Integrating natural gradients, experiments, and statistical modeling in a distributed network experiment: An example from the WaRM Network.

A growing body of work examines the direct and indirect effects of climate change on ecosystems, typically by using manipulative experiments at a single site or performing meta-analyses across many independent experiments. However, results from single-site studies tend to have limited generality. Although meta-analytic approaches can help overcome this by exploring trends across sites, the inherent limitations in combining disparate datasets from independent approaches remain a major challenge. In this paper, we present a globally distributed experimental network that can be used to disentangle the direct and indirect effects of climate change. We discuss how natural gradients, experimental approaches, and statistical techniques can be combined to best inform predictions about responses to climate change, and we present a globally distributed experiment that utilizes natural environmental gradients to better understand long-term community and ecosystem responses to environmental change. The warming and (species) removal in mountains (WaRM) network employs experimental warming and plant species removals at high- and low-elevation sites in a factorial design to examine the combined and relative effects of climatic warming and the loss of dominant species on community structure and ecosystem function, both above- and belowground. The experimental design of the network allows for increasingly common statistical approaches to further elucidate the direct and indirect effects of warming. We argue that combining ecological observations and experiments along gradients is a powerful approach to make stronger predictions of how ecosystems will function in a warming world as species are lost, or gained, in local communities.

Effect of oral semaglutide on the pharmacokinetics of thyroxine after dosing of levothyroxine and the influence of co-administered tablets on the pharmacokinetics of oral semaglutide in healthy subjects: an open-label, one-sequence crossover, single-center, multiple-dose, two-part trial.

BACKGROUND: Oral semaglutide comprises the glucagon-like peptide-1 analog, semaglutide, and sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC). Levothyroxine has similar dosing conditions to oral semaglutide. This trial investigated if oral semaglutide co-administered with levothyroxine affects thyroxine (T4) exposure and if multiple placebo tablets co-administered with oral semaglutide affect semaglutide exposure. RESEARCH DESIGN AND METHODS: In this one-sequence crossover trial, 45 healthy subjects received levothyroxine (600 µg single-dose) alone, or with concomitant SNAC 300 mg or concomitant oral semaglutide 14 mg at steady-state. Subjects also received oral semaglutide 14 mg at steady-state alone or with five placebo tablets once-daily for 5 weeks. RESULTS: A 33% increase in total T4 exposure was observed with levothyroxine/oral semaglutide vs levothyroxine alone, but baseline-corrected maximum concentration (Cmax) was unaffected. SNAC alone did not affect total T4 exposure, whereas Cmax was slightly decreased. A 34% decrease in semaglutide exposure was observed when oral semaglutide was co-administered with placebo tablets, and Cmax also decreased. CONCLUSIONS: Levothyroxine pharmacokinetics were influenced by co-administration with oral semaglutide. Monitoring of thyroid parameters should be considered when treating patients with both oral semaglutide and levothyroxine. Oral semaglutide exposure was influenced by co-administration with multiple tablets, which is addressed in the dosing guidance.

Relationship Between Oral Semaglutide Tablet Erosion and Pharmacokinetics: A Pharmacoscintigraphic Study.

Semaglutide, a glucagon-like peptide-1 (GLP-1) analogue, has been coformulated in a tablet with the absorption enhancer, sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC). We investigated tablet erosion and the pharmacokinetics of oral semaglutide administered with 2 different water volumes and evaluated the relationships between these parameters. In a randomized, single-center (Quotient Sciences, UK), open-label, 2-period crossover trial, 26 healthy men received single doses of 10 mg oral semaglutide with 50 or 240 mL water while fasting. Tablet erosion and gastrointestinal transit were assessed by gamma scintigraphy. Semaglutide and SNAC plasma concentrations were measured until 24 and 6 hours, respectively, after administration. Complete tablet erosion (CTE) occurred in the stomach irrespective of water volume administered with the tablet (primary end point). Mean time to CTE was 85 versus 57 minutes with 50 versus 240 mL water (ratio 50/240 mL, 1.51; 95% confidence interval, 0.96-2.37; P = .072). Area under the semaglutide concentration-time curve from 0 to 24 hours (AUC0-24h,semaglutide ) and maximum semaglutide concentration (Cmax,semaglutide ) were ∼70% higher with 50 versus 240 mL water (P = .056 and P = .048, respectively). Median time to maximum semaglutide concentration (tmax,semaglutide ) was 1.5 hours independent of water volume with dosing. Higher AUC0-24h,semaglutide and Cmax,semaglutide and longer tmax,semaglutide were significantly correlated with longer time to CTE and later gastric emptying of tablet and water (all P < .05). The safety profile was as expected for the GLP-1 receptor agonist drug class. In conclusion, the oral semaglutide tablet erodes in the stomach irrespective of water volume with dosing. Slower tablet erosion in the stomach results in higher semaglutide plasma exposure.

