[An unusual MRI observation of neurosarcoidosis]. / A propos d'une observation singulière de neurosarcoïdose.

Sarcoidosis is a multisystemic granulomatous disease, characterized by the formation of an inflammatory lesion, the noncaseating giant-cell granuloma. Neurosarcoidosis represents only 5% of cases, but this figure is probably an underestimation. Diagnosis is difficult because of its clinical and radiological polymorphism. Magnetic resonance imaging (MRI) represents the "gold standard" of central nervous system exploration. We report here on an atypical example of primary neurosarcoidosis, according to MRI semiology, with preferential involvement of the Virchow-Robin perivascular spaces.

[Rhinocerebral infections in immunosuppressed patients with hematological disorders]. / Infections rhinocérébrales chez l'immunodéprimé en hématologie.

Invasive rhinosinusitis, occurring almost exclusively in immunosuppressed patients, is defined by the presence of local inflammation with vascular and osseous necrosis with extensive soft tissue extension. Imaging and bacteriological and even histological (mycelial filaments) criteria have been established. Because it can evolve to death in patients with hematological disorders, accurate diagnosis is important but difficult to achieve due to the non-specific nature of signs and symptoms. Imaging plays an important role with CT of the paranasal sinuses and MR imaging of the brain for early diagnosis and treatment in order to improve prognosis. We will present the imaging features of three cases of rhinocerebral infections, with two cases of fungal infection and one case of invasive bacterial sinus infection.

Plumage colour mutations and melanins in the feathers of the Japanese quail: a first comparison.

The absorbance of melanin content from dorsal feathers was compared between wild-type Japanese quail and nine other quail plumage colours determined by single mutations in one of seven genes: extended brown (MC1R), yellow (ASIP), silver (MITF), lavender (MLPH), roux (TYRP1), imperfect albinism (SLC45A2) and rusty. As compared with wild-type quail, all mutations but extended brown decreased total melanins. The largest decrease was observed in quail with one of the dilution mutations at TYRP1, MLPH or SLCA45A2. No difference in eumelanins was found between the 10 plumage colours. Despite visible colour differences, homozygous and heterozygous mutants at MITF, or the two imperfect albino (white) and cinnamon (pale yellow) alleles at SLC45A2, could not be differentiated on the basis of melanins. In contrast, the two white phenotypes caused by mutations at MITF and SLC45A2, or the two reddish plumage colours caused by the roux and rusty non-allelic mutations had different total melanin contents. The results showed that rusty was not likely to be a dilution mutation.

[A rare cause of epigastric pain: isolated spontaneous dissection of the celiac artery, a case report]. / Une cause rare de douleur épigastrique: la dissection spontanée isolée du tronc coeliaque, à propos d'un cas.

Spontaneous dissection of visceral arteries, and more particularly of the celiac artery, is a rare event. We report an exceptional case of an isolated spontaneous dissection of the celiac artery which occurred in a 53-year-old man seen in an emergency setting for suspected acute pancreatitis. Computed tomography enabled the diagnosis, revealing spontaneous isolated dissection of the celiac artery, associated with a small aneurysmal dilatation of the artery. Based on a review of the literature and this clinical experience, we recall the contribution of computed tomography and 3D reconstructions to the diagnosis, the therapeutic strategy and the follow-up of spontaneous dissection of visceral arteries.

Delayed-type hypersensitivity response to KLH in F2 and backcrosses of two immune selected chicken lines: effect of immunisation and selection.

