Analysis of viral diversity in dogs with acute gastroenteritis from Brazilian Amazon.

Viral gastroenteritis is commonly reported in dogs and involves a great diversity of enteric viruses. In this research, viral diversity was investigated in dogs with diarrhea in Northern Brazil using shotgun metagenomics. Furthermore, the presence of norovirus (NoV) was investigated in 282 stool/rectal swabs of young/adult dogs with or without diarrhea from two public kennels, based on one-step reverse transcription polymerase chain reaction (RT-PCR) for genogroup VI and VII (GVI and GVII) and real-time RT-PCR for GI, GII, and GIV. Thirty-one viral families were identified, including bacteriophages. Phylogenetic analyses showed twelve complete or nearly complete genomes belonging to the species of Protoparvovirus carnivoran1, Mamastrovirus 5, Aichivirus A2, Alphacoronavirus 1, and Chipapillomavirus 1. This is the first description of the intestinal virome of dogs in Northern Brazil and the first detection of canine norovirus GVII in the country. These results are important for helping to understand the viral groups that circulate in the canine population.

Assessing Left Ventricular Pathology in Patients with Ebstein Anomaly Using Cardiovascular Magnetic Resonance: Looking Past the Right Heart.

Ebstein Anomaly (EA) is a malformation of the right heart, but there is data to suggest that the left ventricle (LV) can suffer from intrinsic structural and functional abnormalities which affect surgical outcomes. The LV in patients with EA is hypertrabeculated with abnormalities in LV function and strain. In this retrospective single-center study, patients with EA who underwent pre-operative cardiac MRI (CMR) between the periods of 2014-2024 were included along with a group of healthy-age-matched controls. Left ventricular and right ventricular volume, function and strain analyses were performed on standard SSFP imaging. LV noncompacted: compacted (NC/C) ratio and the displacement index of the tricuspid valve were measured. Forty-seven EA patients were included with mean age of 21.0 ± 17.6 years. Seventeen EA patients (36%) had mild pre-operative LV dysfunction on CMR and 1 (2.1%) had moderate LV dysfunction. Out of these 18 patients with LV dysfunction, only 2 were detected to have dysfunction on Echocardiogram. The global circumferential and longitudinal strain were significantly lower in the reduced LVEF group compared to those with preserved LVEF (- 14.8% vs. - 17%, p = 0.02 and - 11.9% vs. - 15.0%; p = 0.05; respectively) on CMR. A single EA patient met criteria for LVNC with a maximal NC/C ratio > 2.3. There was no statistically significant difference in NC/C ratio in the EA population (1.4 ± 0.6) vs. controls (1.1 ± 0.2), p = 0.17. There was an inverse correlation of LV ejection fraction with right ventricular end-diastolic volume and displacement index. All patients underwent the Da Silva Cone procedure at our center. Patients with preoperative LV dysfunction had longer duration of epinephrine use in the immediate postoperative period (33.7 ± 21.4 vs 10.2 ± 25.6 h, p = 0.02) and longer length of hospital stay (6.3 ± 3.2 vs 4.4 ± 1.2 days, p = 0.01). This is the largest study to date to evaluate preoperative LV structure and function in EA patients by CMR. In this cohort of 47 patients, preoperative LV dysfunction is fairly common and CMR has high sensitivity in detecting LV dysfunction as compared to Echo. True LV non-compaction was rare in this cohort. The presence of LV dysfunction is relevant to perioperative management and further study with larger cohorts and longer follow up are necessary.

Evaluation of soluble co-inhibitors and co-stimulators levels of the immune response in gastric cancer.

