Paleobotanical studies inFagaceae of the European Tertiary

A systematic reassessment of megafossil records ofFagaceae in Central Europe has been undertaken on the basis of leaf cuticular characters. The oldest representatives date back to the Eocene:Quercus subhercynica spec. nova,Dryophyllum furcinerve (Rossm.)Schmalh.,Trigonobalanopsis rhamnoides (Rossm.) gen. & comb. nov. In the Oligocene other members of extant genera appear:Quercus rhenana (Weyl. & Kilpp.)Knobloch & Kvaek,Fagus attenuata Goepp.,Lithocarpus saxonicus spec. nova. In the Neogene these ancient taxa (except inFagus lineage), are gradually replaced by deciduous species ofQuercus andCastanea. Trigonobalanus andCastanopsis are recorded by fruits (or wood) only.     

Biological role of endoreplication in the process of spermatogenesis inChara vulgaris L.

Summary During cell division in antheridial filaments ofChara vulgaris an increase in DNA content occurs in both shield cells and manubria within an antheridium, reaching 16C–64C and 8C–32C levels, respectively. Endoreplication ceases prior to the formation of spermatids and initiation of spermiogenesis, probably as a result of symplasmic isolation of the antheridium from the thallus. As the DNA content of the nuclei increases, the shield cells³H-leucine incorporation increases, and they grow intensively in the tangential plane. Translation decreases considerably after termination of shield cell growth. DNA content of mature manubria is half of that in shield cells, although their size is 10 times that of manubria. Translational activity of manubria also increases as DNA content rises and cells grow. However, during spermiogenesis, this activity remains at its maximum, which is associated with the secretory function of the manubria. Spermiogenesis is also accompanied by far-reaching ultrastructural changes within the manubrial cytoplasm.The level of endopolyploidy in both shield cells and manubria of antheridia formed in the spring is higher by one replication cycle, than in autumnal antheridia. AMO-1618, at a concentration of 10^–5M reduces the DNA content in the autumnal manubria. The higher the manubrial level of endopolyploidy in spermiogenesis, the greater their size, and the higher the translational activity and number of joined spermatids. The number of spermatozoids in the antheridium is also positively correlated with the internal volume of an antheridium, which is itself dependent on the endopolyploidy level of shield cells.The results obtained confirm the assumption that endoreplication favours the higher growth dynamics and potential translational activity, which occurs in the dynamic growth phase only in shield cells, while in manubria, i.e. cells producing substances necessary to spermatozoids development, it remains high until the end of spermiogenesis.     

Certain aspects of so-called post cholecystectomy syndrome

The study involved 126 patients with cholelithiasis. Set of biochemical, radiological, endoscopic, and ultrasound examinations was carried out in these patients. Potential coincidence of clinical symptoms and causes of so-called postcholecystectomy syndrome was the purpose of a 1-year follow-up studies. The significance of the results are discussed.     

Role of Staphylococcus saprophyticus in human infection.

Biological properties of Staphylococcus saprophyticus strains isolated from urinary tract infection and respiratory tract secretions were investigated. The majority of S. saprophyticus strains exhibit moderate surface hydrophobic properties, as measured by Hydrophobic Interaction Chromatography. There was no significant difference between two groups of isolates in respect to electrostatic charge. It was found that the ability to form a diffuse type of growth is characteristic for most of S. saprophyticus strains despite of source of isolation. Five carbohydrates on the surface of 25% of S. saprophyticus strains were shown by means of specific lectin agglutination. Some of the tested strains were capable to bind labelled fibrinogen.     

Streptomycetes excreting dd-carboxypeptidases

Summary Excretion of exocellular dd-carboxypeptidases was tested using 128 strains of streptomycetes. Exocellular enzyme activity was shown in 13% of the trains investigated. Streptomyces strains showed low activity of excretion of dd-carboxypeptidases: 2.7–4.8 M of released C-terminal d-alanine (d-Ala) residue/1 culture supernatant per minute. Saccharopolyspora erythraea mutants produced considerably higher levels of exocellular enzymes, the dynamics of excretion depending upon the medium used. The highest activity of exocellular dd-carboxypeptidase production was 44 M d-Ala/1 culture supernatant per minute. The affinity of exocellular dd-carboxypeptidase of S. erythraea 64-575 for -lactam antibiotics was assessed by a statistical computer programme. The enzyme showed the lowest affinity for sodium cefotaxime, ID₅₀(M) = 7.5 × 10^–6, and the highest for potassium cephalosporin C, ID₅₀(M) = 5.0 × 10^–9, ID₅₀(M) representing the molar concentration of -lactan antibiotics which decreased by 50% the release of d-Ala. Offprint requests to: W. Kurzatkowski     

Planktic coccal and trichal green algae of Lake Volvi,Greece

In the course of three years' investigations (1983–1986) of Lake Volvi, N Greece, 62 species and varieties of chlorococcal algae and 6 species of ulotrichal algae (Chlorophyceae) were found. Although chlorophytes form the largest group of the phytoplankton assemblages of the lake, their biomass is relatively small or even negligeable in some periods of the year in comparison with domination cyanophytes, diatoms and cryptophytes. Morphological variation of diagnostic features is described and documented by original drawings in 53 taxa.     

