bluuebunny/crossref_metadata_2025 huggingface dataset:
Nailfold capillaroscopy: Specific features in Fabry disease
Authors: Wasik Jan S. , Simon Roger W. , Meier Thomas , Steinmann Beat , Amann-Vesti Beatrice R.
Published: December 2019

Objective: Fabry disease is a rare X-linked disorder caused by deficiency of α-galactosidase A. The metabolic defect results in the progressive accumulation of globotriaosylceramide within vascular cells leading to renal, cardiac and cerebrovascular manifestations. The aim of this study was to evaluate nailfold capillaroscopy as a non-invasive diagnostic tool in Fabry disease and to characterize morphological and functional changes of the capillaries in vivo.

Methods: Twenty-five consecutive patients with Fabry disease (17 males) without enzyme-replacement therapy had been studied by fluorescence nailfold capillaroscopy. Macrocirculation of digital arteries was tested by digital pulse volume recording and patients had been asked about the presence of Raynaud phenomenon.

Results: Significant more bushy capillaries and clusters were present in Fabry patients (72%) compared to healthy controls (10%). No avascular fields had been seen, and in only one patient atypical architecture and in another one a giant capillary was present. Enhanced natrium-fluorescein diffusion into the pericapillary area has been observed in three male patients. Six patients (one female) reported Raynaud phenomenon of all fingers.

Conclusions: In Fabry disease morphological and functional microangiopathy of nailfold capillaries is present. Furthermore, these new findings might explain, at least in part, the unusual high frequency of Raynaud phenomenon in Fabry patients, which has not been described so far. Our data suggest that capillaroscopy might be used as an additional non-invasive diagnostic tool for Fabry disease.
Imaging of endoleaks after endovascular aneurysm repair (EVAR) with contrast-enhanced ultrasound (CEUS). A pictorial comparison with CTA
Authors: Clevert D.-A. , Minaifar N. , Kopp R. , Stickel M. , Meimarakis G. , Sommer W. , Reiser M.
Published: December 2019

Endoleaks following endovascular aneurysm repair (EVAR) are common and present a diagnostic challenge in the follow-up after EVAR. Contrast-enhanced ultrasound (CEUS) with low mechanical index (low MI) is a promising new method for the diagnosis and follow-up of endoleaks. CEUS with SonoVue® allows a more rapid and noninvasive diagnosis, especially in critical patients owing to its bedside availability. This review describes the etiology, classification and importance of different types of endoleaks and compares CEUS findings with computed tomography angiography (CTA), allowing the reader to appreciate the usefulness of CEUS in this clinical situation.
Effect of hemoglobin oxygenation level on red blood cell deformability and aggregation parameters
Authors: Uyuklu Mehmet , Meiselman Herbert J. , Baskurt Oguz K.
Published: December 2019

Measurements of red blood cell (RBC) deformability and aggregation can be subject to influence by pre-analytical handling procedures, with the degree of hemoglobin oxygenation having the potential to affect the results. To examine such effects, RBC deformability and aggregation were studied before and after oxygenation or deoxygenation of human blood samples. RBC deformability was assessed using a laser-diffraction ektacytometer having Couette geometry. RBC aggregation was assessed using the same system by monitoring light backscattering after a sudden cessation of high shear; aggregation was also measured by monitoring light transmittance through RBC suspensions. RBC deformability was found to be significantly increased after equilibrating RBC with ambient air (pO2: 142.0±3.1 mmHg) compared to the non-oxygenated sample (pO2: 42.4±1.8 mmHg). In contrast, equilibration with 100% nitrogen resulted in significant impairment in RBC deformability. RBC aggregation parameters were also affected by oxygenation if measured based on light backscattering, but not if measured using light transmittance. It is thus recommended that blood samples be oxygenated by repeated exposure to ambient air prior to the measurement of hemorheological parameters.
Red blood cell rheology in patients with chronic venous disease (CVD)
Authors: Chwała Maciej , Spannbauer Anna , Teległów Aneta , Cencora Andrzej , Marchewka Anna , Hardeman Max R. , Dąbrowski Zbigniew
Published: December 2019

Rheological studies concerning aggregation and elongation of erythrocytes were carried out in 21 patients (mean age 56 years) with chronic venous disease (CVD) and 10 (mean age 45 years) healthy control subjects, with the use of a LORCA device. Higher values of parameters characterizing both erythrocyte elongation (EI) and aggregation (γthr) in non-control patients than in the control group were found. These values differed significantly ranging from 1.13 to 8.23 Pa for the shear stress and γthr in patients – 432.14, in relation to the control group – 166.5. It was proposed, that the increase in deformability may constitute a compensatory mechanism in subjects with chronic venous disease, due to increased resistance in their microcirculation.
Measurement of erythrocyte aggregation in a microchip stirring system by light transmission
Authors: Shin Sehyun , Yang Yijie , Suh Jang-Soo
Published: December 2019

