Mass transfer in blood oxygenators using blood analogue fluids

Mass transfer correlations for hollow fiber blood oxygenators have been determined experimentally using Newtonian and non-Newtonian blood analogue fluids. The Newtonian fluids consisted of deionized water and glycerol/water mixtures. The non-Newtonian fluids were prepared by adding small amounts of xanthan gum to the Newtonian blood analogue fluids. The rheological behavior of the non-Newtonian blood analogue fluids was modeled using the power law. The diffusion of oxygen into and out of the Newtonian and non-Newtonian blood analogue fluids has been studied. The liquid stream flowed outside and across bundles of woven hollow fibers, while the gas stream flowed inside the fibers.     

Best practices in regulation of blood and blood products

The need for blood regulation arises from the inherent risks of blood transfusion, which are minimized through implementation of standards. Regulatory oversight is advocated by the World Health Organization (WHO) as an essential element of any blood system to ensure such standards are met. The WHO Blood Regulators Network has developed "Assessment Criteria for National Blood Regulatory Systems" that describe the legal authority and functions of a fully competent blood regulator. The core functions include licensing and/or registration of blood establishments, marketing approval of blood products, oversight of all associated substances and devices, control of clinical trials, access to an independent laboratory for product assessments, lot release, and hemovigilance systems. Regulatory policy-making for blood safety is needed to address emerging threats, to consider the risks and benefits of new products and technologies, and to respond to adverse events. Structured policy-making processes are essential to ensure that decisions are science-based, with appropriate consideration of relevant economic and social factors. Decision making is especially challenging in situations of scientific uncertainty, where prudent precautionary measures may be appropriate based on assessments of risk and feasibility of meaningful interventions. There is international interest in finding a common framework for addressing blood safety decisions.     

Common origins of blood and blood vessels in adults?

After embryonic development, the vast majority of cells are differentiated and all organs are in place. Growth of the organism then ensues and continues until adulthood, whereupon cell division largely ceases. In some tissues, notably the bone marrow, skin, and gut, cell proliferation continues throughout life to replace cells lost by attrition. This regeneration is fueled by rare, long-lived, and largely quiescent stem cells that give rise to committed progenitors, which in turn generate large numbers of fully differentiated cells. Mounting evidence suggests that such cells can significantly contribute to tissue repair and regeneration in adults and may therefore prove beneficial for autologous cell and gene therapies. This review focuses on the potential of adult stem cells to give rise to hematopoietic and vascular cells. We discuss evidence that a highly purified population of adult stem cells, termed SP cells, serves as a hematopoietic progenitor and can contribute to vascular regeneration after injury. We also discuss the potential relationship of these cells to the embryonic hemangioblast.     

Role of potassium in regulating blood flow and blood pressure

Unlike sodium, potassium is vasoactive; for example, when infused into the arterial supply of a vascular bed, blood flow increases. The vasodilation results from hyperpolarization of the vascular smooth muscle cell subsequent to potassium stimulation by the ion of the electrogenic Na+-K+ pump and/or activating the inwardly rectifying Kir channels. In the case of skeletal muscle and brain, the increased flow sustains the augmented metabolic needs of the tissues. Potassium ions are also released by the endothelial cells in response to neurohumoral mediators and physical forces (such as shear stress) and contribute to the endothelium-dependent relaxations, being a component of endothelium-derived hyperpolarization factor-mediated responses. Dietary supplementation of potassium can lower blood pressure in normal and some hypertensive patients. Again, in contrast to NaCl restriction, the response to potassium supplementation is slow to appear, taking approximately 4 wk. Such supplementation reduces the need for antihypertensive medication. "Salt-sensitive" hypertension responds particularly well, perhaps, in part, because supplementation with potassium increases the urinary excretion of sodium chloride. Potassium supplementation may even reduce organ system complications (e.g., stroke).     

