Isolation and phenotypic characterization of cancer stem cells from metastatic oral cancer cells.

OBJECTIVES: To isolate cancer stem cells (CSC) from a metastatic oral squamous cell carcinoma (OSCC) cell line and investigate their in vitro and in vivo phenotypic characteristics. MATERIALS AND METHODS: Subpopulations with individual staining intensities for CD44 and CD326 were isolated from the OSCC cell line LN-1A by FACS: CD44Low/CD326- (CSC-M1), CD44Low/CD326High (CSC-E), and CD44High/CD326- (CSC-M2). Proliferation, clonogenic potential, adhesion, migration, epithelial-mesenchymal transition markers, and sensitivity to cisplatin and TVB-3166 were analyzed in vitro. Tumor formation and metastasis were assessed by subcutaneous and orthotopic inoculations into BALB/c mice. RESULTS: E-cadherin levels were higher in CSC-E cells while vimentin and Slug more produced by CSC-M2 cells. CSC-M1 and CSC-M2 subpopulations showed higher proliferation, produced more colonies, and have stronger adhesion to the extracellular matrix. All cell lines established tumors; however, CSC-E and CSC-M2 formed larger masses and produced more metastases. CONCLUSION: The CSC subpopulations here described show increased cancer capabilities in vitro, tumorigenic and metastatic potential in vivo, and may be exploited in the search for novel therapeutic targets for OSCC.

Age-related Morphofunctional Changes in Sickle Cell Mice Bone Marrow Mesenchymal Stromal Cells.

BACKGROUND AND OBJECTIVES: Bone marrow mesenchymal stromal cells (BM-MSCs) are key elements of the hematopoietic niche and participate in the regulatory mechanisms of hematopoietic stem cells (HSCs). Hematological diseases can affect MSCs and their functions. However, the dysregulations caused by sickle cell disease (SCD) are not fully elucidated. This work explored changes in BM-MSCs and their relationship with age using sickle cell mice (Townes-SS). MATERIALS AND METHODS: BM-MSCs were isolated from Townes-SS, and control groups 30- and 60-day-old Townes-AA and C57BL/6 J. RESULTS: The BM-MSCs showed no morphological differences in culture and demonstrated a murine MSC-like immunophenotypic profile (Sca-1+, CD29+, CD44+, CD90.2+, CD31-, CD45-, and CD117-). Subsequently, all BM-MSCs were able to differentiate into adipocytes and osteocytes in vitro. Finally, 30-day-old BM-MSCs of Townes-SS showed higher expression of genes related to the maintenance of HSCs (Cxcl12, Vegfa, and Angpt1) and lower expression of pro-inflammatory genes (Tnfa and Il-6). However, 60-day-old BM-MSCs of Townes-SS started to show expression of genes related to reduced HSC maintenance and increased expression of pro-inflammatory genes. CONCLUSION: These results indicates age as a modifying factor of gene expression of BM-MSCs in the context of SCD.

Pesticide water variability and prioritization: The first steps towards improving water management strategies in irrigation hydro-agriculture areas.

The presence of pesticides in aquatic ecosystems poses significant risks to non-target organisms, necessitating monitoring and environmental risk assessment. This study aimed to evaluate the dynamics and environmental risk of pesticides in a hydro-agricultural area with intensive agricultural practices, in the Mediterranean region (South of Portugal). Seasonality and location influenced pesticide numbers and concentrations, with the highest levels observed during the dry season. Triazines, phenylureas, and organophosphates were the predominant pesticide classes, with terbuthylazine, bentazone, terbutryn, diazinon, and metolachlor exhibiting the highest detection frequencies (68 % to 72 %). Notably, 44 % of the quantified pesticides are no longer authorized in Portugal, with 33 % posing a high environmental risk. Some insecticides, including imidacloprid, methiocarb, and malathion, were occasionally detected at concentrations that posed high risks to the aquatic ecosystem (RQ ≥ 1). Irgarol, an algicide used in irrigation canals, presented a high risk in 91 % of the analysed samples. The study's distribution profile of pesticides revealed a significant transportation of these compounds from reservoirs to irrigation hydrants, establishing them as a secondary source of crop and environmental contamination. Additionally, the assessment of spatial distribution and environmental risk allowed for the identification of specific pollutants in different locations, prioritizing them based on their ecotoxicological risk to aquatic ecosystems. These findings reinforce the importance of implementing management measures at the level of hydro-agricultural areas, helping to stop the cycle of pesticide contamination. Only this type of strategy will make it possible to protect water quality, biodiversity and the health of citizens, contributing to the European Union's objectives of improving the condition of freshwater bodies and promoting the sustainable use of pesticides.

