Quantitative assessment of amygdala in Macaca fascicularis monkeys.

The amygdaloid complex (AC) is involved in very relevant cognitive and emotional pathways and exhibits changes in aging and in some neurological and psychiatric disorders. The quantitative estimators of AC could be useful to understand the impact of amygdaloid pathology in these processes, both globally and for each nucleus in particular, and their neurons. The present study analyzes morphometric and stereological estimators in the whole AC and its three main nuclei (lateral [La], basal [Ba], and accessory basal [AB]) in six Macaca fascicularis monkeys. All the brains were fixed and sectioned in the coronal plane; Nissl-stained sections were used for estimation of size and form parameters in both, the AC, and the La, Ba, and AB nuclei separately. The study includes stereological estimates of the volume and surface area of the AC; also, volume of the neurons in the amygdaloid nuclei was estimated using the point-sampled intercepts method. Our results show that the AB nucleus is smaller than both the La and Ba nuclei in both morphometric and stereological estimators. Brain hemispheric side had not significant influence on any of quantitative estimates. The neuron volume was higher in the AB nucleus relative to LA and Ba of the nuclei. These data describe some quantitative parameters of the amygdaloid complex and their main nuclei that could help us to detect small changes in neurodegenerative and other pathological processes.

A Case Series of Stent Thrombosis During the COVID-19 Pandemic.

Coronavirus disease-2019 (COVID-19) triggers a hypercoagulable state with a high incidence of thrombotic complications. We have noted a higher than expected incidence of stent thrombosis in these patients. (Level of Difficulty: Intermediate.).

WITHDRAWN:A Case Series of Stent Thrombosis During the COVID-19 Pandemic.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.jaccas.2020.05.024. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Neuronal volume of the hippocampal regions in ageing.

The hippocampal formation (HF) has an important role in different human capacities, such as memory processing and emotional expression. Both extensive changes and limited variations of its components can cause clinically expressed dysfunctions. Although there remains no effective treatment for diseases caused by pathological changes in this brain region, detection of these changes, even minimally, could allow us to develop early interventions and establish corrective measures. This study analysed the neuronal islands of layer II of the entorhinal cortex (EC), the neuronal clumps of the external principal layer of the presubiculum (PrS) and the dentate granule cells of the dentate gyrus (DG), which represent the prominent structural regions within the HF circuit. Subjects from two age groups (younger or older than 65 years) were studied and their neuronal size assessed by the point-sampled intercepts stereological method. The quantitative v¯v(soma) estimate was a volume of roughly 8,500 µm3 for EC layer II neurons, and DG granule neurons and presubicular neurons were five and 10 times smaller, respectively. The older age group showed a v¯v(soma) increase of 2%, 18% and 28% with respect to the younger group in the PrS, DG and EC regions, respectively. None of these regions showed interhemispheric differences. This quantitative estimation is relevant because the observed variance in the v¯v(soma) estimates suggests that biological variation is the main contributory factor, with intercepts and measurements having a smaller impact. Therefore, we suggest that age has a limited influence on neuronal volume variation in these HF regions, which needs to be compared with similar measurements in neurodegenerative disorders such as Alzheimer's.