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The productivity and climate feedbacks of tropical forests depend on tree physiological responses to warmer and, over large areas, seasonally drier conditions. However, knowledge regarding such responses is limited due to data scarcity. We studied the impact of growth temperature on net photosynthesis (An), maximum rates of Rubisco carboxylation at 25 °C (Vcmax25), stomatal conductance (gs) and the slope parameter of the stomatal conductance-photosynthesis model (g1), in 10 early successional (ES) and 8 late-successional (LS) tropical tree species grown at three sites along an elevation gradient in Rwanda, differing by 6.8 °C in daytime ambient air temperature. The effect of seasonal drought on An was also investigated. We found that warm climate decreased wet-season An in LS species, but not in ES species. Values of Vcmax25 were lower at the warmest site across both successional groups, and An and Vcmax25 were higher in ES compared with LS species. Stomatal conductance exhibited no significant site differences and g1 was similar across both sites and successional groups. Drought strongly reduced An at warmer sites but not at the coolest montane site and this response was similar in both ES and LS species. Our results suggest that warming has negative effects on leaf-level photosynthesis in LS species, while both LS and ES species suffer photosynthesis declines in a warmer climate with more pronounced droughts. The contrasting responses of An between successional groups may lead to shifts in species’ competitive balance in a warmer world, to the disadvantage of LS trees.

Background Many patients develop seroma after laparoscopic ventral hernia repair. It was hypothesized that leaving the hernial sac in situ may cause this complication. Methods In this patient‐ and outcome assessor‐blinded, parallel‐design single‐centre trial, patients undergoing laparoscopic intraperitoneal onlay mesh ventral hernia repair were randomized (1 : 1) to either conventional fascial closure or peritoneal bridging. The primary endpoint was the incidence of seroma 12 months after index surgery detected by CT, evaluated in an intention‐to‐treat analysis. Results Between September 2017 and May 2018, 62 patients were assessed for eligibility, of whom 25 were randomized to conventional closure and 25 to peritoneal bridging. At 3 months, one patient was lost to follow‐up in the conventional and peritoneal bridging groups respectively. No seroma was detected at 6 or 12 months in either group. The prevalence of clinical seroma was four of 25 (16 (95 per cent c.i. 2 to 30) per cent) versus none of 25 patients in the conventional fascial closure and peritoneal bridging groups respectively at 1 month after surgery (P = 0·110), and two of 24 (8 (0 to 19) per cent) versus none of 25 at 3 months (P = 0·235). There were no significant differences between the groups in other postoperative complications (one of 25 versus 0 of 25), rate of recurrent hernia within 1 year (none in either group) or postoperative pain. Conclusion Conventional fascial closure and peritoneal bridging did not differ with regard to seroma formation after laparoscopic ventral hernia repair. Trial registration: ClinicalTrials.gov (NCT03344575)., Fifty patients were enrolled and randomized to laparoscopic hernia repair with conventional fascial closure or a peritoneal bridging approach. Follow‐up by CT at 12 months (primary endpoint) revealed no seroma in either group, but seroma was detected clinically in the early postoperative period after 1 month (4 of 25 versus 0 of 25 patients in fascial closure and peritoneal bridging groups respectively) and 3 months (2 of 24 versus 0 of 25). The results suggest that peritoneal bridging is a safe and feasible alternative to conventional fascial closure, although larger studies are required to confirm this. No difference in seroma formation, complications or rate of recurrent hernia.

Background Little is known about the long-term side-effects of different treatments for hyperthyroidism. The few studies previously published on the subject either included only women or focused mainly on cancer outcomes. This register study compared the impact of surgery versus radioiodine on all-cause and cause-specific mortality in a cohort of men and women. Methods Healthcare registers were used to find hyperthyroid patients over 35 years of age who were treated with radioiodine or surgery between 1976 and 2000. Comparisons between treatments were made to assess all-cause and cause-specific deaths to 2013. Three different statistical methods were applied: Cox regression, propensity score matching and inverse probability weighting. Results Of the 10 992 patients included, 10 250 had been treated with radioiodine (mean age 65·1 years; 8668 women, 84·6 per cent) and 742 had been treated surgically (mean age 44·1 years; 633 women, 85·3 per cent). Mean duration of follow-up varied between 16·3 and 22·3 years, depending on the statistical method used. All-cause mortality was significantly lower among surgically treated patients, with a hazard ratio of 0·82 in the regression analysis, 0·80 in propensity score matching and 0·85 in inverse probability weighting. This was due mainly to lower cardiovascular mortality in the surgical group. Men in particular seemed to benefit from surgery compared with radioiodine treatment. Conclusion Compared with treatment with radioiodine, surgery for hyperthyroidism is associated with a lower risk of all-cause and cardiovascular mortality in the long term. This finding was more evident among men.

