Histochemical analyses of anti-microbial substances in canine perianal skin with special reference to glandular structures

Circumanal glands are prominent features of the canine perianal skin, which are often located near to the sebaceous glands and apocrine glands. As the functional relevance of circumanal glands is yet unknown, we studied the localisation of sialic acids and anti-microbial substances (lysozyme, immunoglobulin A, lactoferrin, β-defensin) in these glandular structures by lectin histochemistry and immunohistochemistry. The glands exhibited a number of sialic acids that were linked to α2-6Gal/GalNAc and α2-3Galβ1-4GlcNAc. Additionally, lysozyme, lactoferrin and β-defensin could be demonstrated in the three types of skin glands, whereas IgA was only detectable in the apocrine glands. The results of the study suggest the specific significance of the circumanal glands. Independent of a certain endocrine role, their products may mainly function as protective agents to preserve the integrity of the anal region, considering that sialic acids and anti-microbial substances are important in defence mechanisms.

First measurement of chiral dynamics in π- γ → π- π- π+

The COMPASS Collaboration at CERN has investigated the π- γ → π- π- π+ reaction at center-of-momentum energy below five pion masses, sqrt[s]<5m(π), embedded in the Primakoff reaction of 190 GeV pions impinging on a lead target. Exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, t'<0.001  GeV2/c2. Using partial-wave analysis techniques, the scattering intensity of Coulomb production described in terms of chiral dynamics and its dependence on the 3π-invariant mass m(3π)=sqrt[s] were extracted. The absolute cross section was determined in seven bins of sqrt[s] with an overall precision of 20%. At leading order, the result is found to be in good agreement with the prediction of chiral perturbation theory over the whole energy range investigated.

Basics of skin structure and function in elasmobranchs: a review

In contrast to the bony fishes, particularly the teleosts, the integument of elasmobranchs is rather unknown. Therefore, a description of the basic structural and functional features of shark and ray skin is given, based on a review of the literature and published or unpublished findings of the authors. The latter aspect makes it possible to document in more detail the specific structure of the skin layers regarding, particularly, the epidermis and its cell spectrum, the more or less robust dermis with its specific features, the very special scales with their derivates and the sophisticated sensoric integumental equipment. As far as possible, all important structures are discussed including their typical biological functions and results from applied scientific work. To some extent the information given is evaluated as compared with the much broader knowledge from the Osteichthyes.

Histochemical localization of sialic acids and antimicrobial substances in eccrine glands of porcine snout skin

The distribution of sialic acids and antimicrobial products (lysozyme, IgA, lactoferrin, β-defensin 2) as well as Rab3D in the eccrine glands of porcine snout skin was studied by sialoglycoconjugate histochemistry and immunohistochemistry. The secretory epithelium consisted of two types of secretory cells: dark and clear cells. The dark cells exhibited considerable amounts of sialoglycoconjugates, which included O-acetylated sialic acids, whereas sialic acids in the sequence Siaα-2-3Gal1-4GlcNAc were confined to some of the dark cells. All antimicrobial substances and Rab3D were demonstrated to be also mainly present in some of the dark cells. Additionally, in the cytological and cytochemical features, the different characteristics were observed among the dark cells. The results obtained are discussed with regard to the functional significance of the eccrine glands. The secretory products elaborated by this gland type may function as protective agents in order to preserve the skin integrity of the snout region, considering that sialic acids and antimicrobial substances are important in general defense mechanisms.

Histochemical properties of sialic acids and antimicrobial substances in canine anal glands

The functional properties of sialic acids appear to be manifold. Additionally, antimicrobial substances serve as a non-specific defense against microorganisms. In this study, therefore, the localization of sialic acids and antimicrobial substances in the anal glands of dog was studied by sialoglycoconjugate histochemistry and immunohistochemistry. The secretory epithelium, luminal secretions and excretory ducts exhibited high levels of sialoglycoconjugates that terminated in Siaα2-6Gal/GalNAc or Siaα2-3Gal1-4GlcNAc. Additionally, O-acetylated sialic acids were detectable in these glandular structures. Antimicrobial substances, such as lysozyme, immunoglobulin A (IgA), lactoferrin and the peptide group of β-defensins, were also demonstrated as products of the anal glands. The results obtained are discussed with regard to the functional significance of the anal glands. These secretory products may create a defensive barrier against microbial invasion at the anal mucosa.

Global VGIIa isolates are of comparable virulence to the major fatal Cryptococcus gattii Vancouver Island outbreak genotype

The ongoing cryptococcosis outbreak on Vancouver Island, BC, Canada, is caused by two VGII sub-genotypes of the primary pathogen, Cryptococcus gattii: VGIIa isolates predominate, whereas VGIIb isolates are rare. Although higher virulence of the VGIIa genotype has been proposed, an unresolved key question is whether VGIIa isolates from other regions are also more virulent than VGIIb isolates. We report the relationship between genotype and virulence for a global collection of C. gattii VGIIa and VGIIb isolates (from Australia, Argentina, Brazil, Canada, Thailand and the USA). In vitro and in vivo virulence studies were conducted. At 37°C, growth [at 18 h: 0.2 optical density (OD) difference, p 0.026; at 36 h: 0.6 OD difference, p 0.036) and mean melanin production (OD = 0.25 vs. OD = 0.15, p 0.059] of VGIIa isolates was greater than that of VGIIb isolates. The inhibitory effect of high temperature on melanin production of VGIIa isolates was less than that of VGIIb isolates (OD = 0.36 vs. OD = 0.69; p 0.001). Capsule production at 37°C of VGIIa isolates was less than that of VGIIb isolates. All VGIIa isolates were fertile, whereas only 17% of VGIIb isolates were fertile (p <0.001). In vivo virulence studies using the BALB/c mice nasal inhalation model revealed that VGIIa isolates were more virulent than VGIIb isolates (p <0.001) independent of their clinical (p 0.003) or environmental origin (p <0.001). This study established a clear association between genotype and virulence of the primary fungal pathogen, C. gattii.

