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1.
Rev Col Bras Cir ; 48: e20202587, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33533824

RESUMO

OBJECTIVES: the aim of this study was to compare the outcomes of a new silicone vascular prostheses with PTFE vascular prostheses, on a rabbit experimental model. METHODS: forty rabbits underwent infra-renal aorta replacement with 4 mm diameter prostheses, twenty animals with PDMS and twenty animals with PTFE (control group). Retrograde aortic angiography was performed to assess patency. Histological graft samples were examined by electron microscopy to evaluate prostheses endothelialization. RESULTS: patency rates were 100% for both grafts after 30 days; after 60 days, patency rate for PDMS was 92.3% (±7.4), and 73,8% (±13.1) at 90 days. PTFE grafts had patency rates of 87.5% (±11.7) at 60 and 90 days. No statistically significant difference was found in between groups for patency rates (p=0.62). Postoperative complications (death, paraplegia) rates (p=0.526) and aortic clamping times (p=0.299) were comparable in both groups. No statistically significant difference for stenosis was found on angiographical analysis between groups (p=0.650). Electron microscopy revealed limited anastomotic endothelial ingrowth in both prostheses. CONCLUSION: in this experimental model, PDMS and PTFE vascular prostheses had comparable outcomes and PDMS prosthesis could be used as a vascular graft.


Assuntos
Aorta/cirurgia , Prótese Vascular , Politetrafluoretileno/uso terapêutico , Silicones/uso terapêutico , Animais , Poliésteres , Coelhos
2.
J Vis Exp ; (166)2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33346198

RESUMO

External forces are an important factor in tissue formation, development, and maintenance. The effects of these forces are often studied using specialized in vitro stretching methods. Various available systems use 2D substrate-based stretchers, while the accessibility of 3D techniques to strain soft hydrogels, is more restricted. Here, we describe a method that allows external stretching of soft hydrogels from their circumference, using an elastic silicone strip as the sample carrier. The stretching system utilized in this protocol is constructed from 3D-printed parts and low-cost electronics, making it simple and easy to replicate in other labs. The experimental process begins with polymerizing thick (>100 µm) soft fibrin hydrogels (Elastic Modulus of ~100 Pa) in a cut-out at the center of a silicone strip. Silicone-gel constructs are then attached to the printed-stretching device and placed on the confocal microscope stage. Under live microscopy the stretching device is activated, and the gels are imaged at various stretch magnitudes. Image processing is then used to quantify the resulting gel deformations, demonstrating relatively homogenous strains and fiber alignment throughout the gel's 3D thickness (Z-axis). Advantages of this method include the ability to strain extremely soft hydrogels in 3D while executing in situ microscopy, and the freedom to manipulate the geometry and size of the sample according to the user's needs. Additionally, with proper adaptation, this method can be used to stretch other types of hydrogels (e.g., collagen, polyacrylamide or polyethylene glycol) and can allow for analysis of cells and tissue response to external forces under more biomimetic 3D conditions.


Assuntos
Hidrogéis/química , Imageamento Tridimensional , Microscopia , Módulo de Elasticidade , Fibrina/química , Fibrinogênio/química , Análise de Elementos Finitos , Polimerização , Silicones/química , Software , Trombina/química , Interface Usuário-Computador
3.
PLoS One ; 15(12): e0242704, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33351854

RESUMO

In this study we present a kinematic approach for modeling needle insertion into soft tissues. The kinematic approach allows the presentation of the problem as Dirichlet-type (i.e. driven by enforced motion of boundaries) and therefore weakly sensitive to unknown properties of the tissues and needle-tissue interaction. The parameters used in the kinematic approach are straightforward to determine from images. Our method uses Meshless Total Lagrangian Explicit Dynamics (MTLED) method to compute soft tissue deformations. The proposed scheme was validated against experiments of needle insertion into silicone gel samples. We also present a simulation of needle insertion into the brain demonstrating the method's insensitivity to assumed mechanical properties of tissue.


