Divergence with gene flow within the recent chipmunk radiation (Tamias)

Increasing data have supported the importance of divergence with gene flow (DGF) in the generation of biological diversity. In such cases, lineage divergence occurs on a shorter timescale than does the completion of reproductive isolation. Although it is critical to explore the mechanisms driving divergence and preventing homogenization by hybridization, it is equally important to document cases of DGF in nature. Here we synthesize data that have accumulated over the last dozen or so years on DGF in the chipmunk (Tamias) radiation with new data that quantify very high rates of mitochondrial DNA (mtDNA) introgression among para- and sympatric species in the T. quadrivittatus group in the central and southern Rocky Mountains. These new data (188 cytochrome b sequences) bring the total number of sequences up to 1871; roughly 16% (298) of the chipmunks we have sequenced exhibit introgressed mtDNA. This includes ongoing introgression between subspecies and between both closely related and distantly related taxa. In addition, we have identified several taxa that are apparently fixed for ancient introgressions and in which there is no evidence of ongoing introgression. A recurrent observation is that these introgressions occur between ecologically and morphologically diverged, sometimes non-sister taxa that engage in well-documented niche partitioning. Thus, the chipmunk radiation in western North America represents an excellent mammalian example of speciation in the face of recurrent gene flow among lineages and where biogeography, habitat differentiation and mating systems suggest important roles for both ecological and sexual selection.

What parents want from doctors in end-of-life decision-making for children

OBJECTIVE

End-of-life decision-making is difficult for everyone involved, as many studies have shown. Within this complexity, there has been little information on how parents see the role of doctors in end-of-life decision-making for children. This study aimed to examine parents' views and experiences of end-of-life decision-making.

DESIGN

A qualitative method with a semistructured interview design was used.

SETTING

Parent participants were living in the community.

PARTICIPANTS

Twenty-five bereaved parents.

MAIN OUTCOMES

Parents reported varying roles taken by doctors: being the provider of information without opinion; giving information and advice as to the decision that should be taken; and seemingly being the decision maker for the child. The majority of parents found their child's doctor enabled them to be the ultimate decision maker for their child, which was what they very clearly wanted to be, and consequently enabled them to exercise their parental autonomy. Parents found it problematic when doctors took over decision-making. A less frequently reported, yet significant role for doctors was to affirm decisions after they had been made by parents. Other important aspects of the doctor's role were to provide follow-up support and referral.

CONCLUSIONS

Understanding the role that doctors take in end-of-life decisions, and the subsequent impact of that role from the perspective of parents can form the basis of better informed clinical practice.

Abstract P3-06-09: Survival among patients with hormone receptor positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer: A real-world observational study

Background: Little is known about real-world outcomes for patients with HR+/HER2- advanced breast cancer. This study examined mortality outcomes, and in particular variations across patients with different stages of cancer and different sequencing of endocrine and chemotherapy treatments.

Methods: This retrospective study linked medical and pharmacy claims (2008-2012) from a large national US health plan with a proprietary clinical cancer database containing physician-reported clinical data on patients with breast cancer. Patients included in the study had HR+ and HER2- status, and had stage III (S3) or IV (S4) cancer at initial diagnosis, or had developed metastases following initial diagnosis (MET). The first date of diagnosis of advanced cancer or the first date of metastases following initial diagnosis was designated as the index date. Health plan enrollment for 3 months pre- and ≥12-months post- index date was required; patients who died within 12 months after index date and were continuously enrolled in the health plan were retained. A 3-month baseline period assessed prior treatment; a variable follow-up (until disenrollment or 31 Oct 2012) assessed patterns of endocrine and chemotherapy treatments following the index date. Patient mortality was identified via a combination of Social Security mortality data and patient hospital discharge status from claims data. Chi-square tests compared proportions and t-tests compared means.