An estimate of the effect of waiting time in the Danish asylum system on post-resettlement employment among refugees: Separating the pure delay effect from the effects of the conditions under which refugees are waiting.

We provide an estimate of the effect of refugees' length of waiting time in the Danish asylum system on their subsequent employment using administrative data. In contrast to previous studies, we take into account that refugees' labor market integration is delayed since their labor market access is restricted during the asylum-seeking phase. We find that an additional year of waiting time decreases subsequent employment by 3.2 percentage points on average. This effect is mostly driven by the delay in the labor market engagement among refugees. Waiting time may have an effect on subsequent employment that is additional to the delay effect, and this could be either positive or negative depending on the nature of the conditions under which asylum seekers live while waiting for their cases to be processed. We find that this additional effect is positive and statistically significant until observable individual characteristics are included, at which point it becomes small in magnitude and no longer significant.

Transcellular stomach absorption of a derivatized glucagon-like peptide-1 receptor agonist.

Oral administration of therapeutic peptides is hindered by poor absorption across the gastrointestinal barrier and extensive degradation by proteolytic enzymes. Here, we investigated the absorption of orally delivered semaglutide, a glucagon-like peptide-1 analog, coformulated with the absorption enhancer sodium N-[8-(2-hydroxybenzoyl) aminocaprylate] (SNAC) in a tablet. In contrast to intestinal absorption usually seen with small molecules, clinical and preclinical dog studies revealed that absorption of semaglutide takes place in the stomach, is confined to an area in close proximity to the tablet surface, and requires coformulation with SNAC. SNAC protects against enzymatic degradation via local buffering actions and only transiently enhances absorption. The mechanism of absorption is shown to be compound specific, transcellular, and without any evidence of effect on tight junctions. These data have implications for understanding how highly efficacious and specific therapeutic peptides could be transformed from injectable to tablet-based oral therapies.

Effect of Oral Semaglutide Compared With Placebo and Subcutaneous Semaglutide on Glycemic Control in Patients With Type 2 Diabetes: A Randomized Clinical Trial.

