Diagnostic accuracy of high-resolution MRI using a microscopy coil for patients with presumed DCIS following mammography screening

PURPOSE: To prospectively evaluate the accuracy of high-resolution (HR)-MRI as a secondary examination in women with abnormal calcifications detected on mammography. MATERIALS AND METHODS: We used a 4.7-cm microscopy coil to acquire HR-MRI signal data. We examined 52 women with breast lesions preoperatively using HR-MRI and vacuum-assisted core needle biopsy. The lesions were suspicious of malignancy, classified as category 3-5 on mammography (Breast Imaging Reporting and Data System [BI-RADS]), and without a palpable mass. All visualized suspicious lesions were correlated with histological findings. We compared the HR-MRI and pathological findings and calculated the sensitivity, specificity, and accuracy. RESULTS: We compared the breast HR-MRI results with the gold standard of pathological results for studies of malignancy (DCIS and invasive cancer), and found a sensitivity of 88.5%, specificity of 92.3%, and accuracy of 90.4%. The positive predictive value (PPV) was 92%, and the negative predictive value (NPV) was 88.9%. When breast MRI was compared with pathological results for studies that diagnosed DCIS only, the results revealed a sensitivity of 88.6%, specificity of 88.2%, accuracy of 88.5%, PPV of 93.9%, and NPV of 78.9%. CONCLUSION: HR-MRI using a microscopy coil is a useful, reliable, safe, and minimally invasive procedure that is a good choice for secondary assessment of abnormal calcification in the breast.     

Partial volume effect-corrected FDG PET and grey matter volume loss in patients with mild Alzheimer’s disease

Purpose Although ¹⁸F-fluorodeoxyglucose (FDG) PET is an established imaging technique to assess brain glucose utilisation, accurate measurement of tracer concentration is confounded by the presence of partial volume effect (PVE) due to the limited spatial resolution of PET, which is particularly true in atrophic brains such as those encountered in patients with Alzheimer’s disease (AD). Our aim was to investigate the effects of PVE correction on FDG PET in conjunction with voxel-based morphometry (VBM) in patients with mild AD. Methods Thirty-nine AD patients and 73 controls underwent FDG PET and MRI. The PVE-corrected grey matter PET images were obtained using an MRI-based three-compartment method. Additionally, the results of PET were compared with grey matter loss detected by VBM. Results Before PVE correction, reduced FDG uptake was observed in posterior cingulate gyri (PCG) and parieto-temporal lobes (PTL) in AD patients, which persisted after PVE correction. Notably, PVE correction revealed relatively preserved FDG uptake in hippocampal areas, despite the grey matter loss in medial temporal lobe (MTL) revealed by VBM. Conclusion FDG uptake in PCG and PTL is reduced in AD regardless of whether or not PVE correction is applied, supporting the notion that the reduced FDG uptake in these areas is not the result of atrophy. Furthermore, FDG uptake by grey matter tissue in the MTL, including hippocampal areas, is relatively preserved, suggesting that compensatory mechanisms may play a role in patients with mild AD. Disclosure: The authors have reported no conflicts of interest.     

A multicenter study on oncologic outcome of laparoscopic gastrectomy for early cancer in Japan

BACKGROUND: Laparoscopic surgery for gastric cancer is technically feasible, but it is not widely accepted because it has not been evaluated from the standpoint of oncologic outcome. We conducted a retrospective, multicenter study of a large series of patients in Japan to evaluate the short- and long-term outcomes of laparoscopic gastrectomy for early gastric cancer (EGC). METHODS: The study group comprised 1294 patients who underwent laparoscopic gastrectomy during the period April 1994 through December 2003 in 16 participating surgical units (Japanese Laparoscopic Surgery Study Group). The short- and long-term outcomes of these patients were examined. RESULTS: Distal gastrectomy was performed in 1185 patients (91.5%), proximal gastrectomy in 54 (4.2%), and total gastrectomy in 55 (4.3%); all were performed laparoscopically. The morbidity and mortality rates associated with these operations were 14.8% and 0%, respectively. Histologically, 1212 patients (93.7%) had stage IA disease, 75 (5.8%) had stage IB disease, and 7 (0.5%) had stage II disease (the UICC staging). Cancer recurred in only 6 (0.6%) of 1294 patients treated curatively (median follow-up, 36 months; range, 13-113 months). The 5-year disease-free survival rate was 99.8% for stage IA disease, 98.7% for stage IB disease, and 85.7% for stage II disease. CONCLUSIONS: Although our findings may be considered preliminary, our data indicate that laparoscopic surgery for EGC yields good short- and long-term oncologic outcomes.     

Ectopic pleural thymoma presenting as a giant mass in the thoracic cavity

We describe a rare case of a giant thymoma that developed in the right thoracic cavity, and seemed to originate from the visceral pleura. We believe that there have been few reports of thymoma developing from such an unusual origin.     

μ-Opioid receptor-independent fashion of the suppression of sodium currents by μ-opioid analgesics in thalamic neurons

Most reports in the literature have shown that the effects of opioid analgesics are primarily mediated by μ-opioid receptor (MOR), whereas other potential targets of opioid analgesics have not been thoroughly characterized. In this study, we found that extracellular application of morphine, fentanyl or oxycodone, which are all considered to be MOR agonists, at relatively high concentrations, but not endogenous μ-opioid peptides, produced a concentration-dependent suppression of sodium currents in cultured thalamic neurons. These effects of opioids were not affected by either a MOR antagonist naloxone or a deletion of MOR gene. Among these opioids, fentanyl strongly suppressed sodium currents to the same degree as lidocaine, and both morphine and oxycodone slightly but significantly reduced sodium currents when they were present extracellularly. In contrast, the intracellular application of morphine, but not oxycodone, fentanyl or lidocaine, reduced sodium currents. These results suggest that morphine, fentanyl and oxycodone each produce the MOR-independent suppression of sodium currents by distinct mechanisms in thalamic neurons.     

Regulation of cellular morphology using temperature-responsive hydrogel for integrin-mediated mechanical force stimulation

A new culture substrate was developed for cells to be equibiaxially stretched using fibronectin (Fn)-immobilized temperature-responsive hydrogel. The cells cultured on the gel substrate were equibiaxially stretched with swelling of the gel, which was accompanied by slight changes of temperature. During gel swelling, changes of cell shape were clearly observed by optical microscopy because of high transparency of the gel. ERK was highly and transiently activated by mechanical stimulation whereas focal adhesion kinase (FAK) was not, indicating that mechanical signals were transduced into biochemical signals in cells. We found that cells formed filopodia-like structures in response to mechanical cues, suggesting that mechanical forces facilitated actin polymerization at the peripheral region. In the cytoplasm, paxillin-containing fibrous structures were formed along actin fibers. These results indicate that we can perform both analysis of intracellular signal transduction and observation of cell shapes at high magnification in our method.