Cell-mediated immune response to keyhole limpet hemocyanin (KLH) was studied in 13 different progeny groups belonging to a second generation cross between two lines of White Leghorn previously selected for 10 generations for high antibody response to Newcastle disease vaccine (ND3) and high cell-mediated response to phytohemagglutinin (PHA) measured as wing web swelling. The cutaneous hypersensitivity response to KLH was assessed in KLH immunized and non-immunized birds. Wing thickness was measured at three time points: before the injection and 4 and 24 hours after the injection. The effect of previous immunization and genetic background was assessed. While no differences were present between progeny types or to a randomly bred control line at any of the three time points, significant differences were present between immunized and not immunized birds 24 hours after challenge. Results demonstrate that KLH immunized birds perform better and that the previous selection and crossbreeding scheme has not influenced the intensity of the skin swelling response to KLH. Apparently, neither selection for antibody responsiveness to ND3 nor selection for enhanced responsiveness to a T cell mitogen affected delayed-type hypersensitivity (DTH) to the Th 2 antigen KLH. These results may serve to facilitate further selection based on independent immune parameters.

Circulating corticosterone reaction to restraint and adrenocorticotropin hormone administration in white leghorns selected for immune response traits.

Corticosterone plasma concentration was measured in a random-bred control line and in 3 White Leghorn chicken lines previously selected over 9 generations for 3 different in vivo immune responses: high antibody response to Newcastle disease virus vaccine 3 wk after vaccination (ND3), high cell-mediated immune response (response to phytohemagglutinin, PHA), and high phagocytic activity measured as carbon clearance (CC). The objective of the study was to estimate if selection on immune response had an effect on the response to stress assessed by measures of corticosterone concentration before and after physical stress or adrenocorticotropin hormone injection and if the effect was dependent on the immune response trait that had been selected for, by joint analyses of immune responses and concentrations. The mean values of plasma corticosterone measures did not differ between lines, indicating that selection for different high immune responses had little effect on response to stress. Within line, however, significant negative correlations (-0.46

Association of a single-nucleotide substitution in TYRP1 with roux in Japanese quail (Coturnix japonica).

We investigated TYRP1 as a candidate locus for the recessive, sex-linked roux (br(r)) phenotype in Japanese quail. A screen of the entire coding sequence of TYRP1 in roux and wild-type quail revealed a non-synonymous T-to-C substitution in exon 3, leading to a Phe282Ser mutation. This was perfectly associated with plumage phenotype: all roux birds were homozygous for Ser282. Co-segregation of the Phe282Ser mutation with the roux phenotype was confirmed in three br(r)/BR+ x br(r)/- backcrosses. We found no significant difference in TYRP1 expression between roux and wild-type birds, suggesting that this association is not due to linkage disequilibrium with an unknown regulatory mutation. In addition, the Phe282 amino acid appears to be of functional significance, as it is highly conserved across the vertebrates. This is the first demonstration that TYRP1 has a role in pigmentation in birds.

Analysis of polymorphisms in the insulin-like growth factor 1 receptor (IGF1R) gene from Japanese quail selected for body weight.

Insulin-like growth factor 1 receptor (IGF1R) is essential for the signalling of growth. In this study, we performed single nucleotide polymorphism (SNP) detection in the Japanese quail IGF1R coding region and an association study between SNPs and body weight in two lines (SS and LL) selected for large and small body weight. Of 21 SNPs obtained, a SNP at position AB292766:c.2293G>A led to the replacement of a valine with an isoleucine (V765I). The two lines were fixed for alternate alleles, with allele encoding valine fixed in the LL line. A significant effect of the SNP genotype was found on 10-week body weight (P < 0.01) and on 4- to 10-week and 6- to 10-week average daily gain (P < 0.05) in the F(2) family obtained from lines LL and SS. In six populations maintained in Japan or France, the frequency of allele encoding valine was higher than the allele encoding isoleucine.

Development and performances of a Japanese quail line homozygous for the diabetes insipidus (di) mutation.

