On the basis of solid-state aluminium-27 nuclear magnetic resonance measurements a new organo-aluminium complex in coal substance was discovered in the solid extracts obtained both from the Ostrava-Karviná bituminous coal and the North Bohemian Basin brown coal. In the 27 Al MAS NMR spectra it was found that the significant chemical shift at 13.6-14.6 ppm corresponds with that obtained for the aluminium hexaphenoxide complex (14.2 ppm). Therefore, organo-aluminium complex with hexa-coordination to oxygen is present in coal substance., Pavel Straka., and Obsahuje bibliografické odkazy
In this review, we discuss the role of pulmonary surfactant in the host defense against respiratory pathogens, including novel coronavirus SARS-CoV-2. In the lower respiratory system, the virus uses angiotensin-converting enzyme 2 (ACE2) receptor in conjunction with serine protease TMPRSS2, expressed by alveolar type II (ATII) cells as one of the SARS-CoV-2 target cells, to enter. ATII cells are the main source of surfactant. After their infection and the resulting damage, the consequences may be severe and may include injury to the alveolar-capillary barrier, lung edema, inflammation, ineffective gas exchange, impaired lung mechanics and reduced oxygenation, which resembles acute respiratory distress syndrome (ARDS) of other etiology. The aim of this review is to highlight the key role of ATII cells and reduced surfactant in the pathogenesis of the respiratory form of COVID-19 and to emphasize the rational basis for exogenous surfactant therapy in COVID-19 ARDS patients.
The abundance, diet, and prey relationships of American mink Mustela vison were studied in the Słońsk Reserve (W Poland) on two plots: shore and reservoir. Estimated mink number within the Reserve was 69 in autumn–winter 1998/1999 and 50 during spring 1999. The diet of American mink consisted mainly of mammals, birds and fish. In autumn–winter, birds formed 4–16%, whereas mammals constituted up to 56% and fish up to 62% of the biomass consumed, depending on the plot. In spring and summer, however, birds formed 45–60% of the biomass consumed in the reservoir and 35–46% of the biomass taken by mink on the shore. The European coot Fulica atra was the most frequently consumed prey. In spring, mink removed 7.8% (N=278 killed birds) of coots nesting in the Reserve, 1.8% (N=9) of breeding grebes Podiceps spp. and 11.2% of ducks (N=93 taken birds). On straw platforms only 13.6% of greylag geese Anser anser broods were successful. From 35 to 77% of the nests on straw platforms were destroyed by mink. In wooden boxes 46.4% of mallard Anas platyrhynchos and 33.3% of shelduck Tadorna tadorna nests were successful. American mink destroyed 22–40% of the nests in boxes. However, the arrival of American mink to the Słońsk Reserve has not resulted in a noteworthy decrease in waterfowl populations.
In this article, the author traces how the lessons of the Munich Agreement of September 1938 (on the basis of which Czechoslovakia was forced to cede the predominantly ethnic-German Sudetenland to Nazi Germany) were projected into US foreign policy. In Part One of the essay, based on published sources and unpublished documents from American archives, the topic is covered from the late 1930s to the outbreak of the Korean War (which is discussed in Part Two, to be published in the next issue of Soudobé dějiny). The author looks at immediate American reaction to the North Korean attack on South Korea in June 1950, and then returns to autumn 1938 to test his hypothesis that behind the unusual unity of this reaction was the ingrained negative attitude of the United States to the policy of appeasement. He demonstrates that since the late 1930s the terms ‘Munich’ and ‘appeasement’ have remained forever linked in US policy and US public discourse, and he discusses the transformations of the perception of the two concepts during the Second World War, after the war, and at the beginning of the Cold War. The lessons of Munich, he argues, have drawn on the idealistic as well as the pragmatic sources of US policy, because they stem from the conviction that appeasement is immoral and does not pay. Whereas in Roosevelt’s policy the general lesson was not to allow Hitler’s expansion, Harry S. Truman, Roosevelt’s successor in the White House, had to use the lessons, despite his own self-restraint, to try to counter the steps of a wartime ally, Stalin’s Soviet Union. The Communist take-over in Czechoslovakia in February 1948 and the blockade of the western sectors of Berlin beginning in the summer of that year were important events on this path.The author further considers the infl uence of this factor on the US approach taken in the Korean War in the early 1950s. He seeks to demonstrate that the decision of the Truman Administration to substantially intervene in this confl ict was a direct consequence of the negative attitude to the policy of appeasing an aggressor. This attitude was also shared by the American