Results: The study population included 263 S3, 71 S4, and 317 MET patients. Average age at index date was 51.9 years for S3, 54.4 years for SIV, and 52.8 years for MET patients (P = 0.080). Over the entire observable follow-up, 3.4% of S3 (17 per 1000 patient-years), 22.5% of S4 (119 per 1000 patient years), and 10.7% of MET patients (22 per 1000 patient years) died (P≤0.010 for comparisons). Mortality over the 1-year after index date was 1.1%, 12.7%, and 5.1% in the S3, S4, and MET groups respectively (P<0.001). Patients who died in the first year after index date survived on average until 5.8 months (S3), 4.5 months (S4), and 7.3 months (MET) following the metastatic index date. Among MET patients, mean time to death from initial breast cancer diagnosis was 35.7 months for MET patients without endocrine treatment prior to chemotherapy (n = 157), and 76.1 months for other MET patients (n = 160) (P = 0.002). For S4 patients without endocrine treatment prior to chemotherapy (n = 34), patients survived an average of 10.0 months from initial advanced breast cancer diagnosis while the remaining S4 patients (n = 37) survived an average of 14.8 months.

Conclusions: Among patients with HR+/HER2- advanced breast cancer, mortality rates varied by stage of disease, and length of survival varied across patients pre-treated with endocrine therapy prior to chemotherapy compared with other patients. Further investigation of drivers behind differences in mortality may reveal the extent to which initial disease severity and sequencing of chemotherapy and endocrine therapy drive these variations.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-09.

Abstract P3-06-08: Patterns of health care utilization and costs by chemotherapy and endocrine therapy sequencing among patients with hormone receptor positive (HR+)/HER2- negative advanced breast cancer

Background: Little is known about health care costs and health services utilization of patients with HR+/HER2- advanced breast cancer, particularly in relation to the order in which patient receive endocrine and chemotherapy treatments.

Methods: A proprietary database with physician-reported clinical data on patients with breast cancer was linked to medical and pharmacy claims (2008-2012) from a national US health plan. Patients included in the study had HR+ and HER2- status. Advanced cancer included stage III or IV (SIV) at initial diagnosis, or developed metastases following initial diagnosis. The first date of advanced cancer diagnosis or date of metastases following initial diagnosis was designated as the index date. Health plan enrollment for 3 months pre- and ≥12-months post- index date was required; patients who died within 12 months after index date and were continuously enrolled were retained. A 3-month baseline period assessed prior treatment; variable follow-up (until disenrollment or 31 Oct 2012) assessed patterns of endocrine and chemotherapy treatments following index date. All-cause and cancer-specific health care utilization and paid costs were assessed over 12-months following index date. Costs were calculated as per-patient-per-month (PPPM), and utilization measured as rates per patient-month. Cancer-related medication costs included drug costs for endocrine, chemotherapy, targeted therapy, and treatments for pain or chemotherapy-induced nausea/ vomiting. In addition, costs for anti-cancer systemic therapies (chemotherapy, endocrine, and targeted therapy) were calculated PPPM including costs for medication administration.

Results: Of 651 study patients, 65% initiated chemotherapy prior to initiating endocrine therapy (CH). Remaining patients (OT) either had no chemotherapy (n = 132 endocrine only, n = 16 neither endocrine nor chemotherapy), or used endocrine therapy prior to chemotherapy (n = 77). Compared with OT, the CH group had more office (4.04 vs. 2.68 visits, P<0.001) and outpatient hospital visits (3.08 vs. 2.10 visits, P<0.001). In addition, 56% of CH vs. 41% of OT had inpatient hospital admissions during the follow-up (P<0.001; rate ratio 0.97, P = NS). Similarly, 60% of CH patients were admitted to emergency rooms vs. 51% of OT (P = 0.033; rate ratio 1.01, P = NS). Mean total all-cause health care costs varied ($11,525 CH vs. $8,196 OT, P<0.001). The largest source of difference in costs were office visits (mean $3,257 CH vs. $1,896 OT, P<0.001), and outpatient hospital ($5,813 CH vs. $3,721 OT, P<0.001). Cancer-related costs comprised the majority of costs (mean $10,249 CH vs. $7,118 OT, P<0.001). The CH group had higher mean cancer-related medication costs than the OT group ($2,051 vs. $1,405 respectively, P = 0.040). Overall mean anti-cancer systemic therapy costs (including administration) were higher in the CH than OT group ($2,934 vs. $1,875, P = 0.012).

Conclusions: Among HR+/HER2- advanced breast cancer patients, health care utilization and costs were higher for patients who initiated chemotherapy prior to endocrine therapy compared to other patients. Further investigation of the drivers behind these differences is warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-08.

