bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of vessel age and early diagnose of atherosclerosis in progeria syndrome by using echo-tracking
Authors: Várady E. , Feher E. , Levai A. , Battyany I.
Published: December 2019

The stiffness of the arteries normally increases with age. Radiofrequency echo-tracking is a non-invasive ultrasound method which is able to detect the stiffness of the arteries, represented by the β stiffness index. The estimation of biological age of vessels is possible on the basis of the normal age-group specific β stiffness values. The β stiffness index becomes higher in early stages of atherosclerosis as well, before any visible morphological changes. Hutchinson–Gilford progeria syndrome (HGPS) is rare genetic disorder resulting in accelerated aging including appearance of progressive atherosclerosis at an early age which determines the quality and term of life of these patients. Determination of vascular age and early diagnosis of atherosclerosis seems crucial. According to our knowledge, the estimation of vascular age detected with radiofrequency echo-tracking in HGPS patients, in contrast to the normal age-specific β stiffness values, has not been published yet.
Red blood cell deformability and aggregation, cell adhesion molecules, oxidative stress and nitric oxide markers after a short term, submaximal, exercise in sickle cell trait carriers
Authors: Tripette Julien , Connes Philippe , Beltan Éric , Chalabi Tawfik , Marlin Laurent , Chout Roger , Baskurt Oguz K , Hue Olivier , Hardy-Dessources Marie-Dominique
Published: December 2019

The present study investigated the hemorheological and endothelial alterations in sickle cell trait (SCT) carriers in response to a submaximal exercise. Eleven SCT carriers and 11 subjects with normal hemoglobin performed submaximal exercise for 15 min. Blood was sampled at rest, at the end of exercise, and at 2 and 24 h of recovery. Hemorheological alterations observed in the SCT group were as follows: 1) lower RBC deformability at high shear stress at all time-points, with no relation to oxidative stress, 2) higher disaggregation threshold at all time-points, suggesting RBC hyper-aggregation, and 3) higher blood viscosity at the end of exercise and during recovery. Exercise had a specific influence on the levels of the soluble cell adhesion molecules P and L-selectin in the SCT carriers, with higher P-selectin levels at all time-points and a greater increase in L-selectin levels during recovery. SCT carriers had slightly decreased nitrite levels at 24h of recovery, which might be clinically insignificant. In conclusion, the hemorheological alterations in association with lower NO production found in the SCT carriers are probably not sufficient to explain the medical complications sometimes reported in SCT carriers after exercise.
Inhibition of glycogen synthase kinase-3β prevents activation of focal adhesion kinase after ischemia/reperfusion of the rat lung
Authors: Waldow Thomas , Witt Wolfgang , Matschke Klaus
Published: December 2019

Recent studies on the mechanisms of ischemic preconditioning in myocardial tissue have presented convincing evidence that multiple protective pathways converge on inhibition of glycogen synthase kinase-3β (GSK-3β). To directly address the role of GSK-3β in ischemia and reperfusion (I/R) of the lung, a rat model of left lung in situ ischemia was used. The specific non-competitive inhibitor of GSK-3β, TDZD-8, was injected (3 mg/kg, vehicle in controls) 5 min before the left lung hilum was occluded for 60 min. Animals in the ischemia group underwent the same treatment, but without administration of TDZD-8. Lung functional and biochemical parameters were determined at time points 15 min and 60 min reperfusion. Treatment with TDZD-8 improved gas exchange (arterial pO2), but I/R-induced inflammation (plasma interleukin-6, leukocyte invasion) was not affected. The I/R cycle induced a rapid (15 min reperfusion) increase of protein tyrosine phosphorylation, including the activating phosphorylation of focal adhesion kinase at Tyr397, Tyr407, Tyr577, and Tyr861, and the non-receptor kinase Src at Tyr416. The phosphorylation was blocked by the GSK inhibitor. This effect may be related to the reduced plasma level of the strong effector of focal adhesion kinase, transforming growth factor-β1, in the TDZD group. The underlying mechanisms are elusive, but they deserve further investigation, especially in relation to the early increase of lung permeability in this rat model of I/R injury. In conclusion, the results suggest that inhibition of GSK-3β improves rat lung function during an I/R cycle, but only during the early reperfusion phase.
Influence of VEGF stimulated human macrophages on the proliferation of dermal microvascular endothelial cells: Coculture experiments
Authors: Hiebl B. , Bog S. , Mrowietz C. , Jünger M. , Jung F. , Lendlein A. , Franke R.-P.
Published: December 2019

Monocytes/macrophages are known to exhibit pro-angiogenic activities after VEGF stimulation. Recently, it was shown that VEGF stimulated macrophages can support growth of microvascular endothelial cells from the lung when both cell types were cocultured using a cell ratio of 1:1. However, endothelial cells can have different phenotypic characteristics and metabolism depending on the originating vascular bed and tissues, and only few data have been published regarding the regiospecific sensitivity of microvascular endothelial cells for angiogenic stimuli. Reports about differences in the microvascular bed of the lung and the skin motivated to investigate angiogenic effects of VEGF stimulated macrophages (mΦa) on the doubling time and the cell growth behaviour of skin derived microvascular endothelial cells (HMVEC/S). During the study period of 60 days, mΦa supported growth and proliferation of the HMVEC/S, when mΦa and HMVEC/S were cocultured at a ratio of 0.5:1. However, these effects were not seen in a 1:1 coculture. This result indicates that there is a positive correlation between the pro-angiogenic effects of mΦa and the number of endothelial cells in the direct neighbourhood of the mΦa and also suggests a different sensitivity of microvascular endothelial cells to angiogenic stimuli depending on the tissue from which they were isolated.
Age-related carbonyl stress and erythrocyte membrane protein carbonylation
Authors: Li Guolin , Liu Li , Hu Hui , Zhao Qiong , Xie Fuxia , Chen Keke , Liu Shenglin , Chen Yaqin , Shi Wang , Yin Dazhong
Published: December 2019

