RESUMEN
OBJECTIVE: Human brown adipose tissue (BAT) has gained considerable attention as a potential therapeutic target for obesity and its related cardiometabolic diseases; however, whether the gut microbiota might be an efficient stimulus to activate BAT metabolism remains to be ascertained. We aimed to investigate the association of fecal microbiota composition with BAT volume and activity and mean radiodensity in young adults. METHODS: 82 young adults (58 women, 21.8 ± 2.2 years old) participated in this cross-sectional study. DNA was extracted from fecal samples and 16S rRNA sequencing was performed to analyse the fecal microbiota composition. BAT was determined via a static 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography scan (PET/CT) after a 2 h personalized cooling protocol. 18F-FDG uptake was also quantified in white adipose tissue (WAT) and skeletal muscles. RESULTS: The relative abundance of Akkermansia, Lachnospiraceae sp. and Ruminococcus genera was negatively correlated with BAT volume, BAT SUVmean and BAT SUVpeak (all rho ≤ - 0.232, P ≤ 0.027), whereas the relative abundance of Bifidobacterium genus was positively correlated with BAT SUVmean and BAT SUVpeak (all rho ≥ 0.262, P ≤ 0.012). On the other hand, the relative abundance of Sutterellaceae and Bifidobacteriaceae families was positively correlated with 18F-FDG uptake by WAT and skeletal muscles (all rho ≥ 0.213, P ≤ 0.042). All the analyses were adjusted for the PET/CT scan date as a proxy of seasonality. CONCLUSION: Our results suggest that fecal microbiota composition is involved in the regulation of BAT and glucose uptake by other tissues in young adults. Further studies are needed to confirm these findings. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov no. NCT02365129 (registered 18 February 2015).
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Microbiota , Tomografía Computarizada por Tomografía de Emisión de Positrones , Adulto , Femenino , Humanos , Adulto Joven , Tejido Adiposo Pardo/diagnóstico por imagen , Tejido Adiposo Pardo/metabolismo , Estudios Transversales , Fluorodesoxiglucosa F18 , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Tomografía de Emisión de Positrones , ARN Ribosómico 16S/genéticaRESUMEN
The objective of this study was to compare different cephalometric variables in adult patients with class III malocclusions before and after treatment, in order to determine which variables are indicative of orthodontic camouflage or orthognathic surgery. The cases of 156 adult patients were assessed: 77 treated with orthodontic camouflage and 79 treated with orthodontics and orthognathic surgery. The following cephalometric variables were measured on pre-treatment (T1) and post-treatment (T2) lateral cephalograms: sella-nasion-A-point (SNA), sella-nasion-B-point (SNB), and A-point-nasion-B-point (ANB) angles, Wits appraisal, facial axis angle, mandibular plane angle, upper and lower incisor inclination, and inter-incisal angle. There were statistically significant differences in cephalometric variables before and after treatment between the two groups. The percentage of normal pre-treatment measurements in the camouflage orthodontics group was 30.7%, which worsened slightly to 28.4% post-treatment. However in the group receiving surgery, this was 24.5% pre-treatment, improving to 33.5% after surgery. SNA, SNB, Wits appraisal, lower incisor inclination, and inter-incisal angle showed differences between the two groups before and after treatment. Wits appraisal, lower incisor inclination, and inter-incisal angle were indicative of one or other treatment. Upper and lower incisor decompensation in both groups did not reach ideal values, which impeded complete skeletal correction in 52% of surgical cases.
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Cefalometría , Maloclusión de Angle Clase III/diagnóstico por imagen , Maloclusión de Angle Clase III/terapia , Ortodoncia Correctiva , Procedimientos Quirúrgicos Ortognáticos , Adulto , Puntos Anatómicos de Referencia , Estudios Transversales , Femenino , Humanos , Masculino , Resultado del TratamientoRESUMEN
The aim of this work was to determine the influence of the present phases and the chemical composition on the corrosion behavior and the nickel ion release of the NiTi orthodontic archwires. Eight Ni-Ti archwires from six commercial brands, in the as-received condition, were studied. The chemical composition, roughness, microstructure and the proportion of the phases as well as the corrosion behavior were analyzed for each archwire. The nickel ion release was characterized in artificial saliva immersion settings ranging up to 4 weeks. The results show that the presence of the martensitic phase improves corrosion resistance and significantly decreases Ni release into exterior medium in comparison with the austenitic specimens. In spite of the partial loss of superelasticity produced in the martensitic phase, it could be of great interest for biomedical applications, as it could minimize sensitization and allergies and improve biocompatibility and corrosion resistance of NiTi shape memory alloys.