Nardo-Agrostion communities in the Krkonoše and West Carpathians Mts.

The montaneNardus-rich acidophilous meadows occurring in the Krkono?e and W. Carpathians Mts. were evaluated. They are classified intoNardo-Agrostion tenuis Sillinger 1933. Five associations were distinguished:Sileno-Nardetum, Homogyno-Nardetum, Hieracio Lachenalii-Nardetum, Phleo alpini-Nardetum, andRanunculo nemorosi-Nardetum, the first occuring in the Krkono?e Mts., the others in the W. Carpathians.     

Scanning electron microscopy of cultures of rare macromycetous fungi

Using scanning electron microscopy it was possible to describe structures on the mycelia of macromycetous fungi that possess both taxonomic and functional importance. For taxonomic characteristization of 11 studied species, the presence and distribution of clamps on hyphæ represent an, important feature; in the case ofLyophyllum decastes the form of clamps may be useful for identifying cultures. Formation and types of anamorhps inPleurotus calyptratus, Montagnea arenaria andLyophyllum decastes are also of taxonomic importance. For additional taxonomic characterization of cultures ofTricholoma mongolicum the formation of “coils” might be exploited. Formation of anastomoses and crystals has predominantly a physiological role. However, in our view, production of crystals under certain culture conditions may serve as a diagnostic parameter.     

Three fluorescent probes for the flow-cytometric assessment of membrane potential inSaccharomyces cerevisiœ

Three fluorescent probes, tetramethyl rhodamine ethyl ester (TMRE), 3,3′-dipropylthiacarbocyanine iodide (diS-C₃(3)) and 3,3′-dipropyloxacarbocyanine iodide (diO-C₃(3)), were tested for their suitability as fluorescent indicators of membrane potential inSaccharomyces cerevisiœ in studies performed by flow cytometry. For all these dyes the intensity of fluorescence of stained cells increased with probe concentration in the range of 60–3000 nmol/L. The optimum staining period was 15–20 min for diS-C₃(3). Depolarization of cells by increased extracellular potassium level and by valinomycin elicited with all probes a drop in fluorescence intensity. In some yeast batches this depolarization was accompanied by a separation of subpopulations with different fluorescence properties.     

Cardiac phosphocreatine deficiency induced by GPA during postnatal development in rat

The effect of chronic administration of -guanidinopropionic acid (GPA) on the protein profiling, energy metabolism and right ventricular (RV) function was studied in the rat heart during the weaning and adolescence period. GPA was given in tap water (1–1.5%) using pair drink controls. The feeding of animals with GPA solution for a six week period resulted in elevation of heart to body weight ratio due to body growth retardation. GPA accumulated in the myocardium up to 67.37 ± 5.3 moles.g dry weight and the tissue content of total creatine, phosphocreatine and ATP was significantly decreased to 15%, 9% and 65% of control values respectively. Total activity of creatine kinase (CK) was not changed, but the proportion of mitochondrial (Mi) CK isoenzyme was decreased; the percentage of MB isoenzyme of CK was significantly higher. GPA treatment resulted in an elevation of the content of cardiac collagenous proteins and decrease of non-collagenous proteins in the heart; in parallel, a decrease of the collagen I to collagen III ratio was detected. The function of the RV was assessed using an isolated perfused heart with RV performing pressure-volume work. As compared to pair-drink controls, RV function was significantly impaired the GPA group: at any given right atrial filling pressure, the RV systolic pressure and the rate of pressure development were decreased by almost a factor of two. Elevation of the RV diastolic pressure with increasing pulmonary artery diastolic pressure was also significantly steeper in the GPA group which also showed decrease of cardiac output, especially at high outflow resistance. It may be assumed that chronic administration of GPA deeply influenced metabolic parameters, protein profiles and contractile function of the developing heart. On the other hand, concentrations of glucose, total lipids and triglycerides in blood plasma were not affected. All these data confirm the concept that the CK system is of central importance both for heart function and for the regulation of normal growth of cardiac myocytes.