Rich but random: parasite communities of snouted treefrog, Scinax fuscovarius (Anura: Hylidae), in Bodoquena Mountains, western Brazil.

Hosts represent discrete habitats that contain finite parasite communities, and individual hosts can be used as replicates in parasitism studies, such as investigations of the processes that mediate the formation of parasite communities. However, within a single host population, there may be singularities among individuals that affect parasite contact rates. Accordingly, the goals of the present study were to document the parasites associated with the small treefrog Scinax fuscovarius, to verify possible variation and co-occurrences in parasite infracommunities, and to assess the effects of host characteristics (size and sex) on infracommunity structure. Treefrog specimens (n = 75) were collected from the Bodoquena Mountains in Mato Grosso do Sul, Brazil. After collection, the specimens were transported to the laboratory, and examined for parasitic. The parasites found were removed, fixed, and identified. Patterns in parasite infracommunity organization were analyzed using the checkerboard score index, which was calculated using a presence-absence matrix. The matrix was randomized under the null hypothesis that the infracommunities independently represent the component community. Forty-two (56%) of the individuals harbored at least one parasite, and a total of 500 metazoan parasites were recovered, with a particularly rich composite community of 18 taxa, including 13 nematodes, two trematodes, one cestode, one oligochaete, and one mite larvae. The parasite species were randomly distributed among the infracommunities, with no evidence of co-occurrence, segregation, or aggregation. However, both body size and sex influenced infection, with larger hosts harboring more parasites and parasites were more abundant in male specimens and more species rich in female specimens. These results suggest that the parasite infracommunities of S. fuscovarius are shaped by both random factors and individual host characteristics.

Ecological factors associated with areas of high tuberculosis diagnosis delay.

OBJECTIVE: We aimed to identify areas of high tuberculosis (TB) diagnosis delay in mainland Portugal in 2017 and ecological factors associated with these areas. STUDY DESIGN: This was an ecological study. METHODS: We considered all notified pulmonary TB cases from the Portuguese National Tuberculosis Surveillance System in mainland Portugal. Diagnostic delays were calculated at the municipality level. Demographic variables, proxies for TB awareness, health services capacity indicators, and socio-economic variables were included and extracted from official databases, such as Statistics Portugal, Ministeries, Foreigners and Border Services. We used spatial analysis to identify areas of high delay in 2017 and logistic generalised additive models to identify ecological factors associated with the identified cluster. RESULTS: We identified an area of high delay in 2017 in the South region of the country. Overall, municipalities with a smaller population density, smaller proportion of unemployed, fewer health centres and higher old-age dependency ratio, proportion of men, TB incidence, proportion of immigrants and high school dropout had a higher probability of belonging in a high delay area. CONCLUSION: The role of primary health care in TB diagnosis should be further explored. Interventions should address factors interplaying at the local and individual levels. Policies influencing social and health conditions, leading to changes in individual behaviour, can lead to sustained improvements over time.

Non-adherence to COVID-19 lockdown: who are they? A cross-sectional study in Portugal.

OBJECTIVES: The SARS-CoV-2 virus has spread worldwide, leading governments to implement mitigation measures. Understanding the reluctance to adhere to non-pharmacological interventions might help promote adherence to these measures. This study aimed to identify factors associated with non-adherence to the first lockdown in Portugal. STUDY DESIGN: Cross-sectional study. METHODS: This study used data from a Portuguese community-based survey entitled 'COVID-19 Barometer: Social Opinion'. Data were collected on risk perception, health status and social experiences using a snowball sampling technique. The event of interest corresponded to participants who reported not staying home during the lockdown period, serving as a proxy for non-adherence to lockdown. Logistic regression was used to identify factors associated with non-adherence to the first lockdown. RESULTS: Responses from 133,601 individual questionnaires that were completed during the first week of the first lockdown in 2020 were analysed. A minority of participants (5.6%) reported non-adherence to lockdown (i.e. leaving home for reasons other than essential situations). Working in the workplace was the factor with the strongest association of non-adherence to the lockdown. Several other factors were also associated with non-adherence to the first lockdown; namely, being a man, being a student, having a low level of education, having a low income, living alone or with a high-infection-risk professional (e.g. doctor, nurse, pharmaceutical, health technician, firefighter, police officer, military, essential services worker), perceiving the risk of getting COVID-19 to be high, not having social support in case of infection, feeling agitated, sad or anxious every day, and considering the preventive measures to be unimportant or inadequate. CONCLUSIONS: Non-adherence to lockdown was associated with socio-economic, trust and perception factors. Future research should investigate the mechanisms underlying these associations to help identify the population groups who are most at risk of non-adherence.

