Cerebral glucose metabolism in dizygotic twin pairs discordant for Alzheimer's disease

Positron emission tomography (PET) with 2-deoxy-2[(18)F]-fluoro-D-glucose (FDG) can be used to estimate regional cerebral glucose metabolism (rCMRgluc). FDG-PET studies have shown rCMRgluc to be reduced especially in temporal and parietal cortices in Alzheimer's disease (AD). A previous study on monozygotic twins discordant for AD showed that the rCMRgluc of the non-demented twins is reduced significantly in the lateral temporal and parietal cortices compared to unrelated controls. In this study we examined 9 pairs of dizygotic twins discordant for AD with FDG-PET. The rCMRgluc of the demented twins was 16% lower in the prefrontal cortex (p = 0.04), 20% lower in the hippocampus (p = 0.002) and 15% lower in the lateral temporal cortex (p = 0.003) compared to controls. The non-demented twins showed no such reductions on any cortical region compared to unrelated control subjects. This implies that both genes and environment, and not genes alone, are causative in the pathogenesis of AD.     

Genomic and epidemiological report of the recombinant XJ lineage SARS-CoV-2 variant,detected in northern Finland,January 2022

Recombinant sequences of the SARS-CoV-2 Omicron variant were detected in surveillance samples collected in north-western Finland in January 2022. We detected 191 samples with an identical genome arrangement in weeks 3 to 11, indicating sustained community transmission. The recombinant lineage has a 5’-end of BA.1, a recombination breakpoint between orf1a and orf1b (nucleotide position 13,296–15,240) and a 3’-end of BA.2 including the S gene. We describe the available genomic and epidemiological data about this currently circulating recombinant XJ lineage.