Toxicity of deoxycholate at pH below 7·3 as a potential cancerostatic property

Zusammenfassung Es wird gezeigt, dass die toxische Wirkung von Desoxycholsäure auf Hefe pH-abhängig ist (pH 7.3). Da das pH der Tumoren niedriger ist, wird die Möglichkeit einer krebshemmenden Wirkung diskutiert.     

Reaction of pulmonary macrophages to the presence of foreign protein material in the alveoli during metabolic acidosis

Zusammenfassung Tierexperimentell wurde festgestellt, dass die metabolische Azidose keinen Einfluss auf die Fähigkeit der Alveolarzellen hat, in die Alveolen auszuwandern.     

Nachweis der Bisulfit-Addukte (α-Oxysulfonsäuren) von Carbonylverbindungen in den mit SO2 behandelten Erbsenkeimlingen

Summary The intoxication of 15-day-old green pea seedlings with 1% gaseous SO₂ causes an important concentration fall of some free ketoacids (pyruvic, oxalacetic, -ketoglutaric) and of glyceraldehyde in the roots and shoots. This fall is a consequence of the reaction of these carbonyl compounds with SO₂ in the plant tissue under the formation of bisulphite adducts (-hydroxysulfonic acids), which have been chemically proved and quantitatively estimated.     

A contribution on the effect of noradrenaline on heat production in mice

Zusammenfassung Bei ausgewachsenen Mäusen wurde nach i.p. Noradrenalininjektion die Steigerung der O₂-Aufnahme über den Grundumsatz in der Thermoneutralzone verfolgt. Nach einer Dosis von 1,6 mg/kg wurde ein bedeutender Unterschied (p < 0,05) der O₂-Aufnahmesteigerung zwischen der Gruppe normaler (155%) und normaler, auf 17°C adaptierter Mäuse (165%) und der Gruppe haarloser Mäuse (195%) festgestellt.     

Polar transport of the plant hormone auxin – the role of PIN-FORMED (PIN) proteins

The PIN-FORMED (PIN) protein family is a group of plant transmembrane proteins with a predicted function as secondary transporters. PINs have been shown to play a rate-limiting role in the catalysis of efflux of the plant growth regulator auxin from cells, and their asymmetrical cellular localization determines the direction of cell-to-cell auxin flow. There is a functional redundancy of PINs and their biochemical activity is regulated at many levels. PINs constitute a flexible network underlying the directional auxin flux (polar auxin transport) which provides cells in any part of the plant body with particular positional and temporal information. Thus, the PIN network, together with downstream auxin signalling system(s), coordinates plant development. This review summarizes recent progress in the elucidation of the role of PIN proteins in polar auxin transport at the cellular level, with emphasis on their structure and evolution and regulation of their function. Received 28 December 2006; received after revision 16 February 2007; accepted 26 March 2007     

Bacterial aging: from mechanistic basis to evolutionary perspective

Aging—defined as the progressive impairment of an organism’s functional capacity, resulting from deleterious changes in cells, organs, and biological systems—is one of the most fundamental features of Eukaryotes, from humans to the unicellular budding yeast Saccharomyces cerevisiae. It has recently been reported that this may also be the case for certain (if not all) types of bacteria. In this paper, the current view on the mechanistic background and evolutionary significance of bacterial kind of aging is presented, with particular emphasis on the role of asymmetric cell division, the characteristics of stationary growth phase, and the role of oxidative protein damage.     

Calcification of the islets of langerhans and renal cortical tubular epithelium in alloxan treated calciphylactic rats

Zusammenfassung Es wird über das Vorkommen der akuten Calcifikation im Bereich der Langerhans'schen Inseln und des renalen Tubularepitheliums mit Alloxan behandelter Ratten während des calciphyllaktischen Zustandes berichtet.

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Presented at the Biological Society on the Palacký University, November 21, 1962.     

Effects of no mating on the female adults and embryonic development of Schistocerca gregaria (Orthoptera: Acrididae)

The newly emerged adult females of Schistocerca gregaria were separated and kept in the rearing conditions without males to examine the detailed developmental characteristic of the no mating females and carefully observed the developmental progress of non-fertilised eggs laid by virgin females. The results showed that the females kept without males survived in average 43 d, i.e. 58% of the life span of mated controls, and laid correspondingly fewer egg pods. The size of egg batches, the weight of eggs, and their content of ecdysteroids were normal but the hatch rate was reduced to 18.27%. Blocks of early embryogenesis (58.43%) and hatching failures (23.29%) were the major causes of death. Moreover, most of the hatched insects died during the postembryonic development and only a few females reached the adult stage. All insects that developed until the penultimate or last larval instar or reached the adult stage were females.     

Increased apoptosis in differentiating p27-deficient mouse embryonic stem cells

In mouse embryonic stem (mES) cells, the expression of p27 is elevated when differentiation is induced. Using mES cells lacking p27 we tested the importance of p27 for the regulation of three critical cellular processes: proliferation, differentiation, and apoptosis. Although cell cycle distribution, DNA synthesis, and the activity of key G1/S-regulating cyclin-dependent kinases remained unaltered in p27-deficient ES cells during retinoic acid-induced differentiation, the amounts of cyclin D2 and D3 in such cells were much lower compared with normal mES cells. The onset of differentiation induces apoptosis in p27-deficient cells, the extent of which can be reduced by artificially increasing the level of cyclin D3. We suggest that the role of p27 in at least some differentiation pathways of mES cells is to prevent apoptosis, and that it is not involved in slowing cell cycle progression. We also propose that the pro-survival function of p27 is realized via regulation of metabolism of D-type cyclin(s).Received 25 February 2004; received after revision 5 April 2004; accepted 15 April 2004