Effects of bilateral lung transplantation on cardiac autonomic modulation and cardiorespiratory coupling: a prospective study.

BACKGROUND: Although cardiac autonomic modulation has been studied in several respiratory diseases, the evidence is limited on lung transplantation, particularly on its acute and chronic effects. Thus, we aimed to evaluate cardiac autonomic modulation before and after bilateral lung transplantation (BLT) through a prospective study on patients enrolled while awaiting transplant. METHODS: Twenty-two patients on the waiting list for lung transplantation (11 women, age 33 [24-51] years) were enrolled in a prospective study at Ospedale Maggiore Policlinico Hospital in Milan, Italy. To evaluate cardiac autonomic modulation, ten minutes ECG and respiration were recorded at different time points before (T0) and 15 days (T1) and 6 months (T2) after bilateral lung transplantation. As to the analysis of cardiac autonomic modulation, heart rate variability (HRV) was assessed using spectral and symbolic analysis. Entropy-derived measures were used to evaluate complexity of cardiac autonomic modulation. Comparisons of autonomic indices at different time points were performed. RESULTS: BLT reduced HRV total power, HRV complexity and vagal modulation, while it increased sympathetic modulation in the acute phase (T1) compared to baseline (T0). The HRV alterations remained stable after 6 months (T2). CONCLUSION: BLT reduced global variability and complexity of cardiac autonomic modulation in acute phases, and these alterations remain stable after 6 months from surgery. After BLT, a sympathetic predominance and a vagal withdrawal could be a characteristic autonomic pattern in this population.

Correlation of molecular data with histopathological and clinical features in a series of 66 patients with medullary thyroid carcinoma.

PURPOSE: Medullary thyroid carcinoma (MTC) displays a wide variety of histopathological features, and several histological variants have been described. In follicular cell-derived thyroid carcinomas, there is a good correlation between genotype and phenotype. In this study, we investigated whether such a correlation is also present in MTC. METHODS: The histopathological features were evaluated in a series of 66 molecularly characterised tumours and correlated with the clinical characteristics. RESULTS: Most MTC exhibited the classical variant (83.3%). Other variants included spindle cell (6.1%), pseudopapillary (4.5%), paraganglioma-like (3.0%), angiosarcoma-like (1.5%), and oncocytic follicular (1.5%). Tumours were classified into four groups: group 1, with somatic p.Met918Thr and p.Ala883Phe RET mutations; group 2, with other RET mutations; group 3, with RAS mutations; and group 4, without RET or RAS mutations. Tumours from groups 1 and 4 were typically associated with the classical variant, with abundant fibrosis, lymphovascular invasion, extrathyroidal extension, and more advanced stages of disease, whereas group 2 included histological variants other than the classical variant (namely, pseudopapillary and paraganglioma-like), with tumours that were highly cellular, less invasive, and with a better overall prognosis. In tumours from group 4, amyloid deposition was characteristically absent or low. The spindle cell variant appeared only in tumours from group 3, which had high cellularity and a degree of invasion and prognosis intermediate between groups 1 and 2, but better than group 4. The grade of fibrosis correlated directly with the clinical outcome. CONCLUSION: Our results support the idea that a genotype-phenotype correlation does, indeed, exist in MTC. However, further studies are warranted to confirm these findings in a larger sample size.