Stem CO2 efflux is known to vary seasonally and vertically along tree stems. However, annual tree- and stand-scale efflux estimates are commonly based on measurements made only a few times a year, during daytime and at breast height. In this study, the effect of these simplifying assumptions on annual efflux estimates and their influence on the estimates of the importance of stems in stand-scale carbon cycling are evaluated. In order to assess the strength of seasonal, diurnal and along-stem variability in CO2 efflux, half-hourly measurements were carried out at three heights on three mature Norway spruce (Picea abies (L.) Karst.) trees over a period of 3 years. Making the common assumption of breast height efflux rates being representative of the entire stem was found to result in underestimations of 10-17% in the annual tree-scale CO2 efflux. Upscaling using only daytime measurements from breast height increased the underestimation to 15-20%. Furthermore, the results show that the strength of the vertical gradient varies seasonally, being strongest in the early summer and non-existent during the cool months. The observed seasonality in the vertical CO2 efflux gradient could not be explained by variation in stem temperature, temperature response of the CO2 efflux (Q(10)), outer-bark permeability, CO2 transport in the xylem or CO2 release from the phloem. However, the estimated CO2 concentration immediately beneath the bark was considerably higher in the upper stem during the main period of diameter growth, coinciding with the strongest vertical efflux gradient. These results suggest that higher growth rates in the upper stem are the main cause for the observed vertical variation in the stem CO2 effluxes. Furthermore, the results indicate that accounting for the vertical efflux variation is essential for assessments of the importance of stems in stand-scale carbon cycling.

Photosynthesis is highly responsive to environmental and physiological variables, including phenology, foliage nitrogen (N) content, atmospheric CO2 concentration ([CO2]), irradiation (Q), air temperature (T) and vapour pressure deficit (D). Each of these responses is likely to be modified by long-term changes in climatic conditions such as rising air temperature and [CO2]. When modelling photosynthesis under climatic changes, which parameters are then most important to calibrate for future conditions? To assess this, we used measurements of shoot carbon assimilation rates and microclimate conditions collected at Flakaliden, northern Sweden. Twelve 40-year-old Norway spruce trees were enclosed in whole-tree chambers and exposed to elevated [CO2] and elevated air temperature, separately and in combination. The treatments imposed were elevated temperature, +2.8 °C in July/August and +5.6 °C in December above ambient, and [CO2] (ambient CO2 ∼370 μ mol mol(-1), elevated CO2 ∼700 μ mol mol(-1)). The relative importance of parameterization of Q, T and D responses for effects on the photosynthetic rate, expressed on a projected needle area, and the annual shoot carbon uptake was quantified using an empirical shoot photosynthesis model, which was developed and fitted to the measurements. The functional form of the response curves was established using an artificial neural network. The [CO2] treatment increased annual shoot carbon (C) uptake by 50%. Most important was effects on the light response curve, with a 67% increase in light-saturated photosynthetic rate, and a 52% increase in the initial slope of the light response curve. An interactive effect of light saturated photosynthetic rate was found with foliage N status, but no interactive effect for high temperature and high CO2. The air temperature treatment increased the annual shoot C uptake by 44%. The most important parameter was the seasonality, with an elongation of the growing season by almost 4 weeks. The temperature response curve was almost flat over much of the temperature range. A shift in temperature optimum had thus an insignificant effect on modelled annual shoot C uptake. The combined temperature and [CO2] treatment resulted in a 74% increase in annual shoot C uptake compared with ambient conditions, with no clear interactive effects on parameter values. (Less)

According to well-known biochemical and biophysical mechanisms, the stimulation of C(3) photosynthesis by elevated atmospheric CO(2) concentration ([CO(2)]) is strongly modified by changes in temperature and radiation. In order to investigate whether a static parameterization of the commonly used Farquhar et al. model of photosynthesis (i.e., without CO(2)-induced seasonal or thermal acclimation of photosynthetic capacity) can accurately predict these interactions in mature boreal Norway spruce (Picea abies (L.) Karst.) during the frost-free part of the growing season, shoot gas exchange was continuously measured on trees during their second/third year of exposure to ambient or doubled [CO(2)] inside whole-tree chambers. The relative CO(2)-induced enhancement of net photosynthesis (A(n)) at a given temperature remained stable over the study period, but increased strongly with temperature and radiation, in agreement with predictions by the model. Light-saturated A(n) (+67% at 20 °C), dark respiration (+36%) and intercellular to ambient [CO(2)] ratio (c(i)/c(a); +27%) were significantly increased by CO(2) treatment. Stomatal conductance (g(s)) was not significantly affected. Our results demonstrate that the Farquhar et al. model of photosynthesis has the capability to predict interactions between [CO(2)] and seasonal weather variability on A(n) in Norway spruce during the non-frost growing season without accounting for CO(2)-induced seasonal and/or thermal photosynthetic acclimation. However, stomatal model assumptions of reduced g(s) and constant c(i)/c(a) under rising atmospheric [CO(2)] did not hold.