In the analysis of red blood cell (RBC) aggregation using optical detection, various shearing methods have been used to disperse RBCs in confined geometries. This study investigated RBC aggregation measurement in a microchip-stirring system by analysis of light transmission. A stirring-aided disaggregation mechanism in a microchip, consisting of a flat-cylindrical test chamber (D=4 mm, H=0.3 mm) and a magnetic stirrer (d=0.14 mm, l=2.2 mm), was used to generate a given shear which was large enough to disperse RBC aggregates, but not large enough to cause any mechanical hemolysis of cells. After stirring for 10 s followed by an abrupt halt of the stirring, the intensity of the light transmitted through a microchip was measured with respect to time and analyzed. A comparative study was conducted with varying test chamber height and hematocrit. The AI and t1/2 as typical aggregation indices obtained by analysis of transmitted light, which showed a good reproducibility (coefficient of variation (CV)<2.8%, n=10), also were found to be nearly independent of the chamber dimensions (CV<3.4%). The present aggregometry also showed the similar results of aggregation indices with varying hematocrits compared to those obtained using a laser-assisted optical rotational cell analyzer (LORCA). The essential feature of the present design is the adoption of a disposable microchip requiring a minimum blood sample volume as small as 6 μl, which enables it to be used easily in a clinical setting.
A transient, microfluidic approach to the investigation of erythrocyte aggregation: The threshold shear-stress for erythrocyte disaggregation
Authors: Shin Sehyun , Nam Jeong-Hoon , Hou Jian-Xun , Suh Jang-Soo
Published: December 2019

Detailed analysis of red blood cells (RBCs) aggregation is often required in various clinical studies. Most conventional aggregation indices are dimensionless values and not available for comparison of across studies. Quite recently, we have developed microfluidic aggregometry that enables us to yield a critical shear-stress that are required to aggregate RBCs under the shearing hydrodynamic force. The present study investigated the relationships between the values of the critical shear-stress and conventional aggregation indices by comparing the critical shear-stress measured by the microfluidic aggregometry with the threshold shear-stress measured using a LORCA aggregometer. The results showed that the critical shear-stress did not vary with the hematocrit value while the threshold shear-rate decreased with the hematocrit value. The threshold shear-stress also showed the same hematocrit-independence as the critical shear-stress. These findings assist in rheologically validating the critical shear-stress, as defined in the microfluidic aggregometry, within the present range of hematocrit values.
Ultrasound contrast agents as markers of vascularity and microcirculation
Authors: Greis Christian
Published: December 2019

Ultrasound contrast agents contain tiny gas-filled microbubbles which on intravenous injection are transported like red blood cells by the bloodstream. They are distributed to the entire macro- and microvascular system without extravasation (blood-pool tracer). Contrast-specific ultrasound modalities allow selective imaging of these microbubble contrast agents in real time, with excellent separation from underlying tissue signals. The dynamic wash-in and wash-out of a contrast bolus allows the detection and quantitative assessment of vascular flow and parenchymal perfusion. On complete filling of vascular structures the microbubble distribution delineates the vascular lumen and depicts the vascular architecture, down to tiny branches within parenchymal tissue. Mathematical models for bolus kinetics and flash/replenishment kinetics allow precise quantification of relative blood volume and blood flow, with high temporal and spatial resolution. Contrast-enhanced ultrasound examinations can be repeated at short intervals and performed at the bedside, making this diagnostic method convenient for guidance of interventions and therapy monitoring. Future applications include the use of microbubbles as target-specific molecular imaging agents and as delivery systems for local drug and gene therapies.
Echinocytosis in athletes with exercise-induced hypoxemia
Authors: Connes Philippe , Boucher John H.
Published: December 2019

Abnormal hemorheology has been proposed previously as a possible genesis of exercise-induced hypoxemia (EIH) in humans. This study, in support of the hemorheological hypothesis, aims at determining if red blood cell shape changes might be related to EIH. Three groups of subjects: one without EIH (n=5); one developing mild-EIH (n=7); and, one with moderate EIH (n=5). Each group performed a progressive and maximal exercise test on cycle-ergometer. We evaluated the percent of stomatocytes, echinocytes and schizocytes in blood smears prepared from phlebotomy samples taken at rest and at maximal exercise. The percent of schizocytes or stomatocytes was not different between the three EIH groups at rest; and, exercise produced no change from the resting values of those cell types. The percent of echinocytes was not different between the three EIH groups at rest, however, exercise significantly increased the percent of echinocytes from the resting value of both the mild- and moderate-EIH groups, while the non-EIH group remained unchanged. We suggested that the rigidity of echinocytes could have contributed to the genesis of EIH.
Erythrocyte deformability in macrocytosis determined by means of ektacytometry techniques
Authors: Vayá Amparo , Bonet Elena , Romagnoli Marco , Nuñez Cornelio , Todoli Jose
Published: December 2019

There is little information regarding the behaviour of red blood cell deformability in macrocytosis. We have determined in 114 patients with macrocytosis (MCV > 97 fL) and in 115 age and sex-matched subjects with normocytosis (VCM < 97 fL) erythrocyte deformability by means of ektacytometric techniques (Rheodyn SSD) measuring the erythrocyte elongation index (EEI) at 12, 30 and 60 Pa. Patients with macrocytosis showed statistically higher EEI at all the shear stresses tested when compared with controls (p < 0.001). When patients with macrocytosis were classified according to their main diagnosis as hepatic or renal disease, HIV and miscellaneous, 66.7%, 41.7%, 36.7% and 33.3% of patients, respectively, showed a EEI 60 higher than 61.8% (mean value of the control group + 2 SD). Linear regression analysis demonstrates that MCV, bilirubin, triglycerides and alanine aminotransferase were the main variables influencing EEI 60. An increased surface/volume ratio of the red blood cells may be the main cause related with a higher erythrocyte deformability in a relevant percentage of macrocytosis. Further research is required to confirm our findings by designing case-control pathology-specific studies.
Biorheological changes of dendritic cells at the different differentiation stages
Authors: Wang Xianwei , Chen Dan , Zhang Xiaolan , Jia Binbin , Xie Lide , Sun Dagong , Ka Weibo , Yao Weijuan , Wen Zong-Yao
Published: December 2019

