It has been long known that blood health heavily influences optimal physiological function. Abnormalities affecting the physical properties of blood have been implicated in the pathogenesis of various disorders, although the exact mechanistic links between hemorheology and clinical disease manifestations remain poorly understood. Often overlooked in current medical practice, perhaps due to the promises offered in the molecular and genetic era, the physical properties of blood which remain a valuable and definitive indicator of circulatory health and disease. Bridging this gap, the current manuscript provides an introduction to hemorheology. It reviews the properties that dictate bulk and microcirculatory flow by systematically dissecting the biomechanics that determine the non-Newtonian behavior of blood. Specifically, the impact of hematocrit, the mechanical properties and tendency of red blood cells to aggregate, and various plasma factors on blood viscosity will be examined. Subsequently, the manner in which the physical properties of blood influence hemodynamics in health and disease is discussed. Special attention is given to disorders such as sickle cell disease, emphasizing the clinical impact of severely abnormal blood rheology. This review expands into concepts that are highly topical; the relation between mechanical stress and intracellular homeostasis is examined through a contemporary cell-signaling lens. Indeed, accumulating evidence demonstrates that nitric oxide is not only transported by erythrocytes, but is locally produced by mechanically-sensitive enzymes, which appears to have intracellular and potentially extracellular effects. Finally, given the importance of shear forces in the developing field of mechanical circulatory support, we review the role of blood rheology in temporary and durable mechanical circulatory support devices, an increasingly utilized method of life support. This review thus provides a comprehensive overview for interested trainees, scientists, and clinicians.

Background and aims: Internet gaming disorder (IGD) is an emerging problem. Rarely, media reports about people, who have died during playing video games, but thus far no systematic, scientific study is available about the topic. We investigated such cases, looking for common characteristics, connection between gaming and death, and the possible reasons leading to death. Methods: Cases were collected through internet search with general keywords, with ones specific to identified cases, and by working along cross references. Results: 24 cases were found: one from 1982, the others between 2002 and 2021. Twenty-three of the victims were male, age ranged from 11 to 40 years. More than half of the cases originated from Southeast Asia, and 12 deaths happened in internet cafes. Gamers played action-rich multiplayer games. In 18 cases the gaming session before death was extremely long (around a day or even several days) with minimal rest. The cause of death was pulmonary embolism in 5 cases, cerebral hemorrhage in 2 cases, most of the rest was presumably due to fatal cardiac arrhythmia. Discussion: Long sedentary position and dehydration may precipitate thromboembolism, acute blood pressure elevation during gaming may promote cerebral hemorrhage, and several factors (including acute and chronic sleep deprivation, exhaustion, stress) can lead to acute autonomic dysfunction and fatal arrhythmia. Conclusion: Incidence of non-violent death cases linked to playing video games is presumably very low. It mostly occurs in young males and it is often characterized by extremely long gaming time.

Early prediction of the mortality, neurological outcome is clinically essential after successful cardiopulmonary resuscitation. To find a prognostic marker among unselected cardiac arrest survivors, we aimed to evaluate the alterations of the l -arginine pathway molecules in the early post-resuscitation care. We prospectively enrolled adult patients after successfully resuscitated in- or out-of-hospital cardiac arrest. Blood samples were drawn within 6, 24, and 72 post-cardiac arrest hours to measure asymmetric and symmetric dimethylarginine (ADMA and SDMA) and l -arginine plasma concentrations. We recorded Sequential Organ Failure Assessment, Simplified Acute Physiology Score, and Cerebral Performance Category scores. Endpoints were 72 h, intensive care unit, and 30-day mortality. Among 54 enrolled patients [median age: 67 (61–78) years, 48% male], the initial ADMA levels were significantly elevated in those who died within 72 h [0.88 (0.64–0.97) µmol/L vs. 0.55 (0.45–0.69) µmol/L, p = 0.001]. Based on receiver operator characteristic analysis (AUC = 0.723; p = 0.005) of initial ADMA for poor neurological outcome, the best cutoff was determined as > 0.65 µmol/L (sensitivity = 66.7%; specificity = 81.5%), while for 72 h mortality (AUC = 0.789; p = 0.001) as > 0.81 µmol/L (sensitivity = 71.0%; specificity = 87.5%). Based on multivariate analysis, initial ADMA (OR = 1.8 per 0.1 µmol/L increment; p = 0.002) was an independent predictor for 72 h mortality. Increased initial ADMA predicts 72 h mortality and poor neurological outcome among unselected cardiac arrest victims.

