Erythrocyte Suspensions Research Articles

Total Hip Arthroplasty in Patients with Idiopathic Thrombocytopenic Purpura

Background. There are no national clinical guidelines for the perioperative management of patients with idiopathic thrombocytopenia in hip arthroplasty. Most of the publications are presented in the context of general surgery, the distinguishing feature of which is the good achievement of hemostasis. However, it is impossible to achieve such a level of hemostasis with hip arthroplasty.
 The aim of the study was to evaluate the mid-term results of total hip arthroplasty in patients with primary idiopathic thrombocytopenia.
 Methods. Randomized monocenter clinical trial of 38 patients with idiopathic thrombocytopenia hip arthroplasty was performed. These patients was include in group I. As a control group, the outcomes of surgical treatment of 40 patients without thrombocytopenia over the same observation period were analyzed (group II). The mean follow-up period was 4.3 years. Exclusion criteria for the study were heparin-induced thrombocytopenia, a severe form of idiopathic thrombocytopenia in the acute stage with platelet counts less than 25109/L.
 Results. The average length of hospitalization was longer in patients with idiopathic thrombocytopenia (11.1 days). The results indicate a longer preoperative preparation, including the transfusion of hemocomponents with repeated monitoring of the parameters of the clinical blood test and coagulogram. There was no significant difference in the duration of the surgical intervention, but there were differences in the amount of intraoperative blood loss and the volume of blood transfusion. Among the patients of the group II, only 3 patients required intraoperative transfusion of one dose of erythrocyte suspension, patients of the group I more often underwent blood transfusion. In the group I, complications were noted in 5 patients, in the group II in one patient (p = 0.067), but the relative risk of complications was 5.2. Functional results 12 months after surgery didnt differ.
 Conclusions. The mid-term results of hip arthroplasty in patients with idiopathic thrombocytopenia are comparable to the results in patients of the general population. A distinctive feature of surgical intervention is an increase in the average volume of intraoperative blood loss and the need for a significantly larger transfusion of hemocomponents not only during the operation, but also in the preoperative period, which increases the duration of hospitalization.

Changes in indicators of the prooxidant-antioxidant system in patients with drug addiction during the rehabilitation

Background: Despite the positive dynamics in this scientific area, the prevalence of drug pathology in Russia and other countries of the world remains unfavorable. Determination of laboratory markers of pathobiochemical processes which are characteristic to the patients with substance use disorder is promising from the standpoint of monitoring the course of the disease and evaluating the effectiveness of therapy.Objective: To determine the characteristic changes in oxidative homeostasis of patients with addiction to psychostimulants and opioids at the rehabilitation and anti‑relapse stage.Material and methods: The study was performed with the participation of 20 relatively healthy male volunteers and 18 male patients with addiction to opioids or psychostimulants who then became participants of the rehabilitation and anti‑relapse course of treatment. Changes in oxidative stress markers during rehabilitation and anti‑relapse treatment were studied.Results: In comparison to the control values at the initial stage of the study, patients of the main group demonstrated decreased values of the iron‑reducing ability of blood plasma – by 25%, as well as those of the sorption radical ability of blood plasma – by 30%; the content of thiol groups of blood plasma proteins decreased by 24% while the concentration of glutathione in erythrocyte suspension lowered by 26%. The level of TBA‑reactive products in erythrocyte suspension corresponded to the control level. The performed rehabilitation manipulations contributed to the partial normalization of oxidative homeostasis, which was confirmed by a statistically significant increase in the ability of radical sorption of blood plasma by 20% and the concentration of reduced glutathione in erythrocyte suspension by 28% in comparison to the initial values of the corresponding parameters in patients of the 2nd group. The TBA‑reactive products remained within the control values.Conclusion: The studied markers are suitable for monitoring the state of oxidative homeostasis in patients with opioid or psychostimulant addiction, the imbalance of which at the end of the rehabilitation and anti‑relapse stage also indicates the prospects for strengthening the antioxidant component as part of drug or nutritional correction.

