Host immune genetic variations influence the risk of developing acute myeloid leukaemia: results from the NuCLEAR consortium.

The purpose of this study was to conduct a two-stage case control association study including 654 acute myeloid leukaemia (AML) patients and 3477 controls ascertained through the NuCLEAR consortium to evaluate the effect of 27 immune-related single nucleotide polymorphisms (SNPs) on AML risk. In a pooled analysis of cohort studies, we found that carriers of the IL13rs1295686A/A genotype had an increased risk of AML (PCorr = 0.0144) whereas carriers of the VEGFArs25648T allele had a decreased risk of developing the disease (PCorr = 0.00086). In addition, we found an association of the IL8rs2227307 SNP with a decreased risk of developing AML that remained marginally significant after multiple testing (PCorr = 0.072). Functional experiments suggested that the effect of the IL13rs1295686 SNP on AML risk might be explained by its role in regulating IL1Ra secretion that modulates AML blast proliferation. Likewise, the protective effect of the IL8rs2227307 SNP might be mediated by TLR2-mediated immune responses that affect AML blast viability, proliferation and chemorresistance. Despite the potential interest of these results, additional functional studies are still warranted to unravel the mechanisms by which these variants modulate the risk of AML. These findings suggested that IL13, VEGFA and IL8 SNPs play a role in modulating AML risk.

Isolation and phylogenetic characterization of Streptococcus halichoeri from a European badger (Meles meles) with pyogranulomatous pleuropneumonia.

Clinical and pathological studies in European badgers (Meles meles) are limited. Badgers play a significant role in the epidemiology of bovine tuberculosis (TB) in some countries and an accurate diagnosis is needed for this infection. However, the lesions of bovine TB are similar to those associated with other pathogens, making pathological diagnosis difficult. In the present study, Streptococcus halichoeri was isolated from a European badger with pyogranulomatous pleuropneumonia and suspected of having tuberculosis. TB and other pathogens able to induce similar lesions were ruled out. Comparative 16S rRNA and rpoB gene sequencing studies showed an identity of 99.51% and 98.28%, respectively, with S. halichoeri. This report represents the third description of this bacterium and the first in an animal species other than the grey seal (Halichoerus grypus). It also shows that S. halichoeri can be associated with a pathological process characterized by granulomatous inflammation and resembling tuberculosis.

Nerve compression syndromes of the hand and forearm associated with tumours of non-neural origin and tumour-like lesions.

Nerve compression syndromes caused by non-neural tumours or tumour-like lesions are rare. We retrospectively reviewed 541 consecutive patients operated on by the same surgeon to study nerve compression syndromes in the forearm and hand. There were 414 due to nerve compression and 127 caused by tumours. Twenty-two patients showed compression neuropathy associated with 17 tumours and six tumour-like lesions, with 13 different pathological types. The most common types were fatty and vascular tumours. Twenty-one tumours were extraneural and one was intraneural. The median nerve was affected in nine cases, the ulnar nerve or the dorsal sensory branch of the ulnar nerve in five cases, the posterior interosseous nerve or the superficial radial branch in four cases and the common digital nerves in two cases. There was a concomitant involvement of the median and ulnar nerves in two other patients. Clinically, there were eight different compression neuropathies, of which the most frequent was the carpal tunnel syndrome. The postoperative histology was consistent with preoperative magnetic resonance imaging findings in the vascular and fatty tumours. Pain disappeared completely in 15 out of 16 patients with preoperative pain. All patients had preoperative paraesthesia, which persisted after tumour excision in three patients: attenuated in two patients and unchanged in one. In three patients, we did not observe any change in paresis or amyotrophy. The mean postoperative follow-up was 31 months, without tumour recurrence. The quick Disabilities of the Arm, Shoulder and Hand (DASH) score went from 49.9 points preoperatively to 10.2 points after surgery.

ESX-1-induced apoptosis is involved in cell-to-cell spread of Mycobacterium tuberculosis.

