Chenxi Ouyang

Mechanical properties of small‐diameter polyurethane vascular grafts reinforced by weft‐knitted tubular fabric

Polyester filament yarns of different Deniers were knitted into tubular fabrics with different densities and thicknesses on a specially designed weft-knitting machine. The developed tubular fabric was used to reinforce polyurethane vascular graft and thus a kind of composite vascular graft was fabricated with a small inner diameter of 4 mm. Tensile properties of the reinforced composite vascular grafts were compared with the control tubular fabric and the pure PU vascular grafts. Elasticity and strength of the reinforced vascular grafts were improved compared with the weft-knitted tubular fabrics. Strength of the reinforced composite vascular grafts was almost 5-10 times of the strength of the pure PU vascular grafts. As the PU content increased in the reinforced composite vascular grafts, the wall thickness of the vascular graft and its strength increased, but the initial modulus of the reinforced composite vascular grafts remained similar to that of the weft-knitted tubular fabric, and the PU content showed little influence on the initial modulus of the reinforced composite vascular grafts. Microporous structure can also be fabricated in the wall of the reinforced composite vascular grafts.

Current Challenges of Cancer Anti-angiogenic Therapy and the Promise of Nanotherapeutics

With growing interest in cancer therapeutics, anti-angiogenic therapy has received considerable attention and is widely administered in several types of human cancers. Nonetheless, this type of therapy may induce multiple signaling pathways compared with cytotoxics and lead to worse outcomes in terms of resistance, invasion, metastasis, and overall survival (OS). Moreover, there are important challenges that limit the translation of promising biomarkers into clinical practice to monitor the efficiency of anti-angiogenic therapy. These pitfalls emphasize the urgent need for discovering alternative angiogenic inhibitors that target multiple angiogenic factors or developing a new drug delivery system for the current inhibitors. The great advantages of nanoparticles are their ability to offer effective routes that target the biological system and regulate different vital processes based on their unique features. Limited studies so far have addressed the effectiveness of nanoparticles in the normalization of the delicate balance between stimulating (pro-angiogenic) and inhibiting (anti-angiogenic) factors. In this review, we shed light on tumor vessels and their microenvironment and consider the current directions of anti-angiogenic and nanotherapeutic treatments. To the best of our knowledge, we consider an important effort in the understanding of anti-angiogenic agents (often a small volume of metals, nonmetallic molecules, or polymers) that can control the growth of new vessels.

Improvement in Cerebral and Ocular Hemodynamics Early after Carotid Endarterectomy in Patients of Severe Carotid Artery Stenosis with or without Contralateral Carotid Occlusion

Purpose. To investigate the alternation in cerebral and ocular blood flow velocity (BFV) in patients of carotid stenosis (CS) with or without contralateral carotid occlusion (CO) early after carotid endarterectomy (CEA). Patients and Methods. Nineteen patients underwent CEA for ≥50% CS. Fourteen patients had the unilateral CS, and five patients had the ipsilateral CS and the contralateral CO. Transcranial Doppler (TCD) and Color Doppler Imaging (CDI) were performed before and early after CEA. Results. In patients with unilateral CS, significant improvements in BFV were observed in anterior cerebral artery (ACA) and middle cerebral artery (MCA) on the ipsilateral side after CEA. In patients of ipsilateral CS and contralateral CO, significant improvements in BFV were observed in the ACA and MCA not only on the ipsilateral side but also on the contralateral side postoperatively. The ipsilateral ophthalmic artery (OA) retrograde flows in two patients were recovered to anterograde direction following CEA. The BFV in short posterior ciliary artery (SPCA) of the ipsilateral side significantly increased postoperatively irrespective of the presence of contralateral CO. Conclusions. CEA improved cerebral anterior circulation hemodynamics especially in patients of unilateral CS and contralateral CO, normalized the OA reverse flow, and increased the blood perfusion of SPCA.

A Primary Primitive Neuroectodermal Tumor Arising from Left Subclavian Vein and Extending along Left Brachiocephalic Vein and Superior Vena Cava into Right Atrium

Primitive neuroectodermal tumor (PNET) is an extremely rare malignancy thought to be derived from fetal neuroectodermal precursor cells. It usually occurs in central and peripheral nervous system or soft tissue and bone, while intravenous or intracavitary PNET is considered as an extremely rare tumor. We reported a case of a 44-year-old woman who presented with the left unilateral facial and neck swelling. Magnetic resonance imaging revealed a tape-shaped solid mass within left subclavian vein, left brachiocephalic vein, superior vena cava, and right atrium; the proximal end proportion occupied almost the entire right atrium with a pedicle flip protruded into the right ventricle. Ultrasonography revealed an irregular hypoechnoic mass arising from the left subclavian vein, which extended along the left brachiocephalic vein and superior vena cava into the right atrium and up to the right ventricle. Positron emission tomography-computed tomography revealed several hypermetabolic thyroid nodules with no evidence of intravenous hyperactive lesion. The patient underwent tumor resection under cardiopulmonary bypass. At 15xa0days postoperatively, total thyroidectomy and resection of the left subclavian vein were simultaneously performed. The patient received chemotherapy and radiotherapy later. Histologically, the neoplasm displayed small, round, blue cells with hyperchromatic nuclei and scant cytoplasm. The neoplastic cells showed a strong immunopositivity for CD99, synaptophysin, CD56, CD57, and friend leukemia integration 1, thus confirming a diagnosis of the PNET. Histopathological examination of the thyroid showed papillary carcinoma. Thus, this PNET had no definitive organ or tissue of origin, which primarily originated from the left subclavian vein with tumor extension along the superior vena cava to the right ventricle.

Carbohydrate Antigens as Potential Biomarkers for the Malignancy in Patients with Idiopathic Deep Venous Thrombosis： A Retrospective Cohort Study

SummaryA variety of biomarkers have been identified in recent prospective and retrospective reports as being potentially predictive of venous thromboembolis (VTE), particularly idiopathic deep venous thrombosis (IDVT). This study identified a serum tumor biomarker for early screening of IDVT. A total of 128 IDVT patients (54 females and 74 males; average age: 50.9±17.4 years) were included. Carcinoembryonic antigen (CEA), ferritin, β2-microglobulin, cancer antigen (CA) 125, CA 15-3, CA 19-9, squamous cell carcinoma antigen (SCC), alpha-fetoprotein (AFP), prostate specific antigen (PSA), free PSA (f-PSA), and beta-human chorionic gonadotropin (β-HCG) in patients with IDVT were detected. Malignancies were histo- or cytopathologically confirmed. Of the 128 IDVT patients, 16 (12.5%) were found to have malignancies. Serum CEA, CA 125, CA 15-3, and CA 19-9 were found to be helpful for detecting malignancies in IDVT patients. Our study revealed a positive association between these markers and tumors in IDVT patients. On the other hand, SCC and AFP were not sensitive enough to be markers for detecting tumors in patients with IDVT. No significant differences were found in positive rates of ferritin and β2-microglobulin between tumor and non-tumor groups, and no significant difference exists in serum levels of ferritin and β2-microglobulin between the two groups. Carbohydrate antigens, CA 15-3 in particular, may be useful for differential diagnosis and prediction of malignancies in patients with IDVT.