Anaesthetic Impairment of Immune Function Is Mediated via GABAA Receptors

GABA(A) receptors are members of the Cys-loop family of neurotransmitter receptors, proteins which are responsible for fast synaptic transmission, and are the site of action of wide range of drugs. Recent work has shown that Cys-loop receptors are present on immune cells, but their physiological roles and the effects of drugs that modify their function in the innate immune system are currently unclear. We are interested in how and why anaesthetics increase infections in intensive care patients; a serious problem as more than 50% of patients with severe sepsis will die. As many anaesthetics act via GABA(A) receptors, the aim of this study was to determine if these receptors are present on immune cells, and could play a role in immunocompromising patients.We demonstrate, using RT-PCR, that monocytes express GABA(A) receptors constructed of α1, α4, β2, γ1 and/or δ subunits. Whole cell patch clamp electrophysiological studies show that GABA can activate these receptors, resulting in the opening of a chloride-selective channel; activation is inhibited by the GABA(A) receptor antagonists bicuculline and picrotoxin, but not enhanced by the positive modulator diazepam. The anaesthetic drugs propofol and thiopental, which can act via GABA(A) receptors, impaired monocyte function in classic immunological chemotaxis and phagocytosis assays, an effect reversed by bicuculline and picrotoxin.Our results show that functional GABA(A) receptors are present on monocytes with properties similar to CNS GABA(A) receptors. The functional data provide a possible explanation as to why chronic propofol and thiopental administration can increase the risk of infection in critically ill patients: their action on GABA(A) receptors inhibits normal monocyte behaviour. The data also suggest a potential solution: monocyte GABA(A) receptors are insensitive to diazepam, thus the use of benzodiazepines as an alternative anesthetising agent may be advantageous where infection is a life threatening problem

Why Should We Preserve Fishless High Mountain Lakes?

High mountain lakes are originally fishless, although many have had introductions of non-native fish species, predominantly trout, and recently also minnows introduced by fishermen that use them as live bait. The extent of these introductions is general and substantial often involving many lakes over mountain ranges. Predation on native fauna by introduced fish involves profound ecological changes since fish occupy a higher trophic level that was previously inexistent. Fish predation produces a drastic reduction or elimination of autochthonous animal groups, such as amphibians and large macroinvertebrates in the littoral, and crustaceans in the plankton. These strong effects raise concerns for the conservation of high mountain lakes. In terms of individual species, those adapted to live in larger lakes have suffered a higher decrease in the size of their metapopulation. This ecological problem is discussed from a European perspective providing examples from two study areas: the Pyrenees and the Western Italian Alps. Species-specific studies are urgently needed to evaluate the conservation status of the more impacted species, together with conservation measures at continental and regional scales, through regulation, and at local scale, through restoration actions, aimed to stop further invasive species expansions and to restore the present situation. At different high mountain areas of the world, there have been restoration projects aiming to return lakes to their native fish-free status. In these areas autochthonous species that disappeared with the introduction of fish are progressively recovering their initial distribution when nearby fish-free lakes and ponds are available

Crystallization Process in Porous and Nonporous Vycor Glass

Three stages of thermal and chemical processing of Vycor glass were carried out. Raw material, the glass with small and big pores was studied. In each stage of study various crystallinity degrees of investigated material were obtained. The relation between crystallinity degree and the intensity of o-Ps components was determined. In nonporous material a high correlation between o-Ps intensity and crystallinity degree was found. In porous material the decrease in total o-Ps intensity can be a measure of the crystallinity degree

The concept of parking network for specialized service of refrigerated trucks in Poland : the case study

Artykuł ma na celu stworzenie koncepcji sieci miejsc do specjalistycznej obsługi samochodów-chłodni w miejscu ich postoju na podstawie analizy wybranego studium przypadku. W artykule przeanalizowano kierunki handlu zagranicznego artykułami szybko psującymi się w Polsce. Uzasadniono potrzebę wykorzystania specjalistycznych miejsc do obsługi samochodów-chłodni w miejscach ich postoju. Rozpatrzono studium przypadku, które włącza analizę trzech wybranych tras przewozu artykułów spożywczych. Wykonane obliczenia uwzględniają możliwość poruszania się pojazdów z 2 prędkościami i ograniczenia czasu pracy kierowcy, co pozwoliło zlokalizować możliwe miejsca postoju pojazdów. W wyniku badań stworzono jeden z wariantów koncepcji sieci miejsc obsługi podróżnych, które mogą być wykorzystane do specjalistycznej obsługi samochodów-chłodni.The article aims to create the concept of parking network for specialized service of refrigerated trucks based on the case study analysis. The article investigates the directions of foreign trade of perishable products in Poland. The need to use specialized parking spaces for refrigerated trucks service during their stop was justified. The case study was considered and includes an analysis of three selected routes of food products transportation. The conducted calculations take into account the possibility of vehicles moving with 2 speeds, as well as driver’s working time limitation. That allowed to identify possible location of parking spaces which can be used for specialized service of refrigerated trucks. As the result of research, one of the variants of the concept of rest and service areas network for these transport means was created

Liquation of Vycor Glasses - Study by Positron Annihilation Lifetime Method

Two Vycor glasses of different percentages of the components were liquated between 725 K and 950 K and leached in order to produce pores. Little intermolecular voids characterized by ortho-positronium lifetime valueτ$\text{}_{2}$≈1.5 ns were observed simultaneously. At the first stage of pore formation the intensity I$\text{}_{2}$ decreased considerably for both glasses, while at liquation temperatures higher than 825 K it increased again. The increase in I$\text{}_{2}$ resulted from changes in the properties of the bulk material. The growth ofτ$\text{}_{2}$ in this range of temperatures was also observed