Introduction: We investigated the associations of cell death-related release of cytokeratin-18 (CK-18) and its caspase-cleaved form (CCCK-18) with outcomes, clinical parameters, and neuron-specific enolase (NSE) among cardiac arrest (CA) victims. Methods : We determined CK-18, CCCK-18, and NSE plasma concentrations within 6, at 24, and 72 post-CA hours of 54 successfully resuscitated patients. Baseline characteristics, laboratory, vital parameters, prognostic scores were recorded. The follow-up was 30 days. Results : Neither the absolute values of CK-18, CCCK-18, CCCK-18/CK-18 ratio, or NSE, nor their kinetics showed significant difference according to survival and neurological outcome. CK-18 decreased in good renal function in contrast to renal failure. Lactate levels were increased in non-survivors and poor neurological outcomes. In receiver operator characteristic (ROC) analyses lactate was comparable with prognostic scores in predicting 30-day mortality and neurological outcome. The ROC curve of initial lactate indicated a cut-off as 4.90 mmol/L to predict 30-day mortality (specificity=80%; sensitivity=74%) and 6.00 mmol/L (specificity=80%; sensitivity=84%) for poor neurological outcome. Conclusion : This study was the first to investigate the post-resuscitation prognostic value of CK-18 and CCCK-18 with NSE. Although we could not prove their prognostic value, we confirmed the role of initial lactate in predicting mortality and neurological outcome in unselected resuscitated patients.

We investigated peripartum maternal red blood cell (RBC) properties in early-onset preeclampsia (PE). Repeated blood samples were taken prospectively for hemorheological measurements at PE diagnosis (n = 13) or during 26–34 weeks of gestation in healthy pregnancies (n = 24), then at delivery, and 72 h postpartum. RBC aggregation was characterized by M index (infrared light transmission between the aggregated RBCs in stasis) and aggregation index (AI—laser backscattering from the RBC aggregates). We observed significantly elevated RBC aggregation (M index = 9.8 vs. 8.5; AI = 72.9% vs. 67.5%; p < 0.001) and reduced RBC deformability in PE (p < 0.05). A positive linear relationship was observed between AI and gestational age at birth in PE by regression analysis (R2 = 0.554; p = 0.006). ROC analysis of AI showed an AUC of 0.84 (0.68–0.99) (p = 0.001) for PE and indicated a cutoff of 69.4% (sensitivity = 83.3%; specificity = 62.5%), while M values showed an AUC of 0.75 (0.58–0.92) (p = 0.019) and indicated a cutoff of 8.39 (sensitivity = 90.9% and specificity = 50%). The predicted probabilities from the combination of AI and M variables showed increased AUC = 0.90 (0.79–1.00) (p < 0.001). Our results established impaired microcirculation in early-onset PE manifesting as deteriorated maternal RBC properties. The longer the pathologic pregnancy persists, the more pronounced the maternal erythrocyte aggregation. AI and M index could help in the prognostication of early-onset PE, but further investigations are warranted to confirm the prognostic role before the onset of symptoms.

Introduction: Cytokeratin-18 (CK-18) is releasing into the blood during systemic cell death due to ischemia-reperfusion injury after cardiac arrest. Its caspase-cleaved form is specific to apoptosis. Previous investigations proved their prognostic value in different conditions. We firstly investigated the prognostic value of these markers after cardiac arrest. Method: Plasma samples of 40 resuscitated patients were collected 6, 24, and 72 hours after successful resuscitation to determine the marker concentrations. We investigated the association of the markers with the 30-day mortality, neurological outcome, circumstances of the cardiac arrest, laboratory and physical parameters. Results: Resuscitated patients had highly elevated CK-18 levels (3842 vs. 242; 559; 1644 ng/L) and decreased caspase-cleaved CK-18/CK-18 ratio (0.14 vs. 0.58; 0.22; 0.24) compared to healthy subjects, septic and postoperative patients suggesting severe grade of cell death, mainly necrosis. Neither the marker concentrations nor their kinetics showed difference between survivors and non-survivors. They did not show association with the length of the resuscitation, the initial rhythm or the neurological outcome either. CK-18 decreased in patients with good renal function in contrast to patients with renal failure. Significant negative correlation was observed between the 6-hour cytokeratin-18 and hemoglobin concentrations (r = -0.400, p<0.01), while the 30-day survival was associated with lower hemoglobin levels. Conclusion: Surprisingly the biomarkers did not show prognostic value among resuscitated population. The outcome is probably not determined by the complete cell damage, but the loss of a small group of cells with critical role and the reserve capacity of the patient. Orv Hetil. 2020; 161(1): 26-32.

