Browsing by Author "Rothhammer, Francisco"

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    Attention deficit hyperactivity disorder in Aymara children
    (SOC MEDICA SANTIAGO, 2012) Carrasco, Ximena; Daiber, Francisca; Rothhammer, Paula; Huerta, Daniela; Andrade, Claudia; Opazo, Patricia; Paz Lagos, Liza; Rothhammer, Francisco; Aboitiz, Francisco
    Background: The assessment of Attentional Deficit Hyperactivity Disorder (ADHD) among ethnic groups may reveal environmental or cultural variables that influence the appearance of this disorder. Aim: To assess the presence and characteristics of ADHD in two communities of the inland Arica valleys (Azapa and Lluta), where the Aymara population predominates. Material and Methods: Starting from a screening based on the Conner's test, we evaluated 79 children aged 8 to 13 years. Sixty children were of Aymara origin and 19 children were of non-Aymara origin. Twenty Aymara and 9 non-Aymara children had ADHD. They were compared with a group of patients from Santiago, Chile (110 children) that were previously assessed. Results: Patients from Azapa/Lluta displayed similar characteristics to those from Santiago. However the former had significantly less psychiatric comorbidities than the latter. On the other hand, the non-Aymara subgroup of Azapa/Lluta displayed an increased rate of comorbidities and was exclusively of the combined subtype, although their sample size is too small to draw strong conclusions. Conclusions: Although we cannot dismiss biological variables, the importance of family values and the respect to authorities may be protective factors for ADHD, associated to Aymara culture. Our findings suggest that the clinical characteristics of ADHD are not uniform among ethnic groups and cultures. The relative contribution of environmental and genetic factors in this variability remain to be determined. (Rev Med Chile 2012; 140: 1409-1416).
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    Cholecystectomy and digestive cancer in Chile: Complementary results from interrupted time series and aggregated data analyses
    (2025) Gonzalez, Constanza; Garcia-Perez, Alfonso; Nervi, Bruno; Munoz, Cesar; Morales, Erik; Losada, Hector; Merino-Pereira, Gina; Rothhammer, Francisco; Bermejo, Justo Lorenzo
    Gallbladder cancer (GBC) mortality in Chile is among the highest worldwide. In 2006, the Chilean government launched a programme guaranteeing access to gallbladder surgery (cholecystectomy) for patients aged 35-49 years. We evaluated the impact of this programme on digestive cancer mortality. After conducting an interrupted time series analysis of hospitalisation and mortality data from 2002 to 2018 publicly available from the Chilean Department of Health Statistics and Information, we calculated the change in the proportion of individuals without gallbladder since 10 years. We then estimated age, gender, region, and calendar-year standardised mortality ratios (SMRs) as a function of the change in the proportion of individuals without gallbladder. The cholecystectomy rate increased by 45 operations per 100,000 persons per year (95%CI 19-72) after the introduction of the health programme. Each 1% increase in the proportion of individuals without gallbladder since 10 years was associated with a 0.73% decrease in GBC mortality (95% CI -1.05% to -0.38%), but the negative correlation was limited to women, southern Chile and age over 60. We also found decreasing mortality rates for extrahepatic bile duct, liver, oesophageal and stomach cancer with increasing proportions of individuals without gallbladder. To conclude, 12 years after its inception, the Chilean cholecystectomy programme has markedly and heterogeneously changed cholecystectomy rates. Results based on aggregate data indicate a negative correlation between the proportion of individuals without gallbladder and mortality due to gallbladder and other digestive cancers, which requires validation using individual-level longitudinal data to reduce the potential impact of ecological bias.
