CAD/CAM Polymer vs Direct Composite Resin Core Buildups for Endodontically Treated Molars Without Ferrule

OBJECTIVES

The aim of this study was to investigate the restoration of broken-down endodontically treated molars without ferrule effect using glass ceramic crowns on different composite resin core buildups.

METHODS AND MATERIALS

Forty-five decoronated endodontically treated teeth (no ferrule) were restored with a semidirect buildup using an experimental computer-aided design/computer-aided manufacturing (CAD/CAM) high-performance polymer (HPP group) or with light-curing composite core buildups of Tetric EvoCeram with (TECP group) or without (TEC group) a glass-fiber-reinforced post. All teeth were prepared to receive bonded glass ceramic crowns (Empress CAD luted with Variolink II) and were subjected to accelerated fatigue testing. Cyclic isometric loading was applied to the palatal cusp at an angle of 30° and a frequency of 5 Hz, beginning with a load of 200 N (×5000 cycles) and followed by stages of 400, 600, 800, 1000, 1200, and 1400 N at a maximum of 30,000 cycles each. Specimens were loaded until failure or to a maximum of 185,000 cycles. Groups were compared using the life-table survival analysis (log rank test at p=0.05). Average fracture loads and number of survived cycles were compared with one-way analysis of variance (Scheffé post hoc at p=0.05).

RESULTS

None of the tested specimen withstood all 185,000 load cycles. There was a significant difference in mean fracture load, survived cycles, and survival; the HPP group (fracture load 975.27N±182.74) was significantly higher than the TEC (716.87N±133.43; p=0.001) and TECP (745.67±156.34; p=0.001) groups, and the TEC and TECP groups showed no difference (p=0.884). Specimens in the TECP group were affected by an initial failure phenomenon (wide gap at the margin between the buildup/crown assembly and the root).

CONCLUSIONS

Semidirect core buildup made from high-performance polymer enhanced the performance of all-ceramic leucite-reinforced glass ceramic crowns compared with direct light-curing composite resin buildups. The use of a fiber-reinforced post system did not influence the fatigue strength of all-ceramic crowns.

Weightlifter's Nodule: A New Variant of Athlete's Nodule

A 17-year-old high school football player presented to our dermatology clinic complaining of two asymptomatic lumps on the upper part of his back. The first lump was noticed on the right side of the upper aspect of his back following a weightlifting session. The second lump appeared on the left side of the upper part of his back several weeks later. The patient's personal and family medical history was unremarkable. Physical examination revealed an ill-defined, firm, mobile subcutaneous nodule measuring approximately 3 cm on the right upper part of the back and a similar but smaller nodule on the left upper portion of the back (Figure 1). The location of the lesions corresponded to the areas of maximal pressure produced by a squat bar that he uses frequently during weightlifting (Figure 2). Histologic analysis of the right lesion revealed a markedly expanded dermis caused by a striking increase in the number of collagen bundles that were relatively normal in thickness, accompanied by a subtle increase in the number of fibroblasts (Figure 3). In some foci, fibroplasia along with increased deposition of mucin further contributed to the expansion of the dermis (Figure 3). Although the process spanned the entire dermis, it was more pronounced in the deep reticular dermis, particularly near the subcutis as collagen bundles were arranged in a more haphazard array in this region. Verhoeff-Van Gieson stain revealed diminished and fragmented elastic fibers within some of the involved areas. This reactive fibrosis can be seen in athlete's nodules as a result of repetitive blunt pressure. We proposed a diagnosis of weightlifter's nodule to further classify these lesions and the patient was instructed to discontinue associated weightlifting activities.

Nuchal Translucency Quality Review (NTQR) program: first one and half million results

OBJECTIVE

To evaluate the performance of first-trimester nuchal translucency (NT) measurement by providers (physician-sonologists and sonographers) within the Nuchal Translucency Quality Review (NTQR) program.

