Clinical Research on Alzheimer's Disease: Progress and Perspectives / 神经科学通报·英文版

Alzheimer's disease (AD), the most common type of dementia, is becoming a major challenge for global health and social care. However, the current understanding of AD pathogenesis is limited, and no early diagnosis and disease-modifying therapy are currently available. During the past year, significant progress has been made in clinical research on the diagnosis, prevention, and treatment of AD. In this review, we summarize the latest achievements, including diagnostic biomarkers, polygenic hazard score, amyloid and tau PET imaging, clinical trials targeting amyloid-beta (Aβ), tau, and neurotransmitters, early intervention, and primary prevention and systemic intervention approaches, and provide novel perspectives for further efforts to understand and cure the disease.

Computed tomographic features of the feline brain change with advancing age? / O aspecto tomográfico do encéfalo de felinos altera com o avanço da idade?

A better understanding of normal or expected encephalic changes with increasing age in cats is needed as a growing number of these animals is attended in veterinary clinics, and imaging data referring to normal age-associated changes are extremely scarce in the literature. The objective of this study was to identify age-related changes in feline brain using CT imaging. Fifteen non-brachycephalic healthy cats with age between 1 to 6 years (adult group) and others over 12 years (geriatric group) were submitted to CT scan of the brain. Statistically significant differences were found between the groups for the ability to identify the left lateral ventricle and for falx cerebri calcification, both identified in a greater number of cats of the geriatric group. A significantly higher mean width of the third ventricle was also detected in geriatric animals. There were no statistically significant differences between lateral ventricular dimensions and encephalic parenchymal attenuation on pre and post-contrast CT phases. The results of the present study show an increase in the incidence of falx cerebri calcification and a third ventricular dilatation with advancing age in cats. Future researches using MRI scanners and a greater quantity of cats are needed in order to identify supplementary age-related changes.(AU)

Uma melhor compreensão das alterações encefálicas normais ou esperadas com o aumento da idade em gatos é necessária no presente momento, uma vez que tem havido um número crescente desses animais nas clínicas veterinárias, e dados de imagem referentes às alterações normais associadas à idade são extremamente escassos na literatura. O objetivo deste estudo foi a identificação de alterações relacionadas à idade no encéfalo de gatos através da tomografia computadorizada. Quinze gatos saudáveis não braquicefálicos com idade entre 1 e 6 anos (grupo adulto) e mais de 12 anos (grupo geriátrico) foram submetidos à tomografia encefálica. Diferenças estatísticas significativas foram encontradas entre os grupos para a identificação do ventrículo lateral esquerdo e calcificação da foice cerebral, ambos visualizados em um número maior de gatos do grupo geriátrico. A média de largura do terceiro ventrículo também foi significativamente maior nos animais geriátricos. Não foram encontradas diferenças estatísticas significativas entre a mensuração dos ventrículos laterais e a atenuação do parênquima encefálico nas fases tomográficas pré e pós-contraste. Os resultados do presente estudo demonstram aumento da incidência de calcificação da foice cerebral e dilatação do terceiro ventrículo de acordo com o avanço da idade em gatos. Pesquisas futuras utilizando ressonância magnética e uma maior quantidade de gatos são necessárias a fim de se identificar alterações complementares relacionadas à idade.(AU)

Computed tomographic features of the feline brain change with advancing age?

Abstract: A better understanding of normal or expected encephalic changes with increasing age in cats is needed as a growing number of these animals is attended in veterinary clinics, and imaging data referring to normal age-associated changes are extremely scarce in the literature. The objective of this study was to identify age-related changes in feline brain using CT imaging. Fifteen non-brachycephalic healthy cats with age between 1 to 6 years (adult group) and others over 12 years (geriatric group) were submitted to CT scan of the brain. Statistically significant differences were found between the groups for the ability to identify the left lateral ventricle and for falx cerebri calcification, both identified in a greater number of cats of the geriatric group. A significantly higher mean width of the third ventricle was also detected in geriatric animals. There were no statistically significant differences between lateral ventricular dimensions and encephalic parenchymal attenuation on pre and post-contrast CT phases. The results of the present study show an increase in the incidence of falx cerebri calcification and a third ventricular dilatation with advancing age in cats. Future researches using MRI scanners and a greater quantity of cats are needed in order to identify supplementary age-related changes.

