Cost-effective restoration for carbon sequestration across Brazil's biomes

Tropical ecosystems are central to the global focus on halting and reversing habitat destruction as a means of mitigating carbon emissions. Brazil has been highlighted as a vital part of global climate agreements because, whilst ongoing land-use change causes it to be the world's fifth biggest greenhouse gas emitting country, it also has one of the greatest potentials to implement ecosystem restoration. Global carbon markets provide the opportunity of a financially viable way to implement restoration projects at scale. However, except for rainforests, the restoration potential of many major tropical biomes is not widely recognised, with the result that carbon sequestration potential may be squandered. We synthesize data on land availability, land degradation status, restoration costs, area of native vegetation remaining, carbon storage potential and carbon market prices for 5475 municipalities across Brazil's major biomes, including the savannas and tropical dry forests. Using a modelling analysis, we determine how fast restoration could be implemented across these biomes within existing carbon markets. We argue that even with a sole focus on carbon, we must restore other tropical biomes, as well as rainforests, to effectively increase benefits. The inclusion of dry forests and savannas doubles the area which could be restored in a financially viable manner, increasing the potential CO₂e sequestered >40 % above that offered by rainforests alone. Importantly, we show that in the short-term avoiding emissions through conservation will be necessary for Brazil to achieve it's 2030 climate goal, because it can sequester 1.5 to 4.3 Pg of CO₂e by 2030, relative to 0.127 Pg CO₂e from restoration. However, in the longer term, restoration across all biomes in Brazil could draw down between 3.9 and 9.8 Pg of CO₂e from the atmosphere by 2050 and 2080.

The value of disease-free survival (DFS) and osimertinib in adjuvant non-small-cell lung cancer (NSCLC): an international Delphi consensus report

Background

Rates of disease recurrence and death following surgery remain high in early-stage non-small-cell lung cancer (NSCLC), despite adjuvant treatment and curative intent. Recently, osimertinib showed overwhelming evidence for disease-free survival (DFS), as demonstrated by an overall reduction in the risk of disease recurrence or death in the adjuvant setting of 80% versus control in the ADAURA study (stage IB-IIIA; hazard ratio 0.20; 99.12% confidence interval 0.14-0.30; P < 0.001). However, due to the early unblinding of ADAURA and lack of mature overall survival data, there is a need to qualitatively confirm consensus on the clinical and patient relevance of DFS.

Materials and methods

We conducted a modified Delphi panel study consisting of two rounds of surveys, followed by a consensus meeting. An international panel of experts in the field of NSCLC and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) (n = 13) was asked to rate agreement and comment on a list of pre-defined statements covering key consensus gaps. Statements were eliminated or updated between surveys, depending on the level of agreement. A final list of agreed-upon statements was drafted in the consensus meeting.

Results

Consensus was reached on 32 qualitative statements, with topics including unmet needs in early-stage NSCLC, the value of DFS, and the value of osimertinib. Crucially, DFS was agreed to be a clinically and patient-relevant endpoint in adjuvant NSCLC. The relevance of DFS was found to relate to the ability of an adjuvant therapy, such as osimertinib, to keep patients in the clinically valuable curative intent setting, while preventing the burden associated with distant and locoregional recurrence, and progressive disease.

Conclusions

Addressing the need for measures that reflect clinical benefit is essential to continue improving outcomes for NSCLC patients. To that end, this work provides a qualitative framework for clinicians to consider the clinical and patient relevance of DFS in adjuvant NSCLC and the benefit demonstrated in ADAURA thus far.

•

There is a need for qualitative consensus assessment of the clinical and patient relevance of DFS in the adjuvant setting.

•

An international panel of experts viewed DFS as a clinically and patient-relevant endpoint in adjuvant NSCLC.

•

DFS relevance in adjuvant therapy, e.g. osimertinib, relates to keeping early-stage patients in a curative intent setting.

•

Curative intent prevents or significantly delays locoregional and distant (CNS) recurrence burden and progressive disease.

Microbial composition and omasal flows of bacterial, protozoal, and nonmicrobial amino acids in lactating dairy cows fed fresh perennial ryegrass (Lolium perenne L.) not supplemented or supplemented with rolled barley