Abstract P1-14-03: Chemotherapy and endocrine therapy treatment patterns among patients with hormone receptor positive (HR+)/HER2 negative advanced breast cancer

Background: National Comprehensive Cancer Network breast cancer guidelines suggest optimized sequencing of endocrine therapy prior to chemotherapy use for patients who are HR+/HER2-, but it is unclear how those recommendations translate into clinical practice. This study examined sequencing of endocrine and chemotherapy treatment to better understand real-world treatment patterns for HR+/HER2- advanced breast cancer.

Methods: This retrospective study examined physician-reported clinical data on patients with breast cancer (BC) linked to medical and pharmacy claims (2008-2012) from a large national US health plan. Patients included in the study had HR+ and HER2- status. Advanced cancer cohorts included patients who were stage IV (SIV) at initial diagnosis, or who developed metastases following initial diagnosis (MET). The first date of diagnosis of advanced cancer or date of metastases following initial diagnosis was designated as index date. Health plan enrollment for 3 months pre- and ≥12-months post- index date was required; patients who died within 12 months after index date and were continuously enrolled were retained. A 3-month baseline period assessed prior treatment; variable post-index follow-up (until disenrollment or Oct 2012) assessed patterns of endocrine and chemotherapy.

Results: Of 317 MET patients, 50% initiated chemotherapy after index date without prior endocrine treatment (CH). Remaining patients (OT) used only endocrine therapy (30%), endocrine therapy prior to chemotherapy (17%), or neither endocrine nor chemotherapy (3%). Compared with OT patients, CH patients were younger (50 vs. 55 years, P<0.001) and progressed faster to metastasis after initial BC diagnosis (243 vs. 1633 days, P<0.001). Although CH patients in the MET group had slightly higher comorbidity prior to their metastatic index date, they had lower levels of any non-lymph node metastases (14% vs. 48%, P<0.001) and visceral metastases (5% vs. 16%, P = 0.001) during follow-up. Among MET patients, 92% of CH patients initiated endocrine therapy during follow-up; endocrine therapy started a mean of 235 days after metastatic index date, compared with a mean starting date for chemotherapy of 41 days post-metastatic index date. In the MET group, 55% of CH later initiated treatment with aromatase inhibitors, compared with 64% of OT patients (P = 0.104). Results were similar in newly diagnosed SIV (n = 71) group: 48% had no evidence of endocrine treatment prior to initiating chemotherapy, and remaining patients used only endocrine therapy (27%), had endocrine therapy prior to chemotherapy (21%), or neither therapy (4%).

Conclusions: In this population of patients with HR+/HER2- advanced breast cancer, a large proportion initiated chemotherapy without prior endocrine therapy. This group of patients might otherwise benefit from a longer progression free period with tolerable toxicity from endocrine therapy. Further investigation of whether a subgroup of these patients started chemotherapy in the adjuvant setting is warranted. For those starting chemotherapy without prior endocrine therapy, understanding treatment sequencing and patient characteristics will help illuminate the extent to which patterns adhere to NCCN guidelines.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-14-03.

Case definitions, diagnostic algorithms, and priorities in encephalitis: consensus statement of the international encephalitis consortium

BACKGROUND

Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research.

METHODS

In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study.

RESULTS

We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed.

CONCLUSIONS

We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

Effects of elevated atmospheric CO2 on competition between the mosquitoes Aedes albopictus and Ae. triseriatus via changes in litter quality and production