From Passion to Abyss: The Mental Health of Athletes during COVID-19 Lockdown.

The outbreak and pandemic of COVID-19 forced people into extreme isolation and social distancing, with significant limitations on various activity sectors, including sports. This study aimed to assess the psychological health status of athletes during sports lockdown. Additionally, we intend to verify the mediating role of sleep disorders in stress perception and subjective happiness. Our sample was composed of 1492 Portuguese athletes from eight different team sports. During sports lockdown, athletes were found to have high stress levels and low subjective happiness levels and experience sleep disorders. Finally, these results conclude that sports lockdowns harm athletes' psychological health and well-being. Pay cuts to athletes are an extra stress factor that exacerbate these adverse effects on psychological health. Finally, sleep is a mediator variable between stress perception and subjective happiness levels. This study's significant contributions, limitations, and future directions are discussed in the conclusion.

Development of QuEChERS-based multiresidue analytical methods to determine pesticides in corn, grapes and alfalfa.

Analytical methods based on QuEChERS and liquid chromatography-tandem mass spectrometry were developed for the determination of 42 polar and semi-polar pesticides in three representative vegetable matrices, viz. corn, grapes and alfalfa. A 26-2 fractional factorial experimental design was used to cost-effectively optimize the extraction procedure. The optimal analytical approaches were validated in terms of linearity, sensitivity, trueness, and precision. Most of the target pesticides showed a relative recovery of 70-120 %. Moreover, limits of detection (between 0.01 ng/g and 20 ng/g) were below the maximum residue levels set for the target analytes in nearly all cases. Analysis of real samples showed the presence of five pesticides in grapes and alfalfa at concentrations between the method LOQs and 40 ng/g. To the authors' knowledge, these methods are the first ever described for the determination of 6, 13 and 24 of the 42 target pesticides measured in corn, grapes and alfalfa, respectively.

Integrative toolbox to assess the quality of freshwater sediments contaminated with potentially toxic metals.

The Guadiana Basin is a transnational basin, presenting historical contamination with potentially toxic metals (PTM), which origin can be both natural and anthropogenic. This study explores the use of a set of observational, chemical and ecotoxicological assays with Heterocypris incongruens, Vibrio fischeri, Pseudokirchneriella subcapitata, Thamnocephalus platyurus, identifying the most sensitive to be included in a toolbox to analyze the quality of freshwater sediments related to this type of contamination. The study included the analysis of a reservoir and streams sediments of Guadiana basin, in two consecutive years with different climate conditions 2017 (dry year) and 2018 (normal year). The results showed high chemical variability along the basin, with greater contamination with PTM in the reservoir sediments. The calculated Enrichment Factors (EF) indicated high anthropogenic contamination by Cd, followed by Pb (EF > 1.5). The geoaccumulation index (Igeo) revealed that the sediments were severely polluted with Cd, and slightly polluted with Pb and Cu, inducing a higher sublethal toxicity to Heterocypris incongruens. Among the parameters evaluated, and after the use of multivariate statistical techniques, the toolbox for assessing sediments quality, in similar climate and geological conditions, should include the analysis of: meteorology, land use/cover in the area, granulometry, organic matter content, PTM concentrations, contamination indices (e.g., Igeo and EF), and sublethal bioassays with H. incongruens (total sediment analysis) and Vibrio fisheri luminescence inhibition (pore water analysis).

Philadelphia-negative myeloproliferative neoplasms display alterations in monocyte subpopulations frequency and immunophenotype.

Philadelphia-negative myeloproliferative neoplasms (MPN) are clonal hematological diseases associated with driver mutations in JAK2, CALR, and MPL genes. Moreover, several evidence suggests that chronic inflammation and alterations in stromal and immune cells may contribute to MPN's pathophysiology. We evaluated the frequency and the immunophenotype of peripheral blood monocyte subpopulations in patients with polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (MF). Peripheral blood monocytes from PV (n = 16), ET (n = 16), and MF (n = 15) patients and healthy donors (n = 10) were isolated and submitted to immunophenotyping to determine the frequency of monocyte subpopulations and surface markers expression density. Plasma samples were used to measure the levels of soluble CD163, a biomarker of monocyte activity. PV, ET, and MF patients presented increased frequency of intermediate and non-classical monocytes and reduced frequency of classical monocytes compared to controls. Positivity for JAK2 mutation was significantly associated with the percentage of intermediate monocytes. PV, ET, and MF patients presented high-activated monocytes, evidenced by higher HLA-DR expression and increased soluble CD163 levels. The three MPN categories presented increased frequency of CD56+ aberrant monocytes, and PV and ET patients presented reduced frequency of CD80/86+ monocytes. Therefore, alterations in monocyte subpopulations frequency and surface markers expression pattern may contribute to oncoinflammation and may be associated with the pathophysiology of MPN.