The objective of this study was to evaluate the effect of rolled barley supplementation on microbial composition and omasal flows of bacterial, protozoal, and nonmicrobial AA in cows fed fresh perennial ryegrass (Lolium perenne L.; PRG). Ten ruminally cannulated multiparous Holstein cows averaging (mean ± standard deviation) 49 ± 23 d in milk and 513 ± 36 kg of body weight were assigned to 1 of 2 treatments in a switchback design. The treatment diets were PRG only or PRG plus 3.5 kg of dry matter rolled barley (G+RB). The study consisted of three 29-d periods where each period consisted of 21 d of diet adaptation and 8 d of data and sample collection. A double-marker system was used to quantify nutrient flow entering the omasal canal along with ¹⁵N-ammonium sulfate to label and measure the microbial and nonmicrobial omasal flow of AA. Overall, rolled barley supplementation had no effect on the AA composition of the omasal liquid-associated and particle-associated bacteria. Rolled barley supplementation affected the AA concentrations of omasal protozoa; however, the differences were nutritionally minor. Particle-associated bacteria AA flow was increased for all AA, except for Trp and Pro, in cows fed the G+RB diet. Rolled barley supplementation had no effect on protozoal AA flow. On average, protozoa accounted for 23% of the microbial essential AA flow, which ranged from 17 to 28% for Trp and Lys, respectively. The flow of all AA in omasal true digesta increased in cows fed the G+RB diet compared with the PRG-only diet, resulting in a 228 g/d increase in total AA flow in cows fed the G+RB diet. This increase in total AA flow in cows fed the G+RB diet was due to an increase in microbial AA flow. Rolled barley supplementation had no effect on nonmicrobial AA flow. The nonmicrobial AA flow modestly contributed to total AA flow, accounting for 15.6% on average. These results indicated that extensive ruminal degradation of PRG AA occurred (83.5%), and we demonstrated that cows consuming PRG-based diets exhibit a large dependence on microbial AA to support metabolizable AA supply. Rolled barley supplementation can increase the omasal flow of microbial AA in cows consuming PRG-based diets. However, further research is required to elucidate if this increased AA supply can support higher milk yield under such dietary conditions.

Rumen metabolism, omasal flow of nutrients, and microbial dynamics in lactating dairy cows fed fresh perennial ryegrass (Lolium perenne L.) not supplemented or supplemented with rolled barley grain

The objective of this study was to evaluate the effect of rolled barley grain (RB) supplementation on rumen metabolism, omasal flow of nutrients, and microbial dynamics in lactating dairy cows fed fresh perennial ryegrass (Lolium perenne L.; PRG)-based diets. Ten ruminally cannulated Holstein cows averaging (mean ± standard deviation) 49 ± 23 d in milk and 513 ± 36 kg of body weight were assigned to 1 of 2 treatments in a switchback design. The treatment diets were PRG only (G) or PRG plus 3.5 kg of dry matter RB (G+RB). The study consisted of three 29-d periods where each period consisted of 21 d of diet adaptation and 8 d of data and sample collection. A double marker system was used to quantify nutrient flow entering the omasal canal along with labeled ¹⁵N-ammonium sulfate to measure bacterial, protozoal, and nonmicrobial N flow. Rumen evacuation techniques were used to determine nutrient and microbial pool size, allowing the calculation of fractional rates of digestion and microbial growth. There was no difference in daily milk yield or energy-corrected milk yield between treatments. Milk fat concentration and milk urea N decreased, whereas milk protein concentration increased in cows fed the G+RB diet. During the omasal sampling phase, dry matter intake was higher in cows fed the G+RB diet. Ruminal and total-tract neutral detergent fiber digestibility was lower in G+RB cows; however, no difference was observed in reticulorumen pH. The rumen pool size of fermentable carbohydrate was increased in cows fed the G+RB diet; however, the fractional rate of digestion was decreased. Flow of nonammonia N and bacterial N at the omasal canal increased in cows fed the G+RB diet compared with the G diet. Protozoa N flow was not different between diets; however, protozoa appeared to supply a much larger amount of microbial N and exhibited shorter generation time than previously considered. Feed N ruminal digestibility, corrected for microbial contribution, was similar for both treatments (88.4 and 89.0% for G and G+RB, respectively). In conclusion, RB supplementation did not benefit overall animal performance; however, it reduced ruminal neutral detergent fiber digestibility and increased bacterial N flow. The results demonstrate the large dependence of cows consuming PRG-based diets on microbial N as the main source of nonammonia N supply. Additional quantitative research is required to further describe the supply of nutrients and microbial dynamics in cows consuming PRG-based diets in an effort to determine most limiting nutrients.

0340 Regional Changes in Sleep Electroencephalography Power in Youth with Sleep-Disordered Breathing: A High-Density EEG Study

Introduction

Daytime neurobehavioral impairments are commonly associated with sleep disordered breathing (SDB) in children. However, a large number of studies have shown only minimal differences in sleep between children with SDB relative to control children, suggesting that sleep dysfunction is not responsible for daytime impairment. Importantly, however, previous studies have measured sleep EEG using only frontal scalp electrodes, failing to capture the regional features of sleep that are prominent during development. Here we measure sleep using hdEEG in SDB and healthy children to determine if regional sleep impairment is related to daytime neurobehavioral performance.