Reactive carbonyl species (RCS) have been widely used as indicators of oxidative stress. However, the associations of carbonyl stress with aging process and biochemical alteration of erythrocyte are still poorly understood. Fresh blood samples in vacutainer tubes containing sodium heparinate were obtained from 874 volunteers who were divided into young, adult and old groups based on their age. Plasma RCS and thiols concentrations between different age groups and erythrocyte membrane protein carbonylation in the adult group were detected within 24h of the blood sampling. Results showed that the plasma thiols concentration decreased gradually during aging process, and the p-values between all three groups are less than 0.05. The plasma RCS concentration in different age groups showed a nonlinear association with age. The levels in the young group were slightly higher than the adult group (not significant) and lower than the old group (p < 0.01). The protein carbonylation of erythrocyte membrane was positively correlated with plasma RCS concentration (p < 0.01), but not plasma thiols concentration. We conclude that higher levels of RCS, not lower levels of thiols, in plasma are a direct risk factor for the protein carbonylation of erythrocyte membrane. Owing to the decrease of thiols levels and increase of RCS levels during aging process, a shift from RCS-related redox allostasis to carbonyl stress would contribute to age-related biological dysfunction and even aging process.
Microcirculatory effects of fluid therapy and dopamine, associated or not to fluid therapy, in endotoxemic hamsters
Authors: Santos Ana Olimpia M.T. , Furtado Eliane S. , Villela Nivaldo R. , Bouskela Eliete
Published: December 2019

Classically septic shock treatment takes into consideration only systemic parameters but failure in retaining arteriolar blood flow and functional capillary density (FCD) during sepsis worsens the outcome. Thus, we have investigated the effects of vigorous volume resuscitation (VR), two doses of dopamine and their combination upon the microcirculation during endotoxemia to evaluate if improvement on FCD and arteriolar blood flow would increase survival time. Sixty-seven adult male hamsters were studied using the window chamber model. Animals were randomized 1 h after the intravenous injection of 1 mg/kg of E. coli lipopolysaccharide (LPS) in LPS, no treatment; LPS/dopamine 3.0 μg/kg/min; LPS/dopamine 7.5 μg/kg/min; LPS/VR 20 ml/kg in 30 min followed by 20 ml/kg/h of saline; LPS/VR/Dopa 3.0, 20 ml/kg in 30 min followed by 20 ml/kg/h of saline associated to dopamine 3.0 μg/kg/min; LPS/VR/Dopa 7.5 (n = 6), 20 ml/kg in 30 min followed by 20 ml/kg/h of saline associated to dopamine 7.5 μg/kg/min and compared them to a Control group, no LPS. When present, treatment lasted 5 h. VR improved FCD and arteriolar blood flow score while dopamine did not. In conclusion, (1) improvement of FCD and arteriolar blood flow improved survival time; (2) VR recovered FCD and arteriolar blood flow and (3) in combination to VR, both dopamine doses reduced tissue perfusion (its low dose yielded the worst result).
Hyperhomocysteinemia, obesity and cryptogenic stroke
Authors: Vayá A. , Ejarque I. , Tembl J. , Corella D. , Laiz B.
Published: December 2019

Background: The pathogenic role of hyperhomocysteinemia in cryptogenic stroke is not well established. We aimed to determine homocysteine levels in patients with cryptogenic stroke considering the possible variables that may act as confounders and analyze the influence of obesity on this association. Patients and methods: We conducted a case-control study in 123 patients with cryptogenic stroke aged 42 ± 12 years and in 153 control subjects aged 42 ± 13 years. Serum homocysteine was determined by fluorescence polarization immunoassay. Results: Patients showed statistically higher levels of homocysteine, creatinine and higher BMI than controls (p = 0.045, p = 0.014, p = 0.013), respectively. After multivariate adjustment the differences in homocysteine levels disappeared (p = 0.774). When subjects were classified according to the presence or absence of obesity, the differences in the prevalence of hyperhomocysteinemia (homocysteine >15 μM) were highly significant, being higher in patients than in controls (p = 0.009). Likewise, mean values of homocysteine in obese were higher in cases than in controls (16.9 ± 9.5 μM vs. 10.12 ± 2.5 μM; p = 0.020), remaining significant after adjusting for the above mentioned confounders. Conclusion: Although in general, hyperhomocysteinemia does not seem to constitute an independent risk factor for cryptogenic stroke, it significantly increases the risk in obese subjects; therefore it is convenient to decrease its levels in this sub-group to minimize the risk.
The effect of aging on blood and plasma viscosity. An 11.6 years follow-up study
Authors: Carallo C. , Irace C. , De Franceschi M.S. , Coppoletta F. , Tiriolo R. , Scicchitano C. , Scavelli F. , Gnasso A.
Published: December 2019