The differentiation, maturation and functioning of Dendritic cells (DCs) are dynamic processes. This study investigated the changes of DCs' migration ability and biorheological properties during their differentiation. Transmigration assay showed that, DCs' migration rate was improved significantly as they differentiate (p < 0.05); NSC (Rac1 blocker) treatment could significantly decrease their migration rates (p < 0.05). Confocal images showed that, F-actin uniformly distributed in monocytes; with DC's differentiation, F-actin began to remodel and gather at the site of dendrites; the images presented surface ruffles and uneven sawtooth-like cytoskeletal structures. Fluorescence polarization analysis showed that, membrane fluidity was increased significantly with DC's differentiation (p < 0.05). CD62L was upregulated significantly (p < 0.05) on the third and ninth days. CD2 was upregulated significantly (p < 0.05) until the seventh day. DC's electrophoretic mobility was increased continuously, especially increased significantly from the third day to the fifth day and the final stage (p < 0.05). These results indicate that there are significant changes in the biorheological properties of DCs during their differentiation.
Image fusion with volume navigation of contrast enhanced ultrasound (CEUS) with computed tomography (CT) or magnetic resonance imaging (MRI) for post-interventional follow-up after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinomas (HCC): Preliminary results
Authors: Ross C.J. , Rennert J. , Schacherer D. , Girlich C. , Hoffstetter P. , Heiss P. , Jung W. , Feuerbach S. , Zorger N. , Jung E.M.
Published: December 2019

Aim: The assessment of the immediate post-interventional microcirculation and perfusion following transcatheter arterial chemoembolization (TACE) with new real time imaging fusion technique (VNav) of computed tomography (CT) or magnetic resonance imaging (MRI) with contrast enhanced ultrasound (CEUS) compared to follow-up. Material: Following TACE an image fusion of CEUS with CT or MRI of the liver was performed in 20 patients (18 men, 2 women; age 29–75 years) with confirmed hepatocelluar carcinoma (HCC) to evaluate the post-interventional tumor vascularization and perfusion of HCC tumor lesions. Image fusion with CEUS performed immediately was compared with the result at the end of TACE (DSA), with post TACE CT (non-enhanced CT within 24hours) and with follow up CT (enhanced CT after 6 weeks) after embolization. Ultrasound was performed using a 1–5 MHz multifrequency SonoVue transducer (LOGIQ 9/GE) after a bolus injection of 2–4ml SonoVue® with contrast harmonic imaging (CHI). Thirteen examinations were fused with a contrast enhanced CT, 7 with a MRI performed before TACE. Results: The post-interventional volume navigation image fusion of CT or MRI with CEUS showed differences regarding the residual tumor perfusion compared to other modalities. The correlation (Spearman-test) between the perfusion result at the end of TACE, non-enhanced CT after TACE and image fusion with CEUS was 0.42 and 0.50. The difference between the result at the end of TACE and the fusion with CEUS was significant (p < 0.05, Wilcoxon-test). The correlation between fusion of CEUS with CT/MRI and follow-up CT (after 6 weeks) was 0.64, the difference was not significant (p > 0.05). The differences between native CT within 24 hours after TACE and follow up CT after 6 weeks or fusion of CEUS and CT/MRI were significant (p < 0.05). The inter-observer variability was 0.61 at the end of TACE, 0.58 at non-enhanced CT (within 24 hours), 0.87 at fusion CEUS with CT/MRI and 0.74 at follow up CT after 6 weeks (Cohens Kappa test). Conclusion: Image fusion with volume navigation (VNav) of CEUS with CT or MRI allows an accurate localisation of foci in patients with HCC. This exact mapping permits an easier control and evaluation of the results after TACE. The fusion of CEUS and CT or MRI allows a better evaluation of the microcirculation and the residual tumor perfusion at an earlier point of time than usual modalities of therapy control like non-enhanced CT. This might lead to a more differentiated monitoring of therapy.
Diagnosis, therapy monitoring and follow up of renal artery pseudoaneurysm with contrast-enhanced ultrasound in three cases
Authors: Helck A. , Hoffmann R.T. , Sommer W.H. , Notohamiprodjo M. , Albyaa H. , Reiser M. , Clevert D.A.
Published: December 2019

Purpose: We describe the presentation of renal artery pseudoaneurysm (RAP) in different imaging modalities (CT, DSA, standard US, contrast enhanced ultrasound (CEUS)). In particular the benefit of CEUS with regards to therapy monitoring and follow up care shall be highlighted. Materials and methods: Three patients with renal artery pseudoaneurysm after renal surgery were investigated with CT and/or US (grey-scaled US, color duplex US, CEUS), respectively. The therapy (angiography-coiling) was monitored using contrast-enhanced ultrasound. Results: Accurate diagnosis of RAP in our study was yielded using color duplex US and CEUS. CEUS was very practical for therapy monitoring of coil embolization with the potential of shortening the invasive DSA. Thus, CEUS has potential of radiation dose reduction and the potential of saving coils with the result of cost reduction. Conclusion: CEUS is an appropriate approach for monitoring coil embolization of RAP.
In vivo evaluation of the angiogenic effects of the multiblock copolymer PDC using the hen's egg chorioallantoic membrane test
Authors: Hiebl B. , Mrowietz C. , Goers J. , Bahramsoltani M. , Plendl J. , Kratz K. , Lendlein A. , Jung F.
Published: December 2019

