Temperature memory and non-structural carbohydrates mediate legacies of a hot drought in trees across the southwestern USA

Trees are long-lived organisms that integrate climate conditions across years or decades to produce secondary growth. This integration process is sometimes referred to as 'climatic memory.' While widely perceived, the physiological processes underlying this temporal integration, such as the storage and remobilization of non-structural carbohydrates (NSC), are rarely explicitly studied. This is perhaps most apparent when considering drought legacies (perturbed post-drought growth responses to climate), and the physiological mechanisms underlying these lagged responses to climatic extremes. Yet, drought legacies are likely to become more common if warming climate brings more frequent drought. To quantify the linkages between drought legacies, climate memory and NSC, we measured tree growth (via tree ring widths) and NSC concentrations in three dominant species across the southwestern USA. We analyzed these data with a hierarchical mixed effects model to evaluate the time-scales of influence of past climate (memory) on tree growth. We then evaluated the role of climate memory and the degree to which variation in NSC concentrations were related to forward-predicted growth during the hot 2011-2012 drought and subsequent 4-year recovery period. Populus tremuloides exhibited longer climatic memory compared to either Pinus edulis or Juniperus osteosperma, but following the 2011-2012 drought, P. tremuloides trees with relatively longer memory of temperature conditions showed larger (more negative) drought legacies. Conversely, Pinus edulis trees with longer temperature memory had smaller (less negative) drought legacies. For both species, higher NSC concentrations followed more negative (larger) drought legacies, though the relevant NSC fraction differed between P. tremuloides and P. edulis. Our results suggest that differences in tree NSC are also imprinted upon tree growth responses to climate across long time scales, which also underlie tree resilience to increasingly frequent drought events under climate change.

Temporal controls on crown nonstructural carbohydrates in southwestern US tree species

In trees, large uncertainties remain in how nonstructural carbohydrates (NSCs) respond to variation in water availability in natural, intact ecosystems. Variation in NSC pools reflects temporal fluctuations in supply and demand, as well as physiological coordination across tree organs in ways that differ across species and NSC fractions (e.g., soluble sugars vs starch). Using landscape-scale crown (leaves and twigs) NSC concentration measurements in three foundation tree species (Populus tremuloides, Pinus edulis, Juniperus osteosperma), we evaluated in situ, seasonal variation in NSC responses to moisture stress on three timescales: short-term (via predawn water potential), seasonal (via leaf δ13C) and annual (via current year's ring width index). Crown NSC responses to moisture stress appeared to depend on hydraulic strategy, where J. osteosperma appears to regulate osmotic potentials (via higher sugar concentrations), P. edulis NSC responses suggest respiratory depletion and P. tremuloides responses were consistent with direct sink limitations. We also show that overly simplistic models can mask seasonal and tissue variation in NSC responses, as well as strong interactions among moisture stress at different timescales. In general, our results suggest large seasonal variation in crown NSC concentrations reflecting the multiple cofunctions of NSCs in plant tissues, including storage, growth and osmotic regulation of hydraulically vulnerable leaves. We emphasize that crown NSC pool size cannot be viewed as a simple physiological metric of stress; in situ NSC dynamics are complex, varying temporally, across species, among NSC fractions and among tissue types.

SAT0143 A PHASE 1 STUDY IN HEALTHY VOLUNTEERS EXPLORING THE SAFETY, PHARMACOKINETICS AND PHARMACODYNAMICS OF ATI-450: A NOVEL ORAL MK2 INHIBITOR

Background:

ATI-450, is an investigational small molecule inhibitor of the MAPK-activated protein kinase 2 (MK2) signaling pathway. This pathway drives the expression of multiple cytokines including TNFα, IL-1α and β, and IL-6.

Objectives:

We evaluated the safety and tolerability of ATI-450 in healthy volunteers as well as pharmacokinetics (PK) and pharmacodynamics (PD). Here we present data from single and multiple ascending dose cohorts. The aim was to select a dose for evaluation in phase 2 in patients with rheumatoid arthritis.

Methods:

Safety, PK and PD were assessed in a randomized, observer-blind, placebo-controlled, phase 1 study in male and female healthy subjects aged 18-55 (n=77).

