Residues of spinosad in the tissues of sheep after aerosol treatment of blowfly myiasis

Objective To measure the residues of spinosad and chlorhexidine in the tissues of sheep after treatment of blowfly strike. Procedure Fourteen sheep with natural myiasis and 12 with artificial infestations of Lucilia cuprina larvae had the wool removed over their infestations and were treated with an aerosol wound dressing containing spinosad and chlorhexidine. Sheep were killed up to 14 days after treatment and residues of the chemicals measured in tissues. Results Chlorhexidine was not detected in any tissue. Residues of spinosad were highest in fat, lowest in muscle and intermediate in liver and kidney. The highest residue detected was 0.2 mg/kg spinosad in perirenal fat 7 days after generous treatment of a sheep with a large fly strike. Residues of spinosad in fat peaked 3 to 7 days after treatment and 1 to 3 days after treatment in liver and kidney. Conclusion These studies present a realistic worst-case in struck sheep and at the highest dose studied, equivalent to 5.8 mg spinosad per kg body weight, the maximum residue detected of 0.2 mg/kg in peri-renal fat was 20% of the Australian maximum residue limit. Muscle, liver and kidney residues of spinosad were also below the Australian maximum residue limits at all times.

Production of fibrolytic enzymes by Aspergillus japonicus C03 using agro-industrial residues with potential application as additives in animal feed

Solid-state fermentation obtained from different and low-cost carbon sources was evaluated to endocellulases and endoxylanases production by Aspergillus japonicus C03. Regarding the enzymatic production the highest levels were observed at 30 degrees C, using soy bran added to crushed corncob or wheat bran added to sugarcane bagasse, humidified with salt solutions, and incubated for 3 days (xylanase) or 6 days (cellulase) with 70% relative humidity. Peptone improved the xylanase and cellulase activities in 12 and 29%, respectively. The optimum temperature corresponded to 60 degrees C and 50-55 degrees C for xylanase and cellulase, respectively, both having 4.0 as optimum pH. Xylanase was fully stable up to 40 degrees C, which is close to the rumen temperature. The enzymes were stable in pH 4.0-7.0. Cu(++) and Mn(++) increased xylanase and cellulase activities by 10 and 64%, respectively. A. japonicus C03 xylanase was greatly stable in goat rumen fluid for 4 h during in vivo and in vitro experiments.

EEG-based Brain-Computer Interfaces: An Overview of Basic Concepts and Clinical Applications in Neurorehabilitation

Some patients are no longer able to communicate effectively or even interact with the outside world in ways that most of us take for granted. In the most severe cases, tetraplegic or post-stroke patients are literally `locked in` their bodies, unable to exert any motor control after, for example, a spinal cord injury or a brainstem stroke, requiring alternative methods of communication and control. But we suggest that, in the near future, their brains may offer them a way out. Non-invasive electroencephalogram (EEG)-based brain-computer interfaces (BCD can be characterized by the technique used to measure brain activity and by the way that different brain signals are translated into commands that control an effector (e.g., controlling a computer cursor for word processing and accessing the internet). This review focuses on the basic concepts of EEG-based BC!, the main advances in communication, motor control restoration and the down-regulation of cortical activity, and the mirror neuron system (MNS) in the context of BCI. The latter appears to be relevant for clinical applications in the coming years, particularly for severely limited patients. Hypothetically, MNS could provide a robust way to map neural activity to behavior, representing the high-level information about goals and intentions of these patients. Non-invasive EEG-based BCIs allow brain-derived communication in patients with amyotrophic lateral sclerosis and motor control restoration in patients after spinal cord injury and stroke. Epilepsy and attention deficit and hyperactive disorder patients were able to down-regulate their cortical activity. Given the rapid progression of EEG-based BCI research over the last few years and the swift ascent of computer processing speeds and signal analysis techniques, we suggest that emerging ideas (e.g., MNS in the context of BC!) related to clinical neuro-rehabilitation of severely limited patients will generate viable clinical applications in the near future.

Macrocycle formation through carbon acid-formaldehyde condensation reactions of bis(propane-1,2-diamine)- and bis (2-methylpropane-1,2-diamine)-copper(II) ions

The reaction of the bis(1,2-diamine) copper(II) complexes of racemic propane-1,2-diamine (pn) and 2-methylpropane-1,2-diamine (dmen) with formaldehyde and nitroethane in methanol under basic conditions yields minor macrocyclic condensation products in addition to the major acyclic products. Where C-pendant methyl groups on the pair of coordinated diamines are in cis dispositions, the first -NH-CH2-C(CH3)(NO2)-CH2-NH- ring formation occurs at amine pairs distant from these C-methyl substituents, and further reaction to yield a macrocycle is not observed. However, where the C-methyl substituents are in trans dispositions, the chemistry proceeds to yield the macrocycle. Commencing with pn, trans-(6,13-diammonio-2,6,9,13-tetramethyl-1,4,7,10-tetraazacyclotetradecane)copper(II) perchlorate formed and crystallized in the space group P2(1)/n, with a 9.782(2), b 9.2794(6), c 17.017(4) Angstrom, beta 103.24(1)degrees. The copper ion is found in a square-planar environment, with the two methyl groups of the pn residues and the pairs of introduced pendant groups all in trans arrangements.

