The role of the amygdala in ictal central apnea: insights from brain MRI morphometry

OBJECTIVE

Ictal central apnea (ICA) is a frequent correlate of focal seizures, particularly in temporal lobe epilepsy (TLE), and regarded as a potential electroclinical biomarker of sudden unexpected death in epilepsy (SUDEP). Aims of this study are to investigate morphometric changes of subcortical structures in ICA patients and to find neuroimaging biomarkers of ICA in patients with focal epilepsy.

METHODS

We prospectively recruited focal epilepsy patients with recorded seizures during a video-EEG long-term monitoring with cardiorespiratory polygraphic recordings from April 2020 to September 2022. Participants were accordingly subdivided into two groups: patients with focal seizures with ICA (ICA) and without (noICA). A pool of 30 controls matched by age and sex was collected. All the participants underwent MRI scans with volumetric high-resolution T1-weighted images. Post-processing analyses included a whole-brain VBM analysis and segmentation algorithms performed with FreeSurfer.

RESULTS

Forty-six patients were recruited (aged 15-60 years): 16 ICA and 30 noICA. The whole-brain VBM analysis showed an increased gray matter volume of the amygdala ipsilateral to the epileptogenic zone (EZ) in the ICA group compared to the noICA patients. Amygdala sub-segmentation analysis revealed an increased volume of the whole amygdala, ipsilateral to the EZ compared to controls [F(1, 76) = 5.383, pFDR = 0.042] and to noICA patients ([F(1, 76) = 5.383, pFDR = 0.038], specifically of the basolateral complex (respectively F(1, 76) = 6.160, pFDR = 0.037; F(1, 76) = 5.121, pFDR = 0.034).

INTERPRETATION

Our findings, while confirming the key role of the amygdala in participating in ictal respiratory modifications, suggest that structural modifications of the amygdala and its subnuclei may be valuable morphological biomarkers of ICA.

Amide Bonds Meet Flow Chemistry: A Journey into Methodologies and Sustainable Evolution

Formation of amide bonds is of immanent importance in organic and synthetic medicinal chemistry. Its presence in "traditional" small-molecule active pharmaceutical ingredients, in linear or cyclic oligo- and polypeptidic actives, including pseudopeptides, has led to the development of dedicated synthetic approaches for the formation of amide bonds starting from, if necessary, suitably protected amino acids. While the use of solid supported reagents is common in traditional peptide synthesis, similar approaches targeting amide bond formation in continuous-flow mode took off more significantly, after a first publication in 2006, only a couple of years ago. Most efforts rely upon the transition of traditional approaches in flow mode, or the combination of solid-phase peptide synthesis principles with flow chemistry, and advantages are mainly seen in improving space-time yields. This Review summarizes and compares the various approaches in terms of basic amide formation, peptide synthesis, and pseudopeptide generation, describing the technological approaches and the advantages that were generated by the specific flow approaches. A final discussion highlights potential future needs and perspectives in terms of greener and more sustainable syntheses.

5S-IGS rDNA in wind-pollinated trees (Fagus L.) encapsulates 55 million years of reticulate evolution and hybrid origins of modern species

Standard models of plant speciation assume strictly dichotomous genealogies in which a species, the ancestor, is replaced by two offspring species. The reality in wind-pollinated trees with long evolutionary histories is more complex: species evolve from other species through isolation when genetic drift exceeds gene flow; lineage mixing can give rise to new species (hybrid taxa such as nothospecies and allopolyploids). The multi-copy, potentially multi-locus 5S rDNA is one of few gene regions conserving signal from dichotomous and reticulate evolutionary processes down to the level of intra-genomic recombination. Therefore, it can provide unique insights into the dynamic speciation processes of lineages that diversified tens of millions of years ago. Here, we provide the first high-throughput sequencing (HTS) of the 5S intergenic spacers (5S-IGS) for a lineage of wind-pollinated subtropical to temperate trees, the Fagus crenata - F. sylvatica s.l. lineage, and its distant relative F. japonica. The observed 4963 unique 5S-IGS variants reflect a complex history of hybrid origins, lineage sorting, mixing via secondary gene flow, and intra-genomic competition between two or more paralogous-homoeologous 5S rDNA lineages. We show that modern species are genetic mosaics and represent a striking case of ongoing reticulate evolution during the past 55 million years.

COVID-19 and vertical transmission: assessing the expression of ACE2/TMPRSS2 in the human fetus and placenta to assess the risk of SARS-CoV-2 infection

BACKGROUND

Pregnant women have been identified as a potentially at-risk group concerning COVID-19 infection, but little is known regarding the susceptibility of the fetus to infection. Co-expression of ACE2 and TMPRSS2 has been identified as a prerequisite for infection, and expression across different tissues is known to vary between children and adults. However, the expression of these proteins in the fetus is unknown.

METHODS

We performed a retrospective analysis of a single cell data repository. The data were then validated at both gene and protein level by performing RT-qPCR and two-colour immunohistochemistry on a library of second-trimester human fetal tissues.

FINDINGS

TMPRSS2 is present at both gene and protein level in the predominantly epithelial fetal tissues analysed. ACE2 is present at significant levels only in the fetal intestine and kidney, and is not expressed in the fetal lung. The placenta also does not co-express the two proteins across the second trimester or at term.

INTERPRETATION

This dataset indicates that the lungs are unlikely to be a viable route of SARS-CoV2 fetal infection. The fetal kidney, despite presenting both the proteins required for the infection, is anatomically protected from the exposure to the virus. However, the gastrointestinal tract is likely to be susceptible to infection due to its high co-expression of both proteins, as well as its exposure to potentially infected amniotic fluid.

TWEETABLE ABSTRACT

This work provides detailed mechanistic insight into the relative protection & vulnerabilities of the fetus & placenta to SARS-CoV-2 infection by scRNAseq & protein expression analysis for ACE2 & TMPRSS2. The findings help to explain the low rate of vertical transmission.

Socio-cognitive processing in people with eating disorders: Computerized tests of mentalizing, empathy and imitation skills

OBJECTIVE

Eating disorders are psychiatric illnesses characterized by extreme eating behaviors, such as sustained food restriction or loss of control over eating. Symptoms are thought to be maintained by a variety of mechanisms, one of which may be the socio-cognitive impairments associated with eating disorders. While some previous work has addressed socio-cognitive impairments in eating disorders, this work has relied mostly on self-report data.

METHOD

Here we employed computerized tests of (a) mentalizing (ability to infer the mental states of others); (b) empathy (the degree to which the emotional states of others can be identified and the degree to which the states of others impact one's own emotional state); and (c) imitation (the degree to which observation of another's actions prompts the performance of those actions); in a group of 78 women with an eating disorder and a matched control group of 66 healthy women.

RESULTS

People with eating disorders showed both hyper- and hypo-mentalizing and reduced accuracy of emotional and cognitive mental state inference. They displayed less imitation of observed actions, but no differences in empathy compared to healthy controls. Although anxiety and depressive symptoms had significant effects on mentalizing, most of the observed inter-group differences persisted.

DISCUSSION

Women with eating disorders have difficulties mentalizing and imitating observed actions despite intact non-social automatic imitation, compared to healthy controls. These findings provide an indication that intervention modules to strengthen specific areas of social cognition might be helpful to improve patients' social skills.