The palatability of flavoured novel floating pellets made with brewer's spent grain to captive carp

Abstract

The palatability to common carp, Cyprinus carpio L. of three newly developed differently flavoured floating pellets made from a high proportion (40%) of brewer's spent grain (BSG) was tested using a multiple-offer feeding experiment. The addition of ‘bold’ flavours, such as vanilla or strawberry essence, may help mask the unpleasant taste of some piscicides; however, their inclusion must not compromise uptake by carp. There were no significant differences between the consumption rates of the three varieties, and all flavours were readily consumed. Therefore, it is suggested that highly flavoured pellets made with BSG have a strong potential to mask the flavour of an unpalatable toxin, and further research is now needed to test this hypothesis.     

Molecular dynamics simulations reveal that apo‐HisJ can sample a closed conformation

The Escherichia coli histidine binding protein HisJ is a type II periplasmic binding protein (PBP) that preferentially binds histidine and interacts with its cytoplasmic membrane ABC transporter, HisQMP₂, to initiate histidine transport. HisJ is a bilobal protein where the larger Domain 1 is connected to the smaller Domain 2 via two linking strands. Type II PBPs are thought to undergo “Venus flytrap” movements where the protein is able to reversibly transition from an open to a closed conformation. To explore the accessibility of the closed conformation to the apo state of the protein, we performed a set of all‐atom molecular dynamics simulations of HisJ starting from four different conformations: apo‐open, apo‐closed, apo‐semiopen, and holo‐closed. The simulations reveal that the closed conformation is less dynamic than the open one. HisJ experienced closing motions and explored semiopen conformations that reverted to closed forms resembling those found in the holo‐closed state. Essential dynamics analysis of the simulations identified domain closing/opening and twisting as main motions. The formation of specific inter‐hinge strand and interdomain polar interactions contributed to the adoption of the closed apo‐conformations although they are up to 2.5‐fold less prevalent compared with the holo‐closed simulations. The overall sampling of the closed form by apo‐HisJ provides a rationale for the binding of unliganded PBPs with their cytoplasmic membrane ABC transporters. Proteins 2014; 82:386–398. © 2013 Wiley Periodicals, Inc.     

Detrimental effects of albuterol on airway responsiveness requires airway inflammation and is independent of β-receptor affinity in murine models of asthma

Background

Inhaled short acting β2-agonists (SABA), e.g. albuterol, are used for quick reversal of bronchoconstriction in asthmatics. While SABA are not recommended for maintenance therapy, it is not uncommon to find patients who frequently use SABA over a long period of time and there is a suspicion that long term exposure to SABA could be detrimental to lung function. To test this hypothesis we studied the effect of long-term inhaled albuterol stereoisomers on immediate allergic response (IAR) and airway hyperresponsiveness (AHR) in mouse models of asthma.

Methods

Balb/C mice were sensitized and challenged with ovalbumin (OVA) and then we studied the IAR to inhaled allergen and the AHR to inhaled methacholine. The mice were pretreated with nebulizations of either racemic (RS)-albuterol or the single isomers (S)- and (R)-albuterol twice daily over 7 days prior to harvest.

Results

We found that all forms of albuterol produced a significant increase of IAR measured as respiratory elastance. Similarly, we found that AHR was elevated by albuterol. At the same time a mouse strain that is intrinsically hyperresponsive (A/J mouse) was not affected by the albuterol isomers nor was AHR induced by epithelial disruption with Poly-L-lysine affected by albuterol.

Conclusions

We conclude that long term inhalation treatment with either isomer of albuterol is capable of precipitating IAR and AHR in allergically inflamed airways but not in intrinsically hyperresponsive mice or immunologically naïve mice. Because (S)-albuterol, which lacks affinity for the β2-receptor, did not differ from (R)-albuterol, we speculate that isomer-independent properties of the albuterol molecule, other than β2-agonism, are responsible for the effect on AHR.     

长春净月潭地区土壤跳虫的生态分布

土壤动物直接参与土壤形成,它与土壤微生物的相互配合,对植物凋落物的分解起着十分重要的作用。土壤跳虫是土壤动物中最重要的类群之一。关于它的生态分布,目前国内报道不多。东北师范大学和日本九州大学合作,对长春净月潭地区的土壤跳虫进行了初步调查。     

Synthesis of a new 8-spin-labeled analog of adenosine 5'-phosphate and its interaction with AMP nucleosidase.

The synthesis of a new 8-spin-labeled analog of AMP, 8-[[[(2,2,5,5-tetramethyl-1-oxy-3-pyrrolidinyl)carbamoyl]methyl]thio]adenosine 5'-phosphate (8-slAMP), is described. The procedure is facile and results in high yields. 8-slAMP is a competitive inhibitor of AMP nucleosidase with a Ki of 19 microM as compared to a Km of 100 microM for AMP. The analog is not a substrate for the enzyme and does not displace MgATP2- from the allosteric sites under the usual assay conditions. The EPR spectrum of the bound spin probe reveals a highly immobilized nitroxide group. Binding studies with 8-slAMP at 8 degrees C indicate three independent binding sites (Kd = 1.4 microM) per molecule of enzyme (Mr = 320,000). These properties make 8-slAMP a good spin probe for AMP nucleosidase. The analog may also be useful for other proteins known or suspected of binding AMP analogs in a syn conformation.     

Apoptosis in polycystic kidney disease: involvement of caspases

Polycystic kidney disease (PKD) is characterized by the development of large renal cysts and progressive loss of renal function. Although the cause of the development of renal cysts is unknown, recent evidence suggests that excessive apoptosis occurs in PKD. With the use of terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, we have confirmed the presence of apoptotic bodies in cystic kidneys of congenital polycystic kidney (cpk) disease mice carrying a homozygous mutation at 3 wk of age. Apoptosis was localized primarily to the interstitium with little evidence of cell death in cyst epithelium or noncystic tubules. In addition, we observed that the expression of various caspases, bax and bcl-2, was upregulated in cystic kidneys. With the use of various substrates in enzyme activity assays, we have demonstrated a greater than sevenfold increase in caspase 4 activity and a sixfold increase in caspase 3 activity. These data suggest that there is a caspase-dependent apoptosis pathway associated with PKD and support the hypothesis that apoptotic cell death contributes to cyst formation in PKD.     

Inactivation of dopamine beta-hydroxylase by p-cresol: evidence for a second, minor site of covalent modification at tyrosine 357

p-Cresol is a mechanism-based inhibitor of bovine dopamine beta-hydroxylase (3,4-dihydroxyphenethylamine, ascorbate: oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1) (DBH) which covalently modifies a tyrosine at position 216 during inactivation (DeWolf, W.E., Jr., Carr, S.A., Varrichio, A., Goodhart, P.J., Mentzer, M.A., Roberts, G.D., Southan, C., Dolle, R.E. and Kruse, L.I. (1988) Biochemistry 27, 9093-9101). Here we report the recovery and characterization of additional minor peptides that are produced during the inactivation of DBH with p-[3H]cresol. Sequence and structural analysis of these peptides indicates tyrosine 357 as a second, minor site of modification.