Methods

Overnight high-density electroencephalography (hdEEG, 256 channels) was recorded in 17 children with sleep disordered breathing (SDB) (age: M = 8.46, SD = 1.82, AHI: M = 11.3, SD = 8.6, 53% female) and 17 age and sex matched controls (age: M = 8.47, SD = 1.66, AHI: M = 1.5, SD = .64). Attentional capacity was assessed using the Test of Variables of Attention (TOVA) before and after sleep. Group differences in sleep macrostructure variables were assessed using unpaired t-tests. All-night spectral analysis was performed for NREM sleep and averaged across groups. Topographic differences between groups were assessed using statistical non-parametric mapping. Pearson correlations were used to determine associations between sleep and TOVA variables.

Results

Sleep macrostructure did not differ between groups. All-night spectral density analysis revealed a global increase in high-frequency activity in N2N3 and N3, in the alpha band (8-12 Hz, p&lt;0.05). Global alpha power was higher in SDB youth, although this effect reached significance during N3 in a large cluster of posterior channels (N=55, p=.02).

Conclusion

Elevated alpha during NREM is frequently considered a correlate of nonrestorative sleep. In this sample of youth with SDB, posterior alpha is robustly increased during the deepest stage of NREM sleep. In this small sample, however, alpha power did not predict performance on an attentional task sensitive to the effects of impaired sleep.

Support

R21 HD092986-02 to SJ

Magnetic Resonance Imaging of Cerebral Small Vessel Disease in Men Living with HIV and HIV-Negative Men Aged 50 and Above

We assessed whether HIV status was associated with white matter hyperintensities (WMH), a neuroimaging correlate of cerebral small vessel disease (CSVD), in men aged ≥50 years. A cross-sectional substudy was nested within a larger cohort study. Virologically suppressed men living with HIV (MLWH) and demographically matched HIV-negative men aged ≥50 underwent magnetic resonance imaging (MRI) at 3 Tesla. Sequences included volumetric three-dimensional (3D) T1-weighted, fluid-attenuated inversion recovery and pseudocontinuous arterial spin labeling. Regional segmentation by automated image processing algorithms was used to extract WMH volume (WMHV) and resting cerebral blood flow (CBF). The association between HIV status and WMHV as a proportion of intracranial volume (ICV; log-transformed) was estimated using a multivariable linear regression model. Thirty-eight MLWH [median age 59 years (interquartile range, IQR 55-64)] and 37 HIV-negative [median 58 years (54-63)] men were analyzed. MLWH had median CD4⁺ count 570 (470-700) cells/μL and a median time since diagnosis of 20 (14-24) years. Framingham 10-year risk of cardiovascular disease was 6.5% in MLWH and 7.4% in controls. Two (5%) MLWH reported a history of stroke or transient ischemic attack and five (13%) reported coronary heart disease compared with none of the controls. The total WMHV in MLWH was 1,696 μL (IQR 1,229-3,268 μL) or 0.10% of ICV compared with 1,627 μL (IQR 1,032-3,077 μL), also 0.10% of ICV in the HIV-negative group (p = .43). In the multivariable model, WMHV/ICV was not associated with HIV status (p = .86). There was an age-dependent decline in cortical CBF [-3.9 mL/100 mL/min per decade of life (95% confidence interval 1.1-6.7 mL)] but no association between CBF and HIV status (p > .2 in all brain regions analyzed). In conclusion, we found no quantitative MRI evidence of an increased burden of CSVD in MLWH aged 50 years and older.

"They're kept in a bubble": Healthcare professionals' views on transitioning young adults with congenital heart disease from paediatric to adult care

BACKGROUND

Due to medical advances, growing numbers of adolescents with congenital heart disease (CHD) survive into adulthood and transferring from paediatric to adult healthcare. This transfer is significant step in a young person's life, and this study examines the views of Irish healthcare professionals' on how best to manage this transition.

METHODS

Purposeful sampling was used to invite participation by healthcare professionals (HCPs) from a variety of disciplines whose caseloads include adolescents and young adults with CHD. Fourteen professionals participated in semistructured interviews regarding their experiences of the transition process and their recommendations. Data were collected during Spring 2016 and analysed using thematic analysis.

RESULTS

Results indicated that the current approach to transition and transfer could be improved. Professionals identified barriers hindering the transition process such as cultural and attitudinal differences between HCPs dealing with child and adult patients, inadequate preparation and education of patients about their condition, parental reluctance to transfer, and concern about parents' role in on-going treatment. Measures such as better support and education for both the patients and their parents were recommended, in order to facilitate a smoother transition process for all parties involved. Additionally, HCPs identified the need for better collaboration and communication, both between paediatric and adult healthcare professionals and between hospitals, to ensure greater continuity of care for patients.