public, regardless of party affi liation and political sympathies. Arguments based on the rejection of appeasement, however, soon began to be used by the Republicans as ammunition in the election campaign against the incumbent Democrats and the choice of strategy also became a matter of dispute in the choice of strategy on the Korean battlefi eld after China entered the war. Whereas the White House wished to avoid an unlimited confl ict with China, the Commander-in-Chief of the United Nation Command in Korea, General Douglas MacArthur (1880–1964), was in favour of an uncompromising approach and in fact ceased to obey President Harry S. Truman (1884-1972). After being relieved of his command by Truman, MacArthur became the chief critic of his policies and a hero of Truman’s Republican opponents. In spring 1951, the Republicans organized a special Senate committee hearing on the circumstances of MacArthur’s suspension. The author looks in detail at this exceptional clash in post-war US domestic politics, which was meant to be triumphantly used against MacArthur, but gradually changed into a debacle in consequence of, among other things, the compelling testimonies of Secretary of State Dean Acheson (1893-1971) and Secretary of Defense George C. Marshall (1880-1959). In his conclusion, the author seeks to demonstrate how other US presidents returned to the ‘lessons of Munich’, and he argues that these lessons became Truman’s lasting political legacy and as such became fi rmly rooted in American political discourse. and Přeložil: Jiří Mareš
In laboratory experiments, conspecific excretions and ammonia solutions evoked avoidance reactions in tadpoles of three anuran species, Bufo bufo, Rana temporaria, and Rana arvalis . A differential sensitivity of ammonia chemoreception was determined for two anuran species. For Bufo bufo tadpoles, these characteristics at ammonia backgr ound concentration of 0.2 mg/l lied in the range 150 % < dI/I < 500 %, and for background of 0.4 mg/l the value lied in th e range 400 % < dI/I < 500 %. For Rana temporaria tadpoles, differential threshold against ammonia background concentration of 0. 15 mg/l was close to 200 % and against background ammonia concentration of 1.1 mg/l was close to 100 %. These results suggest that such sensitivity of both anurans is sufficient for using ammonia in intra- and interspecies communication., Y. B. Manteifel, E. I. Kiseleva., and Obsahuje bibliografii a bibliografické odkazy
Metabotropic glutamate receptors (mGluRs) represent a potential therapeutic target. Possible anticonvulsant action of AMN 082, an agonist of mGluR7 subtype, was studied in immature rats using pentylenetetrazol (PTZ)-induced seizures as a model. Five age groups of rats (7-, 12-, 18-, 25-day-old and adult animals) were pretreated with AMN 082 in doses of 0.5, 1, 2, and 5 mg/kg i.p. and 30 min later PTZ was administered (100 mg/kg s.c.). Controls received saline instead of the agonist. AMN 082 did not exhibit clear anticonvulsant action with the exception of suppression of the tonic phase of generalized tonic-clonic seizures (GTCS) in 12-day-old rats. Shorter latencies of GTCS after AMN 082 pretreatment indicate a proconvulsant action. Involuntary movements (mostly tremor) appeared after AMN 082 before PTZ administration, therefore we performed another experimental series with AMN 082 only (1, 2, 5, and 10 mg/kg i.p.). During 60-min observation period tremor appeared in all age groups; sensitivity to this action decreased with age from the 2 mg/kg dose in 7- and 12-day-old rats to the 10 mg/kg dose in adult rats. Mixed anti- and proconvulsant actions of AMN 082 together with unwanted motor effects makes clinical use of this drug highly improbable., Pavel Mareš., and Obsahuje bibliografii a bibliografické odkazy
Three amoeba species were isolated from 3 out of 193 farmed tilapias, Oreochromis niloticus (L.), screened for the presence of free-living amoebae in parenchymatous organs. Hartmannella vermiformis Page, 1967 and Rosculus ithacus Hawes, 1963 were isolated from the kidney tissue. The third strain isolated from the liver shared morphological features of Mayorella and Platyamoeha spp. and therefore its taxonomic position has not been determined as yet. Pathogenicity of cloned strain of H. vermiformis was proved in two fish hosts.
Amoebae were found to cause severe gill tissue damage in turbot, Scophthalmus maximus L. from a grow-out facility in northwestern Galicia (Spain). The nature and extent of lesions along with negative results of bacteriological and virological examination made this agent responsible for mortalities in four turbot stocks supplied with water from a single source. We present our findings, although we failed to isolate amoebae, since there was a clear evidence of their primary role in the development of disease condition and occurrence of mortalities. In addition, this is a record both of a new host endangered by amoebae in intensive cultures and pathogenesis of the gill lesions.