Results of a randomized controlled trial of the cannabis eCHECKUP TO GO personalized normative feedback intervention on reducing cannabis use, cannabis consequences, and descriptive norms

BACKGROUND

The prevalence of cannabis use disorder and its negative consequences among young adults has highlighted the need for prevention and early intervention programs. However, low treatment prevalence persists due to factors such as lack of perceived need, concerns about stigma, and limited access to treatment. To address these barriers, web-based cannabis interventions have been developed, but their efficacy remain limited. This study aims to evaluate the cross-site efficacy of the Cannabis eCHECKUP TO GO program, a web-based Personalized Normative Feedback and Protective Behavioral Strategies intervention for reducing cannabis use frequency and consequences in college students with willingness to change.

METHODS

Participants were 781 students from three universities (two in Canada, one in the US) who reported using cannabis in the past month and expressed interest in reducing or engaging in safer cannabis use. The study randomly assigned them to either an experimental group that received personalized normative feedback or a control group that received information on healthy stress management. The study collected follow-up data 4 weeks after the initial intervention and measured participants' frequency of cannabis use, number of cannabis consequences, descriptive and injunctive norms at both time points.

RESULTS

The results showed no significant reductions in cannabis use or negative consequences of use. However, students who received personalized normative feedback experienced a significant reduction in descriptive norms related to cannabis use, to be more in line with actual use.

CONCLUSION

This study suggests that more targeted interventions may be necessary for university students who are already using and seeking help to reduce their use.

Transcriptional repression across mitosis: mechanisms and functions

Transcription represents a central aspect of gene expression with RNA polymerase machineries (RNA Pol) driving the synthesis of RNA from DNA template molecules. In eukaryotes, a total of three RNA Pol enzymes generate the plethora of RNA species and RNA Pol II is the one transcribing all protein-coding genes. A high number of cis- and trans-acting factors orchestrates RNA Pol II-mediated transcription by influencing the chromatin recruitment, activation, elongation, and/or termination steps. The levels of DNA accessibility, defining open-euchromatin versus close-heterochromatin, delimits RNA Pol II activity as well as the encounter with other factors acting on chromatin such as the DNA replication or DNA repair machineries. The stage of the cell cycle highly influences RNA Pol II activity with mitosis representing the major challenge. In fact, there is a massive inhibition of transcription during the mitotic entry coupled with chromatin dissociation of most of the components of the transcriptional machinery. Mitosis, as a consequence, highly compromises the transcriptional memory and the perpetuation of cellular identity. Once mitosis ends, transcription levels immediately recover to define the cell fate and to safeguard the proper progression of daughter cells through the cell cycle. In this review, we evaluate our current understanding of the transcriptional repression associated with mitosis with a special focus on the molecular mechanisms involved, on the potential function behind the general repression, and on the transmission of the transcriptional machinery into the daughter cells. We finally discuss the contribution that errors in the inheritance of the transcriptional machinery across mitosis might play in stem cell aging.

Trajectories of oppositional defiant disorder severity from adolescence to young adulthood and substance use, mental health, and behavioral problems

Background

Oppositional Defiant Disorder (ODD) is a disruptive behavioral disorder; however, increasing evidence emphasizes irritable mood as a primary symptom of ODD.

Objectives

This study investigated whether heterogeneous groups (classes) of individuals can be differentiated based on ODD sub-dimensions (irritability and defiance) or on overall ODD symptoms longitudinally. We also examine associations between ODD trajectory class and comorbid substance use (heavy episodic drinking, cannabis use), mental health (depression and anxiety) and behavioral symptoms (ADHD, aggression and substance use) in both adolescence and young adulthood (controlling for adolescent levels of each of these concerns).

Method

Data were from a randomly recruited community sample of 662 Canadian youth (T1 ages 12-18) followed biennially for 10 years (T6 ages 22-29).

Results

Growth mixture models revealed trajectories classes of ODD based on severity of symptoms. A three-class solution provided the best fit with Low (n = 119; 18%), Moderate (n = 473; 71.5%), and High (n = 70; 10.6%) ODD classes. Class trajectory differences were similarity based on symptoms severity (rather than type) for symptom sub-dimensions (irritability defiance). Adolescent and young adult substance use, mental health symptoms, and behavioral problems were significantly higher for the High ODD trajectory class compared to both other classes. Youth in the Moderate ODD trajectory class also showed higher comorbid symptoms in adolescence and young adulthood, compared to the Low ODD trajectory class.

Conclusion

Early identification of children and adolescents with high or moderate ODD symptoms and interventions that simultaneously address defiance and irritability are supported by the findings.

Case Report: Necrotizing Erythema Nodosum as a Manifestation of Lepromatous Leprosy Relapse 50 Years after the Initial Infection

Leprosy is a chronic infection caused by Mycobacterium leprae and Mycobacterium lepromatosis that preferentially compromises peripheral nerve, skin, and mucous membranes. Colombia achieved the goal of leprosy elimination in 1997. However, in Urabá (Colombia), there has been an increase in leprosy cases beginning in 2020. This case report shows a leprosy relapse 5 decades after the initial infection debuted as a necrotizing erythema nodosum leprosum. Therefore, long-term follow-up of patients with risk factors for relapse is emphasized, especially those treated before the standard of multidrug therapy (dapsone, clofazimine, and rifampin). This case report stresses the importance the importance of clinical follow-up and surveillance of patients with these events of interest for the public health.