CONCLUSIONS

Action is required in order to improve the current transition process. Measures need to be taken to address the barriers that currently prevent a smooth transition process for young adult CHD patients. Professionals recommended the implementation of a structured transition clinic to deal with the wide variety of needs of transitioning adolescent patients and their families. Recommendations for future research are also made.

Technical pre-analytical effects on the clinical biochemistry of Atlantic salmon (Salmo salar L.)

Clinical biochemistry has long been utilized in human and veterinary medicine as a vital diagnostic tool, but despite occasional studies showing its usefulness in monitoring health status in Atlantic salmon (Salmo salar L.), it has not yet been widely utilized within the aquaculture industry. This is due, in part, to a lack of an agreed protocol for collection and processing of blood prior to analysis. Moreover, while the analytical phase of clinical biochemistry is well controlled, there is a growing understanding that technical pre-analytical variables can influence analyte concentrations or activities. In addition, post-analytical interpretation of treatment effects is variable in the literature, thus making the true effect of sample treatment hard to evaluate. Therefore, a number of pre-analytical treatments have been investigated to examine their effect on analyte concentrations and activities. In addition, reference ranges for salmon plasma biochemical analytes have been established to inform veterinary practitioners and the aquaculture industry of the importance of clinical biochemistry in health and disease monitoring. Furthermore, a standardized protocol for blood collection has been proposed.

On the long-time integration of stochastic gradient systems

This article addresses the weak convergence of numerical methods for Brownian dynamics. Typical analyses of numerical methods for stochastic differential equations focus on properties such as the weak order which estimates the asymptotic (stepsize h → 0 ) convergence behaviour of the error of finite-time averages. Recently, it has been demonstrated, by study of Fokker–Planck operators, that a non-Markovian numerical method generates approximations in the long-time limit with higher accuracy order (second order) than would be expected from its weak convergence analysis (finite-time averages are first-order accurate). In this article, we describe the transition from the transient to the steady-state regime of this numerical method by estimating the time-dependency of the coefficients in an asymptotic expansion for the weak error, demonstrating that the convergence to second order is exponentially rapid in time. Moreover, we provide numerical tests of the theory, including comparisons of the efficiencies of the Euler–Maruyama method, the popular second-order Heun method, and the non-Markovian method.

Protein engineering and preclinical development of a GM-CSF receptor antibody for the treatment of rheumatoid arthritis

BACKGROUND AND PURPOSE

For antibody therapies against receptor targets, in vivo outcomes can be difficult to predict because of target-mediated clearance or antigen 'sink' effects. The purpose of this work was to engineer an antibody to the GM-CSF receptor α (GM-CSFRα) with pharmacological properties optimized for chronic, s.c. treatment of rheumatoid arthritis (RA) patients.

EXPERIMENTAL APPROACH

We used an in silico model of receptor occupancy to guide the target affinity and a combinatorial phage display approach for affinity maturation. Mechanism of action and internalization assays were performed on the optimized antibody in vitro before refining the modelling predictions of the eventual dosing in man. Finally, in vivo pharmacology studies in cynomolgus monkeys were carried out to inform the predictions and support future clinical development.

KEY RESULTS

Antibody potency was improved 8600-fold, and the target affinity was reached. The refined model predicted pharmacodynamic effects at doses as low as 1 mg kg(-1) and a study in cynomolgus monkeys confirmed in vivo efficacy at 1 mg kg(-1) dosing.

CONCLUSIONS AND IMPLICATIONS

This rational approach to antibody drug discovery enabled the isolation of a potent molecule compatible with chronic, s.c. self-administration by RA patients. We believe this general approach enables the development of optimal biopharmaceuticals.

Incidence of serious side effects with intravenous bisphosphonate: a clinical audit

BACKGROUND

Bisphosphonates (BP) have been associated with osteonecrosis of the jaw (ONJ) and atypical femoral fractures (AFF). The prevalence of these side effects in intravenous (IV) BP-treated subjects is not well understood.

AIM

This audit aimed to delineate the prevalence of ONJ, thigh pain and AFF in patients having regular IV BP and its effect on bone mineral density (BMD). Design and

METHODS

Patients attending for IV BP over a 3-month period completed a questionnaire about thigh pain and dental health. Data concerning BMD, treatment indication and treatment history were obtained from medical records.

