Browsing by Author "Lopez, Rodrigo"

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    Aortic Stenosis and Acquired von Willebrand Disease: Lack of Association
    (W B SAUNDERS CO-ELSEVIER INC, 2011) Carrasco, Esperanza; Lopez, Rodrigo; Rattalino, Marcos; Lema, Guillermo; Pereira, Jaime; Canessa, Roberto; Zalaquett, Ricardo; Carvajal, Claudia; Carrasco, Paulo
    Objectives: The association between aortic stenosis (AS) and acquired von Willebrand disease type 2A has been described. It may be present in up to 90% of patients with AS. Shear stress has been proposed as the underlying mechanism; however, the physiopathology of this condition is not completely understood. No specific treatment has been studied in this specific population besides aortic valve replacement (AVR). As a coadjuvant therapy, some cardiac surgery centers use desmopressin routinely. The authors report the first stage of an ongoing study designed to compare the effects of desmopressin versus placebo in patients with severe AS scheduled for AVR. Because of the different incidences of the acquired von Willebrand type 2A reported in the literature, the first stage was conducted to describe the incidence of this clinical association in the present population, allowing the sample size for the second stage of the study to be obtained.
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    Contesting the conventional wisdom of periodontal risk assessment
    (2024) Raittio, Eero; Lopez, Rodrigo; Baelum, Vibeke
    Over the years, several reviews of periodontal risk assessment tools have been published. However, major misunderstandings still prevail in repeated attempts to use these tools for prognostic risk prediction. Here we review the principles of risk prediction and discuss the value and the challenges of using prediction models in periodontology. Most periodontal risk prediction models have not been properly developed according to guidance given for the risk prediction model development. This shortcoming has led to several problems, including the creation of arbitrary risk scores. These scores are often labelled as 'high risk' without explicit boundaries or thresholds for the underlying continuous risk estimates of patient-important outcomes. Moreover, it is apparent that prediction models are often misinterpreted as causal models by clinicians and researchers although they cannot be used as such. Additional challenges like the critical assessment of transportability and applicability of these prediction models, as well as their impact on clinical practice and patient outcomes, are not considered in the literature. Nevertheless, these instruments are promoted with claims regarding their ability to deliver more individualized and precise periodontitis treatment and prevention, purportedly resulting in improved patient outcomes. However, people with or without periodontitis deserve proper information about their risk of developing patient-important outcomes such as tooth loss or pain. The primary objective of disseminating such information should not be to emphasize assumed treatment efficacy, hype individualization of care, or promote business interests. Instead, the focus should be on providing individuals with locally validated and regularly updated predictions of specific risks based on readily accessible and valid key predictors (e.g. age and smoking).
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    Cytokine profiles and the dynamic of gingivitis development in humans
    (2022) Leite, Fabio R. M.; Nascimento, Gustavo G.; Moller, Holger J.; Belibasakis, Georgios N.; Bostanci, Nagihan; Smith, Patricio C.; Lopez, Rodrigo
    Aim To investigate the relationship between cytokine profiles and "fast" and "slow" patterns of gingival inflammation development. Materials and Methods Forty-two adults participated in an experimental gingivitis study, comprising a 2-week hygiene phase (clinical examination and professional cleaning); a 3-week induction phase (absence of oral hygiene); and a 2-week resolution phase (re-establishment of oral hygiene). Plaque and gingival inflammation scores were assessed. Interferon-gamma (IFN-gamma), interleukin (IL)-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and tumour necrosis factor-alpha (TNF-alpha) from gingival crevicular fluid were collected and measured by multiplex ELISA. Group-based-trajectory-modelling (GBTM) was used to model cytokine profiles over the induction phase. The effect of gingival inflammation on cytokine levels over time was estimated with mixed-effects modelling. Results GBTM analysis revealed two cytokine profiles, "non-organized response" (IL-4, IL-6, IL-8, IL-12, and IL-13) and "organized response" (IL-2, IL-10, and TNF-alpha). Among the "slow" responders, neither cytokine profile was associated with gingivitis. In contrast, a "fast" response was associated with a higher "non-organized response" factor (coef. 0.14) and a lower "organized response" factor (coef. -0.03). Conclusion A "fast" gingivitis development was associated with a higher "non-organized response" and a lower "organized response", which may elucidate the role of individual variability in gingivitis susceptibility.