Assuntos
Injeções/estatística & dados numéricos , Modelos Estatísticos , Agulhas , Silicones/análise , Fenômenos Biomecânicos , Encéfalo/anatomia & histologia , Simulação por Computador , Humanos , Injeções/instrumentação , Injeções/métodos , Manequins , Modelos Anatômicos , Silicones/química , Estresse Mecânico
4.
Rev. Asoc. Odontol. Argent ; 108(3): 113-118, dic. 2020. ilus
Artigo em Espanhol | LILACS | ID: biblio-1147645

RESUMO

Objetivo: Analizar cualitativamente la biocompatibilidad y la capacidad osteogénica de dos selladores endodónticos a base de silicato de calcio: el biocerámico Bio-C Sealer (BIOc) y MTA Densell Sealer (MTAd). Materiales y métodos: En la tibia izquierda de 30 ratas Wistar macho se implantó un tubo de silicona obturado con BIOc. De igual forma, en la tibia derecha de cada una se implantó un tubo de silicona obturado con MTAd. Los animales fueron eutanasiados en grupos de 10 a los 7, 30 y 90 días. Las tibias fueron procesadas para su análisis histológico y analizadas con microscopía óptica. Según lo observado, fueron clasificadas en tres categorías: 1: Presencia de cápsula fibrosa sana y neoformación ósea, sin células inflamatorias; 2: Cápsula fibrosa con o sin células inflamatorias, formación inicial de trabéculas óseas y presencia de células inflamatorias en los tejidos circundantes; 3: Ausencia de cápsula y/o tejido óseo y presencia de numerosas células inflamatorias. Los resultados fueron analizados con las pruebas de McNemar y de Kruskal-Wallis (P<0,05). Resultados: A los 7 días, los tejidos en contacto con BIOc y MTAd reaccionaron según la categoría 3. A los 30 días, todos los casos correspondieron a la categoría 2. A los 90 días, los 10 implantes de BIOc fueron clasificados según la categoría 1. MTAd presentó nueve casos de categoría 1 y un caso de categoría 2. No hubo diferencias significativas entre ambos selladores dentro de cada uno de los períodos de observación (P>0,05), pero sí las hubo cuando se compararon los resultados obtenidos entre períodos de observación (P<0,05). Conclusión: Al finalizar el ensayo, Bio-C Sealer y MTA Densell Sealer se comportaron como materiales biocompatibles y osteogénicos en tibias de rata (AU)


Aim: To analyze the biocompatibility and osteogenic capacity of two silicate-based endodontic sealers, the bioceramic Bio C-Sealer (BIOc) and the MTA-based sealer MTA Densell (MTAd). Materials and methods: Silicone tubes filled with BIOc were implanted in the left tibias of 30 white male Wistar rats (one per tibia). In similar fashion, tubes filled with MTAd were implanted in the right tibias. The animals were euthanized in groups of 10 at 7, 30 and 90 days postoperatively. The tibias were removed, processed for histology and analysed under optical microscopy. The observations were classified in three categories: 1: Presence of a healthy fibrous capsule and newly formed bone trabeculae without inflammatory cells. 2: Fibrous capsule with or without inflammatory cells, initial formation of bone trabeculae and presence of inflammatory cells in the surrounding tissues. 3: Absence of a fibrous capsule and/or bone formation with the presence of numerous inflammatory cells. Data was analyzed by the McNemar and the Kruskal-Wallis test (P<0.05). Results: At 7 days: The tissues in contact with BIOc and MTAd reacted as category 3. At 30 days: All cases were classified as category 2. At 90 days: All BIOc cases were in category 1 while MTAd presented nine cases of category 1 and one case of category 2. There were no significant differences (P>0.05) between both sealants BIOc and MTAd in each period group. However, there were significant differences (P<0.05) when the results between periods were compared. Conclusion: At the end of the experiment both, BIOc and MTAd behaved as biocompatible and osteogenic materials in the rats' tibias (AU)


Assuntos
Animais , Ratos , Materiais Restauradores do Canal Radicular , Materiais Biocompatíveis , Cerâmica , Osteogênese , Silicones , Teste de Materiais , Calcarea Silicata , Ratos Wistar , Silicatos , Microscopia
5.
Facial Plast Surg ; 36(5): 517-527, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33368076

RESUMO

In Asian countries, augmentation rhinoplasty is especially common, where alloplastic implants are used much more commonly than autologous tissues. In rhinoplasty, such artificial materials include silicone, expanded polytetrafluoroethylene (ePTFE), porous high-density polyethylene (pHDPE), and acellular human dermis. As the use of implants has become increasingly common in rhinoplasty, more adverse effects such as infection, extrusion, movement, irregularities, absorption, prolonged swelling, seroma, and contracture have been recognized and reported in the literature. Surgeons should be able to recognize these probable complications and manage them successfully. Early detection and prompt management of the complication are essential for minimizing the severity of the deformity. Proper management of complications is key for the success of dorsal augmentation using alloplastic implants.