Evaluation of disorders of adaptive mechanisms in heart failure by microwave dielectrometry

Differential diagnosis of stress adaptive mechanisms is one of the areas of modern biomedical engineering and the most complex part of the pre-nosological diagnosis of cardiac pathology. One of the manifestations of disadaptation in heart failure is a violation of the mechanisms of realization of the intracellular chain "signal-function". The concept of imbalance in the functioning of the adenylate cyclase system and β-adrenergic receptors of the erythrocytes membrane and cardiomyocytes is considered in the pathogenesis of the heart.
 The study of the dielectric constant (ε՜) of erythrocytes of patients with heart failure was performed using an instrument-recording complex based on microwave dielectrometry of the γ-dispersion region of free water dielectric permittivity. Testing of the β-adrenergic complex of the erythrocyte membrane by specific stimulators, blockers, and modulators was implemented at a fixed frequency of microwave radiofrequency generation (f = 37,7 GHz). Interpretation of the obtained experimental data was that the process of interaction of bioregulators with the biological system is accompanied by an increase or decrease in the relative amount of free water, which leads to a change in the real part of ε՜ complex dielectric constant. This allowed us to visualize the violation of the signal cell system at the molecular level, which manifested itself in the change of integral hydration by ε՜ parameter. It was shown that the change in the dielectric constant of the erythrocyte suspension at risk (patients with hereditary predisposition to dilated and ischemic cardiomyopathy) was significant relative to the dielectric parameters of erythrocyte samples from healthy donors; there was a tendency to block β-adrenergic receptors, with the combined action of adrenaline, PGE2 and cordanum, with Δε՜ = 0,009 ± 0,008 х 10-12 F/m. It should be noted the formation of preconditions for changes in the functioning of the adenylate cyclase system and the development of heart failure in the group at risk, is accompanied by dilated and ischemic cardiomyopathy.
 The effectiveness of the microwave dielectrometry method for the assessment of violations of adaptation mechanisms through the adenylate cyclase system of the erythrocyte membrane in dilated and ischemic forms of cardiomyopathies is shown. The results of the study are the basis for the introduction of the dielectric constant criterion in the general algorithm of pre-nosological diagnosis of heart failure.

The effect of G-CSF used after allogeneic hematopoietic stem cell transplantation on engraftment times and platelet suspension replacement numbers

BackgroundWith the use of granulocyte colony stimulating factor (G-CSF) after allogeneic hematopoietic stem cell transplantation (HSCT), the duration of neutrophil engraftment and hospitalization were shortened. However, there is no consensus on the effect of G-CSF on platelet engraftment time. The primary aim of our study is to determine the effect of G-CSF use on platelet engraftment time after HSCT. Secondary purposes are to determine the number of platelet suspension, number of erythrocyte suspension and incidence of acute graft versus disease after HSCT. Material and methodsPatients who had allogeneic stem cell transplantation at our center between 01.01.2011 and 01.01.2022 were retrospectively analyzed. Patients were divided into 2 groups as those who received and did not receive G-CSF after transplantation. ResultsA total of 64 patients were included. While 32 patients were given post-HSCT G-CSF support, the other 32 patients were not given. Neutrophil engraftment time and length of hospital stay were shorter in the group receiving G-CSF (p < 0.05). Platelet engraftment time was shorter in the group that did not receive G-CSF (p < 0.05). The incidence of acute GVHD of the patients in group 1 tended to be higher than the patients in group 2 (40.6 % vs 15.6 %, p = 0.052). Post-HSCT platelet suspension was less in the group that did not receive G-CSF, but this difference was not statistically significant (p = 0.173). ConclusionWhile the positive effect of post HSCT G-CSF use on duration of neutrophil engraftment and hospitalization is evident, its effects on platelet engraftment need to be investigated.

Comparison of urgent and early endoscopy for acute non-variceal upper gastrointestinal bleeding in high-risk patients