METHODS

After training and credentialing providers, the NTQR monitored performance of NT measurement by the extent to which an individual's median multiple of the normal median (MoM) for crown-rump length (CRL) was within the range 0.9-1.1 MoM of a published normal median curve. The SD of log10 MoM and regression slope of NT on CRL were also evaluated. We report the distribution between providers of these performance indicators and evaluate potential sources of variation.

RESULTS

Among the first 1.5 million scans in the NTQR program, performed between 2005 and 2011, there were 1 485 944 with CRL in the range 41-84 mm, from 4710 providers at 2150 ultrasound units. Among the 3463 providers with at least 30 scans in total, the median of the providers' median NT-MoMs was 0.913. Only 1901 (55%) had a median NT-MoM within the expected range; there were 89 above 1.1 MoM, 1046 at 0.8-0.9 MoM, 344 at 0.7-0.8 MoM and 83 below 0.7 MoM. There was a small increase in the median NT-MoM according to providers' length of time in the NTQR program and number of scans entered annually. On average, physician-sonologists had a higher median NT-MoM than did sonographers, as did those already credentialed before joining the program. The median provider SD was 0.093 and the median slope was 13.5%. SD correlated negatively with the median NT-MoM (r = -0.34) and positively with the slope (r = 0.22).

CONCLUSION

Even with extensive training, credentialing and monitoring, there remains considerable variability between NT providers. There was a general tendency towards under-measurement of NT compared with expected values, although more experienced providers had performance closer to that expected.

Abstract OT2-1-02: Novel combination of toll-like receptor (TLR)-7 agonist imiquimod and local radiotherapy in the treatment of breast cancer chest wall recurrences or skin metastases

Background/Rationale: To assess the immune and systemic anti-tumor effects of the novel combination of local radiotherapy combined with imiquimod applied topically to breast cancer metastatic to skin. Breast cancer is the most common tumor, excluding melanoma, to metastasize to the skin in women. Chest wall recurrence is debilitating for patients, substantially affecting quality of life. Current treatment modalities for unresectable lesions are rarely curative and patients ultimately die of visceral metastases, indicating the need for more effective therapies. Imiquimod (IMQ), a synthetic TLR-7 agonist has immunomodulatory activity with profound effects on the tumor environment and can lead to tumor regression of cutaneous breast cancer metastases (Adams et al, Clin Ca Res, Dec 15, 2012). Accumulating evidence indicates that the potential of local radiotherapy to convert the tumor into an in-situ vaccine can be enhanced by combination with immunotherapy to achieve a therapeutic synergy. We have previously shown in a mouse model of cutaneous breast cancer that topical IMQ synergizes with local RT to induce complete tumor regression (REF). Importantly, this approach used a local treatment to generate anti-tumor immune responses with ability to control the tumor systemically (Dewan et al, Clin Ca Res Dec 15, 2012). This trial was designed to test the feasibility of translating this therapeutic synergy in the clinic (clinicaltrials.gov NCT01421017).

Methods: Eligibility includes patients with biopsy-confirmed breast cancer, measurable disease and skin metastases, ECOG PS 0-2 and adequate organ/marrow function. Radiation therapy is delivered to one area of skin metastases in five fractions of 6 Gy (days 1,3,5,8,10). IMQ 5% cream is applied topically to skin metastases overnight for 5 days/week for 8 weeks, beginning the evening of the first radiotherapy. Continuous imiquimod to all skin metastases even after completion of RT is based on our preclinical evidence of an improved effector phase of the immune response. Additional treatment cycles with IMQ/RT are permitted. Following a brief phase I portion to allow dose optimization in the event of unanticipated adverse events (3-3 design), the phase II study evaluates efficacy with a planned additional 25 patients. Primary endpoint is the response rate in untreated metastases, assessed by immune-related response criteria. Furthermore, the local tumor responses and safety of the combination will be determined; tumor FNA biopsies will be obtained to investigate signatures of immune-mediated rejection as recently described with IMQ mediated rejection of basal cell carcinomas; and peripheral lymphocytes will be examined for the induction/boosting of selected tumor antigen-specific T and B cell responses.

