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Background: Amyloid imaging with positron emission tomography (PET) often comes with glucose metabolic imaging in diagnosis of Alzheimer's disease (AD).Objective: The present purpose was to explore the clinical valence of early amyloid-β (Aβ) PET scans to determine whether they could substitute for other imaging biomarkers (early and delayed Aβ images of 11C-Pittsburgh compound B (PIB) and 18F-fluorodeoxyglucose (FDG) images) in the AD spectrum.Methods: Thirty healthy control subjects, 20 patients with mild cognitive impairment, and 45 patients with AD underwent 11C-PIB and 18F- FDG PET. Image analyses were performed with three-dimensional stereotactic surface projection and Brodmann's area regions-of-interest methods. Since early accumulation of PIB (ePIB) reflects blood flow, we classified all subjects according to the level of ePIB in the posterior cingulate gyrus, precuneus, and lateral parietal cortex. We compared the PET parameters (ePIB, delayed-phase PIB accumulation or dPIB, FDG) to determine whether ePIB-based categorization reflected Aβ deposition in a Braak stage-related fashion.Results: We found that ePIB images were similar to 18F-FDG images and that the progress of Aβ deposition deduced from the reduction in ePIB index was similar to the pathological progress of Braak staging. A decrease in the ePIB level in the posterior cingulate gyrus, precuneus, and parietal cortex was shown to correspond to greater and wider Aβ deposition in the medial frontal, anterior, and posterior cingulate gyri.Conclusions: The early-phase 11C-PIB index can be an alternative to the neurogenerative markers of glucose hypometabolism and reflects the Braak stage of Aβ deposition in the living AD brain. [ABSTRACT FROM AUTHOR]

Background: The α7 subtype of the nicotinic acetylcholine receptor (nAChR) is considered important in higher cognitive functions, and cholinergic loss underpins the pathophysiology of Alzheimer's disease (AD). However, the relationships between α7 nAChR function and clinical functions or amyloid-β (Aβ) deposition remain to be explored in the living AD brain.Objective: We aimed to elucidate the relationship between α7 nAChR availability in the specific cholinergic region and cognitive decline in the Aβ-confirmed AD brain.Methods: Twenty AD patients and ten age-matched healthy subjects were examined. The α7-nAChR availability and Aβ deposition were evaluated using positron emission tomography with an α7 nAChR radiotracer 11C-(R)-MeQAA and 11C-Pittsburg compound B (11C-PiB), respectively. Semi-quantified values of tracer binding were estimated with a simplified reference tissue method for BPND of 11C-(R)-MeQAA and a tissue ratio method for SUVR of 11C-PiB. These parameters and clinical scores were compared voxel-wise using a statistical parametric mapping method.Results: The levels of 11C-(R)-MeQAA BPND in the temporal and prefrontal cholinergic projection regions were significantly lower in AD, and negative correlations were found between 11C-PiB SUVR and 11C-(R)-MeQAA BPND in the region of the nucleus basalis magnocellularis and medial prefrontal cortex. Levels of 11C-(R)-MeQAA BPND were significantly correlated with memory and frontal function scores in AD.Conclusion: The association between Aβ burden and α7-nAChR reduction in the basal forebrain cholinergic system was highlighted in relation to cognitive decline in AD. This suggests that Aβ-linked α7-nAChR reduction is clinico-pathophyisologically important for considering a good therapeutic target in AD. [ABSTRACT FROM AUTHOR]