RESULTS

There were 201 patients between 28 and 94 years (74.1% female) mostly on zoledronate (ZOL) (102) or pamidronate (PAM) (97). Osteoporosis (75.6%) and Paget's disease (16.5%) were the main indications for treatment; median length of IV BP was 4 years (range 0.25-25). One patient had ONJ (0.5%) while oral pain was reported by 6.5% and 12.7% noted tooth loosening. Twenty-seven subjects (13.4%) complained of current thigh pain. AFF occurred in four patients (2%), none of whom had idiopathic osteoporosis. At time of AFF, only one patient had a femoral neck T-score less than -2.5. All four had received pamidronate treatment; median 12.5 years (range 7-22). IV BP treatment significantly increased lumbar spine BMD but not femoral neck BMD.

CONCLUSION

Classical ONJ was rare (0.5%), although tooth loss was more frequent. Thigh pain was frequent while AFF occurred in 2.0% of subjects and was associated with long treatment periods and non-osteoporotic bone.

Large body size and sedentary lifestyle during childhood and early adulthood and esophageal squamous cell carcinoma in a high-risk population

BACKGROUND

Little is known about the association of obesity and physical activity at young ages with subsequent risk of esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Between 2003 and 2007, we conducted a case-control study in a high-risk population in northeastern Iran. Three hundred ESCC cases and 571 matched controls were recruited. Each individual was shown a standard pictogram, to report body size at ages 15 and 30. Demographic and health-related information, including physical activity at these ages was also collected.

RESULTS

In the fully adjusted models, very obese body size (last two pictograms) at age 15 [odds ratio (OR) 3.2, 95% confidence interval (CI) 1.3-7.7] and age 30 (OR 3.1; 95% CI 1.1-8.5) were associated with ESCC in women, but not in men. Sedentary work at age 15 (OR 3.3, 95% CI 1.3-8.3) and 30 (OR 18.2, 95% CI 3.9-86.2) were also associated with ESCC risk in women only. The increased risk in women at age 15 remained high after later reduction in body size, while women who became very obese only at age 30 did not show a significantly increased risk.

CONCLUSION

These results highlight the importance of early lifestyle modifications in the context of cancer prevention, particularly in women.

A phase I clinical trial of the notch inhibitor MK-0752 in patients with T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) and other leukemias

6585

Background: Functional screening of T-ALL cell lines for sensitivity to NOTCH inhibitors has led to the discovery of frequent NOTCH1 gain-of-function mutations in the majority of human T-ALL. Gamma secretase catalyzes the cleavage of the Notch receptor within the transmembrane domain thereby releasing the Notch intracellular domain, which translocates to the nucleus to activate transcription of target genes. Gamma secretase inhibitors can induce G0/G1 arrest, decrease cell viability, and cause apoptosis of T-ALL cell lines carrying Notch activating mutations. MK-0752 is a potent gamma secretase inhibitor in clinical development (IC50 ∼50 nM). Methods: Patients with relapsed T-ALL and other leukemias were enrolled using an accelerated dose escalation scheme with 1 patient/dose level until ≥ grade 2 toxicity, followed by 3–6 patients/level. MK-0752 was administered by once-daily oral dosing in 28 day cycles. DLT was grade 3 or 4 non-hematologic toxicity during cycle 1. Plasma pharmacokinetic (PK) profiles and Abeta40 peptide levels were measured. Results: Six adult and two pediatric patients with leukemia (seven with T-ALL and one with AML) received MK-0752 dosed at 150, 225, and 300 mg/m2. Treatment duration ranged from 2 days to 56 days before patients discontinued for disease progression or drug-related toxicity. Dose-limiting toxicity (DLT) was Grade 3/4 diarrhea at 300 mg/m2. Four of the seven T-ALL patients had Notch activating mutations. One patient with T-ALL and a Notch activating mutation treated with 150 mg/m2 (300 mg) daily achieved a 45% reduction in a mediastinal mass at the end of 28 days as best response, but subsequently progressed by 56 days. Mean PK parameters at 150, 225, and 300 mg/m2 on Day 1 were AUC0–24hr = 723, 754, 1592 μM·hr, Cmax = 55, 40, 121 μM, C24hr = 18, 28, 59 μM, and tmax = 1, 8, 9 hr. Measurements of gamma secretase inhibition showed a 24–69% decrease in plasma Abeta40 peptide levels on Day 14 compared to predose. Conclusions: MK-0752 was well-tolerated in a limited number of patients below 300 mg/m2, and further enrollment is underway to establish the MTD. Plasma concentrations of MK-0752 at all doses were sufficient to inhibit gamma secretase. Leukemia samples will be assessed for Notch inhibition.