Importance: Glucagon-like peptide-1 (GLP-1) receptor agonists are effective therapies for the treatment of type 2 diabetes and are all currently available as an injection. Objectives: To compare the effects of oral semaglutide with placebo (primary) and open-label subcutaneous semaglutide (secondary) on glycemic control in patients with type 2 diabetes. Design, Setting, and Patients: Phase 2, randomized, parallel-group, dosage-finding, 26-week trial with 5-week follow-up at 100 sites (hospital clinics, general practices, and clinical research centers) in 14 countries conducted between December 2013 and December 2014. Of 1106 participants assessed, 632 with type 2 diabetes and insufficient glycemic control using diet and exercise alone or a stable dose of metformin were randomized. Randomization was stratified by metformin use. Interventions: Once-daily oral semaglutide of 2.5 mg (n = 70), 5 mg (n = 70), 10 mg (n = 70), 20 mg (n = 70), 40-mg 4-week dose escalation (standard escalation; n = 71), 40-mg 8-week dose escalation (slow escalation; n = 70), 40-mg 2-week dose escalation (fast escalation, n = 70), oral placebo (n = 71; double-blind) or once-weekly subcutaneous semaglutide of 1.0 mg (n = 70) for 26 weeks. Main Outcomes and Measures: The primary end point was change in hemoglobin A1c (HbA1c) from baseline to week 26. Secondary end points included change from baseline in body weight and adverse events. Results: Baseline characteristics were comparable across treatment groups. Of the 632 randomized patients (mean age, 57.1 years [SD, 10.6]; men, 395 (62.7%); diabetes duration, 6.3 years [SD, 5.2]; body weight, 92.3 kg [SD, 16.8]; BMI, 31.7 [SD, 4.3]), 583 (92%) completed the trial. Mean change in HbA1c level from baseline to week 26 decreased with oral semaglutide (dosage-dependent range, -0.7% to -1.9%) and subcutaneous semaglutide (-1.9%) and placebo (-0.3%); oral semaglutide reductions were significant vs placebo (dosage-dependent estimated treatment difference [ETD] range for oral semaglutide vs placebo, -0.4% to -1.6%; P = .01 for 2.5 mg, <.001 for all other dosages). Reductions in body weight were greater with oral semaglutide (dosage-dependent range, -2.1 kg to -6.9 kg) and subcutaneous semaglutide (-6.4 kg) vs placebo (-1.2 kg), and significant for oral semaglutide dosages of 10 mg or more vs placebo (dosage-dependent ETD range, -0.9 to -5.7 kg; P < .001). Adverse events were reported by 63% to 86% (371 of 490 patients) in the oral semaglutide groups, 81% (56 of 69 patients) in the subcutaneous semaglutide group, and 68% (48 of 71 patients) in the placebo group; mild to moderate gastrointestinal events were most common. Conclusions and Relevance: Among patients with type 2 diabetes, oral semaglutide resulted in better glycemic control than placebo over 26 weeks. These findings support phase 3 studies to assess longer-term and clinical outcomes, as well as safety. Trial Registration: clinicaltrials.gov Identifier: NCT01923181.

Labor market effects of intrauterine exposure to nutritional deficiency: Evidence from administrative data on Muslim immigrants in Denmark.

This paper examines whether nutritional disruptions experienced during the stage of fetal development impair an individual's labor market productivity later in life. We consider intrauterine exposure to the month of Ramadan as a natural experiment that might cause shocks to the inflow of nutrients essential for fetal development. Specifically, we use administrative data from Denmark to investigate the impact of exposure to Ramadan in utero on labor market outcomes of adult Muslim males, including employment status, annual salary, hourly wage rate, and hours of work. Our findings indicate that potential exposure to nutritional disruptions during a critical stage of fetal development is likely to have scarring effects on the fetus expressed as poor labor market outcomes later in life. Specifically, exposure to Ramadan around the 7th month of gestation results in a lower likelihood of employment and, to a lesser extent, a lower salary, and reduced labor supply. For example, the 7th month intrauterine exposure to Ramadan is associated with a 2.6 percentage points reduction in the likelihood of employment among Muslim males. We do not find an impact on the wage rate. Finally, we also document suggestive evidence that these results may partially be driven by increased disability and to a lesser extent by poor educational attainment among those who were exposed to Ramadan during this particular period in utero.

Phthalates Are Metabolised by Primary Thyroid Cell Cultures but Have Limited Influence on Selected Thyroid Cell Functions In Vitro.