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    Development and internal validation of a multifactorial risk prediction model for gallbladder cancer in a high-incidence country
    (2023) Boekstegers, Felix; Scherer, Dominique; Barahona Ponce, Carol; Marcelain, Katherine; Garate-Calderon, Valentina; Waldenberger, Melanie; Morales, Erik; Rojas, Armando; Munoz, Cesar; Retamales, Javier; de Toro, Gonzalo; Barajas, Olga; Rivera, Maria Teresa; Cortes, Analia; Loader, Denisse; Saavedra, Javiera; Gutierrez, Lorena; Ortega, Alejandro; Bertran, Maria Enriqueta; Bartolotti, Leonardo; Gabler, Fernando; Campos, Monica; Alvarado, Juan; Moisan, Fabricio; Spencer, Loreto; Nervi, Bruno; Carvajal-Hausdorf, Daniel; Losada, Hector; Almau, Mauricio; Fernandez, Plinio; Olloquequi, Jordi; Fuentes-Guajardo, Macarena; Gonzalez-Jose, Rolando; Bortolini, Maria Catira; Acuna-Alonzo, Victor; Gallo, Carla; Linares, Andres Ruiz; Rothhammer, Francisco; Lorenzo Bermejo, Justo
    Since 2006, Chile has been implementing a gallbladder cancer (GBC) prevention program based on prophylactic cholecystectomy for gallstone patients aged 35 to 49 years. The effectiveness of this prevention program has not yet been comprehensively evaluated. We conducted a retrospective study of 473 Chilean GBC patients and 2137 population-based controls to develop and internally validate three GBC risk prediction models. The Baseline Model accounted for gallstones while adjusting for sex and birth year. Enhanced Model I also included the non-genetic risk factors: body mass index, educational level, Mapuche surnames, number of children and family history of GBC. Enhanced Model II further included Mapuche ancestry and the genotype for rs17209837. Multiple Cox regression was applied to assess the predictive performance, quantified by the area under the precision-recall curve (AUC-PRC) and the number of cholecystectomies needed (NCN) to prevent one case of GBC at age 70 years. The AUC-PRC for the Baseline Model (0.44%, 95%CI 0.42-0.46) increased by 0.22 (95%CI 0.15-0.29) when non-genetic factors were included, and by 0.25 (95%CI 0.20-0.30) when incorporating non-genetic and genetic factors. The overall NCN for Chileans with gallstones (115, 95%CI 104-131) decreased to 92 (95%CI 60-128) for Chileans with a higher risk than the median according to Enhanced Model I, and to 80 (95%CI 59-110) according to Enhanced Model II. In conclusion, age, sex and gallstones are strong risk factors for GBC, but consideration of other non-genetic factors and individual genotype data improves risk prediction and may optimize allocation of financial resources and surgical capacity.
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    DRD4 dopamine receptor alleles in Chilean students of different ethnic origin and its relation with the risk for attention deficit/hyperactivity disorder
    (SOC MEDICA SANTIAGO, 2012) Rothhammer, Paula; Paz Lagos, Liza; Espinosa Parrilla, Yolanda; Aboitiz, Francisco; Rothhammer, Francisco
    Background: Worldwide diversity of alleles of D4 receptor gene (DRD4), linked to attention deficit hyperactivity disorder (ADHD), is mostly the result of length and single nucleotide polymorphisms in a 48-bp tandem repeat (VNTR). Alleles containing from two (2R) to eleven (11R) repeats have been identified. The most common are 4R, 7R and 2R. Aim: To study the association of ADHD risk with DRD4 genotypes in Chilean students. Subjects and Methods: ADHD risk data were obtained through the abbreviated Conner's Scale for School Teachers in 66 Aymara children (11 cases and 55 controls), 91 Rapa-Nui children (60 cases ad 31 controls) and 96 children from a mixed urban population from Santiago (51 cases and 45 controls). DNA extracted from saliva was amplified by polymerase chain reaction (PCR) to genotype the DRD4 VNTR. Results: The distribution of DRD4 alleles reveals that, beneath the 4R allele, 7R exhibits the second highest frequencies in Aymara and Santiago children. In Polynesian children, 2R ranks after 4R. A statistically significant association between ADHD risk and 2R/4R genotype was identified in Polynesian children (p < 0.05; odds ratio = 3.7). Conclusions: Different DRD4 genotypes are associated with ADHD phenotype in Chilean populations, probably as a consequence of their initial colonization history. (Rev Med Chile 2012; 140: 1276-1281).