Autopathogenic T helper cell type 1 (Th1) and protective Th2 clones differ in their recognition of the autoantigenic peptide of myelin proteolipid protein

We previously generated a panel of T helper cell 1 (Th1) clones specific for an encephalitogenic peptide of myelin proteolipid protein (PLP) peptide 139-151 (HSLGKWLGHPDKF) that induces experimental autoimmune encephalomyelitis (EAE) upon adoptive transfer. In spite of the differences in their T cell receptor (TCR) gene usage, all these Th1 clones required W144 as the primary and most critical TCR contact residue for the activation. In this study, we determined the TCR contact residues of a panel of Th2/Th0 clones specific for the PLP peptide 139-151 generated either by immunization with the PLP 139-151 peptide with anti-B7-1 antibody or by immunization with an altered peptide Q144. Using alanine-substituted peptide analogues of the native PLP peptide, we show that the Th2 clones have shifted their primary contact residue to the NH2-terminal end of the peptide. These Th2 cells do not show any dependence on the W144, but show a critical requirement for L141/G142 as their major TCR contact residue. Thus, in contrast with the Th1 clones that did not proliferate to A144-substituted peptide, the Th2 clones tolerated a substitution at position 144 and proliferated to A144 peptide. This alternative A144 reactive repertoire appears to have a critical role in the regulation of autoimmune response to PLP 139-151 because preimmunization with A144 to expand the L141/G142-reactive repertoire protects mice from developing EAE induced with the native PLP 139-151 peptide. These data suggest that a balance between two different T cell repertoires specific for same autoantigenic epitope can determine disease phenotype, i.e., resistance or susceptibility to an autoimmune disease.

Evaluation of interventions to reduce catheter-associated bloodstream infection: Continuous tailored education versus one basic lecture

Background: This study evaluated the impact of 2 models of educational intervention on rates of central venous catheter-associated bloodstream infections (CVC-BSIs). Methods: This was a prospective observational study conducted between January 2005 and June 2007 in 2 medical intensive care units (designated ICU A and ICU B) in a large teaching hospital. The study was divided into in 3 periods: baseline (only rates were evaluated), preintervention (questionnaire to evaluate knowledge of health care workers [HCWs] and observation of CVC care in both ICUs), and intervention (in ICU A, tailored, continuous intervention; in ICU B, a single lecture). The preintervention and intervention periods for each ICU were compared. Results: During the preintervention period, 940 CVC-days were evaluated in ICUA and 843 CVC-days were evaluated in ICU B. During the intervention period, 2175 CVC-days were evaluated in ICUA and 1694 CVC-days were evaluated in ICU B. Questions regarding CVC insertion, disinfection during catheter manipulation, and use of an alcohol-based product during dressing application were answered correctly by 70%-100% HCWs. Nevertheless, HCWs` adherence to these practices in the preintervention period was low for CVC handling and dressing, hand hygiene (6%-35%), and catheter hub disinfection (45%-68%). During the intervention period, HCWs` adherence to hand hygiene was 48%-98%, and adherence to hub disinfection was 82%-97%. CVC-BSI rates declined in both units. In ICUA, this decrease was progressive and sustained, from 12CVC-BSIs/1000 CVC-days at baseline to 0 after 9 months. In ICU B, the rate initially dropped from 16.2 to 0 CVC-BSIs/1000 CVC-days, but then increased to 13.7 CVC-BSIs/1000 CVC-days. Conclusion: Personal customized, continuous intervention seems to develop a ""culture of prevention"" and is more effective than single intervention, leading to a sustained reduction of infection rates.

Neuromuscular activity of BaTX, a presynaptic basic PLA(2) isolated from Bothrops alternatus snake venom

