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Objective:To investigate the risk factors for recurrence of benign vocal cord lesions after microsurgery.Methods:The clinical data of 2 214 patients with benign vocal cord lesions who underwent laryngeal microsurgery at the Department of Otolaryngology-Head and Neck Surgery, Affiliated Hospital of Yangzhou University from April 2013 to April 2022 were collected. The data, including sex, age, drinking history, smoking history, unilateral and bilateral lesions, and diagnosis, were recorded. These patients were divided into six groups according to admission diagnosis: polyps, Reinke's edema, leukoplakia, granulomas, cysts, and other benign lesions. All patients were followed up for 0-115 months, with a median follow-up time of 55 months. The Kaplan-Meier curve was used to determine whether there was any difference in the recurrence rate of benign vocal cord lesions among groups after surgical treatment. The Cox regression model was used to analyze the risk factors for the recurrence of benign vocal cord lesions after surgical treatment.Results:Out of the 2 214 patients, there were 1 953 cases of polyps (88.21%), 41 cases of granulomas (1.85%), 67 cases of cysts (3.03%), 87 cases of leukoplakia (3.93%), 34 cases of Reinke's edema (1.54%), and 32 cases of other benign lesions (1.45%). The recurrence rate for benign vocal cord lesions was 4.86% (95/1 953) in the polyp group, 31.70% (13/41) in the granuloma group, 14.94% (13/87) in the leukoplakia group, 2.98% (2/67) in the cysts group, 8.82% (3/34) in the Reinke's edema group, and 9.37% (3/32) in the other benign lesions group. Univariate analysis showed that bilateral lesions (95% CI 6.899-17.289, P < 0.001), smoking history (95% CI 1.282-2.564, P = 0.001), and alcohol consumption (95% CI 1.173-2.346, P = 0.001) were significantly associated with the recurrence of benign vocal cord lesions. The recurrence rate for benign vocal cord lesions in the leukoplakia group (95% CI 1.375-27.011, P = 0.017) and granuloma group (95% CI 3.053-60.980, P = 0.001) was significantly higher than that in the cysts group. Multivariate analysis of the risk factors for postoperative recurrence of benign vocal cord lesions showed that patients who had bilateral lesions (95% CI 6.680-16.900, P < 0.001) and a history of smoking (95% CI 1.572-16.157, P = 0.007) had a higher risk of recurrence of benign vocal cord lesions compared with those without bilateral lesions and a history of smoking. Granulomas were found to be significantly associated with postoperative recurrence of benign vocal cord lesions (95% CI 4.691-97.667, P < 0.05). Conclusion:Bilateral lesions and smoking are independent risk factors for the recurrence of benign vocal cord lesions after microsurgery. Granuloma is strongly associated with the postoperative recurrence of benign vocal cord lesions.
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Aim: To evaluate changes in the surface roughness and morphology of a nanofilled composite following toothbrushing with a whitening (WT) or regular toothpaste (RT), alone or combined with 35% hydrogen peroxide bleaching (HP). Methods: Seventy disc-shaped nanofilled composite (Filtek Z350XT) specimens were randomly divided into groups (n=10): WT, RT, TB (without toothpaste control) or the combinations WT/ HP, RT/HP, TB/HP and HP. All groups underwent toothbrushing simulation (60,000 cycles) and bleaching treatment (4 sessions). Mean surface roughness (Ra, µm) was measured before (T0) and after treatments (TB). Surface morphology was assessed by scanning electron microscopy (SEM) at TB. Mean Ra was analyzed using general mixed models and multiple comparisons by the Tukey-Kramer test (α=5%). Results: HP caused no surface roughness changes on the nanofilled composite after treatment (p>0.05). RT toothbrushing, combined or not with HP, increased the surface roughness (p<0.05). WT and WT/ HP protocols had no effect on the surface roughness of the composite (p>0.05). The nanofilled composite submitted to RT toothbrushing combined with HP (RT/HP) presented substantial surface alterations under SEM, showing deep depressions and round-shaped defects. Toothbrushing with RT combined with the bleaching agent increased exposure of the inorganic fillers. Conclusion: WT toothbrushing, regardless of HP combination, or the single HP protocol had no effect on the surface roughness of the nanofilled composite. However, RT combined with HP negatively affected surface roughness and presented the most noticeable surface changes among groups