Covid-19, the Chinese diaspora, and the enduring legacy of racism in Peru.

The coronavirus pandemic has exposed a global tendency throughout history to blame immigrants for propagating epidemics. Chinese individuals were thus targeted during past public health crises in Peru, but during the current coronavirus pandemic racist notions painting people of Chinese descent as "agents of contagion" diminished significantly. Here we examine three major epidemics (yellow fever, the bubonic plague, and covid-19) to demonstrate the current and somewhat surprising shift in negative attitudes toward the Chinese community. Peruvians' refusal to embrace derogatory terms (the "Chinese virus") or target individuals of Asian descent constitutes an intriguing case at a moment when xenophobic discourse is rampant in the Western hemisphere.

Covid-19, the Chinese diaspora, and the enduring legacy of racism in Peru / Covid-19, a diáspora chinesa e o legado duradouro do racismo no Peru

Abstract The coronavirus pandemic has exposed a global tendency throughout history to blame immigrants for propagating epidemics. Chinese individuals were thus targeted during past public health crises in Peru, but during the current coronavirus pandemic racist notions painting people of Chinese descent as "agents of contagion" diminished significantly. Here we examine three major epidemics (yellow fever, the bubonic plague, and covid-19) to demonstrate the current and somewhat surprising shift in negative attitudes toward the Chinese community. Peruvians' refusal to embrace derogatory terms (the "Chinese virus") or target individuals of Asian descent constitutes an intriguing case at a moment when xenophobic discourse is rampant in the Western hemisphere.

Resumo A pandemia do coronavírus expôs uma tendência mundial ao longo da história de culpar imigrantes pela propagação de epidemias. No Peru, os chineses sofreram preconceito racial durante crises de saúde pública anteriores. Surpreendentemente, a ideia de que os descendentes de chineses são "agentes de contágio" diminuiu significativamente durante a atual pandemia. Examinaremos aqui três grandes epidemias (febre amarela, peste bubônica e covid-19), a fim de demonstrar a atual mudança nas atitudes negativas em relação à comunidade chinesa. A recusa dos peruanos de adotar termos depreciativos (o "vírus chinês") ou visar indivíduos de ascendência asiática é algo intrigante em tempos de completa disseminação de discurso xenofóbico no hemisfério ocidental.

Allogeneic haematopoietic stem cell transplantation resets T- and B-cell compartments in sickle cell disease patients.

Objectives: Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is the only currently available curative treatment for sickle cell disease (SCD). Here, we comprehensively evaluated the reconstitution of T- and B-cell compartments in 29 SCD patients treated with allo-HSCT and how it correlated with the development of acute graft-versus-host disease (aGvHD). Methods: T-cell neogenesis was assessed by quantification of signal-joint and ß-chain TCR excision circles. B-cell neogenesis was evaluated by quantification of signal-joint and coding-joint K-chain recombination excision circles. T- and B-cell peripheral subset numbers were assessed by flow cytometry. Results: Before allo-HSCT (baseline), T-cell neogenesis was normal in SCD patients compared with age-, gender- and ethnicity-matched healthy controls. Following allo-HSCT, T-cell neogenesis declined but was fully restored to healthy control levels at one year post-transplantation. Peripheral T-cell subset counts were fully restored only at 24 months post-transplantation. Occurrence of acute graft-versus-host disease (aGvHD) transiently affected T- and B-cell neogenesis and overall reconstitution of T- and B-cell peripheral subsets. B-cell neogenesis was significantly higher in SCD patients at baseline than in healthy controls, remaining high throughout the follow-up after allo-HSCT. Notably, after transplantation SCD patients showed increased frequencies of IL-10-producing B-regulatory cells and IgM+ memory B-cell subsets compared with baseline levels and with healthy controls. Conclusion: Our findings revealed that the T- and B-cell compartments were normally reconstituted in SCD patients after allo-HSCT. In addition, the increase of IL-10-producing B-regulatory cells may contribute to improve immune regulation and homeostasis after transplantation.