The phase I portion has been successfully completed with 6 patients without DLT. Enrollment into the phase II portion has begun. At present, a total of 11 patients have been enrolled.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-1-02.

Abstract P2-10-05: Lymphatic and pro-inflammatory candidate gene variations and breast-cancer related lymphedema

Background

Traditionally, breast cancer-related lymphedema is considered to be mainly due to the mechanical injury from cancer surgery. Recent research identified that inflammation-infection may be one of the important predictors for breast cancer-related lymphedema. This pilot study aimed to explore the associations between lymphatic and pro-inflammatory candidate gene variations and lymphedema following breast cancer treatment.

Methods

A prospective, longitudinal, repeated-measure, and comparative design was used to recruit a sample of 178 breast cancer survivors. To ensure the accuracy of lymphedema phenotype, lymphedema was classified into two phenotypes: lymphedema of arm and breast. Arm lymphedema refers to swelling in the affected arm that must have been validated by infra-red perometer-S350 and a bioimpedance device. Breast lymphedema refers to swelling in the affected breast validated by self-report and an observational scale since no objective measure is available.

Saliva samples were collected for DNA extraction from all the 178 participants. Candidate Gene Association Research Method was used to examine the eight genes known for inflammation and lymphatic specific growth factors, including candidate genes for inflammation, cytokines (IL1A, IL6, IL8, IL10, IL13) and PTGS2 (COX2), and lymphatic specific growth factors [VEGF-C & D]. Descriptive statistics, Chi-Squared tests for contingency tables and one-way analysis of variance for continuous variables were used to compare the genotypes for each of these genes in patients with and without lymphedema. Odds ratios of developing lymphedema are estimated.

Results

Among 178 survivors, 39 women were confirmed to have arm lymphedema by infra-red perometer-S350 and a bioimpedance device and 43 women had breast lymphedema. Five genes were significantly associated with breast cancer-related lymphedema. Specific single nucleic polymorphisms (SNPs) for lymphatic specific growth factors VEGF-C (rs4604006) and cytokine IL13 (rs1800925) were related to arm lymphedema. Specific SNPs of cytokine IL1A (rs1800587) and PTGS2 (COX2) (rs20417) were associated with breast lymphedema.

Conclusion

Our findings provided preliminary data on genetic susceptibility as a risk factor for breast cancer-related lymphedema. Findings of our study may serve as a preliminary foundation for a priori recognition of genetic risk that may facilitate lymphedema risk prediction prior to surgery and raises the potential for early intervention for a high-risk group.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-10-05.

Cell-cycle characteristics - alterable determinants of remission duration in a study of 179 standard risk newly diagnosed patients with acute myeloid-leukemia

Prognostic factors were related to remission duration among 179 standard risk newly diagnosed acute myeloid leukemia (AML) patients who received identical induction and consolidation therapies. Following a bromodeoxyuridine infusion, labeling indices of bone marrow aspirate/biopsy, durations of S-phase and cell cycle (Tc) were determined. Patients with slowly cycling myeloblasts had longer remissions (Log rank p=0.03) than those with rapidly cycling myeloblasts. Multivariate analysis demonstrated that both WBC and Tc contributed to remission duration (p=0.01 and 0.005 respectively). Patients with slowly proliferating leukemias have longer remissions probably due to slower regrowth of leukemia between chemotherapy courses.

Behavioral dynamics and neural grounding of a dynamic field theory of multi-object tracking

The ability to dynamically track moving objects in the environment is crucial for efficient interaction with the local surrounds. Here, we examined this ability in the context of the multi-object tracking (MOT) task. Several theories have been proposed to explain how people track moving objects; however, only one of these previous theories is implemented in a real-time process model, and there has been no direct contact between theories of object tracking and the growing neural literature using ERPs and fMRI. Here, we present a neural process model of object tracking that builds from a Dynamic Field Theory of spatial cognition. Simulations reveal that our dynamic field model captures recent behavioral data examining the impact of speed and tracking duration on MOT performance. Moreover, we show that the same model with the same trajectories and parameters can shed light on recent ERP results probing how people distribute attentional resources to targets vs. distractors. We conclude by comparing this new theory of object tracking to other recent accounts, and discuss how the neural grounding of the theory might be effectively explored in future work.