BACKGROUND: Co-inhibitor and co-stimulator mediators trigger actions that result in immunological homeostasis and are being evaluated as potential therapeutic targets in gastric cancer (GC). OBJECTIVE: To evaluate the soluble levels of sPD-1, sPD-L1, sPD-L2, sTIM-3, sGal9, sGITR, and sGITRL in GC patients. METHODS: The cross-sectional study was carried out at the Hospital de Cancer de Pernambuco, Brazil between 2017 and 2018. A total of 74 GC patients and 30 healthy controls were included. RESULTS: Low levels of sPD1 (p = 0.0179), sPDL2 (p = 0.0003), and sGal9 (p < 0.0001), and higher levels of sPDL1 (p = 0.004), sTIM-3 (p = 0.0072), sGITR (p = 0.0179), and sGITRL (p = 0.0055) compared to the control group. High sPD-1, sTIM-3, and sGal9 levels in stage IV compared I/II and III (p < 0.05). High sPDL1, sGal9, and sGITRL levels in esophagogastric junction compared to body and Pylorus/Antrum groups (p < 0.05). No significant differences were observed in sPD1, sPDL1, sPDL2, sTIM3, sGal9, sGITR, and sGITRL levels between the intestinal, diffuse, and mixed GC groups. Low sGITR levels in GC patients who died within the first 24 months compared to the who survived (p = 0.0332). CONCLUSIONS: There is an association of sPD1, sTIM-3, and sGal9 with disease progression and sGITR with death, these mediators may be potential prognostic biomarkers in GC.

Soluble levels of 4-1BB (CD137) and OX40 (CD134) are associated with cancer progression in gastric adenocarcinoma.

BACKGROUND AND OBJECTIVES: Previous studies have demonstrated that soluble forms of T-cell costimulatory molecules 4-1BB (s4-1BB) and OX40 (sOX40) interact with immune cells and may constitute a mechanism of immune evasion by tumors in various cancers. The role of the soluble forms of 4-1BB and OX40 in GC remains unclear. We aimed to examine the association between serum levels of s4-1BB and sOX40 and tumor progression in patients with GC. METHODS: Between 2017 and 2018, a cross-sectional study was performed with serum samples of 83 GC patients and 20 healthy controls. RESULTS: Patients with stage IV metastatic gastric cancer had significantly higher levels of soluble OX40 in comparison with stage III patients with lymph nodes metastasis (p = 0.0003) and stages I and II patients (p = 0.005), whereas the opposite was found for soluble 4-1BB levels, with lower levels being found in advanced stage III (p = 0.003) compared with initial stages I/II. CONCLUSIONS: The sOX40 and s4-1BB-mediated T cell interactions may be involved in antitumor immune responses in GC, possibly favoring tumor escape and progression. Serum levels of sOX40 and s4-1BB are associated with staging in GC and may constitute biomarkers for prognosis, as well as potential targets for immunotherapy.

The American Association for Thoracic Surgery (AATS) 2024 expert consensus document: Management of neonates and infants with Ebstein anomaly.

OBJECTIVES: Symptomatic neonates and infants with Ebstein anomaly (EA) require complex management. A group of experts was commissioned by the American Association for Thoracic Surgery to provide a framework on this topic focusing on risk stratification and management. METHODS: The EA Clinical Congenital Practice Standards Committee is a multinational and multidisciplinary group of surgeons and cardiologists with expertise in EA. A citation search in PubMed, Embase, Scopus, and Web of Science was performed using key words related to EA. The search was restricted to the English language and the year 2000 or later and yielded 455 results, of which 71 were related to neonates and infants. Expert consensus statements with class of recommendation and level of evidence were developed using a modified Delphi method, requiring 80% of members votes with at least 75% agreement on each statement. RESULTS: When evaluating fetuses with EA, those with severe cardiomegaly, retrograde or bidirectional shunt at the ductal level, pulmonary valve atresia, circular shunt, left ventricular dysfunction, or fetal hydrops should be considered high risk for intrauterine demise and postnatal morbidity and mortality. Neonates with EA and severe cardiomegaly, prematurity (<32 weeks), intrauterine growth restriction, pulmonary valve atresia, circular shunt, left ventricular dysfunction, or cardiogenic shock should be considered high risk for morbidity and mortality. Hemodynamically unstable neonates with a circular shunt should have emergent interruption of the circular shunt. Neonates in refractory cardiogenic shock may be palliated with the Starnes procedure. Children may be assessed for later biventricular repair after the Starnes procedure. Neonates without high-risk features of EA may be monitored for spontaneous closure of the patent ductus arteriosus (PDA). Hemodynamically stable neonates with significant pulmonary regurgitation at risk for circular shunt with normal right ventricular systolic pressure should have an attempt at medical closure of the PDA. A medical trial of PDA closure in neonates with functional pulmonary atresia and normal right ventricular systolic pressure (>20-25 mm Hg) should be performed. Neonates who are hemodynamically stable without pulmonary regurgitation but inadequate antegrade pulmonary blood flow may be considered for a PDA stent or systemic to pulmonary artery shunt. CONCLUSIONS: Risk stratification is essential in neonates and infants with EA. Palliative comfort care may be reasonable in neonates with associated risk factors that may include prematurity, genetic syndromes, other major medical comorbidities, ventricular dysfunction, or sepsis. Neonates who are unstable with a circular shunt should have emergent interruption of the circular shunt. Neonates who are unstable are most commonly palliated with the Starnes procedure. Neonates who are stable should undergo ductal closure. Neonates who are stable with inadequate pulmonary flow may have ductal stenting or a systemic-to-pulmonary artery shunt. Subsequent procedures after Starnes palliation include either single-ventricle palliation or biventricular repair strategies.

