Identification of brown adipose tissue using MR imaging in a human adult with histological and immunohistochemical confirmation

OBJECTIVE

Manipulation of human brown adipose tissue (BAT) represents a novel therapeutic option for diabesity. The aim of our study was to develop and test a novel magnetic resonance (MR) imaging-based method to identify human BAT, delineate it from white adipose tissue, and validate it through immunohistochemistry.

DESIGN

A 25-year old Caucasian female with hyperparathyroidism-jaw tumor syndrome underwent parathyroidectomy. An (18)fluoro-2-deoxyglucose positron emission tomography (PET)-computed tomography (CT) scan performed after surgery ruled out malignancy but showed avid uptake within the mediastinum, neck, supraclavicular fossae, and axillae, consistent with BAT. Immunohistochemical staining using uncoupling protein-1 antibody was performed on one fat sample obtained from the suprasternal area during parathyroidectomy. Subsequently, serial MR scans were performed. Retrospectively, regions of interest (ROIs) were identified on MR corresponding to areas of high uptake on PET-CT. Prospectively, ROIs were identified on MR based on signal intensity and appearance and compared with PET-CT.

RESULTS

Of 111 retrospectively identified ROIs from PET-CT, 93 (83.8%) showed corresponding low MR signal: 25 of 25 mediastinum (100%), 29 of 31 neck (93.5%), 31 of 41 supraclavicular (75.6%), and 8 of 14 axillae (57%). Prospectively, 47 of 54 ROIs identified on MR (87%) showed a corresponding increased uptake on PET-CT. Serendipitously, the sample obtained at surgery corresponded with high uptake and low signal on subsequent PET and MR, respectively, and immunohistochemistry confirmed BAT.

CONCLUSION

We provide the first report for the reliable use of MR to identify BAT in a living human adult, with histological/immunohistochemical confirmation. Our data demonstrate proof of concept to support the development of MR as a safe, reproducible imaging modality for human BAT.

Breaking the speed limits of phase-change memory

Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystallization (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystallization kinetics of a phase-change material by applying a constant low voltage via prestructural ordering (incubation) effects. A crystallization speed of 500 picoseconds was achieved, as well as high-speed reversible switching using 500-picosecond pulses. Ab initio molecular dynamics simulations reveal the phase-change kinetics in PCRAM devices and the structural origin of the incubation-assisted increase in crystallization speed. This paves the way for achieving a broadly applicable memory device, capable of nonvolatile operations beyond gigahertz data-transfer rates.

A Case of Ovarian Fibromatosis and Massive Ovarian Oedema Associated With Intra-Abdominal Fibromatosis, Sclerosing Peritonitis and Meig's Syndrome

Purpose:To discuss a case of ovarian fibromatosis/massive ovarian oedema, intra-abdominal fibromatosis, sclerosing peritonitis and Meig's syndrome. To review the reported therapeutic options.

Patients: Case report of a 27-year-old female with the combined pathology of ovarian fibromatosis/massive ovarian oedema, intra-abdominal fibromatosis, sclerosing peritonitis and Meig's syndrome.

Methods: This patient was treated with supportive care and cytotoxic chemotherapy.

Results: Despite the benign nature of the ovarian pathology, this patient presented with life-threatening complications. Response to treatment was probably multi-factorial combining the effects of cytotoxics, use of steroids and good supportive care. She remains in complete remission 4 years post completion of chemotherapy.

Conclusion: There are reports in the literature of ovarian fibromatosis/massive ovarian oedema, luteinised thecomas, intraabdominal fibromatosis and Meig's syndrome occurring together in a variety of combinations. Treatment has been described with radiotherapy, cytotoxic and non-cytotoxic chemotherapy regimens. This case provides a link between ovarian fibromatosis/massive ovarian oedema, intra-abdominal fibromatosis, sclerosing peritonitis and Meig's syndrome not previously described.

A rationale for membrane peeling in the repair of stage 4 macular holes

AIM

To examine the histological and immunocytochemical characteristics of epiretinal membranes (ERM) associated with stage 4 macular holes (MH) so as to establish a vitreoretinal rationale for surgery in stage 4 MH.

METHOD

Consecutive patients with stage 4 MH undergoing vitrectomy and membrane peeling were recruited. Preoperatively, the eyes were examined for ERM formation over the macula and completeness of posterior hyaloid membrane (PHM) separation from the retina. ERM peel specimens obtained during surgery were sent for histological and immunocytochemical studies and were compared with the PHM specimens taken from a previous post-mortem study of eyes with physiological posterior vitreous detachment but without macular holes.

RESULT

A total of 13 patients with stage 4 MH fulfilled the inclusion criteria and were recruited. Preoperatively, all eyes had an ERM over the macula and incomplete separation of the PHM seen as a defect in the PHM on specular biomicroscopy. Histologically, the ERM specimens had very similar morphological characteristics to PHM, consisting of an eosinophilic membrane of varying thickness with scattered spindle-shaped cells. The membranes stained positively for type IV collagen while the cells were glial fibrillary acidic protein positive. Postoperatively, successful closure of MH was achieved in all cases.

CONCLUSION

Stage 4 MH is characterised by incomplete separation of the PHM from the retina with remnants overlying the macula manifesting as ERM. Removal of the ERM is required during vitrectomy in order to relieve the tangential forces involved in the development of MH.