ObjectiveData regarding early (within 24h) and urgent endoscopy (within 12h) in non-variceal upper gastrointestinal bleeding (NV-UGIB) revealed conflicting results. This study aimed to investigate the impact of endoscopy timing on the outcomes of high-risk patients with NV-UGIB. Patients and methodsFrom February 2020 to February 2021, consecutive high-risk (Glasgow–Blatchford score ≥12) adults admitted to the emergency department with NV-UGIB were analyzed retrospectively. The primary composite outcome was 30-day mortality from any cause, inpatient rebleeding, need for endoscopic re-intervention, need for surgery or angiographic embolization. Results240 patients were enrolled: 152 (63%) patients underwent urgent endoscopy (<12h) and 88 (37%) patients underwent early endoscopy (12–24h). One or more components of the composite outcome were observed in 53 (22.1%) patients: 30 (12.5%) had 30-day mortality, rebleeding occurred in 27 (11.3%), 7 (2.9%) underwent endoscopic re-intervention, and 5 (2.1%) required surgery or angiographic embolization. The composite outcome was similar between the groups. Multivariate analysis showed only hemodynamic instability on admission (OR: 3.05, p=0.006), and the previous history of cancer (OR: 2.42, p=0.029) were significant in predicting composite outcome. In terms of secondary outcomes, the endoscopic intervention was higher in the urgent endoscopy group (p=0.006), whereas the number of transfused erythrocyte suspensions and the length of hospital stay was higher in the early endoscopy group (p=0.002 and p=0.040, respectively). ConclusionsUrgent endoscopy leads to a significant reduction in the length of hospitalization and the number of transfused erythrocyte suspensions in NV-UGIB, which can contribute to patient satisfaction, reduce healthcare expenditure, and improve hospital bed availability. The composite outcome and its sub-outcomes were the same among both groups.

Investigation of the clinical efficacy and safety of herbal Algan Hemostatic Agent in coronary artery bypass graft surgery

Background. Hemostatic agents have the potential to improve clinical outcomes by decreasing postoperative drainage and the need for transfusions. Algan Hemostatic Agent is a polysaccharide-based hemostatic agent obtained from a mixture of six different herbs. The aim of this study is to investigate the clinical efficacy and safety of Algan Hemostatic Agent as a local hemostatic agent in coronary artery bypass operations. Methods. 28 subjects who underwent isolated coronary artery bypass graft surgery and met the inclusion criteria were included in this clinical study. Traditional methods (cautery, ligation, etc.) were used in the control group, whereas Algan Hemostatic Agent was added in the study group. A sponge soaked in Algan Hemostatic Agent liquid was lightly compressed to the bleeding area for 120 seconds. Results. Both groups were comparable in terms of preoperative demographic data and perioperative laboratory values. Drainage on the postoperative first day (650 ml vs 896 ml; p=0.381) and total drainage (817 ml vs 1210 ml; p=0.031) were found higher in the control group. Another significant difference was observed between the groups in terms of erythrocyte suspension utilization rate (1.14 U in the treatment group and 2.06 U in the control group, p=0.004). Algan Hemostatic Agent did not cause any complications during administration. Conclusion. In conclusion, Algan Hemostatic Agent has been found effective and safe in controlling bleeding during coronary artery bypass operations.

STUDY OF ASPIRIN EFFECT ON STABILITY OF MEMBRANES OF RAT BLOOD ERYTHROCYTES BY ACIDIC HEMOLYSIS METHOD

In this work the effect of aspirin on stability of rat blood erythrocyte membranes was studied, using acidic hemolysis method. Hemolysis rate of erythrocytes was shown to depend on preservation time of rat erythrocyte suspension. With increasing of preservation time the original value of optic density of rat erythrocyte suspension decreases and hemolysis time reduces. It was also shown that in the presence of aspirin the membrane stability of low-stable erythrocytes increases, moreover, hemolysis duration enhances, while aspirin leads to decreasing of membrane stability of both high-stable and enhanced-stable erythrocytes of rats.

Effects of biomechanical properties of blood on surface tension-driven flows in superhydrophilic channels

Surface tension-driven microfluidic flows offer low-cost solutions for blood diagnostics due to the pump-less flow handling. Knowledge of the influence of the biomechanical properties of blood on such flows is key to design such devices; however, a systematic examination of that influence is lacking in the literature. We report on the effects of specific hemorheological factors for flows in a superhydrophilic microchannel. Whole human blood and erythrocyte suspensions in phosphate buffer and dextran solutions were tested. Heat-treated counterparts of the aforementioned samples were produced to alter the deformability of the cells. The flow of the samples was imaged and characterized using micro-particle image velocimetry and tracking techniques to probe the effects of hematocrit, and erythrocyte aggregation and deformability. Meniscus velocities, velocity profiles in the channel, and local and bulk shear rates were derived. The mean velocity of blood was affected by the increasing sample viscosity and the reduced erythrocyte deformability as expected. The increased erythrocyte aggregation appeared to affect more the shape of the velocity profiles in the normal, compared to the heat-treated samples. Very high shear rates are observed in the early stages of the flow, suggesting high erythrocyte disaggregation, persisting sufficiently strong until the flow reaches the end of the channel.