Nicotine exposure during lactation causes disruption of hedonic eating behavior and alters dopaminergic system in adult female rats.

Tobacco smoke during gestation is associated with increased consumption of palatable foods by the offspring in humans and rats. Postpartum relapse is observed in lactating women who quit smoking during pregnancy, putting their children at risk of adverse health outcomes caused by secondhand smoke. Nicotine is transferred through milk and alters the dopaminergic reward system of adult male rats, reducing dopamine action in the nucleus accumbens (NAc) and hypothalamic arcuate nucleus. Here, we evaluated the long-term effects of nicotine-only exposure during lactation on eating behavior, anxiety, locomotion, dopaminergic system, hypothalamic leptin signaling and nicotinic receptor in the adult female rat progeny. Two days after birth (PN2), Wistar rat dams were separated into control and nicotine (Nic) groups for implantation of osmotic minipumps that released respectively saline or 6 mg/kg nicotine. Lactating dams were kept with 6 pups. After weaning (PN21; nicotine withdrawal), only the female offspring were studied. Euthanasia occurred at PN180. Nic females showed hyperphagia, preference for a high-sucrose diet, increased anxiety-like behavior, lower tyrosine hydroxylase (TH), lower dopamine transporter and higher dopamine receptor (Drd2) in NAc; lower Drd1 in prefrontal cortex and lower TH in dorsal striatum (DS). These animals showed changes that can explain their hyperphagia, such as: lower leptin signaling pathway (Leprb, pJAK2, pSTAT3) and Chrna7 expression in hypothalamus. Neonatal nicotine exposure affects the brain reward system of the female progeny differently from males, mainly decreasing dopamine production in NAc and DS. Therefore, Nic females are more susceptible to develop food addiction and obesity.

Patient and healthcare delays in critical and non-critical pulmonary tuberculosis incidence areas in Portugal: are there differences?

OBJECTIVES: To characterize patient, healthcare, and total delay in diagnosing pulmonary tuberculosis (PTB) in critical (higher PTB incidence) and non-critical (lower PTB incidence) areas and their determinants considering clinical and sociodemographic factors. STUDY DESIGN: Retrospective cohort study. METHODS: Data was retrieved from the Portuguese National Tuberculosis Surveillance System (SVIG-TB). Were included in the study all active PTB patients (n = 11,762) notified between 2008 and 2017. Spatial analysis was used to define critical and non-critical areas. Kaplan-Meier estimator, logrank test, and Cox regression were conducted, stratified by area. RESULTS: PTB cases in critical areas (n = 6594, 56.1%) presented longer patient median delay (41 vs 31days), shorter healthcare median delay (7 vs 10 days), and longer total median delay (63 vs 61days) t.han non-critical areas. Patient and total delay increased in both areas over time, while healthcare delay only increased in non-critical areas. Icn both areas, being from a high TB incidence country and alcohol abuse were associated with longer patient delays. Being female, older age, and oncologic diseases were associated with longer healthcare delays. Respiratory diseases were only associated with a longer healthcare delay in non-critical areas. Being female, older, and from a high TB incidence country were associated with a longer total delay in both areas. CONCLUSIONS: Patient delay was significantly longer in critical areas, and healthcare delay was significantly longer in non-critical areas. Several factors associated with longer delays have been identified, most of which are shared by critical and non-critical areas. Differences in patient and healthcare delay, for example, by sex, age, or country of birth, highlight the need for targeted public health interventions to help reduce these differences.

First report of root-knot nematode, Meloidogyne incognita, infecting hops, Humulus lupulus, in São Paulo, Brazil.

