Production of syngenetic minerals with struvite by myxococcus coralloides D

The formation under laboratory conditions of newberyite, schertelite, and taylorite in conjunction with struvite by the bacterium Myxococcus coralloides D is reported for the first time. The presence of these syngenetic minerals with struvite was only detected in static liquid cultures.     

Active transport of CO2 by three species of marine microalgae

The occurrence of an active CO₂ transport system and of carbonic anhydrase (CA) has been investigated by mass spectrometry in the marine, unicellular rhodophyte Porphyridium cruentum (S.F. Gray) Naegeli and two marine chlorophytes Nannochloris atomus Butcher and Nannochloris maculata Butcher. Illumination of darkened cells incubated with 100 μM H¹³CO₃^? caused a rapid initial drop, followed by a slower decline in the extracellular CO₂ concentration. Addition of bovine CA to the medium raised the CO₂ concentration by restoring the HCO₃^?–CO₂ equilibrium, indicating that cells were taking up CO₂ and were maintaining the CO₂ concentration in the medium below its equilibrium value during photosynthesis. Darkening the cell suspensions caused a rapid increase in the extracellular CO₂ concentration in all three species, indicating that the cells had accumulated an internal pool of unfixed inorganic carbon. CA activity was detected by monitoring the rate of exchange of ¹⁸O from ¹³C¹⁸O₂ into water. Exchange of ¹⁸O was rapid in darkened cell suspensions, but was not inhibited by 500 μM acetazolamide, a membrane‐impermeable inhibitor of CA, indicating that external CA activity was not present in any of these species. In all three species, the rate of exchange was completely inhibited by 500 μM ethoxyzolamide, a membrane‐permeable CA‐inhibitor, showing that an intracellular CA was present. These results demonstrate that the three species are capable of CO₂ uptake by active transport for use as a carbon source for photosynthesis.     

Biochemical and hematologic reference intervals for the endangered island fox (Urocyon littoralis)

Hematologic and serum biochemical data collected must be interpreted by comparison with normal reference intervals generated from healthy animals, within a similar population, because many blood parameters are influenced by diet, environment, and stress. Species-specific reference intervals for the endangered island fox (Urocyon littoralis) are not available. We reviewed hematology and serum biochemistry panels from 280 island foxes sampled from 1999-2008 and established normal reference intervals from clinically healthy foxes using a nonparametric approach. Blood parameters were analyzed for differences in age, sex, island of origin, and captivity status. Alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities, as well as calcium and phosphorus concentrations, were significantly higher in juveniles than in adults, but total protein and globulin concentration was lower for juveniles than for adults. Lymphocyte and eosinophil counts, and blood urea nitrogen (BUN) concentration, in foxes from the northern Channel islands of California, USA (Santa Cruz, Santa Rosa, and San Miguel) were higher when compared with foxes from Santa Catalina Island to the south. Higher lymphocyte and eosinophil numbers in the northern island foxes may be associated with increased levels of parasitism on the northern islands. Differences in BUN concentration in both free-ranging and captive foxes may reflect dietary differences among islands. Although aggressive conservation programs have been enacted, island foxes are still susceptible to infectious and neoplastic diseases and, potentially, to toxins. Island fox species-specific reference intervals will enable managers and veterinarians to better care for sick and injured foxes and will contribute to future population health monitoring.     

New tacrine-dihydropyridine hybrids that inhibit acetylcholinesterase, calcium entry, and exhibit neuroprotection properties

In this communication, we describe the synthesis and biological evaluation of tacripyrimedones 1-5, a series of new tacrine-1,4-dihydropyridine hybrids bearing the general structure of 11-amino-12-aryl-3,3-dimethyl-3,4,5,7,8,9,10,12-octahydrodibenzo[b,g][1,8]naphthyridine-1(2H)-one. These multifunctional compounds are moderately potent and selective AChEIs, with no activity toward BuChE. Kinetic analysis and molecular modeling studies point out that the new compounds preferentially bind the peripheral anionic site of AChE. In addition, compounds 1-5 show an excellent neuroprotective profile, and a moderate blocking effect of L-type voltage-dependent calcium channels due to the mitigation of [Ca(2+)] elevation elicited by K(+) depolarization. Therefore, they represent a new family of molecules with potential therapeutic application for the treatment of Alzheimer's disease.     

Dark side of cyanobacteria: searching for strategies to control blooms

Cyanobacteria are ecologically one of the most prolific groups of photosynthetic prokaryotes in marine and freshwater habitats. They are primary producer microorganisms and are involved in the production of important secondary metabolites, including toxic compounds such as cyanotoxins. Environmental conditions promote massive growth of these microbes, causing blooms that can have critical ecological and public health implications. In this highlight, we discuss some of the approaches being addressed to prevent these blooms, such as control of nutrient loading, treatments to minimize growth or monitoring interactions with other species.     

Changes in mitochondrial and microsomal rat liver coenzyme Q9 and Q10 content induced by dietary fat and endogenous lipid peroxidation

The influence of different kinds of dietary fat (8%) and of endogenous lipid peroxidation with regard to coenzyme Q9 (CoQ9) and coenzyme Q10 (CoQ10) concentrations in mitochondria and microsomes from rat liver has been investigated by means of an HPLC technique. Although the different diet fats used did not produce any effect on microsomes, it was possible to show that each experimental diet differently influenced the mitochondrial levels of CoQ9 and CoQ10. The highest mitochondrial CoQ content was found in case of a diet supplemented with corn oil. An endogenous oxidative stress induced by adriamycin was able to produce a sharp decrease in mitochondrial CoQ9 levels in the rats to which corn oil was administered. The results suggest that dietary fat ought to be considered when studies concerning CoQ mitochondrial levels are carried out.     

Modulating the Expression Strength of the Baculovirus/Insect Cell Expression System: A Toolbox Applied to the Human Tumor Suppressor SMARCB1/SNF5

The human tumor suppressor SMARCB1/INI1/SNF5/BAF47 (SNF5) is a core subunit of the multi-subunit ATP-dependent chromatin remodeling complex SWI/SNF, also known as Brahma/Brahma-related gene 1 (BRM/BRG1)-associated factor (BAF). Experimental studies of SWI/SNF are currently considerably limited by the low cellular abundance of this complex; thus, recombinant protein production represents a key to obtain the SWI/SNF proteins for molecular and structural studies. While the expression of mammalian proteins in bacteria is often difficult, the baculovirus/insect cell expression system can overcome limitations of prokaryotic expression systems and facilitate the co-expression of multiple proteins. Here, we demonstrate that human full-length SNF5 tagged with a C-terminal 3?×?FLAG can be expressed and purified from insect cell extracts in monomeric and dimeric forms. To this end, we constructed a set of donor and acceptor vectors for the expression of individual proteins and protein complexes in the baculovirus/insect cell expression system under the control of a polyhedrin (polh), p10, or a minimal Drosophila melanogaster Hsp70 promoter. We show that the SNF5 expression level could be modulated by the selection of the promoter used to control expression. The vector set also comprises vectors that encode a 3?×?FLAG tag, Twin-Strep tag, or CBP-3?×?FLAG-TEV-ProteinA triple tag to facilitate affinity selection and detection. By gel filtration and split-ubiquitin assays, we show that human full-length SNF5 has the ability to self-interact. Overall, the toolbox developed herein offers the possibility to flexibly select the promoter strength as well as the affinity tag and is suggested to advance the recombinant expression of chromatin remodeling factors and other challenging proteins.