Activation of central melanocortin pathways by fenfluramine

D-fenfluramine (d-FEN) was once widely prescribed and was among the most effective weight loss drugs, but was withdrawn from clinical use because of reports of cardiac complications in a subset of patients. Discerning the neurobiology underlying the anorexic action of d-FEN may facilitate the development of new drugs to prevent and treat obesity. Through a combination of functional neuroanatomy, feeding, and electrophysiology studies in rodents, we show that d-FEN-induced anorexia requires activation of central nervous system melanocortin pathways. These results provide a mechanistic explanation of d-FEN's anorexic actions and indicate that drugs targeting these downstream melanocortin pathways may prove to be effective and more selective anti-obesity treatments.     

Direct prediction of site-specific lime requirement of arable fields using the base neutralizing capacity and a multi-sensor platform for on-the-go soil mapping

Precision Agriculture - Liming agricultural fields is necessary for counteracting soil acidity and is one of the oldest operations in soil fertility management. However, the best management...     

Comparative evaluation of virulence and pathology of Streptococcus suis serotypes 2 and 9 in experimentally infected growers

Streptococcus (S.) suis is an invasive porcine pathogen causing meningitis, septicemia, arthritis and other diseases. Studies on pathogenesis as well as vaccine trials have focused on serotype 2 strains, which are worldwide the most prevalent among invasive isolates. However, in Europe serotype 9 strains also contribute substantially to S. suis-associated invasive diseases of piglets. The objective of this study was to determine the virulence of an MRP* SLY+ serotype 9 S. suis strain in comparison to an MRP+ EF+ SLY+ serotype 2 strain. Experimental intranasal and intravenous infections of 7-8 weeks old SPF piglets were investigated with regard to clinic and pathology. In contrast to the virulent serotype 2 strain, the serotype 9 strain did not cause disease with clinical manifestations after intranasal administration. However, histological screenings of these animals revealed pathological lesions, such as mild focal suppurative meningitis. Clinical manifestations related to meningitis, arthritis and serositis could be induced by intravenous application of this serotype 9 strain. Bacteriological culture and immunohistochemistry of the brain confirmed association with the S. suis challenge strains in all cases with clinical manifestations. Interestingly, expression of MRP within meningitis lesions was demonstrated for both pathotypes via immunohistochemistry. In conclusion, this study demonstrates that MRP* SLY+ serotype 9 strains are less virulent for growers than MRP+ EF+ SLY+ serotype 2 strains. Thus, intravenous application of this serotype 9 strain is required to evaluate heterologous protection in the course of vaccine development based on serotype 2 strains in the future.     

Multiplex qPCR assay for simultaneous quantification of CYP51-S524T and SdhC-H152R substitutions in European populations of Zymoseptoria tritici

Demethylation inhibitor (DMI) and succinate dehydrogenase inhibitor (SDHI) fungicides are currently relied upon for the control of septoria tritici blotch (STB) in European wheat fields. However, multiple mutations have occurred over time in the genes encoding the targeted proteins that have led to a practical loss of fungicide efficacies. Among the different amino acid substitutions in Zymoseptoria tritici associated with resistance to these fungicides, S524T in CYP51 (DMI target) and H152R in SdhC (SDHI target) are regarded as conferring the highest resistance factors to DMI and SDHI, respectively. To facilitate further studies on the monitoring and selection of these substitutions in Z. tritici populations, a multiplex allele-specific quantitative PCR (qPCR) assay allowing for estimation of both allele frequencies in bulk DNA matrices was developed. The assay was then used on complex DNA samples originating from a spore trap network set up in Belgium, Denmark, Sweden, and Ireland in 2017 and 2018, as well as on leaf samples with symptoms. The S524T allele was present in all field samples and its proportion was significantly higher in Ireland than in Belgium, whereas the proportion of H152R was only sporadically present in both countries. The frequency of S524T varied greatly in the airborne inoculum of all four countries; however, the H152R allele was never detected in the airborne inoculum. The method developed in this study can be readily adopted by other laboratories and used for multiple applications including resistance monitoring in field populations of Z. tritici.     