Objectives. Several beneficial effects of resveratrol have already been published. This study evaluated the effect of resveratrol on the hemorheological parameters in patients with heart failure with reduced ejection fraction. Methods. In our double-blind, placebo-controlled human clinical trial, we enrolled 60 outpatients with heart failure. Patients were randomized into two groups: receiving either 100 mg resveratrol capsule daily or placebo for 3 months. Hematocrit was determined by microhematocrit centrifuge. Plasma and whole blood viscosity was evaluated by capillary viscometer. Erythrocyte aggregation was measured by both LORCA and Myrenne aggregometers. LORCA ektacytometer was used for measuring erythrocyte deformability. Exercise capacity was assessed by a 6-minute walk test. Results. Resveratrol treatment did not have any significant effect on hematocrit and viscosity. The erythrocyte deformability also remained unchanged. However, significant improvement of red blood cell aggregation was observed in the resveratrol group compared to baseline after 3 months. Furthermore, positive correlation was found between the exercise capacity and the hemorheological properties (Hct, WBV, and RBC aggregation and deformability) as well. Conclusion. These findings indicate that resveratrol can significantly reduce red blood cell aggregation, which may positively influence microcirculation, which may contribute to the improvement of tissue perfusion and oxygen supply in heart failure.

Absztrakt: Bevezetés: Citokeratin-18 (CK-18) az újraélesztés kapcsán kialakuló ischaemiás-reperfúziós károsodás kiváltotta teljes sejthalál során kerül a véráramba. Kaszpázok által hasított formája specifikus az apoptózis folyamatára. A markerek számos kórképben prognosztikus értékűnek bizonyultak. Tanulmányunkban elsőként vizsgáltuk prognosztikus értéküket reanimált betegpopulációban. Módszer: 40, sikeresen újraélesztett betegnél határoztuk meg a sejthalálmarkerek szintjét 6 órán belül, 24 és 72 óra múlva. Ezeket összevetettük a 30 napos túléléssel, a neurológiai kimenetellel, a szervfunkciós károsodást jellemző laboratóriumi, fizikális és terápiás jellemzőkkel, valamint a reanimáció körülményeivel. Eredmények: A reanimált betegek CK-18-plazmakoncentrációja a szakirodalomban leírt egészséges, posztoperatív és szeptikus populáció értékeinek a többszöröse volt (3842 vs. 242; 559; 1644 ng/l); a hasított és intakt CK-18 aránya alacsonyabb volt (0,14 vs. 0,58; 0,22; 0,24), ami jelentős sejtkárosodásra és a nekrózis dominanciájára utal. A markerek szintje azonban nem mutatott összefüggést a túléléssel, a neurológiai statusszal és a reanimáció körülményeivel sem. Veseelégtelenség esetén a CK-18 szintjének csökkenése elmaradt. Szignifikáns negatív korrelációt figyeltünk meg a 6 órás hemoglobin- és CK-18-szint között (r = –0,400, p<0,01), a 30 napos túlélésnek mégis az alacsonyabb hemoglobinértékek kedveztek. Következtetés: Várakozásunkkal ellentétben a vizsgált markerek nem bírtak prognosztikus értékkel újraélesztett betegpopulációban. A kimenetelt valószínűleg nem a teljes sejtkárosodás, hanem egy kisebb, a fenti markerekkel szenzitíven nem vizsgálható kritikus szerepű sejtpopuláció károsodása, valamint a beteg tartalékkapacitásai befolyásolják. Orv Hetil. 2020; 161(1): 26–32.

