Isoprene Emission and Carbon Dioxide Protect Aspen Leaves from Heat Stress

High temperature, especially above 35oC, is known to reduce leaf photosynthetic rate in many tree species. This study investigated the effect of high temperature on isoprene-emitting (aspen) and non- emitting (birch) trees under ambient and elevated CO2 under open field conditions. Aspen trees tolerate heat better than birch trees and elevated CO2 protects both species against moderate heat stress. The increased thermotolerance in aspen trees compared to the birch trees may result from the aspen's ability to produce isoprene. Elevated CO2 increased carboxylation capacity, photosynthetic electron transport capacity and triose phosphate use in both birch and aspen trees. High temperature decreased all of these parameters in birch regardless of CO2 treatment but only photosynthetic electron transport and triose phosphate use at ambient CO2 were reduced in aspen. As temperature rises, non-isoprene-emitting trees will be at a disadvantage and biological diversity and species richness might be lost in some ecosystems. Our results indicate that isoprene emitting tree species will have an advantage over non-isoprene emitting ones under high temperatures

Maltose Biochemistry and Transport in Plant Leaves

Starch is a desirable plant product for both food and biofuel. Leaf starch is ideal for use in biofuels because it does not compete with grain starch, which is used for food. Starch is accumulated in plant leaves during the day and broken down at night. If we can manipulate leaf starch breakdown it may be possible to design a plant that provides both grain starch for food and leaf starch for biofuel. The pathway of leaf starch breakdown was not known when this work started. Preliminary evidence had shown that maltose was the primary product of leaf starch breakdown (Weise, Weber & Sharkey, 2004) and that it was metabolized by a disproportionating enzyme called amylomaltase but given the initials DPE2 (Lu & Sharkey, 2004). In this work we showed that only one form of maltose was metabolically active (Weise et al., 2005a) and that maltose was located in two different places when the amylomaltase was knocked out but only inside the chloroplast when the maltose transporter was knocked out (Lu et al., 2006a). This allowed us to estimate the energetics of maltose export and to show that maltose export is more efficient than glucose export (Weise et al., 2005b). We examined how daylength affected starch breakdown rate and found that starch breakdown rate could respond to changes in daylength within one day (Lu, Gehan & Sharkey, 2005). We also were able to show a second starch breakdown pathway by chloroplastic starch phosphorylase (Weise et al., 2006). Work to this point was summarized in a review (Lu & Sharkey, 2006). We were able to show that the amylomaltase in plants could substitute for the amylomaltase in bacteria (Lu et al., 2006b). In this paper we also showed the importance of a second enzyme called alpha-glucan phosphorylase in starch breakdown. Finally, we were able to determine the enzymatic mechanism of the amylomaltase (Steichen, Petty & Sharkey, 2008). These results have laid the groundwork for manipulating plants for improved biofuel production

Diet, nutrition, obesity and their role in arthritis

Obesity and poor nutrition, individually and together, have created costly musculoskeletal disease epidemic in the United States. Processed food, with abundant empty calories, has contributed greatly to our dietary woes. Much of the food consumed today is packed with calories but refined to the point that essential nutrients are lacking. Even worse, processed food may have ingredients added that are detrimental to good health. Abundant research has documented a close relationship between obesity, poor diet and orthopaedic problems. Dietary supplements have been proven to provide both disease prevention and therapeutic benefits. Unfortunately, many weight loss programs and methods are ineffective and possibly dangerous. Additionally, the FDA does not regulate the nutritional supplement industry and product quality is high variable. It is imperative that physicians treating patients with musculoskeletal complaints understand these disease producing relationships and have a network in place to refer patients to reputable weight loss entities and for high quality nutritional supplements