Objective: Alterations of blood and plasma viscosity can promote atherosclerosis. The relationship between viscosity and aging is still controversial. The present study evaluated the influence of aging on blood and plasma viscosity in a group of subjects followed for 11.6 years. Methods: Forty-five subjects have been evaluated twice 11.6 years apart for hemorheological parameters and coronary heart disease (CHD) risk factors. Plasma viscosity and blood viscosity have been measured with a cone-plate viscometer. Tk has been calculated as index of red blood cell rigidity. CHD risk factors, i.e. obesity, hypertension, hyperlipidemia and diabetes, have been evaluated by routine methods. Results: Hematocrit and plasma viscosity did not change during the study, whereas blood viscosity (shear rate 225/sec: 4.46 ± 0.49 vs. 4.81 ± 0.54 cP, p < 0.0001; shear rate 45/sec: 6.19 ± 0.67 vs. 6.65 ± 0.79 cP, p < 0.0001) and Tk (0.80 ± 0.05 vs. 0.83 ± 0.06, p < 0.005) significantly increased. The percent variation in blood viscosity was not associated with the percent variation in any of the CHD risk factors. Furthermore, the increase in blood viscosity was similar in males and females and in subjects with CHD risk profile worsening or not. Conclusion: The present findings demonstrate that blood viscosity increases with age. This increase seems independent of classical CHD risk factors and is disjoined from haematocrit and plasma viscosity, suggesting a possible direct effect of aging on red blood cells.
Wavelet analysis of skin blood flow in dermatosurgery using primary closure with tension
Authors: Häfner Hans-Martin , Bräuer Kurt , Kneilling Manfred , Moehrle Matthias , Breuninger Helmut
Published: December 2019

Primary closure in dermatologic surgery is state of the art in small lesions at the head, but also in larger lesions at the trunk or the extremities. Microcirculatory effects on the skin blood flow near to the wound edges affected by primary closure. Forty three patients were investigated. Before and after surgery, skin blood flow was measured using Laser Doppler Fluxmetry (LDF). During primary closure, tension in the suture was measured and the tension on the wound edges was calculated. Times series were analyzed using continuous wavelet analyses, before, after 2 h and 24 h after surgery. After three months, the cosmetic results were requested. Median horizontal diameter was 22 mm (quartiles 20/48 mm), median vertical diameter was 44 mm (quartiles 26/60 mm). Mean string force was 12.0 SD 10.2 N. During the whole course of investigation, we found no change of microcirculatory parameters such as mean LDF or any scaling level following wavelet analysis caused by primary closure. Average of the cosmetic result was 1.8. It is a relative small number of patients and the defects are located in different areas. Skin blood flow and the microcirculatory pattern is not affected in the area by the tension on wound edges and provides therefore a fast healing process without any vegetatively induced complications even if the string force is high. In dermatosurgery, wounds can be closed directly without changing the microcirculatory pattern in the direct area of the wound margins.
Reviewing data reduction methods for ektacytometry
Authors: Kenyeres P. , Rabai M. , Toth A. , Kesmarky G. , Marton Zs. , Alexy T. , Toth K.
Published: December 2019

Ektacytometry quantifies erythrocyte deformability by measuring the elongation of suspended red blood cells subjected to a range of shear stresses. Raw shear stress-elongation index plots are difficult to interpret and thus data reduction methods characterizing the relationship using few parameters without loss of information and good reproducibility are essential, especially for the clinician. Two such curve fitting formulas, used widely in the literature for this purpose, are reviewed herein. The Lineweaver-Burke method overestimates maximal deformability if shear stresses below 1 Pa are applied. A modified version of the formula estimates maximal deformation more accurately but gives little weight to data at low shear stresses. Neither method is accurate if negative elongation indices are present (artifact phenomenon when measurement is performed from high to low shear stresses). The Streekstra-Bronkhorst method provides efficient data reduction though the theoretical background of the formula is incorrect. The parameters have expressive meaning; however, both maximal and minimal deformations are slightly underestimated. Moreover, parameters are biased according to the range of measured shear stresses.
In vitro effects of polyethylene glycol in University of Wisconsin preservation solution on human red blood cell aggregation and hemorheology
Authors: Zhao Wen-Yu , Xiong Hai-Yun , Yuan Qing , Zeng Li , Wang Li-Ming , Zhu You-Hua
Published: December 2019

Addition of hydroxyethyl starch (HES) to UW (University of Wisconsin) solution increases viscosity of the solution and red blood cell (RBC) aggregation. Recently, it was suggested that HES could be replaced by a new colloid, polyethylene glycol (PEG), in UW solution. The aim of this study was to see whether and how PEG affected RBC aggregation, and whether RBC aggregation parameters had any correlation with the molecular weight and concentration of PEG. After giving informed consent and signing consent documents, 12 healthy volunteers were enrolled in the study. Blood samples obtained from these volunteers were mixed with the test solutions with blood/solutions ratios of 5:1 and 1:1. Human RBC aggregation was investigated with an automatic hemorheological analyzer. Blood viscosity was measured with a cone-plate viscometer. Morphological characters of RBC aggregates were evaluated by light microscopy. It was found that viscosity was not affected by the Colloid-free UW solution. PEG20kDa (1 and 10 g/L) and PEG35kDa (1 g/L) had little effect on RBC aggregation, while PEG20kDa (30 g/L) and PEG35kDa (10 and 30 g/L) had a significant hyperaggregating effect on RBC. In conclusion, PEGs had a potential hyperaggregating effect on human RBC. This effect is correlated with PEG molecular weight and concentration. The use of large molecular weight and high concentration PEG in UW solution accounts for extended and accelerated aggregation of erythrocytes. The use of low concentration PEG35kDa (1 g/L) would be the optimal choice.
Effects of posture and ergometer-specific exercise modality on plasma viscosity and plasma fibrinogen: The role of plasma volume changes
Authors: El-Sayed Mahmoud S. , Ali Nagia , Omar Ayad Abuelgasem
Published: December 2019

