Supraspecific division of the genusJuncus (Juncaceae)

A new classification of the genusJuncus (Juncaceae) is presented. The genus is divided into two subgenera, characterized by the presence/absence of bracteoles and the structure of inflorescence. Lower rank subdivisions, sections, generally correspond to the traditionally recognized subgenera introduced by Buchenau. A new name is introduced for what has been called subg. (sect.)Ensifolii, Juncus sect.Iridifolii. A checklist of supraspecific names inJuncus, with typification and references to the sectional names accepted, is presented in the Appendix.     

Geastrum sessile (Sow.) Pouz., the correct name forGeastrum fimbriatum Fr. (Gasteromycetes)

The author discusses the nomenclature of the speciesGeastrum fimbriatum Fr.; shows why it is not possible to apply the nameGeastrum rufescens Pers. exPers. to this species and maintains the use of the nameGeastrum sessile (Sow.)Pouz., which is here proposed as a new combination.     

Inhibition of mitochondrial ATPase by dicarbopolyborate,a new enzyme inhibitor

Polyborate anions were found to inhibit mitochondrial ATPase. Mercapto and chloro derivatives of dicarbononaborates showed full inhibition of the enzyme activity at 0.5–0.8 mM. The inhibitory effect of dodecaborates was lower. The inhibition was of competitive type with respect to ATP. The inhibition of soluble F₁-ATPase indicates a direct interaction of the polyborate anion with the catalytic part of the enzyme molecule.     

Changes in GM1 ganglioside content and localization in cholestatic rat liver

(Glyco)sphingolipids (GSL) are believed to protect the cell against harmful environmental factors by increasing the rigidity of plasma membrane. Marked decrease of membrane fluidity in cholestatic hepatocytes was described but the role of GSL therein has not been investigated so far. In this study, localization in hepatocytes of a representative of GSL, the GM1 ganglioside, was compared between of rats with cholestasis induced by 17α-ethinylestradiol (EE) and vehicle propanediol treated or untreated animals. GM1 was monitored by histochemical reaction employing cholera toxin B-subunit. Our findings in normal rat liver tissue showed that GM1 was localized in sinusoidal and canalicular hepatocyte membranes in both peripheral and intermediate zones of the hepatic lobules, and was nearly absent in central zones. On the contrary, in EE-treated animals GM1 was also expressed in central lobular zones. Moreover, detailed densitometry analysis at high magnification showed greater difference of GM1 expression between sinusoidal surface areas and areas of adjacent cytoplasm, caused as well by increased sinusoidal staining in central lobular zone as by decreased staining in cytoplasm in peripheral zone. These differences correlated with serum bile acids as documented by linear regression analyses. Both GM1 content and mRNA corresponding to GM1-synthase remained unchanged in livers; the enhanced expression of GM1 at sinusoidal membrane thus seems to be due to re-distribution of cellular GM1 at limited biosynthesis and could be responsible for protection of hepatocytes against harmful effects of bile acids accumulated during cholestasis.     

Gold(I) Complexes of 9-Deazahypoxanthine as Selective Antitumor and Anti-Inflammatory Agents

The gold(I) mixed-ligand complexes involving O-substituted derivatives of 9-deazahypoxanthine (HL_n) and triphenylphosphine (PPh₃) with the general formula [Au(L_n)(PPh₃)] (1–5) were prepared and thoroughly characterized by elemental analysis, FT-IR and multinuclear NMR spectroscopy, ESI+ mass spectrometry, single crystal X-ray (HL₅ and complex 2) and TG/DTA analyses. Complexes 1–5 were evaluated for their in vitro antitumor activity against nine human cancer lines, i.e. MCF7 (breast carcinoma), HOS (osteosarcoma), A549 (adenocarcinoma), G361 (melanoma), HeLa (cervical cancer), A2780 (ovarian carcinoma), A2780R (ovarian carcinoma resistant to cisplatin), 22Rv1 (prostate cancer) and THP-1 (monocytic leukaemia), for their in vitro anti-inflammatory activity using a model of LPS-activated macrophages, and for their in vivo antiedematous activity by λ-carrageenan-induced hind paw edema model on rats. The results showed that the complexes 1–5 exhibit selective in vitro cytotoxicity against MCF7, HOS, 22Rv1, A2780 and A2780R, with submicromolar IC₅₀ values for 2 against the MCF7 (0.6 µM) and HOS (0.9 µM). The results of in vitro cytotoxicity screening on primary culture of human hepatocytes (HEP220) revealed up to 30-times lower toxicity of compounds against healthy cells as compared with cancer cells. Additionally, the complexes 1–5 significantly influence the secretion and expression of pro-inflammatory cytokines TNF-α and IL-1β by a similar manner as a commercially used anti-arthritic drug Auranofin. The tested complexes also significantly influence the rate and overall volume of the edema, caused by the intraplantar application of λ-carrageenan polysaccharide to rats. Based on these promising results, the presented compounds could qualify to become feasible candidates for advanced testing as potential antitumor and anti-inflammatory drug-like compounds.     

Histochemical demonstration of enterokinase

Summary A new simple method for the histochemical demonstration of enterokinase (enteropeptidase, EC 3.4.4.8) was elaborated. Unfixed cold microtome sections adherent to the slides are covered with agar-gel medium containing trypsinogen (0.5–1 mg per 1 ml), N-benzoyl-DL-arginine--naphthylamide hydrochloride (2–4 mM), and Fast Blue B Salt (0.5 mg per 1 ml) in 0.05 M Tris maleate buffer pH 6.5 with 0.05% CaCl₂. After the incubation in a wet chamber at 37° C the slides are chelated in 2% copper sulphate. The method enables a localization on the histological level. The evaluation of the overall staining obtained with this method in sections of the duodenum, jejunum and ileum of guinea pigs, rats, monkeys, dogs and humans reflects well the biochemical quantitative data on enterokinase activity obtained in homogenates of mucosal scrapings of the corresponding gut segments of the same animals.In all animals a proximodistal gradient was found. The highest activities were found in enterocytes covering apical parts of villi in the duodenum. According to the activities in the duodenum the investigated animals can be arranged in the following series: guinea pig (highest activity), monkey, man, rat and dog.