Vascular access failure-cause or complication of central venous catheterization: Case report

© 2020, University of Kragujevac, Faculty of Science. All rights reserved. The quality of life and patient survival rate in terminal chronic renal insufficiency depends on the duration of vascular approaches. Dialysis catheters are used to establish an adequate vascular approach when emergency hemodialysis is indicated and when all approaches are exhausted. Complications of CVC can be classified into three categories: mechanical (hematoma, arterial puncture, pneumothorax, hemothorax, catheter misplacement, and stenosis), infectious (insertion site infection, CVC colonization, and bloodstream infection) and thrombotic (deep vein thrombosis). Despite the increasing prevalence of haemodialysis patients with complex access issues, there remains no consensus on the definition of vascular access failure or end-stage vascular access. The dilema in these cases remains whether the generalized vascular insufficiency is the cause or a complication of exhausted vascular accesses. This case report is one of the examples of combined complications with generalized vascular access insufficiency. During the year and a half of the chronic dialysis program, the patient had several changes of vascular approaches, and each approach became dysfunctional in certain time due to various causes. After six months of successful hemodialysis, the patient was admitted with signs of infection and during hospitalization was again subjected to multiple changes of the vascular approach due to infection, thrombosis, and vascular access failure

Evaluation of different formulas for LDL-C calculation

<p>Abstract</p> <p>Background</p> <p>Friedewald's formula for the estimation of LDL-C concentration is the most often used formula in clinical practice. A recent formula by Anandaraja and colleagues for LDL-C estimation still needs to be evaluated before it is extensively applied in diagnosis. In the present study we validated existing formulas and derived a more accurate formula to determine LDL-C in a Serbian population.</p> <p>Methods</p> <p>Our study included 2053 patients with TG ≤ 4.52 mmol/L. In an initial group of 1010 patients, Friedewald's and Anandaraja's formulas were compared to a direct homogenous method for LDL-C determination. The obtained results allowed us to modify Friedewald's formula and apply it in a second group of patients.</p> <p>Results</p> <p>The mean LDL-C concentrations were 3.9 ± 1.09 mmol/L, 3.63 ± 1.06 mmol/L and 3.72 ± 1.04 mmol/L measured by a direct homogenous assay (D-LDL-C), calculated by Friedewald's formula (F-LDL-C) and calculated by Anandaraja's formula (A-LDL-C), respectively in the 1010 patients. The Student's paired t-test showed that D-LDL-C values were significantly higher than F-LDL-C and A-LDL-C values (p < 0.001). The Passing-Bablok regression analysis indicated good correlation between calculated and measured LDL-Cs (r > 0.89). Using lipoprotein values from the initial group we modified Friedewald's formula by replacing the term 2.2 with 3. The new modified formula for LDL-C estimation (S-LDL-C) showed no statistically significant difference compared to D-LDL-C. The absolute bias between these two methods was -0.06 ± 0.37 mmol/L with a high correlation coefficient (r = 0.96).</p> <p>Conclusions</p> <p>Our modified formula for LDL-C estimation appears to be more accurate than both Friedewald's and Anandaraja's formulas when applied to a Serbian population.</p

Internal Illumination to Overcome the Cell Density Limitation in the Scale-up of Whole-Cell Photobiocatalysis

Cyanobacteria have the capacity to use photosynthesis to fuel their metabolism, which makes them highly promising production systems for the sustainable production of chemicals. Yet, their dependency on visible light limits the cell‐density, which is a challenge for the scale‐up. Here, it was shown with the example of a light‐dependent biotransformation that internal illumination in a bubble column reactor equipped with wireless light emitters (WLEs) could overcome this limitation. Cells of the cyanobacterium Synechocystis sp. PCC 6803 expressing the gene of the ene‐reductase YqjM were used for the reduction of 2‐methylmaleimide to (R)‐2‐methylsuccinimide with high optical purity (>99 % ee). Compared to external source of light, illumination by floating wireless light emitters allowed a more than two‐fold rate increase. Under optimized conditions, product formation rates up to 3.7 mm h(−1) and specific activities of up to 65.5 U g(DCW) (−1) were obtained, allowing the reduction of 40 mm 2‐methylmaleimide with 650 mg isolated enantiopure product (73 % yield). The results demonstrate the principle of internal illumination as a means to overcome the intrinsic cell density limitation of cyanobacterial biotransformations, obtaining high reaction rates in a scalable photobioreactor

The importance of copper in pathology of mesial temporal lobe epilepsy

More and more studies are identifying the regulation of metal homeostasis as one of the key points of central nervous system’s well-being. Epilepsy is a particularly interesting neurological condition when viewed in terms of the correlation between the amount of metals and the development of a seizure. This lecture will present contribution of our group to the field of metal biology in epilepsy by mapping brain metals in sclerotic hippocampus resected from drug resistant mesial temporal lobe epilepsy (mTLE) patients as surgical therapeutic approach. Direct insight into this epileptogenic area, by two powerful techniques, optical emission and mass spectrometry, has led us to investigation of copper turnover. Namely, among the examined metals, we found the deficiency of copper in sclerotic hippocampus on two levels: (i) in whole structure (ii) and locally in the areas of neuronal loss, with significant correlation between copper concentration and neuron density. Furthermore, analysis of copper metalloproteins showed: (i) significant increase or decrease in levels of protein that is participating in copper transport into the cell (CTR1) depending on the degree of hippocampal neuronal loss; (ii) and lower activity of an enzyme in which copper is part of the active site, cytochrome c oxidase, in sclerotic hippocampi of patients compared to control tissue. In our further investigations it remained to be determined whether changes in copper concentrations and copper metalloproteins are causal to pathology of mTLE or they represent epiphenomenon