Abstract IA017: Targeting the mTOR pathway for the prevention of triple-negative breast cancer

Phase III cancer prevention clinical trials have shown that breast cancer prevention is feasible using anti-estrogen drugs. However, these drugs have not been widely accepted because of concerns about toxicity. In addition, anti-estrogen drugs do not prevent estrogen-negative breast cancers, including the most aggressive form of breast cancer, triple-negative breast cancer (TNBC), that does not express the estrogen receptor (ER), progesterone receptor, or the human epidermal growth factor receptor 2 (HER2). Our laboratory is focused on identifying growth-regulatory molecules that are essential for the growth of TNBCs. For this study, we identified mTOR as an essential growth-regulatory molecule that is highly expressed in TNBCs. We then investigated whether the mTOR inhibitor everolimus can prevent mammary tumors in transgenic mouse models including 4 models of TNBC and one model of ER-negative/HER2-positive breast cancer. Everolimus treatment significantly delayed mammary tumor formation but with a varying degree in all five mouse models. Everolimus treatment for up to 1 year was well tolerated with no observable toxicity. These results suggest that mTOR inhibitors may be promising drugs for the prevention of ER-negative and triple-negative breast cancers in women at risk of these aggressive breast cancers. Grant support: This research was supported by an NCI-PREVENT contract to P. Brown and A. Mazumdar (HHSN261201500018I/HHSN26100006).

Citation Format: Powel H. Brown, Abhijit Mazumdar, William Tahaney, Jamal Hill, Yun Zhang, Sumankalai Ramachandran, Jitesh Kawedia, Jing Qian, Alejandra Contreras, Michelle Savage, Lana Vornik. Targeting the mTOR pathway for the prevention of triple-negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr IA017.

Volviéndonos mejores: necesidad de acción inmediata ante el reto de la obesidad. Una postura de profesionales de la salud

La creciente epidemia de obesidad ha sido uno de los retos más importantes de salud pública en México durante los últimos años. Con apoyo de la Federación Mundial de Obesidad, en 2021 formamos un grupo de profesionales para identificar y resumir las acciones prioritarias en las que puede enfocarse nuestro país para hacer frente a esta epidemia. Al proceso de desarrollo y discusión de este grupo se sumaron más de 1 000 profesionales de la salud para retomar recomendaciones de documentos y guías de alto nivel previamente publicados. En conmemoración del Día Mundial de la Obesidad, en este 2022 se presenta esta postura como insumo para el desarrollo de acciones en el ámbito profesional y de los diferentes sectores, en la que se incluyen 10 recomendaciones de acción, desde la perspectiva poblacional hasta la atención individualizada, y se enfatiza en la importancia de la participación social, de las intervenciones integrales con visión centrada en la persona y de la sostenibilidad planetaria, además de mejorar la educación y las campañas de difusión, propiciar un ambiente promotor de entornos activos y blindar de conflictos de interés los esfuerzos de prevención y control. La postura hace un llamado para abordar la obesidad de manera seria, con base en la evidencia científica, oportuna e integral, con enfoque de curso de vida, de forma ética y sensible, y sin perpetuar las barreras del estigma de peso en la sociedad.

Longitudinal cohort study of injury type, settings, treatment and costs in British Columbia youth, 2003-2013

BACKGROUND

In 2010 in British Columbia (BC), Canada, total injury costs per capita were higher among youth aged 15-24 years than in any other age group. Injury prevention efforts have targeted injuries with high mortality (transportation injuries) or morbidity (concussions). However, the profile and health costs of common youth injuries (types, locations, treatment choices and prevention strategies) and how these change from adolescence to young adulthood is not known.

METHODS

Participants (n=662) were a randomly recruited cohort of BC youth, aged 12-18, in 2003. They were followed biennially across a decade (six assessments).

RESULTS

Serious injuries (defined as serious enough to limit normal daily activities) in the last year were reported by 27%-41% of participants at each assessment. Most common injuries were sprains or strains, broken bones, cuts, punctures or animal bites, and severe bruises. Most occurred when playing a sport or from falling. Estimated total direct cost of treatment per injury was approximately $2500. In addition, 25% experienced serious injuries at three or more assessments, indicating possible differences that warrents further investigation.

CONCLUSIONS

The occurence and health cost of common injuries to youth and young adults are underestimated in this study but are nevertheless substantial. Ongoing surveillence, awareness raising, and prevention efforts may be needed to reduce these costs.

NeuroD1 Dictates Tumor Cell Differentiation in Medulloblastoma

Tumor cells are characterized by unlimited proliferation and perturbed differentiation. Using single-cell RNA sequencing, we demonstrate that tumor cells in medulloblastoma (MB) retain their capacity to differentiate in a similar way as their normal originating cells, cerebellar granule neuron precursors. Once they differentiate, MB cells permanently lose their proliferative capacity and tumorigenic potential. Differentiated MB cells highly express NeuroD1, a helix-loop-helix transcription factor, and forced expression of NeuroD1 promotes the differentiation of MB cells. The expression of NeuroD1 in bulk MB cells is repressed by trimethylation of histone 3 lysine-27 (H3K27me3). Inhibition of the histone lysine methyltransferase EZH2 prevents H3K27 trimethylation, resulting in increased NeuroD1 expression and enhanced differentiation in MB cells, which consequently reduces tumor growth. These studies reveal the mechanisms underlying MB cell differentiation and provide rationales to treat MB (potentially other malignancies) by stimulating tumor cell differentiation.