Comparison of Splenectomy Indications According to Clinicopathological Variables

Background: The aim of this study is to evaluate the preoperative, intraoperative and postoperative differences in patients who underwent splenectomy for benign and malignant diseases.&#x0D; Materials and Methods: Adult patients (18 years and older) who underwent splenectomy in a tertiary health center between January 2015 and January 2021 were searched retrospectively. The patients were divided into two main indication groups: patients who underwent splenectomy for benign diseases (n=35) and patients who underwent splenectomy during malignancy surgery (n=45). In addition, benign indications were also divided into three subgroups. Clinicopathological variables obtained from the patients' medical records were compared between both main groups and subgroups.&#x0D; Results: The mean age of 80 patients who met the study criteria was 53.47±18.28 (18-86), and 44 patients (55%) were female. The mean age of the patients, laparoscopic surgery rate, elective surgery rate, postoperative complication rate, need for erythrocyte suspension and fresh frozen plasma, length of hospital stay and length of stay in the intensive care unit were higher in the malignancy group. In addition, splenectomy cases due to malignancy were proportionally higher in recent years. Another important result of the study was that traumatic splenectomies require longer hospitalization, and the management of these patients' clinics is more difficult than other benign splenectomy causes.&#x0D; Conclusion: Among all splenectomy cases, malignant splenectomy cases and benign splenectomy cases who underwent traumatic splenectomy are difficult to manage because of longer hospital stay, more need for blood products, and high morbidity rates.

Clinical features of methods for collecting hematopoietic stem cells in patients with malignant neoplasms weighing up to 15 kg and early age

Relevance. Autologous hematopoietic stem cell transplantation (auto-HSCT) is an integral part of the treatment of patients with high-risk malignancies. However, carrying out the mobilization and collection of hematopoietic stem cells (HSC) for patients weighing up to 15 kg is a complex task that requires a special approach and multidisciplinary interaction.The purpose of the study is to present the experience of collecting HSC in young children weighing up to 15 kg at the Research Institute of Pediatric Oncology and Hematology of the Federal State Budgetary Institution N.N. Blokhin National Medical Research Centre of Oncology, Ministry of Health of Russia.Materials and methods. The study included 30 patients weighing up to 15 kg who received treatment from January 2020 to May 2021 at the Research Institute of Pediatric Oncology and Hematology of the Federal State Budgetary Institution N.N. Blokhin National Medical Research Centre of Oncology, Ministry of Health of Russia. Median age was 30.6 (12–48) months, median body weight was 12.2 (7.8–15) kg. Apheresis in children weighing up to 15 kg was performed in the resuscitation and intensive care unit with the condition of pre-filling the cell separator circuit with a donor irradiated erythrocyte suspension to prevent hypovolemic complications. Thirty two apheresis was performed on a cell separator of the “Spectra Optia” type. To mobilize HSC, preparations of granulocyte colony-stimulating factor with the main active ingredient filgrastim were used.Results. Twenty eight HSC apheresis procedures were successful on the first attempt, 2 patients underwent repeated apheresis (a total of 32 procedures were performed). The median number of CD34+ cells obtained was 13.9 × 106/kg (0.04–92.0 × 106/kg), and the median apheresis duration was 251 (160–415) min. In 2 children during the procedure, an immediate organization of repeated venous access was required.Conclusions. Performing HSC apheresis in children weighing up to 15 kg and young children is a safe and effective technique with the participation of a multidisciplinary team. The apheresis algorithm proposed by us makes it possible to carry out a high-quality collection of CD34+ cells, sufficient for auto-HSCT.

A clinical study on the effects of dexmedetomidine and propofol on erythrocyte deformability during anaesthesia