In 2019, during a nematologic survey in Jaboticabal, Brazil, root-knot nematode Meloidogyne incognita parasitizing hops (Humulus lupulus) was identified with based on morphological characters of adults, esterase phenotypes (n = 16), and molecular analysis. Modified Koch's postulates was carried out and after 90 days, the average total population recovered had different stages of development, with a reproductive factor (RF) of 4.81. This is the first report of H. lupulus as a host of M. incognita in the state of São Paulo and in Brazil.

Untangling Neolithic and Bronze Age mitochondrial lineages in South Asia.

Two key moments shaped the extant South Asian gene pool within the last 10 thousand years (ka): the Neolithic period, with the advent of agriculture and the rise of the Harappan/Indus Valley Civilisation; and Late Bronze Age events that witnessed the abrupt fall of the Harappan Civilisation and the arrival of Indo-European speakers. This study focuses on the phylogeographic patterns of mitochondrial haplogroups H2 and H13 in the Indian Subcontinent and incorporates evidence from recently released ancient genomes from Central and South Asia. It found signals of Neolithic arrivals from Iran and later movements in the Bronze Age from Central Asia that derived ultimately from the Steppe. This study shows how a detailed mtDNA phylogeographic approach, combining both modern and ancient variation, can provide evidence of population movements, even in a scenario of strong male bias such as in the case of the Bronze Age Steppe dispersals.

Individuals with filaggrin-related eczema and asthma have increased long-term medication and hospital admission costs.

BACKGROUND: Eczema and asthma are chronic diseases with onset usually before the age of 5 years. More than 50% of individuals with eczema will develop asthma and/or other allergic diseases. Several loss-of-function mutations in filaggrin (FLG) have been identified in patients with eczema. However, the association of FLG with healthcare use is unknown. OBJECTIVES: To determine whether FLG mutations are associated with increased prescribing for eczema and asthma and whether increased prescribing is associated with increased healthcare costs. METHODS: A secondary analysis of BREATHE, a cross-sectional study of gene-environment associations with asthma severity, was undertaken. BREATHE data was collected for 1100 participants with asthma, in Tayside and Fife, Scotland during the period 2003-2005. Through collaboration with the Health Informatics Centre in Dundee, BREATHE was linked to accident and emergency, community prescribing and Scottish morbidity records. The data linkage allowed longitudinal exploration of associations between genetic variation and prescribing. RESULTS: An association was found between FLG mutations and increased prescribing for mild and moderate eczema, asthma-reliever medicine and asthma exacerbations. A strong association was found between FLG mutations and prescribing of emollients [incidence rate ratio (IRR) 2·19, 95% confidence interval (CI) 1·36-3·52], treatment for severe eczema (IRR 2·18, 95% CI 1·22-3·91) and a combination of a long-acting ß2 -agonist and corticosteroids (IRR 3·29, 95% CI 1·68-6·43). CONCLUSIONS: The presence of FLG mutations in this cohort is associated with increased prescribing for eczema and asthma. Randomized controlled trials are required to determine if these individuals could benefit from management strategies to reduce morbidity and treatment costs.

Periodontal therapy for patients before and after radiotherapy: A review of the literature and topics of interest for clinicians.

BACKGROUND: To review and discuss important topics regarding periodontal treatment pre- and post-radiotherapy for head and neck cancer in human patients; to discuss the references for adequate techniques, the appropriate moment for tooth extractions and periodontal management; and to discuss the prevention of osteoradionecrosis. MATERIAL AND METHODS: Thirty-nine studies including original studies, randomized clinical trials (RCTs) and reviews were searched in online databases MEDLINE (PubMed) and the Cochrane library. No year of publication restriction was applied. RESULTS: Language was restricted to English, and the following Medical Subject Heading terms were used: radiotherapy, radiation therapy and periodontal treatment. Studies regarding periodontal treatment and tooth extraction that involved clinical management of irradiated patients were selected. CONCLUSIONS: The treatment of periodontal diseases before radiotherapy is mainly required to avoid future dental extraction and to reduce the development of osteoradionecrosis. Periodontal treatment in irradiated patients mostly includes scaling and root planing, extraction of condemned teeth and topical and systemic antimicrobial therapy. Tooth removal should be planned at least 14 days before the first day of radiation treatment. Particular care and mouthwashes should be taken during and after radiation. CLINICAL SIGNIFICANCE: The management of irradiated patients represents a challenge for health professionals, including dentists. It is important to establish recommendations for clinicians concerning dental and periodontal management in irradiated patients before, during and after treatment.