Apoptosis modulation is a procedure amply utilized by intracellular pathogens to favour the outcome of the infection. Nevertheless, the role of apoptosis during infection with Mycobacterium tuberculosis, the causative agent of human tuberculosis, is subject of an intense debate and still remains unclear. In this work, we describe that apoptosis induction in host cells is clearly restricted to virulent M. tuberculosis strains, and is associated with the capacity of the mycobacteria to secrete the 6 kDa early secreted antigenic target ESAT-6 bothunder in vitro and in vivo conditions. Remarkably, only apoptosis-inducing strains are able to propagate infection into new cells, suggesting that apoptosis is used by M. tuberculosis as a colonization mechanism. Finally, we demonstrate that in vitro modulation of apoptosis affects mycobacterial cell-to-cell spread capacity, establishing an unambiguous relationship between apoptosis and propagation of M. tuberculosis. Our data further indicate that BCG and MTBVAC vaccines are inefficient in inducing apoptosis and colonizing new cells, correlating with the strong attenuation profile of these strains previously observed in vitro and in vivo.

Molecular characterization and phylogenetic study of Maedi Visna and Caprine Arthritis Encephalitis viral sequences in sheep and goats from Spain.

Small ruminant lentiviruses (SRLV) are widely spread in many countries, including Spain. However, little is known about the genetic characteristics of Spanish goat and sheep SRLV. In this study, segments from three genomic regions (pol, gag-p25 and LTR) were amplified using DNA isolated from three Spanish autochthonous sheep (one) and goats (two). Animals (one per flock) belonged to distantly located, single-species flocks (goat or sheep). Sequence analysis showed conservation of regions that are putatively relevant to viral survival. Sequences of Spanish goat and sheep SRLV were allocated into phylogenetic trees (phylograms) with known SRLV groups. The phylograms corresponding to the pol, gag-p25 and LTR regions analyzed presented a compatible topology. This showed that Spanish caprine and ovine SRLV sequences belonged to the A or D phylogenetic groups and were closer to sheep SRLV prototypes (A1 group) than to goat SRLV prototypes (B or C groups), according to the current classification [Shah, C., Boni, J., Huder, J.B., Vogt, H.R., Muhlherr, J., Zanoni, R., Miserez, R., Lutz, H., Schupbach, J., 2004a. Phylogenetic analysis and reclassification of caprine and ovine lentiviruses based on 104 new isolates: evidence for regular sheep-to-goat transmission and worldwide propagation through livestock trade. Virology 319 (1), 12-26]. It was not possible to amplify in the three genetic regions the expected fragment in additional Spanish caprine and ovine SRLV proviral DNA sequences with the PCR primers used. This suggests that there is heterogeneity at the primer binding site among Spanish SRLV sequences. It also illustrates the need to develop diagnostic tests that are sensitive in local breeds.

A new sensitive serological assay for detection of lentivirus infections in small ruminants.

Lentivirus infections in small ruminants represent an economic problem affecting several European countries with important sheep-breeding industries. Programs for control and eradication of these infections are being initiated and require reliable screening assays. This communication describes the construction and evaluation of a new serological screening enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to maedi-visna virus (MVV) in sheep and to caprine arthritis encephalitis virus (CAEV) in goats. The solid phase is sensitized with a combination of the major core protein p25 of MVV produced in Escherichia coli and a peptide derived from the immunodominant region of the viral transmembrane protein gp46. The peptide carries an N-terminal biotin residue and is complexed with streptavidin prior to being coated. The new assay was evaluated with 2,336 sheep serum samples from different European countries with large differences in the levels of prevalence of MVV infections, and the results have been compared to those of the standard agar gel immunodiffusion test. Discrepant samples were analyzed by Western blotting with viral lysate, and most sera could be classified unambiguously. The estimated overall sensitivity of the new ELISA was 99.4% (95% confidence interval [CI], 98.4 to 99. 8%) and the specificity was 99.3% (95% CI, 98.7 to 99.6%). A limited set of goat sera (n = 212) was also analyzed, with similar results. These data indicate that the new assay is a reliable tool that can be used in control and eradication programs for small ruminant lentivirus infections.

