Functional characteristics of normal and pathologic erythrocytes

Polarographic titration in a closed cell of blood samples and concentrated Hb solutions was used to study the regulation of the release of oxygen by the red cell. The effect of temperature, polyethylenglycol and metabolites normally found in the erythrocyte was determined by spectrophotometric and polarographic methods. Some pecularities of O2-transport and release in beta-thalassemia, functional hypoxia and Cooley-disease are described.     

S49 lymphoma wild type and variant clones contain normal calcium dependent regulator.

Calcium dependent regulator is present in wild-type S49 lymphoma cells, in the variant that is deficient in adenylate cyclase activity (AC-), and in the uncoupled variant (UNC). The electrophoretic mobility and the ability to stimulate cyclic nucleotide phosphodiesterase of the calcium dependent regulator from each of these three clones are indistinguishable from those of the modulator protein isolated from bovine brain. Calcium dependent regulator does not appear to be involved in the defect responsible for the UNC or AC- variants.     

Fronto-striatal correlations in normal and pathologic aging of the human brain

In psychically healthy persons of three age groups (30-40, 50-60, 80-90 years), as well as in those suffering from Alzheimer's disease (50-60 years) right and left hemispheres formations, including into a single functional system (fields 8, 10, 47 and the nucleus caudatus) have been investigated. Using the series of frontal paraffin sections 20 mcm thick, stained after Nissl and Bielschowsky methods, cyto-glioarchitectonics and neuronal composition of the structures mentioned have been studied. In 0.001 mm3 of the brain substance, in cortical layers II and V and in the nucleus caudatus head density of neurons, perineuronal glia, neurons with lipofuscin, size of the neurons have been calculated. Various degree of manifestation of morphological changes is revealed in different stages of the single functional system. These changes are directly proportional to the organizational level of the structures studied and depend on the stage of the process, on accompanying diseases and individual peculiarities of the person. They are more intensive in the frontal fields and weaker in the nucleus caudatus. At Alzheimer's disease they are more distinct in the associative fields 10 and 47, at normal ageing--in the motor structures--in the field 8 and then in the nucleus caudatus. Spreading of the pathological process occurs with a predominant damage of neurons of cholinergic origin.     

Proprioception,the regulator of motor function

In animals, proper locomotion is crucial to find mates and foods and avoid predators or dangers. Multiple sensory systems detect external and internal cues and integrate them to modulate motor outputs. Proprioception is the internal sense of body position, and proprioceptive control of locomotion is essential to generate and maintain precise patterns of movement or gaits. This proprioceptive feedback system is conserved in many animal species and is mediated by stretch-sensitive receptors called proprioceptors. Recent studies have identified multiple proprioceptive neurons and proprioceptors and their roles in the locomotion of various model organisms. In this review we describe molecular and neuronal mechanisms underlying proprioceptive feedback systems in C. elegans, Drosophila, and mice.     

The presence of polysaccharide in normal human gastric mucus.

Polysaccharide material was found in the proteolysis glycopolypeptide fraction from normal human gastric mucus. The polysaccharide was identified by carbohydrate and amino acid analyses, by elemental analysis and from its behaviour on density-gradient ultracentrifugation. The polysaccharide is polydisperse with a weight-average molecular mass of 300 000 Da. Over 85% of the polysaccharide consists of galactose, and this represents 26% of all the galactose present in the fractions after beta-elimination with reduction of the glycopolypeptide material.     

Vascular permeability factor: a unique regulator of blood vessel function.

Vascular permeability factor (VPF), also known as vascular endothelial growth factor (VEGF), is a potent polypeptide regulator of blood vessel function. VPF promotes an array of responses in endothelium, including hyperpermeability, endothelial cell growth, angiogenesis, and enhanced glucose transport. VPF regulates the expression of tissue factor and the glucose transporter. All of the endothelial cell responses to VPF are evidently mediated by high affinity cell surface receptors. Thus, endothelial cells have a unique and specific spectrum of responses to VPF. Since each of the responses of endothelial cells to VPF are also elicited by agonists, such as bFGF, TNF, histamine and others, it remains a major challenge to determine how post-receptor signalling pathways maintain both specificity and redundancy in cellular responses to various agonists.