Effect of different storage media on root dentine composition and viability of fibroblasts evaluated by several assay methods.

AIM: To perform multiparametric analysis of the effects of soya milk (SM), whole milk (WM) and Hank's balanced salt solution (HBSS) on the viability of fibroblasts (HGF). The study also aimed to evaluate the influence of these solutions on bovine root dentine according to OH- and PO43- on the surface. METHODOLOGY: The HGF cytotoxicity was determined according to XTT, NR and SRB assays at 1, 3 and 6 h. Root dentine fragments were assessed by Fourier infrared (FTIR) spectrophotometer before and after immersion in the solutions for the same periods. The positive control group included cells and tooth fragments maintained in Dulbecco's modified Eagle's medium (DMEM), and the negative control included tooth fragments that were kept dry. Data were analysed using anova and Tukey's test. RESULTS: No significant difference was found in cell viability evaluated by XTT (P > 0.05). Using the NR assay, WM and HBSS had significantly lower cell viability compared to the positive control group at 6 h (P < 0.05). SM had similar cell viability to the positive control group at all periods evaluated when assessed using all three tests (P > 0.05). A significant difference was found in values of OH- for the negative control group at 1 h (P = 0.002). CONCLUSIONS: Soya milk promoted better cell viability, whereas on dentine composition, the solutions behaved similarly. The association of different assay methods is promising for improving cell viability analysis. The 1-h time-point is a crucial factor in the prognosis of dental replantation because the teeth remain more hydrated and help maintain cell viability.

Powdered coconut water as a storage medium to preserve the viability of periodontal ligament cells: a laboratory study.

AIM: To investigate the ability of newly developed powdered coconut water formulas (ACP) with different osmolarities to maintain the viability of periodontal ligament (PDL) cells over time compared with other solutions. METHODOLOGY: Dogs teeth were extracted and stored for two periods, 3 h or 24 h, in the following media: long-shelf life CW (CW), pH-adjusted long-shelf life CW (pH-CW) and powdered CW that was pH and osmolality adjusted (ACP-404-I, 250 mOsm kg-1 H2 O; pH 7.0; ACP-404-II, 372 mOsm kg-1 H2 O; pH 7.0; ACP-404-III, 300 mOsm kg-1 H2 O; pH 7.4). The positive control group (Pc) corresponded to immediate measurement after tooth extraction, and two negative controls (Nc) corresponded to 3 h and 24 h of dry time. PDL cells were extracted, and cell viability analysed by Trypan blue exclusion. Data were analysed statistically using two-way anova followed by the Tukey test and one-way anova followed by the Dunnett test (P < 0.05). RESULTS: At 3 h and 24 h, ACP-404-I had a performance similar to those of ACP-404-II and pH-CW, with significantly higher (P = 0.004) percentages of viable cells than ACP-404-III and CW. The positive control group had a significantly higher (P = 0.002) percentage of viable cells than the negative control groups, CW and ACP-404-III, irrespective of the period evaluated. CONCLUSION: Powdered coconut water formulas, ACP-404-I and ACP-404-II, preserved viability for up to 24 h.

Predictors of musculoskeletal pain in the upper extremities of individuals with spinal cord injury.

