Differential magnetic field effects on heart rate and nociception in anosmic pigeons

Several studies have shown that exposure to altered magnetic fields affects nociception by suppressing stress‐induced hypoalgesia, and that this effect is reduced or abolished if the treatment is performed in the absence of light. This raises the question as to whether other sources of sensory stimuli may also modulate these magnetic effects. We investigated the possible role of olfaction in the magnetically induced effects on sensitivity to nociceptive stimuli and heart rate (HR) in restraint‐stressed homing pigeons exposed to an Earth‐strength, irregularly varying (<1 Hz) magnetic field. The magnetic treatment decreased the nociceptive threshold in normally smelling birds and an opposite effect was observed in birds made anosmic by nostril plugging. Conversely, no differential effect of olfactory deprivation was observed on HR, which was reduced by the magnetic treatment both in smelling and anosmic pigeons. The findings highlight an important role of olfactory environmental information in the mediation of magnetic effects on nociception, although the data cannot be interpreted unambiguously because of the lack of an additional control group of olfactory‐deprived, non‐magnetically exposed pigeons. The differential effects on a pigeon's sensitivity to nociceptive stimulus and HR additionally indicate that the magnetic stimuli affect nociception and the cardiovascular system in different ways. Bioelectromagnetics 33:309–319, 2012. © 2011 Wiley Periodicals, Inc.     

CD80+Gr-1+ myeloid cells inhibit development of antifungal Th1 immunity in mice with candidiasis

To find out whether polymorphonuclear neutrophils (PMN), abundantly recruited in disseminated Candida albicans infection, could directly affect the activation of Th cells we addressed the issues as to whether murine PMN, like their human counterparts, express costimulatory molecules and the functional consequence of this expression in terms of antifungal immune resistance. To this purpose, we assessed 1) the expression of CD80 (B7-1) and CD86 (B7-2) molecules on peripheral, splenic, and inflammatory murine Gr-1+ PMN; 2) its modulation upon interaction with C. albicans in vitro, in vivo, and in human PMN; 3) the effect of Candida exposure on the ability of murine PMN to affect CD4+ Th1 cell proliferation and cytokine production; and 4) the mechanism responsible for this effect. Murine PMN constitutively expressed CD80 molecules on both the surface and intracellularly; however, in both murine and human PMN, CD80 expression was differentially modulated upon interaction with Candida yeasts or hyphae in vitro as well as in infected mice. The expression of the CD86 molecule was neither constitutive nor inducible upon exposure to the fungus. In vitro, Gr-1+ PMN were found to inhibit the activation of IFN-gamma-producing CD4+ T cells and to induce apoptosis through a CD80/CD28-dependent mechanism. A population of CD80+Gr-1+ myeloid cells was found to be expanded in conventional as well as in bone marrow-transplanted mice with disseminated candidiasis, but its depletion increased the IFN-gamma-mediated antifungal resistance. These data indicate that alternatively activated PMN expressing CD80 may adversely affect Th1-dependent resistance in fungal infections.     

T cell vaccination in mice with invasive pulmonary aspergillosis

Aspergillus fumigatus, an opportunistic fungal pathogen, is responsible for multiple airway diseases of an allergic and a nonallergic nature. In a murine model of invasive pulmonary aspergillosis, resistance is associated with a decreased lung inflammatory pathology and the occurrence of an IL-12-dependent Th1-type reactivity that are both impaired by IL-4. In the present study we assess the ability of Aspergillus crude culture filtrate Ags and the recombinant allergen Asp f 2 to induce protective antifungal responses in mice with invasive pulmonary aspergillosis. Similar to what occurred upon nasal exposure to viable A. fumigatus conidia, treatment of immunocompetent mice with Aspergillus crude culture filtrate Ags resulted in the development of local and peripheral protective Th1 memory responses, mediated by Ag-specific CD4+ T cells producing IFN-gamma and IL-2 capable of conferring protection upon adoptive transfer to naive recipients. Protective Th1 responses could not be observed in mice deficient of IFN-gamma or IL-12 and did not occur in response to Asp f 2, which, on the contrary, elicited high level production of inhibitory IL-4. The results show that Ags of Aspergillus exist with the ability to induce both Th1- and Th2-type reactivity during infection, a finding that suggests a possible mechanism through which potentially protective immune responses are inhibited in mice with the infection. However, the occurrence of Th1-mediated resistance upon vaccination with Aspergillus crude culture filtrate Ags, suggests the existence of fungal Ags useful as a candidate vaccine against invasive pulmonary aspergillosis.     

