The Structure of the Ladder Insertion-Elimination Lie algebra

We continue our investigation into the insertion-elimination Lie algebra of Feynman graphs in the ladder case, emphasizing the structure of this Lie algebra relevant for future applications in the study of Dyson-Schwinger equations. We work out the relation of this Lie algebra to some classical infinite dimensional Lie algebra and we determine its cohomology.Comment: 24 pages, LaTex, typos correcte

A New Algorithm to Analyze the Video Data of Cell Contractions in Microfluidic Platforms

Проблематика. Одним из быстро развивающихся направлений в науке является тканевая инженерия с использованием технологии “лаборатория на микрочипе”. Для оценки механических сокращений клеток используются оптическая микроскопия и анализ видеоданных. Однако известные методы регистрируют только факт сокращения клеток и существенно искажают форму и амплитуду полезного сигнала. Поэтому задачи корректного количественного анализа таких видеоизображений являются актуальными. Цель. Целью работы является разработка алгоритма анализа видеоданных механических сокращений кардиомиоцитов на микрочипе для определения их функциональных и структурных свойств на тканевом уровне. Методика реализации. Разработанный алгоритм анализа видеоизображений реализован программным кодом Matlab 2016. Для апробации предложенного метода были проанализированы данные о сокращения клеток кардиомиоцитов, выращенных в микрочипе. Исследовались три группы клеток: выращенные без стимуляции, а также клетки, которые стимулировались электрическими полями 5 и 25 В/см. Форма стимулирующих импульсов – прямоугольная, частота – 1 Гц. Результаты. Предложенный алгоритм анализа видеоданных, позволяет оценить скорость сокращения клеток в микрометрах за секунду. Кроме того, он позволяет разложить механические колебания клеток на компоненты. Алгоритм использовался для оценки изменения скорости сокращения кардиомиоцитов в зависимости от интенсивности напряжения и частоты возбуждения. Выводы. Предложенный метод анализа видеоданных сокращений клеток кардиомиоцитов на микрочипе не требует каких-либо вспомогательных биомаркеров или сред. Анализ видеоизображений позволяет оценить амплитуду и скорость колебаний, форму сигнала, пространственно- неоднородное распределение механической активности клеток. Показано, что импульсное электрическое поле в диапазоне 5–25 В/см на частоте 1 Гц при культивировании клеток оказывает отрицательное влияние на сократительную способность кардиомиоцитов

First Experience in Management of Coronavirus Disease 2019 (COVID-19) in Kidney Transplant Patient – Case Report

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has recently emerged in the world. There are limited data describing the clinical progression of COVID-19 in transplanted patients. In the general population, clinical presentation ranges from asymptomatic infection to severe pneumonia and may also develop renal failure. In kidney transplant (KT) patients, management of these patients was mainly based on anecdotal experience. CASE REPORT: We report our first experience of KT patients with COVID-19. A 49-year-old male with KT in 2017 presented on March 20, 2020, with fever, weakness, smell loss, chest pain, and caught. On chest X-ray, he presented ground-glass opacities and bilateral pneumonia. There was a slight progression to acute hypoxic respiratory failure. We reduced immunosuppression therapy and since we suspected seasonal flu, we applied available antiviral oseltamivir till confirmation of RNA sequence of the SARS-CoV-2 virus. Moreover, we applied azithromycin and broad spectrum of antibiotics as well as an anticoagulant therapy. Graft function remained stable during 14 days of hospitalization. The patient clinically improved with decreasing oxygen requirements and manifested clinical recovery. After two negative PCR test, he was discharged and immunosuppression therapy was returned to previous. CONCLUSION: This case highlights the importance of earlier outpatient hospitalization and testing which may improve COVID-19 outcomes among transplanted patients

The Ilioinguinal Approach versus the Anterior Intrapelvic Approach to the Acetabulum: A Review

The ilioinguinal approach (IIA) to the acetabulum has been used as a golden standard for fifty years to treat “anterior†acetabular fractures. Since its introduction by Hirvensalo and Cole, the anterior intrapelvic approach (AIPA) has been adopted by some surgeons, whilst others remain devoted to the IIA. IIA is routinely used in the Republic of Macedonia. The aim of this study is to present a review of literature for two different anterior approaches for the treatment of acetabular fractures used in modern day surgery, focussing on AIPA and its priorities and comparing it to IIA.We performed a search, mainly electronically, and retrospective analysis of existing literature. We have identified and selected two representative and well-systematized papers for IIA, and six for AIPA. We presented the advantages and disadvantages, priorities and weaknesses of both approaches separately, comparing complications, risks and results. Based on the facts presented regarding the advantages of AIPA with a focus on visualization, accessibility and biomechanical justification, the approach should be implemented in our everyday practice and we are comfortable in stating this preference, especially due to the fact that upon comparison of the complication rate there is no significant difference between the two approaches

Effect of oral calcium carbonate on aortic calcification in apolipoprotein E-deficient (apoE−/−) mice with chronic renal failure

