Dermal microdialysis in the dog: in vivo assessment of the effect of cyclosporin A on cutaneous histamine and prostaglandin D2 release

Dermal microdialysis, a relatively noninvasive technique, allows investigation of the changes in cellular mediators released during cutaneous allergic responses. This technique was used to evaluate the effect of cyclosporin A, an immunosuppressive drug used for treatment of canine atopic dermatitis, on the cutaneous release of two pro-inflammatory mediators following intradermal allergen challenge. Four beagle dogs spontaneously sensitized to Ascaris suum were treated for 1 month with oral cyclosporin A. At days 0, 15 and 30 of the treatment, dialysis probes were inserted into the skin of the back, and 20 microL of A. suum antigen was injected intradermally at each site. At timed intervals, dialysate was collected and assayed for histamine and prostaglandin D(2) and the wheal area was measured. Mean histamine concentration and wheal area were significantly lower at days 15 and 30 of treatment, compared with day 0. However, prostaglandin D(2) concentration was not significantly reduced. The inhibition in histamine release after intradermal challenge, by cyclosporin, confirms its anti-inflammatory action in the dog. Dermal microdialysis provides a useful tool for investigating canine allergic reactions and their modulation by drugs.     

The mtDNA legacy of the Levantine early Upper Palaeolithic in Africa

Sequencing of 81 entire human mitochondrial DNAs (mtDNAs) belonging to haplogroups M1 and U6 reveals that these predominantly North African clades arose in southwestern Asia and moved together to Africa about 40,000 to 45,000 years ago. Their arrival temporally overlaps with the event(s) that led to the peopling of Europe by modern humans and was most likely the result of the same change in climate conditions that allowed humans to enter the Levant, opening the way to the colonization of both Europe and North Africa. Thus, the early Upper Palaeolithic population(s) carrying M1 and U6 did not return to Africa along the southern coastal route of the "out of Africa" exit, but from the Mediterranean area; and the North African Dabban and European Aurignacian industries derived from a common Levantine source.     

Organics captured from comet 81P/Wild 2 by the Stardust spacecraft

Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples.     

Nanoparticle polymer composites: where two small worlds meet

The mixing of polymers and nanoparticles is opening pathways for engineering flexible composites that exhibit advantageous electrical, optical, or mechanical properties. Recent advances reveal routes to exploit both enthalpic and entropic interactions so as to direct the spatial distribution of nanoparticles and thereby control the macroscopic performance of the material. For example, by tailoring the particle coating and size, researchers have created self-healing materials for improved sustainability and self-corralling rods for photovoltaic applications. A challenge for future studies is to create hierarchically structured composites in which each sublayer contributes a distinct function to yield a mechanically integrated, multifunctional material.     

Human hair growth deficiency is linked to a genetic defect in the phospholipase gene LIPH

The molecular mechanisms controlling human hair growth and scalp hair loss are poorly understood. By screening about 350,000 individuals in two populations from the Volga-Ural region of Russia, we identified a gene mutation in families who show an inherited form of hair loss and a hair growth defect. Affected individuals were homozygous for a deletion in the LIPH gene on chromosome 3q27, caused by short interspersed nuclear element-retrotransposon-mediated recombination. The LIPH gene is expressed in hair follicles and encodes a phospholipase called lipase H (alternatively known as membrane-associated phosphatidic acid-selective phospholipase A1alpha), an enzyme that regulates the production of bioactive lipids. These results suggest that lipase H participates in hair growth and development.     

Antimicrobial susceptibility patterns of respiratory tract pathogens from sheep and goats

OBJECTIVE: To determine the antimicrobial susceptibility of common respiratory tract pathogens from sheep and goats. DESIGN: Cross-sectional study. SAMPLE POPULATION: 41 respiratory tract isolates from sheep and 36 isolates from goats. PROCEDURES: Disk diffusion assay was used to determine antimicrobial susceptibility of isolates to amoxicillin-clavulanic acid, ceftiofur, ciprofloxacin, florfenicol, and tetracycline. Minimum inhibitory concentrations of florfenicol for these isolates were determined by use of the microbroth dilution technique. RESULTS: The most common isolates were Pasteurella multocida (n = 28) and Mannheimia haemolytica (39). All isolates were susceptible to amoxicillin-clavulanic acid, ceftiofur, ciprofloxacin, and florfenicol. Five percent (4/77) of isolates were resistant to tetracycline. CONCLUSIONS AND CLINICAL RELEVANCE: Susceptibility of respiratory tract pathogens isolated from sheep and goats to commonly used antimicrobial drugs in this study was high. Treatment of these species for bacterial respiratory tract disease is likely not complicated by antimicrobial resistance.     

Genetic variation in Puccinia graminis collected from oats, rye, and barberry

Puccinia graminis, the causal agent of stem rust, was collected from its alternate host barberry (Berberis spp.) and two different uredinial hosts, oats (Avena sativa) and rye (Secale cereale). The samples were analyzed using 11 polymorphic simple sequence repeat (SSR) markers. There were large differences between fungal populations on oats (P. graminis f. sp. avenae) and rye (P. graminis f. sp. secalis), and the genetic variation within the different formae speciales was also high. It was possible to distinguish between the two formae speciales on barberry. Additional genotypic groups not present in the field samples from oats and rye were also identified on barberry. Our results confirm the importance of barberry in maintaining the populations of P. graminis in Sweden and the importance of the sexual stage for the survival of the pathogen.     

Molecular characterization of Fusarium oxysporum f.sp. cichorii pathogenic on chicory (Cichorium intybus)

Fusarium oxysporum is a ubiquitous soilborne ascomycete responsible for vascular wilt in many plant species worldwide. This species comprises more than 120 putative host-specific formae speciales capable of causing marked economic losses. In summer 2009, wilt symptoms, including chlorosis and poor development of the root system, were observed on cultivars of chicory (Cichorium intybus) in northern Italy. The causal agent isolated from symptomatic tissues in this case was identified as F. oxysporum on the basis of both morphological features and molecular analyses. In this work, we attempted to characterize the isolates of F. oxysporum from C. intybus by both biological and molecular approaches. Pathogenicity trials performed on five species of the Asteraceae family with isolates of F. oxysporum from C. intybus indicated that the pathogen has a unique host range, infecting chicory only. Neither lettuce nor endive, lawn daisy or Paris daisy developed the disease. Five cultivars within C. intybus species were tested, and the cv. ??Clio?? was the most susceptible. Phylogenetic analyses relative to the ribosomal intergenic spacer (IGS) and translation elongation factor 1-alpha (EF1-??) assigned isolates pathogenic to chicory to a single cluster, distinct from other pathogenic F. oxysporum. In light of these findings, we propose to designate this organism as Fusarium oxysporum f.sp. cichorii.     

Carbon isotope constraints on the deglacial CO₂ rise from ice cores

The stable carbon isotope ratio of atmospheric CO(2) (δ(13)C(atm)) is a key parameter in deciphering past carbon cycle changes. Here we present δ(13)C(atm) data for the past 24,000 years derived from three independent records from two Antarctic ice cores. We conclude that a pronounced 0.3 per mil decrease in δ(13)C(atm) during the early deglaciation can be best explained by upwelling of old, carbon-enriched waters in the Southern Ocean. Later in the deglaciation, regrowth of the terrestrial biosphere, changes in sea surface temperature, and ocean circulation governed the δ(13)C(atm) evolution. During the Last Glacial Maximum, δ(13)C(atm) and atmospheric CO(2) concentration were essentially constant, which suggests that the carbon cycle was in dynamic equilibrium and that the net transfer of carbon to the deep ocean had occurred before then.