QuEChERS-based analytical methods developed for LC-MS/MS multiresidue determination of pesticides in representative crop fatty matrices: Olives and sunflower seeds.

Oilseed crops are greatly extended all over the world. Their high fat content can interfere during pesticide multiresidue analysis through liquid chromatography-tandem mass spectrometry (LC-MS/MS). This work aimed at overcoming this issue by developing and validating two QuEChERS-based methods for LC-MS/MS determination of 42 pesticides in two fatty food matrices: olives and sunflower seeds. Optimization of the extraction method was achieved following a 26-2 fractional factorial design in a highly cost-effective way. Validation of the multi-residue methods demonstrated improved limits of detection, below the established maximum residue levels (MRLs) for almost all compounds, good precision, and trueness, in compliance with SANTE guidelines. Application of these methods to the analysis of real samples from the Iberian Peninsula showed the presence of some pesticides of relevant environmental concern, including four compounds contained in the Pesticide Action Network International list of highly hazardous pesticides, found at levels between 0.03 ng/g and 104 ng/g.

Long-Term Effects of Allogeneic Hematopoietic Stem Cell Transplantation on Systemic Inflammation in Sickle Cell Disease Patients.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only currently available curative treatment for sickle cell disease (SCD). However, the effects of HSCT on SCD pathophysiology are poorly elucidated. Here, we assessed red blood cell (RBC) adhesiveness, intensity of hemolysis, vascular tone markers and systemic inflammation, in SCD patients treated with allogeneic HSCT. Thirty-two SCD patients were evaluated before and on long-term follow-up after HSCT. Overall survival was 94% with no severe (grade III-IV) graft-vs-host disease and a 22% rejection rate (graft failure). Hematological parameters, reticulocyte counts, and levels of lactate dehydrogenase (LDH), endothelin-1 and VCAM-1 normalized in SCD patients post-HSCT. Expression of adhesion molecules on reticulocytes and RBC was lower in patients with sustained engraftment. Levels of IL-18, IL-15 and LDH were higher in patients that developed graft failure. Increased levels of plasma pro-inflammatory cytokines, mainly TNF-α, were found in SCD patients long-term after transplantation. SCD patients with sustained engraftment after allo-HSCT showed decreased reticulocyte counts and adhesiveness, diminished hemolysis, and lower levels of vascular tonus markers. Nevertheless, systemic inflammation persists for at least five years after transplantation, indicating that allo-HSCT does not equally affect all aspects of SCD pathophysiology.

Clima organizacional en el personal de enfermería en una unidad de cuidados intensivos / Organizational environment in nursing staff in an intensive care unit

Introducción: el sistema organizacional genera un determinado clima de trabajo que repercute en las motivaciones de los miembros de la organización y en su comportamiento, por lo que al evaluar el clima organizacional se mide la forma como es percibida la organización. Objetivo: identificar el clima organizacional en el personal de enfermería de la unidad de cuidados intensivos (UCI) del Hospital de Especialidades (HE) No. 14 del Instituto Mexicano del Seguro Social (IMSS), en Veracruz, México. Metodología: estudio observacional, descriptivo y transversal, en el que participaron 49 enfermeras de los turnos matutino, vespertino y nocturno de la UCI del HE No. 14. Durante junio y julio de 2019, se aplicó el instrumento Clima Organizacional de Litwin y Stringer, que contiene 53 ítems en sus 9 dimensiones. Resultados: el nivel promedio global del clima organizacional en la UCI fue de 26.4, lo que lleva a categorizarlo como bueno. Las dimensiones: recompensa, estándares y conflicto obtuvieron una puntuación de 23.5 a 24.8, que se traduce como un promedio regular del clima organizacional. Conclusiones: hay un clima organizacional bueno en el personal de enfermería. El componente que influye de manera positiva es la dimensión cooperación, ya que el trabajador empatiza con sus compañeros de servicio. La dimensión conflicto influye de manera negativa, pues abarca la falta de motivación del personal para realizar su trabajo.