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    Dental service use among adults with incident type 2 diabetes, rheumatoid arthritis or inflammatory bowel disease
    (2024) Raittio, Eero; Baelum, Vibeke; Nascimento, Gustavo G.; Lopez, Rodrigo
    ObjectivesIt is not clear if or how the incidence of systemic conditions like type 2 diabetes mellitus (DM2), rheumatoid arthritis (RA) or inflammatory bowel disease (IBD) affects dental service utilization. Using nationwide Danish register data, the aim of this study was to analyse the use of dental services 7 years before and after being diagnosed with DM2, RA or IBD between 1997 and 2011.MethodsInformation about incident DM2 was obtained from the National Diabetes Register, and incident RA and IBD were defined based on diagnosis codes of hospital contacts identified through the National Patient Register. Separately, for each of the three conditions, each individual with the incident condition was matched to one control individual based on age, gender, country of origin, municipality of residence, highest completed education, the main source of income and income using coarsened exact matching in the year of incidence. The use of dental services and treatments received within each calendar year from 7 years before to 7 years after getting the condition were analysed with generalized estimating equations.ResultsPeople with incident DM2 were less likely (by seven percentage points) to be dental service users within a year than people without incident DM2 for a period extending from up to 7 years prior to 7 years after the diagnosis. This difference even slightly increased after the diagnosis. Those with incident IBD exhibited a consistently but modestly higher proportion of dental service use (three percentage points) than those without incident IBD before and after the diagnosis. Differences in the use of services between those with or without incident RA were minor. For all three systemic diseases, detected differences mainly mirrored differences in the provision of supragingival scaling and restorative treatment.ConclusionsThe findings suggest that the impact of these three systemic conditions on dental service use was minor.
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    Educational level, gender and health practices regarding COVID-19 in N'Djamena, Chad: A cross-sectional study
    (PAGEPRESS PUBL, 2022) Dzomo, G. Rodrigue Takoudjou; Bernales, Margarita; Gomez-Virseda, Carlos; Deassal, Francis; Lopez, Rodrigo
    COVID-19 is affecting different countries and populations unequally. In this sense, sub-Saharan countries represent a particularly vulnerable context due to their unique demographic and health circumstances. A holistic approach to Covid-19 is urged, one that considers the social-cultural contexts of people's lives. Using Social Determinants of Health (SDH) as framework, we explore which variables could explain the differences in health practices regarding the prevention of COVID-19 in Chad, in order to propose recommendations that allow communities to better face future health crises. The study was designed as a cross-sectional survey conducted in N'Djamena, Chad, using a convenience sampling technique that included 2,330 participants. A regression model was fitted to assess the relationship between educational level, gender, and health practices regarding COVID-19. 2,269 participants completed the survey successfully. Participants mean age was 31.04, 61.52% were male, and 40.55% had precarious jobs. 21.38% of participants answered right all questions regarding knowledge and 37.19% followed all preventive measures. Findings show that safe practices regarding COVID-19 depend on right knowledge. Gender influences knowledge mainly through its influence on education. Vulnerability is given by women's reduced access to education. The SDH approach provide with an exploratory explanation and some recommendations aimed at local authorities. Access to education for all men and women must be improved to increase health practices and better deal with future health crises.