A strain of Japanese quail with the polyuria disorder (excessive urination) was developed from founders that regurgitated water spontaneously. A back-cross with a nonpolyuric quail line showed that the polyuric strain was fixed for an autosomal recessive mutation that also induced polydipsia (excessive drinking). Plasma levels and brain mRNA contents for avian Arg vasotocin were little affected by the mutation, but plasma avian Arg vasotocin was 13-fold higher and brain mRNA contents were significantly increased in both normal and mutant quail following a 24-h water deprivation. Affected and normal birds had similar performance traits (egg production and quality, feed intake, and gross carcass traits), but residual feed consumption was higher in polydipsic males. These results are consistent with the hypothesis that this strain was fixed for a mutation similar to the di gene described in the chicken and which induces nephrogenic diabetes insipidus. This new strain of Japanese quail might constitute a convenient model for the analysis of the underlying mechanisms of the disorder in birds and for comparative study with mammals.

Effects of the dominant lethal yellow mutation on reproduction, growth, feed consumption, body temperature, and body composition of the Japanese quail.

Wild-type Japanese quail were compared with full-sibs with a yellow plumage color determined by an autosomal dominant mutation (Y), which is lethal when homozygous. These quail have wheat-straw yellow-colored feathers. Early growth was slower in yellow quail that had 2.4% lower BW than wild-type quail (149.3 g vs. 153.0 g) at 28 d of age. The BW, however, was similar for yellow and wild-type males at 35 d, and it remained so throughout the last part of the growth of the quail monitored until the age of 120 d, as indicated by the very close parameters of the monomolecular growth curve [BW= A - B exp(-kt)] obtained for the 2 groups. Yellow plumage color was also associated with a more difficult adaptation to housing (measured by temporary BW loss) in individual cages and to a significantly 0.2 degrees C lower body temperature at 42 d, but feed consumption and residual feed intake were similar for the 2 plumage color phenotypes. Breast and liver weights were similar in the 2 groups, but abdominal fat was 24% higher (4.66 vs. 3.76 g) in yellow quail. There is some association between the correlated effects of the Y gene in quail and those of the lethal mutation A(y) at the agouti locus in the mouse.

Antibody responses to keyhole limpet hemocyanin, lipopolysaccharide, and Newcastle Disease virus vaccine in F2 and backcrosses of white Leghorn lines selected for two different immune response traits.

Planned crosses were designed to produce an F(2) and 2 backcross populations from 2 lines of White Leghorn chickens previously selected over 10 generations for 2 different in vivo immune responses. The selection criteria applied on the 2 grandparental lines were as follows: high antibody response to Newcastle disease virus vaccine 3 wk after vaccination (ND3) and high cell-mediated immune response [response to phytohemagglutinin]. Furthermore a control line was kept by random breeding. The objective of the study was to estimate if the 2 selection criteria applied on the pure lines had changed the level of and type of immune (humoral) response to a new antigen, keyhole limpet hemocyanin (KLH), in the various second-generation progeny groups. In addition, correlations between parameters of acquired and innate immunity were tested. Primary total (IgT) and isotype-specific (IgG and IgM) antibody response to KLH 1 wk after immunization and levels of natural antibodies (NAB) binding to Salmonella enteriditis-derived lipopolysaccharide (LPS) were measured. Although no differences were present between IgM and IgG antibodies to KLH and the phytohemagglutinin skin-swelling response, significant differences were present between all the progeny groups for IgT to KLH and ND3 and NAB binding to LPS. The mean values for IgT to ND3 and KLH were significantly different between the crosses using the selected lines compared with the control line, indicating a contribution of the previous selection. In addition, a sex effect was found for IgM to KLH and NAB to LPS, for which females had a higher response than males in both cases. No interaction between progeny type and sex was found. Furthermore, significant positive correlations were found between NAB to LPS and specific antibody titers to KLH. Finally, the results of the present study demonstrated an interaction between innate and acquired immunity under this strategy of selection and crossbreeding and confirmed the effect of selection on general immune response to a new antigen in second-generation crosses.

An alternative experimental case-control design for genetic association studies on bovine mastitis.

