On the specificity of the in vitro and in vivo antifungal activity of benomyl

With respect to sensitivity to benomyl in vitro four categories of fungi were distinguished; taxonomically related fungi usually proved to belong to the same category. Within the form-class Deuteromycetes a correlation appeared to exist between sensitivity to this fungicide and morphogenesis of conidia.Phoma betae, in contrast to all otherPhoma spp., was shown to be highly resistant to benomyl. This, however, may be expected on account of its perfect state. The data on the in vitro antifungal activity of benomyl conformed to those on the effectiveness of benomyl against plant diseases.     

Syntheseaktivität und Grösse der Zellkerne von Phaseolus vulgaris nach Infektion mit Uromyces phaseoli typica

Zusammenfassung In rostinfizierten Bohnenblättern werden acht Tage nach der Infektion¹⁴C-Orotsäure und³H-Uridin in die Zellkerne von Wirt und Parasit eingebaut, wobei relativ hohe Aktivität in den Wirtskernen unter der Pustel gefunden wird. Vorbehandlungen mit Actinomycin D verhindert diesen Einbau zum grössten Teil. Die Durchmesser der Wirtskerne sind im Pustelbereich klein und nehmen nach aussen stetig zu; die Nucleolen sind dagegen im Bereich der Pusteln ebenso gross wie in 750–1000 Abstand vom Pustelrand, und im dazwischen liegenden Bereich kleiner. Unter den Pusteln vonUromyces phaseoli typica treten in grösserem Umfang Mitosen auf; die relative Zahl nimmt vom Pustelkern aus gegen das ungestörte Gewebe zu ab. Die Ergebnisse werden im Blick auf verschiedene Typen der Wirt-Parasit-Beziehung diskutiert.Orotic acid-¹⁴C and uridine-³H was applied to floating discs of tissue from main leaflets ofPhaseolus vulgaris infected withUromyces phaseoli. Label appeared not only in the nuclei of the host cells but also in the nuclei of actively growing hyphae of the rust, as shown by Tschen (1966). The label is accumulated by DNA-dependent RNA synthesis. Pretreatment with actinomycin D limits labelling to about 10%. The label is destroyed by treating the tissue with RNAse, not with DNAse.In sections of host tissues near the rust pustule, the activity was higher in host nuclei near the pustule. In this region there were many dividing nuclei. The nuclei are smaller directly below the pustule than in zones of tissue further away from the centre of infection. Cell divisions are most frequent on the 7th to 8th day after inoculation.The results contrast with those on wheat with rust and are considered as a stimulation of the host tissue in a progressed stage of host-parasite relationship; it depends on the density of infection. The results are consistent with observations of Yarwood and Cohen (1950) on hypertrophy of bean leaves with rust.Samenvatting Met orotzuur-¹⁴C, toegediend aan drijvende schijfjes van primaire bladeren vanPhaseolus vulgaris geïnoculeerd metUromyces phaseoli, is het niet slechts mogelijk de kernen van de waardplant te merken, maar zoals aangetoond door Tschen (1966) ook die van de actief groeiende hyphen van de roest.¹⁴C-accumulatie vindt plaats door van DNA afhankelijke RNA-synthese. Voorbehandeling met actinomycine D voorkomt de inbouw van¹⁴C voor ongeveer 90%. De substitutie wordt teniet gedaan door behandeling van het weefsel met RNAse, niet met DNAse.Coupes van het waardplantweefsel onder en rond het roest-sporehoopje geven een grotere activiteit in de waardplantkernen te zien dichtbij het sporehoopje. In deze omgeving zijn vele delende kernen te zien. Onder het sporehoopje zijn de kernen kleiner dan in de weefselgedeelten die verder van het infectiecentrum zijn verwijderd. Celdelingen vinden het meest plaats 7–8 dagen na de inoculatie.De resultaten, strijdig met waarnemingen aan door roest aangetaste tarwe, worden beschouwd als een activering van het waardplantweefsel in een vergevorderd stadium van de waardplant-parasiet-relatie, afhankelijk van de mate van infectie. Deze resultaten stemmen overeen met waarnemingen van Yarwood en Cohen (1950) betreffende hypertrofie bij door roest aangetaste bonebladeren.     