Introduction: Organizational systems generate certain workplace environment that affects the staff members' motivation and their behavior, which is why assessing the organizational environment allows to measure the staff perception on the organization. Objective: To identify the organizational environment of the nursing staff at the Specialty Hospital (SH) No. 14 intensive care unit (ICU) of the National Institute for Social Security (Instituto Mexicano del Seguro Social), in Veracruz, Mexico. Methods: Observational, descriptive, and cross-sectional study, which included 49 nurses from the morning, afternoon and night shifts of the aforementioned ICU. During June and July 2019, it was administered the instrument Organizational Climate by Litwin and Stringer, which contains 53 items in its 9 dimensions. Results: The global average level of the organizational environment in the ICU was 26.4, which leads to categorize it as good. The dimensions reward, standards and conflict obtained a range from 23.5 to 24.8, i.e., a regular average of the organizational environment. Conclusions: There is an organizational environment classified as good in the nursing staff. The component that has a positive influence is the cooperation dimension, since the worker empathizes with his fellow employees. The conflict dimension has a negative influence, given that it includes the lack of motivation of the staff to carry out their work.

Persisting Salivary IgG Against SARS-CoV-2 at 9 Months After Mild COVID-19: A Complementary Approach to Population Surveys.

BACKGROUND: Declining humoral immunity in coronavirus disease 2019 (COVID-19) patients and possible reinfection have raised concern. Mucosal immunity, particularly salivary antibodies, may be short lived although long-term studies are lacking. METHODS: Using a multiplex bead-based array platform, we investigated antibodies specific to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins in 256 saliva samples from convalescent patients 1-9 months after symptomatic COVID-19 (n = 74, cohort 1), undiagnosed individuals with self-reported questionnaires (n = 147, cohort 2), and individuals sampled prepandemic (n = 35, cohort 3). RESULTS: Salivary IgG antibody responses in cohort 1 (mainly mild COVID-19) were detectable up to 9 months postrecovery, with high correlations between spike and nucleocapsid specificity. At 9 months, IgG remained in blood and saliva in most patients. Salivary IgA was rarely detected at this time point. In cohort 2, salivary IgG and IgA responses were significantly associated with recent history of COVID-19-like symptoms. Salivary IgG tolerated temperature and detergent pretreatments. CONCLUSIONS: Unlike SARS-CoV-2 salivary IgA that appeared short lived, specific saliva IgG appeared stable even after mild COVID-19, as for blood serology. This noninvasive saliva-based SARS-CoV-2 antibody test with home self-collection may be a complementary alternative to conventional blood serology.

[Digital archives for historians: research during the pandemic]. / Archivos digitales para historiadores: investigar en tiempos de pandemia.

This article aims to provide researchers and students with information on digital archives in libraries in Latin America and elsewhere. It is aimed at those interested in health history, focusing on Peru and Chile.

Este artículo tiene como propósito poner al alcance de investigadores y estudiantes información sobre archivos digitales de bibliotecas en América Latina y en el extranjero. Su contenido está orientado para aquellos interesados en historia de la salud, con énfasis en Perú y Chile.

Archivos digitales para historiadores: investigar en tiempos de pandemia / Digital archives for historians: research during the pandemic

Resumen Este artículo tiene como propósito poner al alcance de investigadores y estudiantes información sobre archivos digitales de bibliotecas en América Latina y en el extranjero. Su contenido está orientado para aquellos interesados en historia de la salud, con énfasis en Perú y Chile.

Abstract This article aims to provide researchers and students with information on digital archives in libraries in Latin America and elsewhere. It is aimed at those interested in health history, focusing on Peru and Chile.

Epidemias en los márgenes: la peste bubónica (1903-1905) y el covid-19 en el sur andino peruano / Epidemics on the Margins: The Bubonic Plague (1903­1905) and covid-19 Epidemics in the Peruvian South Andean Region / Epidemias marginais: a peste bubônica (1903-1905) e covid-19 no sul andino peruano

Introducción: la epidemia de covid-19 ha dejado en evidencia una serie de problemas de desigualdad en el acceso a la salud pública en Perú, especialmente en las provincias alejadas de la capital, donde se observa precariedad tanto en infraestructura como en personal sanitario. Este artículo analiza cómo el Gobierno y la población han hecho frente a epidemias en el sur de Perú, usando como casos de estudio el covid-19 y la peste bubónica ocurrida en 1903 y 1905, con el fin de entender continuidades en el manejo de la crisis epidémica y su respuesta a ellas. Desarrollo: se estudia la epidemia de la peste bubónica en las ciudades de Arequipa y Mollendo en 1903 y 1905 y el covid-19, con un enfoque en el funcionamiento del sistema de salud local y nacional, en la infraestructura sanitaria disponible para enfrentar epidemias y, finalmente, en las respuestas sociales de la población respecto al escepticismo de las medidas impuestas por las autoridades y al incremento de la automedicación. Conclusiones: la epidemia del covid-19 en el sur de Perú presenta importantes similitudes con la epidemia de peste bubónica que afectó a la región a inicios del siglo xx: desorden de responsabilidades, falta de previsión para hacer frente a enfermedades epidémicas, infraestructura precaria y una población con alto grado de desconfianza frente a las recomendaciones de las autoridades civiles y sanitarias

