Insights from the first global population estimate of Weddell seals in Antarctica

The Weddell seal is one of the best-studied marine mammals in the world, owing to a multidecadal demographic effort in the southernmost part of its range. Despite their occurrence around the Antarctic coastline, we know little about larger scale patterns in distribution, population size, or structure. We combined high-resolution satellite imagery from 2011, crowd-sourcing, and habitat modeling to report the first global population estimate for the species and environmental factors that influence its distribution. We estimated ~202,000 (95% confidence interval: 85,345 to 523,140) sub-adult and adult female seals, with proximate ocean depth and fast-ice variables as factors explaining spatial prevalence. Distances to penguin colonies were associated with seal presence, but only emperor penguin population size had a strong negative relationship. The small, estimated population size relative to previous estimates and the seals' nexus with trophic competitors indicates that a community ecology approach is required in efforts to monitor the Southern Ocean ecosystem

Mean sojourn time, overdiagnosis, and reduction in advanced stage prostate cancer due to screening with PSA: implications of sojourn time on screening

This study aimed to assess the mean sojourn time (MST) of prostate cancer, to estimate the probability of overdiagnosis, and to predict the potential reduction in advanced stage disease due to screening with PSA. The MST of prostate cancer was derived from detection rates at PSA prevalence testing in 43 842 men, aged 50–69 years, as part of the ProtecT study, from the incidence of non-screen-detected cases obtained from the English population-based cancer registry database, and from PSA sensitivity obtained from the medical literature. The relative reduction in advanced stage disease was derived from the expected and observed incidences of advanced stage prostate cancer. The age-specific MST for men aged 50–59 and 60–69 years were 11.3 and 12.6 years, respectively. Overdiagnosis estimates increased with age; 10–31% of the PSA-detected cases were estimated to be overdiagnosed. An interscreening interval of 2 years was predicted to result in 37 and 63% reduction in advanced stage disease in men 65–69 and 50–54 years, respectively. If the overdiagnosed cases were excluded, the estimated reductions were 9 and 54%, respectively. Thus, the benefit of screening in reducing advanced stage disease is limited by overdiagnosis, which is greater in older men

Influence of omega-6 PUFA arachidonic acid and bone marrow adipocytes on metastatic spread from prostate cancer

Background: Prostate cancer (CaP) preferentially metastasises to the bone, and we have previously shown that the poly-unsaturated fatty acid (PUFA) arachidonic acid (AA) is a potent stimulator of CaP invasion. Here we present that AA promotes CaP invasion by inducing bone marrow adipocyte formation. Methods: Boyden invasion-chamber assays assessed the ability of dietary oils, their PUFA components, and specific PUFA-loaded adipocytes to induce PC-3 invasion. Lipid transfer and metabolism was followed using deuterated AA and Fourier Transform Infrared spectroscopy (FTIR). Results: Poly-unsaturated fatty acid constituents, but not their corresponding dietary oils, induced PC-3 invasion. PUFAs induce bone marrow adipocyte (BM-Ad) differentiation with AA inducing higher levels of BM-Ad differentiation, as compared with other PUFAs (3998514.4 vs 932265.8; P0.00002), which stimulated greater PC-3 invasion than free AA (22 408.5607.4 vs 16 236313.9; P0.01111) or adipocytes generated in the presence of other PUFAs. In bone marrow co-culture PC-3 and BM-Ad interactions result in direct uptake and metabolism of AA by PC-3 cells, destruction of the adipocyte and subsequent formation of a bone metastasis. Conclusion: The data supports the hypothesis that AA not only promotes CaP invasion, it also prepares the soil, making it more supportive for implantation and propagation of the migrating metastatic cell. © 2010 Cancer Research UK. All rights reserved

Risk of urogenital infections in non-diabetic patients treated with sodium glucose transporter 2 (SGLT2) inhibitors. Systematic review and meta-analysis

Although SGLT2 inhibitors have been initially employed in the treatment of type 2 diabetes, their clinical use was later extended to the treatment of other conditions such as heart failure, chronic kidney disease and obesity. In patients with type 2 diabetes, the administration of SGLT2 inhibitors has been associated with an increased incidence of urogenital infections, which may be linked to high glucose levels in the urine. The rate of urogenital side effects may be different in non-diabetic patients. The aim of this study was to review the risk of urogenital infections in non-diabetic patients taking SGLT2 inhibitors. Materials and methods: We conducted a systematic review and meta-analysis by searching PubMed and EMBASE for randomized controlled trials (RCTs) reporting urogenital adverse effects in non-diabetic patients treated with SGLT2 inhibitors. Odds ratios for urogenital infections were calculated using random effect Mantel-Haenszel statistics. Results: Out of 387 citations retrieved, 12 eligible RCTs were assessed for risk of bias and included in the meta-analysis. Compared to placebo, SGLT2 inhibitors were associated with increased odds of genital infections (OR 3.01, 95% CI: 1.93- 4.68, 9 series, 7326 participants, Z = 5.74, p < 0.0001, I2 = 0%) as well as urinary tract infections (OR 1.33, 95% CI: 1.13-1.57, 9 series, 7326 participants, Z = 4.05, p < 0.0001, I2 = 0%). When four trials investigating the effects of SGLT2 inhibitors in populations including both diabetic and non-diabetic patients were considered, administration of SGLT2 inhibitors in diabetic patients was associated with significantly higher odds of genital infections but not urinary tract infections compared to patients without type 2 diabetes. In patients taking placebo, the odds for urinary tract infections were significantly increased in diabetic patients compared to non-diabetic patients. Conclusions: The risk of genital infections is increased also in non-diabetic patients taking SGLT2 inhibitors although at a lesser extent that in diabetics. A careful assessment of the local anatomical conditions and of the history of previous urogenital infections is desirable to select those patients who need more intense follow-up, possibly combined with prophylactic measures of infections during treatment with SGLT2 inhibitors