Purpose: To investigate the clinical effects of dexmedetomidine and propofol on erythrocyte deformability (ED) in patients undergoing laparoscopic cholecystectomy.Methods: A total of 522 patients undergoing gallbladder removal surgery were randomly divided into groups A (dexmedetomidine group), B (propofol group), and C (control). Erythrocyte suspensions were prepared from each group. Then, erythrocyte deformability index (EI) was measured in terms of RBC deformability. Moreover, endothelial nitric oxide synthase (eNOS) activity, and concentrations of nitric oxide (NO) were determined. Patients in the three groups received the same anaesthesia induction and maintenance, and their EI and Hct values were assayed before anaesthesia (T0) and post-surgery (T1). The activity of eNOS in each group was assayed using immunofluorescence microscopy and western blotting analysis.Results: There were higher levels of EI and NO, and higher eNOS activity in erythrocytes in the dexmedetomidine group than in the propofol and ginsenoside groups (p &lt; 0.05). Post-naethesia EI (T0) values were higher in propofol and control groups than in dexmedetomidine group (p &lt; 0.05). The protein expression of eNOS was higher in dexmedetomidine group, as was evident from immunofluorescence and western blotting analyses.Conclusion: Perioperative use of dexmedetomidine during anaesthesia increases RBC deformability in vitro and directly upregulates eNOS activity in erythrocytes.

Factors Affecting ICU Stay and Length of Stay in the ICU in Patients with HELLP Syndrome in a Tertiary Referral Hospital

Objective The study aimed to compare patients with HELLP syndrome who require intensive care and who do not require intensive care and evaluate the factors affecting the length of stay in the intensive care unit. Methods Patients were divided into two groups as follows: requiring intensive care (group 1) and not requiring intensive care (group 2). The data of both groups were compared in terms of demographic characteristics, transfusion amounts, length of stay in the intensive care unit, maternal complications, and mortality. Results 14032 births in a tertiary center between 2011 and 2018 were evaluated in this study. During the study period, 342 patients were diagnosed with HELLP, and 32 (9.4%) of these were followed up in the intensive care unit. The length of stay in the intensive care unit was determined as 8.1 (7.2) days on average. Fresh frozen plasma, erythrocyte suspension, apheresis, and random thrombocyte transfusion were observed to be significantly more in group 1 patients. In the regression analysis, the most effective factor was found to be erythrocyte suspension and the length of stay in the intensive care unit was significantly longer in patients who had erythrocyte suspension transfusion. The receiver operating characteristic curve showed that the area under the curve value for erythrocyte transfusion was 70.6%. When the cutoff value of erythrocyte suspension was 450 (95% CI: 365–681) ml, the sensitivity was 43.8% and the specificity was 91.6%. Conclusion We think that physicians should be careful that maternal morbidity and mortality may increase as the need for erythrocyte suspension transfusion increases in patients with HELLP syndrome. Minimum transfusion to hemodynamically stable patients can be more suitable in terms of morbidity and mortality in managing patients with HELLP syndrome requiring erythrocyte suspension transfusion. Precautions and measures should be taken in this regard.

Splenectomy during Gastric Cancer Surgery versus Splenectomy during Extra-gastric Abdominal Cancer Surgery.

To evaluate the clinicopathological differences between splenectomy during gastric cancer surgery and splenectomy during extra-gastric abdominal cancer surgery. Observational study. Erzurum Regional Education and Research Hospital, Erzurum, Turkey between January 2015 and January 2020. Patients who were operated due to intra-abdominal malignancies were searched retrospectively. Among those patients, concomitant splenectomy cases were filtered for the study. The patients' general clinicopathological characteristics were retrieved from their medical records. Patients were divided into two groups, according to the objectives. The clinicopathological differences between the groups were evaluated with appropriate statistical tests, assuming significant p value of less than 0.05. The study included 45 patients. The mean age of the patients was 62.84 ± 12.59 (30-86 years), and male to female ratio was 19:26. Splenectomy was performed during gastric cancer surgery in 30 patients (66.7%) and 43 patients (95.6%) were operated in elective conditions. There was a need for more erythrocyte suspension in patients, who underwent splenectomy during gastric cancer surgery (p=0.040). However, length of hospital stay and overall morbidity were higher at splenectomy with extra-gastric cancer group, (p = 0.036 and p = 0.011, respectively). Splenectomy during gastric cancer surgery is more demanding; and requires more erythrocyte suspension. However, these patients had less morbidity tendencies. Length of stay was longer with splenectomy during extra-gastric abdominal cancer group. Splenectomy, Gastric cancer, Length of stay, Morbidity.