Subject(s)
Tooth Bleaching , Toothpastes , Microscopy, Electron, Scanning , Composite Resins , Hydrogen PeroxideABSTRACT
Objective: to analyze the integrity of N95/PFF2 masks in relation to fiber morphology, porosity, cracks and micro holes, as well as identify visible damage to their structure and components, after seven- and fifteen-day reuse protocols. Method: cross-sectional study. Structural and morphological characteristics of a new N95/PFF2 mask were analyzed in comparison with N95/PFF2 masks (n=10) used in seven- and fifteen-day protocols, through visual inspection and scanning electron microscopy. Results: upon visual inspection, following the seven-day protocol, 40% and 60% of the N95/PFF2 masks showed, respectively, personal identification marks and external and internal dirt. Additionally, 20% exhibited loosening and/or tearing of the straps, while 100% showed some type of damage to the nose clips. In the fifteen-day protocol, all N95/PFF2 masks had dirt, loose straps and damaged nose clips, and 80% had folds. Electronic microscopy revealed an increase in pores and loosening in the weaves from seven days onwards, extending up to fifteen days, with the presence of micro holes and residues. Conclusion: the reuse of N95/PFF2 masks affects their structural and morphological integrity. It is crucial to carry out tests to measure the impact of this practice on the safety of health professionals.
Objetivo: analizar la integridad de mascarillas N95/PFF2 con relación a la morfología de las fibras, porosidad, grietas y microagujeros, así como identificar daños visibles en su estructura y componentes, luego de protocolos de reutilización de siete y quince días. Método: estudio transversal. Se analizaron las características estructurales y morfológicas de una mascarilla N95/PFF2 nueva en comparación con las mascarillas N95/PFF2 (n=10) utilizadas en protocolos de siete y quince días, mediante inspección visual y microscopía electrónica de barrido. Resultados: tras la inspección visual, siguiendo el protocolo de siete días, el 40% y el 60% de las mascarillas N95/PFF2 mostraron, respectivamente, marcas de identificación personal y suciedad externa e interna. Además, el 20% presentó aflojamiento y/o desgarro de las correas de sujeción, mientras que el 100% presentó algún tipo de daño en los clips nasales. En el protocolo de quince días, todas las mascarillas N95/PFF2 tenían suciedad, correas de sujeción sueltas y clips nasales dañados, y el 80% tenía pliegues. La microscopía electrónica reveló un aumento de poros y aflojamiento en las tramas a partir de los siete días, extendiéndose hasta los quince días, con presencia de microagujeros y residuos. Conclusión: la reutilización de las mascarillas N95/PFF2 compromete su integridad estructural y morfológica. Es crucial realizar pruebas para medir el impacto de esta práctica en la seguridad de los profesionales de la salud.
Objetivo: analisar a integridade das máscaras N95/PFF2 em relação à morfologia das fibras, porosidade, fissuras e micro furos, bem como identificar danos visíveis em sua estrutura e componentes, após protocolos de reutilização de sete e quinze dias. Método: estudo transversal. Características estruturais e morfológicas de uma máscara N95/PFF2 nova foram analisadas em comparação com máscaras N95/PFF2 (n=10) utilizadas em protocolos de sete e quinze dias, por meio da inspeção visual e microscopia eletrônica de varredura. Resultados: na inspeção visual, seguindo o protocolo de sete dias, 40% e 60% das máscaras N95/PFF2 apresentaram, respectivamente, marcas de identificação pessoal e sujidades externas e internas. Além disso, 20% exibiram afrouxamento e/ou rompimento das tiras de fixação, enquanto 100% mostraram algum tipo de dano nos clipes nasais. No protocolo de quinze dias, todas as máscaras N95/PFF2 apresentavam sujidade, tiras de fixação frouxas e clipes nasais comprometidos; 80% possuíam dobras. A microscopia eletrônica revelou aumento dos poros e afrouxamento nas tramas a partir de sete dias, ampliando-se até quinze dias, com presença de micro furos e detritos. Conclusão: a reutilização das máscaras N95/PFF2 compromete a integridade estrutural e morfológica. É crucial realizar testes para mensurar o impacto dessa prática na segurança dos profissionais de saúde.
