Two new species and one variety of nitrate-utilizing mycelial Candida isolated from decayed wood in the evergreen rainy Valdivian forest of southern Chile

Two unusual species of Candida and one variety of one of them, isolated from decayed wood (palo podrido) (12) in the ultimate stages of degradation, are described and illustrated. They differ sufficiently from all accepted Candida species to warrant their establishment as two new species and one variety: Candida railenensis, Candida bertae, and Candida bertae var. chiloensis.The DNA base composition of these yeasts was not calculated, since our laboratory is not properly equipped for that purpose.     

Induction of lordosis behavior in female rats by intravenous administration of progestins

Progesterone is rapidly metabolized by neural cells in the rat. Progesterone could, therefore, act as a “prohormone,” stimulating lordosis behavior in estrogen-primed rats only after metabolic conversion. Were such the case, one might expect one or more of the naturally occurring metabolites of progesterone to be more potent than the parent compound. Estradiol benzoate-primed rats were therefore administered intravenously 200 μg of progesterone or one of five immediate metabolites of progesterone. The steroid 20α-dihydroprogesterone was found to be more potent than progesterone. Both 20α-hydroxy-5α-pregnan-3-one and 3α-hydroxy-5α-pregnan-20-one were less potent than progesterone, but more potent than the vehicle propylene glycol. Neither 5α-pregnane-3α, 20α-diol nor 5α-pregnane-3,20-dione (dihydroprogesterone, DHP) differed from the vehicle in potency. The data suggest that 20α-dihydroprogesterone, which is secreted at high levels during the estrous cycle, could play a role in the regulation of sexual receptivity. The data also suggest that 5α-reduction is probably not crucial for progesterone's action.     

Concept of energy in biological systems and the effects of irradiations of low energies on enzyme-substrate systems

The recent mathematical formalization of the concepts of matter and extrinsical energy, which are used for the relational representation of biological systems, is employed in the analysis of the important experimental discoveries of Comorosanet al. related to low energy electromagnetic irradiations on enzyme substrates. By means of the present analysis one of the properties inherent to the experimental phenomena is more precisely exposed, and theoretical developments corresponding to “energetical evolutions” in a biological system (Leguizamón, 1976) may now have an experimental basis. Important limitations are introduced for the validity of the commutativity and associativity of cartesian product of sets, when they represent matter and its linked extrinsical energy. In connection with this last aspect, new important knowledge is obtained for the relational mathematical representation of biological systems.     

A new composite xenograft monocusp patch for reconstruction of the right ventricular outflow tract: A preliminary report

Pulmonary insufficiency secondary to outflow tract reconstruction remains an unsolved problem. Although a number of surgical techniques have been designed to avoid or palliate this condition, none so far has been satisfactory. This report describes a new composite stented porcine monocusp patch, which, because of its desirable hemodynamic characteristics, promises to yield stable and reproducible results. The clinical effectiveness of the patch is documented by its successful application in a patient with tetralogy of Fallot.     

The interaction of phenylglyoxal with soluble and membrane-bound chloroplast coupling factor 1

The rate of inhibition of cyclic photophosphorylation in chloroplast thylakoids by the arginine reagent phenylglyoxal was enhanced in the light, i.e., under conditions where membrane energization occurred. Uncouplers, but not energy-transfer inhibitors, prevented the effect of light. Chemical modification of chloroplast thylakoids by phenylglyoxal under dark or in light conditions affected differently the light-induced exchange of tightly bound ADP. In both cases the exchange was less inhibited than photophosphorylation. Complete inhibition of ATPase activity of soluble CF₁ was correlated with the incorporation of 8 mol [¹⁴C]phenylglyoxal per mol enzyme. About 50% of the incorporated radioactivity was lost at different rates depending on the buffer present and suggesting a change in the stoichiometry of the adduct from 2:1 to 1:1. Inhibition of ATPase and photophosphorylating activities of chloroplasts by modification with [¹⁴C]phenylglyoxal in the dark was associated with the incorporation of 1 and 2 mol reagent per mol membrane-bound CF₁, respectively. In the light the rate of incorporation was enhanced and both reactions were inactivated when 2 mol $\text{[}{}^{14}\text{C]phenylglyoxal}\text{CF}{}_1$ were bound. In all the labelling experiments the radioactivity was mainly recovered from the α- and β-subunits.     

Studies on the adenosine 3′,5′-monophosphate-dependent protein kinase of Blastocladiella emersonii

Using a combination of Chromatographic and sucrose density gradient techniques under carefully controlled conditions of pH and protease inhibitors, we demonstrate that there is only one form of adenosine 3′,5′-monophosphate-dependent protein kinase in the cytosol fraction of the Blastocladiella emersonii zoospore. If any of these conditions are omitted during extract preparation, one obtains what are apparently multiple forms of the enzyme, which are in reality artifacts due to extensive endogenous proteolytic activity. This endogenous protease is stimulated by alkaline pH and inhibited by antipain. The zoospore protein kinase is similar to type II protein kinase from mammalian cells in several aspects including Chromatographic behavior on DEAE-cellulose column, conditions for subunit dissociation and reassociation, as well as the molecular weight value of the regulatory subunit.     

Burrowing beetles of the genus Bledius (Staphylinidae) as agents of bioturbation in the emergent areas and shores of an athalassic inland lake (Fuente de Piedra,southern of Spain)

Bledius (Elbidus) bicornis (Germ.) and B. (Eucerotobledius) furcatus (Oliv.) (Coleoptera: Staphylinidae) are the most important burrowing species in the emergent areas and shores in the athalassic lake of Fuente de Piedra (Málaga, S. of Spain). A first estimate of the importance of these organisms in this system is presented. These insects kick out sediment during their burrowing activity, which accumulates on the surface near the burrows as tumuli which can be easily eroded. The lake perimeter (17 km) is densely colonized (usual densities from 1700 to 2500 ind m⁻²). The amount of granulated material that can be potentially kicked out was 46.22 g dry wt m⁻² day⁻¹. At the same time, the material that constitutes the tumuli shows different characteristics from the compact ground below the surface. Thus, it is relatively enriched with organic matter (6.15 g per square meter), soluble phosphate (406.5 μg m⁻²) and ammonium (4856 μg m⁻²), whereas it lacks nitrate. Results of a transect from uninhabited areas to zones of maximum population density also show a similarity between the higher ground level of ammonium and phosphate concentrations and population density.     

Influence of temperature and salinity on carbon and nitrogen content in Dunaliella viridis teodoresco under nitrogen sufficiency

Cell carbon and nitrogen in D. viridis are strongly dependent on the culturing conditions. Both elements increase with increasing salinity. At 31°C cell carbon is maximum and cell nitrogen minimum. This temperature was described previously (Jiménez, C., Niell, F. X. & Fernandez, J. A. (1990). Hydrobiologia, 197, 165-72) as the optimal one for achieving the maximum oxygen evolution. These results point out a possible competence for the reducing power during carbon and nitrogen assimilation processes, and under conditions of high photosynthesis (carbon assimilation) there is a partial inhibition of nitrate reduction, making C:N ratio maximum under conditions of maximum net photosynthesis.The study of cell glycerol, nitrate, structural proteins and free amino acids indicates that all of these solutes accumulate in the cells as a result of the high salinity adaptation.