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    Exploring the Bidirectional Relationship Between Periodontitis and Rheumatoid Arthritis in a Large Danish Cohort
    (2024) Raittio, Eero; Nascimento, Gustavo G.; Lopez, Rodrigo; Baelum, Vibeke
    ObjectiveWe investigated the bidirectional relationship between rheumatoid arthritis (RA) and periodontitis and their cross-sectional association using national administrative health care data.MethodsThe sample included 3,308,903 individuals aged 20 to 79 years who resided in Denmark in 2000 and had remained free of RA and periodontitis in the previous 10 years. RA and periodontitis were defined using diagnosis and treatment codes. Marginal structural survival models were employed to estimate the effects of RA on periodontitis incidence and vice versa from 2000 to 2017. Using a cross-sectional sample of 2,574,536 individuals from 2017, the association of periodontitis with RA was investigated using regression analyses and probabilistic quantitative bias analyses, simulating RA and periodontitis misclassification and unmeasured confounding of smoking.ResultsBetween 2000 and 2017, 20,348 individuals developed RA and 740,799 developed periodontitis. The estimated hazard ratio (HR) for the effect of periodontitis on incident RA was 1.05 (95% confidence interval [CI] 0.88-1.25), resulting in a restricted mean survival time difference of one day. The HR for the effect of RA on incident periodontitis was 0.84 (95% CI 0.80-0.88), corresponding to a restricted mean survival time difference of 151 days. Cross-sectionally, the unadjusted prevalence ratio for the association was 1.15 (95% CI 1.11-1.19), whereas the estimate adjusted for measured and simulated confounding was practically null (0.99, 95% simulation interval 0.93-1.04).ConclusionThese findings challenge previously reported bidirectional relationships between periodontitis and RA, pointing to potential residual confounding as an important link and prompting reconsideration of the biologic plausibility and clinical significance of these associations.
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    Knowledge, Attitudes and Practices Regarding COVID-19 in N'Djamena, Chad
    (SPRINGER, 2021) Takoudjou Dzomo, Guy Rodrigue; Bernales, Margarita; Lopez, Rodrigo; Djofang Kamga, Yves; Kila Roskem, Jean Pierre; Deassal Mondjimbaye, Francis; Nanbolngar, Joseph; Modode, Richard; Rongar, Roger; Diba, Faro; Toglengar, Madjadoum; Ongolo, Jean Pierre; Gomez Virseda, Carlos
    The first African COVID-19 case was reported in Egypt in February 2020. Since then, Sub-Saharan countries have struggled to respond to the pandemic. Among them, Chad is characterized by a high rate of poverty and mortality, a high burden of infectious diseases, insufficient epidemiological surveillance and underdeveloped infrastructure. In this study, we explore the knowledge, attitudes and practices (KAPs) regarding COVID-19 within the Chadian population, to determine whether there are more vulnerable groups of the population that require greater attention from authorities. This study was designed as a cross-sectional survey conducted in N'Djamena, Chad, using a convenience sampling technique that included 2269 participants. The study was conducted in May and August 2020. Questions regarding technical concepts were answered incorrectly by most participants (83.65%). The population had better knowledge about concrete aspects of the pandemics, such as prevention measures and contagion. Regarding attitudes, 34.55% participants were very concerned about the possibility of being infected, 81.27% were unsatisfied/very unsatisfied with their social relationships after the pandemic began, and 68.44% thought that the pandemic was a disturbing/very disturbing issue. As for practices, 49.41% of men followed all preventive measures compared to 32.07% of women, and 3.04% of people with vulnerable jobs did not respect any of preventive measures compared to 1.19% of people without this condition. Gender, job conditions and educational level impact KAPs within the Chadian population. It is suggested that local authorities in Chad should consider these variables when developing health strategies.