Environmental health of water bodies from a Brazilian Amazon Metropolis based on a conventional and metagenomic approach.

AIMS: The present study aimed to use a conventional and metagenomic approach to investigate the microbiological diversity of water bodies in a network of drainage channels and rivers located in the central area of the city of Belém, northern Brazil, which is considered one of the largest cities in the Brazilian Amazon. METHODS AND RESULTS: In eight of the analyzed points, both bacterial and viral microbiological indicators of environmental contamination-physical-chemical and metals-were assessed. The bacterial resistance genes, drug resistance mechanisms, and viral viability in the environment were also assessed. A total of 473 families of bacteria and 83 families of viruses were identified. Based on the analysis of metals, the levels of three metals (Cd, Fe, and Mn) were found to be above the recommended acceptable level by local legislation. The levels of the following three physicochemical parameters were also higher than recommended: biochemical oxygen demand, dissolved oxygen, and turbidity. Sixty-three bacterial resistance genes that conferred resistance to 13 different classes of antimicrobials were identified. Further, five mechanisms of antimicrobial resistance were identified and viral viability in the environment was confirmed. CONCLUSIONS: Intense human actions combined with a lack of public policies and poor environmental education of the population cause environmental degradation, especially in water bodies. Thus, urgent interventions are warranted to restore the quality of this precious and scarce asset worldwide.

Optimizing Surgical Selection for Transposition With Left Ventricular Outflow Tract Obstruction.

BACKGROUND: Studies that have assessed the Rastelli and Nikaidoh operations for transposition of the great arteries (TGA) with obstructed left ventricular outflow tract obstruction (LVOTO) have not fully evaluated the anatomic drivers that may contribute to surgical selection. We present our procedural selection process for optimizing outcomes of complex TGA in the modern era. METHODS: This is a single-center, retrospective study that included pediatric patients who underwent either a Nikaidoh or Rastelli operation for the treatment of TGA-LVOTO, congenitally corrected TGA-LVOTO, or double-outlet right ventricle TGA type-LVOTO from June 2004 to June 2021. RESULTS: There were 34 patients stratified by Nikaidoh (n = 16) or Rastelli (n = 18) operation. The incidence of all postoperative complications and mortality was low, and the incidence of complications between the groups was similar. Patients were more likely to have undergone a Nikaidoh than a Rastelli if they had a pulmonary annulus >5 mm (87.5% vs 11.1%), anteriorly/posteriorly oriented great vessels (88% vs 8%), remote (80% vs 11%) or restrictive (75% vs 6%) ventricular septal defect, and right ventricular hypoplasia (50% vs 0%; all, P < .05). The resulting rates of reoperation were similar between the groups (44.0% vs 37.5%; P = .24) and largely composed of conduit replacements in the Rastelli patients and valvular repairs or replacements in the Nikaidoh group. Rates of catheter-based interventions were also similar. CONCLUSIONS: These findings suggest that for the optimal treatment of conotruncal anomalies with discordant ventriculoarterial connections, procedural selection should be based on pathoanatomic criteria that can ensure patients undergo the operation most suited to their anatomy.

