[Calculation of therapeutic intensity for pigs treated using medicated feed]

INTRODUCTION

The correct oral treatment of pigs in groups is a demanding procedure. Prescriptions of medicated feed for groups larger than 20 pigs have to be made on official forms submitted to veterinary authorities. In this work, we evaluated 1'126 such forms for the years 2010-2011 to calculate the therapeutic intensity for piglets and fatteners at farm level in the canton of Lucerne. This analysis shows that essential data were often difficult to obtain and that the provided information did not always allow for plausible intensity calculations. In total, 654 and 424 kg of antimicrobials were prescribed during the 2 years under investigation. For the years 2010 and 2011, the calculated median intensities were 43.5 and 32.5 treated animals per 1'000 individuals per day (PIDvet) for piglets and 75.9 and 64.8 for fatteners. PIDvet for the whole populations of piglets and fatteners treated with medicated feed delivered from feed mills were 37.51 resp. 84.44 in the year 2011.

The human brain response to dental pain relief

Local anesthesia has made dental treatment more comfortable since 1884, but little is known about associated brain mechanisms. Functional magnetic resonance imaging is a modern neuroimaging tool widely used for investigating human brain activity related to sensory perceptions, including pain. Most brain regions that respond to experimental noxious stimuli have recently been found to react not only to nociception alone, but also to visual, auditory, and other stimuli. Thus, presumed functional attributions have come under scrutiny regarding selective pain processing in the brain. Evidently, innovative approaches are warranted to identify cerebral regions that are nociceptive specific. In this study, we aimed at circumventing known methodological confounders by applying a novel paradigm in 14 volunteers: rather than varying the intensity and thus the salience of painful stimuli, we applied repetitive noxious dental stimuli at constant intensity to the left mandibular canine. During the functional magnetic resonance imaging paradigm, we suppressed the nociceptive barrage by a mental nerve block. Brain activity before and after injection of 4% articaine was compared intraindividually on a group level. Dental pain extinction was observed to correspond to activity reduction in a discrete region of the left posterior insular cortex. These results confirm previous reports demonstrating that direct electrical stimulation of this brain region-but not of others-evokes bodily pain sensations. Hence, our investigation adds further evidence to the notion that the posterior insula plays a unique role in nociceptive processing.

Fear-learning deficits in subjects with fibromyalgia syndrome?

BACKGROUND

Fibromyalgia syndrome (FMS) is frequently associated with psychiatric conditions, particularly anxiety. Deficits in contingency learning during fear conditioning have been hypothesized to increase anxiety and, consequently, pain sensation in susceptible individuals. The goal of this study was to examine the relationship between contingency learning and pain experience in subjects with FMS and rheumatoid arthritis (RA).

METHODS

Fourteen female FMS subjects, 14 age-matched female RA subjects and 14 age-matched female healthy controls (HCs) were included in a fear-conditioning experiment. The conditioned stimulus (CS) consisted of visual signs, the unconditioned stimulus (US) of thermal stimuli. CS- predicted low-temperature exposure (US), while CS+ was followed by low or high temperature.

RESULTS

In the FMS group, only 50% of the subjects were aware of the US-CS contingency, whereas 86% of the RA subjects and all of the HCs were aware of the contingency. CS+ induced more anxiety than CS- in RA subjects and HCs. As expected, low-temperature exposure was experienced as less painful after CS- than after CS+ in these subjects. FMS subjects did not show such adaptive conditioning. The effects of the type of CS on heart rate changes were significant in the HCs and the aware FMS subjects, but not in the unaware FMS subjects.

CONCLUSIONS

Contingency learning deficits represent a potentially promising and specific, but largely unstudied, psychopathological factor in FMS. Deficits in contingency learning may increase anxiety and, consequently, pain sensation. These findings have the potential to contribute to the development of novel therapeutic approaches for FMS.

Tracing Toothache Intensity in the Brain

Identification of brain regions that differentially respond to pain intensity may improve our understanding of trigeminally mediated nociception. This report analyzed cortical responses to painless and painful electrical stimulation of a right human maxillary canine tooth. Functional magnetic resonance images were obtained during the application of five graded stimulus strengths, from below, at, and above the individually determined pain thresholds. Study participants reported each stimulus on a visual rating scale with respect to evoked sensation. Based on hemodynamic responses of all pooled stimuli, a cerebral network was identified that largely corresponds to the known lateral and medial nociceptive system. Further analysis of the five graded stimulus strengths revealed positive linear correlations for the anterior insula bilaterally, the contralateral (left) anterior mid-cingulate, as well as contralateral (left) pregenual cingulate cortices. Cerebral toothache intensity coding on a group level can thus be attributed to specific subregions within the cortical pain network.