Subject(s)
Microscopy, Electron, Scanning , Occupational Health , Health Personnel , Equipment Reuse , Personal Protective Equipment , N95 RespiratorsABSTRACT
Purpose: To evaluate, by quantitative and qualitative methods, the glomerular ultrastructure in Wistar rats fed a cafeteria diet. Methods: Male Wistar rats were divided into two groups at 21 days of age: control (C, n = 10) and cafeteria diet (CAF, n = 8). The animals were followed up until 5 months of age, followed by euthanasia. The blood, kidneys, and fat depositsepididymal, retroperitoneal, and subcutaneouswere extracted and analyzed. Data were analyzed by Student's t test, and p < 0.05 was considered statistically significant. Results: The cafeteria diet promoted glucose intolerance, hyperglycemia (p < 0.0001), and deposition of retroperitoneal fat (p < 0.005). Scanning electron microscopy revealed that the length of the foot process was similar in both groups. The quantitative analyses by transmission electron microscopy revealed that the cafeteria diet reduced the thickness of the glomerular basement membrane (p < 0.05). Conclusions: The intake of lipids and simple carbohydrates were found to be associated with alteration in the glomerular ultrastructure. However, more studies are needed to evaluate not only the effects of high-protein and high-fat diets on components of the glomerular filtration barrier, but also renal physiology.
Subject(s)
Animals , Rats , Microscopy, Electron, Scanning , Rats, Wistar , Diet , KidneyABSTRACT
ABSTRACT BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare and heterogeneous disease that is difficult to diagnose and requires complex and expensive diagnostic tools. The saccharin transit time test is a simple and inexpensive tool that may assist in screening patients with PCD. OBJECTIVES: This study aimed to compare changes in the electron microscopy findings with clinical variables and saccharin tests in individuals diagnosed with clinical PCD (cPCD) and a control group. DESIGN AND SETTING: An observational cross-sectional study was conducted in an otorhinolaryngology outpatient clinic from August 2012 to April 2021. METHOD: Patients with cPCD underwent clinical screening questionnaires, nasal endoscopy, the saccharin transit time test, and nasal biopsy for transmission electron microscopy. RESULTS: Thirty-four patients with cPCD were evaluated. The most prevalent clinical comorbidities in the cPCD group were recurrent pneumonia, bronchiectasis, and chronic rhinosinusitis. Electron microscopy confirmed the clinical diagnosis of PCD in 16 of the 34 (47.1%) patients. CONCLUSION: The saccharin test could assist in screening patients with PCD due to its association with clinical alterations related to PCD.
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Aim: The aim of the study was to evaluate the cleaning of mandibular incisors with WaveOne Gold® (WO) under different preparation techniques. Methods: A total of 210 human mandibular incisors were selected and divided into seven groups (n = 30), prepared by WO single-files (Small 20/.07 WOS; Primary 25/.07 WOP; Medium 35/.06 WOM; or Large 45/.05 - WOL) and sequential-file techniques (WOS to WOP; WOS to WOM; and WOS to WOL). Further subdivision was made according to irrigation protocol: control group (manual irrigation - CON), E1 Irrisonic® - EIR, and EDDY® - EDD. Debris removal and the smear layer were evaluated by scanning electron microscopy. Data were analyzed by using Spearman's correlation test. The significance level was set at 5%. Results: For debris and smear layer removal, WOS and WOP, EIR differed from CON and EDD (p <0.05). Conclusion: Regardless of the instrumentation used, the agitation of the irrigant solution provided better cleanability. These findings reinforce the need for agitation techniques as adjuvants in cleaning root canal systems in mandibular incisors
Subject(s)
Root Canal Irrigants , Microscopy, Electron, Scanning , Root Canal Preparation , EndodonticsABSTRACT
Abstract Panitumumab is a monoclonal antibody against the epidermal growth factor receptor used in metastatic colorectal cancer; in addition to tumor cells, it acts on epidermal keratinocytes and on the outer root sheath and presents skin toxicity in up to 90% of cases. A scanning electron microscope was used to examine the eyelashes and hairs of a 65-year-old patient with eyelash trichomegaly, curly hair, and paronychia undergoing treatment with panitumumab. Grooving in the hair shafts were identified, which were more evident in the eyelashes. Similar to oral epidermal growth factor inhibitors (erlotinib and gefitinib), panitumumab can cause acquired pili canaliculi.