A long-established theoretical result states that, for a given total canopy nitrogen (N) content, canopy photosynthesis is maximized when the within-canopy gradient in leaf N per unit area (N(a)) is equal to the light gradient. However, it is widely observed that N(a) declines less rapidly than light in real plant canopies. Here we show that this general observation can be explained by optimal leaf acclimation to light subject to a lower-bound constraint on the leaf mass per area (m(a)). Using a simple model of the carbon-nitrogen (C-N) balance of trees with a steady-state canopy, we implement this constraint within the framework of the MAXX optimization hypothesis that maximizes net canopy C export. Virtually all canopy traits predicted by MAXX (leaf N gradient, leaf N concentration, leaf photosynthetic capacity, canopy N content, leaf-area index) are in close agreement with the values observed in a mature stand of Norway spruce trees (Picea abies L. Karst.). An alternative upper-bound constraint on leaf photosynthetic capacity (A(sat)) does not reproduce the canopy traits of this stand. MAXX subject to a lower bound on m(a) is also qualitatively consistent with co-variations in leaf N gradient, m(a) and A(sat) observed across a range of temperate and tropical tree species. Our study highlights the key role of constraints in optimization models of plant function.

ObjectiveThyroid proteomics is a new direction in thyroid cancer research aiming at etiological understanding and biomarker identification for improved diagnosis.MethodsTwo-dimensional electrophoresis was applied to cytosolic protein extracts from frozen thyroid samples (ten follicular adenomas, nine follicular carcinomas, ten papillary carcinomas, and ten reference thyroids). Spots with differential expression were revealed by image and multivariate statistical analyses, and identified by mass spectrometry.ResultsA set of 25 protein spots significant for discriminating between the sample groups was identified. Proteins identified for nine of these spots were studied further including 14-3-3 protein beta/alpha, epsilon, and zeta/delta, peroxiredoxin 6, selenium-binding protein 1, protein disulfide-isomerase precursor, annexin A5 (ANXA5), tubulin alpha-1B chain, and α1-antitrypsin precursor. This subset of protein spots carried the same predictive power in differentiating between follicular carcinoma and adenoma or between follicular and papillary carcinoma, as compared with the larger set of 25 spots. Protein expression in the sample groups was demonstrated by western blot analyses. For ANXA5 and the 14-3-3 proteins, expression in tumor cell cytoplasm was demonstrated by immunohistochemistry both in the sample groups and an independent series of papillary thyroid carcinomas.ConclusionThe proteins identified confirm previous findings in thyroid proteomics, and suggest additional proteins as dysregulated in thyroid tumors.

IntroductionThe incidence of hyperthyroidism has been reported in various countries to be 23–93/100 000 inhabitants per year. This extended study has evaluated the incidence for ∼40% of the Swedish population of 9 million inhabitants. Sweden is considered to be iodine sufficient country.MethodsAll patients including children, who were newly diagnosed with overt hyperthyroidism in the years 2003–2005, were prospectively registered in a multicenter study. The inclusion criteria are as follows: clinical symptoms and/or signs of hyperthyroidism with plasma TSH concentration below 0.2 mIE/l and increased plasma levels of free/total triiodothyronine and/or free/total thyroxine. Patients with relapse of hyperthyroidism or thyroiditis were not included. The diagnosis of Graves' disease (GD), toxic multinodular goiter (TMNG) and solitary toxic adenoma (STA), smoking, initial treatment, occurrence of thyroid-associated eye symptoms/signs, and demographic data were registered.ResultsA total of 2916 patients were diagnosed withde novohyperthyroidism showing the total incidence of 27.6/100 000 inhabitants per year. The incidence of GD was 21.0/100 000 and toxic nodular goiter (TNG=STA+TMNG) occurred in 692 patients, corresponding to an annual incidence of 6.5/100 000. The incidence was higher in women compared with men (4.2:1). Seventy-five percent of the patients were diagnosed with GD, in whom thyroid-associated eye symptoms/signs occurred during diagnosis in every fifth patient. Geographical differences were observed.ConclusionThe incidence of hyperthyroidism in Sweden is in a lower range compared with international reports. Seventy-five percent of patients with hyperthyroidism had GD and 20% of them had thyroid-associated eye symptoms/signs during diagnosis. The observed geographical differences require further studies.

