Relationship between power law coefficients and major blood constituents affecting the whole blood viscosity

The present work concerns a quantitative analysis of parameters that affect apparent blood viscosity at different low shear rates, i.e, between 1 s⁻¹ and, 100 s⁻¹. Viscosity profile of a large number of blood samples from thromboembolic stroke cases and age and sex matched healthy controls were studied which confirmed non-Newtonian power law behaviour of blood. The power law coefficients,n andk, which are unique to each blood sample, were related with blood viscosity parameters in the form of a mathematical equation by performing non-linear regression analysis. It was possible to calculaten andk of power law model by supplying the values of major blood constituents in the equation obtained for stroke and controls. The calculation ofn andk of a blood sample using the equation obtained, provided a quick information on its apparent viscosity values at any given shear rate without viscometry. The calculated and the experimental viscosity were found in good agreement within a permissible error range. The relation obtained between power law coefficients and major blood constituents in the present investigation would give a quantification of different blood viscosity parameters contributing to the resistance to flow of blood. Such an analysis may be considered as a scientific basis for the study of blood fluidity in different disease conditions.     

Binding features of diacetylmorphine (heroin) in whole blood and in blood fractions.

Binding features of heroin in whole blood and in blood fractions were delineated by measuring the selective spin-lattice relaxation rates of heroin protons in physiologic conditions. Interaction with some receptor located in the whole human blood or in the human plasma was detected and the apparent binding constant calculated (K = 39 mol-1 dm3). Inferences about molecular dynamics of the bound heroin could be also gained.     

Beneficial effect of fish oil on blood viscosity in peripheral vascular disease.

Reports suggest that the low incidence of ischaemic heart disease in Greenlandic Eskimos is related to the effect of a diet rich in eicosapentaenoic acid on platelet reactivity and plasma lipid concentrations. A double blind randomised investigation was therefore conducted of the effects on blood viscosity of dietary supplementation with an oil rich in this fatty acid (1.8 g/day, given as fish oil) and an eicosapentaenoic acid poor oil (as corn/olive oil) in patients with peripheral arterial disease. A statistically significant reduction in whole blood viscosity was observed at seven weeks in those patients receiving the eicosapentaenoic acid rich oil. No changes in plasma viscosity, haemoglobin concentration, packed cell volume, or platelet count were seen. A significant fall in plasma triglyceride concentration was also noted only in the patients receiving oil rich in eicosapentaenoic acid; plasma concentrations of cholesterol and high density lipoprotein cholesterol were unchanged. It is concluded that rheological changes that result from a diet rich in eicosapentaenoic acid may contribute to the suggested protective effects of such a diet against arterial disease and that such changes are of potential therapeutic importance in established arterial disease.     

The prognostic significance of whole blood global and specific DNA methylation levels in gastric adenocarcinoma

Background

Epigenetics, particularly DNA methylation, has recently been elucidated as important in gastric cancer (GC) initiation and progression. We investigated the clinical and prognostic importance of whole blood global and site-specific DNA methylation in GC.

Methods

Genomic DNA was extracted from the peripheral blood of 105 Omani GC patients at diagnosis. DNA methylation was quantified by pyrosequencing of global DNA and specific gene promoter regions at 5 CpG sites for CDH1, 7 CpG sites for p16, 4 CpG sites for p53, and 3 CpG sites for RUNX3. DNA methylation levels in patients were categorized into low, medium, and high tertiles. Associations between methylation level category and clinicopathological features were evaluated using χ² tests. Survival analyses were carried out using the Kaplan-Meier method and log rank test. A backward conditional Cox proportional hazards regression model was used to identify independent predictors of survival.

Results

Older GC patients had increased methylation levels at specific CpG sites within the CDH1, p53, and RUNX-3 promoters. Male gender was significantly associated with reduced global and increased site-specific DNA methylation levels in CDH1, p16, and p53 promoters. Global DNA low methylation level was associated with better survival on univariate analysis. Patients with high and medium methylation vs. low methylation levels across p16 promoter CpG sites, site 2 in particular, had better survival. Multivariate analysis showed that global DNA hypermethylation was a significant independent predictor of worse survival (hazard ratio (HR) = 2.0, 95% CI: 1.1–3.8; p = 0.02) and high methylation mean values across p16 promoter sites 1–7 were associated with better survival with HR of 0.3 (95% CI, 0.1–0.8; p = 0.02) respectively.

Conclusions

Analysis of global and site-specific DNA methylation in peripheral blood by pyrosequencing provides quantitative DNA methylation values that may serve as important prognostic indicators.     

The clinical significance of class III (suspicious) urine cytology

I. Sternberg, R. Rona, S. Olsfanger, S. Lew and I. Leibovitch The clinical significance of class III (suspicious) urine cytology Background: Urine cytology, combined with cystoscopy, is the mainstay of the diagnosis and surveillance of urothelial carcinoma (UC). While classes I and II urine cytology are considered benign and classes IV and V are considered malignant the clinical significance of class III urine cytology is unclear. We evaluated the positive predictive value of class III urine cytology for concurrent and subsequent UC. Methods: The records of all class III urine cytology cases during a 3‐year period were retrospectively reviewed for the presence of concurrent and subsequent UC, determined by cystoscopy and histological confirmation. Results: Of 111 cases, 54 (48.7%) were associated with concurrent UC and 14 (12.6%) with subsequent UC after an initial evaluation negative for malignancy, with a mean time to diagnosis of 10.8 months. Of 27 cases of class III urine cytology with no prior history of UC, 13 (48.1%) had concomitant UC and none had subsequent UC. Of 84 cases of class III urine cytology with a prior history of UC, 41 (48.8%) had a concomitant diagnosis of UC and 14 (16.7%) developed UC during their follow‐up, leading to a total of 55 (65.5%) cases of UC. Conclusions: Patients with class III urine cytology and a prior history of UC should undergo a full initial evaluation of their urinary tract, and should be followed vigorously if this evaluation is negative for malignancy. Patients without a prior diagnosis of UC and class III urine cytology should also undergo a full initial evaluation, while further larger studies are needed to elucidate the need for further follow‐up in such patients.     