An outbreak of Shiga toxin‐producing Escherichia coli O157:H7 linked to a mud‐based obstacle course,England, August 2018

In August 2018, Public Health England (PHE) was made aware of five probable cases of Shiga toxin‐producing Escherichia coli (STEC) O157:H7 among individuals reporting participation in a mud‐based obstacle race. An additional four cases, identified via routine whole‐genome sequencing, were subsequently linked to the same event. Two of the nine cases were due to secondary household transmission. Despite an agreement between the event organizers and the local authority, to ensure that all livestock were removed from the site 28 days before the event, sheep were observed grazing on some of the routes taken by the runners 2 days prior to the race taking place. A retrospective review of incidents reported to PHE between 2015 and 2018 identified 41 cases of gastroenteritis associated with muddy assault course events. Of these, 25 cases were due to infection with STEC O157:H7, of which all but one were associated with outbreaks. Due to the environment in which such events take place, it is impossible to entirely remove the risk of exposure to potentially pathogenic zoonoses. However, race organizers should ensure that livestock are removed from the course 28 days before the event. They should also ensure that participants are made aware of the risk of contracting gastrointestinal disease from the environment, and to stress the importance of hand hygiene post‐event and the risk of secondary transmission, particularly to children who are at risk of developing haemolytic uraemic syndrome.     

FEASIBILITY OF ULTRASOUND‐GUIDED EPIDURAL ACCESS AT THE LUMBO‐SACRAL SPACE IN DOGS

Epidural injections are commonly performed blindly in veterinary medicine. The aims of this study were to describe the lumbosacral ultrasonographic anatomy and to assess the feasibility of an ultrasound‐guided epidural injection technique in dogs. A cross sectional anatomic atlas of the lumbosacral region and ex vivo ultrasound images were obtained in two cadavers to describe the ultrasound anatomy and to identify the landmarks. Sixteen normal weight canine cadavers were used to establish two variations of the technique for direct ultrasound‐guided injection, using spinal needles or epidural catheters. The technique was finally performed in two normal weight cadavers, in two overweight cadavers and in five live dogs with radiographic abnormalities resulting of the lumbosacral spine. Contrast medium was injected and CT was used to assess the success of the injection. The anatomic landmarks to carry out the procedure were the seventh lumbar vertebra, the iliac wings, and the first sacral vertebra. The target for directing the needle was the trapezoid‐shaped echogenic zone between the contiguous articular facets of the lumbosacral vertebral canal visualized in a parasagittal plane. The spinal needle or epidural catheter was inserted in a 45° craniodorsal–caudoventral direction through the subcutaneous tissue and the interarcuate ligament until reaching the epidural space. CT examination confirmed the presence of contrast medium in the epidural space in 25/25 dogs, although a variable contamination of the subarachnoid space was also noted. Findings indicated that this ultrasound‐guided epidural injection technique is feasible for normal weight and overweight dogs, with and without radiographic abnormalities of the spine.     

Volatile metabolites from actinomycetes

Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection and identified or characterized by gas chromatography-mass spectrometry. A total of 120 VOCs were characterized by retention index and mass spectra. Fifty-three compounds were characterized as terpenoid compounds, among which 18 could be identified. Among the VOCs were alkanes, alkenes, alcohols, esters, ketones, sulfur compounds, and isoprenoid compounds. Among the most frequently produced compounds were isoprene, acetone, 1-butanol, 2-methyl-1-propanol, 3-methyl-3-buten-1-ol, 3-methyl-1-butanol, 2-methyl-1-butanol, cyclopentanone, dimethyl disulfide, dimethyl trisulfide, 2-phenylethanol, and geosmin. The relationship between the excretion of geosmin and the production of spores was examined for one isolate. A good correlation between headspace geosmin and the number of spores was observed, suggesting that VOCs could be used to indicate the activity of these microorganisms in heterogeneous substrates.     