Assuntos
Implantes Dentários , Rinoplastia , Materiais Biocompatíveis/efeitos adversos , Humanos , Politetrafluoretileno/efeitos adversos , Próteses e Implantes/efeitos adversos , Rinoplastia/efeitos adversos , Silicones/efeitos adversos
6.
PLoS One ; 15(12): e0244518, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33370781

RESUMO

Spread of pathogens on contaminated surfaces plays a key role in disease transmission. Surface technologies that control pathogen transfer can help control fomite transmission and are of great interest to public health. Here, we report a novel bead transfer method for evaluating fomite transmission in common laboratory settings. We show that this method meets several important criteria for quantitative test methods, including reasonableness, relevancy, resemblance, responsiveness, and repeatability, and therefore may be adaptable for standardization. In addition, this method can be applied to a wide variety of pathogens including bacteria, phage, and human viruses. Using the bead transfer method, we demonstrate that an engineered micropattern limits transfer of Staphylococcus aureus by 97.8% and T4 bacteriophage by 93.0% on silicone surfaces. Furthermore, the micropattern significantly reduces transfer of influenza B virus and human coronavirus on silicone and polypropylene surfaces. Our results highlight the potential of using surface texture as a valuable new strategy in combating infectious diseases.


Assuntos
Bacteriófago T4/patogenicidade , Bacteriófagos/patogenicidade , Coronavirus/patogenicidade , Vírus da Influenza B/patogenicidade , Infecções Estafilocócicas/terapia , Staphylococcus aureus/patogenicidade , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Fômites/microbiologia , Fômites/virologia , Humanos , Influenza Humana/transmissão , Influenza Humana/virologia , Silicones
7.
Medicine (Baltimore) ; 99(45): e23073, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33157970

RESUMO

INTRODUCTION: Contracture of dacryocyst by an implanted lacrimal silicone tube is rare. This report describes a unique case of secondary dacryocystitis and the contracture of dacryocyst caused by a lacrimal silicone tube that was placed in the lacrimal system for 10 years. PATIENT CONCERNS: A 63-year-old female was diagnosed with chronic dacryocystitis at a local hospital and underwent surgical treatment 10 years ago. In the past month, the patient complained of persistent tearing and purulent secretion from the eyes. DIAGNOSIS: The patient was diagnosed with secondary dacryocystitis, based on clinical features and the presence of the silicone stent, granulation tissue formation, and dacryocyst contracture in the lacrimal duct, as observed by nasal endoscopy. INTERVENTIONS: For treatment, the implanted silicone tube in the patient was removed, the lacrimal duct and nasal mucosa was anastomosed, and a new lacrimal silicone tube was placed again. OUTCOMES: Following the surgery, the patient recounted that there were no symptoms, and follow-up examinations performed over a 1-month period posttreatment revealed no recurrence of obstruction or dacryocystitis. Therefore, the surgeon removed the lacrimal drainage tube and asked the patient to return to the outpatient department regularly for examination. CONCLUSION: The findings, in this case, suggest that silicone tubes are safe and effective, and can be placed in the lacrimal drainage system. However, in this patient, prolonged intubation caused chronic inflammation, granulation tissue formation, and dacryocyst contracture. Our findings could inform surgeons to consider the reasonable duration of intubation for treating cases of lacrimal obstruction, in order to avoid unnecessary complications.


Assuntos
Dacriocistite/etiologia , Ducto Nasolacrimal/cirurgia , Complicações Pós-Operatórias/etiologia , Próteses e Implantes/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Desenho de Prótese , Silicones , Fatores de Tempo
8.
Praxis (Bern 1994) ; 109(14): 1127-1133, 2020.
Artigo em Alemão | MEDLINE | ID: mdl-33109001

RESUMO

Cosmetic Breast Augmentation without Silicone Implants Abstract. Cosmetic breast augmentation procedures without silicone implants are becoming increasingly popular. Mastopexy can be adapted to the needs of the patient and usually result in an at least optical augmentation. Lipofilling is a safe procedure in reconstructive and aesthetic breast surgery and can help to restore natural appearance, compensate volume deficiencies, and correct asymmetries, that may be congenital or a consequence of prior surgeries. Cosmetic breast augmentation of very small breasts or when aiming at higher breast volumes using lipofilling only are usually combined with procedures for tissue expansion in order to increase the take rate of the injected fat. Hyaluronic acid injections is no valid alternative and are not recommended for cosmetic breast augmentation.


