VEGF(164)-mediated inflammation is required for pathological, but not physiological, ischemia-induced retinal neovascularization

Hypoxia-induced VEGF governs both physiological retinal vascular development and pathological retinal neovascularization. In the current paper, the mechanisms of physiological and pathological neovascularization are compared and contrasted. During pathological neovascularization, both the absolute and relative expression levels for VEGF(164) increased to a greater degree than during physiological neovascularization. Furthermore, extensive leukocyte adhesion was observed at the leading edge of pathological, but not physiological, neovascularization. When a VEGF(164)-specific neutralizing aptamer was administered, it potently suppressed the leukocyte adhesion and pathological neovascularization, whereas it had little or no effect on physiological neovascularization. In parallel experiments, genetically altered VEGF(164)-deficient (VEGF(120/188)) mice exhibited no difference in physiological neovascularization when compared with wild-type (VEGF(+/+)) controls. In contrast, administration of a VEGFk-1/Fc fusion protein, which blocks all VEGF isoforms, led to significant suppression of both pathological and physiological neovascularization. In addition, the targeted inactivation of monocyte lineage cells with clodronate-liposomes led to the suppression of pathological neovascularization. Conversely, the blockade of T lymphocyte-mediated immune responses with an anti-CD2 antibody exacerbated pathological neovascularization. These data highlight important molecular and cellular differences between physiological and pathological retinal neovascularization. During pathological neovascularization, VEGF(164) selectively induces inflammation and cellular immunity. These processes provide positive and negative angiogenic regulation, respectively. Together, new therapeutic approaches for selectively targeting pathological, but not physiological, retinal neovascularization are outlined

Physiological Aspects of Genetics

The biological sciences appear to be in the midst of a period of unprecedented progress. An important salient in the advance is the general recognition of the significance of genes in the economy of the organism. The change is largely one in point of view. Many biologists have for a long time appreciated the basic nature of the gene and its role in development and function, but these relatively enlightened individuals have for the most part belonged to a small group of specialists that has tended to remain in isolation. The restraining fences are now being broken down with gratifying rapidity. Biochemists have begun to think in terms of genes because it has been demonstrated to them not only that the chemical reactions which make up living systems are under the fairly immediate supervision of these units of inheritance, but also that genetics provides a powerful tool with which a great deal can be learned about metabolic systems. In bacteriology, too, one sees the effects of an altered point of view toward genetics. Only a few years ago a bacteriologist who so much as raised the question of the existence of genes in bacteria was regarded as a renegade and heretic by his more orthodox fellowmen. It has now become acceptable to speak of bacterial genes; in fact, a recognized field of bacterial genetics has grown up almost over night (l)

The physiological aspects of traumatic shock

Thesis (M.A.)--Boston UniversityThe condition known as shock has been recognized and described by the medical profession for a great many years. Cannon (1923) proposed the descriptive term "exemia," originally applied to a similar condition by Hippocrates. The word shock probably was first used by Latta (1795). Since then there have been many attempts to supply an adequate definition and an explanation for the fatal tendencies ot the condition. In a final explanation of shock there probably will be incorporated much of the knowledge now known. This cause of shock may not be one definite factor but may consist of several factors. Much of the present knowledge has been found to be grossly inadequate in the explanation of other shock-like conditions

Physiological Aspects of Genetics

A considerable amount of evidence indicates that desoxyribonucleic acid is capable of duplicating itself, a property also possessed by genes. (By a self-duplicating material, we mean one which plays some essential role in its own production.) Watson & Crick (1) have proposed a new structure for desoxyribonucleic acid which not only takes into account the existing analytical and x-ray diffraction data but also seems capable of explaining the mechanism of duplication. Their model consists of two helical chains coiled around the same axis, the purine and pyrimidine bases on the inside, the phosphate groups on the outside. The chains are held together by hydrogen bonds between the bases, the adenine residues of either chain being bonded specifically to thymine in the other, and similarly guanine to cytosine. The sequence of bases along one chain is not restricted, but once fixed the sequence along the other chain is determined. This complementarity, which is the most novel feature of the structure, suggests that duplication takes place by separation of the two chains, followed by the synthesis of its complement alongside each chain. The model is supported by recent x-ray diffraction studies (2, 3)

A continuous physiological data collector

COP-DAC system utilizes oxygen and carbon dioxide analyzers, gas-flow meter, gas breathe-through system, analog computer, and data storage system to provide actual rather than average measurements of physiological and metabolic functions

Dietary nitrate reduces skeletal muscle oxygenation response to physical exercise : a quantitative muscle functional MRI study

© 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.Peer reviewedPublisher PD

Psychrometric chart for physiological research

Chart facilitates use of graphical techniques for solving problems involving thermodynamic properties of moist air. The properties are presented, and their units of measurement are listed. Chart presenting conditions at standard atmosphere pressure at sea level is most useful

Physiological Mechanisms Underlying Motion-Induced Blindness

Visual disappearance illusions - such as motion-induced blindness (MIB) - are commonly used to study the neural underpinnings of visual perception. In such illusions a salient visual target becomes perceptually invisible. Previous studies are inconsistent regarding the role of primary visual cortex (V1) in these illusions. Here we provide physiological and psychophysical evidence supporting a role for V1 in generating MIB