Multiblock copolymers with shape-memory capability attracted tremendous interest as promising candidate materials for smart, degradable implants. In the present study the hen's egg-chorioallantoic membrane test (HET-CAM test) was used to investigate the angiogenic properties of a thermoplastic, biodegradable multiblock copolymer PDC composed of poly(p-dioxanone) hard segments (PPDO) and crystallizable poly(ε-caprolactone) switching segments (PCL), whereby PPDO and PCL homopolymers were investigated as controls. According to our HET-CAM test data, only PDC induced significant microvessel attraction and formation in the contact area of the test specimen after 48hours of incubation showing newly formed blood vessels along the outer edge of the material. In contrast, no newly formed blood vessels were observed around the PPDO or PCL specimen after the same incubation period. These in vivo results indicate that the multiblock copolymer PDC possibly possesses an angiogenic effect and it can induce blood vessel formation in its direct vicinity when it is implanted in vivo.
Blood viscosity changes in slow coronary flow patients
Authors: Ergun-Cagli Kumral , Ileri-Gurel Esin , Ozeke Ozcan , Seringec Nurten , Yalcinkaya Adnan , Kocabeyoglu Sabit , Basar Fatma Nurcan , Sen Nihat , Cagli Kerim , Dikmenoglu Neslihan
Published: December 2019

Microvascular dysfunction is implicated in the pathogenesis of slow coronary flow (SCF), but less attention has been paid to intrinsic properties of blood that can also impair the microcirculatory flow. In this study we aimed to evaluate the blood viscosity focusing on erythrocyte aggregation, erythrocyte deformability and plasma viscosity in SCF. Thirty-three patients with SCF (21 male, 54 ± 12.8 years) and 23 subjects with normal coronary arteries (13 male, 59 ± 10.3 years) were included in the study. Coronary flow was quantified by means of thrombolysis in myocardial infarction (TIMI) frame count and aggregation and deformability of erythrocytes were measured by an ektacytometer. Plasma viscosity was measured by a cone-plate viscometer. Aggregation amplitude (23 ± 3.8 au vs. 15.7 ± 6.1 au, respectively, p < 0.001) and area A index (area above syllectogram) (153.2 ± 30.7 au.s vs. 124.9 ± 49.3 au.s, respectively, p < 0.01) were higher in SCF patients. Aggregation half-time, aggregation index, elongation index and plasma viscosity values were similar between two groups. Correlation analysis revealed a significant relationship between the TIMI frame count for left anterior descending artery and aggregation amplitude in SCF patients (r = 0.679, p < 0.0001). The result of this study reveals changes in erythrocyte aggregation which may contribute to the pathophysiology of SCF. Larger studies are needed to make more robust conclusions on this issue.
The effects of short term recombinant human growth hormone (rhGH) on blood rheology in healthy young males
Authors: Ramos S.B. , Brun J.F. , Gray B. , Rogerson S. , Weatherby R.P. , Tajouri L. , Marshall-Gradisnik S.M.
Published: December 2019

Introduction: It has been shown that growth hormone (GH) exerts regulatory effects on hemorheology and other metabolic functions. GH stimulates the production of insulin-like growth factor I (IGF-I) and GH–IGF-I system has profound effects on body fluid status. There are speculations that GH has become widely used as a performance enhancing drug among athletes of various sports. The present study evaluated the possible hemorheological effects of short term administration of human recombinant growth hormone (rhGH) in healthy young males. Methodology: Thirty young healthy males (27 ± 9) participated in a 29 days study where it was administered either 0.9% sodium chloride or 1 mg of human rhGH from day 1 to day 7. The participants were randomly assigned into either placebo (C) n = 15 or rhGH 1 mg/day (rhGH) group n = 15. This study evaluated plasma fibrinogen levels, red blood cell (RBC) aggregation, deformability and serum IGF-I levels between and within the groups along 29 days. Results: There was a significant increase in erythrocytes aggregation index post injection (day 8), in accordance to an increase in serum IGF-I.
Correlation of conjunctival microangiopathy with retinopathy in type-2 diabetes mellitus (T2DM) patients
Authors: To Wilson J. , Telander David G. , Lloyd Maureen E. , Chen Peter C.Y. , Cheung Anthony T.W.
Published: December 2019

We hypothesized that T2DM vasculopathy can be revealed and quantified in the bulbar conjunctiva prior to its pathologic presentation in the retina. Using computer-assisted intravital microscopy (CAIM), an objective, non-invasive approach can provide a viable complement to retinal fundus photography to possibly screen patients for early signs of real-time, in vivo T2DM vasculopathy. Fundus photography was utilized to determine the retinopathy level (RL) in T2DM patients with non-proliferative diabetic retinopathy (NPDR) and control subjects. CAIM was used to quantify microangiopathy in the bulbar conjunctiva in the same patients, and reported on a severity index (SI). The average RL for the T2DM patients in this study is 19.68 ± 9.91, which differs from control subjects (RL = 10 ± 0.0; p < 0.05). A significant difference in vasculopathy was observed in the conjunctival microcirculation in the same patients (SI = 5.81 ± 1.30) when compared with control subjects (SI = 1.33 ± 1.58; p < 0.05). The results provide evidence that significant vasculopathy had developed in the microcirculation in the bulbar conjunctiva, though diabetic retinopathy had not developed significantly in the same patients – indicative of the presence of a time window for early intervention of T2DM before non-proliferative retinopathy develops, and the real-time availability of the conjunctival microvasculature as an in vivo platform to monitor disease progression.
Measurement of blood coagulation with considering RBC aggregation through a microchip-based light transmission aggregometer
Authors: Lim Hyunjung , Nam Jeonghun , Xue Shubin , Shin Sehyun
Published: December 2019