Extraintestinal manifestations of the eye in patients with inflammatory bowel diseases

© 2017, Serbian Medical Society. All rights reserved. Extraintestinal manifestations of Crohn’s disease and ulcerative colitis were observed in almost half of the patients. They should be distinguished from secondary illnesses and complications. The most commonly affected organs are joints, skin, eyes, liver, gallbladder, urogenital and hematopoietic system. Eye manifestations are, although rare, an important form of morbidity, with possible blindness. The prevalence is higher in women and if the bowel disease is diagnosed at younger age, but lower than in children. Considering the great impact on the life quality, sometimes higher than gastrointestinal symptoms are, the goal is to show the importance of recognition and clinical and diagnostic approach to some ophthalmic entities. Symptomology of the most common changes, iritis, episcleritis and scleritis is nonspecific, and therefore the clinical evaluation is potentially underestimated both from the patient’s and from the doctor’s point of view. Ophthalmologic examination should be more frequent and an integral part of care for patients with inflammatory bowel disease. It is necessary to be well aware of the possible symptoms on the eye diseases, because they can precede inflammatory bowel disease. Treatment and adequate control of basic systemic disease contribute to the control of eye disease

An Approach to Reliability Assessment of Complex Systems at CERN

This paper presents the systematic approach Reliability Requirements and Initial Risk Evaluation (RIRE) developed and used at CERN. RIRE is a four-step procedure, which provides a framework for the experience based derivation of quantitative reliability targets for CERN’s accelerator systems. These targets are not subject to statutory regulations. RIRE shows the risks posed by a system and prioritizes subsequent, more detailed analyses, such as Fault Tree. The application of RIRE to the quench detection system of the LHC super conducting magnets is shown in this paper. From this example is concluded that RIRE is suitable for the analysis of a complex system with context dependent functions.This paper presents the systematic approach Reliability Requirements and Initial Risk Evaluation (RIRE) developed and used at CERN. RIRE is a four-step procedure, which provides a framework for the experience based derivation of quantitative reliability targets for CERN’s accelerator systems. These targets are not subject to statutory regulations. RIRE shows the risks posed by a system and prioritizes subsequent, more detailed analyses, such as Fault Tree. The application of RIRE to the quench detection system of the LHC super conducting magnets is shown in this paper. From this example it is concluded that RIRE is suitable for the analysis of a complex system with context dependent functions

An Approach to Reliability Assessment of Complex Systems at CERN

This paper presents the systematic approach Reliability Requirements and Initial Risk Evaluation (RIRE) developed and used at CERN. RIRE is a four-step procedure, which provides a framework for the experience based derivation of quantitative reliability targets for CERN’s accelerator systems. These targets are not subject to statutory regulations. RIRE shows the risks posed by a system and prioritizes subsequent, more detailed analyses, such as Fault Tree. The application of RIRE to the quench detection system of the LHC super conducting magnets is shown in this paper. From this example is concluded that RIRE is suitable for the analysis of a complex system with context dependent functions.This paper presents the systematic approach Reliability Requirements and Initial Risk Evaluation (RIRE) developed and used at CERN. RIRE is a four-step procedure, which provides a framework for the experience based derivation of quantitative reliability targets for CERN’s accelerator systems. These targets are not subject to statutory regulations. RIRE shows the risks posed by a system and prioritizes subsequent, more detailed analyses, such as Fault Tree. The application of RIRE to the quench detection system of the LHC super conducting magnets is shown in this paper. From this example it is concluded that RIRE is suitable for the analysis of a complex system with context dependent functions

New Quench Detection System to Enhance Protection of the Individually Powered Magnets in the Large Hadron Collider

To further improve the existing Quench Detection System (QDS) of individually powered magnets installed in the Large Hadron Collider (LHC), a new radiation tolerant electronic board was developed. The board provides three signal acquisition channels. It is able to acquire with different and configurable signal resolution and acquisition rate the analog signals of different properties. These enhancements enable the application of different quench detection algorithms depending on the protected magnet. Additionally, the board can be used with newly developed current derivative sensors for reliable detection of symmetric quenches. The new system supports both open and closed loop current sensors

The reaction of methionine with hydroxyl radical: reactive intermediates and methanethiol production

The mechanisms of reaction of methionine with hydroxyl radical are not fully understood. Here, we unequivocally show using electron paramagnetic resonance spin-trapping spectroscopy and GC-FID and GC-MS, the presence of specific carbon-, nitrogen- and sulfur-centered radicals as intermediates of this reaction, as well as the liberation of methanethiol as a gaseous end product. Taking into account the many roles that methionine has in eco- and biosystems, our results may elucidate redox chemistry of this amino acid and processes that methionine is involved in