ObjectiveThe objective of this study was to investigate quality of life (QoL) in patients with Graves' disease treated with radioiodine or antithyroid drugs.Design and methodsThe design of the study consists of an open, prospective, randomized multicenter trial between radioiodine and medical treatment. A total of 308 patients were included in the study group: 145 patients in the medical group and 163 patients in the radioiodine group. QoL was measured with a 36-item Short Form Health Status Survey questionnaire (SF-36) at six time points during the 48-month study period.ResultsPatient who developed or got worse of thyroid-associated ophthalmopathy (TAO) at any time point during the 4-year study period (TAO group) had lower QoL when no respect was paid to the mode of treatment.TAO occurred in 75 patients who had radioiodine treatment at some time point during the study period as compared with TAO in 40 medically treated patients (PComparisons between the group of patients who have had TAO versus the group without TAO, in relation to treatments and time, showed significantly decreased QoL scores for the TAO groups at several time points during the study.In patients without TAO, there were no differences in QoL related to mode of treatment.ConclusionsThe QoL in patients with Graves' ophthalmopathy was similar in radioiodine and medically treated patients, but patients who developed or had worsening of TAO had decreased QoL independent of mode of treatment. Furthermore, patients with TAO recovered physically within 1 year but it took twice as long for them to recover mentally.

Objective: In a 14–21 year follow-up of health-related quality of life (HRQL) outcome of 179 patients after randomized treatment of Graves’ disease (GD) with surgical, medical or radioiodine, we found no differences. The HRQL for Graves’ patients, however, was lower compared with a large age- and sex-matched Swedish reference population. We have now studied whether the reported HRQL-scores by Medical Outcome Study 36-item Short-Form Health Status Survey (SF36) and quality of life 2004 (QoL2004) answers were related to the thyroid hormone state of the patient. Methods: This report comprises 91 of the original patients in which both the results of SF36 and QoL2004 questionnaire as well as serum thyroid hormones and current use of l-thyroxine treatment were available. Results: A large number of the patients had low or undetectable serum TSH concentrations. SF36 scores and answers to QoL2004 questionnaires were not correlated to TSH levels or associated with suppressed TSH. A low free triiodothyronine was weakly associated with a low GH score (P < 0.02) and elevated thyrotropin receptor antibody with a low physical component summary (P < 0.02). Conclusion: HRQL do not seem to be influenced by the thyroid hormone state of the patient including subclinical thyrotoxicosis. It is possible that the personality of GD patients as such may have resulted both in the development of GD and lower HQRL scores later on in life. Alternatively, the generic SF36 may not be a proper instrument to detect relevant differences in HRQL related to the thyroid state.

OBJECTIVE: Mutations in the RET proto-oncogene are found in about one third of sporadic medullary thyroid carcinomas (MTCs), mostly affecting codon 918. Glial cell line derived neurotropic factor (GDNF) and its membrane-bound GDNF family receptor alpha (GFRalpha-1), as well as neurturin (NTN) and its membrane-bound receptor GFRalpha-2 form a complex with the RET product, a receptor tyrosine kinase, resulting in downstream signaling to the nucleus. DESIGN: To elucidate the role of these RET ligands in MTC tumorigenesis, their expression was determined in 15 MTC samples, one papillary thyroid carcinoma (PTC) and three normal thyroid tissue specimens. METHODS: The mRNA expression of RET, GDNF, GFRalpha-1, NTN and GFRalpha-2 was investigated by mRNA in situ hybridization, and confirmed by reverse transcription-PCR analysis. RESULTS: None of the five genes was expressed in the normal thyroids or in the PTC. All MTCs showed expression of RET, 13 expressed GDNF, 12 expressed GFRalpha-1 and 9 expressed NTN and GFRalpha-2. In 7 of the tumors RET, GDNF and GFRalpha-1 were expressed at high levels, and in five of these seven tumors NTN and GFRalpha-2 genes were also expressed at high levels. The high level of expression was preferentially seen in tumor cells adjacent to stroma and connective tissue. All MTCs without expression of the RET ligands harbored the RET codon 918 mutation. CONCLUSIONS: The results suggest that this signaling pathway is important for MTC development, and that it may be activated by expression of the RET ligand complexes by the tumor cells themselves.