Description and classification of different types of lesion associated with natural paratuberculosis infection in sheep.

Paratuberculosis lesions in naturally infected sheep were classified histologically. Adult sheep (n = 166) culled for various reasons, from four flocks in which clinical cases of the disease had occurred, were studied. Eight-two sheep (49.4%) showed lesions that could be divided into three main categories. Type 1 lesions, found in 24.1% of these animals, consisted of small granulomata formed by macrophages and were located exclusively in the ileocaecal Peyer's patch. In type 2 lesions, found in 4.8% of the sheep, granulomata were also observed in the mucosa associated with Peyer's patches. Type 3 lesions were characterized by granulomata in areas of the mucosa associated with, and also distinct from, the Peyer's patches. Three subtypes of type 3 lesions were recognized. In subtype 3a, found in 4.2% of the sheep, multifocal granulomata appeared in different areas of the lamina propria; they were not apparently associated with lymphoid tissue, and neither did they modify the morphology of the affected areas. Subtype 3b, found in 13.9% of animals, consisted of large numbers of macrophages, widespread in the lamina propria; in subtype 3c (2.4% of sheep) lymphocytes were the main inflammatory cell, with some macrophages scattered amongst them. In subtypes 3a and b, villi were distended and the mucosa appeared thickened. Mycobacteria could be demonstrated in tissue sections from all the samples with subtype 3b lesions and in almost all of those with type 2 and 3a lesions; these organisms were absent or sparse, however, in type 1 and 3c lesions. Macroscopical lesions were clearly visible only in sheep with type 3b and 3c lesions. Mycobacterium paratuberculosis was cultured from all the animals with type 3 lesions, from 87.5% of those with type 2 lesions, and from 47.5% of those with type 1. Type 3b lesions resembled the "borderline-lepromatous" form of mycobacterial lesions, whereas type 3c lesions resembled the "borderline-tuberculoid" form. The relationship between intestinal lymphoid tissue and paratuberculosis lesions is discussed, and the diagnostic importance of histological examination of the ileocaecal valve emphasized.

Experimental infection of vaccinated and non-vaccinated lambs with Mycobacterium paratuberculosis.

A study of the pathogenesis of paratuberculosis and the effects of vaccination was carried out on 17 Rasa lambs, allocated to four groups. Vaccination seemed to accelerate the progress of the infection, and led quickly to healing. The only site of early lesions was the interfollicular areas in the Peyer's patches. This would suggest an explanation both for the location of paratuberculous lesions in the ileum in clinical cases, and for the lower susceptibility to infection of adult animals, in which the intestinal organized lymphoid tissue is greatly diminished. Thus, a critical role of the Peyer's patch in the establishment of M. paratuberculosis infection is suspected.

Immunocytochemical detection of amylase, carboxypeptidase A, carcinoembryonic antigen and alpha 1-antitrypsin in carcinomas of the exocrine pancreas of the dog.

The immunocytochemical detection of amylase, carboxypeptidase A, alpha 1-antitrypsin, carcinoembryonic antigen (CEA) and keratin in normal canine pancreatic tissue and in carcinomas of the exocrine pancreas of the dog is described. In the normal pancreas, the acinar cells contain amylase, carboxypeptidase and alpha 1-antitrypsin. The pancreatic ducts react with the antikeratin antibody. Twelve out of 14 pancreatic exocrine carcinomas showed immunoreaction with antiamylase antibody, and 10 with anticarboxypeptidase antibody. Five neoplasms reacted with anti-CEA antibody and three with the anti-alpha 1-antitrypsin antibody. It was not possible to find any systematic difference in the immunocytochemical profiles of acinar, tubular and undifferentiated carcinomas. These results indicate that immunocytochemical marking of amylase and carboxypeptidase is of value in the diagnosis of pancreatic neoplasms in the dog, especially if metastasis is the only material available for study and the tumour does not show any diagnostic feature on routine light microscope preparations.