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    Molecular and phylogenetic analysis of herpesviruses in endangered free-ranging cervids of Chile: ovine gammaherpesvirus-2-A novel threat to wild and domestic animal health in Chilean Patagonia
    (2024) Hidalgo-Hermoso, Ezequiel; Cabello, Javier; Lopez, Rodrigo; Vergara-Wilson, Vicente; Vera, Frank; Valencia, Carola; Sanchez, Carlos; Celis, Sebastian; Silva, Alejandra; Carinanos, Aintzane; Barria, Ismael; Vicencio, Rocio; Munoz-Leal, Sebastian; Aravena, Paula; Lagos, Rocio; Toro-Letelier, Juan; Verasay-Caviedes, Sebastian; Garnham, Antonio; Pena, Irene; Sanchez, Fernando; Moreira-Arce, Dario; Vergara, Pablo M.; Alegria-Moran, Raul; Cortes-Hinojosa, Galaxia
    Introduction Herpesvirus infections have been highlighted as emerging diseases affecting wildlife health and the conservation of several taxa. Malignant catarrhal fever (MCF) and infectious keratoconjunctivitis (IKC) are two viruses that infect wild ruminants. Nevertheless, epidemiological data on herpesviruses in South American wild ruminants are limited. An outbreak of caprine gammaherpesvirus-2 (CpHV-2) that recently was suspected as the cause of MCF in southern pudus (Pudu puda) prompted the need to conduct molecular screenings in Chilean cervids to understand the epidemiology of herpesviruses. The aim of this study was to determine the occurrence and genetic diversity of herpesviruses in free-ranging cervids from Chile.Methods Herpesvirus infection was assessed in antemortem blood samples (n = 86) from pudus (n = 81) and huemuls (Hippocamelus bisulcus) (n = 5), as well as postmortem samples of spleen (n = 24) and lung (n = 3) from pudus, using a nested pan-herpesvirus PCR assay.Results Combining all suitable sample types, DNA of pudu gammaherpesvirus-1 was detected in five pudues and five huemuls, with an overall prevalence of 9.90% (n = 10/101; 95% CI = 5.11-17.87%). One pudu tested positive for ovine gammaherpesvirus-2 (n = 1/96; 1.04%; 95% CI = 0.05-6.49%), and one pudu tested positive for a Macavirus sequence with 98.63 similarity to ovine gammaherpesvirus-2 (n = 96; 1.04%; 95% CI = 0.05-6.49%).Discussion To the best of our knowledge, this is the first report of a herpesvirus in huemul and of ovine gammaherpesvirus-2 in Chile. Our results also confirm the active circulation of herpesvirus in free-ranging cervids in Chilean Patagonia, and as such, MCF should be considered as a possible cause of disease in free-ranging Chilean pudus and livestock species. Further research is necessary to develop a plan of systematic monitoring (serological and pathological screening) of herpesviruses in Chilean wild and domestic ruminants to understand their diversity and impact on animal health and conservation.
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    Multi-Agent Path Finding: A New Boolean Encoding
    (2022) Asin Acha, Roberto; Lopez, Rodrigo; Hagedorn, Sebastian; Baier, Jorge A.
    Multi-agent pathfinding (MAPF) is an NP-hard problem. As such, dense maps may be very hard to solve optimally. In such scenarios, compilation-based approaches, via Boolean satisfiability (SAT) and answer set programming (ASP), have been shown to outperform heuristic-search-based approaches, such as conflict-based search (CBS). In this paper, we propose a new Boolean encoding for MAPF, and show how to implement it in ASP and MaxSAT. A feature that distinguishes our encoding from existing ones is that swap and follow conflicts are encoded using binary clauses, which can be exploited by current conflict -driven clause learning (CDCL) solvers. In addition, the number of clauses used to encode swap and follow conflicts do not depend on the number of agents, allowing us to scale better. For MaxSAT, we study different ways in which we may combine the MSU3 and LSU algorithms for maximum performance. In our experimental evaluation, we used square grids, ranging from 20 x 20 to 50 x 50 cells, and warehouse maps, with a varying number of agents and obstacles. We compared against representative solvers of the state-of-the-art, including the search-based algorithm CBS, the ASP-based solver ASP-MAPF, and the branch-and-cut-and-price hybrid solver, BCP. We observe that the ASP implementation of our encoding, ASP-MAPF2 outperforms other solvers in most of our experiments. The MaxSAT implementation of our encoding, MtMS shows best performance in relatively small warehouse maps when the number of agents is large, which are the instances with closer resemblance to hard puzzle-like problems.