Resumo: Uma melhor compreensão das alterações encefálicas normais ou esperadas com o aumento da idade em gatos é necessária no presente momento, uma vez que tem havido um número crescente desses animais nas clínicas veterinárias, e dados de imagem referentes às alterações normais associadas à idade são extremamente escassos na literatura. O objetivo deste estudo foi a identificação de alterações relacionadas à idade no encéfalo de gatos através da tomografia computadorizada. Quinze gatos saudáveis não braquicefálicos com idade entre 1 e 6 anos (grupo adulto) e mais de 12 anos (grupo geriátrico) foram submetidos à tomografia encefálica. Diferenças estatísticas significativas foram encontradas entre os grupos para a identificação do ventrículo lateral esquerdo e calcificação da foice cerebral, ambos visualizados em um número maior de gatos do grupo geriátrico. A média de largura do terceiro ventrículo também foi significativamente maior nos animais geriátricos. Não foram encontradas diferenças estatísticas significativas entre a mensuração dos ventrículos laterais e a atenuação do parênquima encefálico nas fases tomográficas pré e pós-contraste. Os resultados do presente estudo demonstram aumento da incidência de calcificação da foice cerebral e dilatação do terceiro ventrículo de acordo com o avanço da idade em gatos. Pesquisas futuras utilizando ressonância magnética e uma maior quantidade de gatos são necessárias a fim de se identificar alterações complementares relacionadas à idade.

Endodontic management of a maxillary first molar with three roots and seven root canals with the aid of cone-beam computed tomography

Variation in root canal morphology, especially in maxillary first molar presents a constant challenge for a clinician in their detection and management. This case report describes the successful root canal treatment of a three rooted right maxillary first molar presenting with three canals each in the mesiobuccal and distobuccal roots and one canal in the palatal root. The clinical detection of this morphologic aberration was made using a dental operating microscope, and the canal configuration was established after correlating and computing the clinical, radiographic and cone-beam computed tomography (CBCT) scan findings. CBCT images confirmed the configuration of the canals in the mesiobuccal and distobuccal roots to be Al-Qudah and Awawdeh type (3-2) and type (3-2-1), respectively, whereas the palatal root had a Vertucci type I canal pattern. This report reaffirms the importance of careful examination of the floor of the pulp chamber with a dental operating microscope and the use of multiangled preoperative radiographs along with advanced diagnostic aids such as CBCT in identification and successful management of aberrant canal morphologies.

Digital Tomosynthesis of the Chest: Comparison of Patient Exposure Dose and Image Quality between Standard Default Setting and Low Dose Setting

OBJECTIVE: To determine the optimum low dose (LD) digital tomosynthesis (DT) setting, and to compared the image quality of the LD DT with that of the standard default (SD) DT. MATERIALS AND METHODS: Nine DT settings, by changing tube voltage, copper filter, and dose ratio, were performed for determining the LD setting. Among combinations of DT setting, a condition providing the lowest radiation dose was determined. Eighty artificial nodules less than 1 cm in diameter (subcentimeter nodules: 40, micronodules less than 4 mm: 40) were attached to a Styrofoam and a diaphragm of the phantom. Among these, 38 nodules were located at the periphery of the lung (thin area) and 42 nodules were located at the paravertebral or sub-diaphragmatic area (thick area). Four observers counted the number of nodules detected in the thick and thin areas. The detection sensitivity in SD and LD settings were calculated separately. Data were analyzed statistically. RESULTS: The lowest LD setting was a combination of 100 kVp, 0.3 mm additional copper filter, and a 1 : 5 dose ratio. The effective dose for the LD and SD settings were 62 microSv and 140 microSv, separately. A 56.7% dose reduction was achieved in the LD setting compared with the SD setting. Detection sensitivities were not different between the SD and the LD settings except between observers 1 and 2 for the detection of micronodules in the thick area. CONCLUSION: LD DT can be effective in nodule detection bigger than 4 mm without a significant decrease in image quality compared with SD DT.