Resolution of high-output cardiac failure secondary to high flow radiocephalic fistula by precision banding under ultrasound guidance: A case report

Background: The creation of dialysis shunt affects hemodynamic and cardiac function. High-output cardiac failure may occur if dialysis access volume flow is greater than 1500 to 2000 mls/min. To resolve symptoms of cardiac failure due to high flow dialysis shunt requires flow reduction procedure. We describe successful resolution of symptoms of heart failure due to excessive flow dialysis access by adopting precision banding, totally under vascular ultrasound guidance without angiography. Case: Hemodialysis adult patient uses the right arm radiocephalic fistula for 4 years. Recently, the patient presented with symptoms of high-output cardiac failure, including dyspnea, palpitations, fatigue, and orthopnea. The cardiac unit excluded all other causes of cardiac failure and referred the patient to our center for further evaluation. Ultrasonography revealed high blood volume flow measuring 3100 mls/min at brachial artery, marking high flow fistula and the underlying cause of cardiac failure. Juxta-anastomotic segment of fistula vein was identified; 3 mm diameter balloon was advanced to the juxta-anastomotic segment and maximally inflated. Two precision bandings were made on this segment, 1 to 2 cm apart with flow reduction to 691 mls/min. All steps of the procedure were done under ultrasound guidance without angiography. All symptoms were significantly alleviated immediately following the procedure. The patient was discharged after 48 h of monitoring. At 6 months, the patient was stable, no recurrence of high flow access, no signs or symptoms of cardiac failure, and the flow was 1119 mls/min. Conclusion: This case demonstrates that the precision banding procedure is feasible under ultrasound guidance, and the procedure is safe and effective in resolution of cardiac failure due to high flow radiocephalic fistula.

Comparative methodological studies of L-asparaginase encapsulation into erythrocytes

Background. L-asparaginase is an enzyme, widely used in the therapy of acute lymphoblastic leukemia in children and adults, but its use is limited due to a wide range of side effects and anaphylactic reactions. L-asparaginase loaded into erythrocytes can solve these problems. This enzyme is protected from the immune system and plasma proteases due to erythrocyte membrane, but continues to work inside the cell because its membrane is permeable to L-asparagine. Thus, the half-life of the drug increases and anaphylactic reactions reduce. The encapsulation of L-asparaginase into erythrocytes can be performed by various osmotic methods. Each of them is characterized by the amount of encapsulated enzyme, the cell yield, as well as by the quality indices of the survived erythrocytes. An important parameter of each method is the possibility to provide sterility of this dosage form for the clinical use.The aim of the study was the comparing of three osmotic methods of L-asparaginase encapsulation into erythrocytes (hypo-osmotic lysis, dialysis and flow dialysis) to select the most promising method for clinical use.Materials and methods. A suspension of erythrocytes of healthy donors (hematocrit 60–70%) was mixed with L-asparaginase from E. сoli. The procedures of hypotonic reversible lysis, dialysis in dialysis bags, or flow dialysis using pediatric dialyzers were performed. The physiological osmolality was restored in suspensions after the procedure by the addition of a hypertonic solution, and they were incubated for 30 min at 37 °C. Then the cells were washed in isotonic phosphate-buffered saline with pH 7.4. Activity of L-asparaginase, volume, hematocrit, hematological indices and osmotic cell fragility of erythrocytes were measured in the suspensions of erythrocytes before and after the enzyme encapsulation procedure.Results. An optimal osmolality of the hypotonic buffer for each method was selected and was equal to 90–110 mOsm/kg. The yields of encapsulation were 4.2 ± 2.0, 6.0 ± 2.3 and 16.2 ± 2.2 % for hypotonic lysis, dialysis and flow dialysis, respectively. The hematological indices of the obtained erythrocyte-carriers differed from the corresponding parameters of the initial erythrocytes, but did not differ significantly for different methods.Conclusion. Comparative investigation of mentioned above parameters allowed choosing the method of flow dialysis as the most promising for clinical use.

Bioaccessibility of ochratoxin A from red wine in an in vitro dynamic gastrointestinal model

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium species with immunosuppressive, teratogenic, and carcinogenic properties. It has been determined that wine is the second largest source of OTA (10% of total OTA intake) in the European diet and that its presence, even in small doses, can be a problem in terms of long-term toxicity. In this paper, we evaluated the bioaccessibility of OTA in a spiked red wine sample under human fasting conditions using an in vitro dynamic digestion model that includes a continuous-flow dialysis system to simulate intestinal passage. To the best of our knowledge, this report is the first examining the bioaccessibility of OTA in wine. A liquid-liquid method was used to extract the OTA and ochratoxin alpha (OTα) from gastrointestinal juices, and the extracts were analysed by HPLC with a fluorescence detector. The bioaccessibility of OTA from the spiked red wine (1.0, 2.0 and 4 μg/l) was high in the gastric compartment (102.8, 128.3 and 122.3%, respectively), whereas in the simulated intestine, it did not exceed 26%, and the amount of OTA that crossed the dialysis membrane was very low (<3.3%). The amount of OTα in gastric chyme ranged from 5.1 to 19.1% of the spiked OTA, whereas in the intestinal compartment it did not exceed 5%. In conclusion, in the in vitro system assayed, OTA exhibited a high bioaccessibility in the simulated stomach, but it decreased after the intestinal digestion and passage through the dialysis membrane.

Fortilin binds Ca2+ and blocks Ca2+-dependent apoptosis in vivo

Fortilin, a 172-amino-acid polypeptide present both in the cytosol and nucleus, possesses potent anti-apoptotic activity. Although fortilin is known to bind Ca2+, the biochemistry and biological significance of such an interaction remains unknown. In the present study we report that fortilin must bind Ca2+ in order to protect cells against Ca2+-dependent apoptosis. Using a standard Ca2+-overlay assay, we first validated that full-length fortilin binds Ca2+ and showed that the N-terminus (amino acids 1–72) is required for its Ca2+-binding. We then used flow dialysis and CD spectropolarimetry assays to demonstrate that fortilin binds Ca2+ with a dissociation constant (Kd) of approx. 10 μM and that the binding of fortilin to Ca2+ induces a significant change in the secondary structure of fortilin. In order to evaluate the impact of the binding of fortilin to Ca2+in vivo, we measured intracellular Ca2+ levels upon thapsigargin challenge and found that the lack of fortilin in the cell results in the exaggerated elevation of intracellular Ca2+ in the cell. We then tested various point mutants of fortilin for their Ca2+ binding and identified fortilin(E58A/E60A) to be a double-point mutant of fortilin lacking the ability of Ca2+-binding. We then found that wild-type fortilin, but not fortilin(E58A/E60A), protected cells against thapsigargin-induced apoptosis, suggesting that the binding of fortilin to Ca2+ is required for fortilin to protect cells against Ca2+-dependent apoptosis. Together, these results suggest that fortilin is an intracellular Ca2+ scavenger, protecting cells against Ca2+-dependent apoptosis by binding and sequestering Ca2+ from the downstream Ca2+-dependent apoptotic pathways.