Objective: Subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease is effective; however, its mechanism is unclear. To investigate the degree of neuronal terminal survival after STN-DBS, the authors examined the striatal dopamine transporter levels before and after treatment in association with clinical improvement using PET with [11C]2β-carbomethoxy-3β-(4-fluorophenyl)tropane ([11C]CFT)., Methods: Ten patients with Parkinson's disease who had undergone bilateral STN-DBS were scanned twice with [11C]CFT PET just before and 1 year after surgery. Correlation analysis was conducted between [11C]CFT binding and off-period Unified Parkinson's Disease Rating Scale (UPDRS) scores assessed preoperatively and postoperatively., Results: [11C]CFT uptake reduced significantly in the posterodorsal putamen contralateral to the parkinsonism-dominant side after 1 year; however, an increase was noted in the contralateral anteroventral putamen and ipsilateral ventral caudate postoperatively (p < 0.05). The percentage increase in [11C]CFT binding was inversely correlated with the preoperative binding level in the bilateral anteroventral putamen, ipsilateral ventral caudate, contralateral anterodorsal putamen, contralateral posteroventral putamen, and contralateral nucleus accumbens. The percentage reduction in UPDRS-II score was significantly correlated with the percentage increase in [11C]CFT binding in the ipsilateral anteroventral putamen (p < 0.05). The percentage reduction in UPDRS-III score was significantly correlated with the percentage increase in [11C]CFT binding in the ipsilateral anteroventral putamen, ventral caudate, and nucleus accumbens (p < 0.05)., Conclusions: STN-DBS increases dopamine transporter levels in the anteroventral striatum, which is correlated with the motor recovery and possibly suggests the neuromodulatory effect of STN-DBS on dopaminergic terminals in Parkinson's disease patients. A preoperative level of anterior striatal dopamine transporter may predict reserve capacity of STN-DBS on motor recovery.

A 69-year-old female developed subacute diplopia, right peripheral facial nerve palsy, bilateral upper and lower extremities dysesthesia and weakness 50 years after silicone injection for breast augmentation. Motor conduction study revealed prolonged distal latency and reduced amplitude in the median, ulnar, and peroneal nerves. Sensory conduction velocities were reduced in the median and ulnar nerves, and sensory potential in the sural nerve could not be recorded. While intravenous immunoglobulin therapy was ineffective, explantation of silicone breast implants improved her neurological symptoms. Histopathological study of axillary lymph node revealed foreign body granulomas and macrophages phagocyting silicone. The patient was diagnosed with human adjuvant disease presenting clinical features of Guillain-Barré syndrome. Human adjuvant disease should be considered in the patients with implants like silicone and neurological symptoms.

The presence of activated microglia in the brains of healthy elderly people is a matter of debate. We aimed to clarify the degree of microglial activation in aging and dementia as revealed by different tracers by comparing the binding potential (BP ND ) in various brain regions using a first-generation translocator protein (TSPO) tracer [ 11 C]( R)PK11195 and a second-generation tracer [ 11 C]DPA713. The BP ND levels, estimated using simplified reference tissue models, were compared among healthy young and elderly individuals and patients with Alzheimer's disease (AD) and were correlated with clinical scores. An analysis of variance showed category-dependent elevation in levels of [ 11 C]DPA713 BP ND in all brain regions and showed a significant increase in the AD group, whereas no significant changes among groups were found when [ 11 C]( R)PK11195 BP ND was used. Cognito-mnemonic scores were significantly correlated with [ 11 C]DPA713 BP ND levels in many brain regions, whereas [ 11 C]( R)PK11195 BP ND failed to correlate with the scores. As mentioned elsewhere, the present results confirmed that the second-generation TSPO tracer [ 11 C]DPA713 has a greater sensitivity to TSPO in both aging and neuronal degeneration than [ 11 C]( R)PK11195. Positron emission tomography with [ 11 C]DPA713 is suitable for the delineation of in vivo microglial activation occurring globally over the cerebral cortex irrespective of aging and degeneration.

EPHA7 is a member of the EPHA family of receptor kinases, among which several members are known to be involved in human lung carcinogenesis. We report here a novel spliced variant, the so-called secreted form of EPHA7, recently reported in malignant lymphoma, in human lung cancer cell lines and primary lung cancer. In contrast to the EPHA7 down-regulation in colorectal cancer by promoter hypermethylation, EPHA7 is expressed at a substantial level in most human lung cancers and the secreted form of EPHA7 mRNA was found in a fraction of primary lung cancer tissues, lung cancer cell lines, and immortalized bronchogenic epithelial cell lines. Interestingly, the secreted form of EPHA7 message was predominantly detected in non-adeno type lung carcinoma. The mechanistic role of the secreted form of EPHA7 in human lung carcinogenesis is not clear, but the presence of this form could distinctly exclude adenocarcinoma of the lung from the other categories, i.e., squamous cell carcinoma, small cell carcinoma and large cell carcinoma, which have strong association with smoking. This is the first study to detect the secreted form of EPHA7 in human epithelial tissues. EPHA7 warrants further investigation to determine its possible involvement in smoking related lung carcinogenesis.