We have previously isolated a Lys49 phospholipase A(2) homolog (BaTX) from Bothrops alternatus snake venom using a combination of molecular exclusion chromatography and reverse phase HPLC and shown its ability to cause neuromuscular blockade. In this work, we describe a one-step procedure for the purification of this toxin and provide further details of its neuromuscular activity. The toxin was purified by reverse phase HPLC and its purity and molecular mass were confirmed by SIDS-PAGE, MALDI-TOF mass spectrometry, amino acid analysis and N-terminal sequencing. BaTX (0.007-1.4 mu M) produced time-dependent, irreversible neuromuscular blockade in isolated mouse phrenic nerve-diaphragm and chick biventer cervicis preparations (time to 50% blockade with 0.35 mu M toxin: 58 +/- 4 and 24 +/- 1 min, respectively; n = 3-8; mean +/- S.E.) without significantly affecting the response to direct muscle stimulation. In chick preparations, contractures to exogenous acetylcholine (55 and 110 mu M) or KCl (13.4 mM) were unaltered after complete blockade by all toxin concentrations. These results, which strongly suggested a presynaptic mechanism of action for this toxin, were reinforced by (1) the inability of BaTX to interfere with the carbachol-induced depolarization of the resting membrane, (2) a significant decrease in the frequency and amplitude of miniature end-plate potentials, and (3) a significant reduction (59 +/- 4%, n=12) in the quantal content of the end-plate potentials after a 60 min incubation with the toxin (1.4 mu M). In addition, a decrease in the organ bath temperature from 37 degrees C to 24 degrees C and/or the replacement of calcium with strontium prevented the neuromuscular blockade, indicating a temperature-dependent effect possibly mediated by enzymatic activity. (C) 2009 Elsevier Inc. All rights reserved.

Diabetes and Vascular Disease: Basic Concepts of Nitric Oxide Physiology, Endothelial Dysfunction, Oxidative Stress and Therapeutic Possibilities

The vascular manifestations associated with diabetes mellitus (DM) result from the dysfunction of several vascular physiology components mainly involving the endothelium, vascular smooth muscle and platelets. It is also known that hyperglycemia-induced oxidative stress plays a role in the development of this dysfunction. This review considers the basic physiology of the endothelium, especially related to the synthesis and function of nitric oxide. We also discuss the pathophysiology of vascular disease associated with DM. This includes the role of hyperglycemia in the induction of oxidative stress and the role of advanced glycation end-products. We also consider therapeutic strategies.

Probing the effect of vehicles on topical delivery: Understanding the basic relationship between solvent and solute penetration using silicone membranes

Purpose. In the present study we examined the relationship between solvent uptake into a model membrane (silicone) with the physical properties of the solvents (e.g., solubility parameter, melting point, molecular weight) and its potential predictability. We then assessed the subsequent topical penetration and retention kinetics of hydrocortisone from various solvents to define whether modifications to either solute diffusivity or partitioning were dominant in increasing permeability through solvent-modified membranes. Methods. Membrane sorption of solvents was determined from weight differences following immersion in individual solvents, corrected for differences in density. Permeability and retention kinetics of H-3-hydrocortisone, applied as saturated solutions in the various solvents, were determined over 48 h in horizontal Franz-type glass diffusion cells. Results. Solvent sorption into the membrane could be related to differences in solubility parameters, MW and hydrogen bonding (r(2) = 0.76). The actual and predicted volume of solvent sorbed into the membrane was also found to be linearly related to Log hydrocortisone flux, with changes in both diffusivity and partitioning of hydrocortisone observed for the different solvent vehicles. Conclusions. A simple structure-based predictive model can be applied to the sorption of solvents into silicone membranes. Changes in solute diffusivity and partitioning appeared to contribute to the increased hydrocortisone flux observed with the various solvent vehicles. The application of this predictive model to the more complex skin membrane remains to be determined.

Tyrosine residue 271 of the norepinephrine transporter is an important determinant of its pharmacology

The aim was to examine the functional importance in the norepinephrine transporter (NET) of (i) the phenylalanine residue at position 531 in transmembrane domain (TMD) 11 by mutating it to tyrosine in the rat (rF531Y) and human (hF531Y) NETs and (ii) the highly conserved tyrosine residues at positions 249 in TMD 4 of human NET (hNET) (mutated to alanine: hY249A) and 271 in TMD 5, by mutating to alanine (hY271A), phenylalanine (hY271F) and histidine (hY271H). The effects of the mutations on NET function were for uptake of the substrates, examined by expressing the mutant and wildtype NETs in COS-7 cells and measuring the K-m and V-max for uptake of the substrates, [H-3]norepinephrine, [H-3]MPP+ and [H-3]dopamine, the K-D and B-max for [H-3]nisoxetine binding and the K-i of the inhibitors, nisoxetine, desipramine and cocaine, for inhibition of [H-3]norepinephrine uptake. The K-m values of the substrates were lower for the mutants at amino acid 271 than hNET and unaffected for the other mutants, and each mutant had a significantly lower than NET for substrate uptake. The mutations at position 271 caused an increase in the K-i or K-D values of nisoxetine, desipramine and cocaine, but there were no effects for the other mutations. Hence, the 271 tyrosine residue in TMD 5 is an important determinant of NET function, with the mutants showing an increase in the apparent affinities of substrates and a decrease in the apparent affinities of inhibitors, but the 249 tyrosine and 531 phenylalanine residues do not have a major role in determining NET function. (C) 2001 Elsevier Science B.V. All rights reserved.