The regulatory protein GAL80 is a determinant of the chromatin structure of the yeast GAL1-10 control region

Chromatin in the regions between the upstream activator sequence and the 5' ends of the yeast GAL1 and GAL10 genes has been analyzed by DNase I chromosomal footprinting and micrococcal nuclease digestion using the indirect end-labeling approach. Comparison of wild type chromatin digests to naked DNA digests shows that there are specific regions of these upstream sequences which are strongly protected in chromatin. Comparison to chromatin digests from cells disrupted for the positive regulatory gene, GAL4, or the negative regulatory gene, GAL80, and thus lacking GAL4 or GAL80 function, shows that these regions of protection in wild type chromatin are GAL80-dependent but not GAL4-dependent. The protected regions include DNA lying on (GAL10) or near (GAL1) the respective TATA boxes. These protections are present in both noninduced and induced cells. Both DNA strands are equally protected. Upstream of GAL1 there is a second protected region. This protection shows considerable expression and strand dependence. These observations provide the first evidence that the GAL80 function influences chromatin structure and suggest possible mechanisms by which GAL80 modulates the GAL1 and 10 promoters in induced cells. Micrococcal nuclease digests also suggest a role for GAL80 in a distinctive higher order organization of the intergenic region, perhaps involving multiprotein complexes.     

Effect of acute and chronic hypernatremia on myoinositol and sorbitol concentration in rat brain and kidney

In animal models of hypernatremia, increases in brain electrolyte content account for the entire increase in osmolality in acute but not chronic hypernatremia, suggesting that there is generation of additional intracellular solutes ("idiogenic osmoles") in chronic hypernatremic states. In the present study, the concentration of the polyols myoinositol and sorbitol and water content were determined in the brain and kidneys of rats made acutely (2 hours) and chronically (72 hours) hypernatremic by intraperitoneal injection of NaCl and water restriction. Both the brain and the kidney responded to chronic hypernatremia with increased levels of myoinositol. Sorbitol levels increased in the kidney in response to both acute and chronic hypernatremia. Water content dropped in acute hypernatremia, but remained unchanged during chronic hyperosmolar challenge. We conclude that the polyols, myoinositol and sorbitol, may play a significant role in cellular osmoregulation in brain and kidney during chronic hypernatremia in the rat.     

Amphotericin B alters the affinity and functional activity of the oligopeptide chemotactic factor receptor on human polymorphonuclear leukocytes

Leukocyte chemotaxis is initiated by the binding of chemotactic factors to specific, high-affinity receptors. Amphotericin B, a polyene antibiotic that binds to membrane cholesterol, inhibits human neutrophil (PMN) chemotaxis. We examined the effects of this drug on PMN functions mediated by the oligopeptide chemotactic factor receptor. The antibiotic irreversibly inhibited chemotaxis and depressed the binding of the radiolabeled chemoattractant, fMet-Leu-[3H]Phe, to its receptor without affecting the receptor's specificity. The drug lowered the binding affinity of the receptor by up to fivefold and slightly increased its number. Doses of amphotericin B that depressed receptor affinity and inhibited chemotaxis did not diminish lysosomal enzyme secretion or superoxide anion production. Nystatin, a less potent polyene antibiotic, also diminished chemotactic factor binding, but to a lesser degree than amphotericin B did. A chemically unrelated antifungal agent had no effect on either binding or chemotaxis. Thus, pharmacologic manipulation can alter the affinity of the chemotactic factor receptor on human PMN; this alteration is associated with a change in receptor function. The data suggest that receptor affinity regulates or at least reflects its functional state, and that the transduction mechanisms for various biologic responses mediated by the chemoattractant receptor are heterogeneous. By pharmacologic alterations of receptor affinity, one may be able to modulate specific biologic responses elicited by chemoattractant receptor-ligand interactions.     

Structure of the chromosomal copy of yeast ARS1

We have used deoxyribonuclease I (DNase I) and methidium-propyl-EDTA.Fe(II) digestion to characterize the chromosomal structure of the single-copy autonomously replicating sequence ARS1. The major feature of this chromatin is a region of strong hypersensitivity to both cleavage agents. The hypersensitive region contains most of the DNA sequences which have been suggested by in vitro mutagenesis studies [Celniker, S., Sweder, K., Srienc, F., Bailey, J., & Campbell, J. (1984) Mol. Cell. Biol. 4, 2455-2466] to be important in ARS function. It lies at the downstream end of the TRP1 gene. A chromosomal DNase I footprinting analysis was carried out on the hypersensitive region. These data give direct evidence for several localized DNA/protein contacts within the hypersensitive region. The most prominent of these chromatin-dependent contacts is located on the functionally most important 11 base pairs of ARS DNA. On the TRP1 side of the hypersensitive region, there are positioned nucleosomes. On the other side of the hypersensitive region, there is a complex (and possibly heterogeneous) structure.     