The aim of the present study was ascertain the effects posture and exercise modality on the main determinants of blood rheology. Thirteen subjects performed two exercise trials, in random order, at approximately 70% VO2 max for 45-min. One trial was performed on a motorized treadmill at an intensity corresponding to 70% VO2 max, while the other was performed on a stationary pike at an intensity corresponding to 70% VO2 max. In the cycling trial subjects stood for 30-min, followed by sitting for 30-min then cycled for 30-min at 70% VO2 max. In the treadmill trial, subjects sat for 30-min followed by standing for 30-min then ran on the treadmill for 30-min at 70% VO2 max. Variations of body postures prior to exercise were associated with opposite changes in plasma volume, plasma viscosity and plasma fibrinogen. When post exercise raw data were not adjusted for plasma volume changes, a significant increase (p < 0.05) in plasma viscosity and plasma fibrinogen was found with no difference between the cycling and running trials. However, the increase in plasma viscosity and fibrinogen were no longer apparent when the raw data post exercises were adjusted for plasma volume changes. Changing body posture from standing to sitting and vice versa were associated with opposite changes in plasma volume and mirrored the changes in plasma viscosity and fibrinogen. In addition, ergometer-specific vigorous exercises at the same relative intensity, irrespective of its modality, transiently increased plasma viscosity and plasma fibrinogen mainly due to exercise-associated haemoconcentration.
Metabolic alterations in morbid obesity. Influence on the haemorheological profile
Authors: Vayá Amparo , Hernández-Mijares Antonio , Suescun Marta , Solá Eva , Cámara Rosa , Romagnoli Marco , Bautista Daniel , Laiz Begoña
Published: December 2019

There are few studies on haemorheological disturbances in morbidly obese patients. The role played by the metabolic syndrome on the rheological profile of morbidly obese subjects has not yet been established, and it is not clear whether morbidly obese, but “metabolically healthy”, show rheological alterations. We aimed to determine the whole rheological profile in 136 morbidly obese patients and 136 normo-weight volunteers, along with plasma lipids, inflammatory and insulin resistance parameters. Patients had statistically higher glucose, triglycerides, HbA1c, leptin, insulin, HOMA, CRP, leucocytes, fibrinogen, plasma viscosity (p < 0.001, respectively), erythrocyte aggregation at 3 s−1 (p = 0.011) and lower erythrocyte elongation index 60 Pa (p = 0.015). In the multivariate regression analysis, the anthropometric, lipidic, insulin resistance and inflammatory parameters predicted haemorheological variables (p < 0.001). No differences were observed for the rheological parameters when morbidly obese subjects with (n = 75) and without (n = 61) the metabolic syndrome were compared (p > 0.05), indicating that the altered rheological profile not only related to the metabolic syndrome, but to obesity itself. When further patients were classified as “metabolically healthy” obese (n = 23) and “metabolically unhealthy” obese (n = 113), the latter presented higher insulin resistance (insulin p < 0.01, HOMA p < 0.05, glucose p < 0.001, triglycerides p < 0.05 and HbA1c p < 0.01) than the former, but no differences in the rheological parameters (p > 0.05) were observed. When “metabolically healthy” obese (n = 23) were compared with “metabolically healthy” controls (n = 81), the former still showed higher HOMA (p < 0.001), triglycerides (p < 0.05), CRP (p < 0.001) and HbA1c (p < 0.05), higher fibrinogen (p < 0.001), plasma viscosity (p < 0.001), erythrocyte aggregation at 3 s−1 (p < 0.05), but a lower erythrocyte elongation index 60 Pa (p < 0.05). Morbidly obese subjects present a more pronounced altered rheological profile in those with metabolic alterations, although the “metabolically healthy” obese also displayed rheological alterations if compared with “metabolically healthy” non-obese controls. These rheological alterations relate to both insulin resistance and inflammation.
Preliminary findings in the heart rate variability and haemorheology response to varied frequency and duration of walking in women 65–74 yr with type 2 diabetes
Authors: Simmonds Michael J. , Minahan Clare L. , Serre Kevin R. , Gass Gregory C. , Marshall-Gradisnik Sonya M. , Haseler Luke J. , Sabapathy Surendran
Published: December 2019

Heart rate variability (HRV) and haemorheology adaptations to 12 wk of varied-dose treadmill walking were investigated in women aged 65–74 yr with type 2 diabetes. Subjects were randomly allocated into two groups where exercise frequency and session duration were manipulated (Group 1 : 2 × 60 min·wk−1 or Group 2 : 4 × 30 min·wk−1), but intensity and accumulated weekly duration of exercise were consistent between groups (100% gas-exchange threshold; 120 min·wk−1). Twelve weeks of exercise training significantly improved peak oxygen uptake, time to exhaustion, and gas-exchange threshold (p < 0.05), independent of exercise group. Exercise training did not significantly change glycaemic control or body mass. Red blood cell (RBC) aggregation and RBC deformability significantly decreased (p < 0.05) for both groups. No change in HRV was observed for Group 1, whereas several key indicators of HRV were significantly improved in Group 2 (p < 0.05). The present study was the first to report decreased RBC aggregation following an exercise-only intervention and that exercise training improved RBC aggregation without a concomitant improvement in glycaemic control. The accumulated weekly exercise duration may be the most important training component for the prescription of exercise in older women with type 2 diabetes.
Effects of cigarette smoking on morphology and aggregation of erythrocytes
Authors: Yuvraj V. , Indumathi J. , Singh M.
Published: December 2019