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    Periodontitis is associated with impaired olfactory function: A clinical study
    (2024) Cassiano, Luisa Schertel; Jensen, Anne Birkeholm; Pajaniaye, Julie; Lopez, Rodrigo; Fjaeldstad, Alexander Wieck; Nascimento, Gustavo G.
    AimTo explore the association between periodontitis and olfactory disorders.MethodsClinical data were collected from 198 individuals between the ages of 18 and 60 years living in Denmark. The exposure was periodontitis, and the outcome was olfactory function (Threshold, Discrimination, Identification - TDI score), both measured clinically. Covariates included sex, age, education level, income, usage of nasal spray, tongue coating, halitosis, xerostomia, smoking, and history of COVID-19. Structural equation modeling was used to estimate the association between periodontitis and olfactory function. Periodontitis was defined using the AAP/EFP classification and dichotomized into "no" (healthy subjects) and "yes" (Stages I, II, and III). Olfactory function was treated as a one-factor latent variable, including the different olfactory scores. In addition, extra models were performed considering each olfactory component as a separate outcome and the TDI Global Score.ResultsThe results showed that periodontitis was associated with a lower olfactory function [standardized coefficient (SC) -0.264, 95% CI -0.401, -0.118]. Additionally, periodontitis was also associated with a lower olfactory Threshold (odorant concentration required for detection) (SC -0.207, 95% CI -0.325, -0.089), Discrimination (ability to discriminate between odorants) (SC -0.149, 95% CI -0.270, -0.027), Identification (ability to identify odorants) scores (SC -0.161, 95% CI -0.277, -0.045), and TDI Global Score (SC -0.234, 95% CI -0.370, -0.099).ConclusionsThis study suggests that periodontitis is associated with olfactory impairment.
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    Psychosocial Distress and Periodontitis in Adolescents
    (2012) Lopez, Rodrigo; Ramirez, Valeria; Marro, Patricio; Baelum, Vibeke
    Purpose: To assess whether adolescents with periodontitis presented with higher scores for non-psychotic psychosocial disorders than control subjects without periodontitis.
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    Self-reported periodontitis association with impaired smell and taste: A multicenter survey
    (2024) Cassiano, Luisa Schertel; Ribeiro, Ana Paula; Peres, Marco Anselmo; Lopez, Rodrigo; Fjaeldstad, Alexander; Marchini, Leonardo; Nascimento, Gustavo G.
    Objectives To investigate the association between self-reported periodontitis and the senses of taste and smell among employees of one Danish and two American universities.Materials and Methods Data were collected through a digital survey. A total of 1239 individuals from Aarhus University - Denmark, the University of Iowa, and the University of Florida - USA were included. Self-reported periodontitis was the exposure. The perceived senses of taste and smell were the outcomes and were measured through a visual analog scale (VAS). Self-perceived halitosis was the mediator. Confounders were age, sex, income, education, xerostomia, COVID-19, smoking, body mass index, and diabetes. The total effect was decomposed into direct and indirect using a counterfactual approach.Results The total effect of periodontitis on an impaired sense of taste was OR 1.56 (95% CI [1.02, 2.09]), of which 23% was mediated by halitosis (OR 1.13; 95% CI [1.03, 1.22]). Additionally, individuals with self-reported periodontitis had a 53% higher chance of having impaired smell (OR 1.53; 95% CI [1.00, 2.04]), with halitosis mediating 21% of the total effect (OR 1.11; 95% CI [1.02, 1.20]).Conclusion Our findings suggest that periodontitis is associated with distorted senses of taste and smell. Additionally, this association appears to be mediated by halitosis.