Even though blood coagulation can be tested by various methods and techniques, the effect of RBC aggregation on blood coagulation is not fully understood. The present study monitored clot formation in a microchip-based light transmission aggregometer. Citrated blood samples with and without the addition of calcium ion solution were initially disaggregated by rotating a stirrer in the microchip. After abrupt stop of the rotating stirrer, the transmitted light intensity over time was recorded. The syllectogram (light intensity vs. time graph) manifested a rapid increase that is associated with RBC aggregation followed by a decrease that is associated with blood coagulation. The time to reach the peak point was used as a new index of coagulation time (CT) and ranged from 200 to 500 seconds in the present measurements. The CT was inversely proportional to the concentration of fibrinogen, which enhances RBC aggregation. In addition, the CT was inversely proportional to the hematocrit, which is similar to the case of the prothrombin time (PT), as measured by a commercial coagulometer. Thus, we carefully concluded that RBC aggregation should be considered in tests of blood coagulation.
Both overall adiposity and abdominal adiposity increase blood viscosity by separate mechanisms
Authors: Brun Jean-Frédéric , Varlet-Marie Emmanuelle , Raynaud de Mauverger Eric , Mercier Jacques
Published: December 2019

While recent studies suggested that both general adiposity and abdominal adiposity are associated with the risk of death and support the use of waist circumference or waist-to-hip ratio (WHR) in addition to body index mass (BMI) in assessing the risk of death, this issue remains cintroversial since most authors conclude that BMI explains almost all the obesity-related risk of diabetes and conary heart disease (CHD). We investigated the separate effects of BMI and WHR on blood rheology in 430 patients attending to a metabolic check-up and exhibiting all the spectrum of age (11–77 yr) and BMI (15–50 kg/m2). BMI and WHR are correlated to each other (r = 0.269; p = 0.009) and are both predictors of blood viscosity (BMI: r = 0.15516; p = 0.004; WHR: r = 0.3638; p = 0.03). However while looking at determinants of viscosity these correlations had not the same meaning. For BMI it was explained by its correlation with plasma viscosity (r = 0.17718; p = 0.00105) and red blood cells (RBC) aggregation (all Myrenne and SEFAM indices with r ranging between 0.226 and 0.430) while these parameters were not correlated to WHR. By contrast WHR was strongly correlated with hematocrit (r = 0.524; p = 0.0003) which was not correlated with BMI. A forward stepwise regression selected WRH as a better predictor of blood viscosity, excluding BMI. Thus both BMI and WHR are associated with increased blood viscosity but these correlations reflect separate mechanisms. These data suggest that both overall adiposity and abdominal adiposity induce hyperviscosity, consistent with epidemiological studies linking the risk of CHD to abdominal adiposity and BMI.
Postoperative sublingual microcirculatory derangement following esophagectomy is prevented with dobutamine
Authors: van Genderen Michel , Gommers Diederik , Klijn Eva , Lima Alex , Bakker Jan , van Bommel Jasper
Published: December 2019

Introduction: Esophagectomy with gastric tube reconstruction is characterized by high postoperative morbidity rates. Recently it was shown that decreased sublingual microvascular blood flow (MBF) preoperatively was associated with increased rate of complications after abdominal surgery. Similar observations in severely septic patients could be treated with dobutamine, independent of cardiac output. Based on these considerations we hypothesized that sublingual MBF derangements are more likely to be found in patients undergoing high risk surgery such as esophagectomy, and if present, might be prevented with administration of low dose dobutamine. Methods: In this single-centre, prospective, double-blinded study, we randomized 20 patients admitted to the Intensive Care Unit following esophagectomy with gastric tube reconstruction into two groups. The intervention group (D) received a small dose of dobutamine (2.5 μg/kg/min) directly postoperative until two days postoperatively, whereas the placebo group (P) received a similar volume of saline. A subset of patients undergoing pancreaticoduodenectomy surgery was included as control group (C) for comparison with the study group. Sublingual MBF was determined one day prior to surgery until two days postoperatively. Results: At the first postoperative day, patients in the esophagectomy/placebo group (P), showed a significant lower microvascular flow index, perfused vessel density and proportion of perfused vessels compared to baseline (p < 0.001) and the pancreaticoduodenectomy group (C) (p < 0.001). Administration of dobutamine significantly prevented the overall decrease in microvascular blood flow the first postoperative day. Conclusion: Postoperative sublingual MBF is markedly impaired in esophagectomy patients compared to patients who underwent a pancreaticoduodenectomy and could be prevented by early administration of a small dose dobutamine.
Concerning the importance of changes in hemorheological parameters caused by acid-base and blood gas alterations in experimental surgical models
Authors: Nemeth Norbert , Miko Iren , Furka Andrea , Kiss Ferenc , Furka Istvan , Koller Akos , Szilasi Maria
Published: December 2019