Cheng et al. demonstrate that medulloblastoma cells retain the capacity to undergo differentiation. The differentiation of tumor cells is regulated by NeuroD1 expression, which is repressed by H3K27me3 in tumor cells. EZH2 inhibitors suppress medulloblastoma growth by stimulating tumor cell differentiation.

FoxO1 is required for high glucose-dependent cardiac fibroblasts into myofibroblast phenoconversion

In the normal heart, cardiac fibroblasts (CFs) maintain extracellular matrix (ECM) homeostasis, whereas in pathological conditions, such as diabetes mellitus (DM), CFs converse into cardiac myofibroblasts (CMFs) and this CFs phenoconversion increase the synthesis and secretion of ECM proteins, promoting cardiac fibrosis and heart dysfunction. High glucose (HG) conditions increase TGF-β1 expression and FoxO1 activity, whereas FoxO1 is crucial to CFs phenoconversion induced by TGF-β1. In addition, FoxO1 increases CTGF expression, whereas CTGF plays an active role in the fibrotic process induced by hyperglycemia. However, the role of FoxO1 and CTGF in CFs phenoconversion induced by HG is not clear. In this study, we investigated the effects of FoxO1 pharmacological inhibition on CFs phenoconversion in both in vitro and ex vivo models of DM. Our results demonstrate that HG induces CFs phenoconversion and FoxO1 activation. Moreover, AS1842856, a pharmacological inhibitor of FoxO1 activity, prevents CFs phenoconversion and CTGF expression increase induced by HG, whereas these results were corroborated by FoxO1 silencing. Additionally, K252a, a pharmacological blocker of CTGF receptor, prevents HG-induced CFs phenoconversion, which was corroborated with CTGF expression knockdown. Furthermore, through CFs isolation from heart of diabetic rats, we showed that hyperglycemia induces FoxO1 activation, the increase of CTGF expression and CFs phenoconversion, whereas the FoxO1 activity inhibition reverses the effects induced by hyperglycemia on CFs. Altogether, our results demonstrate that FoxO1 and CTGF are necessary for CFs phenoconversion induced by HG and suggest that both proteins are likely to become a potential targeted drug for fibrotic response induced by hyperglycemic conditions.

Male-Dominated Occupations and Substance Use Disorders in Young Adulthood

This article examined associations between male-dominated occupations and substance use disorders in young adulthood, accounting for adolescent experiences of work intensity (more than 15 hr a week at 16 to 17 years of age) and substance use (i.e., smoking, heavy drinking, cannabis, and illicit drug use). The moderating effects of biological sex and coming from a family with a low socioeconomic status (SES) were also assessed. Data were from a 10-year prospective study of community-based youth aged 12-18 in 2003 (T1; N = 662; 48% male; M_age = 15.5, SD = 1.9). Their occupations at ages 22-29 were categorized so that higher scores indicated more male-dominated occupations. Young adults in male-dominated occupations (more than 75% males) had lower education, worked in less prestigious occupations, and earned higher hourly wages than those in the other gendered-occupation groups. Work intensity in high school was associated with substance use at ages 18-25 and substance use was also associated with alcohol- and cannabis-use disorder symptoms and illicit drug use in young adulthood (ages 22-29). Adding to these effects, employment in a male-dominated occupation was associated with more cannabis-use disorder symptoms for the low, but not the high SES group. Public health messages need greater focus on preventing substance use disorders among individuals employed in male-dominated jobs in young adulthood. Efforts to promote self-assessment of problematic substance use and motivation to change may be particularly important for young workers.

A combinatorial biomarker predicts pathologic complete response to neoadjuvant lapatinib and trastuzumab without chemotherapy in patients with HER2+ breast cancer

BACKGROUND

HER2-positive (+) breast cancers, defined by HER2 overexpression and/or amplification, are often addicted to HER2 to maintain their malignant phenotype. Yet, some HER2+ tumors do not benefit from anti-HER2 therapy. We hypothesize that HER2 amplification levels and PI3K pathway activation are key determinants of response to HER2-targeted treatments without chemotherapy.

PATIENTS AND METHODS

Baseline HER2+ tumors from patients treated with neoadjuvant lapatinib plus trastuzumab [with endocrine therapy for estrogen receptor (ER)+ tumors] in TBCRC006 (NCT00548184) were evaluated in a central laboratory for HER2 amplification by fluorescence in situ hybridization (FISH) (n = 56). HER2 copy number (CN) and FISH ratios, and PI3K pathway status, defined by PIK3CA mutations or PTEN levels by immunohistochemistry were available for 41 tumors. Results were correlated with pathologic complete response (pCR; no residual invasive tumor in breast).

RESULTS

Thirteen of the 56 patients (23%) achieved pCR. None of the 11 patients with HER2 ratio <4 and/or CN <10 achieved pCR, whereas 13/45 patients (29%) with HER2 ratio ≥4 and/or CN ≥10 attained pCR (P = 0.0513). Of the 18 patients with tumors expressing high PTEN or wild-type (WT) PIK3CA (intact PI3K pathway), 7 (39%) achieved pCR, compared with 1/23 (4%) with PI3K pathway alterations (P = 0.0133). Seven of the 16 patients (44%) with HER2 ratio ≥4 and intact PI3K pathway achieved pCR, whereas only 1/25 (4%) patients not meeting these criteria achieved pCR (P = 0.0031).