Phthalates are plasticisers added to a wide variety of products, resulting in measurable exposure of humans. They are suspected to disrupt the thyroid axis as epidemiological studies suggest an influence on the peripheral thyroid hormone concentration. The mechanism is still unknown as only few in vitro studies within this area exist. The aim of the present study was to investigate the influence of three phthalate diesters (di-ethyl phthalate, di-n-butyl phthalate (DnBP), di-(2-ethylhexyl) phthalate (DEHP)) and two monoesters (mono-n-butyl phthalate and mono-(2-ethylhexyl) phthalate (MEHP)) on the differentiated function of primary human thyroid cell cultures. Also, the kinetics of phthalate metabolism were investigated. DEHP and its monoester, MEHP, both had an inhibitory influence on 3'-5'-cyclic adenosine monophosphate secretion from the cells, and MEHP also on thyroglobulin (Tg) secretion from the cells. Results of the lactate dehydrogenase-measurements indicated that the MEHP-mediated influence was caused by cell death. No influence on gene expression of thyroid specific genes (Tg, thyroid peroxidase, sodium iodine symporter and thyroid stimulating hormone receptor) by any of the investigated diesters could be demonstrated. All phthalate diesters were metabolised to the respective monoester, however with a fall in efficiency for high concentrations of the larger diesters DnBP and DEHP. In conclusion, human thyroid cells were able to metabolise phthalates but this phthalate-exposure did not appear to substantially influence selected functions of these cells.

Migration of phthalates on culture plates - an important challenge to consider for in vitro studies.

Phthalates are endocrine disruptors of the reproductive system and suspected to influence many other organ and hormone systems. They are also semi-volatile organic compounds present in the gas phase in the environment. Their mode of action has been investigated in numerous in vitro studies. Multi-well culture plates are typically used to study phthalates in cell cultures. In a pilot study, we observed evidence of phthalate migration in 24-well culture plates. As this has not previously been described, we investigated the phenomenon in more detail. Primary human thyroid epithelial cell cultures (n = 8 cultures) were exposed to either di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), mono-n-butyl phthalate (MnBP) or di-(2-ethylhexyl) phthalate (DEHP). Measurement of phthalate metabolites by mass spectrometry demonstrated that the short-branched DEP was able to migrate to adjacent wells when added to cell culture plates. DnBP also seemed to be able to migrate, unlike the long-branched DEHP or the monoester MnBP which did not seem to have this ability. High background levels of phthalate metabolites were also observed, which might compromise results from low dose phthalate studies. In conclusion, the migration of phthalates which is probably caused by their volatile properties might lead to false interpretation of study results.

Influence of phthalates on in vitro innate and adaptive immune responses.

Phthalates are a group of endocrine disrupting chemicals, suspected to influence the immune system. The aim of this study was to investigate the influence of phthalates on cytokine secretion from human peripheral blood mononuclear cells. Escherichia coli lipopolysaccharide and phytohemagglutinin-P were used for stimulation of monocytes/macrophages and T cells, respectively. Cells were exposed for 20 to 22 hours to either di-ethyl, di-n-butyl or mono-n-butyl phthalate at two different concentrations. Both diesters were metabolised to their respective monoester and influenced cytokine secretion from both monocytes/macrophages and T cells in a similar pattern: the secretion of interleukin (IL)-6, IL-10 and the chemokine CXCL8 by monocytes/macrophages was enhanced, while tumour necrosis factor (TNF)-α secretion by monocytes/macrophages was impaired, as was the secretion of IL-2 and IL-4, TNF-α and interferon-γ by T cells. The investigated phthalate monoester also influenced cytokine secretion from monocytes/macrophages similar to that of the diesters. In T cells, however, the effect of the monoester was different compared to the diesters. The influence of the phthalates on the cytokine secretion did not seem to be a result of cell death. Thus, results indicate that both human innate and adaptive immunity is influenced in vitro by phthalates, and that phthalates therefore may affect cell differentiation and regenerative and inflammatory processes in vivo.

Lymphadenectomy in surgical stage I epithelial ovarian cancer.

