Characteristics of lipo-oligosaccharide loci of Campylobacter jejuni isolates associated with Guillain-Barré Syndrome from Hebei, China.

Ganglioside mimicry by C.jejuni lipo-oligosaccharides (LOS) could induce the production of autoantibodies against gangliosides and the development of Guillain-Barré syndrome (GBS). The LOS biosynthesis region exhibits significant variation with different strains. Using PCR amplifications of genes from published LOS loci and sequencing the LOS biosynthesis loci, the eight GBS-associated C. jejuni strains from HeBei could be classified into four classes. The expression of sialylated LOS structures (class A) or non-sialylated LOS structures(class F, H and P) in the C. jejuni LOS is considered to be two different factors for the induction of GBS.

Endoplasmic reticulum in the penumbra following middle cerebral artery occlusion in the rabbit.

Caspase-12 has been localized to endoplasmic reticulum (ER) and showed to involve ER stress-induced apoptosis. In the present work we investigated the temporospatial alterations of caspase-12 immunoreactivity in the penumbra following cerebral ischemia/reperfusion in rabbit. Transient cerebral ischemia was produced by intraluminal occlusion of the middle cerebral artery for 2 h followed by 1 h, 6 h, 1 day, 3 days, 7 days and 14 days of reperfusion. Caspase-12 immunohistochemistry was first increased in the penumbra 1 h after reperfusion, with a peak at day 1 to day 3, and then gradually decreased to basal level at day 14. The number of TUNEL-positive cells and ultrastructural observation of brain sections in the penumbra showed a similar change at the same time points. ER mediated by caspase-12 participated in apoptosis induced by cerebral ischemia/reperfusion injury, which may provide a new area for therapeutic intervention to ameliorate outcomes following cerebral ischemia.

A modified rabbit model of stroke: evaluation using clinical MRI scanner.

OBJECTIVE: Occluding the middle cerebral artery of small animals with an intraluminal filament to build a stroke model has gained increasing acceptance. In light of the growing demand for magnetic resonance imaging (MRI) studies using the clinical MRI scanner, large animal models can be superior to small animal models. In this work, we developed a modified rabbit model of stroke, which was assessed using clinical MRI scanner and compared with a most commonly silicone-coated filament model. METHODS: We presented a focal cerebral ischemia in rabbits. The key feature of this modified method is the use of a guide wire as a 'nylon suture'. At 3 days after ischemia, the percentage of brain infarct volume, neurobehavioral score, intracranial hemorrhagic incidence and dynamic changes of T(2) and apparent diffusion coefficient values were assessed respectively and compared between the focal cerebral models. RESULTS: Wire-induced models had more severe brain infarct size with less dispersion (32.7 +/- 6.5%, coefficient of variation=0.20) than that with filament models (25.4 +/- 8.9%, coefficient of variation=0.31; p<0.05). There were more significant MRI changes in the early stage, higher rate of technique success (wire, 20/20; filament, 17/20) and less intracranial hemorrhage (wire, 0/20; filament, 3/20) in wire-induced models than in filament-induced rabbits (p<0.05). CONCLUSION: Our data suggest that wire-induced method can provide a useful tool for the earlier research of ischemia.

[Preliminary analysis on the proteomic feature of Guillain-Barré syndrome-associated Campylobacter jejuni].

OBJECTIVE: To search the marker proteins of Guillain-Barré syndrome (GBS)-associated Campylobacter jejuni (C. jejuni) by comparing the protein maps of GBS-associated C. jejuni strains with that of non-GBS-associated C. jejuni strains. METHODS: The whole-cell proteins of eight GBS-associated and eight non-GBS-associated C. jejuni strains were separated using the two-dimensional gel electrophoresis respectively. The differentially expressed proteins between the two sets of strains were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) after in-gel tryptic digestion. RESULTS: Twenty differentially expressed spots were found with seventeen identified ones using MSCOT database. These proteins were identified as wlaX protein and some other proteins involving in energy metabolism (malate dehydrogenase, triosephosphate isomerase, Ni/Fe-hydrogenase small chain, cysteine synthase, branched-chain amino acid aminotransferase), cell process (heat shock protein, iron-uptake ABC transport system periplasmic iron-binding protein, alkyl hydroperoxide reductase), cell envelope (flagellin, UDP-N-acetylenolpyruvoylglucosamine reductase) etc. CONCLUSION: WlaX proteins were probably associated with LPS biosynthesis or virulence of C. jejuni. WlaX protein and flagellin protein were the possible marker-proteins of GBS-associated C. jejuni strains.