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Objective:To investigate age-related histological and ultrastructural changes of the pancreas in Sprague-Dawley(SD)rats, and to provide a theoretical basis for the high incidence of pancreatic diseases in the elderly.Methods:Thirty 6-month-old specific pathogen-free male SD rats were fed until 6, 12, 18 and 25 months of age.Five rats of each age group were randomly selected, killed and then sampled to make histological(HE staining)and electron microscopic sections to observe age-related changes in pancreatic histology and ultrastructure.Results:The pancreatic tissue of rats showed increasing fibrosis with age, especially around the duct.Fat infiltration of the pancreatic tissue also increased with age( H=15.88, P=0.001). With the increase of age, the number(density)of pancreatic islets decreased gradually( F=3.55, P=0.039), but the average cross-sectional area of islets increased significantly( F=7.76, P=0.002), and the round and oval islets became irregular.Nuclear pyknosis, mitochondrial dehydration, mitochondrial swelling, and dilatation and loose organization of rough endoplasmic reticula were observed in the cytoplasm of pancreatic acinar cells and islet beat cells in aged rats.With the increase of age, the number of zymogen granules at the apical pole of pancreatic acinar cells of rats decreased( F=9.73, P<0.001), and the average area and total area of granules were significantly decreased( F=6.51, P=0.001; F=22.18, P<0.001); The number of non-senescent mitochondria and senescent mitochondria in the cytoplasm of acinar cells increased significantly( H=8.22, P=0.045; H=32.95, P<0.001); The amount of proinsulin in islet beta cells was significantly decreased( F=16.20, P<0.001). Conclusions:With aging, the rat pancreas exhibits a series of degenerative manifestations(stromal hyperplasia, adipose tissue infiltration, decreased numbers of zymogen granules in acinar cells, increases in the number of senescent mitochondria, reduced islets and reduced proinsulin in islet beta cells), while there are some compensatory phenomena(increasing numbers of islets and non-senescent mitochondria).
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Abstract This study evaluate shaping ability of heat-treated NiTi-alloy instruments associated with different final irrigation protocols in flattened root canals. Thirty human mandibular incisors with flattened root canals were divided into 5 groups (n = 10): (XP) Original Protocol XP-endo Shaper; (XP-WT) Original Protocol XP-endo Shaper with working time variation; (XP-K) XP-endo Shaper with kinematics variation; (XP-WTK) XP-endo Shaper with kinematics and working time variations; (Hyflex) Hyflex CM. For the variation in working time protocols the same sample of the XP-endo Shaper groups with and without kinematic variation were used. To evaluate final irrigation protocols, groups 1, 3 and 5 were submitted to 3 protocols: (NI) No irrigation (n = 2); (CI) conventional irrigation (n = 4), and (EndoVac) irrigation (n = 4). The samples were scanned by microcomputed tomography and prepared for scanning electron microscopy evaluation. Quantitative data were evaluated using the parametric ANOVA test, with statistical significance level set at 5%, and qualitative data obtained were compared to establish the agreement between examiners through the Kappa test. It was observed that in the analysis of XP-endo Shaper protocols, the additional working time did not cause difference in any of parameters evaluated (p > 0.05) in relation to time recommended by manufacturer. Compared to Hyflex, XP-K showed highest mean volume increase (p < 0.05) and lowest percentage of untouched walls (p < 0.05). In the qualitative evaluation, final irrigation protocol with EndoVac provided the best cleaning results when associated with XP-K and with Hyflex. Thus, supplementary techniques are effective tools to enhance cleaning and to promote higher touch of walls during root canal preparation.
