Postoperative MR Imaging of Spontaneous Transdural Spinal Cord Herniation: Expected Findings and Complications.

BACKGROUND AND PURPOSE: Spontaneous transdural spinal cord herniation is no longer a rare cause of myelopathy. The high frequency of diagnoses has led to an increase in the number of surgical procedures. The purpose of this study was to describe the spectrum of postoperative MR imaging findings concerning spontaneous transdural spinal cord herniation and to provide a practical imaging approach for differentiating expected changes and complications after an operation. MATERIALS AND METHODS: We retrospectively reviewed MR images from 12 patients surgically treated for spontaneous transdural spinal cord herniation. Surgery comprised either dural defect enlargement or duraplasty procedures. Postoperative follow-ups included at least 3 (early, intermediate, late) MR imaging studies. MR images were analyzed with respect to 3 spinal compartments: intradural intramedullary, intradural extramedullary, and extradural. The meaning and reliability of changes detected on MR images were related to their radiologic and clinical evolution with time. RESULTS: Spinal cord realignment has been stable since the early study, whereas spinal cord signal and thickness evolved during the following scans. Most extramedullary and extradural changes gradually reduced in later MR images. Three patients treated with dural defect enlargements experienced the onset of new neurologic symptoms. In those patients, late MR images showed extradural fluid collection and the development of pial siderosis. CONCLUSIONS: Our findings demonstrate the spectrum of postoperative imaging findings in spontaneous transdural spinal cord herniation. Spinal cord thickness and signal intensity continued to evolve with time; most extramedullary postsurgical changes became stable. Changes observed in later images may be suggestive of complications.

Effect of coronary percutaneous revascularization on interferon-gamma and interleukin-10 producing CD4+ T cells during acute myocardial infarction.

T lymphocytes play an important role in the induction and progression of acute coronary syndromes (ACS). To gain insight into how different T cell subsets can influence ACS, we analyzed the frequencies of circulating CD4+ T cells producing either pro-inflammatory interferon(IFN)-gamma or anti-inflammatory interleukin (IL)-10 in subjects presenting with ST-elevation myocardial infarction (STEMI). The effect of coronary bare metal (BS) and paclitaxel-eluting stent (PES) on the balance between CD4+IFN-gamma+ and CD4+IL-10+ lymphocytes was also investigated. Peripheral blood mononuclear cells (PBMC) were isolated from 38 consecutive patients with STEMI before and 48 hrs or 6 days after implantation of either BS or PES. Twenty patients with no history of coronary artery disease were included as basal controls. PBMC were stimulated in vitro with anti-CD3/anti-CD28 monoclonal antibodies, and CD4+IFN- gamma+ or CD4+IL-10+ T cells were detected by flow cytometry intracellular staining. The frequency of peripheral CD4+IL-10+ T cells was significantly higher in STEMI patients as compared with controls. Conversely, the frequency of CD4+IFN-gamma+ T lymphocytes did not differ between STEMI and subjects without history of coronary artery disease. Six days after the revascularization procedure, the percentage of CD4+IL-10+ T cells was significantly decreased in BS but not in the PES group, whereas the relative percentage of CD4+IFN-gamma+ T lymphocytes were diminished in both groups as compared with baseline levels. Our data indicate that STEMI is associated with a peripheral expansion of CD4+IL-10+ T lymphocytes, and that primary coronary revascularization with implantation of either BS or PES is followed by a reduction in circulating CD4+IFN-gamma+ T lymphocytes. PES implantation, however, appears to inhibit the relative decrease of the IL-10 producing lymphocyte as observed in BS implanted patients, shifting the balance between pro-inflammatory and anti-inflammatory T cell populations in favor of the latter.

Effects of xylitol, sorbitol and fluoride mouthrinses on glucose clearance in adolescents.

The present work describes and analyzes the results of a randomized clinical trial on 98 healthy adolescents (age 18 +/- 0.7 years) in order to evaluate the effects of a 14 days treatment with mouthrinses containing xylitol (0.2%; 0.5% and 1%), sorbitol (1%), NaF (0.1% respectively) on salivary glucose clearance. In all volunteers oral glucose clearance followed an exponential curve as a function of time, which fitted almost exactly to the equation log Ct = log Co - bt from 1 to 16 minutes after sugar rinsing. Xylitol treatment provoked an increase in oral glucose clearance, which was proportional to its concentration in the mouthrinse formula. The average AUC (area under curve) decrease was 9.1% in subjects rinsing with 0.2% xylitol; 21.5% with 0.5% xylitol and 40.0% with 1% xylitol. 1% sorbitol or 0.1% NaF did not modify any of the pharmacokinetical parameters over the same treatment time. The mouthrinses containing 1% xylitol and 0.1% NaF produced the same results as 1% xylitol alone on oral glucose clearance. No significant changes in the salivary flow rate nor in oral health parameters were observed concomitant to the faster oral glucose clearance by xylitol treatment. Since the sugars salivary clearance is part of a process intended to prevent dental caries, our results suggest that xylitol adds another mechanism of action to its well known cariostatic and anticaries properties.