INTRODUCTION: Hemorheology is the study of the flow properties of the blood and its elements, which, together with natural anticoagulants, are important determinants of cardiovascular events. This study aimed to assess hemorheological and natural anticoagulant profiles of patients with celiac disease (CeD) comprehensively. METHODS: Our study is a case-control study (registered under ISRCTN49677481) comparing patients with CeD with age- and sex-matched control subjects (1:1). We measured erythrocyte deformability (ED) at high (3–30 Pa) and low shears (0.3–3 Pa), erythrocyte aggregation, whole blood viscosity, plasma viscosity, and natural anticoagulants (protein C, protein S, and antithrombin activity). Adherence to gluten-free diet was estimated through dietary interview and urine gluten immunogenic peptide (urine GIP) detection. RESULTS: After matching, we analyzed the data of 100 study participants. ED at high shears was impaired in CeD ( P < 0.05 for all shears, confirmed by random forest analysis) independently of findings on CeD-specific serological assessment and urine GIP detection but slightly dependently on dietary adherence ( P = 0.025 for 30 Pa shear). ED at low shears seemed to be impaired only in urine GIP+ CeD patients ( P < 0.05 for all comparisons with urine GIP− CeD patients and control subjects). All parameters describing erythrocyte aggregation and whole blood viscosity were shifted toward a prothrombotic direction in patients with CeD with poor dietary adherence compared with those with good dietary adherence. Plasma viscosity and activity of natural anticoagulants did not differ across groups. DISCUSSION: We observed diet-dependent and diet-independent prothrombotic hemorheological alterations in CeD, which can contribute to the elevated cardiovascular risk. The untoward metabolic changes during gluten-free diet, which can further aggravate hemorheological status, may indicate the implementation of prevention strategies. JOURNAL/cltg/04.03/01720094-202011000-00009/inline-graphic1/v/2023-10-30T213702Z/r/image-tiff

Introduction Haemorheological and haemostatic changes predispose to the development of arterial and venous thrombotic events; however, limited information is available on the status of these changes in coeliac disease (CeD) and inflammatory bowel disease (IBD). In this study, we aim to describe the haemorheological and haemostatic profiles of CeD and IBD patients in a Hungarian cohort of patients to investigate whether any alterations contribute to elevated thrombotic risk. Methods and analysis This is a case–control study involving newly diagnosed and followed CeD and IBD patients with age-matched and sex-matched non-CeD, non-IBD subjects with an allocation ratio of 1:1:1. After informed consent is obtained, a detailed medical history will be collected, including venous and arterial thrombotic risk factors and medications. Symptoms in CeD patients will be assessed with the Gastrointestinal Symptoms Rating Scale, and disease activity in IBD patients will be determined by disease-specific scores. Dietary adherence will be assessed among CeD patients with a thorough interview together with a measurement of self-reported adherence, dietary knowledge and urine analysis (detection of gluten immunogenic peptides). In addition to routine laboratory parameters, haemorheological (ie, erythrocyte deformability and aggregation, viscosity of whole blood and plasma) and haemostatic parameters (eg, protein C, protein S and antithrombin) with immunological indicators (ie, coeliac-specific serology and antiphospholipid antibodies) will be measured from venous blood for every participant. Primary and secondary outcomes will be haemorheological and haemostatic parameters, respectively. Univariate and multivariate statistics will be used to compare CeD and IBD patients to control subjects. Subgroup analysis will be performed by disease type in IBD, (Crohn’s disease and ulcerose colitis), dietary adherence in CeD, and disease activity in IBD and CeD. Ethics and dissemination The study was approved by the Regional and Local Research Ethics Committee, University of Pécs (Ref. No. 6917). Findings will be disseminated at research conferences and in peer-reviewed journals. Trial registration number ISRCTN49677481.

Introduction: Ischemia-reperfusion injury during and after resuscitation from cardiac arrest results in increased systemic cell death. Cytokeratin-18 (CK-18) is released into the blood during cell death, its caspase cleaved form (ccCK-18) is specific to apoptosis. This study evaluates their prognostic value for mortality, neurological outcome and their association with conventionally used clinical parameters after successful cardiopulmonary resuscitation (CPR).