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ABSTRACT Objective: To analyze the microbiological and microstructural part of indwelling urinary catheters and their association with urinary tract infection prevention. Method: This is a cross-sectional study, from June to December 2020, in which 42 indwelling urinary catheter tips and sterile urine samples were collected for analysis of crystals in optical microscopy and biofilms in scanning electron microscopy. Culture analysis and specification of the type of bacteria were performed. Results: It was found that 35.71% of the samples had mature biofilm adhered to the catheter tip. Biofilms of Proteus mirabilis, Enterococcus faecalis, Staphylococcus epidermidis, Enterococcus faecium and Enterobacter cloacae stood out. The presence of magnesium-ammonium-phosphate crystal was associated with the presence of urinary tract infection and with Proteus mirabilis. There was a significant association (p = 0.001) between the use of prophylactic antibiotics versus urine culture >105 CFU/mL. Conclusion: The analyzes contributed to clinical practice, as it reinforces the development of effective and monitored strategies on cultures and urinary tract infection prevention associated with indwelling urinary catheters.
RESUMEN Objetivo: Analizar la parte microbiológica y microestructural de los catéteres urinarios permanentes y su asociación con la prevención de la infección del tracto urinario. Método: Transversal, de junio a diciembre de 2020, en el que se recolectaron 42 puntas de sonda urinaria permanente y muestras de orina estéril para análisis de cristales en microscopía óptica y biopelículas en microscopía electrónica de barrido. Se realizaron análisis de cultivo y especificación del tipo de bacteria. Resultados: Se encontró que el 35,71% de las muestras presentaban biopelícula madura adherida a la punta del catéter. Se destacaron las biopelículas de Proteus mirabilis, Enterococcus faecalis, Staphylococcus epidermidis, Enterococcus faecium y Enterobacter cloacae. La presencia de cristales de fosfato de magnesio-amonio se asoció con la presencia de infección del tracto urinario y con Proteus mirabilis. Hubo una asociación significativa (p = 0,001) entre el uso de antibióticos profilácticos versus urocultivo >105 UFC/mL. Conclusión: Los análisis contribuyeron a la práctica clínica, ya que refuerzan el desarrollo de estrategias efectivas y monitoreadas sobre cultivos y prevención de la infección del tracto urinario asociada a los catéteres urinarios permanentes.
RESUMO Objetivo: Analisar a parte microbiológica e microestrutural dos cateteres vesicais de demora e sua associação com a prevenção de infecção do trato urinário. Método: Transversal, entre junho e dezembro de 2020, em que foram coletadas 42 pontas cateteres vesicais de demora e amostras de urina estéril para análise de cristais em microscopia óptica e de biofilmes em microscopia eletrônica de varredura. Fez-se analise de cultura e especificação do tipo de bactérias. Resultados: Verificou-se que 35,71% das amostras apresentaram o biofilme maduro aderido à ponta do cateter. Destacaram-se biofilmes de Proteus mirabilis, Enterococcus faecalis, Staphylococcus epidermidis, Enterococcus faecium e Enterobacter cloacae. A presença do cristal magnésio-amônio-fosfato foi associada à presença de infecção do trato urinário e ao Proteus mirabilis. Verificou-se associação significativa (p = 0,001) entre o uso de antibiótico profilático versus a urocultura >105 UFC/mL. Conclusão: As análises contribuíram para a prática clínica, pois reforçam a elaboração de estratégias efetivas e monitoradas sobre culturas e prevenção de infecção do trato urinário associada ao cateter vesical de demora.
