Abstract
The human cerebral cortex is one of the most evolved regions of the brain, responsible for most higher-order neural functions. Since nerve cells (together with synapses) are the processing ...units underlying cortical physiology and morphology, we studied how the human neocortex is composed regarding the number of cells as a function of sex and age. We used the isotropic fractionator for cell quantification of immunocytochemically labeled nuclei from the cerebral cortex donated by 43 cognitively healthy subjects aged 25–87 years old. In addition to previously reported sexual dimorphism in the medial temporal lobe, we found more neurons in the occipital lobe of men, higher neuronal density in women’s frontal lobe, but no sex differences in the number and density of cells in the other lobes and the whole neocortex. On average, the neocortex has ~10.2 billion neurons, 34% in the frontal lobe and the remaining 66% uniformly distributed among the other 3 lobes. Along typical aging, there is a loss of non-neuronal cells in the frontal lobe and the preservation of the number of neurons in the cortex. Our study made possible to determine the different degrees of modulation that sex and age evoke on cortical cellularity.
Abstract Onchocerca lupi (Spirurida, Onchocercidae) is an emerging vector-borne helminth that causes nodular lesions associated with acute or chronic ocular disease in dogs and cats. Since its first ...description in dogs in 1991, this zoonotic filarioid has been increasingly reported in Europe and the United States. An 8-year-old outdoor mixed-breed female dog from the Algarve (southern Portugal) was presented with a history of severe dyspnoea. Cervical and thoracic radiographs revealed a slight reduction in the diameter of the cervical trachea and a moderate increase in radiopacity of the laryngeal soft tissue. An exploratory laryngoscopy was performed, revealing filiform worms associated with stenosis of the thyroid cartilage and a purulent necrotic tissue in the larynx lumen. A single sessile nodule, protruding from the dorsal wall of the laryngeal lumen caused a severe reduction of the glottis and tracheal diameter. Fragments of the worms were morphologically and molecularly identified as O. lupi . Histological examination of the nodule showed a granulomatous reaction with sections of coiled gravid female nematodes. Following laryngoscopy, a tracheostomy tube was inserted to relieve dyspnoea and ivermectin (300 μg/kg, once a week, for 8 weeks) combined with prednisolone was prescribed. The dog showed a complete recovery. Although O. lupi has been isolated in human patients from the spinal cord, this is the first report of an aberrant migration of O. lupi in a dog. The veterinary medical community should pay attention to aberrant location of O. lupi and consider onchocercosis as a differential diagnosis for airway obstruction in dogs.
In this paper we aimed at describing the quantifiable properties diffusion tensor images: fractional anisotropy (FA) and Apparent Diffusion Coefficient (ADC) at white matter hyperintensities (WMH) ...areas found in situ postmortem (PM) specimens. Our hypothesis is that the properties of WMH would be different from normal appearing white matter (NAWM) in the DTI images in postmortem.
We analyzed PM MR images from 24 subjects (12 males; mean age: 67.2±14.7 years) and in vivo (IV) MR images from 10 healthy volunteers (5 males; mean age: 62.3±5.49 years). DTI processing was performed using the FSL platform; ROIs were placed at WMH and NAWM at FA and ADC maps.
PM group presented FA values 26.75% lower at WMH than in NAWM. IV Mean FA in WMH was also reduced (17.76%) compared to NAWM. Average ADC from PM subjects was 6.89% higher at WMH than NAWM and 12.51% higher at WMH than NAWM at IV group.
We have demonstrated that in situ postmortem FA values at WMH are lower than NAWM, similar to in vivo data. This indicates that DTI obtained at a short postmortem interval from PM MRI could be used to understand in vivo MRI data.
•DTI findings obtained from PM MRI could be used to understand IV data.•Our workflow is free from tissue fixation artifacts and MRI are obtained at short postmortem intervals.
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