Gen Kudo

In vivo imaging of microglial activation using a peripheral benzodiazepine receptor ligand: [11C]PK-11195 and animal PET following ethanol injury in rat striatum

ObjectiveTo investigate whether [11C]PK-11195, a specific peripheral benzodiazepine receptors (PBRs) ligand for positron emission tomography (PET), can show activated microglia in a rat brain injury model.MethodsOn day 1, ethanol was injected into the rat’s right striatum (ST) using a stereotaxic operative procedure. On day 3, head magnetic resonance imaging (MRI) scans for surgically treated rats were performed to evaluate ethanol injury morphologically. On day 4, dynamic PET scans (17 injured rats and 7 non-injured controls) were performed for 60 min with an animal PET scanner under chloral hydrate anesthesia following a bolus injection of [11C]PK-11195 through tail vein. Because PBRs are present throughout the brain, there is no suitable receptor-free reference region. The reference tissue model may not be applicable because of low target to background ratio for low affinity of [11C]PK-11195 to PBRs. We evaluated the PBRs binding with regions of interest (ROIs)-based approach to estimate total distribution volume (V). We used an integral from 0 min to 60 min (V60) as an estimate of V. On the coronal PET image, ROIs were placed on bilateral ST. Differences in right/left ST V60 ratios between lesioned and unlesioned control rats were compared using unpaired t tests. Immunohistochemical staining was performed for confirming the presence of activated microglia following decapitation on the PET experiment day.ResultsThe right/left ST V60 ratios in lesioned rats (1.07 ± 0.08) were significantly higher than those in unlesioned control rats (1.00 ± 0.06, P < 0.05). On immunohistochemical staining, activated microglia were exclusively observed in the injured right ST but not in the noninjured left ST of the injury rats and the bilateral ST of the non-injured control rats.ConclusionsThese results suggest that [11C]PK-11195 PET imaging would be a useful tool for evaluating microglial activation in a rat brain injury model.

Sentinel lymph node navigation surgery in Paget's disease of the vulva.

A 78-year-old woman with vulvar Pagets disease was examined with lymphoscintigraphy. Neither regional nor distant metastases nor inguinal or femoral lymph node metastases were evident clinically. Sentinel lymph nodes were identified before and during operation in both groin areas. The patient underwent selective sentinel lymph node sampling with a hand-held gamma probe and local vulvectomy. Histopathologic examination of the specimen revealed intraepithelial Pagets disease, and there was no evidence of cancer (stage T2N0M0). Postoperative lymphedema did not occur. The sentinel lymph node procedure for vulvar Pagets disease may be a promising technique for minimally invasive surgery.

Correlation between FEPPA uptake and microglia activation in 6-OHDA injured rat brain

Objectives: Neuroinflamation process along with degenerative disorders such as Alzheimer or Parkinson disease is believed to be measured with a radioligand for peripheral benzodiazepine receptor (PBR). We recently reported uptake of a PBR ligand, [C]PK11195 correlates microglia activation indices in a rat artificial inflammation model. We report here correlation between uptake of a novel PBR ligand, [F]FEPPA 2) 3) and the microglia activation in 6-hydroxdopamine (6-OHDA) treated rat brain.

Simple and low-cost tele-nuclear medicine conference system with the e-mail protocol

Purpose: Because of the recent innovative growth in computer technology, digital imaging, and the Internet, we can take advantage of these facilities for education and clinical work in nuclear medicine. We developed a tele-nuclear medicine conference system with electronic mail (e-mail) on the Internet.Methods: Twenty-one physicians (20 radiologists, 1 neurologist), 6 technologists and 2 medical students in six university hospitals (Japan 5, Canada 1), 5 local hospitals in Japan participated in this project. We used digital still cameras (330k pixels) equipped with a floppy disk drive and 10 x optical zoom to digitize images with JPEG compression (640×480 matrix). The images were attached to e-mail messages (containing a brief description of each case). The mail was sent simultaneously to all members on the mailing list. Scintigram and SPECT images as well as other radiological images were sent by e-mail. Reply mails about each case were sent to all members via the mailing list.Results: During a period of 6 months, 18 cases (tumor/infection: 7, bone: 6, cardiovascular: 1, neurology; 3, endocrine: 1) with 144 e-mails (average 5.6/case) were submitted to the conference. The average period of discussion was 15.6 days. The number of attached images was 1 to 9 (average, 4.2/e-mails). JPEG compression rate was 1/10 to 1/20. The quality of the images was good enough for discussion. Some cases required additional images for further discussion.Conclusion: Our tele-nuclear medicine conference with an electronic mailing list and digital camera was simple and low-cost. The conference system was useful for education and clinical work.