OBJECTIVE: To identify the extent of lymphadenectomy performed in women presenting with epithelial ovarian cancer macroscopically confined to the ovary. Furthermore, the effect of lymphadenectomy on overall survival is evaluated. DESIGN: A prospective nationwide case-only study. SETTING: Denmark 2005-2011. SAMPLE: All women registered in the nationwide Danish Gynecologic Cancer Database from 1 January 2005 to 1 May 2011, presenting with a tumor macroscopically confined to the ovary without visible evidence of abdominal spread at the time of the initial exploration (surgical stage I). METHOD: Descriptive and survival analyses of data from Danish Gynecologic Cancer Database. MAIN OUTCOME MEASURES: The annual proportion of women with surgical stage I disease who received lymphadenectomy and the survival in the two groups. RESULTS: Of 2361 women with epithelial ovarian cancer, 627 were identified with surgical stage I. Lymphadenectomy was performed in 216 women (34%) of whom 13 (6%) had lymph node metastases. At 5-year follow up 85% remained alive in the lymphadenectomy group compared with 80% in the control group (p = 0.064). The lymphadenectomy fraction increased from 24% in 2005 to 55% in 2011. When univariate and multivariate analyses were conducted only an insignificant difference in the survival probability was found between lymphadenectomy and no lymphadenectomy in women presenting with tumor macroscopically confined to the ovary. CONCLUSION: Although increasing, the number of women with surgical stage I disease in Denmark who receive lymphadenectomy remains low, but this did not seem to make a difference to survival.

Comorbidity is an independent prognostic factor for the survival of ovarian cancer: a Danish register-based cohort study from a clinical database.

OBJECTIVE: The aim of the study was to examine whether comorbidity is an independent prognostic factor for 3129 women diagnosed with ovarian cancer from 2005 to 2011. As Performance status (PS) might capture the impact of comorbidity we addressed whether comorbidity can be explained by PS or whether comorbidity has an independent impact on survival. METHODS: The Danish Gynecological Cancer Database (DGCD) is a national clinical database including information on comorbidity and a large number of tumor-related and patient-related factors. The Charlson Comorbidity Index was used to measure the patients' comorbidity based on the registration in DGCD. The overall mortality (OS) from the date of surgery to death or censoring was the outcome measure. RESULTS: The hazard ratio (HR) for patients with comorbidity was 3.31 (1.14-1.50) compared to patients without comorbidity after adjustment for age, stage, residual tumor, histology and grade. After including PS in the model, comorbidity remained significant for OS. Age, stage, residual tumor, histology and PS prove to be independent prognostic factors as well. No association is found between comorbidity and receiving surgery or not. CONCLUSION: Comorbidity is an independent prognostic factor, and has a negative impact on the survival of ovarian cancer patients. However, comorbidity has a smaller impact on survival compared with the other prognostic factors considered.

Do Thyroid Disrupting Chemicals Influence Foetal Development during Pregnancy?

Maternal euthyroidism during pregnancy is crucial for normal development and, in particular, neurodevelopment of the foetus. Up to 3.5 percent of pregnant women suffer from hypothyroidism. Industrial use of various chemicals-endocrine disrupting chemicals (EDCs)-has been shown to cause almost constant exposure of humans with possible harmful influence on health and hormone regulation. EDCs may affect thyroid hormone homeostasis by different mechanisms, and though the effect of each chemical seems scarce, the added effects may cause inappropriate consequences on, for example, foetal neurodevelopment. This paper focuses on thyroid hormone influence on foetal development in relation to the chemicals suspected of thyroid disrupting properties with possible interactions with maternal thyroid homeostasis. Knowledge of the effects is expected to impact the general debate on the use of these chemicals. However, more studies are needed to elucidate the issue, since human studies are scarce.

Interleukin-8 production from human somatotroph adenoma cells is stimulated by interleukin-1ß and inhibited by growth hormone releasing hormone and somatostatin.

OBJECTIVE: Pituitary adenomas cause morbidity and mortality due to their localization and influence on pituitary hormone secretion. Although the pathogenesis of pituitary adenomas is unclear, studies have indicated that cytokines are involved. We investigated the role of cytokines, in particular interleukin (IL)-8, in the pathogenesis of growth hormone (GH) producing tumours. DESIGN: Human somatotroph adenoma tissue was obtained from patients undergoing surgery for acromegaly. The tissue underwent mechanical and enzymatic digestion, was washed, suspended and cultured in 24-chamber plates. After stimulation/inhibition supernatants were harvested. As control of growth hormone producing properties of the cultured cells, GH releasing hormone (GHRH) stimulated and somatostatin inhibited the GH response. RESULTS: The cultured adenoma cells released both IL-6 and IL-8 and the secretion was inhibited by GHRH and somatostatin. IL-1ß dose-dependently stimulated GH, IL-6 and IL-8 secretion. CONCLUSION: Using cultured primary somatotroph adenoma cells as a dynamic method, we found a consistent release not only of IL-6 as described previously, but also of IL-8. This finding could be important for reassessing a role of these cytokines in the pathogenesis of pituitary tumour growth and function, and thus form a basis for targeted therapy. In line with previous studies, our results further indicated a common physiological or pathophysiological reaction of endocrine cells to cytokine stimulation.