Introduction: The covid-19 epidemic has revealed a series of inequality problems in the access to public health services in Peru, especially in provinces far from the capital where precariousness in both infra-structure and sanitary personnel is observed. In this study, we analyzed how the population and author-ities in southern Peru faced epidemics, using covid-19 epidemic and bubonic plague in 1903 and 1905 as case studies to understand continuities in the management of epidemic crises and social response to them. Development: We studied the bubonic plague epidemic in the cities of Arequipa and Mollendo in 1903 and 1905 as well as the covid-19 epidemic, focusing on the functioning of local and national health systems, health infrastructure available to face epidemics, and finally, the social response of the population, paying particular attention to the skepticism of the population toward measures imposed by the authorities and increase in self-medication. Conclusions: The covid-19 epidemic in southern Peru pres-ents important similarities with the bubonic plague epidemic that affected the region at the beginning of the 20th century, including a disorder of responsibilities, lack of foresight to face epidemic diseases, insufficient infrastructure, and a population with a high degree of distrust in the recommendations given by the civil and health authorities

Introdução: a epidemia de covid-19 expôs uma série de problemas de desigualdade no acesso à saúde pública no Peru, especialmente nas províncias distantes da capital onde há precariedade tanto de infraestrutura quanto de pessoal de saúde. Este artigo analisa como o governo e a população têm enfren-tado epidemias no sul do Peru, utilizando o covid-19 e a peste bubônica ocorrida em 1903 e 1905 como estudos de caso, a fim de compreender as continuidades na gestão da crise epidêmica e suas respostas. Desenvolvimento: são estudadas as epidemias de peste bubônica nas cidades de Arequipa e Mollendo em 1903 e 1905 e a covid-19, enfocando no funcionamento do sistema de saúde local e nacional, a infraes-trutura de saúde disponível para enfrentar as epidemias e, por fim, as respostas da população, com particular atenção para o ceticismo em relação às medidas impostas pelas autoridades e ao aumento da automedicação. Conclusões: a epidemia de covid-19 no sul do Peru apresenta semelhanças importantes com a epidemia de peste bubônica que afetou a região no início do século XX: desordem de responsabili-dades, falta de previsão para enfrentar as doenças epidêmicas, infraestrutura precária e uma população com alto grau de desconfiança em relação às recomendações das autoridades civis e sanitárias

Oral Health Among Swedish Patients with Substance Use Disorders - A Comparative, Cross-Sectional Study.

PURPOSE: This study explored the oral health of individuals with substance use disorders and examined the relationship between oral health and type and number of years of substance use disorder. MATERIALS AND METHODS: This comparative cross-sectional study comprised patients with one of four groups of substance use disorders - alcohol, cannabis, central nervous system stimulants (CNSS), and opiates. All participants underwent a dental examination and were included in the study based on their clinical findings. RESULTS: Of 95 participants, 79 (83%) were male and 37 (39%) were homeless. Statistically significant difference between the groups was observed in 6-12-mm periodontal pocket depths (p <0.05), as were differences in oral mucosal changes (p <0.001). Statistically significantly lower proportions were observed in the cannabis group for Mob G:0 and Mob G:1 and Furcation G:1 compared to the CNSS and opiate groups; the proportion of Furcation G:0 was significantly lower in the alcohol group compared to the cannabis group. Analysis of variance (ANOVA) revealed statistically significant between-group differences in age, number of years of substance use disorder, number of teeth, and decayed, missing and filled teeth (DMFT). When controlling for age and gender, substance type was found to be a statistically significant predictor of number of teeth (B = -4.4; 95% CI: -8.1 to -0.38; p = 0.03) and DMFT (B = 2.1; 95% CI: 0.86 to 3.3; p = 0.001). CONCLUSIONS: These results indicate poor oral health among individuals with substance use disorders. It seems that oral health problems are lower among abusers of cannabis than of CNSS, alcohol and opiates.