INTRODUCTION: Increased demands on the upper extremities (UE) have been associated with a higher occurrence of musculoskeletal pain in individuals with spinal cord injury (SCI). STUDY DESIGN: This is a cross-sectional retrospective study. OBJECTIVE: The aim of this study was to characterize SCI subjects with musculoskeletal pain in the UE and to determine which variables could predict musculoskeletal pain in these individuals. SETTING: The study was conducted in SARAH Network of Rehabilitation Hospitals, Brasília, Brazil. METHODS: Five hundred sixty-four electronic medical records were investigated through a retrospective, exploratory and descriptive analysis to identify individuals with UE pain. A logistic regression model was applied to estimate (odds ratios) whether gender, age, the level of injury, severity of injury, time of injury, body mass index, type of mobility and locomotion aid could predict the occurrence of musculoskeletal pain. RESULTS: The prevalence of musculoskeletal pain in the UE was 27.7%. The odds of having musculoskeletal pain were two times higher among woman and tetraplegic patients; those over 41 years of age had twice the frequency of pain than did those <24.7 years; <1 year of injury was a predictor of musculoskeletal pain, compared with the other quartiles (1.1-2.8, 2.9-6.8 and 6.9+ years of injury). There were no differences between the wheelchair and ambulatory individuals. CONCLUSION: Female individuals, those with tetraplegia, aged >40 years and <1 year of injury showed an increased risk of musculoskeletal pain.

Acute Hypotensive Response to Continuous and Accumulated Isocaloric Aerobic Bouts.

Evidence indicates that chronic reductions in blood pressure (BP) due to aerobic exercise depend on the ability to induce post-exercise hypotension (PEH) after each training bout. The purpose of this study was to investigate PEH after isocaloric bouts of continuous and accumulated running. 10 healthy pre-hypertensive men (aged 27.6±3.5 years) performed the following bouts of exercise: a) A continuous bout (CONT) expending a total of 400 kcal; and b) An accumulated bout split into 2×200 kcal (INTER1 and INTER2) to total 400 kcal at 75% of oxygen uptake reserve. BP, mean arterial pressure (MAP) and heart rate variability were monitored 10 min before and 60 min after control and all exercise conditions. The decrease in MAP over time after continuous (400 kcal) and accumulated (2×200 kcal) bouts of exercise was more pronounced than during control (mean diff between 1.6 and 5.4 mmHg, P≤0.01), although the magnitude of change was similar between continuous and accumulated bouts (mean diff=0.1 mmHg, P=0.79). Concomitant to the PEH, sympathovagal balance was inversely related to changes in MAP after isocaloric bouts performed continuously and cumulatively (r=- 0.72 and-0.85, P=0.019 and 0.002, respectively). In conclusion, BP decreased to similar levels after continuous and accumulated acute aerobic exercise matched for total energy expenditure. Our findings also indicate that the recovery pattern of cardiac autonomic activity may have an important role in eliciting PEH.

Assembling and auditing a comprehensive DNA barcode reference library for European marine fishes.

A large-scale comprehensive reference library of DNA barcodes for European marine fishes was assembled, allowing the evaluation of taxonomic uncertainties and species genetic diversity that were otherwise hidden in geographically restricted studies. A total of 4118 DNA barcodes were assigned to 358 species generating 366 Barcode Index Numbers (BIN). Initial examination revealed as much as 141 BIN discordances (more than one species in each BIN). After implementing an auditing and five-grade (A-E) annotation protocol, the number of discordant species BINs was reduced to 44 (13% grade E), while concordant species BINs amounted to 271 (78% grades A and B) and 14 other had insufficient data (grade D). Fifteen species displayed comparatively high intraspecific divergences ranging from 2·6 to 18·5% (grade C), which is biologically paramount information to be considered in fish species monitoring and stock assessment. On balance, this compilation contributed to the detection of 59 European fish species probably in need of taxonomic clarification or re-evaluation. The generalized implementation of an auditing and annotation protocol for reference libraries of DNA barcodes is recommended.