Sequence plasticity in the antigen-binding site of a therapeutic anti-HER2 antibody

We have examined the plasticity of the antigen-combining site of a high-affinity antibody. In phage-displayed Fab libraries, selected CDR positions and one FR position of the humanized anti-Her2 antibody hu4D5 were substituted with all 20 amino acids. Antigen-binding selections were used to enrich for high-affinity variants, and a large number of sequences were obtained prior to convergence of the selected pool to a small set of clones. As expected, sequence variability of the antigen-binding site is overall diminished compared to known IgG sequences; however, certain positions retain much higher variability than others. The sequence variability map of the hu4D5 binding site is compared with a map derived from previous alanine-scanning of the antibody. Affinities of soluble Fab fragments for antigen confirm that multiple variants were selected with high affinity for antigen, including one variant with a single point mutation that was about threefold improved in affinity compared to the parental hu4D5. Interestingly, this mutation is one of the most radical in terms of changing side-chain chemistry (Trp for Asp) and occurs at the most plastic site as calculated by the Wu-Kabat variability coefficient. Thus variability mapping yields information about the antibody-antigen interaction that is useful and complementary to that obtained by alanine scanning mutagenesis.     

Hepatic and pancreatic glycosphingolipid phenotypes of the neurological different rat strains

Among three commonly used strains of laboratory rats, Wistar rats perform more neurological tasks better then Lewis and Sprague-Dawley (SD) rats. Liver is the main site of insulin-like growth factor (IGF) production and pancreas is the exclusive site of insulin production. Insulin stimulates neuronal development and appropriate IGF-I input is critical in brain growth. Glycosphingolipids (GSLs) are important mediators of insulin secretion and action. Therefore, this study investigated GSL phenotypes of liver and pancreas with hypothesis that they are different in three rat strains. Total GSL fractions (neutral and gangliosides) were analysed by high performance thin-layer chromatography (HPTLC). Complex gangliosides were detected by HPTLC immunostaining using cholera toxin B subunit after neuraminidase pretreatment. Wistar rats had the highest liver weight/body weight ratio and SD rats had the highest pancreas weight/body weight ratio. Ganglioside GM3 was more expressed in the liver of Wistar compared to Lewis and SD rats. SD rats contained scarce quantities of GD1a and b-series gangliosides in the liver compared to Wistar and Lewis rats. Pancreatic b-series ganglioside content was also the lowest in SD rats. This study represents differences in the hepatic and pancreatic ganglioside phenotypes of three rat strains that could influence IGF and insulin secretion and action.     

A Missense Mutation in KCTD17 Causes Autosomal Dominant Myoclonus-Dystonia

Myoclonus-dystonia (M-D) is a rare movement disorder characterized by a combination of non-epileptic myoclonic jerks and dystonia. SGCE mutations represent a major cause for familial M-D being responsible for 30%–50% of cases. After excluding SGCE mutations, we identified through a combination of linkage analysis and whole-exome sequencing KCTD17 c.434 G>A p.(Arg145His) as the only segregating variant in a dominant British pedigree with seven subjects affected by M-D. A subsequent screening in a cohort of M-D cases without mutations in SGCE revealed the same KCTD17 variant in a German family. The clinical presentation of the KCTD17-mutated cases was distinct from the phenotype usually observed in M-D due to SGCE mutations. All cases initially presented with mild myoclonus affecting the upper limbs. Dystonia showed a progressive course, with increasing severity of symptoms and spreading from the cranio-cervical region to other sites. KCTD17 is abundantly expressed in all brain regions with the highest expression in the putamen. Weighted gene co-expression network analysis, based on mRNA expression profile of brain samples from neuropathologically healthy individuals, showed that KCTD17 is part of a putamen gene network, which is significantly enriched for dystonia genes. Functional annotation of the network showed an over-representation of genes involved in post-synaptic dopaminergic transmission. Functional studies in mutation bearing fibroblasts demonstrated abnormalities in endoplasmic reticulum-dependent calcium signaling. In conclusion, we demonstrate that the KCTD17 c.434 G>A p.(Arg145His) mutation causes autosomal dominant M-D. Further functional studies are warranted to further characterize the nature of KCTD17 contribution to the molecular pathogenesis of M-D.     

Neurodevelopmental outcome in children with periventricular leukomalacia

The purpose of this study was to question the correlation of different grades of periventricular leukomalacia (PVL) and subsequent neurodevelopmental outcome. In a prospective study we followed 52 preterm infants. Infants were divided into three groups according to their cranial ultrasound findings of PVL (De Vries classification). Seventeen children had PVL 1, 20 children had PVL 2, and 15 children had PVL 3. All 15 (100%) children with PVL 3 developed cerebral palsy with additional visual perceptual dysfunctions and epilepsy. Children with PVL 1 had high frequency of mild neuromotoric delay and visual impairment. PVL 2 and 3 have great predictive value for subsequent severe neurodevelopmental disorder which refers to cerebral palsy, different cognitive deficits, vision impairment and epilepsy. We have determined that due to high frequency of visual impairment and epilepsy we need to include neurophysiologic examinations very early in children with PVL lesions.