UBF levels determine the number of active ribosomal RNA genes in mammals

In mammals, the mechanisms regulating the number of active copies of the ∼200 ribosomal RNA (rRNA) genes transcribed by RNA polymerase I are unclear. We demonstrate that depletion of the transcription factor upstream binding factor (UBF) leads to the stable and reversible methylation-independent silencing of rRNA genes by promoting histone H1–induced assembly of transcriptionally inactive chromatin. Chromatin remodeling is abrogated by the mutation of an extracellular signal-regulated kinase site within the high mobility group box 1 domain of UBF1, which is required for its ability to bend and loop DNA in vitro. Surprisingly, rRNA gene silencing does not reduce net rRNA synthesis as transcription from remaining active genes is increased. We also show that the active rRNA gene pool is not static but decreases during differentiation, correlating with diminished UBF expression. Thus, UBF1 levels regulate active rRNA gene chromatin during growth and differentiation

The prevalence of disordered eating in elite male and female soccer players

PurposeTo examine the prevalence of disordered eating (DE) in elite male and female soccer players and the influence of perfectionism.MethodsUsing a cross-sectional design, elite male (n = 137) and female (n = 70) soccer players and non-athlete controls (n = 179) completed the clinical perfectionism questionnaire (CPQ-12) and the eating attitudes test (EAT-26) to assess perfectionism and DE risk, respectively.ResultsMale soccer players had higher EAT-26 scores than controls (10.4 ± 9.9 vs. 6.8 ± 6.7; P = 0.001), but there were no differences in the prevalence of clinical levels of DE (EAT-26 score ≥ 20) (15 vs. 5%, respectively; X2 = 0.079) The proportion of females with DE risk was higher in controls [EAT-26: 13.9 ± 11.6 (25% of population)] than female players [EAT-26: 10.0 ± 9.0% (11% of population)] (X2 = 0.001). With linear regression, perfectionism explained 20% of the variation in DE risk in males (P = 0.001); in females, athletic status (player vs. control) and perfectionism were significant predictors of DE risk, explaining 21% of the variation (P = 0.001). Male reserve team players had higher EAT-26 (+ 3.5) and perfectionism (+ 2.7) scores than first-team players (P ConclusionsThe prevalence of DE risk was not different in elite male and female soccer players; in fact, the prevalence was greatest in non-athlete female controls. Perfectionism is a significant predictor of DE risk in males and females.Level of evidenceIII, case–control study.</div

90Y-clivatuzumab tetraxetan with or without low-dose gemcitabine: A phase Ib study in patients with metastatic pancreatic cancer after two or more prior therapies

AbstractBackgroundFor patients with metastatic pancreatic adenocarcinoma, there are no approved or established treatments beyond the 2nd line. A Phase Ib study of fractionated radioimmunotherapy was undertaken in this setting, administering 90Y-clivatuzumab tetraxetan (yttrium-90-radiolabelled humanised antibody targeting pancreatic adenocarcinoma mucin) with or without low radiosensitising doses of gemcitabine.MethodsFifty-eight patients with three (2–7) median prior treatments were treated on Arm A (N=29, 90Y-clivatuzumab tetraxetan, weekly 6.5mCi/m2doses×3, plus gemcitabine, weekly 200mg/m2 doses×4 starting 1week earlier) or Arm B (N=29, 90Y-clivatuzumab tetraxetan alone, weekly 6.5mCi/m2doses×3), repeating cycles after 4-week delays. Safety was the primary endpoint; efficacy was also evaluated.ResultsCytopaenias (predominantly transient thrombocytopenia) were the only significant toxicities. Fifty-three patients (27 Arm A, 26 Arm B, 91% overall) completed ⩾1 full treatment cycles, with 23 (12 Arm A, 11 Arm B; 40%) receiving multiple cycles, including seven (6 Arm A, 1 Arm B; 12%) given 3–9 cycles. Two patients in Arm A had partial responses by RECIST criteria. Kaplan–Meier overall survival (OS) appeared improved in Arm A versus B (hazard ratio [HR] 0.55, 95% CI: 0.29–0.86; P=0.017, log-rank) and the median OS for Arm A versus Arm B increased to 7.9 versus 3.4months with multiple cycles (HR 0.32, P=0.004), including three patients in Arm A surviving >1year.ConclusionsClinical studies of 90Y-clivatuzumab tetraxetan combined with low-dose gemcitabine appear feasible in metastatic pancreatic cancer patients beyond 2nd line and a Phase III trial of this combination is now underway in this setting