The possibility of using genetic control strategies to increase disease resistance to infectious diseases relies on the identification of markers to include in the breeding plans. Possible incomplete exposure of mastitis-free (control) animals, however, is a major issue to find relevant markers in genetic association studies for infectious diseases. Usually, designs based on elite dairy sires are used in association studies, but an epidemiological case-control strategy, based on cows repeatedly field-tested could be an alternative for disease traits. To test this hypothesis, genetic association results obtained in the present work from a cohort of Italian Holstein cows tested for mastitis over time were compared with those from a previous genome-wide scan on Italian Holstein sires genotyped with 50k single nucleotide polymorphisms for de-regressed estimated breeding values for somatic cell counts (SCCs) on Bos taurus autosome (BTA6) and BTA14. A total of 1121 cows were selected for the case-control approach (cases=550, controls=571), on a combination of herd level of SCC incidence and of within herd individual level of SCC. The association study was conducted on nine previously identified markers, six on BTA6 and four on BTA14, using the R statistical environment with the 'qtscore' function of the GenABEL package, on high/low adjusted linear score as a binomial trait. The results obtained in the cow cohort selected on epidemiological information were in agreement with those obtained from the previous sire genome-wide association study (GWAS). Six out of the nine markers showed significant association, four on BTA14 (rs109146371, rs109234250, rs109421300, rs109162116) and two on BTA6 (rs110527224 and rs42766480). Most importantly, using mastitis as a case study, the current work further validated the alternative use of historical field disease data in case-control designs for genetic analysis of infectious diseases in livestock.

A simulation study of truncation selection for a quantitative trait opposed by natural selection.

A quantitative character controlled at one locus with two alleles was submitted to artificial (mass) selection and to three modes of opposing natural selection (directional selection, overdominance and underdominance) in a large random-mating population. The selection response and the limits of the selective process were studied by deterministic simulation. The lifetime of the process was generally between 20 and 100 generations and did not appear to depend on the mode of natural selection. However, depending on the values of the parameters (initial gene frequency, selection intensity, ratio of the effect of the gene to the environmental standard deviation, fitness values) the following outcomes of selection were observed: fixation of the allele favored by artificial selection, stable nontrivial equilibrium, unstable equilibrium and loss of the allele favored by artificial selection. Finally, the results of the simulation were compared to the results of selection experiments.

Natural selection opposing artificial selection: a two-locus deterministic simulation.

A two-locus, two-allele metric trait was submitted to artificial truncation selection and to three types of opposing natural selection (two-locus extensions of directional selection, overdominance and underdominance) by numerical simulation in a large random-mating population. Limits to selection were generally reached by generation 100. Intermediate selection plateaus were found, with minor genes, for all three modes of opposing natural selection, but they were least frequent with underdominance. Multiple outcomes were common. In particular, fixation of the genotype favored by artificial selection was often associated with fixation of another genotype and/or with a central equilibrium; the end point actually reached depended on the genetic starting point of the simulation. In general, when the alleles favored by truncation selection were combined (positive linkage disequilibrium) in the base population, or when the trait was determined by major genes, artificial selection would prevail. Limitations inherent to this type of work are discussed, and possible avenues for further work on the antagonism between artificial and natural selection are proposed.

Changes in retinal dopaminergic cells and dopamine rhythmic metabolism during the development of a glaucoma-like disorder in quails.

PURPOSE: To examine the possible correlation between a dysfunction of the daily rhythm of retinal dopamine (DA) and the development of a glaucoma-like disorder in an animal model, the al mutant quail (Coturnix coturnix japonica). METHODS: The morphology and density of DA-containing cells labeled immunohistochemically with an anti-tyrosine hydroxylase (TH) antibody were correlated with the diurnal and nocturnal contents of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) determined by high-pressure liquid chromatography with electrochemical detection. RESULTS: The number of TH-immunoreactive cells was lower than normal in mutant quails suffering from the disorder. There were considerably fewer cells in the central retina, and the DA metabolism was reduced in parallel. The nocturnal DA content was lower than the diurnal level in normal quails, but there was no such circadian fluctuation in mutant quails. CONCLUSIONS: This glaucoma-like disorder in quails is correlated with the degeneration of DA-containing amacrine cells and a dysfunction of the circadian rhythmicity of DA synthesis.