Using DaSilva Cone Operation to Establish 1.5 or 2 Ventricle Circulation After Initial Single Ventricle Palliation with Starnes Procedure.

Ebstein anomaly (EA) is a congenital dysplasia of the tricuspid valve resulting in reduced right ventricular (RV) volume and tricuspid regurgitation. Severe EA in the neonatal period is associated with high mortality. The Starnes procedure (fenestrated RV exclusion) is reserved for EA patients with cardiogenic shock and has previously committed patients to single ventricle (SV) palliation. In this report, we present the results of a strategy to redirect patients utilizing the Da Silva Cone operation to achieve a 2 or 1.5 ventricle circulation. Single-center retrospective study including all consecutive cases of Da Silva Cone operation after Starnes procedure. Between 2019 and 2023, six conversions from Starnes procedure to Cone reconstruction were performed. All were critically ill before their Starnes procedure; four on extracorporeal membrane oxygenation. Two patients were successfully rerouted to a two-ventricle repair; the remainder to 1.5 ventricle circulation. RV pressure estimates showed no correlation with success. Post-Cone intensive care and hospital stays were brief, median 5 and 6 days, respectively. All are between 2.5 and 6 years old, without indications for SV palliation. There were no deaths, with follow up ranging 1 month-4 years. No repeat interventions were performed on the tricuspid valves. One subject had a surgical pulmonary valve replacement. Tricuspid regurgitation was mild in all. The Da Silva Cone operation offers successful redirection of EA patients from a SV pathway to a 1.5 or 2 ventricle pathway after Starnes procedure. The approach is feasible and durable in midterm follow-up. The decision to initially proceed with Starnes need not be an irrevocable decision to continue down a SV palliation pathway.

Molecular analysis of canine circovirus in dogs from animal shelters in Belém, Pará, northern Brazil: first detection at the amazon region.

The canine circovirus (CanCV) is a single-stranded DNA virus that has become an important emerging virus associated with gastroenteritis in dogs worldwide. In the present study, the CanCV was detected by PCR in 15% (22/147) of dogs from animal shelters in Belém, between 2019 and 2020. We observed an association between the CanCV infection and the presence of diarrhea in animals younger than one year of age (p > 0.01). The Brazilian strains were grouped in Chinese genotypes, with 99.54 to 100% nucleotilde homology. The GMRF Bayesian Skyride used the molecular clock model, which was the best suited technique to plot the dataset. The most recent common ancestor (TMRCA) was estimated in 2017, with the evolution rate of 1.6 x 10-3 s/s/y. The viral family diversity was also investigated, with emphasis on the families of the enteric pathogenic viruses Parvoviridae, Picornaviridae and Astroviridae, which were detected in the CanCV positive pooled samples. This study highlights the importance of the CanCV as an emergent virus that causes diarrhea in Brazilian dogs. The results found herein contribute to the understanding of the role of CanCV in enteric diseases and in the evolutionary molecular characterization of the circulating genotypes. Furthermore, we increased the understanding of the fecal virome in dogs with diarrhea, providing data for the monitoring and prevention viral gastroenteric diseases in domestic animals.

O circovírus canino (CanCV) é um vírus de DNA de fita simples que se tornou um importante vírus emergente associado à gastroenterite em cães em todo o mundo. No presente estudo, o CanCV foi detectado por PCR em 15% (22/147) dos cães de abrigos de animais em Belém, entre 2019 e 2020. Observamos uma associação entre a infecção pelo CanCV e a presença de diarreia em animais menores de um ano de idade (p > 0,01). As linhagens brasileiras foram agrupadas em genótipos chineses, com 99,54 a 100% de homologia nucleotídica. O GMRF Bayesian Skyride foi o modelo de relógio molecular utilizado, sendo o método mais adequado para o conjunto de dados. O ancestral comum mais recente (TMRCA) foi estimado em 2017, com taxa de evolução de 1,6 x 10-3 s/s/ano. A diversidade de famílias virais também foi investigada, com destaque para as famílias dos vírus patogênicos entéricos Parvoviridae, Picornaviridae e Astroviridae, que foram detectadas nos pools de amostras positivas para CanCV. Este estudo destaca a importância do CanCV como um vírus emergente que causa diarreia em cães brasileiros. Os resultados aqui encontrados contribuem para a compreensão do papel do CanCV nas doenças entéricas e na caracterização molecular evolutiva dos genótipos circulantes. Além disso, aumentamos a compreensão do viroma fecal em cães com diarreia, fornecendo dados para o monitoramento e prevenção de doenças gastroentéricas virais em animais domésticos.