Assuntos
Mamoplastia , Mastectomia , Satisfação do Paciente , Mama/cirurgia , Humanos , Silicones
9.
Medicine (Baltimore) ; 99(41): e22548, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33031299

RESUMO

OBJECTIVE: To investigate the efficacy and complications that might be associated with pyrocarbon compared with silicone in patients undergoing joint replacement surgery. METHODS: The full-text papers about the clinical efficacy of pyrocarbon and silicone were retrieved from multiple databases. Review Manager version 5.0 was adopted for meta-analysis and analyses of sensitivity and bias. RESULTS: Ultimately, we studied 232 patients across eight studies that met the eligibility criteria. The meta-analysis suggested a significant difference between the pyrocarbon and silicone groups in terms of the Disabilities of the Arm, Shoulder, and Hand (DASH) score (standard mean difference (SMD) = 1.48; 95% CI [0.97, 1.99]; P = .009; P for Heterogeneity <0.00001; I = 63%); Visual Analogue Score (VAS) (SMD = 1.68; 95% CI [1.36, 1.99]; P < .00001; P for heterogeneity = 0.01; I = 61%), and the abnormal radiolucent line (RR = 6.66; 95% CI [3.19, 13.89]; P < .00001; P for heterogeneity = 0.87, I = 0%); and ossification development (RR = 0.90; 95% CI [0.56, 1.44], P = .66; P for heterogeneity = 0.94, I = 0%). CONCLUSION: This study showed that pyrocarbon might be an efficient material compared with silicone for joint replacement surgery, but resulted in poorer functional and pain outcomes compared with silicone.


Assuntos
Artroplastia de Substituição , Carbono , Prótese Articular , Silicones , Materiais Biocompatíveis , Avaliação da Deficiência , Humanos , Medição da Dor , Desenho de Prótese
10.
J Urol ; 204(4): 776-777, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32898972
11.
J Urol ; 204(4): 776, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32898973
12.
J Vasc Interv Radiol ; 31(11): 1795-1800, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32962854

RESUMO

This brief report presents 8 patients with silicone-covered metallic stent placement for ureteral strictures refractory to double-J stent placement, following kidney transplantation. Stent removal was successfully performed in 7 patients via antegrade (n = 4) or retrograde (n = 3) access 6 weeks to 6 months after stenting for elective removal (6-month interval, n = 3), urothelial hyperplasia (n = 2), or stent migration (n = 2), and their mean primary ureteral patency after stent removal was 15.4 months (range, 2-27 months). Hematuria (n = 2) and pain (n = 3) occurred, but resolved within 1 week. One stent was removed during reconstructive surgery. During follow-up of mean 22.6 months after stent removal, ureteral strictures recurred in 2 patients.


Assuntos
Cateterismo/instrumentação , Remoção de Dispositivo , Transplante de Rim/efeitos adversos , Stents Metálicos Autoexpansíveis , Silicones , Obstrução Ureteral/terapia , Adulto , Idoso , Cateterismo/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nefrostomia Percutânea , Desenho de Prótese , Recidiva , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Obstrução Ureteral/diagnóstico por imagem , Obstrução Ureteral/etiologia
13.
Arch Osteoporos ; 15(1): 149, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32964330

