Regulation of cyclic GMP binding to retinal rod membranes by calcium

The apparently cooperative binding of 8-(5-thioacetamidofluorescein)-cGMP (SAF-cGMP) to cGMP-binding sites of the rod outer segments is regulated by Ca2+ in the 0.1-1 microM activity range. High Ca2+ reduces, and low Ca2+ increases the affinity of SAF-cGMP binding. This regulation involves only intrinsic membrane components. It is proposed that an allosteric regulation of cGMP binding by Ca2+ can contribute to photoreceptor potential adaptation.     

Keratinophilic fungi isolated from the air at Pavia

The presence of keratinophilic fungi was revealed by sampling the air of Pavia (Italy) from March 1981 to February 1982. The species isolated were: Chrysosporium indicum, Geomyces pannorum var.pannorum, Microsporum gypseum, Myceliophtora vellerea and Trichophyton terrestre. Several filamentous fungi tolerating high levels of cycloheximide were also recovered.     

Coprophilous fungi of the horse

A total of 1267 microfungi, including 35 Myxomycetes, were recorded from the fecal samples of the 60 horses; of these 395 were found on 20 saddle-horse feces, 363 on 20 race-horses and 509 on 20 working-horses. Eighty two species representing 53 genera were recorded; of these 7 were Zygomycetes, 18 Ascomycetes, 1 Basidiomycetes and 25 Fungi Imperfecti: 2 Myxomycetes. Common coprophilous fungi are in decreasing orderPilobolus kleinii, Saccobolus depauperatus, Mucor hiemalis, Lasiobolus ciliatus, Podospora curvula, Petriella guttulata, M. circinelloides, Coprinus radiatus, Dictyostelium mucoroides, Sordaria fimicola, C. miser, C. stercorarius, Acremonium sp., Coprotus granuliformis, Graphium putredinis, Iodophanus carneus, Chaetomium murorum, Podospora communis, P. inaequalis, P. setosa, Saccobolus versicolor andCladosporium cucumerinum. Species ofMyrothecium verrucaria, Actinomucor elegans, Kernia nitida, Spiculostilbella dendritica andMucorparvispora were found exclusively in working-horses feces.Badhamia sp., Anixiopsis stercoraria, Echinobotryum state ofD. stemonitis, Geotrichum candidum andOidiodendron sp. were found only in saddle-horses feces.Chlamidomyces palmarum andPhilocopra sp. were found exclusively in race-horses feces.Notes on infrequent or interesting fungi includeThamnostylum piriforme, Phialocephala dimorphospora, Rhopalomyces elegans andSpiculostilbella dendritica.     

Superficial mycoses in Italy

A total of 1244 cases suspected of superficial mycoses were analysed in a period of 12 months in Italy. Dermatophytoses were found in 62.4%; the other common disease was Pityriasis versicolor (44.1%). The predominant speciesEpidermophyton floccosum (34,2%) was strickingly high in relation to other statistics; this species was commonest in tinea cruris. Among the other dermatophytesM. canis was predominant (31.3%) commonest in tinea corporis, followed byT. mentagrophytes (17,8%) andT. rubrum (10,3%). A high rate of yeasts was found in tinea manum (81.6%) and tinea pedis (47.7%).     

Some Filamentous Fungi on Grassland Vegetation from Kenya

Herbaceous plants endemic to native Kenyan grassland on the Marula Estate were assessed for their phylloplane fungal occurrence using leaf cultures on tap water agar. From 26 sampled plants, 261 fungal isolates representative of 58 genera and 92 taxa were identified. The principal filamentous fungi were of the genera: Alternaria, Bipolaris, Curvularia, Epicoccum, Fusarium, Nigrospora, Periconia, Phoma and Pithomyces. The fungal species that occurred most frequently were: Alternaria alternata aggreate (73%), Pithomyces chartarum (73%) Nigrospora sphaerica (42%), Torula herbarum (30%) and Microsphaeropsis olivacea (27%). Fungi of limited occurrence were: Didymosphaeria oblitescens, Doliomyces mysoriensis, Endophragmiella dimorphospora, Parapericonia angusii, Podospora minicaudata, Spegazzinia tessarthra, Sporormiella minima, Stagonospora vitensis, Stigmella effigurata and Truncatella conorum-piceae. It is postulated that the phylloplane of these endemic plants provides a niche for endemic fungi. This revised version was published online in June 2006 with corrections to the Cover Date.     