Erythrocyte deformability and aggregation are important parameters related to blood flow in cardiovascular system. These are generally determined by various techniques. The present work is an attempt to implement a computerized procedure based on microscopic images of erythrocytes, obtained from cigarette smokers, to calculate these and related parameters. The subjects who have been smoking for more than ten years (Group 2) are selected and the calculated parameters are compared with that of non-smoking subjects (Group 1). The shape parameters area, perimeter and form factor of erythrocytes show significant change in Group 2 compared to that of Group 1. The erythrocyte aggregation, as measured by area occupied by aggregates, shows significant reduction in smokers, attributed to enhanced cell-cell interaction in Group 2. The ratio of crenated to normal erythrocytes increases immediately after smoking but reverts back to initial level after a gap of more than one hour, which is attributed to the change in metabolic activity of erythrocytes.
Association of hematological parameters with insulin resistance, insulin sensitivity, and asymptomatic cerebrovascular damage: The J-SHIP and Toon Health Study
Authors: Tabara Yasuharu , Igase Michiya , Saito Isao , Nishida Wataru , Kohara Katsuhiko , Sakurai Susumu , Kawamura Ryoichi , Okada Yoko , Hitsumoto Shinichi , Onuma Hiroshi , Nagai Tokihisa , Takata Yasunori , Uetani Eri , Takita Rie , Kido Tomoko , Ochi Namiko , Osawa Haruhiko , Tanigawa Takeshi , Miki Tetsuro
Published: December 2019

BACKGROUND: Elevated hematocrit levels have been suggested to be an independent determinant of insulin resistance and type 2 diabetes. To clarify the diagnostic significance of hematocrit level, we investigated the association with hemodynamic profiles, insulin resistance and insulin sensitivity, arterial properties, and asymptomatic cerebrovascular damage in a general Japanese population. METHODS: This study included 1,978 participants from two independent cohorts. Insulin sensitivity was assessed by the oral 75 g glucose tolerance test. Carotid ultrasonography was performed to evaluate atherosclerosis and wall shear stress. Periventricular hyperintensity and lacunar infarction were assessed by brain magnetic resonance imaging. RESULTS: Hematocrit quartile showed a stepwise association with insulin sensitivity (Q1: 2.2 ± 0.7, Q2: 2.0 ± 0.7, Q3: 1.9 ± 0.7, Q4: 1.8 ± 0.6, p < 0.001) and insulin resistance (1.0 ± 0.6, 1.2 ± 0.7, 1.3 ± 0.8, 1.5 ± 1.0, p < 0.001). Multiple linear regression analysis adjusted for possible covariates identified hematocrit as an independent determinant of insulin sensitivity (β = −0.074, p = 0.019) and insulin resistance (β = 0.115, p < 0.001). However, this association was lost after further adjustment for visceral fat area and plasma alanine aminotransferase level. Further, no significant association was observed between hematocrit and carotid intima-media thickness (p = 0.306) where as wall shear stress was inversely associated with the carotid atherosclerosis (r = −0.250, p < 0.001). In contrast, a low hematocrit level was independently associated with periventricular hyperintensity (odds ratio 0.87 (95% CI 0.80–0.95), p = 0.001). CONCLUSION: Hematocrit was positively associated with insulin resistance and insulin sensitivity. This association was epiphenomenon of visceral and hepatic adiposity. Conversely, low hematocrit was a significant risk factor for periventricular hyperintensity independent of insulin resistance.
Association between hemorheological alteration and clinical diagnosis of metabolic syndrome among patients qualified for bariatric surgery
Authors: Wiewiora Maciej , Slowinska-Lozynska Ludmila , Glück Marek , Piecuch Jerzy , Sosada Krystyn , Monkos Karol
Published: December 2019

This study presents the association between metabolic syndrome and hemorheological parameters among obese patients qualified for bariatric surgery. We studied 73 morbidly obese patients who were qualified for bariatric surgery. Blood and plasma viscosity measurements were performed using a cone-plate viscometer (Brookfield DV-II). RBC aggregation was measured using the Laser-assisted Optical Rotational Cell Analyser (LORCA). The following parameters for the aggregation process were estimated: aggregation index (AI), amplitude (AMP), aggregation half-time (t1/2), threshold shear rate (γthr), the fast (Tfast) and the slow (Tslow) component. Metabolic syndrome was defined according to the Adult Treatment Panel III and International Diabetes Federation criteria. The obese presented differences in all rheological properties compared to control, regardless of clinical diagnosis of metabolic syndrome, except that whole blood viscosity was higher only in the obese metabolic syndrome group. No differences among the obese with and without metabolic syndrome were observed except in hematocrit. Whole blood viscosity and corrected blood viscosity correlated positively with WHR and BMI. AI, γthr, Tslow correlated positively with BMI, WHR, total cholesterol level and low-density lipoproteins. Negative correlation presented t1/2 with BMI, WHR, fibrinogen, total cholesterol level and low-density lipoproteins. The study showed that morbid obesity is associated with hemorheological disturbances independently of clinical diagnosis of metabolic syndrome.
Confluence in Data Reduction: Bridging Graph Transformation and Kernelization
Authors: Ehrig Hartmut , Ermel Claudia , Hüffner Falk , Niedermeier Rolf , Runge Olga
Published: December 2019