[Table: see text]

Phase I pharmacokinetic (PK), and pharmacodynamic (PD) trial of the novel oral Notch inhibitor MK-0752 in patients (pts) with advanced breast cancer (BC) and other solid tumors

10574

Introduction: Activation of Notch signaling occurs in ∼40% of human BCs and high Notch expression is associated with poor outcome. Inhibition of Notch inhibits BC cell proliferation in vitro. Notch signaling requires gamma secretase (GS), which cleaves Notch, releasing the Notch intracellular domain (NICD) to activate transcription of target genes. MK-0752 is a potent GS inhibitor. Methods: In Part 1 of the study, pts with advanced solid tumors were enrolled using an accelerated dose escalation with 1 pt/dose level until the occurrence of ≥Grade 2 toxicity, then 3–6 pts/dose level. MK-0752 was administered by once-daily oral dosing in 28-day cycles. Once a maximum tolerated dose (MTD) was established, an additional 22 pts with advanced BC were to be enrolled in Part 2. Six-point PK plasma profiles were collected over 24 hours on Days 1 and 28 and assayed by LC/MS/MS. PD measurement of plasma Abeta40 peptide (another gamma secretase substrate) was performed pre/post dose on Days 1 and 28. Tumor biopsies on Days 1 and 28 were obtained from a subset of pts to assess changes in Notch activity by immunohistochemical analysis of NICD. Results: In Part 1, two pts were enrolled at 450mg daily, and five pts at 600mg daily. Dose-limiting toxicities (DLTs) were Grade 3 diarrhea, constipation, nausea, and abdominal cramping at 600 mg. In Part 2, an additional 14 pts with BC were enrolled at 450mg daily. In this cohort, Grade 2/3 fatigue requiring dose reduction occurred in 6 pts. Grade 3 diarrhea (1pt), nausea (1 pt) and elevated liver transaminases (2 pt) were also observed. Mean PK parameters (at 450mg, 600 mg) on Day 1 were AUC0–24hr = 1036, 1065μM·hr, Cmax = 72, 61μM, C24hr = 25, 32μM, and tmax = 3, 7 hr. PD measurements of GS inhibition showed a 12–78% (mean 46%) decrease in plasma Abeta40 at 4 hours on Day 1 compared to predose. Conclusion: Continuous dosing of MK-0752 at 450mg daily in pts with BC was associated with significant toxicity, predominantly fatigue, and cannot be considered a MTD. An intermittent dosing schedule is being explored. MK-0752 at all doses inhibited GS, as demonstrated by decreases in plasma Abeta40. Analysis of efficacy and intratumoral Notch inhibition will be reported at the meeting.

[Table: see text]

Physical activity staging distribution: Establishing a heuristic using multiple studies

The purpose of this study was to identify the population prevalence across the stages of change (SoC) for regular physical activity and to establish the prevalence of people at risk. With support from the National Institutes of Health, the American Heart Association, and the Robert Wood Johnson Foundation, nine Behavior Change Consortium studies with a common physical activity SoC measure agreed to collaborate and share data. The distribution pattern identified in these predominantly reactively recruited studies was Precontemplation (PC) = 5% (+/- 10), Contemplation (C) = 10% (+/- 10), Preparation (P) = 40% (+/- 10), Action = 10% (+/- 10), and Maintenance = 35% (+/- 10). With reactively recruited studies, it can be anticipated that there will be a higher percentage of the sample that is ready to change and a greater percentage of currently active people compared to random representative samples. The at-risk stage distribution (i.e., those not at criteria or PC, C, and P) was approximately 10% PC, 20% C, and 70% P in specific samples and approximately 20% PC, 10% C, and 70% P in the clinical samples. Knowing SoC heuristics can inform public health practitioners and policymakers about the population's motivation for physical activity, help track changes over time, and assist in the allocation of resources.

Can diagnostic triage by general practitioners or rheumatology nurses improve the positive predictive value of referrals to early arthritis clinics?

OBJECTIVES

To determine whether diagnostic triage by general practitioners (GPs) or rheumatology nurses (RNs) can improve the positive predictive value of referrals to early arthritis clinics (EACs).

METHODS

Four GPs and two RNs were trained in the assessment of early inflammatory arthritis (IA) by four visits to an EAC supervised by hospital rheumatologists. Patients referred to one of three EACs were recruited for study and assessed independently by a GP, an RN and one of six rheumatologists. Each assessor was asked to record their clinical findings and whether they considered the patient to have IA. Each was then asked to judge the appropriateness of the referral according to predetermined guidelines. The rheumatologists had been shown previously to have a satisfactory level of agreement in the assessment of IA.

