Novel aliphatic epoxide hydrolase activities from dematiaceous fungi

Abstract Epoxide hydrolases were found to be constitutively expressed in dematiaceous fungi coincident with secondary metabolite pigment production in stationary or idiophase. Washed-cell preparations of two fungi, Ulodadium atrum CMC 3280 and Zopfiella karachiensis CMC 3284, exhibited affinity for 2,2-dialkylated oxiranes, for which contrasting enantioselectivities were observed, but not for aromatic styrene oxide or alicyclic cyclohexene oxide type substrates. Lyophilised preparations of soluble epoxide hydrolase activities proved to be effective catalysts for the mild hydrolysis of aliphatic epoxides.     

Effect of thermal tachypnoea and of its mechanical or pharmacological inhibition on hypothalamic temperature in the sheep

The abrupt inhibition of breathing in the panting sheep, by mechanical blockage of the nostrils or by the injection of noradrenaline or carbachol into a lateral cerebral ventricle, causes an immediate rise in hypothalamic temperature, followed by a rise in that of the carotid artery blood.

This confirms that evaporation from the surfaces of the upper respiratory tract has an immediate and local effect on brain temperature.

The significance of this relation in a species which controls its core temperature particularly well is discussed.     

Stepping into the past to conserve the future: Archived skin swabs from extant and extirpated populations inform genetic management of an endangered amphibian

Moving animals on a landscape through translocations and reintroductions is an important management tool used in the recovery of endangered species, particularly for the maintenance of population genetic diversity and structure. Management of imperiled amphibian species rely heavily on translocations and reintroductions, especially for species that have been brought to the brink of extinction by habitat loss, introduced species, and disease. One striking example of amphibian declines and associated management efforts is in California's Sequoia and Kings Canyon National Parks with the mountain yellow‐legged frog species complex (Rana sierrae/muscosa). Mountain yellow‐legged frogs have been extirpated from more than 93% of their historic range, and limited knowledge of their population genetics has made long‐term conservation planning difficult. To address this, we used 598 archived skin swabs from both extant and extirpated populations across 48 lake basins to generate a robust Illumina‐based nuclear amplicon data set. We found that samples grouped into three main genetic clusters, concordant with watershed boundaries. We also found evidence for historical gene flow across watershed boundaries with a north‐to‐south axis of migration. Finally, our results indicate that genetic diversity is not significantly different between populations with different disease histories. Our study offers specific management recommendations for imperiled mountain yellow‐legged frogs and, more broadly, provides a population genetic framework for leveraging minimally invasive samples for the conservation of threatened species.     

Non-anatomical placement adversely affects the functional performance of the meniscal implant: a finite element study

Biomechanics and Modeling in Mechanobiology - Non-anatomical placement may occur during the surgical implantation of the meniscal implant, and its influence on the resulting biomechanics of the...     

Transneuronal Dpr12/DIP‐δ interactions facilitate compartmentalized dopaminergic innervation of Drosophila mushroom body axons

The mechanisms controlling wiring of neuronal networks are not completely understood. The stereotypic architecture of the Drosophila mushroom body (MB) offers a unique system to study circuit assembly. The adult medial MB γ‐lobe is comprised of a long bundle of axons that wire with specific modulatory and output neurons in a tiled manner, defining five distinct zones. We found that the immunoglobulin superfamily protein Dpr12 is cell‐autonomously required in γ‐neurons for their developmental regrowth into the distal γ4/5 zones, where both Dpr12 and its interacting protein, DIP‐δ, are enriched. DIP‐δ functions in a subset of dopaminergic neurons that wire with γ‐neurons within the γ4/5 zone. During metamorphosis, these dopaminergic projections arrive to the γ4/5 zone prior to γ‐axons, suggesting that γ‐axons extend through a prepatterned region. Thus, Dpr12/DIP‐δ transneuronal interaction is required for γ4/5 zone formation. Our study sheds light onto molecular and cellular mechanisms underlying circuit formation within subcellular resolution.     

Localized activity of Ca2+-stimulated ATPase and transcellular ionic currents during mesoderm induction in embryos ofLymnaea stagnalis (Mollusca)

Summary InLymnaea stagnalis, mesoderm induction occurs at the 24-cell stage, when the apical tip of the macromere 3D establishes a close contact with a number of micromeres. Via its tip, the macromere 3D is supposed to receive an inductive signal from the micromeres, resulting in the determination of the mesodermal stem cell 4d at the next division. In view of the possibility that transcellular ionic currents might somehow be involved, either in the processes that bring about this particular configuration of blastomeres or in the induction process itself, we mapped the electric field around the embryo during the 24-cell stage, using a vibrating probe. We detected a reversal of the current direction as compared to the uncleaved egg, whilst the polarity of the field along the animal-vegetal axis was maintained. We also mapped the localization of Ca²⁺-stimulated AT-Pase, an enzyme that drives the Ca²⁺-efflux from the cell. We found that this enzyme is localized exclusively along the cytoplasmic face of the apical plasma membrane of macromere 3D, and that its presence is restricted to the period from 110 to 135 min after the fifth cleavage, when there is close contact between macormere 3D and the micromeres. Since the localization of the Ca²⁺-stimulated ATPase coincides both in time and space with the induction of the mesoderm-mother cell, we suggest that localized calcium fluxes may play a role in this induction process.     

The Toxicology of PCB's—An Overview for Clinicians

Polychlorinated biphenyls (PCB''s) have low acute toxicity but are of public health concern because of their persistence in the environment, the bioaccumulation in human and animal tissues, and their potential for chronic or delayed toxicity.Although many questions remain unanswered, it is clear that occupational exposure, at a minimum, can produce dermatologic effects and liver dysfunction. The long half-life of PCB''s and their presence in various human tissues leaves open the possibility of substantial chronic and delayed effects analogous to those seen in animals. PCB''s are potent inhibitors of reproductive function in both rodents and nonhuman primates and produce liver tumors in animal cancer bioassays. As potent inducers of hepatic enzyme systems, PCB''s may have additional unpredictable long-term health effects.These effects have only recently begun to be studied in a rigorous manner, and although the epidemiological evidence is neither complete nor entirely consistent, there can be no question of the necessity to keep human exposures to the lowest feasible levels.     

Muscle spindles in muscle control

In a previous paper (Inbar, 1972/III) a new adaptive model was proposed for muscular control. According to that scheme muscle spindles (MS) supply continuous information about the system dynamics. In the present study integral pulse frequency modulation (IPFM) is used to correlate MS afferent signals, recorded from frog sartorius muscle, to the same muscle dynamics, in order to establish the feasibility of the proposed MS role in the adaptive muscle model.