No change of whole blood of plasma viscosity in cardiac patients after subcutaneous calcium heparin.

Whole blood viscosity, plasma viscosity and haematocrit were studied in a group of cardiac patients before and during subcutaneous heparin treatment. No significant change was noted in any of the parameters investigated. Relative viscosity (whole blood viscosity/plasma viscosity ratio) was also unaffected. These data indicate that heparin has no effect on the rheology of blood in vitro.     

Interleukin-8 in whole blood and clinical status in cystic fibrosis

Cytokines and polymorphonuclear leukocytes play a key role in immune mediated inflammation in progressive pulmonary damage due to cystic fibrosis. The aim of this study is to establish a simple measure of the host's propensity to secrete inflammatory cytokines and to correlate this with clinical status. Patients (n=44, median age 16 years) with the DeltaF 508 mutation (homozygous) were grouped according to their Shwachman score: Patients with mild disease (Shwachman score 71-100 points, group A, n=22, median FEV(1) 79%) were compared with those with more severe disease (Shwachman score 41-55 points, group B, n=22, median FEV(1) 55%) and age-matched controls (group C, n=22, median FEV(1) 102%). Whole blood was stimulated with 5 ng of lipopolysaccharide (LPS). Interleukin-8 (IL-8) was measured by chemiluminescent immunometric assay (DPC, Bad Nauheim, Germany). Though there was a significant difference at baseline for IL-8 (median group A/B/C 6.1/30.5/5.8 pg/ml; p<0.001), there was no significant difference after stimulation. Moreover, in Pseudomonas aeruginosa positive (Psa+) patients (n=26) there was a significant negative correlation (r=-0.539; p<0.004) between baseline IL-8 and FEV(1) (%). Clinical course and lung function (in Psa+) correlate with IL-8 levels.     

Pharmacological concentrations of arginine influence human whole blood viscosity independent of nitric oxide synthase activity in vitro

l-Arginine, the natural precursor of NO, is infused in patients to restore endothelial function. Concentrations up to 7.5 mM l-arginine have been measured after parenteral administration. We investigated whether such high concentrations of amino acids influence blood viscosity in vitro. Incubation of whole blood from healthy volunteers with l-arginine, d-arginine, which has no effect on stereospecific NO synthases (NOS), the NOS substrate L-AME, the NOS inhibitor L-NNA, the amino acids l-lysine and l-glutamic acid, and finally NaCl dose-dependently decreased (up to 30% at 10(-2) M) low shear viscosity, which is primarily determined by erythrocyte aggregation. In contrast, the lipophilic NOS inhibitor L-NAME had no effect on low shear viscosity. All molecules failed to influence high shear viscosity, which is primarily determined by red cell deformability, and the erythrocyte shape remained unaltered. We conclude that high concentrations amino acids may decrease blood viscosity at low shear rate independent of NOS activity. This effect may contribute to the improved blood flow after intravascular administration of l-arginine.     

中国健康中年男性全血比粘度参考值与海拔高度的关系

为制定中国健康中年男性全血比粘度参考值的统一标准提供科学依据,本文收集了中国各地用毛细管法测定的健康中年男性全血比粘度参考值,并对其与海拔高度的关系进行了研究,发现随着海拔高度的逐渐增高,健康中年男性全血比粘度参考值也在逐渐的增大,相关性很显著,用一元回归分析的方法推导出了一个回归方程,如果知道了中国某地的海拔高度,就可以用回归方程估算这个地区的健康中年男性全血比粘度参考值。     

The blood vascular system in the head of the herring gull (Larus argentatus)

The structure and development of the blood vascular system in the head of the herring gull (Larus argentatus) have been studied using injection techniques and histological sections. Three different but interconnected divisions of the arterial system are recognized in the adult: the cerebral carotid artery system, the external ophthalmic artery system, and the external carotid artery system. Embryologically, the arterial system is characterized by changes in the relative development of these three divisions; the cerebral carotid system being the most prominent in the first half of the embryonic period. The venous system is divided into two parts, the rostral cephalic system and the caudal cephalic system, which drain separate regions of the head. The Rete ophthalmicum, which is an arteriovenous network associated with the external ophthalmic artery system, can be identified from the fifth day of incubation, and its development appears to be coupled with changes in the arterial supply to the eye. The possibility of a homology between the Rete ophthalmicum of birds and the Rete caroticum of mammals is briefly discussed.     

Relation between blood plasma viscosity and presence of vascular and neurological complications in diabetic Africans

The relation between changes in plasma and serum viscosity and the presence of diabetic vascular and neurological complications was investigated in 50 diabetic Africans. Diabetics with complications had significantly elevated plasma and serum viscosity compared with those of both diabetics without complications and healthy non-diabetics. Hypertension also contributed to the elevation of plasma and serum viscosity in diabetics with complications. Plasma and serum viscosity of diabetics significantly correlated with the number of vascular and neurological complications. Diabetics with cerebrovascular disease had the highest plasma and serum viscosity due to the presence of many complications. The results of this study suggest that changes in plasma and serum viscosity may be associated with abnormalities of vascular and neurological function present in diabetic Africans.