RESULTS

Ninety-six patients were approached and all consented to take part in the study. In 49 cases (51%), the rheumatologist judged that the patient had IA and that the referral was appropriate. The assessments of GPs and RNs were compared with those of the rheumatologists. Levels of agreement were measured using the kappa value, where 1.0 represents total unanimity. The kappa value was 0.77 for the GPs when compared with the rheumatologists and 0.79 for the RNs. Significant stiffness in the morning or after rest and objective joint swelling were the most important clinical features enabling the GPs and RNs to discriminate between IA and non-IA conditions.

CONCLUSION

Diagnostic triage by GPs or RNs improved the positive predictive value of referrals to an EAC with a degree of accuracy approaching that of a group of experienced rheumatologists.

Periodic maternal separation of neonatal rats produces region- and gender-specific effects on biogenic amine content in postmortem adult brain

Early environment exerts profound effects on mammalian behavioral and neural development. The aim of this study was to describe changes in adult neurochemistry in the rat following repeated neonatal maternal separation (RMS) during the preweaning period, a procedure known to induce enduring behavioral effects. Following RMS, rats show an attenuated locomotor response to novelty, to D-amphetamine, and attenuated behavioral responses for conditioned incentives as adults. These behavioral effects are broadly opposite in direction to those found following postweaning isolation rearing. Isolation rearing-induced behavioral changes are associated with profound changes in central monoamine function. Following RMS, adult rats had increased tissue levels of dopamine in both dorsal and ventral striatum. The turnover of dopamine, as determined by the ratio of DOPAC to dopamine, was decreased in the mPFC of RMS subjects. Serotonin levels were reduced in dorsal hippocampus of RMS rats of both sexes and in the mPFC of male RMS rats. Noradrenaline levels were increased in the dorsal hippocampus in female, but not in male, RMS rats. These data provide evidence that, in addition to the adult behavioral consequences, RMS leads to profound, region-, and gender-specific changes in brain monoamine content. The developmental specificity of these results is discussed with respect to their possible role in altered behavioral development and psychopathology.

Genome screening for linkage disequilibrium in a Costa Rican sample of patients with bipolar-I disorder: a follow-up study on chromosome 18

Linkage disequilibrium (LD) methods offer great promise for mapping complex traits, but have thus far been applied sparingly. In this paper we describe an LD mapping study of severe bipolar disorder (BP-I) in the genetically isolated population of the Central Valley of Costa Rica. This study provides the first complete screen of a chromosome for a complex trait using LD mapping and presents the first application of a new LD mapping statistic (ancestral haplotype reconstruction (AHR)) that evaluates haplotype sharing among affected individuals. The results of this chromosome-wide analysis are instructive for genome-wide LD mapping in isolated populations. Furthermore, the analysis continues to support a possible BP-I locus on 18pter, suggested by previous analyses in this population. Evidence for a possible BP-I locus on 18q12.2 is also described.

Bilingual health communicators: role delineation issues

Managers of health care services are seeking new opportunities to improve communication with clients who have limited English proficiency. An increase in bilingual health staff and the frequent use of their language skills in patient encounters provides opportunities but also brings with it confusion surrounding the role of interpreters and bilingual health staff. Secondary analysis of transcripts from 18 focus groups with monolingual and bilingual health staff has provided a method of distinguishing the roles of these complementary communicators. This paper clarifies the roles of interpreters and bilingual communication facilitators using seven key features: scope of language, language proficiency, nature of communication/interaction, nature of the contact and relationship, client responsibilities, and relationship with other health care providers. We discuss differences in how bilingual health staff use language when providing care, and alternative types of interactions interpreters could adopt to extend their current role. A collaborative group of communicators located within a health team is proposed, that is able to identify need and select the best communicator for the task.

Cardiorespiratory and thermoregulatory response of working in fire-fighter protective clothing in a temperate environment

The cardiorespiratory and thermal responses of two intensities of treadmill exercise were compared for brief periods (12 min) in fire ensemble (FE) but without self contained breathing apparatus, and sports ensemble (SE), in a temperature environment. A further experiment explored the responses of subjects exercising in FE over a prolonged period (60 min). Eighteen male fire-fighters wearing either FE or SE walked on a level treadmill for 6 min at 5 km x h(-1) increasing to 7 km x h(-1) for 6 min. Following a recovery interval of 1 h, the exercise protocol was repeated in the second ensemble; the order of ensemble was balanced. Heart rate (HR), rectal temperature (Tre), VO2 max and rating of perceived exertion (RPE) were monitored continuously under both ensembles. At 7 km x h(-1), VO2 was significantly higher (p<0.05) in FE (36.1 and 39.9 ml x kg(-1) x min(-1)) than in SE and represented 74% VO2 max. There were no changes Tre. In experiment 2, following a rest interval of at least 36 h, eight subjects in FE walked on the treadmill at 6 km x h (gradient 10%) for 60 min also in temperate conditions, where HR, Tre and RPE were recorded at 10-min intervals. During the 60-min exercise in FE, HR reached 161 beats x min(-1) and Tre increased to 38.3 degrees C. Despite considerable subject discomfort, Tre remained below dangerous levels (38.4 degrees C). When RPE were compared with a physiological strain index (PSI) calculated from Tre and HR data over 60 min, there was no significant difference (p<0.05) with a correlation coefficient (r) of 0.98. The results suggest that RPE and PSI are closely related when exercise is sufficiently prolonged or intense to elevate Tre and HR in fire-fighters wearing FE in temperate conditions. If further investigation confirms this relationship for hot humid conditions in which fire-fighters operate, then with training, it may provide individuals with a valid measure of dangerous levels of perceived heat strain.

