Search results for "physiologic"

Über den adäquaten Reiz des Bogengangsystems

1953

An analysis is given of the processes in the semicircular canals during adequate stimulation, emphasizing especially the forces acting on the cupula itself. In this way it is possible to understand the physical and physiological phenomena in straight-lined and rotation movements.

Untersuchungen �ber die Einwirkung von verschiedenen Pharmaka auf die Spontanrhythmik des isolierten H�hneramnion

1954

1. Das isolierte Huhneramnion nach Baur eignet sich gut, um Fragen nach der Entstehung der Erregung, deren Weiterleitung und Koordination, dem Angriffspunkt und der Wirkungsweise von Pharmaka zu prufen, da es sich um ein nervenfreies, rhythmische Kontraktionen ausfuhrendes Organ handelt, das praparativ leicht zu handhaben ist. 2. Auf die erregende Wirkung von Acetylcholin, Nicotin und Bariumionen sind d-Tubocurarin, Decamethonium, Atropin, Hexamethonium und Pentamethonium ohne Einflus. 3. Papaverin und Chinin hemmen die genannten erregenden Verbindungen reversibel. 4. Bariumionen fuhren zu Storungen in der Regelmasigkeit der rhythmischen Kontraktionen. Die Deutung dieses Effektes wird in de…

Taking Advantage of Viral Immune Evasion: Virus-Derived Proteins Represent Novel Biopharmaceuticals

2006

In healthy individuals, natural and adaptive immune responses are able to control virus entry into the host. In particular, CD8(+)-mediated cytotoxicity, sustained by the intervention of CD4+ cells, represents the major key event leading to virus eradication. On the other hand, viruses are able to evade from host immune response via several mechanisms, and special emphasis will be placed on hepatitis C virus and chronic Epstein-Barr infections also in view of personal data. Virokines, viroreceptors, and serpins greatly contribute to viral immune escape, and, among virokines, interleukin (IL)-10 has been object of intensive studies. Finally, all these products have been used as biopharmaceut…

Effect of nutritional imbalances on cytochrome P-450 isozymes in rat liver

1988

Male Sprague-Dawley rats were fed for six weeks either a control diet containing 22% casein (C) and 5% fat (F) or a low-protein diet (6% C, 5% F) or high-lipid diet (30% C, 30% F). A group of rats received a control diet containing 50 ppm of Phenoclor DP6. Three major forms of cytochrome P-450, UT 50, BP 3a and MC 2 were purified from livers of DP6-fed rats and only two forms, UT 50 and PB 3a, were purified from control and dietary groups. The amino acid composition and the catalytic activities towards all substrates tested were only significantly modified in the purified UT 50 P-450 isozyme from rats fed the low-protein diet. The N-terminal sequence analysis shows that cytochrome P-450 UT …

Pharmacological Properties of Polyphenols: Bioavailability, Mechanisms of Action, and Biological Effects in In Vitro Studies, Animal Models, and Huma…

2021

Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2227-9059/9/8/1074 Este artículo de investigación pertenece al número especial "Oxidative Stress and Inflammation: From Mechanisms to Therapeutic Approaches 2.0". Drugs are bioactive compounds originally discovered from chemical structures present in both the plant and animal kingdoms. These have the ability to interact with molecules found in our body, blocking them, activating them, or increasing or decreasing their levels. Their actions have allowed us to cure diseases and improve our state of health, which has led us to increase the longevity of our species. Among the molecules with pharmacological activity …

From foes to friends: Viral infections expand the limits of host phenotypic plasticity

2020

Phenotypic plasticity enables organisms to survive in the face of unpredictable environmental stress. Intimately related to the notion of phenotypic plasticity is the concept of the reaction norm that places phenotypic plasticity in the context of a genotype-specific response to environmental gradients. Whether reaction norms themselves evolve and which factors might affect their shape has been the object of intense debates among evolutionary biologists along the years. Since their discovery, viruses have been considered as pathogens. However, new viromic techniques and a shift in conceptual paradigms are showing that viruses are mostly non-pathogenic ubiquitous entities. Recent studies hav…

Regulation of Phenotypic Switching and Heterogeneity in Photorhabdus luminescens Cell Populations.

2019

Phenotypic heterogeneity in bacterial cell populations allows genetically identical organisms to different behavior under similar environmental conditions. The Gram-negative bacterium Photorhabdus luminescens is an excellent organism to study phenotypic heterogeneity since their life cycle involves a symbiotic interaction with soil nematodes as well as a pathogenic association with insect larvae. Phenotypic heterogeneity is highly distinct in P. luminescens. The bacteria exist in two phenotypic forms that differ in various morphologic and phenotypic traits and are therefore distinguished as primary (1°) and secondary (2°) cells. The 1 cells are bioluminescent, pigmented, produce several sec…

2013

Are dreams subjective experiences during sleep? Is it like something to dream, or is it only like something to remember dreams after awakening? Specifically, can dream reports be trusted to reveal what it is like to dream, and should they count as evidence for saying that dreams are conscious experiences at all? The goal of this article is to investigate the relationship between dreaming, dream reporting and subjective experience during sleep. I discuss different variants of philosophical skepticism about dream reporting and argue that they all fail. Consequently, skeptical doubts about the trustworthiness of dream reports are misguided, and for systematic reasons. I suggest an alternative,…

In Vitro Analysis of the Two-Component System MtrB-MtrA from Corynebacterium glutamicum▿ †

2007

ABSTRACT The two-component system MtrBA is involved in the osmostress response of Corynebacterium glutamicum . MtrB was reconstituted in a functionally active form in liposomes and showed autophosphorylation and phosphatase activity. In proteoliposomes, MtrB activity was stimulated by monovalent cations used by many osmosensors for the detection of hypertonicity. Although MtrB was activated by monovalent cations, they lead in vitro to a general stabilization of histidine kinases and do not represent the stimulus for MtrB to sense hyperosmotic stress.

Rho-mediated activation of PI(4)P5K and lipid second messengers is necessary for promotion of angiogenesis by Semaphorin 4D

2011

Phosphatidylinositol 4-phosphate 5-kinase (PI(4)P5K) is a type I lipid kinase that generates the lipid second messenger phospholipid phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and functions downstream of RhoA in actin organization. It is known to play an essential role in neurite remodeling, yielding a phenotype identical to that seen in cells treated with Semaphorin 4D (Sema4D), a protein that regulates proliferation, adhesion and migration in many different cell types. Plexin-B1, the receptor for Sema4D, activates RhoA in order to generate a pro-angiogenic signal in endothelial cells. Therefore, we looked in human umbilical vein endothelial cells (HUVEC) to determine if Plexin-B1 e…