Circulation of adenovirus and other viruses in urban drainage channels: an environmental surveillance in Belém, Amazon region, Brazil.

Urban channels in amazon cities are very polluted, with garbage and sewage disposal in these aquatic environments, favoring the high dissemination of waterborne viruses such as human adenovirus (HAdV). The aim of this study was to perform the detection and molecular characterization of adenovirus in urban channels and in a wastewater treatment plant located in a metropolitan city in the Amazon. Additionally, metagenomic analyses were performed to assess viral diversity. Samples were concentrated by organic flocculation, analyzed by quantitative real time PCR (qPCR) and sequenced (Sanger e next generation sequencing). Cell culture was performed to verify the viability of HAdV particles. A total of 104 samples were collected, being the HAdV positivity of 76% (79/104). Among the positive samples, 29.1% (23/79) were characterized as HAdV-F40 (87%, 20/23), HAdV-F41 (8.7%, 2/23), and HAdV-B (4.3%, 1/23). Average precipitation rates ranged from 163 to 614 mm, while the pH ranged from 6.9 to 7.6. Eight positive samples were inoculated into A549 cells and in 4 of these, was observed changes in the structure of the cell monolayer, alteration in the structure of the cell monolayer was observed, but without amplification when analyzed by PCR. The metagenomic data demonstrated the presence of 14 viral families, being the most abundant: Myoviridae (41% of available reads), Siphoviridae (24.5%), Podoviridae (14.1%), and Autographiviridae (6.9%) with more than 85% of the total number of identified reads. This study reinforcing that continuous surveillance may contribute to monitoring viral diversity in aquatic environments and provide early warning of potential outbreaks.

Pan-Cancer Prevalence of Microsatellite Instability-High (MSI-H) Identified by Circulating Tumor DNA and Associated Real-World Clinical Outcomes.

PURPOSE: Immune checkpoint inhibitors are approved for advanced solid tumors with microsatellite instability-high (MSI-H). Although several technologies can assess MSI-H status, detection and outcomes with circulating tumor DNA (ctDNA)-detected MSI-H are lacking. As such, we examined pan-cancer MSI-H prevalence across 21 cancers and outcomes after ctDNA-detected MSI-H. METHODS: Patients with advanced cancer who had ctDNA testing (Guardant360) from October 1, 2018, to June 30, 2022, were retrospectively assessed for prevalence. GuardantINFORM, which includes anonymized genomic and structured payer claims data, was queried to assess outcomes. Patients who initiated new treatment within 90 days of MSI-H detection were sorted into immunotherapy included in treatment (IO) or no immunotherapy included (non-IO) groups. Real-world time to treatment discontinuation (rwTTD) and real-world time to next treatment (rwTTNT) were assessed in months as proxies of progression-free survival (PFS); real-world overall survival (rwOS) was assessed in months. Cox regression tests analyzed differences. Colorectal cancer, non-small-cell lung cancer (NSCLC), prostate cancer, gastroesophageal cancer, and uterine cancer (UC) were assessed independently; all other cancers were grouped. RESULTS: In total, 1.4% of 171,881 patients had MSI-H detected. Of 770 patients with outcomes available, rwTTD and rwTTNT were significantly longer for patients who received IO compared with non-IO for all cancers (P ≤ .05; hazard ratio [HR] range, 0.31-0.52 and 0.25-0.54, respectively) except NSCLC. rwOS had limited follow-up for all cohorts except UC (IO 39 v non-IO 23 months; HR, 0.18; P = .004); however, there was a consistent trend toward prolonged OS in IO-treated patients. CONCLUSION: These data support use of a well-validated ctDNA assay to detect MSI-H across solid tumors and suggest prolonged PFS in patients treated with IO-containing regimens after detection. Tumor-agnostic, ctDNA-based MSI testing may be reliable for rapid decision making.