CONCLUSIONS

Our findings suggest that there is a clinical subtype in breast cancer with high HER2 amplification and intact PI3K pathway that is especially sensitive to HER2-targeted therapies without chemotherapy. A combination of HER2 FISH ratio and PI3K pathway status warrants validation to identify patients who may be treated with HER2-targeted therapy without chemotherapy.

Abstract OT2-09-02: A phase I dose escalation study of topical bexarotene in women at high risk for breast cancer

Background: Breast cancer prevention with anti-estrogens, including tamoxifen, raloxifene, and exemestane, has been shown to reduce the incidence of hormone receptor-positive breast cancer. However, agents that can reduce the incidence of hormone receptor negative breast cancer are currently lacking. Rexinoids such as bexarotene are vitamin A analogues that have been shown to be involved in cell differentiation, growth, and apoptosis. In preclinical mouse models that develop ER-negative breast cancers, bexarotene showed a significant reduction in mammary tumor development. Oral bexarotene has been evaluated in BRCA mutation carriers and significant decreases in cyclin D1 were noted in breast cells suggesting biological activity of bexarotene on breast tissue. Systemic side effects of hyperlipidemia and hypothyroidism were also found. Data from chemoprevention studies with topical 4-hydroxytamoxifen support the concept of topical agents penetrating into the breast tissue and exhibiting biological activity in the tissue. We hypothesize that topical bexarotene can be applied to the breast as a chemoprevention agent with penetration to the breast tissue without subsequent systemic side effects and toxicity as seen with oral bexarotene.

Trial Design: Women at high risk for breast cancer will be recruited and assigned to one of three different dose levels: 10mg (1ml) every other day, 10mg (1ml) daily, 20mg (2ml) daily to one unaffected breast for 4 weeks. The primary endpoint of the study is to determine the recommended phase II dose of topical bexarotene 1% gel for evaluation in healthy at-risk women. Dose Limiting Toxicity (DLT) is defined as a grade 2 skin adverse event that persists for at least 6 days or any grade 3 or greater adverse event related to the study drug. A grade 2 skin adverse event that recurs and persists for at least 3 days is also a DLT. The Maximum Tolerated Dose (MTD) will be defined as the highest dose level at which no more than 2 participants experience a DLT among 10 participants treated. A conservative modification of the standard “3+3” design will be applied. The first three participants will be assigned to the lowest dose level. New cohorts of 3-4 participants will not be treated until toxicity has been fully evaluated for all current participants through 4 weeks. Once the MTD has been determined, an expansion cohort of an additional 10 patients will be recruited at the MTD to further evaluate safety and toxicity at this dose level as well bexarotene concentration in the breast tissue. Secondary endpoints include serum bexarotene level, tissue bexarotene levels, and changes in thyroid function tests, lipid profile, and calcium. The planned accrual for this study if maximally accrued to all dose levels and the dose expansion cohort will be 40 participants.

Citation Format: Thomas PS, Patel AB, Contreras A, Liu DD, Lee JJ, Khan S, Vornik LA, Dimond EP, Perloff M, Heckman-Stoddard BM, Brown PH. A phase I dose escalation study of topical bexarotene in women at high risk for breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-09-02.

Abstract PD3-07: A phase II pre-surgical trial of lapatinib for the treatment of women with HER2 positive or EGFR positive ductal carcinoma in situ

Background: Estrogen receptor (ER)-negative tumors and human epidermal growth factor 2-Neu (HER2) positive breast cancers are known to be more clinically aggressive subtypes of breast cancer and account for 30% of all breast cancers. Women with HER2 + breast cancers, whether ER+ or ER -, require cytotoxic chemotherapy with a HER2-targeting agent, and often have adverse outcomes. Thus, preventive agents are needed to reduce the incidence of these subtypes of aggressive breast cancer. Lapatinib, a dual tyrosine kinase inhibitor, inhibits epidermal growth factor receptors (EGFR) and HER2 kinases and has shown to decrease breast cell proliferation in invasive breast cancer and adjacent premalignant lesions. Therefore, we conducted a multi-institutional randomized Phase II clinical trial to study the effects of the signal transduction inhibitor lapatinib in women with HER2-positive or EGFR-positive ductal carcinoma in situ (DCIS).

Methods: Randomized participants received either lapatinib (750mg, 1000mg, or 1500mg) or placebo daily for 2-6 weeks prior to their surgery. After minimal accrual, the trial was later amended to lapatinib 1000mg or placebo. Pre-treatment breast tissue was obtained from initial diagnostic core biopsy and post-treatment breast tissue was obtained from surgical excision specimen. Blood was obtained prior to surgery to assess serum lapatinib level. Participants kept a daily symptom assessment log and had a cardiac assessment at baseline and prior to surgery. Patients were instructed to take drug up to and including the day before surgery. The dual primary endpoint for this study was change in proliferation in pre- versus post-treatment biopsies between the two treatment arms, as measured by Ki67 as well as toxicity assessment. Secondary endpoints included incidence of DCIS at surgery and modulation of tissue biomarker expression in growth factor receptors (EGFR, ErbB2); phosphorylated growth factor receptor (phospho-ErbB2); signal transduction markers (MAPK, phospho-MAPK); hormone receptors (ER, PR); and p27.