Kernelization is a core tool of parameterized algorithmics for coping with computationally intractable problems. A kernelization reduces in polynomial time an input instance to an equivalent instance whose size is bounded by a function only depending on some problem-specific parameter k; this new instance is called problem kernel. Typically, problem kernels are achieved by performing efficient data reduction rules. So far, there was little systematic study in the literature concerning the mutual interaction of data reduction rules, in particular whether data reduction rules for a specific problem always lead to the same reduced instance, no matter in which order the rules are applied. This corresponds to the concept of confluence from the theory of rewriting systems. We argue that it is valuable to study whether a kernelization is confluent, using the NP-hard graph problems (EDGE) CLIQUE COVER and PARTIAL CLIQUE COVER as running examples. We apply the concept of critical pair analysis from graph transformation theory, supported by the AGG software tool. These results support the main goal of our work, namely, to establish a fruitful link between (parameterized) algorithmics and graph transformation theory, two so far unrelated fields.
Hyperprojective hierarchy of qcb0-spaces
Authors: Schröder Matthias , Selivanov Victor
Published: December 2019

We extend the recently introduced Luzin hierarchy of qcb0-spaces to all countable ordinals, obtaining in this way the hyperprojective hierarchy of qcb0-spaces. We generalize all main results for the former hierarchy to this larger hierarchy. In particular, we extend the Kleene–Kreisel continuous functionals of finite types to the continuous functionals of countable types and relate them to the new hierarchy. We show that the category of hyperprojective qcb0-spaces has much better closure properties than the category of projective qcb0-spaces. As a result, there are natural examples of spaces that are hyperprojective but not projective.
Investigating Valence and Autonomy in Children's Relationships with Imaginary Companions
Authors: McInnis Melissa A. , Pierucci Jillian M. , Gilpin Ansley Tullos
Published: December 2019

Little research has explored valence and autonomy in children's imaginary relationships. In the present study, a new interview (modeled after an existing measure for real relationships) was designed to elicit descriptions of both positive and negative interactions with imaginary companions and to provide a measure of relationship valence and autonomy. Children (n = 107) aged 3 to 8 were interviewed about their relationships with real or imaginary friends. Results indicated that (1) the valence of imaginary relationships falls along a continuum, (2) children sometimes view their imaginary companions as autonomous and in control of the imaginary relationship (especially when this relationship is not positively valenced), and (3) young children and those in less positive relationships (real or imaginary) were more likely to report that they could make their friend be nice to them.
Long-term Consequences of Victimization by Peers: A Follow-up from Adolescence to Young Adulthood
Authors: Isaacs Jenny , Hodges Ernest V.E. , Salmivalli Christina
Published: December 2019

Long-term effects of victimization were investigated in 177 girls and boys that were followed from adolescence (ages 14-15) to young adulthood (ages 22-23). Victimization in adolescence was associated with increases in depression and decreases in self-esteem as well as negative views of others in young adulthood, but only when adolescents lacked a supportive family environment. Results are discussed in terms of possible mechanisms responsible for the critical role that family support plays in altering maladjustment consequences of victimization by peers.
Use of the Vestibular Disorders Activities of Daily Living Scale to describe functional limitations in patients with vestibular disorders1
Authors: Cohen Helen S.
Published: December 2019

The Vestibular Disorders Activities of Daily Living Scale (VADL) is one of several self-rated scales in the literature that may be useful for determining level of functional limitation or disability in people with vestibular disorders. The VADL was designed by an occupational therapist for use in treatment planning during vestibular rehabilitation. Unlike many other scales the VADL is specifically focused on essential functional skills and important mobility and instrumental skills. This paper reviews the findings about the VADL, including the original research about its development and more recent papers using it. The scale is most useful for assessing the patient's perception about independence in personal, self care and basic mobility skills. It provides an outline for discussing instrumental activities of daily living.
Ondansetron reduces lasting vestibular deficits in a model of severe peripheral excitotoxic injury
Authors: Dyhrfjeld-Johnsen Jonas , Gaboyard-Niay Sophie , Broussy Audrey , Saleur Aurélie , Brugeaud Aurore , Chabbert Christian
Published: December 2019

Vestibular neuritis is a neuroinflammatory, peripheral vestibular pathology leading to chronic deficits and long-term disability. While current corticosteroid-based therapy does not appear to positively influence the long term outcome for the patient, a recent clinical pilot study suggested a functional vestibuloprotective effect of the anti-emetic ondansetron in the treatment of vestibular neuritis. We here demonstrate that systemic post-insult administration of ondansetron in a novel rat model of severe excitotoxic vestibular insult reproduces the clinically demonstrated functional benefits. This ondansetron-conferred reduction of functional deficits stems from the protection of synapses between sensory hair cells and primary neurons from excitotoxically induced lesion.
Discussion of the dizziness handicap inventory
Authors: Mutlu Basak , Serbetcioglu Bulent
Published: December 2019