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    Gallbladder Cancer Risk and Indigenous South American Mapuche Ancestry: Instrumental Variable Analysis Using Ancestry-Informative Markers
    (2023) Zollner, Linda; Boekstegers, Felix; Barahona Ponce, Carol; Scherer, Dominique; Marcelain, Katherine; Gárate-Calderón, Valentina; Waldenberger, Melanie; Morales Mejías, Erik; Rojas, Armando; Muñoz, César; Retamales, Javier; Toro, Gonzalo De; Vera Kortmann, Allan; Barajas, Olga; Rivera, María Teresa; Cortés, Analía; Loader, Denisse; Saavedra, Javiera; Gutiérrez, Lorena; Ortega, Alejandro; Bertrán, María Enriqueta; Bartolotti, Leonardo; Gabler, Fernando; Campos, Mónica; Alvarado, Juan; Moisán, Fabricio; Spencer, María Loreto; Nervi Nattero, Bruno; Carvajal-Hausdorf, Daniel; Losada, Héctor; Almau, Mauricio; Fernández, Plinio; Olloquequi, Jordi; Carter, Alice R.; Miquel P., Juan Francisco; Bustos, Bernabé I.; Fuentes Guajardo, Macarena; Gonzalez-Jose, Rolando; Bortolini, Maria Cátira; Acuña-Alonzo, Victor; Gallo, Carla; Ruiz Linares, Andrés; Rothhammer, Francisco; Bermejo, Justo Lorenzo
    A strong association between the proportion of indigenous South American Mapuche ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest indigenous people in Chile. We set out to assess the confounding-free effect of the individual proportion of Mapuche ancestry on GBC risk and to investigate the mediating effects of gallstone disease and body mass index (BMI) on this association. Genetic markers of Mapuche ancestry were selected based on the informativeness for assignment measure, and then used as instrumental variables in two-sample Mendelian randomization analyses and complementary sensitivity analyses. Results suggested a putatively causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% per 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.7 × 10−5) and also on gallstone disease (3.6% IVW risk increase, 95% CI 3.1% to 4.0%), pointing to a mediating effect of gallstones on the association between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative effect on BMI (IVW estimate −0.006 kg/m2, 95% CI −0.009 to −0.003). The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between the individual proportion of Mapuche ancestry and GBC risk previously noted in observational studies appears to be free of confounding, primary and secondary prevention strategies that consider genetic ancestry could be particularly efficient.
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    Identification of Circulating lncRNAs Associated with Gallbladder Cancer Risk by Tissue-Based Preselection, Cis-eQTL Validation, and Analysis of Association with Genotype-Based Expression
    (2022) Blandino, Alice; Scherer, Dominique; Rounge, Trine B.; Umu, Sinan U.; Boekstegers, Felix; Barahona Ponce, Carol; Marcelain, Katherine; Garate-Calderon, Valentina; Waldenberger, Melanie; Morales, Erik; Rojas, Armando; Munoz, Cesar; Retamales, Javier; de Toro, Gonzalo; Barajas, Olga; Rivera, Maria Teresa; Cortes, Analia; Loader, Denisse; Saavedra, Javiera; Gutierrez, Lorena; Ortega, Alejandro; Bertran, Maria Enriqueta; Gabler, Fernando; Campos, Monica; Alvarado, Juan; Moisan, Fabrizio; Spencer, Loreto; Nervi, Bruno; Carvajal-Hausdorf, Daniel E.; Losada, Hector; Almau, Mauricio; Fernandez, Plinio; Gallegos, Ivan; Olloquequi, Jordi; Fuentes-Guajardo, Macarena; Gonzalez-Jose, Rolando; Bortolini, Maria Catira; Gallo, Carla; Linares, Andres Ruiz; Rothhammer, Francisco; Lorenzo Bermejo, Justo
    Simple Summary Gallbladder cancer (GBC) is an aggressive disease with poor prognosis that urgently needs risk biomarkers for prevention. Long noncoding RNAs (lncRNAs) have been linked to various types of cancer and have good potential as circulating biomarkers. Prediction of lncRNA expression based on genotype data may contribute to quantify individual GBC risk even without direct lncRNA expression measurement. In this study, we investigate the relationship between GBC risk and genotype-based expression of circulating lncRNAs. Long noncoding RNAs (lncRNAs) play key roles in cell processes and are good candidates for cancer risk prediction. Few studies have investigated the association between individual genotypes and lncRNA expression. Here we integrate three separate datasets with information on lncRNA expression only, both lncRNA expression and genotype, and genotype information only to identify circulating lncRNAs associated with the risk of gallbladder cancer (GBC) using robust linear and logistic regression techniques. In the first dataset, we preselect lncRNAs based on expression changes along the sequence "gallstones -> dysplasia -> GBC". In the second dataset, we validate associations between genetic variants and serum expression levels of the preselected lncRNAs (cis-lncRNA-eQTLs) and build lncRNA expression prediction models. In the third dataset, we predict serum lncRNA expression based on individual genotypes and assess the association between genotype-based expression and GBC risk. AC084082.3 and LINC00662 showed increasing expression levels (p-value = 0.009), while C22orf34 expression decreased in the sequence from gallstones to GBC (p-value = 0.04). We identified and validated two cis-LINC00662-eQTLs (r(2) = 0.26) and three cis-C22orf34-eQTLs (r(2) = 0.24). Only LINC00662 showed a genotyped-based serum expression associated with GBC risk (OR = 1.25 per log2 expression unit, 95% CI 1.04-1.52, p-value = 0.02). Our results suggest that preselection of lncRNAs based on tissue samples and exploitation of cis-lncRNA-eQTLs may facilitate the identification of circulating noncoding RNAs linked to cancer risk.