Search for charged Higgs bosons in e+e- collisions at [Formula: see text]

A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at [Formula: see text], corresponding to an integrated luminosity of approximately 600 pb-1. Charged Higgs bosons are assumed to be pair-produced and to decay into [Formula: see text], τντ or AW±. No signal is observed. Model-independent limits on the charged Higgs-boson production cross section are derived by combining these results with previous searches at lower energies. Under the assumption [Formula: see text], motivated by general 2HDM type II models, excluded areas on the [Formula: see text] plane are presented and charged Higgs bosons are excluded up to a mass of 76.3 GeV at 95 % confidence level, independent of the branching ratio BR(H±→τντ ). A scan of the 2HDM type I model parameter space is performed and limits on the Higgs-boson masses [Formula: see text] and mA are presented for different choices of tanβ.

P1-17-07: Phase II Trial of RAD001 Plus Carboplatin in Patients with Triple-Negative Metastatic Breast Cancer

Background: RAD001 is an oral mTOR inhibitor that has exhibited activity in breast cancer. Triple negative breast cancer cells are unable to repair double stranded DNA breaks and hence have sensitivity to platinum agents that cause interstrand cross-links. Rapamycin acts synergistically with platinum agents to induce apoptosis and inhibit proliferation in at least two different breast cancer cell lines (including ER/PR negative cell lines). We propose that combination RAD001 and carboplatin may have activity in triple-negative breast cancer.

Methods: The primary objective of the study is to determine clinical benefit (complete remission (CR) + partial remission (PR) + stable disease (SD)) and the toxicity of this combination in women with triple negative metastatic breast cancer who have had 0–3 prior chemotherapy regimens for metastatic disease. Secondary objectives are to determine progression free survival as well as investigating the relationship between pretreatment sensitivity (biopsy at baseline) and clinical response (biopsy post 2 cycles) using IHC staining for abundance of key proteins in the Akt-mTOR pathway and their activity using surrogate phosphorylation site-specific antibodies (Akt and phospho-serine 473, phospho-threonine and phospho-threonine 308 Akt; mTOR and phospho-serine 2448 mTOR; ribosome protein S6 kinase (S6K) and phospho-threonine 378 S6K; 4E-BP1 and phospho-serine 65 4E-BP1). Prior carboplatin is allowed. Women with treated brain metastasis are eligible. According to the original study plan, carboplatin AUC 6, was to be given intravenously every three weeks. Five mg of RAD001 was to be given daily with a 3 patient run-in and then 10 mg daily if there were no dose-limiting toxicities. Due to a unexpected amount of thrombocytopenia with this combination the dose of carboplatin was first amended to AUC 5 and most recently to AUC 4 with 5 mg of RAD001 (and no plan to escalate to 10 mg).

Results: Fourteen patients of a planned 25 have been recruited thus far. Median age is 58.5. Median number of prior regimens is 2 (0-3). Of the 7 patients assessable for response at this time, there have been 2 PR's and 5 patients with SD. One SD was achieved in a patient progressing on single agent carboplatin at study entry. Median duration of SD + PR is 28.5 weeks (5 patients have ongoing response ranging from 8–46.5 weeks). Five of 8 patients assessable for toxicity had grade 3 or 4 thrombocytopenia and 2 patients had grade 3 neutropenia. No cases of febrile neutropenia were observed. Four patients have required blood transfusion and one patient has required platelet transfusion. All patients have had treatment held and/or dose reductions secondary to hematological toxicity, however, since amended carboplatin dose the regimen has been very well tolerated with only one out of six patients) with grade 3 neutropenia and grade 3 thrombocytopenia. There have been no non-hematological grade 3 or 4 toxicities.

