Effects of rare kidney diseases on kidney failure: a longitudinal analysis of the UK National Registry of Rare Kidney Diseases (RaDaR) cohort

Background Individuals with rare kidney diseases account for 5–10% of people with chronic kidney disease, but constitute more than 25% of patients receiving kidney replacement therapy. The National Registry of Rare Kidney Diseases (RaDaR) gathers longitudinal data from patients with these conditions, which we used to study disease progression and outcomes of death and kidney failure. Methods People aged 0–96 years living with 28 types of rare kidney diseases were recruited from 108 UK renal care facilities. The primary outcomes were cumulative incidence of mortality and kidney failure in individuals with rare kidney diseases, which were calculated and compared with that of unselected patients with chronic kidney disease. Cumulative incidence and Kaplan–Meier survival estimates were calculated for the following outcomes: median age at kidney failure; median age at death; time from start of dialysis to death; and time from diagnosis to estimated glomerular filtration rate (eGFR) thresholds, allowing calculation of time from last eGFR of 75 mL/min per 1·73 m2 or more to first eGFR of less than 30 mL/min per 1·73 m2 (the therapeutic trial window). Findings Between Jan 18, 2010, and July 25, 2022, 27 285 participants were recruited to RaDaR. Median follow-up time from diagnosis was 9·6 years (IQR 5·9–16·7). RaDaR participants had significantly higher 5-year cumulative incidence of kidney failure than 2·81 million UK patients with all-cause chronic kidney disease (28% vs 1%; p<0·0001), but better survival rates (standardised mortality ratio 0·42 [95% CI 0·32–0·52]; p<0·0001). Median age at kidney failure, median age at death, time from start of dialysis to death, time from diagnosis to eGFR thresholds, and therapeutic trial window all varied substantially between rare diseases. Interpretation Patients with rare kidney diseases differ from the general population of individuals with chronic kidney disease: they have higher 5-year rates of kidney failure but higher survival than other patients with chronic kidney disease stages 3–5, and so are over-represented in the cohort of patients requiring kidney replacement therapy. Addressing unmet therapeutic need for patients with rare kidney diseases could have a large beneficial effect on long-term kidney replacement therapy demand. Funding RaDaR is funded by the Medical Research Council, Kidney Research UK, Kidney Care UK, and the Polycystic Kidney Disease Charity

Lack of Effect of Steroids on Thyrotropin-Releasing Hormone (TRH) Mediated Thyrotropin (TSH) Release in Man

Plasma thyrotropin levels were measured after the acute i.v. administration of 400 µg of synthetic thyrotropin-releasing hormone (TRH) in 6 patients with Addison’s disease, 2 patients with thrombo-cytopenia, and 3 postmenopausal women before and after treatment with cortisone acetate (37.5 mg/day), prednisone (150 mg/day) and diethylstilbesterol (15.0 mg), respectively. All had normal thyroid function with the exception of one hypothyroid postmenopausal woman. There was no significant difference between the responses to TRH before and after steroids, nor between either response and the TSH release found in a group of 20 healthy male volunteers, except for the hypothyroid woman who had a supranormal response and the thrombocytopenic patients whose responses were blunted. In addition, 5 normal volunteers received 100 µg TRH i.v. 1 h after the acute i.v. administration of 30.0 mg methyl prednisolone, 3.0 mg ethinyl estradiol, or saline. There was no significant change in the basal TSH concentration during the 1-hour interval prior to TRH treatment, and the TSH response to TRH after the administration of either steroid was not significantly different from that after the saline control. It is concluded that neither acute pharmacologic treatment nor chronic replacement therapy with either estrogens or corticosteroids affects the TSH response of the pituitary to TRH in man. However, chronic pharmacologic treatment with glucocortico-steroids may have a suppressive effect

Evidence for an apartheid-like social structure in early Anglo-Saxon England

The role of migration in the Anglo-Saxon transition in England remains controversial. Archaeological and historical evidence is inconclusive, but current estimates of the contribution of migrants to the English population range from less than 10 000 to as many as 200 000. In contrast, recent studies based on Y-chromosome variation posit a considerably higher contribution to the modern English gene pool (50-100%). Historical evidence suggests that following the Anglo-Saxon transition, people of indigenous ethnicity were at an economic and legal disadvantage compared to those having Anglo-Saxon ethnicity. It is likely that such a disadvantage would lead to differential reproductive success. We examine the effect of differential reproductive success, coupled with limited intermarriage between distinct ethnic groups, on the spread of genetic variants. Computer simulations indicate that a social structure limiting intermarriage between indigenous Britons and an initially small Anglo-Saxon immigrant population provide a plausible explanation of the high degree of Continental male-line ancestry in England

Modelling of bubble-mediated gas transfer : fundamental principles and a laboratory test

gas transfer; wave breaking, air-sea interaction; sea surfaceInternational audienceThe air–water exchange of gases can be substantially enhanced by wave breaking and specifically by bubble-mediated transfer. A feature of bubble-mediated transfer is the additional pressure on bubbles resulting from the hydrostatic forces on a submerged bubble and from surface tension and curvature. This peculiarity results in asymmetry of bubble-mediated gas transfer and equilibrium supersaturations of dissolved gases in a bubbly ocean. A second peculiarity is the finite capacity of bubbles, so that the composition of a bubble may change during the exchange. The result is that gas transfer mediated by bubbles is characterized by an altered dependence on the molecular properties of the dissolved gas compared to direct transfer across the main air–water interface. A related phenomenon for bubble plumes with a high void fraction (air volume to total volume ratio) is that the composition of the dissolved gas within the interstitial water of a plume may alter during the exchange process and only mix into the full water reservoir later. Three asymptotes are identified for gas exchange mediated by high-void-fraction bubble plumes and a semi-empirical parameterization of bubble-mediated gas transfer is devised on the basis of these asymptotes, which describes the dependence of the overall transfer velocity on plume properties and molecular properties of the gas. These models are confronted with data from laboratory experiments. The experiments use artificial aeration with the gas source switched during each run. Measurements of the bubble distribution enable calculation of the theoretical transfer of the gases. A parameterization fits the theoretical transfer satisfactorily. Gas measurements are used to test if the actual transfer of gases is similar to the theoretical transfer. The experimental method enables separation of bubble-mediated transfer from transfer directly across the main air–water interface. The agreement between gas and bubble-derived values of transfer velocity is sufficient to generally validate the theory, but is imprecise. The results suggest that the interstitial water plays a significant role in limiting gas transfer–in particular, limiting transfer of helium–despite the fact that typical void fractions were low (< 0.1%). It should be possible to predict gas transfer velocities in the field by simulating oceanic bubble plumes sufficient to constrain that part of the transfer, but targets of 10% or 20% may be beyond reach especially for the most poorly soluble gases (for which the bubble-mediated mechanism is particularly important). These simulations require accurate bubble distributions, void fractions and a good description of the entire plume dynamics. Such simulations are particularly important for interpreting dual tracer and nitrogen/oxygen experiments in stormy conditions, where the relative transfer of different gases is a non-trivial problem