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    Intratask Variability As a Correlate for DRD4 and SLC6A3 Variants : A Pilot Study in ADHD
    (2015) Henríquez Henríquez, Marcela Patricia; Villarroel del Pino, Luis A.; Henríquez, Hugo; Zamorano, Francisco; Rothhammer, Francisco; Aboitiz, Francisco
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    Pre-European Plant Consumption and Cultural Changes in the Coastal Lluta Valley, Atacama Desert, Northern Chile (Ca. 5140-390 Cal Yr BP)
    (2020) Garcia, Magdalena; Santoro, Calogero M.; McRostie, Virginia; Mendez-Quiros, Pablo; Salas-Egana, Carolina; Carter, Chris; Rothhammer, Francisco; Latorre, Claudio
    Pre-European Plant Consumption and Cultural Changes in the Coastal Lluta Valley, Atacama Desert, Northern Chile (Ca. 5140-390 Cal Yr BP). The introduction of domesticated plants into ancient hunting and gathering economic systems expanded and transformed human societies worldwide during the Holocene. These transformations occurred even in the oases and hyperarid environments of the Atacama Desert along the Pacific coast. Human groups inhabiting this desert incorporated adjacent habitats to the semi-tropical valleys through transitory or logistic camps like Morro Negro 1 (MN-1), in the Lluta valley (similar to 12 km from the littoral in northernmost Chile), into their settlement patterns. During the earliest occupation (Late Archaic period, 5140-4270 cal yr BP) people collected and consumed wild plants, although crops such as Lagenaria were present. Following a gap of more than 2000 years between 4270 and 1850, people returned and introduced new domesticated plants at the site (Gossypium, Zea mays, Capsicum), which displaced the use of wild reed (Schoenoplectus) rhizomes as the chief staple during the first occupation. This change in food consumption was linked to the transformations that took place during the Archaic-Formative transition, but did not entirely shift the ways of life of these coastal marine hunter-gatherers.
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    RISE AND DECLINE OF CHINCHORRO SACRED LANDSCAPES ALONG THE HYPERARID COAST OF THE ATACAMA DESERT
    (2012) Santoro, Calogero M.; Rivadeneira, Marcelo M.; Latorre, Claudio; Rothhammer, Francisco; Standen, Vivien G.
    The study of complex funerary ritual development among hunters and gatherers societies should take into account how people made up for the continuity of their social system without the support of centralized organizations. This research integrates cultural and natural factors to explore how the Chinchorro carried on with their way of life isolated at geographically restricted perennial river mouths with fresh water along the Atacama Desert in the Pacific coast of South America. Within these rather crowded settlings, they created and maintained a social system catalyzed by a complex funerary tradition, embodied by a unique funerary ideological discourse that resulted in the creation of a sacred landscape or "spiritscape". We argue that the extreme hyperaridity of the coastal Atacama Desert (21 degrees-17.30 degrees S), and the extraordinary biomass production of the marine littoral constituted a fundamental milieu for the maintenance of their long-term social system. The Chinchorro belief system lasted for several millennia (8,000-4,000 BP), but new ways of life and burial practices followed major changes in the coastal ecosystem they relied on, which would have influenced how the "old tradition" was manifested over time. Conversely, we sustain that these natural "constraints" faced by the Chinchorro along the coast of the Atacama Desert, were influential, in the course of their history or the way they socially organized themselves.