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.     

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.     

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 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.     

Thermoregulatory responses and blood viscosity in dehydrated heat-exposed broilers (Gallus domesticus)

This study was to elucidate thermoregulation in dehydrated heat-exposed broilers. When broilers were dehydrated, heat production (HP), comb surface temperature (Tcs) and respiration rate (RR) decreased significantly. Conversely, rectal (Tr) and back skin (Tbs) temperatures, whole blood viscosity (WBV), haematocrit (HCT), plasma protein concentration (PPC) and plasma osmolality (PO) increased. During heat exposure, HP, WBV, HCT and PPC decreased significantly, while Tr, Tcs, Tbs and RR increased. The onset of panting against rectal temperature was delayed in dehydrated birds. These results suggest that dehydration leads to a lower blood volume, resulting in a decrease in blood flow to heat exchange organs and surfaces in broilers. This induces a lower sensible heat loss from extremities, a lower evaporative heat loss and a higher sensible heat loss from trunk, subsequent to regulate their body temperature at a higher level of deep body temperature.