Conclusions: Clinical benefit was observed in all 7 assessable patients. Dose limiting thrombocytopenia was an unexpected side effect requiring protocol amendment. We continue to accrue study subjects at the amended dosing.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-17-07.

Impact of HER2 Status on Risk of Sentinel Node Metastasis: An Independently Validated Multivariable Model

Purpose The presence of axillary lymph node metastases is dictated by tumor biology and is a strong prognostic indicator in breast cancer. We have previously published a user-friendly nomogram that provides a risk estimate for sentinel lymph node (SLN) metastasis in women with breast cancer (Bevilacqua et al. 2007, J Clin Oncol 25: 3670). At that time, HER2 testing was not uniformly performed, but is now standard of care. The purpose of this study was to determine if the addition of HER2 status or grouping of patients by molecular subtype improves the prediction of SLN metastasis.Patients and Methods: The ability of clinical and pathologic features to predict the presence of SLN metastasis in patients presenting with clinically node negative invasive breast cancer, was assessed with multivariable logistic regression (MVA) for 4723 sequential SLN biopsy procedures with known ER, PR, and HER2 from 1996 to 2004. HER2 status was defined as positive if IHC=3+ and/or FISH≥2. The modeling (n=3297) and validation (n=1426) groups were identified by simple random sampling. Two models were created using the modeling population: one included ER, PR, and HER2 as separate variables and one combined these markers into 4 subtypes defined as: Luminal A-like=ER or PR +, HER2 −; Luminal B-like=ER or PR +, HER2 +; HER2-like=ER and PR −, HER2 +; Basal-like=ER and PR −, HER2 −. The validation group was used to assess the calibration (intercept, slope, Emax, Eavg) and discrimination (AUC, area under the receiver operating curve) of the models.Results: In addition to age, tumor size, tumor type, lymphovascular invasion, tumor location, and multifocality, subtype was found to be an independent predictor of SLN metastasis on MVA (p=0.003). The Basal-like subtype was associated with a significantly lower risk of SLN metastasis (compared with referent Luminal A-like subtype, OR=0.58). HER2 alone was not found to be an independent predictor of SLN metastasis (p=0.56), while ER and PR remained significant (p=.05, p=.02). Compared to our previous model without HER2, the AUC was slightly decreased by the addition of either HER2 or subtype into the model, but the calibration was slightly improved (Table 1). DiscriminationCalibrationModelAUCInterceptSlopeEmaxEavgPrevious Model0.735- 0.0440.8690.0390.020Mew model with HER20.733- 0.0030.8890.0270.019New model with subtype0.731- 0.0010.8870.0270.020Table 1: Discrimination and calibration measures comparing the new model (with HER2 alone or subtype) with the previously published model (without HER2 or subtype).Conclusion: The addition of subtype, defined by combining HER2 status with ER and PR, slightly increases the calibration of the new model but does not increase its discrimination compared to the previous model. Breast tumor subtype is a significant independent predictor of risk of SLN metastasis, with basal-like subtype having a lower risk of SLN metastasis.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1004.

Depressive relapse during lithium treatment associated with increased serum thyroid-stimulating hormone: results from two placebo-controlled bipolar I maintenance studies

OBJECTIVE

To assess the relationship between depressive relapse and change in thyroid function in an exploratory post hoc analysis from a controlled maintenance evaluation of bipolar I disorder.

METHOD

Mean thyroid-stimulating hormone (TSH) and outcome data were pooled from two 18-month, double-blind, placebo-controlled, maintenance studies of lamotrigine and lithium monotherapy. A post hoc analysis of 109 subjects (n = 55 lamotrigine, n = 32 lithium, n = 22 placebo) with serum TSH values at screening and either week 52 (+/-14 days) or study drop-out was conducted.