BACKGROUND:Viscosity measurement is challenging due to the internal properties of blood and the artifacts deriving from the various viscometer systems.OBJECTIVE:We aimed to determine the pitfalls of a cone-plate viscometer (Brookfield DV-III Ultra LV) before starting measurements and compare it to our capillary type model (Hemorex Hevimet 40). Effects of sample storage and thermal calibration were assessed as well.METHODS AND RESULTS:Intra-observer variability was studied by 10 replicate measurements of 7 blood samples, mean coefficients of variation were less than 5%. Instruments were compared by measuring 26 blood samples, an average difference of 7% in WBV and 10% in PV was observed. 9 blood samples were stored at 4°C, 22°C and 37°C up to 48 hours to study the effect of storage on viscosity values. WBV at 50 and 100 s-1 became significantly lower after 3 hours at 37°C (p < 0.05). WBV at higher shear rates and PV remained constant at all temperatures. To evaluate the possibility of measuring one sample at different temperatures, 8 blood samples were measured at 40°C with the device calibrated both at 20°C and 40°C; no significant difference was observed.CONCLUSIONS:Thorough validation studies are required before starting experimental and routine viscosity measurements.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Objective: SPECT/CT has numerous advantages over planar and traditional SPECT images. The aim of this study was to evaluate the role of post-radioiodine therapy SPECT/CT of patients with differentiated thyroid cancer (DTC) in early risk classification and in prediction of late prognosis. Patients and methods: 323 consecutive patients were investigated after their first radioiodine treatment (1100-3700 MBq). Both whole body scan and SPECT/ CT images of the head, neck, chest and abdomen regions were taken 4-6 days after radioiodine therapy. Patients were re-evaluated 9-12 months later as well as at the end of follow up (median 37 months). Results: Post-radioiodine therapy SPECT/CT showed metastases in 22% of patients. Lymph node, lung and bone metastases were detected in 61, 13 and 5 patients, respectively, resulting in early reclassification of 115 cases (36%). No evidence of disease was found in 251 cases at 9-12 months after radioiodine treatment and 269 patients at the end of follow-up. To predict residual disease at the end of follow-up, the sensitivities, specificities and diagnostic accuracies of the current risk classification systems and SPECT/CT were: ATA: 77%, 47% and 53%; ETA: 70%, 62% and 64%; SPECT/CT: 61%, 88% and 83%, respectively. There was no difference between cohorts of the two institutions when data were analyzed separately. Conclusions: Based on our bi-institutional experience, the accuracy of postradioiodine SPECT/CT outweighs that of the currently used ATA and ETA risk classification systems in the prediction of long-term outcome of DTC.

PURPOSE:The prognostic scoring systems for mortality of intensive care patients estimate clinical outcome using several physiological and biochemical parameters. In altered hemodynamic conditions of critically ill patients, hemorheological variables may play a significant role in appropriate tissue perfusion. We investigated if hemorheological parameters are altered in critical status and if they could be markers of mortality.METHODS:112 patients (67.8 ± 12 years, 58 males, 54 females) treated in intensive care unit with different non-surgical diseases were investigated. Routine laboratory parameters and prognostic scores were determined and hemorheological variables (hematocrit, plasma and whole blood viscosity, red blood cell aggregation and deformability) were measured on the 1st and the 2nd day after admission.RESULTS:ICU scores predicted 35.2-41.3% mortality rate, real mortality in intensive care unit was 37.5%, while 30-day mortality was 46.6%. Whole blood viscosity (WBV) and red blood cell (RBC) deformability were lower, red blood cell aggregation was higher in septic than in nonseptic patients (p < 0.05). In septic patients calcium was increased, osmolality was decreased, while in nonseptic patients WBV and RBC aggregation were higher in nonsurvivors compared to survivors (p < 0.05). Worsening of RBC deformability from day 1 to day 2 predicted higher mortality (p < 0.05).CONCLUSION:Calcium and osmolality level were associated with outcome in sepsis. Whole blood viscosity, red blood cell aggregation and change in red blood cell deformability could predict mortality in nonseptic patients and they may add prognostic information over the ICU scores. Further investigations are needed to evaluate the benefit of our findings in clinical practice.

BACKGROUND:Carotid artery stenosis (CAS) is not only an important risk factor of cerebrovascular events but it can also indicate generalized atherosclerosis. Hemorheological parameters are altered in CAS and in chronic cerebrovascular disorders as well, but it is controversial if hemorheological parameters could be markers of stenosis or atherosclerosis.METHODS:107 patients were investigated, 40% of them had stroke or TIA in case history and 48% had CAS. Routine lab parameters were determined and hemorheological variables were measured: hematocrit, plasma viscosity, whole blood viscosity, red blood cell aggregation, and deformability.RESULTS:In the stenotic group whole blood viscosity and red blood cell aggregation were deteriorated (p < 0.05). Whole blood and plasma viscosity were higher and red blood cell deformability was lower in the symptomatic group (p < 0.05). Plasma viscosity and red blood cell deformability were altered in the evolving atherosclerosis group and the CAS groups compared to patients having no signs of stenosis (p < 0.05), but there was no difference among the CAS groups.CONCLUSION:Although hemorheological parameters are impaired both in CAS and chronic cerebrovascular disorders, the severity of stenosis cannot be detected based on hemorheological parameters. Our investigation suggests that alteration of hemorheological parameters could indicate carotid atherosclerosis.