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Urinary Tract Infections , Urinary Catheters , Microscopy, Electron, Scanning , Public Health , Public Health SurveillanceABSTRACT
Aim: To compare the marginal fit of lithium disilicate CAD/CAM crowns and heat-pressed crowns fabricated using milled wax patterns, and evaluate its effect on stress distribution in implantsupported rehabilitation. Methods: A CAD model of a mandibular first molar was designed, and 16 lithium disilicate crowns (8/group) were obtained. The crown-prosthetic abutment set was evaluated in a scanning electron microscopy. The mean misfit for each group was recorded and evaluated using Student's t-test. For in silico analysis, a virtual cement thickness was designed for the two misfit values found previously, and the CAD model was assembled on an implant-abutment set. A load of 100 N was applied at 30° on the central fossa, and the equivalent stress was calculated for the crown, titanium components, bone, and resin cement layer. Results: The CAD/CAM group presented a significantly (p=0.0068) higher misfit (64.99±18.73 µm) than the heat-pressed group (37.64±15.66 µm). In silico results showed that the heat-pressed group presented a decrease in stress concentration of 61% in the crown and 21% in the cement. In addition, a decrease of 14.5% and an increase of 7.8% in the stress for the prosthetic abutment and implant, respectively, was recorded. For the cortical and cancellous bone, a slight increase in stress occurred with an increase in the cement layer thickness of 5.9% and 5.7%, respectively. Conclusion: The milling of wax patterns for subsequent inclusion and obtaining heat-pressed crowns is an option to obtain restorations with an excellent marginal fit and better stress distribution throughout the implant-abutment set
Subject(s)
Microscopy, Electron, Scanning , Computer-Aided Design , Dental Marginal Adaptation , Dental Prosthesis, Implant-Supported , Finite Element Analysis , Dental MaterialsABSTRACT
Abstract Lipoid proteinosis is a rare autosomal recessive disease, characterized by hyaline deposits of PAS-positive material in tissues due to mutations in the ECM1 gene. This study evaluated the ultrastructure of the skin of a 6-year-old child affected by this condition. The light microscopy identified PAS-positive hyaline deposits, which were more intense in the papillary dermis. Scanning electron microscopy of the dermis showed a compact papillary dermis and fibrillar deposits in the middle dermis. Transmission electron microscopy clearly showed the deposition of fibrillar material in the dermis, forming clusters adherent to elastic fibers, between the collagen bundles and the collagen fibers, and also filling up the cytoplasm of dermal fibroblasts.
Subject(s)
Humans , Child , Lipoid Proteinosis of Urbach and Wiethe , Skin , Extracellular Matrix Proteins , Collagen , Hyalin , MicroscopyABSTRACT
Abstract Cutis rhomboidalis nuchae was assessed in a 65-year-old patient. Optical microscopy showed basophilic agglomerations in the reticular dermis with decreased elastic fibers. Trans- mission electron microscopy showed elongated, curved and fragmented structures, and in their interior the presence of electron-dense lumps was reduced and irregular, similar to modified elastic fibers, whereas the collagen fibers had a normal aspect. Scanning electron microscopy showed deposits between the bundles of collagen, resembling pebbles or stones. These findings demonstrate that, at one stage of the disease, the collagen remains normal and the alterations are seen in the elastic tissue.
Subject(s)
Humans , Aged , Skin Diseases , Microscopy, Electron, Scanning , Dermis , Microscopy, Electron, Transmission , Elastic TissueABSTRACT
Background Acute tubulointerstitial nephritis (ATIN) is a very rare paraneoplastic manifestation in patients with multiple myeloma (MM). It is an uncommon pattern of renal disease in such patients. Case presentation We report a case of an 82-year-old male who was admitted with acute kidney injury. Renal biopsy showed typical findings of light chain-associated ATIN with scattered inflammatory cells in the interstitium and associated active tubulitis. No other common manifestations of MM were present at the time of presentation, including hypercalcemia, hyperuricemia, proteinuria, bone pain or lytic bone lesions. Subsequent immunoassays revealed significant serum lambda light chain burden and Bence Jones protein in urine. Immunofluorescence demonstrated linear tubular basement membranes with positive staining for lambda light chain (3+). Electron microscopy (EM) further showed interstitial edema and inflammation. All the aforementioned findings are consistent with ATIN and supported the diagnosis of MM. Conclusions In conclusion, light chain-associated ATIN should be considered in the differential diagnosis of acute interstitial nephritis. Henceforth, serum free light chains as well as serum and urine protein electrophoresis should be included in the workup of such patients.