Elevated atmospheric CO2 can alter aquatic communities via changes in allochthonous litter inputs. We tested effects of atmospheric CO2 on the invasive Aedes albopictus (Skuse) and native Aedes triseriatus (Say) (Diptera: Culicidae) via changes in competition for microbial food or resource inhibition/toxicity. Quercus alba L. litter was produced under elevated (879 ppm) and ambient (388 ppm) atmospheric CO2. Saplings grown at elevated CO2 produced greater litter biomass, which decayed faster and leached more tannins than saplings at ambient CO2. Competition was tested by raising larvae in different species and density combinations provisioned with elevated- or ambient-CO2 litter. Species-specific performance to water conditions was tested by providing single-species larval cohorts with increasing amounts of elevated- or ambient-CO2 litter, or increasing concentrations of tannic acid. Larval densities affected some fitness parameters of Ae. albopictus and Ae. triseriatus, but elevated-CO2 litter did not modify the effects of competition on population growth rates or any fitness parameters. Population growth rates and survival of each species generally were affected negatively by increasing amounts of both elevated- and ambient-CO2 litter from 0.252 to 2.016 g/liter, and tannic acid concentrations above 100 mg/liter were entirely lethal to both species. Aedes albopictus had consistently higher population growth rates than Ae. triseriatus. These results suggest that changes to litter production and chemistry from elevated CO2 are unlikely to affect the competitive outcome between Ae. albopictus and Ae. triseriatus, but that moderate increases in litter production increase population growth rates of both species until a threshold is exceeded that results in resource inhibition and toxicity.

Local gene delivery of heme oxygenase-1 by adeno-associated virus into osteoarthritic mouse joints exhibiting synovial oxidative stress

OBJECTIVE

To evaluate the role of synovial oxidative stress on joint pathology in a spontaneous mouse model of osteoarthritis (OA) by intra-articular (IA) delivery of recombinant adeno-associated virus (rAAV) expressing anti-oxidant protein heme oxygenase-1 (HO-1).

METHODS

Joint transduction by rAAV vectors was evaluated with serotype 1, 2, 5 and 8 capsids carrying LacZ gene administered by IA injections into STR/ort mice. Transduced cell types were identified by β-galactosidase staining in sectioned joints. Effect of oxidative stress on AAV transduction of primary synoviocytes in vitro was quantitated by fluorescence-activated cell sorting (FACS) analysis. In vivo, the efficacy of rAAV1/HO-1 was tested by IA administration into STR/ort mice followed by histopathological scoring of cartilage. Levels of 3-nitrotyrosine (3-NT) and HO-1 were assessed by immunohistochemistry (IHC) of joint sections.

RESULTS

Administration of a rAAV1 based vector into OA mouse joints resulted in transduction of the synovium, joint capsule, adipocytes and skeletal muscle while none of the serotypes showed significant cartilage transduction. All OA joints exhibited significantly elevated levels of oxidative stress marker, 3-NT, in the synovium compared to OA-resistant CBA-strain of mice. In vitro studies demonstrated that AAV transgene expression in primary synoviocytes was augmented by oxidative stress induced by H(2)O(2) and that a rAAV expressing HO-1 reduced the levels of oxidative stress. In vivo, HO-1 was increased in the synovium of STR/ort mice. However, delivery of rAAV1/HO-1 into OA joints did not reduce cartilage degradation.

CONCLUSIONS

AAV-mediated HO-1 delivery into OA joints during active disease was not sufficient to improve cartilage pathology in this model.

Abstract 611: Damage-associated Molecular Pattern (DAMP) Signaling Contributes to Poor Outcomes in Diabetic Ischemic Stroke

Aims: Vascular injury including edema and hemorrhage after ischemic stroke is increased in diabetes. High-mobility group box 1 (HMGB1) is a DAMP passively released by necrotic cells that initiates pro-inflammatory signaling through binding to the TLR4 receptor. Here, we investigated the possible involvement of HMGB1 in increased vascular damage in diabetic ischemic stroke.

Methods and Results: Focal ischemia was induced by 3 h MCAO and 21 h reperfusion in sham (n=6), (Wistar, n=5-7) or diabetic (Goto-Kakizaki, n=6) rats. Expression of HMGB1 and TLR4 was assessed by Western blot in both ischemic and non-ischemic hemispheres. Compared to sham, both control and diabetic rats showed a 2-fold increase in HMGB1 in both non-ischemic and ischemic hemispheres, respectively. While there was no change in TLR4 expression in control rats, it was increased by 2-fold in both hemispheres in diabetes. Neurovascular injury as indicated by percent (%) infarct, edema ratio (edema/infarct), incidence of hematoma and functional outcome were assessed in all groups. Infarct was greater in controls (57.7±5.8% vs. 23±1.0%), while edema ratio was greater in diabetic animals (1.8±0.2 vs. 0.2±0.06). Hematoma was present in the ischemic hemispheres of all diabetic rats and in 43% of the controls. Compared to controls, neurological deficits were greater in diabetic animals after focal ischemia (p<0.05).