Results:Twenty-two women (mean age: 51; range: 32-66) with HER2+ or EGFR+ DCIS were treated with lapatinib (1,000 or 1,500 mg) or placebo for 2–6 weeks prior to surgical excision. Ki67 expression was significantly decreased in the lapatinib treatment arms compared to placebo (p=0.0122). Diarrhea, fatigue, and skin reactions were notable adverse events that occurred predominately in the lapatinib arm compared to placebo. No grade 3 or 4 events related to the study drug were noted during the study. No changes were noted in cardiac function. DCIS was present in all surgical specimens in both arms. Invasive breast cancer was noted in 1 patient on lapatinib 1000mg and 3 patients on placebo. No statistically significant changes were noted in signal transduction biomarkers

Conclusion:These results demonstrate the effectiveness of lapatinib in reducing proliferation in women with EGFR+ or HER2+ DCIS. Even low-grade toxicities can deter use of an agent in the prevention setting. This and the lack of a risk model for HER2+ and triple negative breast cancer make the development of larger scale clinical prevention trials of lapatinib for the prevention a challenge.

Citation Format: Thomas PS, Contreras A, Pruthi S, Krontiras H, Rimawi M, Garber J, Wang T, Hilsenbeck SG, Vornik LA, Gilmer T, Friedman R, Heckman-Stoddard BM, Dunn B, Kuerer H, Brown PH. A phase II pre-surgical trial of lapatinib for the treatment of women with HER2 positive or EGFR positive ductal carcinoma in situ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-07.

Abstract GS1-02: Towards a human breast cell atlas

The human breast tissue consists of lobules connected to a complex network of ducts that are evolutionarily designed to produce and transport milk to nourish offspring. Histopathology has identified 10 major cell types based on morphological features but have provided limited information on cell states - the transcriptional programs of cell types that reflect different biological functions. In this study, we have generated an unbiased 'cell atlas' of the normal human breast to define the cell types and cell states using single cell RNA sequencing methods. We performed 3' microdroplet based single cell RNA sequencing of 31,442 stromal cells from 11 women with pathologically normal breast tissues that were collected from mastectomies. Unbiased expression analysis identified three major cell types: epithelial cells (luminal and basal), fibroblasts and endothelial cells, in addition to several minor cell types: macrophages, T-cells, natural killer cells, pericytes and smooth muscle cells. Analysis of cell states of these cell types revealed different transcriptional programs in luminal epithelial cells (hormone receptor positive and secretory), basal epithelial cells (myoepithelial or basement-like), endothelial cells (lymphatic or vascular), macrophages (M1 or M2) and fibroblasts (three subgroups) and provided insight into progenitors of each cell types. These data provide a valuable reference for the research community and will provide new insights into how normal cell types are transformed in the tumor microenvironment to promote or inhibit the progression of breast cancer.

Citation Format: Seth TK, Bai S, Hu M, Sei E, Wood A, Wiley J, Chen H, Contreras A, Teshome M, Lim B, Navin NE. Towards a human breast cell atlas [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS1-02.

A panel of 32 AIMs suitable for population stratification correction and global ancestry estimation in Mexican mestizos

BACKGROUND

Association studies are useful to unravel the genetic basis of common human diseases. However, the presence of undetected population structure can lead to both false positive results and failures to detect genuine associations. Even when most of the approaches to deal with population stratification require genome-wide data, the use of a well-selected panel of ancestry informative markers (AIMs) may appropriately correct for population stratification. Few panels of AIMs have been developed for Latino populations and most contain a high number of markers (> 100 AIMs). For some association studies such as candidate gene approaches, it may be unfeasible to genotype a numerous set of markers to avoid false positive results. In such cases, methods that use fewer AIMs may be appropriate.

RESULTS

We validated an accurate and cost-effective panel of AIMs, for use in population stratification correction of association studies and global ancestry estimation in Mexicans, as well as in populations having large proportions of both European and Native American ancestries. Based on genome-wide data from 1953 Mexican individuals, we performed a PCA and SNP weights were calculated to select subsets of unlinked AIMs within percentiles 0.10 and 0.90, ensuring that all chromosomes were represented. Correlations between PC1 calculated using genome-wide data versus each subset of AIMs (16, 32, 48 and 64) were r2 = 0.923, 0.959, 0.972 and 0.978, respectively. When evaluating PCs performance as population stratification adjustment covariates, no correlation was found between P values obtained from uncorrected and genome-wide corrected association analyses (r2 = 0.141), highlighting that population stratification correction is compulsory for association analyses in admixed populations. In contrast, high correlations were found when adjusting for both PC1 and PC2 for either subset of AIMs (r2 > 0.900). After multiple validations, including an independent sample, we selected a minimal panel of 32 AIMs, which are highly informative of the major ancestral components of Mexican mestizos, namely European and Native American ancestries. Finally, the correlation between the global ancestry proportions calculated using genome-wide data and our panel of 32 AIMs was r2 = 0.972.

CONCLUSIONS

Our panel of 32 AIMs accurately estimated global ancestry and corrected for population stratification in association studies in Mexican individuals.