Subject(s)
Humans , Male , Aged, 80 and over , Multiple Myeloma/complications , Nephritis, Interstitial/complications , Proteinuria , Hyperuricemia , Diagnosis, Differential , Electrophoresis , Acute Kidney Injury , HypercalcemiaABSTRACT
Objetivos: Avaliar três protocolos de irrigação final para remoção de detritos e material obturador de istmos simulados. Métodos: Setenta e oito pré-molares foram preparados com o sistema WaveOne Gold 45.05. Os dentes foram seccionados longitudinalmente e um istmo padronizado foi confeccionado no terço apical. Seis raízes foram utilizadas como controle negativo. Os espécimes foram randomizados em dois grupos principais (n=36). Trinta e seis raízes tiveram o istmo preenchido com detritos e as outras trinta e seis raízes foram obturadas com guta-percha e cimento endodôntico, por meio da técnica híbrida de Tagger. Cada grupo foi dividido em três subgrupos (n=12), de acordo com o protocolo de irrigação final: Easy Clean; irrigação ultrassônica passiva (PUI); e XP Clean. A ativação do NaOCl 2,5% pelo Easy Clean foi realizada em três ciclos de vinte segundos; e pelo XP Clean, por um minuto em movimento reciprocante e contínuo, respectivamente. No grupo PUI, o irrigante foi ativado em três períodos de vinte segundos. Resultados: Não foi encontrada associação entre os escores de remoção de detritos e os protocolos de irrigação (p=0,165). Foi observada associação entre os escores de remoção do material obturador e os protocolos de irrigação final (p<0,05). Conclusões: Os protocolos de irrigação final foram efetivos para a remoção de detritos, mas não para remoção de material obturador de istmos no terço apical (AU).
This study aimed to assess three final irrigation protocols on debris and filling removal from simulated irregularities. Methods: Seventy-eight mandibular premolars were prepared with WaveOne Gold system 45.05, splitted longitudinally, and a standardized groove was performed in the apical portion of the canals. Six roots served as negative control. The roots were randomly divided into two main groups (n = 36). The grooves were filled with dentin debris in thirty six roots. The others thirty-six were filled with gutta-percha and endodontic sealer using Tagger hybrid technique. Each main group was then divided into three groups (n = 12) according to the final irrigation protocol: Easy Clean, passive ultrasonic irrigation (PUI), and XP Clean. In Easy Clean 2.5% NaOCl activation was performed for 3 cycles of 20 seconds and XP Clean for one minute under reciprocating and continuous rotary motion and continuous rotary motion, respectively. In the PUI group, the irrigant was activated in three periods of 20 seconds. Results: No association was found among the scores of debris removal and the irrigation protocols (p = .165). An association was observed among the filling material removal scores and irrigation protocols (p< .05). Conclusion: Easy Clean, PUI and XP Clean were effective for dentin debris removal, but did not for filling material from artificial grooves in the apical third (AU).
