been rarely described. We describe a case of COP in 49-year-old woman with acute myeloid leukemia who developed diffuse pulmonary nodules during the second course of induction chemotherapy. The clinical status of the patient and imaging findings suggested the presence of a pulmonary metastasis or infectious disease. A video-assisted thoracoscopic lung biopsy resulted in the unexpected diagnosis of COP as an isolated entity. Steroid therapy led to dramatic improvement of the clinical symptoms and the pulmonary lesions

    Metabolic syndrome and abdominal fat are associated with inflammation, but not with clinical outcomes, in peritoneal dialysis patients

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    BACKGROUND: In the general population, metabolic syndrome (MetS) is correlated with visceral fat and a risk factor for cardiovascular disease (CVD); however, little is known about the significance of abdominal fat and its association with inflammation and medication use in peritoneal dialysis (PD) patients. We investigated the relationship of visceral fat area (VFA) with C-reactive protein (CRP) levels and medication use in PD patients and followed their clinical outcomes. METHODS: In a prospective study from February 2009 to February 2012, we assessed diabetes mellitus (DM) status, clinical and PD-associated characteristics, medication use, CRP levels, components of MetS, and VFA in 183 PD patients. These patients were categorized into 3 groups based on MetS and DM status: non-MetS (group 1, n = 73), MetS (group 2, n = 65), and DM (group 3, n = 45). VFA was evaluated by computed tomography (CT) and corrected for body mass index (BMI). RESULTS: Patients in group 1 had smaller VFAs than patients in groups 2 and 3 (3.2 ± 1.8, 4.6 ± 1.9, and 4.9 ± 2.0 cm(2)/[kg/m(2)], respectively, P < 0.05) and lower CRP levels (0.97 ± 2.31, 1.27 ± 2.57, and 1.11 ± 1.35 mg/dL, respectively, P < 0.05). VFA increased with the number of criteria met for MetS. After adjusting for age, body weight, and sex, CRP and albumin levels functioned as independent positive predictors of VFA; on other hand, the use of renin-angiotensin system blockers was inversely correlated with VFA in PD patients without DM. In the survival analysis, DM patients (group 3) had the poorest survival among the 3 groups, but no significant differences were found between groups 1 and 2. CONCLUSION: This study showed that VFA and MetS are associated with CRP levels but cannot predict survival in PD patients without DM. The complex relationship of nutritional parameters to VFA and MetS may explain these results. The type of antihypertensive medication used was also associated with the VFA. The mechanisms behind these findings warrant further investigation

    A colliding maxillary sinus cancer of adenosquamous carcinoma and small cell neuroendocrine carcinoma - a case report with EGFR copy number analysis

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    <p>Abstract</p> <p>Background</p> <p>Small cell neuroendocrine carcinoma (SNEC) of maxillary sinus is a rare and aggressive malignancy. A tumor with squamous cell carcinoma, adenocarcinoma and SNEC co-existence is extremely rare.</p> <p>Case presentation</p> <p>We present a colliding tumor of squamous cell, adenocarcinoma and SNEC in maxillary sinus. The clinical features, diagnosis and EGFR flourescence in situ hybridization (FISH) study are presented. A 52-year-old female had a 1-month history of progressing left cheek swelling and purulent rhinorrhea. Magnetic resonance imaging showed a tumor involving left maxilla and orbital floor. Excision of tumor was done and the defect was reconstructed with free flap. The pathology revealed a malignant tumor composed of squamous cell carcinoma, adenocarcinoma and SNEC components. EGFR FISH study showed no gene amplification in 3 components of this tumor. The tumor progressed rapidly and the patient expired at 8 months after surgery.</p> <p>Conclusion</p> <p>A colliding tumor of squamous cell, adenocarcinoma and neuroendocrine carcinoma in maxillary sinus was aggressive in behavior and the treatment response was poor due to the complexity of tumor.</p

    Enhanced Differentiation of Three-Gene-Reprogrammed Induced Pluripotent Stem Cells into Adipocytes via Adenoviral-Mediated PGC-1α Overexpression

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    Induced pluripotent stem cells formed by the introduction of only three factors, Oct4/Sox2/Klf4 (3-gene iPSCs), may provide a safer option for stem cell-based therapy than iPSCs conventionally introduced with four-gene iPSCs. Peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) plays an important role during brown fat development. However, the potential roles of PGC-1α in regulating mitochondrial biogenesis and the differentiation of iPSCs are still unclear. Here, we investigated the effects of adenovirus-mediated PGC-1α overexpression in 3-gene iPSCs. PGC-1α overexpression resulted in increased mitochondrial mass, reactive oxygen species production, and oxygen consumption. Microarray-based bioinformatics showed that the gene expression pattern of PGC-1α-overexpressing 3-gene iPSCs resembled the expression pattern observed in adipocytes. Furthermore, PGC-1α overexpression enhanced adipogenic differentiation and the expression of several brown fat markers, including uncoupling protein-1, cytochrome C, and nuclear respiratory factor-1, whereas it inhibited the expression of the white fat marker uncoupling protein-2. Furthermore, PGC-1α overexpression significantly suppressed osteogenic differentiation. These data demonstrate that PGC-1α directs the differentiation of 3-gene iPSCs into adipocyte-like cells with features of brown fat cells. This may provide a therapeutic strategy for the treatment of mitochondrial disorders and obesity
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