RESUMO

The effects of gluteal implants on bone mass remain unclear. Transgender women with ILS presented higher BMD in the hip compared with transgender women without implants, while no difference was observed in other sites. These results may be artifactual and suggest using spine/forearm sites for DXA in individuals with ILS. PURPOSE: The inappropriate use of industrial liquid silicone (ILS) injections for cosmetic purposes is practiced by some transgender women. The aim of this study was to evaluate the impact of gluteal ILS on femur BMD in transgender women. METHODS: A total of 46 trans women with and without ILS injection in the gluteal region were selected. All patients underwent clinical and hormonal evaluation, and bone mass was assessed by DXA. RESULTS: Bone mineral density (BMD) values were significantly higher in trans women with ILS (n = 23) in femoral neck and total femur when compared with trans women without implants (n = 23). Similar BMD was observed in other sites, such as lumbar spine and forearm. Good agreement was found in the evaluation of low BMD using spine/forearm or spine/femur in patients without implants (k = 0.744 and 1.000 for male and female reference database, respectively), but poor to fair index was found in patients with ILS implants (k = 0.330 and 0.646 for male and female reference database, respectively). CONCLUSIONS: In transgender women with ILS implants, poor to moderate agreement was found on BMD when comparing lumbar spine/femur DXA with an alternative site to the femur, depending on using male or female database. These results may be artifactual and suggest using spine/forearm sites for more accurate DXA assessments in trans women with ILS gluteal implants.


Assuntos
Densidade Óssea , Implantes de Mama , Pessoas Transgênero , Absorciometria de Fóton , Implantes de Mama/efeitos adversos , Feminino , Colo do Fêmur/diagnóstico por imagem , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Silicones
14.
PLoS One ; 15(9): e0239930, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986780

RESUMO

BACKGROUND: In our clinic, a substantial number of patients present with transtibial residual limb pain of no specific somatic origin. Silicone liner induced tissue compression may reduce blood flow, possibly causing residual limb pain. Thus, as a first step we investigated if the liner itself has an effect on transcutaneous oxygen pressure (TcPO2). METHODS: Persons with unilateral transtibial amputation and residual limb pain of unknown origin were included. Medical history, including residual limb pain, was recorded, and the SF-36 administered. Resting TcPO2 levels were measured in the supine position and without a liner at 0, 10, 20 and 30 minutes using two sensors: one placed in the Transverse plane over the tip of the Tibia End (= TTE), the other placed in the Sagittal plane, distally over the Peroneal Compartment (= SPC). Measurements were repeated with specially prepared liners avoiding additional pressure due to sensor placement. Statistical analyses were performed using SPSS. RESULTS: Twenty persons (9 women, 11 men) with a mean age of 68.65 years (range 47-86 years) participated. The transtibial amputation occurred on average 43 months prior to study entry (range 3-119 months). With liner wear, both sensors measured TcPO2 levels that were significantly lower than those measured without a liner (TTE: p < 0.001; SPC: p = 0.002) after 10, 20 and 30 minutes. No significant differences were found between TcPO2 levels over time between the sensors. There were no significant associations between TcPO2 levels and pain, smoking status, age, duration of daily liner use, mobility level, and revision history. CONCLUSION: Resting TcPO2 levels decreased significantly while wearing a liner alone, without a prosthetic socket. Further studies are required to investigate the effect of liner wear on exercise TcPO2 levels.


Assuntos
Cotos de Amputação/fisiopatologia , Amputação , Monitorização Transcutânea dos Gases Sanguíneos/métodos , Membro Fantasma/sangue , Descanso , Tíbia/cirurgia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/complicações , Membro Fantasma/etiologia , Fatores Sexuais , Silicones
15.
Sci Total Environ ; 740: 140136, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32927574

RESUMO

Children are exposed to many potentially toxic compounds in their daily lives and are vulnerable to the harmful effects. To date, very few non-invasive methods are available to quantify children's exposure to environmental chemicals. Due to their ease of implementation, silicone wristbands have emerged as passive samplers to study personal environmental exposures and have the potential to greatly increase our knowledge of chemical exposures in vulnerable population groups. Nevertheless, there is a limited number of studies monitoring children's exposures via silicone wristbands. In this study, we implemented this sampling technique in ongoing research activities in Montevideo, Uruguay which aim to monitor chemical exposures in a cohort of elementary school children. The silicone wristbands were worn by 24 children for 7 days; they were quantitatively analyzed using gas chromatography with tandem mass spectrometry for 45 chemical pollutants, including polychlorinated biphenyls (PCBs), pesticides, polybrominated diphenyl ethers (PBDEs), organophosphorus flame retardants (OPFRs), and novel halogenated flame-retardant chemicals (NHFRs). All classes of chemicals, except NHFRs, were identified in the passive samplers. The average number of analytes detected in each wristband was 13 ±3. OPFRs were consistently the most abundant class of analytes detected. Median concentrations of ΣOPFRs, ΣPBDEs, ΣPCBs, and dichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)) were 1020, 3.00, 0.52 and 3.79 ng/g wristband, respectively. Two major findings result from this research; differences in trends of two OPFRs (TCPP and TDCPP) are observed between studies in Uruguay and the United States, and the detection of DDT, a chemical banned in several countries, suggests that children's exposure profiles in these settings may differ from other parts of the world. This was the first study to examine children's exposome in South America using silicone wristbands and clearly points to a need for further studies.