RESULTS

Lithium-treated subjects who required an intervention for a depressive episode had a significantly higher adjusted mean TSH level (4.4 microIU/ml) compared with lithium-treated subjects who did not require intervention for a depressive episode (2.4 microIU/ml).

CONCLUSION

Lithium-related changes in thyroid function are clinically relevant and should be carefully monitored in the maintenance phase of bipolar disorder to maximize mood stability and minimize the risk of subsyndromal or syndromal depressive relapse.

Preliminary results from a phase II study of ARQ 197 in patients with microphthalmia transcription factor family (MiT)-associated tumors

10502

Background: ARQ 197 is a selective, non-ATP competitive inhibitor of c-Met, a receptor tyrosine kinase implicated in tumor cell migration, invasion, and proliferation. The drug has demonstrated a favorable safety profile and preliminary anti-cancer activity in three phase 1 studies. MiT tumors include clear cell sarcoma (CCS), alveolar soft part sarcoma (ASPS), and translocation-associated renal cell carcinoma (TLA RCC) and are linked biologically by a shared activated transcriptional mechanism which directly upregulates c-Met. Tumors with this type of chromosomal abnormality are generally resistant to all approved therapies and, in the absence of complete surgical resection, prove invariably fatal. Methods: This is a multi-center, single arm, two-stage phase 2 trial in patients (pts) 13 years of age or older with MiT tumors. Initially pts received 120 mg ARQ 197 orally twice daily (bid). The protocol was amended in August 2008 to increase the dose to 360 mg bid. If either a complete response (CR) or a partial response (PR) were to be observed in the 23 pts in stage 1, the study would be advanced to stage 2 where 16 additional patients will be enrolled. Tumor responses are measured in 8-week intervals per RECIST criteria. Results: To date, 28 pts (19 females, 9 males; median age = 21; 7 CCS, 17 ASPS, 4 RCC) have been treated. One pt with CCS demonstrated a confirmed PR, 15 pts (10 ASPS, 2 CCS, 3 RCC) demonstrated stable disease (SD) for durations up to 29+ weeks, and 4 pts progressed. An overall response rate of 5% and a disease control rate (CR+PR+SD) of 80% were demonstrated among 20 pts who were evaluable for efficacy. The most common drug-related adverse events (AEs) have been fatigue (35.7%), nausea (35.7%), vomiting (21.4%), decreased hemoglobin (10.7%). and cough (10.7%). To date, only 3 drug-related Grade 3 or 4 AEs have been reported including anemia (2) and decreased neutrophil count (1). No drug-related serious AEs or deaths have been reported. Conclusions: To date, ARQ 197 has demonstrated an extremely favorable safety profile and preliminary evidence of anti-cancer activity in these young pts. The criterion for advancing the study from stage 1 to stage 2 has been met. Stage 2 enrollment is ongoing. Updated data on both dose levels will be presented.

[Table: see text]

Study of quadrant high-dose intraoperative radiation therapy for early-stage breast cancer

BACKGROUND

Partial breast irradiation has been tested in limited pilot studies and shown to provide acceptable cosmesis, minimal toxicity and adequate local control. The aim of this study was to determine the feasibility of using quadrant high-dose intraoperative radiation therapy (IORT) for the treatment of early-stage breast cancer.

METHODS

Fifty-two women with early-stage breast cancer were treated with breast-conserving therapy and IORT between October 2002 and January 2006. The first 18 women received a radiation dose of 20 Gy. The protocol was then amended and the remaining 34 women were treated with 18 Gy. Each patient was evaluated after surgery, and at 3, 6 and 12 months; complications, toxicity and cosmetic outcomes were recorded by the breast surgeon.

RESULTS

Women treated with 18 Gy appeared to have a more favourable cosmetic outcome compared with the earlier treatment group. At last follow-up, none of the women treated on the protocol had a breast recurrence.

