Gut Dysbiosis in Cutaneous T-Cell Lymphoma Is Characterized by Shifts in Relative Abundances of Specific Bacterial Taxa and Decreased Diversity in More Advanced Disease

Background Cutaneous T-cell lymphoma (CTCL) patients often suffer from recurrent skin infections and profound immune dysregulation in advanced disease. The gut microbiome has been recognized to influence cancers and cutaneous conditions; however, it has not yet been studied in CTCL.ObjectivesTo investigate the gut microbiome in patients with CTCL and in healthy controls.MethodsA case-control study was conducted between January 2019 and November 2020 at Northwestern’s busy multidisciplinary CTCL clinic (Chicago, Illinois, USA) utilizing 16S ribosomal RNA gene amplicon sequencing and bioinformatics analyses to characterize the microbiota present in fecal samples of CTCL patients (n = 38) and age-matched healthy controls (n = 13) from the same geographical region.ResultsGut microbial α-diversity trended lower in patients with CTCL and was significantly lower in patients with advanced CTCL relative to controls (P = 0.015). No differences in β-diversity were identified. Specific taxa were significantly reduced in patient samples; significance was determined using adjusted P-values (q-values) that accounted for a false discovery rate threshold of 0.05. Significantly reduced taxa in patient samples included the phylum Actinobacteria (q = 0.0002), classes Coriobacteriia (q = 0.002) and Actinobacteria (q = 0.03), order Coriobacteriales (q = 0.003), and genus Anaerotruncus (q = 0.01). The families Eggerthellaceae (q = 0.0007) and Lactobacillaceae (q = 0.02) were significantly reduced in patients with high skin disease burden.ConclusionsGut dysbiosis can be seen in patients with CTCL compared to healthy controls and is pronounced in more advanced CTCL. The taxonomic shifts associated with CTCL are similar to those previously reported in atopic dermatitis and opposite those of psoriasis, suggesting microbial parallels to the immune profile and skin barrier differences between these conditions. These findings may suggest new microbial disease biomarkers and reveal a new angle for intervention

Stability of RNA isolated from post-mortem tissues of Atlantic salmon (Salmo salar L.)

Studies of post-mortem interval on the stability of RNA from a number of various mammals have shown RNA to be stable for between 24 and 48 h following death. As yet there have been no studies looking at RNA stability in post-mortem tissues of poikilothermic fish. Brain, kidney, liver and muscle were collected from Atlantic salmon (Salmo salar) parr and samples of each tissue were placed into RNAlater (TM) after 0-24 h post-mortem storage at room temperature. Electrophoretic analysis of the total RNA showed degradation of ribosomal RNA only in muscle from 8 h onwards. Probing of northern blots with beta-actin showed that, in the brain, beta-actin mRNA was stable for 24 h post-mortem but degradation of mRNA was observed after 8 h with the kidney and liver and after 4 h with the muscle. Expression of the weakly expressed thyroid hormone receptor beta (TR beta) was detected by reverse transcriptase polymerase chain reaction (RT-PCR) in all tissues up to 24 h post-mortem although a reduction in PCR product was observed after 8 h with muscle and 24 h with kidney. Analysis with an Agilent 2100 Bioanalyzer showed that the RNA integrity number (RIN) of brain total RNA remained constant for 8 h post-mortem with only a small fall at 24 h post-mortem. The RINs of the remaining tissues indicated degradation at 8 h post-mortem with kidney and muscle and at 24 hours post-mortem with liver. Taken together these findings show that degradation of Atlantic salmon RNA is tissue dependent but stable for at least one hour post-mortem

Identification of a Kulshan caldera correlative tephra in the Palouse loess of Washington State, northwest USA

The Kulshan caldera formed at 3c1.15 Ma on the present-day site of Mt. Baker, Washington State, northwest USA and erupted a compositionally zoned (dacite-rhyolite) magma and a correlative eruptive, the Lake Tapps tephra. This tephra has previously been described, but only from the Puget Lowland of NW Washington. Here an occurrence of a Kulshan caldera correlative tephra is described from the Quaternary Palouse loess at the Washtucna site (WA-3). Site WA-3 is located in east-central Washington, 3c340 km southeast of the Kulshan caldera and 3c300 km east-southeast of the Lake Tapps occurrence in the Puget Lowland. Major- and trace element chemistry and location of the deposit at Washtucna within reversed polarity sediments indicates that it is not correlative with the Mesa Falls, Rockland, Bishop Ash, Lava Creek B or Huckleberry Ridge tephras. Instead the Washtucna deposit is related to the Lake Tapps tephra by fractional crystallisation, but is chemically distinct, a consequence of its eruption from a compositionally zoned magma chamber. The correlation of the Washtucna occurrence to the Kulshan caldera-forming eruption indicates that it had an eruptive volume exceeding 100 km3, and that its tephra could provide a valuable early-Pleistocene chronostratigraphic marker in the Pacific Northwest