The Role of Helicobacter pylori in Children with Recurrent Abdominal Pain

Objectives: Our major goals in this study were to determine the prevalence of Helicobacter pylori among Israeli children with recurrent abdominal pain and to establish whether a link exists between eradication of Helicobacter pylori and the recovery from abdominal pain. The alternative target was to examine whether the serological test can replace endoscopy in children. Methods: Upper gastrointestinal endoscopy was performed in 80 children with recurrent abdominal pain. During endoscopy, antral biopsies were taken and sent for histo-logical and bacteriological examination. Results: The prevalence of H. pylori , which was indicated by Gram stain and urease test, was 54%. The positive cases were treated with bismuth combined with amoxycillin and metronidazole. Two months after completion of the treatment, 34 patients were reexamined. Twenty-nine of them (85%) became symptom free, and five (15%) remained symptomatic. These five children were retreated, and they also became symptom free. Eight months after completion of treatment, all 34 patients were reexamined and found to be asymptomatic. Conclusions: We found a high prevalence of H. pylori (54%) among Israeli children with recurrent abdominal pain; we also found that symptoms were effectively and significantly reduced by the eradication of H. pylori . The endoscopic examination cannot be replaced by serological test.     

Presynaptic architecture of the larval zebrafish neuromuscular junction

This article shows the ultrastructural architecture of larval zebrafish (Danio rerio) neuromuscular junctions in three dimensions. We compare classical electron microscopy fixation techniques with high‐pressure freezing followed by freeze substitution (HPF/FS) in combination with electron tomography. Furthermore, we compare the structure of neuromuscular junctions in 4‐ and 8‐dpf zebrafish larvae with HPF/FS because this allows for close‐to‐native ultrastructural preservation. We discovered that synaptic vesicles of 4‐dpf zebrafish larvae are larger than those of 8‐dpf larvae. Furthermore, we describe two types of dense‐core vesicles and quantify a filamentous network of small filaments interconnecting synaptic vesicles as well as tethers connecting synaptic vesicles to the presynaptic cell membrane. In the center of active zones, we found elaborate electron‐dense projections physically connecting vesicles of the synaptic vesicle pool to the presynaptic membrane. Overall this study establishes the basis for systematic comparisons of synaptic architecture at high resolution in three dimensions of an intact vertebrate in a close‐to‐native state. Furthermore, we provide quantitative information that builds the basis for diverse systems biology approaches in neuroscience, from comparative anatomy to cellular simulations. J. Comp. Neurol. 523:1984–1997, 2015 © 2015 Wiley Periodicals, Inc.     

Recurrence of Melanoma Following T Cell Treatment: Continued Antigen Expression in a Tumor That Evades T Cell Recruitment

Clinical therapy with T cells shows promise for cancer patients, but is currently challenged by incomplete responses and tumor relapse. The exact mechanisms that contribute to tumor relapse remain largely unclear. Here, we treated mouse melanomas with T cell receptor-engineered T cells directed against a human peptide-major histocompatibility complex antigen in immune-competent mice. T cells resulted in significant tumor regression, which was followed by relapse in about 80–90% of mice. Molecular analysis revealed that relapsed tumors harbored nonmutated antigen genes, not silenced by promoter methylation, and functionally expressed surface antigen at levels equal to nontreated tumors. Relapsed tumors resisted a second in vivo T cell treatment, but regained sensitivity to T cell treatment upon retransplantation in mice. Notably, relapsed tumors demonstrated decreased levels of CD8 T cells and monocytes, which were substantiated by downregulated expression of chemoattractants and adhesion molecules. These observations were confirmed when using T cells specific for a less immunogenic, endogenous mouse melanoma antigen. We conclude that tumors, when exposed to T cell treatment, can relapse without loss of antigen and develop a milieu that evades recruitment of effector CD8 T cells. Our findings support the concept to target the tumor milieu to aid T cell therapy in limiting tumor relapse