Purpose: A review of the Dizziness Handicap Inventory (DHI). Number of studies: Seventy-four studies. Materials/methods: Articles published between January 1990 and May 2012 were identified by searches in PubMed electronic database. Of the 227 articles meeting the inclusion criteria 74 were reviewed. These articles are discussed under nine topics; Reliability, validity and internal consistency of the original version of DHI, relationship between vestibular/balance tests and DHI, association between DHI and the other scales related to balance impairments, exploratory factor analysis of the DHI, screening version of DHI, translations of DHI into other languages, the role of DHI to assess the success of the treatment of balance disorder, DHI results in various vestibular disorders, general characteristics of DHI in patients with balance impairment. Conclusions: Self reported measures represent unique pieces of the information important for the management of dizzy patients. DHI is the most widely used self reported measurement of patients with dizziness. It has been translated into fourteen languages, so it is widely accepted.
The effect of rise/fall time of 500 Hz short tone bursts on cervical vestibular evoked myogenic potential
Authors: Singh Niraj Kumar , Apeksha Kumari
Published: December 2019

Background: Cervical vestibular evoked myogenic potential (cVEMP) is a biphasic potential recorded from the Sternocleidomastoid muscle in response to loud acoustic stimulation and assesses the intactness of the Sacculocolic pathway. The literature on clinical utility of cVEMP has been growing rapidly, though not without inconsistencies despite involving alike population. A close scrutiny of the methods across such studies revealed an inconsistent use of stimulus parameters; especially rise/fall times (RFTs). However the effect of RFTs on cVEMP has been largely unexplored. Objective: The study aimed at exploring the effect of varying RFTs on cVEMP and obtaining optimum RFT to enable reliable recording of cVEMPs. Methods: The cVEMPs were recorded from both ears of 30 healthy individuals with normal audio-vestibular system using 500 Hz short tone-bursts (STBs) at 95 dB nHL and varying the RFTs from 1 to 8 ms at all integer values. Results: There was significant prolongation of latencies with increasing RFTs (p< 0.05). The largest amplitudes were obtained for 2 to 3 ms RFTs, though significantly smaller amplitude was obtained only for 8 ms RFT (p< 0.05), thereby rendering 8 ms RFT unfit for cVEMP recording. The 1 ms RFT produced smallest variability across individuals and would also result in lesser duration of exposure to loud sound. Conclusions: The RFT of 1 ms of 500 Hz STBs are optimum for recording cVEMPs. This is owing to large amplitudes and least variability demonstrated for this RFT.
Combined peripheral and central vestibulopathy
Authors: Choi Seo-Young , Kee Hyun-Ju , Park Jae-Han , Kim Hyo-Jung , Kim Ji-Soo
Published: December 2019

Diagnosis of central vestibulopathy remains a challenge when it is associated with peripheral vestibular dysfunction because neurotological findings from peripheral vestibulopathy may overshadow those from central vestibular involvements. To define the characteristics of disorders involving both peripheral and central vestibular structures, we classified the combined vestibulopathies into four types according to their vestibular manifestations, and describe a typical case in each subtype. Infarction involving the territory of anterior inferior cerebellar artery is the most common cause of acute unilateral cases, whereas tumors involving the cerebellopontine angle should be of prime suspicion in patients with chronic unilateral ones. Wernicke encephalopathy was most common in patients with acute bilateral combined vestibulopathy while degenerative disorders should be considered in chronic bilateral ones. Since the head impulse test (HIT) is mostly positive in combined vestibulopathy, signs of central vestibular dysfunction other than negative HIT should be sought carefully even in patients with obvious clinical or laboratory features of peripheral vestibulopathy.
Assessment of cerebral dopamine D 2 / 3 -receptors in patients with bilateral vestibular failure
Authors: Jansen Nathalie L. , Feuerecker Regina , Becker-Bense Sandra , Zwergal Andreas , Wulff Melanie , Xiong Guoming , Wängler Björn , Cumming Paul , Bartenstein Peter , Dieterich Marianne , la Fougère Christian
Published: December 2019

Background: Absence of peripheral vestibular input in bilateral vestibular failure (BVF) has been suggested to induce plastic reorganization in various brain regions. Among several neurotransmitters, dopamine is known to play a key role in cortico-striatal-sensorimotor processing. However, the role of dopamine in vestibular plasticity is scantly documented. Objective: Assessment of D 2 / 3 -receptors in patients with BVF. Methods: D 2 / 3 -receptor-PET using [ 18 F]fallypride and MRI examinations were performed in 12 BVF-patients and 13 healthy controls. Results: BVF-patients showed reduced D 2 / 3 -receptor availability (approximately 40%) in the temporo-parieto-occipital cortex bilaterally, including the multisensory vestibular cortex and visual motion-sensitive areas (MT/MST), as well as in the striatum and the right thalamus. Longer illness duration was associated with bilaterally lower D 2 / 3 -receptor availability in the middle/superior temporal gyrus (GTm/s). D 2 / 3 -receptor availability in the right GTm/s and bilateral insula decreased with severity of symptoms. BVF-patients with oscillopsia showed reduced D 2 / 3 -receptor availability in the right MT/MST and midbrain tectum. Conclusions: Reduced D 2 / 3 -receptor availability in multisensory vestibular cortical network areas and basal ganglia may indicate a receptor down-regulation due to the lack of peripheral vestibular input. The more pronounced decline in D 2 / 3 -receptor availability in the multisensory vestibular cortex in patients with prolonged illness suggests the occurrence of progressive changes in dopamine transmission.
Selective otolith dysfunctions objectively verified
Authors: Manzari Leonardo , MacDougall Hamish G. , Burgess Ann M. , Curthoys Ian S.
Published: December 2019