Cronobacter sakazakii and Microbiological Parameters in Dairy Formulas Associated With a Food Alert in Chile

The objective of this study was to evaluate the presence of Cronobacter sakazakii and microbiological parameters in dairy products associated with a food alert. Ninety dairy product samples were analyzed, including seven commercial brands and two product types (liquid and powdered) from four countries. Aerobic plate count (APC) and Enterobacteriaceae count were performed according to Chilean standards. Cronobacter spp. and C. sakazakii were identified by polymerase chain reaction real time amplification of rpoB and cgcA genes and the genotype by multilocus sequence typing. Eighty-eight percent of dairy products showed APC higher than the detection limit. Fifty percent of liquid commercial brand samples contained APC: 2.6, 2.3, 1.1, and 2.9 CFU/mL in brands A, C, E, and G, respectively. Results for powdered commercial brands were 3.0, 3.6, and 5.7 CFU/g in brands B, D, and F, respectively. Maximum count (5.7 CFU/g) occurred in brand F dairy product manufactured in Chile. Enterobacteriaceae were found in 55% of the samples, 64% in liquid and 51% in powdered commercial brands. In 50% of brands B, D, and E, samples contained 2.9, 2.8, and 2.7 log CFU/g, respectively. Only liquid commercial brands from the United States had Enterobacteriaceae values between 0.1 and 4.5 CFU/mL. Seventeen suspicious strains were isolated and nine were identified as Enterobacter spp. Only eight suspicious strains from four powdered commercial brands (Chile and Singapore) were confirmed as C. sakazakii by rpoB and cgcA gene amplification and fusA sequencing. C. sakazakii prevalence in the analyzed samples was 8.8%. There were 11% of powdered milk brands that contained APC between 4.0 and 4.7 log CFU/g and 55% of the samples contained Enterobacteriaceae. C. sakazakii was found in dairy products manufactured in Chile and Singapore. On the basis of this information, the Chilean Ministry of Health (RSA) decreed a national and international food alert and recalled all the product batches that resulted positive in the present study from supermarkets and pharmacies.

Epidemiological role of birds in the transmission and maintenance of zoonoses

The risk of zoonoses spreading from birds to humans is lower, quantitatively speaking, than the risk of transmission between other host groups, because the two taxonomic groups share fewer pathogens. Nevertheless, birds have a number of epidemiological characteristics that make them extremely important hosts in the transmission and maintenance of zoonoses, including their susceptibility to pathogens that are extremely hazardous to humans (such as highly pathogenic avian influenza virus, West Nile virus and Chlamydia psittaci) and their ability to travel long distances, especially in the case of migratory birds. The fact that the human diet includes poultry products (meat, eggs and their by-products) also means that most human cases of foodborne zoonoses are infections of avian origin. Lastly, close contact between humans and pet birds or urban birds leads to interactions of public health concern. This article sets out to describe the main factors that determine the role of birds in the epidemiology of zoonotic infections.

Vitamin D deficiency is common and is associated with overweight in Mexican children aged 1-11 years

OBJECTIVE

To assess vitamin D dietary sources, intake and 25-hydroxyvitamin D status and their association with individual and sociodemographic characteristics in Mexican children.

DESIGN

Data obtained from 2695 children aged 1-11 years from the Mexican National Health and Nutrition Survey (2012) were analysed. Diet was assessed by a 141-item FFQ. 25-Hydroxyvitamin D was measured by a chemiluminescent assay.

RESULTS

Mean vitamin D intake was 3·38 (se 0·09) µg/d (135·2 (se 3·6) IU/d) among pre-school children and 2·85 (se 0·06) µg/d (114·0 (se 2·4) IU/d) in school-age children. Milk accounted for 64·4 % of vitamin D intake in pre-school children and 54·7 % in school-age children. Vitamin D deficiency (serum 25-hydroxyvitamin D<50 nmol/l) was 25·9 % in pre-schoolers and 36·6 % in school-age children. Overweight/obese school-age children had a higher risk of vitamin D deficiency compared with normal-weight children (OR=2·23; 95 % CI 1·36, 3·66; P<0·05).

CONCLUSIONS

Vitamin D intakes are low in Mexican children, and milk is the main source of the vitamin. Vitamin D deficiency is common and associated with overweight in school-age children.

Accuracy of cotinine serum test to detect the smoking habit and its association with periodontal disease in a multicenter study

Background

The validity of the surveys on self-reported smoking status is often questioned because smokers underestimate cigarette use and deny the habit. It has been suggested that self-report should be accompanied by cotinine test. This report evaluates the usefulness of serum cotinine test to assess the association between smoking and periodontal status in a study with a large sample population to be used in studies with other serum markers in epidemiologic and periodontal medicine researches.

Material and Methods

578 patients who were part of a multicenter study on blood biomarkers were evaluated about smoking and its relation to periodontal disease. Severity of periodontal disease was determinate using clinical attachment loss (CAL). Smoking was assessed by a questionnaire and a blood sample drawn for serum cotinine determination.

Results

The optimal cut-off point for serum cotinine was 10 ng/ml. Serum cotinine showed greater association with severity of CAL than self-report for mild-moderate CAL [OR 2.03 (CI95% 1.16-3.53) vs. OR 1.08 (CI95% 0.62-1.87) ] advanced periodontitis [OR 2.36 (CI95% 1.30- 4.31) vs. OR 2.06 (CI95% 0.97-4.38) ] and extension of CAL > 3 mm [ OR 1.78 (CI95% 1.16-1.71) vs. 1.37 (CI95% 0.89-2.11)]. When the two tests were evaluated together were not shown to be better than serum cotinine test.