Iodine and tri-iodo-thyronine reduce the incidence of type 1 diabetes mellitus in the autoimmune prone BB rats.

Thyroid hormones modulate the immune system and metabolism, influence insulin secretion, and cause decreased glucose tolerance. Thyroid hormones have been described to change the incidence of spontaneous autoimmune thyroiditis in Bio-Breeding/Worcester (BB) rats but it is unknown how these hormones affect the development of type 1 diabetes mellitus (T1DM). The aim was to investigate the influence of changes in thyroid function during postnatal development on the prevalence of T1DM in BB rats and the influence of T3 on the beta cell mass in non-diabetic Wistar rats. BB rats were treated with sodium iodine (NaI) or thyroid stimulating hormone (TSH) neonatally or with tri-iodo-thyronine (T3) during adolescence. At the age of 19 weeks the incidence of T1DM and the degree of insulitis were evaluated. The influence of T3 treatment on the beta cell mass was evaluated in Wistar rats by unbiased stereological methods. The incidence of T1DM in control BB rats was 68% at the age of 19 weeks. NaI and T3 reduced the incidence, whereas TSH had no effect. In Wistar rats T3 treatment increased the beta cell mass per bodyweight. The modulation of thyroid function during postnatal development may thus affect the precipitation of T1DM in genetically susceptible individuals.

Unsuccessful radioiodine treatment of a non-toxic goiter: a case report.

A middle-aged woman with a large right-sided, non-toxic goiter with low iodine uptake was admitted to the Department of Endocrinology with the purpose of volume reduction of the goiter. Thyroid pertechnetate scintigraphy showed homogenous and diffuse uptake in both lobes. Initially thyroxine treatment was given without volume-reducing effect. Radioiodine was administered twice to deliver a total radiation dose of 70 mCi iodine (I)-131. Subsequent pertechnetate scintigraphy showed that the normal-sized, normally functioning left lobe had disappeared after radioiodine, whereas the enlarged right lobe appeared unchanged. During the following years the size of the right lobe increased, and compression symptoms developed. The thyroid gland finally had to be removed by surgery. A large solitary thyroid nodule was removed, but no left lobe was identified. After surgery the patient had no thyroid tissue and had to be substituted by thyroid hormones. Despite good results of iodine treatment of non-toxic goiters, this case describes an unintended outcome leaving a patient without thyroid tissue, and a protracted course could have been avoided if the patient had undergone surgery earlier. However, this reported case should not discredit the use of radioiodine treatment of non-toxic goiters, but focus on patients with a single large solitary adenoma in whom this treatment may be inappropriate.

Thyrotropin-releasing hormone stimulation test in patients with pituitary pathology.

OBJECTIVES: To evaluate the value of the thyrotropin-releasing hormone (TRH) stimulation test in the diagnostic work-up of the thyroid function in patients with pituitary pathology. METHODS: To compare the thyrotropin (TSH) response and the absolute and fold changes after TRH administration in 35 patients with pituitary pathology and 26 normal subjects. RESULTS: Nine of the patients and 2 of the normal subjects had a pathological response. No difference in the thyrotropic response to TRH was found either for the actual values, or for the absolute or fold changes of TSH between the groups. CONCLUSION: The role of the TRH test in the evaluation of thyroid function in patients with pituitary pathology is modest. The best variables for evaluation of the presence of central hypothyroidism are still a free thyroxine estimate combined with an inappropriately low TSH.