A human strain of Oxalobacter (HC-1) promotes enteric oxalate secretion in the small intestine of mice and reduces urinary oxalate excretion

Enteric oxalate secretion that correlated with reductions in urinary oxalate excretion was previously reported in a mouse model of primary hyperoxaluria, and in wild type (WT) mice colonized with a wild rat strain (OXWR) of Oxalobacter (Am J Physiol 300:G461–G469, 2010). Since a human strain of the bacterium is more likely to be clinically used as a probiotic therapeutic, we tested the effects of HC-1 in WT. Following artificial colonization of WT mice with HC-1, the bacteria were confirmed to be present in the large intestine and, unexpectedly, detected in the small intestine for varying periods of time. The main objective of the present study was to determine whether the presence of HC-1 promoted intestinal secretion in the more proximal segments of the gastrointestinal tract. In addition, we determined whether HC-1 colonization led to reductions in urinary oxalate excretion in these mice. The results show that the human Oxalobacter strain promotes a robust net secretion of oxalate in the distal ileum as well as in the caecum and distal colon and these changes in transport correlate with the beneficial effect of reducing renal excretion of oxalate. We conclude that OXWR effects on intestinal oxalate transport and oxalate homeostasis are not unique to the wild rat strain and that, mechanistically, HC-1 has significant potential for use as a probiotic treatment for hyperoxaluria especially if it is also targeted to the upper and lower gastrointestinal tract.     

Primary multicentric anaplastic pleomorphic xanthoastrocytoma with atypical features

Pleomorphic xanthoastrocytoma (PXA) is a rare tumor with good prognosis after surgery. Few cases of anaplastic PXA (either de novo or secondary to transformation of a recurrent low grade PXA) have been reported. Moreover, primary anaplastic PXA with dissemination at diagnosis has been described only in two patients, to our knowledge. We report the first case of primary multicentric anaplastic PXA and discuss its atypical features and the pertinent literature.     

Effects of repetitive transcranial magnetic stimulation on spike-and-wave discharges

Aim of this study was to evaluate the effect of 5Hz-suprathreshold repetitive transcranial magnetic stimulation (rTMS) on the duration of the spike-and-wave discharges (SWDs) in a patient presenting idiopathic absence seizures. At the moment of the study the patient presented a mild blunting of consciousness due to the high frequency of absences and EEG recordings showed sub-continuous, generalized, symmetrical and synchronous 3c/s SWDs, petit mal status. Trains of 10 stimuli (120% resting motor threshold) were delivered at 5Hz frequency at the beginning of the SWDs. 5Hz-rTMS trains significantly changed the EEG activity by reducing the duration of SWDs without changing the intervals between two consecutive discharges. rTMS had not significant after-effects on the epileptic activity and patient's clinical status. Despite the limitations of a single case report, our neurophysiological findings suggest that 5Hz-suprathreshold rTMS delivered in short trains induces a transitory interference of the ongoing epileptic activity.     

Imaging of pediatric adrenal tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Adrenal tumors other than neuroblastoma are uncommon in children. The most frequently encountered are adrenocortical carcinoma and pheochromocytoma. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary adrenal malignancy other than neuroblastoma at diagnosis and during follow-up.