Conclusions

Self-reported smoking and serum cotinine test ≥ 10ng/ml are accurate, complementary and more reliable methods to assess the patient’s smoking status and could be used in studies evaluating serum samples in large population and multicenter studies. Clinical Relevance: The serum cotinine level is more reliable to make associations with the patient’s periodontal status than self-report questionnaire and could be used in multicenter and periodontal medicine studies.

Key words:Biological markers, serum, cotinine, periodontitis, smoking.

Eosin-mediated synthesis of polymer coatings combining photodynamic inactivation and antimicrobial properties

Eosin-derived coatings exhibiting photodynamic bacterial inactivation and antibacterial properties.

Sensitivity of two methods to detect Mycoplasma agalactiae in goat milk

BACKGROUND

Laboratory diagnostic techniques able to detect Mycoplasma agalactiae are essential in contagious agalactia in dairy goats. This study was designed: 1) to determine the detection limits of PCR and culture in goat milk samples, 2) to examine the effects of experimental conditions including the DNA extraction method, PCR technique and storage conditions (fresh versus frozen stored milk samples) on these methods and 3), to establish agreement between PCR and culture techniques using milk samples from goats with mastitis in commercial dairy herds. The study was conducted both on artificially inoculated and field samples.

RESULTS

Our findings indicate that culture is able to detect M. agalactiae in goat milk at lower concentrations than PCR. Qualitative detection of M.agalactiae by culture and PCR was not affected by sample freezing, though the DNA extraction method used significantly affected the results of the different PCR protocols. When clinical samples were used, both techniques showed good agreement.

CONCLUSIONS

The results from this study indicate that both culture and PCR are able to detect M. agalactiae in clinical goat mastitis samples. However, in bulk tank milk samples with presumably lower M. agalactiae concentrations, culture is recommended within the first 24 h of sample collection due to its lower limit of detection. To improve the diagnostic sensitivity of PCR in milk samples, there is a need to increase the efficiency of extracting DNA from milk samples using protocols including a previous step of enzymatic digestion.

The application of non-Saccharomyces yeast in fermentations with limited aeration as a strategy for the production of wine with reduced alcohol content

High alcohol concentrations reduce the complexity of wine sensory properties. In addition, health and economic drivers have the wine industry actively seeking technologies that facilitate the production of wines with lower alcohol content. One of the simplest approaches to achieve this aim would be the use of wine yeast strains which are less efficient at transforming grape sugars into ethanol, however commercially available wine yeasts produce very similar ethanol yields. Non-conventional yeast, in particular non-Saccharomyces species, have shown potential for producing wines with lower alcohol content. These yeasts are naturally present in the early stages of fermentation but in general are not capable of completing alcoholic fermentation. We have evaluated 48 non-Saccharomyces isolates to identify strains that, with limited aeration and in sequential inoculation regimes with S. cerevisiae, could be used for the production of wine with lower ethanol concentration. Two of these, Torulaspora delbrueckii AWRI1152 and Zygosaccharomyces bailii AWRI1578, enabled the production of wine with reduced ethanol concentration under limited aerobic conditions. Depending on the aeration regime T. delbrueckii AWRI1152 and Z. bailii AWRI1578 showed a reduction in ethanol concentration of 1.5% (v/v) and 2.0% (v/v) respectively, compared to the S. cerevisiae anaerobic control.

Oncoplastic breast surgery: initial experience at the Centro Clinico de Estereotaxia-CECLINES, Caracas, Venezuela

BACKGROUND

Breast-conserving surgery (BCS) may sometimes lead to deformities in the remaining breast. Oncoplastic surgery (OPS) aims to improve our aesthetic results even in the case of major volume resections. The purpose of this study is to provide an objective evaluation of our initial experience with OPS, mainly based on the levels of satisfaction reported by both patients and surgeons.

PATIENTS AND METHODS

This prospective study was performed at CECLINES in Caracas, Venezuela, between January 2011 and October 2012. It involved 107 consecutive patients in two groups: 52 patients with level II OPS versus 55 patients with 'standard' BCS (SBCS). We evaluated the level of satisfaction and cosmetic outcome at 6 and 12 months post-operation using a score from 1 (bad) to 5 (excellent). The cosmetic score was recorded during the follow-up by the surgeon, by phone calls, and photographs were reviewed by a panel of four observers.

RESULTS

The participation rate in the cosmetic outcome/level of satisfaction evaluation was 100% at 6 months and 96.2% at 12 months. The average tumour size was 23 mm [standard deviation (SD): 13.5] for the OPS group versus 17.6 mm (SD: 8.3) for the SBCS group (p = 0.017). The average weight for the surgical specimen was 101 g (range: 30-512 g) in the OPS group versus 60.4 g (range: 20-135 g) in the SBCS group (p = 0.004). The OPS techniques most performed were round block 40.3% (21/52), inverted T mammoplasty 26.8% (14/52) and vertical scar mammoplasty 15.3% (8/52). Of all the patients, 51.9% (27/52) had symmetrisation procedures performed distributed according to the period of the study: 77.2% (17/22) in 2011, 56.6% (17/30) in 2012, and 18.1% (6/33) in 2013. The rate of complications was 5.7% (3/52) in the OPS group and 0% for the SBCS group (p < 0.005). The average cosmetic score at 6 months by patients in the OPS group was 4.4; patient satisfaction scores of 4 (good) and 5 (excellent) were 88.4%. In the SBCS group at 6 months, the mean score reported by patients was 4.2, with scores 4-5 being 83.4% (p = 0.644). The cosmetic score by surgeons in the OPS group at 6 months was 4.5; the surgeon satisfaction scores of 4-5 were 94.2%. In the SBCS group, the surgeons' mean score at 6 months was 4.1, with 84.5% of scores being 4 or 5 (p < 0.005). The final cosmetic score by patients in the OPS group at 12 months was 4.5; patient satisfaction scores of 4-5 were 90.4%. In the SBCS group, the final mean score at 12 months by patients was 4.2, with 77.5% of scores being 4 or 5 (p < 0.005). The final cosmetic score by surgeons in the OPS group at 12 months was 4.5; surgeon satisfaction scores of 4-5 were 92.3%. In the SBCS group, the surgeons' final mean score at 12 months was 4.1, with 84.5% of scores being 4 or 5 (p < 0.005).

