For many species, the population-mean body size increases with latitude. Although heat conservation and starvation resistance are frequently invoked to explain latitudinal clines, these explanations seem incompatible with the natural history of turtles, which also increase in size with latitude. We collate the population-mean body size for nearly 100 populations of North American freshwater turtles belonging to seven species. We test the hypothesis that temperature-size relationships in turtles are driven by strong seasonality in the north, which leads to maturation at a larger size and the production of relatively fewer, larger clutches per season. Our results, however, do not support the seasonality hypothesis. We present two new hypotheses that can explain the generality of temperature-size responses in chelonians. First, oxygen consumption is temperature sensitive, placing a premium on small size in warm aquatic environments, because smaller size reduces total oxygen demand during activities requiring submergence. Second, overwintering physiology of turtles might drive size clines, because a decrease in mass-specific metabolic rate with size might result in a disproportionate increase in the capacity of large individuals to buffer lactic acid in anoxic conditions. The pursuit of a general explanation for temperature-size relationships in chelonians would benefit from comparing temperature-size responses between aquatic and terrestrial species.
ObjectiveNew-onset immune-mediated inflammatory diseases (IMIDs) and flares of pre-existing IMIDs have been reported following anti- SARS-CoV2 vaccination. Our study aimed at describing a retrospective cohort of patients developing new-onset IMIDs or flares of known IMIDs within 30 days after any anti-SARS-CoV2 vaccine dose.MethodsWe evaluated clinical records of all inpatients and outpatients referring to our institution between February 2021 and February 2022 with any clinical manifestations. We then selected those having received any anti-SARS-CoV2 vaccine dose within the prior 30 days and classified them as having or not a previous IMID according to predefined criteria. We recorded new-onset IMIDs or flares of known IMIDs and investigated any relationship with demographic, clinical and serological variables.Results153 patients that received any anti-SARS-CoV2 vaccine dose within the previous 30 days were included of which 45 (29%) already had a diagnosis of IMID while 108 (71%) had no previously diagnosed IMID. 33 (30%) of the 108 patients, were diagnosed with a new-onset IMID. Pericarditis, polymyalgia rheumatica and vasculitis were the most frequent conditions. Among the 45 patients that already had an IMID, disease flare was the reason for referral in 69% of patients. Patients with an IMID flare had a lower number of comorbidities and tended to be younger compared with those who developed other conditions after anti-SARS-CoV2 vaccination.ConclusionWe provided a retrospective overview of a cohort of patients who developed new-onset IMIDs or flares of known IMIDs within 30 days after any dose of anti-SARS-CoV2 vaccine. While vaccination campaigns proceed, postvaccination surveillance programmes are ongoing and hopefully will soon clarify whether a causal relationship between vaccines and new-onset/flares of IMIDs exists.
Rationale It remains unclear how gastroesophageal reflux disease (GERD) affects allograft microbial community composition in lung transplant recipients and its impact on lung allograft inflammation and function. Objectives Our objective was to compare the allograft microbiota in lung transplant recipients with or without clinically diagnosed GERD in the first year after transplant and assess associations between GERD, allograft microbiota, inflammation, and acute and chronic lung allograft dysfunction (ALAD and CLAD). Methods A total of 268 BAL samples were collected from 75 lung transplant recipients at a single transplant center every 3 months after transplant for 1 year. Ten transplant recipients from a separate transplant center provided samples before and after antireflux Nissen fundoplication surgery. Microbial community composition and density were measured using 16S ribosomal RNA gene sequencing and quantitative polymerase chain reaction, respectively, and inflammatory markers and bile acids were quantified. Measurements and Main Results We observed a range of allograft community composition with three discernible types (labeled community state types [CSTs] 1–3). Transplant recipients with GERD were more likely to have CST1, characterized by high bacterial density and relative abundance of the oropharyngeal colonizing genera Prevotella and Veillonella . GERD was associated with more frequent transitions to CST1. CST1 was associated with lower inflammatory cytokine concentrations than pathogen-dominated CST3 across the range of microbial densities observed. Cox proportional hazard models revealed associations between CST3 and the development of ALAD/CLAD. Nissen fundoplication decreased bacterial load and proinflammatory cytokines. Conclusions GERD was associated with a high bacterial density, Prevotella- and Veillonella- dominated CST1. CST3, but not CST1 or GERD, was associated with inflammation and early development of ALAD and CLAD. Nissen fundoplication was associated with a reduction in microbial density in BAL fluid samples, especially the CST1-specific genus, Prevotella .
Rationale: Gastroesophageal reflux disease (GERD) may affect lung allograft inflammation and function through its effects on allograft microbial community composition in lung transplant recipients. Objectives: Our objective was to compare the allograft microbiota in lung transplant recipients with or without clinically diagnosed GERD in the first post-transplant year, and assess associations between GERD, allograft microbiota, inflammation and acute and chronic lung allograft dysfunction (ALAD/CLAD). Methods: 268 bronchoalveolar lavage samples were collected from 75 lung transplant recipients at a single transplant centre every 3 months post-transplant for 1 year. Ten transplant recipients from a separate transplant centre provided samples pre/post-anti-reflux Nissen fundoplication surgery. Microbial community composition and density were measured using 16S rRNA gene sequencing and qPCR, respectively and inflammatory markers and bile acids were quantified. Measurements and Main Results: We observed three community composition profiles (labelled community state types, CSTs 1-3). Transplant recipients with GERD were more likely to have CST1, characterized by high bacterial density and relative abundance of the oropharyngeal colonizing genera Prevotella and Veillonella. GERD was associated with more frequent transition to CST1. CST1 was associated with lower per-bacteria inflammatory cytokine levels than the pathogen-dominated CST3. Time-dependant models revealed associations between CST3 and development of ALAD/CLAD. Nissen fundoplication decreased bacterial load and pro-inflammatory cytokines. Conclusion: GERD was associated with a high bacterial density, Prevotella/Veillonella dominated CST1. CST3, but not CST1 or GERD, was associated with inflammation and early development of ALAD/CLAD. Nissen fundoplication was associated with decreases in microbial density in BALF samples, especially the CST1-specific genus, Prevotella.
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