Direct collection of information during blood donation in blood mobiles

Direct data storage, in the presence of the donor, ensures a realistic reliability and erases any deferred interpretation of the essential information for a good donation identification. Computers can help relieve this restraint. Indeed the evolution of microcomputers (increased capacity and power, decreased weight and volume, and good performance in any use makes them more and more accurate. Associated use of barcodes and microcomputers gives a nonmanual non-human line of words: donor-donation-analysis-blood products-patient. We found, working that way, the following advantages: Information secured. No deferred inputs. Instart comparison of the information on the donor's past history. Accurate donation-donor connection. Such a system represents one more step towards a continuous line of treatment from Donor to Patient in regard of Blood Transfusion Safety.     

Metabolic changes in blood in pulmonary tuberculosis patients from various blood groups

285 Patients suffering from the respiratory tract organs primary tuberculosis were subjected to the tests on definition of blood groups according to AB0 system, as well as its total proteolytic activity, alpha 1-antitrypsin, ceruloplasmin, general haptoglobin, lysozyme, malonic dialdehyde and diene conjugates levels were estimated. The sick persons as compared with the healthy ones were defined to reveal a tendency to increase of the persons with 0(I)- and B(III)-blood groups and decrease of those ones with A(II)-groups. Independently on the pulmonary tuberculosis patients phenotypic index their tested blood biochemical indices levels increase. As an exception is the proteolytic activity of the persons with B(III)- blood group, and also alpha 1-antitrypsin and lysozyme--with 0(I) and AB(IV) groups, in this case their rates failed to exceed the norm confidential interval. The blood metabolic parameters were defined as independent on its group.     

Changes in blood lipids and blood pressure during adolescence.

A total of 625 adolescents from three general practices participated in a cross-sectional study of cardiovascular disease risk factors. The girls had higher serum total and high density lipoprotein (HDL) cholesterol concentrations than the boys, while the boys had higher serum triglyceride concentrations. Smoking (equally prevalent in both sexes) was associated with lower HDL cholesterol concentrations, particularly in boys, while in girls use of oral contraceptives was associated with higher total cholesterol and lower HDL cholesterol concentrations showed striking associations with age, height, and sexual maturation in boys, but not in girls. Triglyceride concentrations were associated with age in boys. Systolic blood pressure and serum urate concentrations were higher in boys and rose steeply with age, but no age association was seen for urate concentrations or systolic blood pressure in girls or for diastolic pressures in either sex. Girls, however, had higher diastolic pressures. There was a strong association between urate concentration and the other cardiovascular disease risk factors, especially HDL cholesterol. Adolescence is associated with considerable changes in cardiovascular disease risk factors, and there are striking sex differences in these changes.     

Expression profiling of circulating non-red blood cells in embryonic blood

Background  

In addition to erythrocytes, embryonic blood contains other differentiated cell lineages and potential progenitor or stem cells homed to changing niches as the embryo develops. Using chicken as a model system, we have isolated an enriched pool of circulating non red blood cells (nRBCs) from E4 and E6 embryos; a transition period when definitive hematopoietic lineages are being specified in the peri-aortic region.     

Study on blood constitutive parameters in different blood constitutive equations

A method is proposed to study the steady blood constitutive equation (BCE). With the method several BCEs are tested and Quemada, Bi-exponent and K-L equations are found to be well in agreement with the hemorheological characteristics of human and canine blood and these equations may be well used in hemorheology and hemodynamics. In addition, the potential clinical applications of some blood constitutive parameters (BCPs) are discussed. It is found that the hematocrit can significantly affect the BCPs: K(A) = alpha2/alpha1, Q(A) = eta0/eta(infinity), R(A) = etaA/eta(e) - 1, which means relative viscosities and they may be related to RBC aggregative level. Moreover, we also show that the parameters are related to the RBC aggregative strength and level.     

Demands for preserved blood and blood transfusions in planned operations

An analysis is described which deals with the relation existing between those amounts of stored blood which are demanded and used in serological cross tests on the one hand and that transfused stored blood used in operations which can be planned in selected clinics on the other hand by accounting for the demanding parameters of 3 stored blood items and less and 4 stored blood items and more.