Interindividual differences in the perception of dental stimulation and related brain activity

For identical diagnoses in the trigeminal innervation territory, individual differences have been clinically observed among the symptoms reported, such as dysesthesia and pain. Different subjective perceptions of unpleasantness and pain intensity may have different cortical substrates. The aim of this study was to identify brain areas in which activation depends on the subjective perception (intensity and unpleasantness) of electric dental stimulation. Electrical stimuli of increasing intensity were applied to maxillary canines in 14 healthy volunteers. Ratings for stimulus intensity and unpleasantness perceived across the stimulation session were reported postscan on 11-point numerical scales. The rating values were then included as covariates in the functional magnetic resonance imaging (fMRI) group analysis. Interindividual differences of intensity ratings were reflected in differential activity of the following brain areas: superior parietal lobule, superior temporal gyrus/anterior insula, inferior and middle temporal gyrus, lingual gyrus, anterior cingulate, and caudate nucleus. Differences related to unpleasantness ratings were reflected in the lingual gyrus. In conclusion, differences of perceived intensity between individuals are reflected in the differential activity of a set of brain areas distinct from those regions, reflecting rating differences of unpleasantness.

[Demodicosis in a Toggenburg goat]

This report describes the findings in a four-year-old Toggenburg goat with demodicosis. The skin had multifocal nodules, which were approximately 5 mm in diameter and contained thick yellow exsudate. Microscopic examination of the exsudate revealed numerous Demodex caprae. The goat was clipped and treated topically every five to seven days for a total of 12 treatments with a 1:100 dilution of amitraz (Ectodex, Hoechst Roussel Vet). The treatment resulted in a marked decrease in the number of skin nodules. However, new nodules appeared after treatment was discontinued and complete clinical cure was not achieved.

A chemiluminescence assay to detect antibodies to brain surface antigens in human sera

A chemiluminescence assay was developed based on the interaction between antibodies binding to the surface of living brain cells in culture and macrophages. Such interaction leads to production of reactive oxygen radicals which can be measured by a chemiluminescence assay. This assay was used to detect anti brain antibodies in serum samples from humans with various neurological diseases. Such antibody activity was found in a high proportion of these patients. Subsequent experiments with purified IgG fractions and corresponding F(ab')2 fragments showed that the observed reactions were highly specific. It was concluded that the chemiluminescence assay is a sensitive and useful technique to detect autoantibodies in neurological diseases.

Canine distemper virus increases procoagulant activity of macrophages

Inflammatory demyelination in canine distemper has been proposed to be due to a "bystander" mechanism, in which macrophages play an important role. In the present work we studied whether infection of macrophages by canine distemper virus (CDV) results in changes of macrophage functions, including Fc receptor-dependent and -independent phagocytosis, release of reactive oxygen species (ROS), and procoagulant activity (PCA). As a source of macrophages, dog bone marrow cells were seeded in teflon bags and grown for 1-2 weeks, at which time a marked enrichment of macrophages was noted. These cells were infected with the A75/17 strain of CDV. We could not detect any significant difference between uninfected and CDV-infected macrophages with respect to Fc receptor-dependent or -independent phagocytosis or with respect to the release of ROS. However, from Day 4 p.i. to the end of our observation period (10 days p.i.), PCA was up to 10-fold higher in CDV-infected unstimulated macrophage cultures than in uninfected unstimulated cultures of the same age. Increase in PCA was not due to the inoculation procedure by itself nor to components of the inoculum other than CDV; in particular, PCA was not due to contaminating endotoxin. Thus, several important macrophage functions do not appear to be impaired by CDV infection. The marked increase of macrophage PCA expression suggests that certain macrophage functions may even be enhanced as a result of infection. Such macrophage activation might contribute to the pathogenesis of the disease.

Two-dimensional gel electrophoresis of ribosomal proteins from streptomycin-sensitive and streptomycin-resistant mutants of Chlamydomonas reinhardi

Ribosomal proteins from three mutant strains of Chlamydomonas reinhardi were analysed and compared by one-dimensional and two-dimensional gel electrophoresis. One mutant was streptomycin-sensitive the other two were streptomycin-resistant, one with a Mendelian the other with a non-Mendelian pattern of inheritance. In the 30-S subunits of chloroplast ribosomes approximately 25 proteins are found and in the 50-S subunits 34 proteins. The 40-S subunits of cytoplasmic ribosomes contain about 31 proteins and the 60-S subunits 44 proteins. The molecular weights of most proteins in all subunits are in the range of 10 000 to 35 000. However, the 60-S subunits contain in addition a protein of molecular weight 50 000 and the 30-S subunits show 6-7 bands of molecular weights from 50 000 to 83 000. The proteins of the cytoplasmic 80-S ribosomes or of their subunits from all three mutants are electrophoretically identical. The proteins of the 70-S organellar ribosomes and both of their subunits show distinct differences between the three strains. Our results indicate that organellar ribosomal proteins are in part controlled by nuclear DNA and in part by organellar DNA.