Use of Cholesterol‐Loaded Cyclodextrin in Donkey Semen Cryopreservation Improves Sperm Viability but Results in Low Fertility in Mares

The use of cholesterol‐loaded cyclodextrin (CLC) on semen cryopreservation has been related with better sperm viability in several species; however, the effect on fertility is not known in donkey semen. Ejaculates (n = 25) from five donkeys were diluted in S‐MEDIUM with 0, 1, 2 or 3 mg of CLC/120 × 10⁶ spermatozoa. Semen was frozen, and thawed samples were evaluated by computer‐assisted sperm analyser system (CASA), supravital test, hyposmotic swelling test and fluorescent dyes to assess the integrity of sperm membranes. Mares (n = 60) were inseminated with frozen‐thawed semen treated with the doses of 0 or 1 mg CLC. Percentages of sperm with progressive motility and with functional plasma membrane were greater (p < 0.05) in the CLC‐treated groups than in the control. Percentages of intact plasma membrane and intact plasma membrane and acrosome detected by fluorescent dyes were also greater (p < 0.05) in CLC‐treated groups. Although no difference (p > 0.05) in conception rates was detected between groups (control, 3/30, 10%; CLC‐treated, 1/30, 3.3%), fertility was low for artificial insemination programs in mares. Therefore, we firstly demonstrated that frozen semen treated with CLC in S‐MEDIA extender before freezing improves the in vitro sperm viability, but semen treated or not with CLC in S‐MEDIUM extender results in a very low conception rate in mares inseminated with thawed donkey semen.     

Linear alkane polymerization on a gold surface

In contrast to the many methods of selectively coupling olefins, few protocols catenate saturated hydrocarbons in a predictable manner. We report here the highly selective carbon-hydrogen (C-H) activation and subsequent dehydrogenative C-C coupling reaction of long-chain (>C(20)) linear alkanes on an anisotropic gold(110) surface, which undergoes an appropriate reconstruction by adsorption of the molecules and subsequent mild annealing, resulting in nanometer-sized channels (1.22 nanometers in width). Owing to the orientational constraint of the reactant molecules in these one-dimensional channels, the reaction takes place exclusively at specific sites (terminal CH(3) or penultimate CH(2) groups) in the chains at intermediate temperatures (420 to 470 kelvin) and selects for aliphatic over aromatic C-H activation.     

PDZ domain binding selectivity is optimized across the mouse proteome

PDZ domains have long been thought to cluster into discrete functional classes defined by their peptide-binding preferences. We used protein microarrays and quantitative fluorescence polarization to characterize the binding selectivity of 157 mouse PDZ domains with respect to 217 genome-encoded peptides. We then trained a multidomain selectivity model to predict PDZ domain-peptide interactions across the mouse proteome with an accuracy that exceeds many large-scale, experimental investigations of protein-protein interactions. Contrary to the current paradigm, PDZ domains do not fall into discrete classes; instead, they are evenly distributed throughout selectivity space, which suggests that they have been optimized across the proteome to minimize cross-reactivity. We predict that focusing on families of interaction domains, which facilitates the integration of experimentation and modeling, will play an increasingly important role in future investigations of protein function.     

Cholinergic synaptic inhibition of inner hair cells in the neonatal mammalian cochlea

Efferent feedback onto sensory organs provides a means to modulate input to the central nervous system. In the developing mammalian cochlea, inner hair cells are transiently innervated by efferent fibers, even before sensory function begins. Here, we show that neonatal inner hair cells are inhibited by cholinergic synaptic input before the onset of hearing. The synaptic currents, as well as the inner hair cell's response to acetylcholine, are mediated by a nicotinic (alpha9-containing) receptor and result in the activation of small-conductance calcium-dependent potassium channels.     

Orthopyroxene-plagioclase fragments in the lunar soil from apollo 12

Rock fragments consisting of orthopyroxene-calcic plagioclase assemblages appear to be more common in Apollo 12 soil samples than in the breccias or soil from Apollo 11 and are mineralogically and chemically different from any of the crystalline rocks returned by either Apollo 11 or Apollo 12. Compositionally, these fragments are orthopyroxenites and feldspathic orthopyroxenites. They are probably not fragments of meteorites; other considerations point to a near-surface lunar origin.     

A role for skin gammadelta T cells in wound repair

Gammadelta T cell receptor-bearing dendritic epidermal T cells (DETCs) found in murine skin recognize antigen expressed by damaged or stressed keratinocytes. Activated DETCs produce keratinocyte growth factors (KGFs) and chemokines, raising the possibility that DETCs play a role in tissue repair. We performed wound healing studies and found defects in keratinocyte proliferation and tissue reepithelialization in the absence of wild-type DETCs. In vitro skin organ culture studies demonstrated that adding DETCs or recombinant KGF restored normal wound healing in gammadelta DETC-deficient skin. We propose that DETCs recognize antigen expressed by injured keratinocytes and produce factors that directly affect wound repair.