CONCLUSION

Experience suggests that this IORT technique is feasible, although further follow-up is necessary to assess its therapeutic value.

Banff schema for grading pancreas allograft rejection: working proposal by a multi-disciplinary international consensus panel

Accurate diagnosis and grading of rejection and other pathological processes are of paramount importance to guide therapeutic interventions in patients with pancreas allograft dysfunction. A multi-disciplinary panel of pathologists, surgeons and nephrologists was convened for the purpose of developing a consensus document delineating the histopathological features for diagnosis and grading of rejection in pancreas transplant biopsies. Based on the available published data and the collective experience, criteria for the diagnosis of acute cell-mediated allograft rejection (ACMR) were established. Three severity grades (I/mild, II/moderate and III/severe) were defined based on lesions known to be more or less responsive to treatment and associated with better- or worse-graft outcomes, respectively. The features of chronic rejection/graft sclerosis were reassessed, and three histological stages were established. Tentative criteria for the diagnosis of antibody-mediated rejection were also characterized, in anticipation of future studies that ought to provide more information on this process. Criteria for needle core biopsy adequacy and guidelines for pathology reporting were also defined. The availability of a simple, reproducible, clinically relevant and internationally accepted schema for grading rejection should improve the level of diagnostic accuracy and facilitate communication between all parties involved in the care of pancreas transplant recipients.

Symptoms of depression and cognitive functioning in older American Indians

Depression and lower cognitive functioning are common conditions in older populations. While links between psychopathology and neuropsychological performance have been studied in the white majority population, little is known about such links in the American Indian population. American Indians aged 60 and older (n=140) completed structured interviews that included a depression screener and two cognitive screening measures, the Mini-Mental State Examination (MMSE) and the Mattis Dementia Rating Scale (MDRS). Participants had mean values of 26.7/30 on the MMSE and 125.8/144 on the MDRS. The depression screen was not associated with the MMSE or MDRS total scores. However, older American Indians who screened positive for depression scored lower than did those American Indians who screened negatively for depression (27.7 versus 29.8 respectively) on the MDRS conceptualization subscale after adjusting for sociodemographic and health variables. The combined effects of psychopathology and cognitive impairment are likely to adversely impact the health and welfare of American Indians and their families. More research is needed to provide a better understanding of the relationship between psychopathology and cognition that will help inform clinical treatment for psychopathology in older ethnic minorities.

Heritability of flow-mediated dilation: a twin study

BACKGROUND

Endothelial dysfunction assessed by brachial artery flow-mediated dilation (FMD) is a marker for early atherosclerotic vascular disease and future cardiovascular events.

OBJECTIVE

To estimate the heritability of brachial artery FMD using a twin design.

METHODS

We estimated the heritability of FMD using 94 middle-aged male twin pairs. FMD was measured by ultrasound, and traditional coronary heart disease risk factors were measured. Genetic modeling techniques were used to determine the relative contributions of genes and environment to the variation in FMD.

RESULTS

The mean age of the twin participants was 54.9 +/- 2.8 years. The mean FMD was 0.047 +/- 0.030. The intraclass correlation coefficient was higher in MZ twins [0.38, 95% confidence interval (CI) 0.32-0.43] than in DZ twins (0.19, 95% CI 0.11-0.26), suggesting a role of genetic influence in FMD variation. Structural equation modeling showed that both genetic and unique environmental factors contributed significantly to the variation in FMD. The crude FMD heritability was 0.37 (95% CI 0.15-0.54). After adjustment for traditional cardiovascular risk factors, including age, total cholesterol, blood pressure, and body mass index, the heritability of FMD was 39% (95% CI 0.18-0.56). The remaining variation in FMD could be explained by individual-specific environment.

CONCLUSION

This is the first study using twins to estimate the relative contributions of genetics and environment to the variation in FMD in a US population. Our results demonstrate a moderate genetic effect on brachial artery FMD, independent of traditional coronary risk factors. Our data also highlight the importance of unique environment on the variability in FMD.