Acid-base equilibrium and pH of blood have important clinical consequences in numerous diseases and pathophysiological conditions. The micro-rheological parameters of blood, such as red blood cell deformability and red blood cell aggregation are influenced by several metabolic factors, and provide information regarding inflammatory, septic and tissue or organ ischemia-reperfusion processes. Despite the anticipated logical relation of the blood acid-base condition, blood gas parameters and pH to red blood cell deformability and aggregation, controversial data can be found in the literature. Furthermore, related to ischemia-reperfusion hemorheological studies little is known about this issue. In this paper we aimed to thought-provokingly overview some aspect of acid-base changes, blood pH and hemorheological parameters, discussing certain results from ischemia-reperfusion experimental surgical models (local versus systemic changes), laboratory technical and experimental design protocols related to in vitro and in vivo studies.
Videocapillaroscopy study of post traumatic lower limb loss of tissue treated with and without acellular dermal substitute
Authors: Martini Romeo , Andreozzi Giuseppe Maria , Tiengo Cesare , Azzena Bruno , Mazzoleni Francesco
Published: December 2019

A 46 years old male with a post traumatic loss of tissue localized on the anterior surface of the right thigh and knee due to a road accident, was treated with different surgical reconstructive techniques. Combined use of autologous skin graft and acellular dermal substitute Integra® allowed the satisfactory recovery of the patient who was discharged after 82 days from the trauma. To analyse the characteristics and the quality of the healing tissues we performed a videocapillaroscopy study to assess the microcirculatory pattern of the autologous skin grafted on the dermal substitute in comparison with the autologous skin grafted on granulation tissue. The videocapillaroscopy was performed in the zone skin grafted directly on granulation tissue, Zone 1 (Z1); on the region of the lesion in the knee, treated with dermal substitute and autologous skin graft, Zone 2 (Z2), and on the undamaged controlateral knee skin. Zone 3 (Z3). The results showed that the capillary density was similar between Z2 and Z3, while in Z1, the zone skin grafted on the granulation tissue without Integra® the capillary density was significatively reduced. These preliminary observations within the clinical data may be an useful contribute to better understand the tissue healing process.
The effects of exercise in water at 4°C and 25°C on the rheological properties of blood and the composition of fatty acids in the erythrocyte membranes of laboratory rats
Authors: Teległów Aneta , Bilski Jan , Dąbrowski Zbigniew , Marchewka Anna , Jaśkiewicz Jerzy , Gdula-Argasińska Joanna , Głodzik Jacek , Tabarowski Zbigniew , Lizak Dorota
Published: December 2019

The aim of this study was to assess the influence of a single session of maximal exercise performed in water (4°C or 25°C) on blood rheological properties and the composition of fatty acids in the erythrocyte membranes of laboratory rats. This study will permit better understanding of the reactions occurring in the organism during rapid cooling in cold water, especially in regards to the hemorheological and biochemical parameters of blood. When compared to the control group, exercise performed in water at 4°C led to an increase in the elongation index (EI, from 0.30 Pa to 4.24 Pa) with no concurrent changes in erythrocyte aggregation, blood plasma viscosity, and fatty acid composition (saturated, unsaturated, saturated/unsaturated, monounsaturated, polyunsaturated polyunsaturated-n3, polyunsaturated-n6 fatty acids) of the erythrocyte membrane. In rats swimming in water at 25°C, we observed an increase in EI at shear stress from 0.30 Pa to 2.19 Pa, along with a decrease in the half-time of total aggregation when compared to the control group. These changes in erythrocyte rheological properties can be treated as a protective reaction to thermal stress resulting in their improved deformability.
Differential effects of intravenous anesthetics on hepatosplanchnic microcirculation in rats: Sidestream dark-field imaging study
Authors: Turek Zdenek , Lehmann Christian , Parizkova Renata , Samek Jindrich , Kaska Milan , Cerny Vladimir
Published: December 2019

This study aimed to investigate the effects of intravenous anesthetics on hepatosplanchnic microcirculation in laparotomized mechanically ventilated rats using Sidestream Dark-field (SDF) imaging. Thirty male Wistar rats were divided into 5 groups (n = 6 each). All rats were initially anesthetized with 60 mg/kg pentobarbital (i.p.) for instrumentation. This was followed by either ketamine, propofol, thiopental, midazolam or saline+fentanyl (iv bolus over 5 min and then maintenance over 90 min). SDF imaging of the liver and distal ileum microcirculation was performed at the baseline and at t = 5, 35, 65 and 95 min. In propofol group there was increase of functional sinusoidal density (FSD) following induction (+25%, P < 0.05) and maintenance at t = 95 min (+10.3%, P < 0.05), in ketamine and midazolam group decrease of FSD was observed after induction (−20.4%, P < 0.05; −10.1%, P < 0.05) and during maintenance at t = 65 min (−11.6%, P < 0.05; −11.4%, P < 0.05) when compared to baseline. Following induction with propofol functional capillary density (FCD) of ileal longitudinal muscle layer increased (+10.6%, P < 0.05) and returned to baseline values during maintenance. Ketamine and midazolam decreased FCD of longitudinal layer after induction (−24.6%, P < 0.05; −21.1%, P < 0.05) and remained decreased during maintenance at t = 95 min (−10.8%, P < 0.05; −15.5%, P < 0.05). In thiopental and control group, changes in microcirculatory parameters were not significant throughout the study. In conclusion, intravenous anesthetics affect the hepatosplanchnic microcirculation differentially, propofol has shown protective effect on the liver and intestinal microcirculation.
Posterior ocular involvement in Behçet's disease and thrombophilic mutations
Authors: Vayá Amparo , Miguel De la Fuente José , Suescun Marta , España Enrique , Ricart José M.
Published: December 2019