Assuntos
Poluentes Ambientais , Retardadores de Chama/análise , Praguicidas , Criança , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Humanos , Organofosfatos , Silicones , América do Sul , Uruguai
16.
Ecotoxicol Environ Saf ; 205: 111100, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32911453

RESUMO

Compared to the general population, firefighters are known to sustain greater levels of exposure to hazardous compounds, despite their personal protective equipment, also known as turnout gear. Among the most significant toxins that firefighters are chronically exposed to are polycyclic aromatic hydrocarbons (PAHs). Additionally, firefighters have also been noted to exhibit an increased incidence of certain types of cancer. Considering a probable link between exposure to PAHs and increased rates of cancer in the fire service, we aim to document ambient chemical concentrations in the firefighter work environment. Our strategy involves the use of silicone-based wristbands that have the capacity to passively sorb PAHs. To determine if wristbands can serve as an effective chemical monitoring device for the fire service, silicone wristbands were pilot-tested as personal sampling devices for work environment risk monitoring in active-duty firefighters. Recovered wristbands underwent multiple extraction steps, followed by GC-MS analysis to demonstrate their efficacy in monitoring PAHs in the firefighter environment. Initial findings from all wristband samples taken from firefighters showed multiple exposures to various PAHs of concern for the health of the firefighters when in a fire environment. In addition to PAH monitoring, we examined known and potential sources of PAH contamination in their work environment. To that end, profiles of elevated PAH concentrations were documented at various fire stations throughout South Florida, for individual firefighters both during station duties and active fire response.


Assuntos
Poluentes Ocupacionais do Ar/análise , Bombeiros , Exposição Ocupacional/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Carcinógenos/análise , Monitoramento Ambiental , Florida , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Neoplasias , Exposição Ocupacional/estatística & dados numéricos , Silicones/análise
17.
Niger J Clin Pract ; 23(9): 1266-1273, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32913167

RESUMO

Aims: This study evaluated the effect of oxygen plasma and argon plasma treatments with different application times on tensile bonding of a silicone-based denture liner to polymethylmetacrylate (PMMA). Methods: Seven groups (n = 5) were prepared and six of them treated by argon plasma or oxygen plasma with 30s, 60s, and 120s, respectively; one group was left untreated served as control. After processing of denture liner, the specimens were deflasked and stored dry for 24 h, and they were then subjected to tensile bond strength testing. Differences in tensile bond strength values were determined using one-way ANOVA (α = 0.05). Results: Highest tensile bond strengths were observed in the oxygen plasma groups, followed by untreated group and argon plasma groups in turn in order. Tensile bond strenght were increased with time for both type of plasma applications tested. Conclusion: This study suggests that the adhesion between PMMA and denture liner is improved under conditions of oxygen plasma treatment with extended exposure time rather than argon plasma treatment.


Assuntos
Coagulação com Plasma de Argônio , Colagem Dentária/métodos , Reembasadores de Dentadura , Polimetil Metacrilato/química , Silicones/química , Resistência à Tração , Argônio , Bases de Dentadura , Humanos , Teste de Materiais , Oxigênio , Propriedades de Superfície
18.
Harefuah ; 159(9): 697-702, 2020 Sep.
Artigo em Hebraico | MEDLINE | ID: mdl-32955815