Retinal TUNEL-positive cells and high glutamate levels in vitreous humor of mutant quail with a glaucoma-like disorder.

PURPOSE: To investigate whether retinal cell death observed in an avian glaucoma-like disorder occurs by apoptosis and whether an increase in excitotoxic amino acid concentration in the vitreous humor is associated temporally with cell death in the retina. METHODS: Presumptive retinal apoptotic nuclei were identified by histochemical detection of DNA fragmentation (by TdT-dUTP terminal nick-end labeling [TUNEL]), and vitreal concentrations of glutamate and several other amino acids were determined by high-pressure liquid chromatography with fluorometric detection in the al mutant quail (Coturnix coturnix japonica) in which a glaucoma-like disorder develops spontaneously. RESULTS: TUNEL-labeled nuclei were located mostly in the ganglion cell layer (GCL) in the retina of mutant quails 3 months after hatching. However, labeled nuclei were also observed in the inner and outer nuclear layers. At 7 months, most TUNEL-positive nuclei were detected in the inner nuclear layer, whereas labeled cells in the GCL were reduced in number. No TUNEL-labeled nuclei were detected in the retina of control quails at any age. Vitreal concentrations of glutamate and aspartate were significantly increased in 1-month-old mutant quails compared with control animals. Concentrations decreased at 3 months, and no significant differences were observed between strains at 7 months. CONCLUSIONS: Presumptive apoptotic cell death is detected from 3 months after hatching in mutant quails and is not restricted to retinal ganglion cells. Cell death appears just after a significant increase in excitotoxic amino acid concentrations in the vitreous humor, suggesting a correlation between both events.

Seasonal changes in breeding activity, testicular size, testosterone concentration and seminal characteristics in rams with long or short breeding season.

Breeding activity (libido), testicular size, testosterone levels and seminal characteristics of 10 DLS adult rams (a population of 1/2 Dorset, 1/4 Leicester and 1/4 Suffolk selected for extended breeding season) were compared with those of 10 adult Suffolk rams. The study lasted 18 mo during which the data were recorded over 30 collection periods. All characteristics varied significantly with the season of the year, being lowest during the summer and highest during the fall. Suffolk rams had higher libido but lower testosterone levels than the DLS rams throughout the study. Testosterone increased earlier and decreased later in the breeding season in DLS compared with Suffolk rams, the interaction breed X period being significant. Testosterone concentration was highly associated with testicular size and libido, accounting for 65 and 28% of the variation in the Suffolk and 37 and 18% in the DLS rams, respectively. Seminal output and quality (motility and percentage of live spermatozoa) were highest in October and November and lowest in April and May. Rams within breeds differed significantly in the seminal characteristics studied. Results of the study showed that selecting the DLS ewes for extended breeding season may have altered the reproductive performance of the rams of that breed.

Computer simulation model of swine production systems: I. Modeling the growth of young pigs.

Theoretical concepts and relationships were used to develop a deterministic pig growth model. The model predicts, in a continuous form, growth and body composition of boars, barrows, and gilts according to genotype, diet, and management conditions. The model is aggregated at the whole-animal level with three main elements of body composition; total body DNA, total body protein mass (PT), and total body mass of lipids, with PT determining the secondary elements of ash and moisture. The primary factors regulating growth were associated with cellular hyperplasia and hypertrophy in agreement with the basic concepts described by Baldwin and Black (1979). Differential equations representing DNA accretion and protein synthesis and degradation were adapted from Oltjen et al. (1985). Normal pig protein growth was characterized from published data. Body PT was used to reflect several metabolic activities related to animal size and age, as in some prior models. Dietary energy and protein were used in sequence until requirements are satisfied, first for maintenance, then for protein growth, and finally for fat deposition. A comparison between experimental and simulated results illustrates that the model may simulate growth and body composition of young pigs adequately.