Conclusions and clinical relevance: Our findings indicate that HMGB1 and TLR4 may be involved in augmented vascular injury in diabetic ischemic stroke. As such, better understanding of the role(s) of DAMPs including HMGB1 and TLR4 will aid in the development of vasculoprotective therapeutic strategies and improve outcomes for diabetic stroke patients.

An international round-robin calibration protocol for nanoindentation measurements

Nanoindentation has become a common technique for measuring the hardness and elastic-plastic properties of materials, including coatings and thin films. In recent years, different nanoindenter instruments have been commercialised and used for this purpose. Each instrument is equipped with its own analysis software for the derivation of the hardness and reduced Young's modulus from the raw data. These data are mostly analysed through the Oliver and Pharr method. In all cases, the calibration of compliance and area function is mandatory. The present work illustrates and describes a calibration procedure and an approach to raw data analysis carried out for six different nanoindentation instruments through several round-robin experiments. Three different indenters were used, Berkovich, cube corner, spherical, and three standardised reference samples were chosen, hard fused quartz, soft polycarbonate, and sapphire. It was clearly shown that the use of these common procedures consistently limited the hardness and reduced the Young's modulus data spread compared to the same measurements performed using instrument-specific procedures. The following recommendations for nanoindentation calibration must be followed: (a) use only sharp indenters, (b) set an upper cut-off value for the penetration depth below which measurements must be considered unreliable, (c) perform nanoindentation measurements with limited thermal drift, (d) ensure that the load-displacement curves are as smooth as possible, (e) perform stiffness measurements specific to each instrument/indenter couple, (f) use Fq and Sa as calibration reference samples for stiffness and area function determination, (g) use a function, rather than a single value, for the stiffness and (h) adopt a unique protocol and software for raw data analysis in order to limit the data spread related to the instruments (i.e. the level of drift or noise, defects of a given probe) and to make the H and E(r) data intercomparable.

A Percutaneous Technique for Reduction and Internal Fixation of Displaced Intra-Articular Calcaneal Fractures

Introduction

A retrospective cohort study demonstrated that, in comparison with open reduction and internal fixation through an extensile lateral approach, our percutaneous technique for reduction and internal fixation of displaced intra-articular calcaneal fractures decreases the rate of complications and achieves and maintains extra-articular fracture reductions just as well.

Step 1 Patient Positioning and Imaging

Position the patient correctly to obtain excellent fluoroscopic views, which are key to the procedure.

Step 2 Fracture Reduction

The techniques for reducing and fixing joint depression and tongue-type calcaneal fractures differ and will be described separately.

Step 3 Screw Fixation

Identify screw entry points and paths using fluoroscopic images, and confirm the final positions with c-arm imaging.

Step 4 Postoperative Management

Apply a splint; then obtain postoperative images to confirm fracture reduction and screw placement.

Results & Preop/Postop Images

The results of percutaneous reduction of displaced intra-articular calcaneal fractures in seventy-nine patients with a total of eighty-three fractures were compared with those obtained by another surgeon using the extensile lateral approach.

What to Watch For

IndicationsContraindicationsPitfalls & Challenges.

Lack of pneumococcal carriage in the hospitalised elderly

There have been few surveys of Streptococcus pneumoniae and Neisseria meningitidis carriage in sick or frail elderly people who, with the very young, comprise the group who are at highest risk for pneumococcal disease. We studied pneumococcal carriage among participants in a pneumococcal immunisation study in the frail elderly.

METHODS

Subjects aged >or=60 years were recruited from a large tertiary referral hospital in Sydney, Australia. Nose and throat swabs were collected at the time of enrolment and 12 months after immunisation.

RESULTS

Before immunisation, only 1 of 315 participants was identified as a nasal carrier of S. pneumoniae; another was identified as throat carrier of N. meningitidis. None of the participants examined after immunisation was carrying either S. pneumoniae or N. meningitidis.

CONCLUSION

The low rate of pneumococcal carriage in this population of hospitalised elderly patients was unexpected. The most likely reason is that long-term carriage is rare in this population and suggests that pneumococcal disease primarily follows recent acquisition of S. pneumoniae types not associated with carriage.