CONCLUSIONS

OPS provides good satisfaction rates. An SBCS when an OPS is not indicated mostly results in good satisfaction levels and cosmetic scores. Usually, the results remain stable after 6 months. The use of OPS allows the excision of bigger lesions and surgical specimens. Symmetrisation procedures are not always required. With the appropriate patient selection, the rate of complications is low for both OPS and SBCS.

Abstract PD1-2: PIK3CA mutations and/or low PTEN predict resistance to combined anti-HER2 therapy with lapatinib and trastuzumab and without chemotherapy in TBCRC006, a neoadjuvant trial of HER2-positive breast cancer patients

We have recently reported that in patients with HER2-positive breast cancer, neoadjuvant targeted therapy with lapatinib and trastuzumab to more completely block the HER receptor layer, combined with endocrine therapy (in ER-positive tumors) and without chemotherapy led to a substantial 27% pathologic complete response (pCR) rate in the breast. Activation of downstream signaling pathways may lead to resistance to therapies targeting the HER pathway receptors. Aberrant activation of the PI3K pathway via decreased levels of PTEN and/or the presence of activating PIK3CA mutations has been implicated in resistance to targeted anti-HER2 therapy, but results of clinical trials are all confounded by the co-administration of chemotherapy and are inconsistent. We sought to clarify the role of these variables in predicting pCR, a surrogate for long-term outcome, in patients treated with potent targeted therapy alone in a prospective Phase II neoadjuvant trial in patients with HER2-positive breast cancer.

Patients with large tumors (median 6 cm) were given 12 weeks of lapatinib plus trastuzumab followed by surgery (Rimawi et al. JCO, 2013). Serial tissue biopsies were obtained from study participants. For this study, we focused on baseline pre-treatment characteristics. PTEN protein levels were measured by IHC and scored using the H-score. PIK3CA mutations were identified on extracted DNA using multiplex PCR with targeted next generation sequencing (the Ion Torrent 50-gene cancer mutation panel).

Of 64 evaluable patients, tissue was available on 59 for PTEN IHC, and sufficient DNA was available on 33 for the mutation panel. PTEN median H-score was 100 (range 0-300). PTEN status when dichotomized by the median was correlated with pCR (32% in high PTEN vs. 9% in low PTEN, p = 0.04). Activating PIK3CA mutations were identified in 12 out of 33 tumors (36%; 3 mutations in the helical and 9 in the catalytic domain) and were independent of ER status. None of the patients whose tumors harbored a PIK3CA mutation achieved pCR (p = 0.06). There was no association between PTEN status and PIK3CA mutation suggesting they are independent variables (p = 0.44). When PIK3CA mutations were considered together with PTEN status, there were 31 cases with data on both. The overall pCR rate in this cohort was 16% (lower than pCR rate observed in the overall trial). However, 0/17 cases (0%) with a mutation and/or PTEN low expression (&lt;100 H score) had a pCR compared to 5/14 cases (36%) with PI3KCA wild type and high PTEN levels (p = 0.01).

We conclude that PI3K pathway activation downstream of HER2 as a result of either low PTEN or activating PIK3CA mutation results in resistance to the combination of lapatinib and trastuzumab. This is the first report on patient tissue samples from a neoadjuvant trial using the combination of lapatinib and trastuzumab without chemotherapy. If validated in a larger cohort, our findings suggest that patients with HER2 positive tumors and who also harbor aberrant downstream PI3K pathway activation may benefit from the addition of PI3K/Akt/mTOR inhibitors to potent HER2 blockade.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD1-2.

Williams' neural stem cells: new model for insight into microRNA dysregulation

Williams syndrome (WS) is a neurodevelopmental genetic disorder, due to a 7q11.23 hemizygous deletion. WS has a characteristic neurocognitive profile that includes intellectual disability (ID). Haploinsufficiency of some of the deleted genes is partially associated with the cognitive phenotype. The aim of this paper is to determine the differences in the microRNA (miRNA) expression in WS patients, using a neural cell model from the patients olfactory neuroepithelium (ONE), and to establish the relationship with those genes involved in neurodevelopment and neural function. To assess these goals, we made a comparative analysis of the miRNAs expression profile between WS patients and controls. Through an in silico analysis, we established potential pathways and targets associated with neural tissue. The expression profile shows 14 dysregulated miRNAs, including nervous system (NS)-rich miRNAs such as miR-125b, let-7c and miR-200. Most of these miRNAs have potential targets associated with NS functions while others have been reported to have specific neuronal functions. These data suggest that miRNAs widely contribute to the regulation of neurodevelopmental intrinsic processes, and that specific miRNAs could participate in WS neurobiology.