The development of a novel artificial heart valve with outstanding durability and safety has remained a challenge since the first mechanical heart valve entered the market 65 years ago. Recent progress in high-molecular compounds opened new horizons in overcoming major drawbacks of mechanical and tissue heart valves (dysfunction and failure, tissue degradation, calcification, high immunogenic potential, and high risk of thrombosis), providing new insights into the development of an ideal artificial heart valve. Polymeric heart valves can best mimic the tissue-level mechanical behavior of the native valves. This review summarizes the evolution of polymeric heart valves and the state-of-the-art approaches to their development, fabrication, and manufacturing. The review discusses the biocompatibility and durability testing of previously investigated polymeric materials and presents the most recent developments, including the first human clinical trials of LifePolymer. New promising functional polymers, nanocomposite biomaterials, and valve designs are discussed in terms of their potential application in the development of an ideal polymeric heart valve. The superiority and inferiority of nanocomposite and hybrid materials to non-modified polymers are reported. The review proposes several concepts potentially suitable to address the above-mentioned challenges arising in the R&D of polymeric heart valves from the properties, structure, and surface of polymeric materials. Additive manufacturing, nanotechnology, anisotropy control, machine learning, and advanced modeling tools have given the green light to set new directions for polymeric heart valves.
Extracorporeal partial nephrectomy under pharmaco-cold ischemia without ureter intersection with orthotopic replantation of renal vessels for RCC is a relatively safe organ-sparing treatment. It provides resection of large tumors with any location under prolonged cold ischemia without ureter intersection.
The standards of treatment for metastatic renal cell carcinoma (mRCC) have changed significantly from unsuccessful attempts of radiation and cytostatic therapy to the encouraging results of targeted therapy and specific immunotherapy. Sunitinib has got into the practice in 2006, and now it`s one of the most studied and approved. Sunitinib is one of the first oral targeted drugs for RCC. It affects such receptors as VEGFR1, 2, 3; PDGFR, FGFR, c-KIT, and RET, which take part in the pathologic angiogenesis, tumor growth, and metastasizing. Moreover, sunitinib stimulates the growth and development of lymphatic vessels, that deliver immunocytes to the tumor. The advantage of sunitinib over non-specific immunotherapy has been proven by Motzer et al. The randomized trials COMPARZ, RECORD-3, and SWITCH have confirmed that sunitinib is more effective than several targeted drugs (pazopanib, everolimus, and sorafenib respectively) as the first line of treatment for mRCC. The randomized trial of the 3rd phase CARMENA has demonstrated the importance of sunitinib monotherapy for mRCC of intermediate and poor prognosis. In general, sunitinib has been proven to be an effective first-line drug for mRCC, as it`s evidenced in the comprehensive metaanalysis of real-world data and randomized controlled trials published between 2000 and 2017. Nowadays, despite the success of the immunotherapeutic direction, tyrosine kinase inhibitors, and particularly sunitinib, rightfully remain the standard for mRCC of favourable prognosis, the treatment option for worse prognosis in case of contraindications for other methods of therapy, and it` s also used in subsequent therapy lines.
Purpose. The research goal comprises primary analysis of CT examinations results and their interpretation by comparing with the data already available in the literature.Material and methods. During the period from April 17, 2020 to May 18, 2020, 830 chest CT scans were performed and results of 123 CDs with CT scans made by other institutions were interpreted. Follow-up examinations were carried out every 3–4 days or when clinical presentation changed. At the primary stage, we have analysed in a more detail way a group of 69 patients, who were diagnosed with CT-3 or CT-4 volume of lung damage at least once during hospitalization. The patients underwent PCR analysis three times during hospitalization. Among 69 patients, 34 patients had a positive PCR test at least once, the remaining 35 patients had a clinic, corresponding with this disease.Results. At the initial examination, ground-glass opacity prevailed, as it was observed in 44 cases (64%), and lung tissue consolidation was observed in 25 cases (36%) in a group of 69 patients. When comparing the two groups, the average age of the patients with consolidation changes was statistically significantly lower than one of the group where ground-glass opacity prevailed – 51.7 and 59.4 years, respectively (p = 0.01) In the group of patients with pulmonary tissue consolidation, there were fewer concomitant diseases, fatal outcomes, positive PCR test results, a shorter hospitalization period, and fewer cases of tocilizumab administration were noted. At the initial examination the average percentage of pulmonary parenchyma involvement in the group of patients with lung tissue consolidation was higher (63.3%; p = 0.04), follow-up examinations showed c statistically significantly lower average values of the increase in the percentage of involvement of the parenchyma, which acquired negative values after the third CT scan (8.3 after the 2nd CT and −5.2 after the 3rd CT versus 18.5 and 3 in the GGO glass group; p = 0.02 and 0.03, respectively). No visible differences in CT between the period from the onset of the disease and the predominant symptom in CT were revealed. Meanwhile, on the 5th day (the day of the check-up CT examination) the largest number of patients was determined in both groups.Conclusion. An analysis of our experience during the first month of operation of Covid-19 Hospital is presented. According to our data, the appearance of consolidation at the initial CT examination is probably not related to the period, when the disease has been in progress, and may be associated with a more favorable course of the process.
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