Role modelling: how does it influence teaching in Family Medicine?

OBJECTIVE

To undertake a qualitative study to explore the influence of role modelling on teaching by comparing faculty members recollections of their teachers' behaviours with residents perceptions of the same behaviours in a family medicine residency programme in Saudi Arabia.

METHOD

Using semi-structured interviews of faculty and a questionnaire based on the issues arising from the interviews, faculty members' recollections of their medical teachers' behaviours were compared with residents' current perceptions of the same teaching behaviours.

SETTING

Department of Family Medicine, King Fahad National Guard Hospital, Riyadh, Saudi Arabia.

SUBJECTS

Faculty and residents.

RESULTS

The four best-remembered teacher behaviours were: positive behaviour towards patients, negative behaviour towards junior colleagues, effective presentation of subject content and encouragement to participate in patient care. The residents perceived positive behaviour towards patients, positive behaviour towards junior colleagues, suboptimal skills of subject content presentation, and insufficient encouragement for trainees to actively participate in patient management. Although faculty retained many unhappy memories of teacher behaviour, it was encouraging that there was no evidence of perpetuation of the negatively perceived behaviours which provoked them.

CONCLUSIONS

Discernment of the value of technical teaching skills was not a predictor of later proficiency.

Dose-dependence of 4-aminopyridine plasma concentrations and electrophysiological effects in dogs : potential relevance to ionic mechanisms in vivo

BACKGROUND

Previous investigators have administered 4-aminopyridine (4AP) to dogs to evaluate the role of transient outward current (I(to)) in vivo; however, plasma concentrations of 4AP were not measured, and it is therefore uncertain which cardiac ion channels were blocked at the concentrations achieved.

METHODS AND RESULTS

We applied high-performance liquid chromatography to measure 4AP concentrations produced by intravenous 4AP administration to dogs. A previously described dose regimen produced plasma concentrations that increased during the maintenance infusion but never exceeded 250 micromol/L and caused significant mortality. Whole-cell patch-clamp experiments on isolated canine myocytes showed that even the maximum 4AP concentrations achieved in vivo failed to alter ventricular I(to) and had very small effects on atrial I(to); however, concentrations achieved in vivo had a strong inhibitory effect on the dog ultrarapid delayed rectifier (I(Kur.d)), present only in atrial cells. We designed a loading and maintenance infusion regimen to produce stable 4AP plasma concentrations. At concentrations in the range of 25 and 50 micromol/L, 4AP had no effect on ventricular refractory period but increased atrial refractoriness significantly, consistent with the results of voltage clamp studies.

CONCLUSIONS

The interpretation of previous studies using intravenous 4AP administration to inhibit I(to) in dogs in vivo needs to be reevaluated in light of the fact that the infusion regimens used produce plasma concentrations that are inadequate to affect ventricular I(to). Our findings also support the concept that selective inhibition of ultrarapid delayed rectifier current can prolong atrial refractory periods without affecting ventricular refractoriness.

Poly-L-lysine improves gene transfer with adenovirus formulated in PLGA microspheres

In vivo gene transfer with recombinant adenovirus vectors can be hindered by the immunogenicity of the adenovirus capsid proteins. Previous work showed that formulation of the vector with biodegradable polymers such as poly-lactic-glycolic acid (PLGA), polyethylene glycol (PEG), or lipids, may shield the virus from inhibition by neutralizing antibodies. Formulation of adenovirus in PLGA microspheres also allowed for extended release in vitro. In experiments described here, we found that the surfactant used in the formation of the primary emulsion could significantly improve the overall yield of virus released. We also tested the effects of adding poly-L-lysine to adenovirus before encapsulation with PLGA. Our results show that although PLL did not effect the yield of virus encapsulated or released from the microspheres, it significantly improved the efficiency of gene transfer after release from the polymer.