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.

Different responses to reward comparisons by three primate species

BACKGROUND

Recently, much attention has been paid to the role of cooperative breeding in the evolution of behavior. In many measures, cooperative breeders are more prosocial than non-cooperatively breeding species, including being more likely to actively share food. This is hypothesized to be due to selective pressures specific to the interdependency characteristic of cooperatively breeding species. Given the high costs of finding a new mate, it has been proposed that cooperative breeders, unlike primates that cooperate in other contexts, should not respond negatively to unequal outcomes between themselves and their partner. However, in this context such pressures may extend beyond cooperative breeders to other species with pair-bonding and bi-parental care.

METHODS

Here we test the response of two New World primate species with different parental strategies to unequal outcomes in both individual and social contrast conditions. One species tested was a cooperative breeder (Callithrix spp.) and the second practiced bi-parental care (Aotus spp.). Additionally, to verify our procedure, we tested a third confamilial species that shows no such interdependence but does respond to individual (but not social) contrast (Saimiri spp.). We tested all three genera using an established inequity paradigm in which individuals in a pair took turns to gain rewards that sometimes differed from those of their partners.

CONCLUSIONS

None of the three species tested responded negatively to inequitable outcomes in this experimental context. Importantly, the Saimiri spp responded to individual contrast, as in earlier studies, validating our procedure. When these data are considered in relation to previous studies investigating responses to inequity in primates, they indicate that one aspect of cooperative breeding, pair-bonding or bi-parental care, may influence the evolution of these behaviors. These results emphasize the need to study a variety of species to gain insight in to how decision-making may vary across social structures.

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.

Public knowledge of and attitudes toward genetics and genetic testing

BACKGROUND

Variable health literacy and genetic knowledge may pose significant challenges to engaging the general public in personal genomics, specifically with respect to promoting risk comprehension and healthy behaviors.

METHODS

We are conducting a multistage study of individual responses to genomic risk information for Type 2 diabetes mellitus. A total of 300 individuals were recruited from the general public in Durham, North Carolina: 60% self-identified as White; 70% female; and 65% have a college degree. As part of the baseline survey, we assessed genetic knowledge and attitudes toward genetic testing.

RESULTS

Scores of factual knowledge of genetics ranged from 50% to 100% (average=84%), with significant differences in relation to racial groups, the education level, and age. Scores were significantly higher on questions pertaining to the inheritance and causes of disease (mean score 90%) compared to scientific questions (mean score 77.4%). Scores on the knowledge survey were significantly higher than scores from European populations. Participants' perceived knowledge of the social consequences of genetic testing was significantly lower than their perceived knowledge of the medical uses of testing. More than half agreed with the statement that testing may affect a person's ability to obtain health insurance (51.3%) and 16% were worried about the consequences of testing for chances of finding a job.

CONCLUSIONS

Despite the relatively high educational status and genetic knowledge of the study population, we find an imbalance of knowledge between scientific and medical concepts related to genetics as well as between the medical applications and societal consequences of testing, suggesting that more effort is needed to present the benefits, risks, and limitations of genetic testing, particularly, at the social and personal levels, to ensure informed decision making.

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.