Detection of Cutibacterium acnes in Tissue Samples from Clean Primary Shoulder Surgeries - Part II.

Objective Research and identification of Cutibacterium acnes ( C. acnes ) and other microorganisms in deep tissue samples collected in clean shoulder surgeries of patients who did not undergo any previous invasive joint procedure and who had no clinical history of infection. Methods We analyzed the results of cultures of intraoperative deep tissue samples from 84 patients submitted to primary clean shoulder surgery. Tubes containing culture medium were used for storage and transport of anaerobic agents, prolonged incubation time, and mass spectrometer for diagnosis of bacterial agents. Results Bacteria growth was evidenced in 34 patients (40.4%) of the 84 included in the study. Of these, 23 had growth of C. acnes in at least one sample of deep tissue collected, corresponding to 27.3% of the total patients. The second most common agent was Staphylococcus epidermidis , present in 7.2% of the total individuals included. We showed a higher relationship between sample positivity and males, a lower mean age, absence of diabetes mellitus, ASA I score, and antibiotic prophylaxis in anesthetic induction with cefuroxime. Conclusions A high percentage of isolates of different bacteria was found in shoulder tissue samples of patients undergoing clean and primary surgeries, who had no history of previous infection. Identification of C. acnes was high (27.6%), and Staphylococcus epidermidis was the second most frequent agent (7.2%).

Health-related patterns and chronic kidney disease in the Brazilian population: National Health Survey, 2019.

Objective: The aim of this study was to identify patterns related to health and their association with chronic kidney disease (CKD) in the Brazilian population. Methods: We used data from the National Health Survey (PNS), 2019. Participants were interviewed and answered questions related to socioeconomic and demographic information (gender, age, education, race/color), health conditions (presence of hypertension, diabetes mellitus, hyperlipidemia, cardiovascular disease, overweight and CKD) and lifestyle (smoking, alcohol consumption, physical activity and food consumption). To identify patterns, we used exploratory factor analysis. We performed logistic regression models to describe the association of CKD with each pattern in crude models and adjusted for gender, age group, education level and race/color. Results: A total of 90,846 individuals were evaluated. The prevalence of CKD was 1.49% (95% CI: 1.3-1.6). Three health-related patterns - metabolic factors, behavioral risk factors and behavioral protective factors - were identified by factor analysis. Metabolic factors were determined by the presence of hypertension, diabetes mellitus, hyperlipidemia and cardiovascular diseases. Behavioral risk factors were determined by smoking, alcohol consumption, regular consumption of soft drinks, sweets and artificial juices, and high salt consumption. The protective behavioral factors were established by the practice of physical activity and regular consumption of vegetables and fruits. Participants of the highest tertile for metabolic factors were more likely to have CKD in the adjusted model (OR = 3.61, 95% CI: 2.69-4.85), when compared to those of the lower tertile. Conclusion: The pattern referring to metabolic factors was associated with a higher chance of presenting CKD.

Allograft-enhanced latissimus dorsi transfer is better than the conventional technique for irreparable posterosuperior rotator cuff tears. A retrospective matched cohort.

PURPOSE: Latissimus dorsi tendon (LDT) transfer (LDTT) to the greater tuberosity to treat irreparable posterosuperior rotator cuff tears (RCTs) in young active patients has been shown to have up to 36% of clinical failures, most of them happening because of either deltoid origin disruption or post-operative transfer rupture from the greater tuberosity. In an attempt to simultaneously prevent both complications, a modified technique includes the following adaptations to the original technique: reinforcement and augmentation of the LDT with a tendinous allograft, enabling the use of a single deltopectoral approach. The aim of this study is to compare mid-term outcomes of the traditional LDTT technique with this modified transfer. METHODS: Retrospective cohort study comparing two groups who underwent either the traditional (group 1; n = 19) or the modified technique (group 2; n = 27). Group homogenization was assured by statistical comparison of 24 baseline independent variables. The outcome variables were the gains to active shoulder range of motions (ROM) and UCLA scores (and all its subscores, independently), at a minimum follow-up of two years. A p value < .05 was considered to be statistically significant. RESULTS: At a mean follow-up of 25 months, both groups have shown improvements to most variables. However, group two (modified technique) achieved greater improvements to UCLA score (p = .009), active external rotation (p = .006) and internal rotation (p = .008). CONCLUSION: At mid-term follow-up, improvements to outcomes of the modified (single approach, allograft-enhanced) latissimus dorsi transfer were greater than those of the original technique.