Background. In chronic kidney disease (CKD) patients, the intake of calcium-based phosphate binders is associated with a marked progression of coronary artery and aortic calcification, in contrast to patients receiving calcium-free phosphate binders. The aim of this study was to reexamine the role of calcium carbonate in vascular calcification and to analyse its effect on aortic calcification-related gene expression in chronic renal failure (CRF). Methods. Mice deficient in apolipoprotein E underwent either sham operation or subtotal nephrectomy to create CRF. They were then randomly assigned to one of the three following groups: a control non-CRF group and a CRF group fed on standard diet, and a CRF group fed on calcium carbonate enriched diet, for a period of 8 weeks. Aortic atherosclerotic plaque and calcification were evaluated using quantitative morphologic image processing. Aortic gene and protein expression was examined using immunohistochemistry and Q-PCR methods. Results. Calcium carbonate supplementation was effective in decreasing serum phosphorus but was associated with a higher serum calcium concentration. Compared with standard diet, calcium carbonate enriched diet unexpectedly induced a significant decrease of both plaque (p < 0.05) and non-plaque-associated calcification surface (p < 0.05) in CRF mice. It also increased osteopontin (OPN) protein expression in atherosclerotic lesion areas of aortic root. There was also a numerical increase in OPN and osteoprotegerin gene expression in total thoracic aorta but the difference did not reach the level of significance. Finally, calcium carbonate did not change the severity of atherosclerotic lesions. Conclusion. In this experimental model of CRF, calcium carbonate supplementation did not accelerate but instead decreased vascular calcification. If our observation can be extrapolated to humans, it appears to question the contention that calcium carbonate supplementation, at least when given in moderate amounts, necessarily enhances vascular calcification. It is also compatible with the hypothesis of a preponderant role of phosphorus over that of calcium in promoting vascular calcification in CR

Two Stage Minimally Invasive Method with Locking Plate Application on Distal Tibia Fractures - Our Experience

INTRODUCTION: In the past distal tibia fractures, including intraarticular fractures, frequently led to poor functional outcomes. The Ruedi-Allgower four steps open method, and later the Patterson and Sirkin recommendations for delayed operative treatment has made a drastic advancement in the treatment of these fractures. The two-stage minimally-invasive protocol using locking plate fixation proved a historical turning point, improving functional results to the highest levels compared to all other methods.AIM: To present the superior results of the two-stage minimally-invasive method using locking plate fixation, making this a historic step forward in treating distal tibia fractures.MATERIAL AND METHODS: A prospective longitudinal study, collecting data from Traumatology-Clinic in the 2014-2016 periods, available for nine-month follow-up. Twenty-three patients were finally included in the study.RESULTS: In analysing the data collected, we focused our attention on the final functional outcomes as indicated by dorsiflexion nine months after injury and also according to the AOFAS Ankle-Hindfoot Scale. Results were excellent with no or minimal consequences. Where complications were present, these were benign and did not require further surgery.CONCLUSION: We believe this modern method for the treatment of distal tibia fractures should be applied routinely and considered as the gold standard in this domain

Complications and Risks of Percutaneous Renal Biopsy

BACKGROUND: Renal biopsy performed in native and transplant kidneys is generally considered a safe procedure. AIM: In this study, we evaluated renal biopsy complications and risk factors in one nephrology facility. MATERIAL AND METHODS: We conducted a three-year retrospective study on patients who underwent renal biopsy between January 2014 and December 2016. Strict written biopsy protocol was followed. Clinical and laboratory data were obtained from medical charts. Complications were categorised as minor and major, according to the need for intervention. Minor complications included macrohematuria and/or hematoma that did not require intervention. Major complications included hematuria or hematoma with fall of hematocrit that required a blood transfusion, surgery or caused death. A binary logistic regression model was used to analyse the possible factors associated with complications after the biopsy. RESULTS: We analysed 345 biopsies; samples were taken from patients aged from 15-81 years, of whom 61% were men. A total of 21 (6%) patients developed a complication, 4.4% minor and 1.7% major complications. There were no nephrectomy or death due to biopsy intervention. Overweight patients, as well as those with higher creatinine, lower hemoglobin, higher blood pressure and biopsy due to AKI had higher chances to develop complications (p = 0.037, p = 0.023, p = 0.032, p = 0.002, p = 0.002, respectively). The patients’ age, gender, kidney dimension, number of passes and uninterrupted aspirin therapy were not found as significant predictors of complications. In the multivariate logistic model, body weight (OR = 1.031, 95%CI = 1.002-1.062), lower hemoglobin (OR = 0.973, 95%CI = 0.951–0.996) and hypertension (OR = 1.025, 95%CI = 1.007-1.044) increased the risk of complications in biopsied patients. CONCLUSION: Renal biopsy is a safe procedure with a low risk of complications when strict biopsy protocol is observed. Correction of anaemia and blood pressure is to be considered before the biopsy

On harmonization of radon maps

Background: Maps are important tools for geographic visualization of the state of the environment with respect to resources as well as to hazards. One of the hazards is indoor radon (Rn), believed to be the most important cause of lung cancer after smoking. In particular, as part of Rn mitigation policy and in compliance with the European Basic Safety Standards, EU Member States have to declare areas with elevated indoor Rn concentration levels. However, as this is done by national authorities according to individually chosen criteria, the resulting maps are not easily comparable.Objective: We aim to identify causes for the lack of compatibility of maps and suggest solutions for the problem.Design: This study draws from experiences of recent research projects, literature, and personal involvement of the authors in the discussions.Results: An overview is given on causes and effects of lack of compatibility between maps. Existing experiences are reported. Options for defining lack of compatibility and for identifying it are discussed. Methods for harmonization, that is, remediating lack of compatibility, are addressed.Conclusions: The difficulty of harmonization increases with the aggregation level of data which support maps. Harmonization is the more difficult, the higher aggregated the data are which support maps. In particular, harmonization of radon priority area maps is technically non-trivial, and theoretical efforts as well as practical tests will have to be undertaken.Special issue - European Radon Week 202