Pseudoperoxidase activity of myoglobin: kinetics and mechanism of the peroxidase cycle of myoglobin with H2O2 and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonate) as substrates

Using 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) as substrate, it has been shown that the increased peroxidase activity for decreasing pH of myoglobin activated by hydrogen peroxide is due to a protonization of ferrylmyoglobin, MbFe(IV)=O, facilitating electron transfer from the substrate and corresponding to pK(a) approximately 5.2 at 25.0 degrees C and ionic strength 0.16, rather than due to specific acid catalysis. On the basis of stopped flow absorption spectroscopy with detection of the radical cation ABTS(.+), the second-order rate constant and activation parameters for the reaction between MbFe(IV)=O and ABTS were found to have the values k = 698 +/- 32 M(-1) s(-1), DeltaH# = 66 +/- 4 kJ mol(-1), and DeltaS# = 30 +/- 15 J mol(-1) K(-1) at 25.0 degrees C and physiological pH (7.4) and ionic strength (= 0.16 M NaCl). At a lower pH (5.8) corresponding to the conditions in meat, values were found as follows: k = 3.5 +/- 0.3 x 10(4) M(-1) s(-1), DeltaH# = 31 +/- 6 kJ mol(-1), and DeltaS# = -53 +/- 19 J mol(-1) K(-1), indicative of a shift from outersphere electron transfer to an innersphere mechanism. For steady state assay conditions, this shift is paralleled by a shift from saturation kinetics at pH 7.4 to first-order kinetics for H2O2 as substrate at pH 5.8. In contrast, the activation reaction between myoglobin and hydrogen peroxide was found at 25.0 degrees C to be slow and independent of pH with values of 171 +/- 7 and 196 +/- 19 M(-1) s(-1) found at physiological and meat pH, respectively, as determined by sequential stopped flow spectroscopy, from which a lower limit of k = 6 x 10(5) M(-1) s(-1) for the reaction between perferrylmyoglobin, .MbFe(IV)=O, and ABTS could be estimated. As compared to the traditional peroxidase assay, a better characterization of pseudoperoxidase activity of heme pigments and their denatured or proteolyzed forms is thus becoming possible, and specific kinetic effects on activation, substrate oxidation, or shift in rate determining steps may be detected.     

Modification of Standard Enzymatic Protocol to a Cost‐Efficient Format for Mixed‐Linkage (1→3,1→4)‐β‐d‐Glucan Measurement

The current enzymatic assay approach (AACC International Approved Method 32‐23) for the measurement of mixed‐linkage β‐glucan in small grains was modified to a cost‐efficient and high‐throughput format without compromising the accuracy of the results. Ten barley (Hordeum vulgare L.) genotypes used in the study represented a wide range of β‐glucan content levels. A reduced reaction volume is used in the new protocol to adapt to a 96‐well plate format. The volume of key components lichenase and β‐glucosidase were reduced to 25% of the volume required in the original protocol and the cost per sample was reduced to 22% of that in the original protocol. Labor cost was also decreased to 25% of the original protocol as a result of format changes. The accuracy of the measurement from the modified protocol was comparable to the current standard enzymatic procedure. β‐Glucan measurement accuracy of the modified and original protocols were also compared using 21 oat (Avena sativa L.) samples. The results indicated that the new protocol consistently produced accurate measurements in both barley and oat.     

Effect of Physical State of Nonpolar Lipids on Rheology and Microstructure of Gluten‐Starch and Wheat Flour Doughs

To clarify the effects of solid fat and liquid oil on dough in more detail in a simpler system, gluten‐starch doughs with different gluten contents were investigated. The results from rheological measurements indicate that dough with a higher starch content has less resistance to strain and dough with a lower starch content has a rubber‐like structure. The effects of the physical state of nonpolar lipids such as fat and oil on gluten‐starch doughs and wheat flour doughs were investigated using rheological measurements and scanning electron microscopy. Fat‐containing dough had more gas cells and a very smooth gluten gel surface with few holes, which may provide higher tolerance to strain. Moreover, the fat seemed to uniformly distribute the gluten gel between the starch granules in the dough, which reduced the friction between starch granules and led to a lower storage modulus. A mechanism governing the effect of fats on loaf volume is proposed based on the phenomena observed in the fat‐containing dough.