Nearly Complete Genome Sequences of Two Canine Mamastrovirus 5 Strains from Latin America.

We report the nearly complete genome sequences of CAstV-PK01 and CAstV-PK03, two canine astrovirus strains belonging to the species Mamastrovirus 5, which were detected in fecal swab samples collected from puppies with diarrhea from two different kennels in the Brazilian Amazon.

Crown Material and Occlusal Thickness Affect the Load Stress Dissipation on 3D Molar Crowns: Finite Element Analysis

PURPOSE: To compare the mechanical behavior (stress load dissipation and/or concentration) of posterior crowns made from Lava Ultimate (LU; 3M ESPE) and IPS e.max CAD (LD; Ivoclar Vivadent) using finite element analysis (FEA). MATERIALS AND METHODS: A 3D model of a mandibular first molar was prepared by reducing the occlusal surface by 1 or 2 mm (according to group), the axial walls by 1.5 mm, and using a 0.8-mm-deep shoulder margin as a finish line. A convergence of 6 degrees between opposing walls was set. Subsequently, four 3D crown models were created according to two test groups with two different occlusal thicknesses: (1) LD with 1.0 mm (LD1); (2) LD with 2.0 mm (LD2); (3) LU with 1.0 mm (LU1); and (4) LU with 2.0 mm (LU2). FEA models were constructed using the software Femap (Siemens). A load of 200 N was applied in the axial and oblique (20 degrees) directions for each group, and stress dissipation was viewed using the NEi Nastran software. RESULTS: FEA results demonstrated that the LU crowns dissipated the occlusal load to the tooth structure, whereas the LD material concentrated the load inside the crowns. For the LU material, the lower the occlusal thickness, the higher the stress concentration inside the crown became, and the 2.0-mm occlusal thickness transferred lower stress to the tooth structure. The oblique, rather than the vertical, load caused an increase in the maximum stress concentration at the shoulder margin and axial walls. CONCLUSION: The higher the Young's Modulus mismatch between the crown material and substrate, the higher the load stress concentration inside the material became. The 2-mm occlusal thickness acted by decreasing the load stress to the tooth substrate. Finally, the axial load delivered more favorable stress transmission to the tooth substrate. The crown material and the occlusal thickness appear to be two factors that affect the mechanical behavior of stress dissipation to the tooth structure.

Congenital Heart Surgery Training Experiences and Perceptions Among Cardiothoracic Surgery Residents.

Interest and core training in congenital heart surgery (CHS) has not been characterized among current cardiothoracic surgical trainees. This study aimed to evaluate perceptions, interest, exposure, and experience among current trainees. A 22 question survey was distributed to all cardiothoracic surgical trainees in ACGME-accredited thoracic surgery residencies. Questions included demographics, exposure to CHS during, perceptions of, participation in and quality assessment of CHS training. There were 106 responses (20.1% response rate) of which 31 (29.0%) were female and 87 (81.3%) were cardiothoracic track. While 69 (64.5%) reported having an interest in CHS at some point during training, only 24 (22.4%) were actively pursuing CHS. All but 7 (6.5%) residents reported having easy access to congenital mentorship, with 35 (32.7%) actively participating in CHS research. Three months was the median duration of congenital rotations. Residents reported less operative participation on CHS compared to adult cardiac surgery. Several residents noted the need for earlier exposure and increased technical/operative experience as areas in need of improvement. The most cited primary influences to pursue CHS included: mentorship, breadth of pathology, and technical nature of the specialty. Lack of consistent job availability and length of additional training were reported as negative influences. Cardiothoracic residents report adequate exposure to obtain case requirements and knowledge for board examinations in CHS but highly variable operative involvement. Mentorship and early exposure remain important for those interested in CHS, while additional training time and limited job availability remain hurdles to CHS.