Vertigo and vigorous horizontal spontaneous nystagmus in a presenting patient is usually taken to indicate unilaterally reduced horizontal canal function. However here we report results which question that presumption. In three such patients with an acute vestibular syndrome, complete testing of all peripheral vestibular sense organs using new tests of canal and otolith function (vHIT and VEMPs) showed that semicircular canal function was normal, but that there were unilateral otolithic deficits which probably caused their acute syndrome.
Saccadic Dysmetria is Similar in Patients with a Lateral Medullary Lesion and in Monkeys with a Lesion of the Deep Cerebellar Nucleus
Authors: Straube Andreas , Helmchen Christoph , Robinson Farrel , Fuchs Albert , Büttner Ulrich
Published: December 2019

Some of the clinical hallmarks of lateral medullary infarction — Wallenberg's syndrome — are saccadic dysmetria, smooth pursuit deficit, and lateropulsion of the body. Similar movement disorders are seen in monkeys after local unilateral injection of GABAergic drugs in the caudal fastigial nucleus of monkeys. These include an ipsilateral saccadic hypermetria and a contralateral saccadic hypometria as well as cogwheel smooth pursuit eye movements toward the contralateral side and an ipsiversive lateropulsion of the body. It was previously suggested that the lateral medullary infarction causes a lesion of climbing fibers to the cerebellum. This lack of climbing fiber input increases the activity of ipsilateral Purkinje cells, which consequently provide too much inhibition of the deep cerebellar nuclei.
Supplementation of the Human Vestibulo-Ocular Reflex by Visual Fixation and Smooth Pursuit
Authors: Leigh R. John , Huebner William P. , Gordon Jacob L.
Published: December 2019

In studies over the past 30 years, D.A. Robinson and colleagues established that the dynamic characteristics of smooth pursuit eye movements (SP) are different at the onset from those at the cessation of the response. They proposed that cessation of SP was due to a separate fixation system. During head movements, both fixation and SP may contribute to gaze stabilization. We investigated the relative contributions of fixation and SP to the “visually enhanced” vestibulo-ocular reflex (VVOR) using a paradigm requiring a transition from VVOR to combined eye-head tracking (CEHT). We found, in four normal subjects, that ringing typical of SP generally did not occur during VVOR, but that it often appeared after the transition to CEHT. The findings were different in two patients with absent peripheral vestibular function; ringing typical of SP occurred always during VVOR but disappeared during the onset of CEHT. These results can be explained by a model in which an internal representation of target velocity serves as input to parallel SP and fixation systems, and as the determinant of which of the two systems will provide the command signal. Interpretation of our data using this model indicates that either fixation or SP systems may “visually enhance” the VOR, depending on the magnitude of retinal error velocity that remains after vestibular eye movements have been generated.
Model of Coupled or Dissociated Eye-Head Coordination
Authors: Ron S. , Berthoz A. , Gur S.
Published: December 2019

Tight coupling between eye and head movements have been observed in response to a single visual target offset or a single flash. On this basis, when the visual stimulus consists of two successive steps or flashes in the same (horizontal) direction, either increasing in eccentricity or decreasing in eccentricity, gaze should be due to concomitant eye and head angular displacement. The main findings were that in response to increasing eccentricity stimulus, the majority of the gaze movement had a staircase pattern, and to decreasing eccentricity stimulus, a pulse-step pattern. Some responses were one gaze movement to the final target (or flash) offset. In all these responses, eye and head were tightly coupled. In some cases, however, in response to two flashes or two successive steps decreasing in eccentricity, the initial eye and head movements were dissociated: eye and head were directed to different offsets. Current eye-head models assume a strong coupling between the head displacement and the eye saccade. We have modified the Laurutis and Robinson model to accommodate the new findings of saccade-VOR cooperation and eye-head dissociated responses; We suggest that when gaze falls short of the target offset, the retinal error signal is not only fed to the saccadic system but also partially suppresses the VOR gain control. This allows for “corrective VOR” movements after the gaze saccade has occurred. To accommodate eye-head dissociation movements, we introduced a switch and a delay in the path to the saccadic system and in the path to the head system. The switches and the delays are controlled by higher functions, and their coordination depends on the subject's motor strategy.
Eye Position Signals in the Vestibular Nuclei: Consequences for Models of Integrator Function
Authors: McConville K. , Tomlinson R.D. , King W.M. , Paige G. , Na E.-Q.
Published: December 2019

Recordings from neurons in the vestibular nuclei indicate that the cells that carry eye position signals encode the position of a single eye (either ipsilateral or contralateral) during both conjugate and vergence eye movements. The fact that the vestibular nuclei are aware of the positions of each eye is not surprising as the otolith-based linear vestibulo-ocular reflex is known to change its behaviour as a function of uniocular eye position. This result suggests that the signal coming from the oculomotor velocity-to-position integrator specifies the position of each eye during vergence movements and thus must receive a vergence velocity input along with its conjugate velocity inputs. As there is no vergence system in laterally eyed animals, we have proposed two possible models of integrator arrangement that could have developed from conjugate directional (rather than uniocular) integrators in lower animals without frontally mounted eyes. Both of these models explain the existence of near-response cells and produce the required bidirectional gaze paretic nystagmus following unilateral lesions of one integrator. The models also make specific and different predictions concerning the effects of unilateral integrator lesions on the behaviour of the vergence system and thus make suggestions for further experiments.