Serotonin and Noradrenaline Reuptake Inhibitors Improve Micturition Control in Mice

Poor micturition control may cause profound distress, because proper voiding is mandatory for an active social life. Micturition results from the subtle interplay of central and peripheral components. It involves the coordination of autonomic and neuromuscular activity at the brainstem level, under the executive control of the prefrontal cortex. We tested the hypothesis that administration of molecules acting as reuptake inhibitors of serotonin, noradrenaline or both may exert a strong effect on the control of urine release, in a mouse model of overactive bladder. Mice were injected with cyclophosphamide (40 mg/kg), to increase micturition acts. Mice were then given one of four molecules: the serotonin reuptake inhibitor imipramine, its metabolite desipramine that acts on noradrenaline reuptake, the serotonin and noradrenaline reuptake inhibitor duloxetine or its active metabolite 4-hydroxy-duloxetine. Cyclophosphamide increased urine release without inducing overt toxicity or inflammation, except for increase in urothelium thickness. All the antidepressants were able to decrease the cyclophosphamide effects, as apparent from longer latency to the first micturition act, decreased number of urine spots and volume of released urine. These results suggest that serotonin and noradrenaline reuptake inhibitors exert a strong and effective modulatory effect on the control of urine release and prompt to additional studies on their central effects on brain areas involved in the social and behavioral control of micturition.     

Diltiazem at high concentration increases the ionic permeability of biological membranes

Summary The effects of diltiazem, a drug which inhibits the calcium channels in cardiac muscle as well as the light-sensitive channels in photoreceptor cells, were studied on ionic fluxes in both membrane and intact cell preparations. Diltiazem nonselectively increased the ionic permeability to both anions and cations in photoreceptor rod outer segment and synaptic membrane vesicles as well as in intact erythrocytes. Under our conditions, the estimated threshold for the diltiazem effect varied between 12.5 and 200 m. In each case the concentration dependence exhibited the sigmoidal shape characteristic of positive cooperativity. The effect of diltiazem on ionic fluxes from phospholipid vesicles were strongly influenced by phospholipid composition and membrane charge. By contrast, diltiazem inhibited the efflux of⁸⁶Rb from photoreceptor cells of intact aspartate-isolated retina, an effect opposite to that of diltiazem on ionic permeabilities in photoreceptor membrane vesicle preparations.These data raise serious doubts on the specificity of diltiazem as a calcium channel blocker or as a cGMP channel blocker when used at concentrations higher than 10 m.     

Protein-bound male urinary pheromones: differential responses according to age and gender

The attractive properties of male urinary pheromones were tested on adult or prepubertal male and female mice. An androgen-dependent protein is present in adult male urine (major urinary protein, MUP) which has been suggested to be a pheromone-binding protein. We tested the pheromonal properties of the protein-bound volatiles in a test of attractiveness. These molecules, that co-purify with MUP, attract females and repel adult males. In prepubertal animals, females are repelled and males are attracted by the same stimuli. These results are similar to those obtained by others with adult male whole urine. Therefore MUP binds molecules with a pheromonal activity, and these molecules are sufficient to act as male signals.      

Some coprophilous fungi from Kenya

The occurrence of coprophilous fungi on samples of antelope, buffalo, zebra and hippopotamus dung collected from the Marula Estates in Kenya was recorded. A hundred and seventy three fungal isolates representative of 40 genera and 59 species were identified. Among these species, 23 were Ascomycetes (39%), 30 Deuteromycetes (50.8%), 5 Zygomycetes (8.5%) and 1 Basidiomycete (1.7%). Ascobolus immersus, Coprotus niveus, Iodophanus carneus, Lasiobolus lasioboloides, Podospora anserina, P. australis and Sporormiella minima were the dominant species occurring in the dung of these animals. Notes on infrequent or interesting Ascomycetes include Kernia nitida, Saccobolus versicolor, Sordaria fimicola and others. The interdependence of the vegetation of this area with the fungi occurring on the dung of these animals is discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Epidemiology of allergic disease: the fungi

Summary In indoor aerial environments and in particular that of homes, the number and type of fungal spores present in the air depend, more than on air exchange with the outside atmosphere, on the presence of sources or dispersion within the building itself. The concentration of spores is half that normally recorded outside the building, withAspergillus, Penicillium, Cladosporium, Alternaria, Mucor, Rhizopus andOidiodendron as the dominating genera. Aerosporological investigations carried out in homes should ideally be done at night, with the exposition of cultural dishes. The repetitive isolation of the same fungus may be particularly important in the etiology of allergic manifestation in man. Particular environments, if insufficiently aerated, with high levels of relative humidity and insufficient illumination, may become ecological niches particularly well suited to fungi, both during its latent form or during a phase of rapid development. Together with rapidly developing fungi, for instanceMucor andRhizopus, slow developing moulds such asPenicillium, Aspergillus andTrichoderma may also be found, characterized however by a production of a great number of easily dispersed conidia. Etiological research into the allergic manifestations of patients continuously inhaling spores responsible for particular allergies appears to be insufficiently developed.