Distribution of pre- and mid-pandemic transfusions by blood types

Introduction: COVID-19 disease spread rapidly worldwide, causing a pandemic. In this study, we aimed to explore the distribution of blood products in our blood center before and during the pandemic by blood type.&#x0D; Material and Method: In this study, we retrospectively analyzed 4,271 blood products (1,290 patients) transfused before and during the pandemic through the medical records of Kastamonu Training and Research Hospital Blood Transfusion Center. Moreover, we investigated the associations between transfusions and age, sex, blood type, and COVID-19 infection.&#x0D; Results: The findings revealed that the majority of the patients receiving transfusions both before and during the pandemic were A Rh (+) (41.4%). Besides, the rates of those with O Rh (+) were 28.8% and 28.7% during the pandemic. In addition, 37 products (28 erythrocyte suspensions, 7 fresh frozen plasma, 2 pooled platelet suspensions) were transfused on 17 patients with confirmed COVID-19.&#x0D; Conclusion: Transfusions have an important place in the treatment of critically ill patients. The blood type A Rh (+) was previously shown to be associated with an increased risk of COVID-19 infection. In this study, although we realized that products of blood type A were mostly used in general transfusions, transfusions in the pandemic were performed predominantly with blood products of infected patients with blood type O. The modern world is more likely to encounter further pandemics in the future. We think that each region should evaluate its own centers.

Impact of Preoperative Embolization on Carotid Body Tumor Surgery

The aim of this study is to investigate the effect of preoperative carotid body tumor embolization (CBTE) on the amount of bleeding, and vascular and neurological complications in carotid body tumors. Fifty patients treated for 51 carotid body tumors in 2 clinics, between 2005 and 2020, were evaluated. Polyvinyl alcohol embolization of the carotid body tumor was performed in 23 patients before the surgical excision. The results were compared with the remaining 28 patients, in whom CBTE was not performed, in terms of neurological complications, requirement of additional vascular interventions, bleeding amount, and length of hospital stay. Mean bleeding amount was significantly lower in the CBTE group (406-217mL, P<0.05). Median erythrocyte suspension transfusion was significantly lower in the CBTE group (0.3 units vs. 1.1 units, P<0.05). Neurological deficits developed in a total of 13 patients: 6 in the CBTE group and 7 in the non-CBTE group, in the early postoperative period (P=0.90). No significant difference was observed between the groups in terms of additional vascular interventions and length of hospital stay (P=0.79 and P=0.61). Carotid body tumors are rarely encountered tumors. However, their surgical excision is challenging for surgeons regarding intraoperative and postoperative bleeding. This study demonstrates that preoperative CBTE significantly reduces the amount of bleeding, especially in Shamblin type II/III tumors.

Semi-refined carrageenan induces eryptosis in a Ca&lt;sup&gt;2+&lt;/sup&gt;-dependent manner

Background: Semi-refined carrageenan (food additive E407a) is a widely used thickener, which has been reported to exert toxic and pro-inflammatory effects. In particular, there is accumulating evidence that it induces eryptosis, i.e. a programmed cell death of eryptocytes, via ROS-mediated pathways. However, the role of Ca2+-dependent mechanisms in E407a-induced eryptosis is not elucidated. Material and methods: Semi-refined carrageenan at concentrations of 0 mg/ml, 1 mg/ml, 5 mg/ml and 10 mg/ml was incubated with blood of intact female WAG rats (n=9) for 24 h in RPMI and fetal bovine serum. After 24 h, the samples were used to obtain erythrocyte suspensions. The obtained suspensions were stained with a Ca2+-sensitive FLUO4 AM probe (30 min, 2.5 µM). The fluorescence of FLUO4 in erythrocytes was detected by a BD FACSCanto II flow cytometer. Results: The intracellular Ca2+ levels are proportional to the fluorescence of FLUO4. The mean fluorescence intensities (MFI) were compared. Low levels (1 mg/ml) of E407a had no impact on Ca2+ concentrations in erythrocytes (p>0.05). On the contrary, high concentrations (5 mg/ml and 10 mg/ml) of this food additive promoted an increase in the intracellular Ca2+ levels. The MFI values were 2.3- and 2.5-fold higher, respectively (p<0.0001). In addition, the exposure to E407a at concentrations of 5 mg/ml and 10 mg/ml (p<0.0001) increased the percentage of cells with high FLUO4 fluorescence. Conclusion: Food additive E407a induces eryptosis in a Ca2+-dependent manner.

Erythrocyte sedimentation: Effect of aggregation energy on gel structure during collapse.