It is not well established whether there is an association among common inherited gene defects, Factor V (FV) Leiden, the prothrombin (PT) G20210A mutation, C677T methylene tetrahydrofolate reductase (MTHFR) and ocular Behçet's disease (BD). We aimed to evaluate the association of these mutations with posterior ocular involvement in 89 BD patients from eastern Spain (48 men and 41 women) of whom 23 had posterior ocular involvement and 66 did not. None of the 23 BD patients with posterior ocular involvement was a carrier of either FV Leiden or the PTG20210A mutation. Only 1 patient was a carrier of the 677TT MTHFR mutation, whereas 4 patients carried FV Leiden, 3 the PTG20210A mutation and 10 the 677TT MTHFR mutation in the group without posterior ocular involvement (p = 0.227, p = 0.556, p = 0.144), respectively. In our geographical area, the commonest thrombophilic mutations do not seem to be related with posterior ocular involvement in BD patients.
The hemorheological safety of pulsed electromagnetic fields in postmenopausal women with osteoporosis in southwest China: A randomized, placebo controlled clinical trial
Authors: Liu Huifang , Yang Lin , He Hongchen , Zhou Jun , Liu Ying , Wang Chunyan , Wu Yuanchao , He Chengqi
Published: December 2019

Apart from medications, pulsed electromagnetic fields (PEMFs) are used to treat osteoporosis nowadays. However studies on hemorheological safety of PEMFs were scarce. This randomized, placebo controlled clinical trial assessed whether PEMFs could lead to significant hemorheological changes. Fifty-five postmenopausal women were randomly assigned to receive placebo or PEMFs. Venous blood samples were collected at baseline and after treatment to measure 14 hemorheological determinants. Independent samples t-test, paired samples t-test and chi-squared tests were performed respectively. Relationships between variables were determined by Pearson correlation analysis. Multiple linear stepwise regression analysis was used to explore predictors of selected determinants. No significant differences existed between the placebo and PEMFs groups for any of the 14 hemorheological determinants (P > 0.05) or the percentage of patients with hemorheological determinant within reference range (P > 0.05). Hematocrit was found to be correlated with BMI (P = 0.007). The most significant predictor of blood reduced viscosity at low shear rate was blood viscosity at low shear rate. And blood reduced viscosity at high shear rate was the most important predictor of plasma viscosity. These results showed, compared with placebo, PEMFs treatment of postmenopausal osteoporosis was not associated with adverse changes in hemorheological determinants, which may contribute to venous thromboembolism.
Cocaine induces a reversible stomatocytosis of red blood cells and increases blood viscosity
Authors: Cagienard F. , Schulzki T. , Furlong P. , Reinhart W.H.
Published: December 2019

Severe side effects of cocaine consumption are vasoocclusive events such as myocardial infarction and stroke. We have hypothesized that cocaine could affect red blood cells (RBCs) and alter the rheological behaviour of blood. Heparinized blood from healthy volunteers was incubated with a final hematocrit of 45% with increasing cocaine concentrations: 0, 10, 100, 1000, and 10'000 μmol/L plasma. Time dependence of the shape change was tested in phosphate buffered saline containing cocaine. RBCs were fixed in 1% glutaraldehyde for morphological analysis. Blood viscosity was measured with a Couette Viscometer (Contraves LS 30) at 37°C and a shear rate of 69.5 s−1. RBC aggregation was assessed with a Myrenne aggregometer. Cocaine induced a dose-dependent stomatocytic shape transformation of RBCs, which was more pronounced in buffer than in plasma (plasma protein binding of the drug). Stomatocytosis occurs when a drug intercalates preferentially in the inner half of the membrane lipid bilayer. It was a time-dependent process with two components, an almost instant shape change occurring within 1 s, followed by a gradual further shape change during 10 min. Stomatocytosis was reversible by resuspension of the RBCs in cocaine-free buffer. This stomatocytic shape change increased whole blood viscosity at high shear rate from 5.69 ± 0.31 mPa.s to 6.39 ± 0.34 mPa.s for control and 10'000 μmol/L cocaine, respectively (p < 0.01). RBC aggregation was not affected by the shape change. These effects occurred at a cocaine concentration, which is several-fold above those measured in vivo. Therefore, it is unlikely that hemorheological factors are involved in vascular events after cocaine consumption.
Psoriasis and hemorheology. Influence of the metabolic syndrome
Authors: Vayá Amparo , Ricart Jose M. , Andino Belinda , Todoli Jose , Nuñez Cornelio , Calvo Javier , Bautista Daniel
Published: December 2019