Safety and tolerability of ATI-450 was evaluated based on adverse events, clinical laboratory, vital signs, 12-lead ECG, Holter monitoring, and physical examination. Blood was drawn for PK analysis at 0.5, 1, 2, 4, 6, 8, 12 hours, 24, 36, and 48 hours post dose in the SAD cohort and on day 7 of the MAD cohort. PD of ATI-450 were explored by investigating the inhibition of a target biomarker, phospho-HSP27 (pHSP27) and proinflammatory cytokines, TNFα, IL1β, IL6 and IL8 inex-vivoLPS-stimulated blood samples collected 4 and 12 hours post dose on day 7 from subjects in the MAD cohorts.

Results:

ATI-450 was generally well tolerated. No serious adverse events or severe adverse events were reported, and no adverse events led to discontinuation of the study medication. The most common adverse events (reported by 2 or more subjects who received ATI-450) observed during the trial were dizziness, headache, upper respiratory tract infection, constipation, nausea, and abdominal pain. All adverse events were mild. A trend of a decrease in absolute neutrophil count (ANC) was observed without correlated clinical sequelae.

ATI-450 had dose proportional PK with a terminal half-life (t½) of 9-12 hours in the MAD cohort on day 7. A dose and concentration dependent inhibition ofex vivostimulated cytokines and target biomarker was observed. On day 7, patients in the 50mg BID dose (the dose with the highest degree of inhibition) recorded mean trough drug levels (12 hours post dose) that were 1.4, 2.5, 2.5 and 2.4 times greater than the IC80for TNFα, IL1β, IL8 and pHSP27 respectively. Mean Cmax drug levels (4 hours post dose) were 3.6, 6.4, 6.2 and 6.0 times greater than the IC80for TNFα, IL1β, IL8 and pHSP27 respectively. IL6 levels were inhibited by more than 50% for part of the dosing interval.

Conclusion:

Oral ATI-450 was generally well tolerated at all doses with dose proportional PK. The t½ suggests that once or twice daily oral dosing may be possible. At the 50mg BID dose, marked inhibition of TNFα, IL1β and IL8, IL6 and pHSP27 was observed. ATI-450 has the potential to be an oral, small molecule drug which can target multiple cytokines. Exploration of its benefit to risk profile in patients with rheumatoid arthritis is warranted.

Disclosure of Interests:

Judy Schnyder Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Joe Monahan Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Walter Smith Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Heidi Hope Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Deborah Kelly Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, David Burt Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, E Huff Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, A Kaul Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, A Hildebrand Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, B Burnette Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, N Klug Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, M Bangs Shareholder of: Aclaris Therapeutics, Employee of: Aclaris Therapeutics, David Gordon Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics

INVESTIGATION OF MOSQUITOES WITH EMPHASIS ON AEDES (FINLAYA) POICILIUS, PUTATIVE VECTOR OF BANCROFTIAN FILARIASIS ON PANAY ISLAND, THE PHILIPPINES

Entomological investigations were conducted in four remaining lymphatic filariasis endemic provinces of Panay Island, The Philippines to determine mosquito species present in these areas and to identify host preference and biting activity of Aedes (Finlaya) poicilius Theobald, primary vector of nocturnal periodic Wuchereria bancrofti in The Philippines. Sampling techniques targeted nocturnally active mosquito species using a carabao-baited trap (CBT) and human-landing collection (HLC), the latter taking place from 06:00 to 12:00 pm. A total of 25,536 mosquitoes comprising 42 species and 7 genera were collected from CBT, whilst HLC acquired 6,486 mosquitoes comprising 28 species and 5 genera. Three known or potential vectors of human filarial were collected, namely, Aedes poicilius, Culex quinquefasciatus and Mansonia uniformis. The peak landing (biting) activity for Ae. poicilius was between 09:00 and 11:00 pm. Comparisons between CBT and HLC yields showed this species to be more zoophilic. Based on observed mosquito behavior and interviews with residents, vector-host contact was promoted by the local practice of staying overnight in makeshift shelters in high risk areas without adequate protection against mosquito bites. Results of this survey will augment information for integrating vector control and mass drug administration into an island-wide lymphatic filariasis elimination program.