The erythrocyte (or red blood cell) sedimentation rate (ESR) is commonly interpreted as a measure of cell aggregation and as a biomarker of inflammation. It is well known that an increase of fibrinogen concentration, an aggregation-inducing protein for erythrocytes, leads to an increase of the sedimentation rate of erythrocytes, which is generally explained through the formation and faster settling of large disjoint aggregates. However, many aspects of erythrocyte sedimentation conform well with the collapse of a particle gel rather than with the sedimentation of disjoint aggregates. Using experiments and cell-level numerical simulations, we systematically investigate the dependence of ESR on fibrinogen concentration and its relation to the microstructure of the gel-like erythrocyte suspension. We show that for physiological aggregation interactions, an increase in the attraction strength between cells results in a cell network with larger void spaces. This geometrical change in the network structure occurs due to anisotropic shape and deformability of erythrocytes and leads to an increased gel permeability and faster sedimentation. Our results provide a comprehensive relation between the ESR and the cell-level structure of erythrocyte suspensions and support the gel hypothesis in the interpretation of blood sedimentation.

Nonhemolytic Listeria monocytogenes-Prevalence Rate, Reasons Underlying Atypical Phenotype, and Methods for Accurate Hemolysis Assessment.

Listeria monocytogenes is a foodborne pathogen that typically presents β-hemolytic activity. However, there are literature reports indicating that L. monocytogenes strains are sometimes nonhemolytic or their zones of hemolysis are perceivable only after removal of the colonies from the agar plate. Nonhemolytic L. monocytogenes are most commonly encountered in food products, but some have also been detected in clinical samples. Usually, atypical bacteria of this species belong to serotype 1/2a. Mutations of the prfA gene sequence are the most common reason for changed phenotype, and mutations of the hly gene are the second most common cause. There are also reports that the methodology used for detecting hemolysis may influence the results. Sheep or horse blood, although most commonly used in modern studies, may not allow for the production of clear hemolytic zones on blood agar, whereas other types of blood (guinea pig, rabbit, piglet, and human) are more suitable according to some studies. Furthermore, the standard blood agar plate technique is less sensitive than its modifications such as bilayer or top-layer (overlay) techniques. The microplate technique (employing erythrocyte suspensions) is probably the most informative when assessing listerial hemolysis and is the least susceptible to subjective interpretation.

On the Nature of the Spectral Shift of the Soret Band of Erythrocyte Oxyhemoglobin when Organic Molecules Are Added to an Erythrocyte Suspension

On the Nature of the Spectral Shift of the Soret Band of Erythrocyte Oxyhemoglobin when Organic Molecules Are Added to an Erythrocyte Suspension

UNILATERAL ANTEGRADE CEREBRAL PERFUSION VERSUS DEEP HYPOTHERMIC CIRCULATORY ARREST DURING ACUTE AORTIC DISSECTION REPAIR: A SINGLE CENTER EXPERIENCE.

The gold standard of circulation strategy and arterial cannulation during acute aortic dissection is still indisputable. Unilateral/bilateral antegrade cerebral perfusion (UACP/BACP) and deep hypothermic circulatory arrest (HCA) remains a safe and useful procedure for circulation during management of acute aortic dissection. The aim of our study was to investigate the effectiveness of both unilateral antegrade cerebral perfusion and deep hypothermic circulatory arrest on postoperative outcomes during management of acute aortic dissection repair at our center. Our prospective study consisted of 26 patients who underwent acute aortic dissection repair with various circulation strategy. Group A consisted of 14 (53.8%) patients who were operated on under unilateral antegrade cerebral perfusion, while group B consisted of 12 (46.2%) patients who were operated on under deep hypothermic circulatory arrest without cerebral perfusion. Postoperative outcomes included mortality, drainage, blood transfusion (free frozen plasma, erythrocyte suspension), ventilation time and revision due to bleeding. The average age of our study population was 55.2 ± 16.2 (range 33-83) years. Mortality was observed in 3 (11.5%) of our patients. There was no significant difference between the groups in terms of mortality and revision due to bleeding (p ˃ 0.05). Blood transfusion (erythrocyte suspension and free frozen plasma), drainage and ventilation time were significantly lower in Group A compared with Group B (p ˃ 0.05). Both unilateral antegrade cerebral circulation and deep hypothermic circulatory arrest can be safely used during acute aortic dissection, although unilateral antegrade cerebral circulation has proved to be superior over deep hypothermic circulatory arrest with good postoperative outcomes.