Subject(s)
Bicuspid , Microscopy, Electron, Scanning , Efficacy , LiftingABSTRACT
Introducción. El nuevo coronavirus causante de un brote de enfermedad respiratoria aguda en China en diciembre de 2019 se identificó como SARS-CoV-2. La enfermedad, denominada COVID-19, fue declarada pandemia por la Organización Mundial de la Salud (OMS). El primer caso de COVID-19 en Colombia se reportó el 6 de marzo de 2020; en este estudio se caracterizó un aislamiento temprano del virus SARS-CoV-2 de una muestra recolectada en abril de 2020. Objetivos. Describir y caracterizar una cepa temprana a partir de un aislamiento de SARS-CoV-2 durante la pandemia en Colombia. Materiales y métodos. Se obtuvo una muestra de un paciente con COVID-19 confirmada por qRT-PCR; la muestra fue inoculada en diferentes líneas celulares hasta la aparición del efecto citopático. Para confirmar la presencia de SARS-CoV-2 en el cultivo, se utilizó la qRT-PCR a partir de los sobrenadantes, la inmunofluorescencia indirecta (IFI) en células Vero-E6, así como microscopía electrónica y secuenciación de nueva generación (next-generation sequencing). Resultados. Se confirmó el aislamiento de SARS-CoV-2 en células Vero-E6 por la aparición del efecto citopático tres días después de la infección, así como mediante la qRT-PCR y la IFI positiva con suero de paciente convaleciente positivo para SARS-CoV-2. Además, en las imágenes de microscopía electrónica de trasmisión y de barrido de células infectadas se observaron estructuras compatibles con viriones de SARS-CoV-2. Por último, se obtuvo la secuencia completa del genoma, lo que permitió clasificar el aislamiento como linaje B.1.5. Conclusiones. La evidencia presentada en este artículo permite confirmar el primer aislamiento de SARS-CoV-2 en Colombia. Además, muestra que esta cepa se comporta en cultivo celular de manera similar a lo reportado en la literatura para otros aislamientos y que su composición genética está acorde con la variante predominante en el mundo. Finalmente, se resalta la importancia que tiene el aislamiento viral para la detección de anticuerpos, para la caracterización genotípica y fenotípica de la cepa y para probar compuestos con potencial antiviral.
Introduction: SARS-CoV-2 has been identified as the new coronavirus causing an outbreak of acute respiratory disease in China in December, 2019. This disease, currently named COVID-19, has been declared as a pandemic by the World Health Organization (WHO). The first case of COVID-19 in Colombia was reported on March 6, 2020. Here we characterize an early SARS-CoV-2 isolate from the pandemic recovered in April, 2020. Objective: To describe the isolation and characterization of an early SARS-CoV-2 isolate from the epidemic in Colombia. Materials and methods: A nasopharyngeal specimen from a COVID-19 positive patient was inoculated on different cell lines. To confirm the presence of SARS-CoV-2 on cultures we used qRT-PCR, indirect immunofluorescence assay, transmission and scanning electron microscopy, and next-generation sequencing. Results: We determined the isolation of SARS-CoV-2 in Vero-E6 cells by the appearance of the cytopathic effect three days post-infection and confirmed it by the positive results in the qRT-PCR and the immunofluorescence with convalescent serum. Transmission and scanning electron microscopy images obtained from infected cells showed the presence of structures compatible with SARS-CoV-2. Finally, a complete genome sequence obtained by next-generation sequencing allowed classifying the isolate as B.1.5 lineage. Conclusion: The evidence presented in this article confirms the first isolation of SARS-CoV-2 in Colombia. In addition, it shows that this strain behaves in cell culture in a similar way to that reported in the literature for other isolates and that its genetic composition is consistent with the predominant variant in the world. Finally, points out the importance of viral isolation for the detection of neutralizing antibodies, for the genotypic and phenotypic characterization of the strain and for testing compounds with antiviral potential.
Subject(s)
Coronavirus Infections , Microscopy, Electron , Fluorescent Antibody Technique, Indirect , Severe Acute Respiratory Syndrome , Severe acute respiratory syndrome-related coronavirus , High-Throughput Nucleotide SequencingABSTRACT
Novel coronavirus (SARS-CoV-2) is found to cause a large outbreak started from Wuhan since December 2019 in China and SARS-CoV-2 infections have been reported with epidemiological linkage to China in 25 countries until now. We isolated SARS-CoV-2 from the oropharyngeal sample obtained from the patient with the first laboratory-confirmed SARS-CoV-2 infection in Korea. Cytopathic effects of SARS-CoV-2 in the Vero cell cultures were confluent 3 days after the first blind passage of the sample. Coronavirus was confirmed with spherical particle having a fringe reminiscent of crown on transmission electron microscopy. Phylogenetic analyses of whole genome sequences showed that it clustered with other SARS-CoV-2 reported from Wuhan.