A probability model of vector behavior: effects of DDT repellency, irritancy, and toxicity in malaria control

A probability model of how DDT residues may function within a malaria control program is described. A step-wise organization of endophagic behaviors culminates in a vector acquiring a human blood meal inside the house. Different vector behaviors are described, epidemiologically defined, temporally sequenced, and quantified with field data. Components of vector behavior and the repellent, irritant, and toxic actions of insecticide residues are then assembled into a probability model. The sequence of host-seeking behaviors is used to partition the total impact of sprayed walls according to the three chemical actions. Quantitatively, the combined effect of repellency and irritancy exert the dominant actions of DDT residues in reducing man-vector contact inside of houses. These relationships are demonstrated with published and unpublished data for two separate populations of Anopheles darlingi, for Anopheles gambiae and Anopheles funestus in Tanzania, and Anopheles punctulatus in New Guinea.

The role of prior pain experience and expectancy in psychologically and physically induced pain

Cognitive theories regarding symptom formation suggest that environmental factors such as warnings of impending pain and earlier experiences with pain can lead to a cognitive schema in which pain is selectively monitored. This study evaluated the role of prior experience with pain in the development of expectancy induced somatoform pain. Subjects from two experimental groups were connected to a sham stimulator and told to expect a headache. One of these groups, the physical stimulation first group, was exposed to pain induction by ice water and by pressure prior to the sham stimulation. A second group, the sham stimulation first group, received the sham stimulation followed by the cold water and pressure pain induction techniques. Subjects in the physical stimulation first group showed significant increases in their pain reports as settings on the sham stimulator were increased. Significant increases were not noted in the sham stimulation first group. The two groups did not differ in the number of subjects reporting pain or the mean maximal pain reported during the sham stimulation. Duration of cold water tolerance and the time until the analgesic threshold level for cold water were significantly shorter in subjects who had the sham stimulation first. This study suggests that prior pain can influence the reactivity to external suggestion for pain but does not increase the frequency of pain reports. It does suggest that the selective monitoring induced during the sham stimulation may influence later pain behaviours as was seen during the cold water tolerance testing.

Medical students' attitudes on specialist physicians' social and sexual contact with patients

To assess medical students' attitudes toward social and sexual contact with patients by physicians from three medical specialties (internal medicine, obstetrics-gynecology, and psychiatry), 326 students were surveyed at one medical school and 239 students responded (response rate = 73.3%). Most students perceived that arranging to date and/or dating and genital sexual contact were not appropriate either during a patient visit or concurrent with ongoing treatment. However, as many as 20% of the male students and 3.5% of the female students said that genital sexual contact with patients concurrent with treatment was (sometimes or usually) appropriate, depending on the specialty. Significant gender differences were found in attitudes about physician-patient sexual contact. Genital sexual contact was also significantly less likely to be perceived as appropriate for psychiatrists, as might be expected, than for obstetrician-gynecologists and internal medicine specialists. These results are discussed in relation to current codes of ethics.

National survey on physicians' attitudes toward social and sexual contact with patients

To determine the attitudes of physicians toward social and sexual contact with patients, we mailed a self-report survey to a nationwide randomized sample including general practitioners, internists, obstetrician-gynecologists, and ophthalmologists. The 777 physicians who responded specified whether or not behavior such as hugging, dating, and sexual contact with their own patients may be appropriate. Less than 1% of all respondents thought that sexual contact with patients was appropriate during patient consultations. Three percent of internists and obstetrician-gynecologists considered sexual contact with patients appropriate when concurrent with treatment but outside of patient consultation, as compared with 9% of general practitioners and 12% of ophthalmologists (X2 = 17.8, df = 3, P < .001). Nearly 50% of general practitioners and more than 50% of all other physicians thought that sexual contact might be appropriate after termination of treatment of a patient. These findings may facilitate professional discussion on standards for social and sexual contact with patients.

Anxiety in experimentally induced somatoform symptoms

This study examined the anxiety and pain reports in a group of subjects during a stimulation experiment in which the subjects were misinformed that an electrical current was being conducted through electrodes attached to their heads. The experiment's purpose was to determine how the subjects' reporting of pain was related to their reporting of anxiety over time. One subset of the subjects rated pain only, a second rated pain and anxiety, and a third rated pain and hunger. The three groups did not differ significantly in the frequency or intensity of their pain reports. The separate ratings for both anxiety and pain increased in a parallel manner. These results, however, do not support the theories involving the suppression of awareness of affect in somatofom disorders.