[Achalasia: which treatment to choose in 2015?]. / Achalasie: queulle thérapie choisir en 2015 ?

Achalasia is a rare disorder, whose diagnostic Gold standard is high-resolution cesophageal manometry. The proposed treatment must take into account the patient's health condition and the type of achalasia determined by HRM. Heller's laparoscopic myotomy and pneumatic dilation are the first line treatments for most of the patients, whereas Botulinum toxin injections and pharmacologic therapy are only indicated for patients with a high surgical risk who cannot undergo first line treatments. Peroral endoscopic myotomy (POEM) is a recent and promising endoscopic technique reserved for expert endoscopy centers, whose exact role is still to be determined by randomized prospective studies. Oesophagectomy has only a marginal role in rare patients with extremely advanced achalasia or at risk of neoplastic degeneration.

Effect of leptin on in vivo goat embryo production.

The aim of this study was to evaluate the effect of leptin administration during superovulation on in vivo goat embryo production. Ten mature does were superovulated with 133 mg follicle-stimulating hormone (FSH) i.m. in six descending doses at 12-h intervals. The goats received 4.8 µg/kg human recombinant leptin s.c. (leptin group, n = 5) or phosphate-buffered saline (PBS) (control group, n = 5) with the first and second FSH doses. The does were mated and subjected to embryo collection by transcervical technique 6 days later. The total number of cells per embryo and the number of cells with fragmented DNA were assessed in selected blastocysts by combining Hoechst 33342 and terminal dUTP nick-end labelling (TUNEL) staining. Plasma concentrations of oestradiol (E2 ) and progesterone (P4 ) were determined by electrochemiluminescence from the day of FSH treatment, on the day of superovulatory oestrus and on the day before embryo collection. Compared with the control group, the does that received leptin had a higher number of transferable embryos (p < 0.005), fewer embryos classified as degenerated (p < 0.001) and fewer TUNEL-positive cells/blastocyst (p < 0.001). The number of transferable embryos was positively correlated with E2 concentrations on day of oestrus (r = 0.562; p < 0.01) and P4 concentrations on the day of embryo collection (r = 0.912; p < 0.001). We concluded that in vivo leptin administration during FSH treatment improved embryo quality and affected ovarian steroidogenesis in superovulated goats.

Effect of root morphology on biomechanical behaviour of premolars associated with abfraction lesions and different loading types.

The aim of this study was to investigate the biomechanical behaviour of maxillary premolar teeth regarding root morphology and abfraction depth, submitted to axial and oblique occlusal load. The investigation was conducted using 3D finite element analysis and strain gauge test. Sound maxillary premolar single and double root were selected for 3D model generation. The teeth were scanned for external morphology data acquisition. The 3D geometry was stored in *.STL and exported to Bio-CAD software (Rhinoceros-3D) to model generation. Mesh generation, mechanical properties and boundary conditions were performed in finite element software (Femap, Noran Engineering, USA). Twelve models were generated: sound tooth, 1.25 and 2.5 mm abfraction teeth. 100N compressive static load was applied: axially and 45° angle to the long axis on the palatine surface of the buccal cusp. Two strain gauges were bonded on the teeth mounted in a mechanical testing machine. Von Mises criterion showed that the double-root teeth associated with 2.5 mm abfraction and oblique loading presented higher stress values. Axial loading associated with single-root teeth propitiated the lowest stress rates. Double root sound 1.25 and 2.5 mm abfraction teeth associated with oblique loading showed the highest strain values (µS): 692.6, 1043.31 and 1236.14, respectively. Single root sound 1.25 and 2.5 mm abfraction teeth associated with oblique loading showed 467.10, 401.51 and 420.98 strain values, respectively. Axial loading showed lower strain rates, ranging from 136.12 to 366.91. The association of deep lesions, oblique loading and double-root tooth promoted higher stress and strain concentration.