The aim of this study was to evaluate the performance of ClairvivoPET using NEMA NU4 standards. The ClairvivoPET incorporates a LYSO dual depth-of-interaction detector system with 151 mm axial field ...of view (FOV). Spatial resolution, sensitivity, counting rate capabilities, and image quality were evaluated using NEMA NU4-2008 standards. Normal mouse imaging was also performed for 10 min after intravenous injection of (18)F(-)-NaF. Data were compared with 19 other preclinical PET scanners. Spatial resolution measured using full width at half maximum on FBP-ramp reconstructed images was 2.16 mm at radial offset 5 mm of the axial centre FOV. The maximum absolute sensitivity for a point source at the FOV centre was 8.72%. Peak noise equivalent counting rate (NECR) was 415 kcps at 14.6 MBq ml(-1). The uniformity with the image-quality phantom was 4.62%. Spillover ratios in the images of air and water filled chambers were 0.19 and 0.06, respectively. Our results were comparable with the 19 other preclinical PET scanners based on NEMA NU4 standards, with excellent sensitivity because of the large FOV. The ClairvivoPET with iterative reconstruction algorithm also provided sufficient visualization of the mouse spine. The high sensitivity and resolution of the ClairvivoPET scanner provided high quality images for preclinical studies.
Summary
A 59‐year‐old patient with diabetes mellitus had been treated with human recombinant insulin for 4 years. He developed a solid mass on his left abdomen at the insulin injection site, which ...had an overlying pigmented verrucous plaque and keratinized papules, similar to acanthosis nigricans (AN). On histological examination, the mass was found to contain a deposit of amyloid in the dermis, with hyperkeratosis, papillomatosis and acanthosis in the epidermis. Using immunohistochemistry, the amyloid deposits were found to be positive for insulin. A few cases of localized insulin‐derived amyloid deposits at injection sites have been reported previously, but none had significant epidermal changes. The coexistence of dermal insulin‐derived amyloidosis and an overlying AN‐like change, as found in our patient, has not been reported previously, to our knowledge. The presence of a tumour‐like lesion at the injection site should be carefully examined, as injection of insulin into amyloid deposits can result in insulin resistance.
Background and purpose
Corticobasal syndrome (CBS) is pathologically characterized by tau deposits in neuronal and glial cells and by reactive astrogliosis. In several neurodegenerative disorders, ...18F‐THK5351 has been observed to bind to reactive astrocytes expressing monoamine oxidase B. In this study, the aim was to investigate the progression of disease‐related pathology in the brains of patients with CBS using positron emission tomography with 18F‐THK5351.
Methods
Baseline and 1‐year follow‐up imaging were acquired using magnetic resonance imaging and positron emission tomography with 18F‐THK5351 in 10 subjects: five patients with CBS and five age‐matched normal controls (NCs).
Results
The 1‐year follow‐up scan images revealed that 18F‐THK5351 retention had significantly increased in the superior parietal gyrus of the patients with CBS compared with the NCs. The median increases in 18F‐THK5351 accumulation in the patients with CBS were 6.53% in the superior parietal gyrus, 4.34% in the precentral gyrus and 4.33% in the postcentral gyrus. In contrast, there was no significant increase in the regional 18F‐THK5351 retention in the NCs.
Conclusions
Longitudinal increases in 18F‐THK5351 binding can be detected over a short interval in the cortical sites of patients with CBS. A monoamine oxidase B binding radiotracer could be useful in monitoring the progression of astrogliosis in CBS.
The formation of neurofibrillary tangles is believed to contribute to the neurodegeneration observed in Alzheimer's disease (AD). Postmortem studies have shown strong associations between the ...neurofibrillary pathology and both neuronal loss and the severity of cognitive impairment. However, the temporal changes in the neurofibrillary pathology and its association with the progression of the disease are not well understood. Tau positron emission tomography (PET) imaging is expected to be useful for the longitudinal assessment of neurofibrillary pathology in the living brain. Here, we performed a longitudinal PET study using the tau-selective PET tracer 18FTHK-5117 in patients with AD and in healthy control subjects. Annual changes in 18FTHK-5117 binding were significantly elevated in the middle and inferior temporal gyri and in the fusiform gyrus of patients with AD. Compared to patients with mild AD, patients with moderate AD showed greater changes in the tau load that were more widely distributed across the cortical regions. Furthermore, a significant correlation was observed between the annual changes in cognitive decline and regional 18FTHK-5117 binding. These results suggest that the cognitive decline observed in patients with AD is attributable to the progression of neurofibrillary pathology. Longitudinal assessment of tau pathology will contribute to the assessment of disease progression and treatment efficacy.
Results Brain regions more activated by the major key than the minor key when presented with the identical motion film were the left cerebellum, the right fusiform gyrus, the right superior ...occipital, the left superior orbito frontal, the right pallidum, the left precuneus, and the bilateral thalamus.
Lower gastrointestinal perforation is rare and challenging to diagnose in patients presenting with an acute abdomen. However, no study has examined the frequency and associated factors of diagnostic ...errors related to lower gastrointestinal perforation. This large-scale multicenter retrospective study investigated the frequency of diagnostic errors and identified the associated factors. Factors at the level of the patient, symptoms, situation, and physician were included in the analysis. Data were collected from nine institutions, between January 1, 2015 and December 31, 2019. Timely diagnosis was defined as diagnosis at the first visit in computed tomography (CT)-capable facilities or referral to an appropriate medical institution immediately following the first visit to a non-CT-capable facility. Cases not meeting this definition were defined as diagnostic errors that resulted in delayed diagnosis. Of the 439 cases of lower gastrointestinal perforation identified, delayed diagnosis occurred in 138 cases (31.4%). Multivariate logistic regression analysis revealed a significant association between examination by a non-generalist and delayed diagnosis. Other factors showing a tendency with delayed diagnosis included presence of fever, absence of abdominal tenderness, and unavailability of urgent radiology reports. Initial misdiagnoses were mainly gastroenteritis, constipation, and small bowel obstruction. In conclusion, diagnostic errors occurred in about one-third of patients with a lower gastrointestinal perforation.
Cold adaptation is one of the most important functions for the human. In this study we focused on its relationship to mitochondria. The mitochondrion itself exists in human cells and has a vital ...function in generating ATP and heat. Mitochondria have their own genome, which enables modern humans to classify the mitochondria haplogroup. Recent studies have suggested that these haplogroups were shaped by climatic change and the mitochondrial genome influence balance between ATP and heat generation. In this study we hypothesized that human cold adaptability is influenced by the mitochondrial haplogroup. Our purpose was to investigate the association between mitochondrial haplogroup and psychophysiological responses during cold exposure. We focus on haplogroup D, the biggest group in Japan and also a major group in northern Asia, including Siberia. Subjects were 18 young Japanese university students divided into two groups: the D group and the non-D group. There was no significant difference of height, weight, BMI, or BSA between them. Cold exposure was induced for 90 minutes in a climatic chamber; for the first 30 minutes, the air temperature was decreased from 27℃ to 10℃ and, for the last 60 minutes, the temperature was maintained at 10℃. Rectal and skin temperatures, oxygen consumption (VO2), blood pressure, and thermal comfortability were measured during the experiment. The result showed that the D group had significantly higher Tre during cold exposure (p<0.001), with no significant difference in VO2 and mean skin temperature. This suggests that mitochondrial haplogroup D is associated with cold resistance and haplogroup.
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![[O29] Relationship between ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1880-6791/small "[O29] Relationship between mitochondrial haplogroup and psychophysiological responses during cold exposure in Japanese subjects")