RESUMO

INTRODUCTION: Silicone is a foreign material to our body and therefore, has been found to stimulate the immune system. Silicone breast implants (SBIs), made of silicone polymer, have been used for aesthetic and medical purposes since the 1960s, and were found to trigger acute/chronic inflammation, eventually leading to the formation of fibrotic capsules on the surface of the implant. Silicone implants have been found to be associated with the development of severe and sometimes unexplained clinical manifestations such as: chronic fatigue, sleep and memory problems, widespread pain, dry mouth and eye, depression, arthralgia, myalgia, palpitations, tinnitus and hearing loss, skin rash, hair loss, vision problems, hyperhidrosis, allergic reactions, etc. Furthermore, SBIs have been found to be associated with the development of rheumatologic/autoimmune diseases and the development of rare lymphoma. The FDA has expressed concern over the years about the implications of SBIs and requested that the companies involved provide data of any concern regarding the implants. However, the companies continued to sell the implants without reporting data, as agreed. In October 2019, the FDA recommended boxed warnings describing the dangers facing women applying for SBIs such as lymphoma. Importantly, our lab recently found the presence of autoantibodies against the autonomic nervous system in the blood of women with SBIs, which might explain some of the patients' severe symptoms. Owing to the numerous data that had been accumulated (since 1960s) indicating a direct link between silicone, autoimmune diseases and cancer, we believe that the use of SBIs has been a historical medical error.


Assuntos
Implantes de Mama , Erros Médicos , Doenças Autoimunes , Feminino , Humanos , Hipersensibilidade , Silicones
19.
Rev. esp. cir. oral maxilofac ; 42(3): 139-142, jul.-sept. 2020. ilus
Artigo em Espanhol | IBECS | ID: ibc-196631

RESUMO

Actualmente las sustancias de relleno son la forma más popular para el rejuvenecimiento facial y el aumento de los tejidos. Existen varios problemas añadidos que han condicionado el aumento de las complicaciones con los materiales de relleno, que son el uso de sustancias adulteradas, la inyección de varios materiales en la misma zona o la administración por personal no entrenado/autorizado. Varias investigaciones sugieren que la ecografía de alta frecuencia (EAF) es una herramienta útil, de bajo coste y no invasiva para demostrar el tipo material de relleno e identificar el lugar de inyección y la cantidad de material inyectado. Presentamos en caso de una mujer de 64 años que presentaba edema hemifacial después de 15 años de haberse inyectado silicona líquida (SIL) en los labios, tratada con minociclina, mostrando mejoría clínica significativa


Currently injectable materials are popular for facial rejuvenation and soft tissue augmentation. There are some added problems, which have been conditioned by the increase in complications with fillers, that are the use of adulterated materials, injections of various types of substances in the same area or because administration by inexperienced/untrained professionals. Several studies suggest that high frequency ultrasound (HUS) is an economical, useful and non-invasive diagnostic tool to determine the nature and type of material and to identify the injection site and quantity of injected filler. We report a case of a 64-year-old woman who presented hemifacial swelling after 15 years of being injected with 1 infiltration of liquid injectable silicone (LIS) in the lips, treated with Minocycline, showing a significant clinical improvement


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Edema/diagnóstico por imagem , Silicones/efeitos adversos , Preenchedores Dérmicos/efeitos adversos , Assimetria Facial/etiologia , Próteses e Implantes/efeitos adversos , Prednisona/uso terapêutico , Minociclina/uso terapêutico
20.
J Am Acad Orthop Surg ; 28(15): e670-e678, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32732659

RESUMO

Outcomes research has historically been driven by single-center investigations. However, multicenter studies represent an opportunity to overcome challenges associated with single-center studies, including generalizability and adequate power. In hand surgery, most clinical trials are single-center studies, with few having randomized controls and blinding of both participants and assessors. This pervasive issue jeopardizes the integrity of evidence-based practice in the field. Because healthcare payers emphasize applying the best available evidence to justify medical services, multicenter research collaborations are increasingly recognized as an avenue for efficiently generating high-quality evidence. Although no study design is perfect, the potential advantages of multicenter trials include generalizability of the results, larger sample sizes, and a collaboration of experienced investigators poised to optimize protocol development and study conduct. As the era of single-center studies shifts toward investment in multicenter trials and clinical registries, investigators will inevitably be faced with the challenges of conducting or contributing to multicenter research collaborations. We present our experiences in conducting multicenter investigations to provide insight into this demanding and rewarding frontier of research.


Assuntos
Amputação , Artrite Reumatoide/cirurgia , Artroplastia/métodos , Medicina Baseada em Evidências , Dedos/cirurgia , Dedos/transplante , Mãos/cirurgia , Colaboração Intersetorial , Estudos Multicêntricos como Assunto , Satisfação Pessoal , Rádio (Anatomia)/lesões , Rádio (Anatomia)/cirurgia , Reimplante , Silicones , Nervo Ulnar/cirurgia , Traumatismos do Punho/cirurgia , Humanos , Resultado do Tratamento
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