Lectin histochemistry of the temporal gland of the African elephant (Loxodonta africana)

The study demonstrates the free sugar spectrum of the secretion of the tubuloaveolar temporal gland of the African elephant (Loxodonta africana), using lectin histochemistry. In the elephant, the spectrum contained, besides strongly varying amounts of α-D-mannose, very remarkable reactions for α-D-galactose and to a certain extent also for α-D-N-acetyl-galactosamine or a/ß-D-N-acetylglucosamine. This is in contrast to the free sugar spectrum of the secretion of the mammalian apocrine tubular skin glands. Considering also that the production of any water binding mucus seems to be negligible, the variations of the free sugar contents found probably originate from another important task of the secretory cells of the temporal gland. This means that our findings corroborate the view of highly active acquired immunity by an intensive processing and presenting of lipid antigens by dendritic cells (APC), in particular of the CD1 family.

Doppler coherence imaging and tomography of flows in tokamak plasmas (invited)

This article describes the results of spatial heterodyne Doppler "coherence imaging" of carbon ion flows in the divertor region of the DIII-D tokamak. Spatially encoded interferometric projections of doubly ionized carbon emission at 465 nm have been demodulated and tomographically inverted to obtain the spatial distribution of the carbon ion parallel flow and emissivity. The operating principles of the new instruments are described, and the link between measured properties and line integrals of the flow field are established. An iterative simultaneous arithmetic reconstruction procedure is applied to invert the interferometric phase shift projections, and the reconstructed parallel flow field amplitudes are found to be in reasonable agreement with UEDGE modeling.

Observation of a J(PC)=1-+ exotic resonance in diffractive dissociation of 190 GeV/c π- into π- π- π+

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190  GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1  GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66  GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0))  MeV/c2 and a width of (269±21(-64)(+42))  MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.

Changes in skin mucus of common carp, Cyprinus carpio L., after exposure to water with a high bacterial load

Water in aquaculture systems may contain a high load of microorganisms. Reduction in overall bacterial tank water load improves fish health and growth parameters. In this study, the effect of an increase of overall bacterial load in tank water on carp skin mucus was assessed. Intracellular and released high molecular weight glycoproteins (HMGs) of carp skin mucus were analysed for changes using histological, histochemical and biochemical techniques. Increase of bacterial load did not induce obvious clinical responses in carp, but the skin of exposed carp responded quickly. The amount of skin mucus HMGs isolated increased as well as their total glycosylation. An increased goblet cell number was observed for all carbohydrate stainings, but most clearly for acidic glycoconjugates. A change in the terminal presence of some sugars was also seen. After the initial response of carp, an adaptation to the higher bacterial load in the water appeared to occur as mucins had a higher glycosylation. The changes observed suggest that these skin mucus adaptations are part of a primary defence mechanism of mucosal epithelia, even at a low pathogenic pressure.

Genotyping of Mexican Cryptococcus neoformans and C. gattii isolates by PCR-fingerprinting

Cryptococcosis in México is caused by both species of the Cryptococcus species complex i.e., Cryptococcus neoformans and C. gattii. The current study was aimed to determine genetic variability of 72 Mexican clinical isolates using PCR-fingerprinting with the primer M13. PCR fingerprinting revealed 55 VNI, five VNII, three VNIII, one VNIV, two VGI, two VGII, two VGIII and two VGIV isolates among those studied. The results show that most cryptococcosis cases in México are AIDS related and are caused by C. neoformans var. grubii, genotypes VNI and VNII. In addition this study revealed for the first time the presence of genotypes VNIV and VGII among Mexican clinical isolates. The present data show that all genotypes that have been described for the Cryptococcus species complex are found in México, indicating a much wider geographic distribution of genotypes than previously reported. The molecular analysis of Mexican cryptococcal isolates generated PCR-fingerprinting patterns which will provide references for future typing studies to allow the integration of Mexican cryptococcal genotypes into the ongoing global genotyping study of the Cryptococcus species complex.

A note on langerhans cells in the oesophagus epithelium of domesticated mammals

Using the zinc-iodide osmium tetroxide (ZIO) method, TEM and immunohistochemistry (for CD1a and langerin), the study demonstrates Langerhans cells in the oesophageal epithelium of domesticated mammals (herbivores: horse, cattle, goat; omnivores: pig, dog, laboratory rat; carnivores: cat), although with variations between the species. The ZIO method and TEM showed this cell type in the cat and, sporadically, in the horse; CD1a (+) Langerhans cells were demonstrated in the ovine, porcine and murine oesophagus. Positive staining for langerin was detected in single cells of the caprine, canine, murine and feline oesophagus and more distinct in almost all the cell layers of the equine and porcine oesophagus epithelium. The findings are discussed comparing specifically the results for CD1a and langerin, whereby the latter C-type lectin may be of importance in species with a rather thick oesophagus epithelium, such as that present in the plantivorous and most of the omnivorous animals, where antigenic pressure is reduced.