The development of a web- and a print-based decision aid for prostate cancer screening

Background Whether early detection and treatment of prostate cancer (PCa) will reduce disease-related mortality remains uncertain. As a result, tools are needed to facilitate informed decision making. While there have been several decision aids (DAs) developed and tested, very few have included an exercise to help men clarify their values and preferences about PCa screening. Further, only one DA has utilized an interactive web-based format, which allows for an expansion and customization of the material. We describe the development of two DAs, a booklet and an interactive website, each with a values clarification component and designed for use in diverse settings. Methods We conducted two feasibility studies to assess men\u27s (45-70 years) Internet access and their willingness to use a web- vs. a print-based tool. The booklet was adapted from two previous versions evaluated in randomized controlled trials (RCTs) and the website was created to closely match the content of the revised booklet. Usability testing was conducted to obtain feedback regarding draft versions of the materials. The tools were also reviewed by a plain language expert and the interdisciplinary research team. Feedback on the content and presentation led to iterative modifications of the tools. Results The feasibility studies confirmed that the Internet was a viable medium, as the majority of men used a computer, had access to the Internet, and Internet use increased over time. Feedback from the usability testing on the length, presentation, and content of the materials was incorporated into the final versions of the booklet and website. Both the feasibility studies and the usability testing highlighted the need to address men\u27s informed decision making regarding screening. Conclusions Informed decision making for PCa screening is crucial at present and may be important for some time, particularly if a definitive recommendation either for or against screening does not emerge from ongoing prostate cancer screening trials. We have detailed our efforts at developing print- and web-based DAs to assist men in determining how to best meet their PCa screening preferences. Following completion of our ongoing RCT designed to test these materials, our goal will be to develop a dissemination project for the more effective tool

Predictive equation derived from 6,497 doubly labelled water measurements enables the detection of erroneous self-reported energy intake

Nutritional epidemiology aims to link dietary exposures to chronic disease, but the instruments for evaluating dietary intake are inaccurate. One way to identify unreliable data and the sources of errors is to compare estimated intakes with the total energy expenditure (TEE). In this study, we used the International Atomic Energy Agency Doubly Labeled Water Database to derive a predictive equation for TEE using 6,497 measures of TEE in individuals aged 4 to 96 years. The resultant regression equation predicts expected TEE from easily acquired variables, such as body weight, age and sex, with 95% predictive limits that can be used to screen for misreporting by participants in dietary studies. We applied the equation to two large datasets (National Diet and Nutrition Survey and National Health and Nutrition Examination Survey) and found that the level of misreporting was >50%. The macronutrient composition from dietary reports in these studies was systematically biased as the level of misreporting increased, leading to potentially spurious associations between diet components and body mass index

Author Correction: Predictive equation derived from 6,497 doubly labelled water measurements enables the detection of erroneous self-reported energy intake

Correction to: Nature Food https://doi.org/10.1038/s43016-024-01089-5, published online 13 January 2025. In the version of this article initially published, there was an error in the application of the equation used to predict the total energy expenditure of individuals in the NDNS and NHANES surveys. The output of the equation is in MJ, the two survey intake estimates are in kJ, and while the predicted values were converted to kJ, the value for total energy expenditure, using kJ, was mistakenly inserted into the equations used to derive the extent of over- and underreporting, resulting in an overestimation of underreporting. For instance, the original abstract reported that the level of misreporting was >50%, whereas it is now determined to be 27.4%. The corrected calculations led to revisions throughout the text, Tables 2–4, Figs. 2 and 3, and the Supplementary Information. Other minor errors were also corrected in this new version. For transparent comparison, the original, uncorrected article is available alongside this amendment. The changes have been made in the HTML and PDF versions of the article. The authors sincerely apologise for these errors and any inconvenience caused. Please direct any correspondence to John R. Speakman

Predictive equation derived from 6,497 doubly labelled water measurements enables the detection of erroneous self-reported energy intake

Nutritional epidemiology aims to link dietary exposures to chronic disease, but the instruments for evaluating dietary intake are inaccurate. One way to identify unreliable data and the sources of errors is to compare estimated intakes with the total energy expenditure (TEE). In this study, we used the International Atomic Energy Agency Doubly Labeled Water Database to derive a predictive equation for TEE using 6,497 measures of TEE in individuals aged 4 to 96 years. The resultant regression equation predicts expected TEE from easily acquired variables, such as body weight, age and sex, with 95% predictive limits that can be used to screen for misreporting by participants in dietary studies. We applied the equation to two large datasets (National Diet and Nutrition Survey and National Health and Nutrition Examination Survey) and found that the level of misreporting was >50%. The macronutrient composition from dietary reports in these studies was systematically biased as the level of misreporting increased, leading to potentially spurious associations between diet components and body mass index