A lack of coupling between microglial activation and amyloid deposits may indicate that Aβ accumulation shown by [(11)C]PIB is not always the primary cause of microglial activation, but rather the negative correlation present in the PCC suggests that microglia can show higher activation during the production of Aβ in early AD.
Whether preclinical depression is one of the pathophysiologic features of Alzheimer disease (AD) has been under debate. In vivo molecular imaging helps clarify this kind of issue. Here, we examined in vivo changes in the brain serotoninergic system and glucose metabolism by scanning early-to moderate-stage AD patients with and without depression using PET with a radiotracer for the serotonin transporter, 11 C-3-amino-4-(2-dimethylaminomethylphenylsulfanyl) benzonitrile (DASB), and a metabolic marker, 18 F-FDG. Methods: Fifteen AD patients (8 nondepressed and 7 depressed) and 10 healthy subjects participated. All participants underwent 3-dimensional MRI and quantitative 11 C-DASB PET measurements, followed by 18 F-FDG PET scans in the AD group. Region-of-interest analysis was used to examine changes in 11 C-DASB binding potential estimated quantitatively by the Logan plot method in the serotonergic projection region. In addition, statistical parametric mapping was used to examine whether glucose metabolism in any brain region correlated with levels of 11 C-DASB binding in the dense serotonergic projection region (striatum) in AD. Results: Psychologic evaluation showed that general cognitive function (Mini-Mental State Examination) was similar between the 2 AD subgroups. Striatal 11 C-DASB binding was significantly lower in AD patients, irrespective of depression, than in healthy controls (P , 0.05, corrected), and 11 C-DASB binding in other dense projection areas decreased significantly in the depressive group, compared with the control group. The 11 C-DASB binding potential levels in the subcortical serotonergic projection region correlated negatively with depression score (Spearman correlation, P , 0.01) but not with dementia score. Statistical parametric mapping correlation analysis showed that glucose metabolism in the right dorsolateral prefrontal cortex was positively associated with the level of striatal 11 C-DASB binding in AD. Conclusion: The significant reduction in 11 C-DASB binding in nondepressed AD patients suggests that presynaptic serotonergic function is altered before the development of psychiatric problems such as depression in AD. The depressive AD group showed greater and broader reductions in binding, suggesting that a greater loss of serotonergic function relates to more severe psychiatric symptoms in the disease. This serotonergic dysfunction may affect the activity of the right dorsolateral prefrontal cortex, a higher center of cognition and emotion in AD. Al zheimer disease (AD) is a neurodegenerative disorder with progressive memory and cognitive deterioration followed by or concomitant with psychologic problems such as depression and hallucination, which have a strong negative impact on the course of the disease. The occurrence of these psychologic disturbances has been reported to closely relate to disruption of the serotonergic system (1). Loss of neurons in the serotonergic raphe nuclei (2) and dysfunction of its nerve terminals in the neocortex (3) have been reported in AD. Many li...
The prognosis for patients with pancreatic cancer is extremely poor. 1,2 Surgical resection is the only curative treatment option for these patients; nevertheless, most patients succumb to the disease due to local and distant recurrence. Neoadjuvant chemoradiotherapy (NAC-RT) was introduced to reduce tumor size and shrink vascular invasion in the vicinity of a tumor before surgery with the intent of improving the radical resection (R0 resection) rate. [3][4][5] However, obstructive jaundice is one of the primary symptoms of pancreatic head cancer, and NAC-RT in such cases would be time-consuming because of the need to maintain biliary drainage. We have been actively performing NAC-RT and have previously reported
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