Pediatric SubQ-ICD implantation,a single center review of the inter-muscular technique

IntroductionPediatric patients with cardiomyopathies are at risk for sudden death and may need implantable cardioverter defibrillators (ICD’s), but given their small size and duration of use, children are at increased risk for complications associated with ICD use. The subcutaneous ICD presents a favorable option for children without pacing indications. Unfortunately, initial pediatric studies have demonstrated a high complication rate, likely due to the 3-incision technique employed.Material and methodsPatients with ICD but no pacing indication were retrospectively reviewed after implantation of subcutaneous ICD via the two-incision technique. In half of the patients, 10-J impedance test was also performed to compare with impedance obtained after defibrillation threshold testing with 65-J.ResultsTwelve patients were included. The median age was 14 years (range 10–16 years) with eight males included (72.7%). The median weight was 55 kg (range 29 kg–75.1 kg). Follow-up had a median of 11.5 months (range 2–27 months). The median body mass index was 18.4 kg/m squared (range 15.5–27.9 kg/m squared). One patient suffered a minor complication after tearing off the incisional adhesive strips early and required a non-invasive repair in clinic. Shock impedance had a median of 55 J (range 48–68 J). There was one appropriate shock/charge and no inappropriate shocks during follow-up.ConclusionThe two-incision, intermuscular technique appears to have a lower acute complication rate than prior reports, in our cohort of 12 pediatric patients.     

Acoustic sequences in non‐human animals: a tutorial review and prospectus

Animal acoustic communication often takes the form of complex sequences, made up of multiple distinct acoustic units. Apart from the well‐known example of birdsong, other animals such as insects, amphibians, and mammals (including bats, rodents, primates, and cetaceans) also generate complex acoustic sequences. Occasionally, such as with birdsong, the adaptive role of these sequences seems clear (e.g. mate attraction and territorial defence). More often however, researchers have only begun to characterise – let alone understand – the significance and meaning of acoustic sequences. Hypotheses abound, but there is little agreement as to how sequences should be defined and analysed. Our review aims to outline suitable methods for testing these hypotheses, and to describe the major limitations to our current and near‐future knowledge on questions of acoustic sequences. This review and prospectus is the result of a collaborative effort between 43 scientists from the fields of animal behaviour, ecology and evolution, signal processing, machine learning, quantitative linguistics, and information theory, who gathered for a 2013 workshop entitled, ‘Analysing vocal sequences in animals’. Our goal is to present not just a review of the state of the art, but to propose a methodological framework that summarises what we suggest are the best practices for research in this field, across taxa and across disciplines. We also provide a tutorial‐style introduction to some of the most promising algorithmic approaches for analysing sequences. We divide our review into three sections: identifying the distinct units of an acoustic sequence, describing the different ways that information can be contained within a sequence, and analysing the structure of that sequence. Each of these sections is further subdivided to address the key questions and approaches in that area. We propose a uniform, systematic, and comprehensive approach to studying sequences, with the goal of clarifying research terms used in different fields, and facilitating collaboration and comparative studies. Allowing greater interdisciplinary collaboration will facilitate the investigation of many important questions in the evolution of communication and sociality.     

Salt‐enhanced cultivation as a morphology engineering tool for filamentous actinomycetes: Increased production of labyrinthopeptin A1 in Actinomadura namibiensis

Salt‐enhanced cultivation as a morphology engineering tool for the filamentous actinomycete Actinomadura namibiensis was evaluated in 500‐mL shaking flasks (working volume 100 mL) with the aim of increasing the concentration of the pharmaceutically interesting peptide labyrinthopeptin A1. Among the inorganic salts added to a complex production medium, the addition of (NH₄)₂SO₄ led to the highest amount of labyrinthopeptin A1 production. By using 50 mM (NH₄)₂SO₄, the labyrinthopeptin A1 concentration increased up to sevenfold compared to the non‐supplemented control, resulting in 325 mg L^?1 labyrinthopeptin A1 after 10 days of cultivation. The performance of other ammonium‐ and sulfate‐containing salts (e.g., NH₄Cl, K₂SO₄) was much lower than the performance of (NH₄)₂SO₄. A positive correlation between the uptake of glycerol as one of the main carbon sources and nongrowth‐associated labyrinthopeptin productivity was found. The change in the cell morphology of A. namibiensis in conjunction with increased osmolality by the addition of 50 mM (NH₄)₂SO₄, was quantified by image analysis. A. namibiensis always developed a heterogeneous morphology with pellets and loose mycelia present simultaneously. In contrast to the non‐supplemented control, the morphology of (NH₄)₂SO₄‐supplemented cultures was characterized by smaller and circular pellets that were more stable against disintegration in the stationary production phase.     

Optimizing return‐on‐effort for coral nursery and outplanting practices to aid restoration of the Great Barrier Reef

Coral nursery and outplanting practices have grown in popularity worldwide for targeted restoration of degraded “high value” reef sites, and recovery of threatened taxa. Success of these practices is commonly gauged from coral propagule growth and survival, which fundamentally determines the return‐on‐effort (RRE) critical to the cost‐effectiveness and viability of restoration programs. In many cases, RRE has been optimized from past successes and failures, which therefore presents a major challenge for locations such as the Great Barrier Reef (GBR) where no local history of restoration exists to guide best practice. In establishing the first multi‐taxa coral nursery on the GBR (Opal Reef, February 2018), we constructed a novel scoring criterion from concurrent measurements of growth and survivorship to guide our relative RRE, including nursery propagule numbers (stock density). We initially retrieved RRE scores from a database of global restoration efforts to date (n = 246; 52 studies) to evaluate whether and how success commonly varied among coral taxa. We then retrieved RRE scores for Opal Reef using initial growth and survivorship data for six key coral taxa, to demonstrate that RRE scores were high for all taxa predominantly via high survivorship over winter. Repeated RRE scoring in summer is therefore needed to capture the full dynamic range of success where seasonal factors regulating growth versus survivorship differ. We discuss how RRE scoring can be easily adopted across restoration practices globally to standardize and benchmark success, but also as a tool to aid decision‐making in optimizing future propagation (and outplanting) efforts.