Psoriasis is a systemic inflammatory disorder with increased cardiovascular risk which has been partly attributed to the increased prevalence of the metabolic syndrome (MS). However, the contribution of rheological alterations to cardiovascular risk has been scarcely investigated. In 91 psoriasis patients and in 101 healthy volunteers, we determined the rheological profile (fibrinogen, blood viscosity and erythrocyte aggregation), along with lipidic and inflammatory parameters. Patients showed statistically higher BMI, waist, triglycerides, insulin, c-reactive protein (CRP), neutrophils, lower HDL-cholesterol and a higher MS prevalence (p < 0.05). When subjects with MS were excluded from the study, patients with psoriasis still showed a worse inflammatory, lipidic and rheological profile in the above-mentioned variables compared with controls without MS (p < 0.05). The logistic regression analysis revealed that abdominal obesity and fibrinogen >384 mg/dL were independent predictors of psoriasis (OR 3.75 95% CI 1.77–7.94, p < 0.001; OR 2.95 95% CI 1.14–7.64, p = 0.025), respectively. Patients on biologics, showed less inflammation and a better rheological profile than those not on biological treatment. In conclusion, patients with psoriasis show an altered rheological profile, which may contribute to increased cardiovascular risk. Although the presence of MS worsens this profile, psoriasis per se shows rheological alterations due to both inflammation and altered metabolic parameters. Anti TNF-α treatment markedly improves the rheological profile by mostly decreasing inflammation.
Natural Large Degree Spectra
Authors: Diamondstone David , Greenberg Noam , Turetsky Daniel
Published: December 2019

We show that the collection of array non-recursive degrees, the collection of non-jump-traceable degrees, and the collection of degrees which compute a function not dominated by any ω-computably approximable function, are all degree spectra of countable structures.
On maximum conservative extensions
Authors: Towsner Henry
Published: December 2019

We investigate the set of Π12 sentences which are Π11 conservative over theories of second order arithmetic. We exhibit new elements of these sets and conclude that the sets are Π2 complete. Along the way, we show that, over the theory RCA0, induction for Σn formulas has essentially no consequences for Δn+1 formulas.
Developmental Conditions of Adaptive Self-Stabilization in Adolescence: An Exploratory Study
Authors: Greve Werner , Thomsen Tamara
Published: December 2019

In a cross-sectional study with 541 German students (mean age: 12.61 yrs) and (for a subsample of N = 350) one of their parents, developmental conditions for a particular resource of self-regulation (“Flexibility of Goal Adjustment”; Brandtstädter & Renner, 1990) are investigated. Theoretical arguments and empirical results from related fields suggested in particular two sets of variables as possible predictors of adolescents' adaptive competencies. Individual aspects (students' cognitive capacities and earlier developmental stimulations) as well as external conditions (parental coping competences and parent-youth-coorientation) were assessed and included into a path model. Results suggest that both the parental variables and particular cognitive resources contribute directly to adolescents' adaptive resources, whereas earlier developmental stimulations influenced adolescents' adaptive resources in an indirect way. Suggestions for further studies were discussed with respect both to theoretical and methodological aspects.
Motivational Selectivity Prospectively Predicts Couples' Realization of Their Goal to Have a Child
Authors: Rauers Antje , Böhnke Anja , Riediger Michaela
Published: December 2019

Developmental theories have emphasized that motivational selectivity – focusing on a few goals instead of “wanting it all” – regulates development in individuals, dyads, or groups. We provide first evidence that this motivational strategy predicts an objective, goal-related developmental outcome years later. We followed up on initially childless couples in which both partners had reported the goal of starting a family within the next three and a half years. At baseline, partners reported on their general behavioral tendency to prioritize goals of particular importance in their partnership (i.e., their motivational selectivity). Three and a half years later, 50% of the couples had realized the goal to have a child. The higher the couples' initial motivational-selectivity scores had been, the more likely they were to have indeed started a family, controlling for other potential predictors of child-bearing. These findings suggest that motivational selectivity meaningfully characterizes social entities like couples, and regulates their development.
The effect of virtual reality on visual vertigo symptoms in patients with peripheral vestibular dysfunction: A pilot study
Authors: Pavlou M. , Kanegaonkar R.G. , Swapp D. , Bamiou D.E. , Slater M. , Luxon L.M.
Published: December 2019

Individuals with vestibular dysfunction may experience visual vertigo (VV), in which symptoms are provoked or exacerbated by excessive or disorientating visual stimuli (e.g. supermarkets). VV can significantly improve when customized vestibular rehabilitation exercises are combined with exposure to optokinetic stimuli. Virtual reality (VR), which immerses patients in realistic, visually challenging environments, has also been suggested as an adjunct to VR to improve VV symptoms. This pilot study compared the responses of sixteen patients with unilateral peripheral vestibular disorder randomly allocated to a VR regime incorporating exposure to a static (Group S) or dynamic (Group D) VR environment. Participants practiced vestibular exercises, twice weekly for four weeks, inside a static (Group S) or dynamic (Group D) virtual crowded square environment, presented in an immersive projection theatre (IPT), and received a vestibular exercise program to practice on days not attending clinic. A third Group D1 completed both the static and dynamic VR training. Treatment response was assessed with the Dynamic Gait Index and questionnaires concerning symptom triggers and psychological state. At final assessment, significant between-group differences were noted between Groups D (p=0.001) and D1 (p=0.03) compared to Group S for VV symptoms with the former two showing a significant 59.2% and 25.8% improvement respectively compared to 1.6% for the latter. Depression scores improved only for Group S (p=0.01) while a trend towards significance was noted for Group D regarding anxiety scores (p=0.07). Conclusion: Exposure to dynamic VR environments should be considered as a useful adjunct to vestibular rehabilitation programs for patients with peripheral vestibular disorders and VV symptoms.