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Cementos Dentales/química , Níquel/química , Titanio/química , Corrosión , Técnicas Electroquímicas , Níquel/análisis , Saliva Artificial/química , Espectrofotometría AtómicaRESUMEN
A potential new Ni-free Ti alloy for biomedical applications was assessed in order to investigate the superelastic behavior, corrosion resistance and the biocompatibility. The alloy studied was Ti19.1Nb8.8Zr. The chemical composition was determined by X-ray microanalysis, the thermoelastic martensitic transformation was characterized by high sensitivity calorimeter. The critical stresses were determined by electromechanical testing machine and the corrosion behavior was analyzed by potentiostatic equipment in artificial saliva immersion at 37°C. The results were compared with six different NiTi orthodontic archwire brands. The biocompatibility was studied by means of cultures of MG63 cells. Ni-free Ti alloy exhibits thermoelastic martensitic transformation with Ms=45°C. The phase present at 37°C was austenite which under stress can induce martensite. The stress-strain curves show a superelastic effect with physiological critical stress (low and continuous) and a minimal lost of the recovery around 150 mechanical cycles. The corrosion resistance improves the values obtained by different NiTi alloys avoiding the problem of the Ni adverse reactions caused by Ni ion release. Cell culture results showed that adhered cell number in new substrate was comparable to that obtained in a commercially pure Ti grade II or beta-titanium alloy evaluated in the same conditions. Consequently, the new alloy presents an excellent in-vitro response.
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Aleaciones/química , Materiales Biocompatibles/química , Corrosión , Elasticidad , Níquel/química , Temperatura , Titanio/químicaRESUMEN
The aim of this paper is to analyze the influence of the nature of the orthodontic archwires on the friction coefficient and wear rate against materials used commonly as brackets (Ti-6Al-4V and 316L Stainless Steel). The materials selected as orthodontic archwires were ASI304 stainless steel, NiTi, Ti, TiMo and NiTiCu. The array archwire's materials selected presented very similar roughness but different hardness. Materials were chosen from lower and higher hardness degrees than that of the brackets. Wear tests were carried out at in artificial saliva at 37 °C. Results show a linear relationship between the hardness of the materials and the friction coefficients. The material that showed lower wear rate was the ASI304 stainless steel. To prevent wear, the wire and the brackets have high hardness values and in the same order of magnitude.
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Análisis de Falla de Equipo , Fricción/fisiología , Alambres para Ortodoncia , Saliva Artificial/farmacología , Aleaciones Dentales/química , Análisis del Estrés Dental , Dureza/efectos de los fármacos , Humanos , Diseño de Aparato Ortodóncico , Acero Inoxidable/química , Propiedades de Superficie/efectos de los fármacos , Titanio/químicaRESUMEN
The aims of the study were to assess speed, reliability, accuracy, and reproducibility in measuring mesiodistal tooth sizes, bicanine widths, bimolar widths, and arch lengths (ALs) using cone beam computed tomography (CBCT) and to compare them with the same measurements obtained using a two-dimensional (2D) Digital Method. Plaster study models were made for 27 patients and then digitalized and measured using a 2D Digital Method. CBCTs were undertaken on the same 27 patients using the Dental Picasso Master 3D® and the images obtained were then analysed using the InVivoDental program. The correlation study of the two measuring methods, which were compared by determining the regression parameters and the values of one method as opposed to the other, show how both methods are comparable, although the mean and standard deviation of all the measurements analysed present statistically significant differences for the first upper right premolar, first upper left molar, first lower left premolar, and second lower right premolar, as well for the lower intercanine distance and lower AL. The differences, however, are less than 1 per cent. CBCT digital models are as accurate and reliable as the digital models obtained from plaster casts. The differences existing between both methods are clinically acceptable.
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Tomografía Computarizada de Haz Cónico/métodos , Modelos Dentales/normas , Diente Molar/diagnóstico por imagen , Diente/diagnóstico por imagen , Adulto , Anciano , Diente Premolar/anatomía & histología , Diente Premolar/diagnóstico por imagen , Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diente Molar/anatomía & histología , Odontometría/métodos , Reproducibilidad de los Resultados , Diente/anatomía & histologíaRESUMEN
Reuse of NiTi orthodontic wires has become increasingly common in dental clinics. For sterilization and recovery of the original superelastic properties of the wires, a heat treatment is usually performed between 500 and 600 °C. The aim of this study was to analyze the effect of these thermal treatments on the mechanical behavior and the microstructure of NiTi archwires of different compositions. A reduction of the Ni content was observed in the matrix of the thermally treated archwires, due to the formation of Ti(3)Ni(4) precipitates. The nickel-rich precipitates were observed and characterized by Transmission Electron Microscopy (TEM) and electron diffraction. They were found to alter the mechanical properties of the wires, decreasing the transformation stresses, and causing a loss of activation of the NiTi archwires. The release of nickel was higher in the original archwires than in the reused ones, due to the matrix nickel depletion caused by the precipitation of Ti(3)Ni(4).
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Elasticidad , Níquel/química , Alambres para Ortodoncia , Titanio/química , Equipo Reutilizado , Temperatura , Factores de TiempoRESUMEN
The aim of this work was to determine the influence of laser surface modification treatments on mechanical and electrochemical behavior in Ti and Ti-6Al-4V implants. For each metal, different samples were laser modified simulating the markings according to the international requirements. (It is necessary in each metallic biomaterial to mark the serial, batch and company numbers.) Microstructural changes produced by this treatment were observed: (a) the melting zone with small grain sizes and martensitic structures in above-mentioned metals and (b) the heat-affected zone (HAZ) with alpha phase in cp-Titanium with bigger grain sizes and Widmanstatten structure in Ti-6Al-4V. Positive tensile residual stress was determined by means X-ray analysis in the zones marked by laser. Furthermore, corrosion behavior was studied in a simulated body fluid at 37°C. Pitting was observed in different zones near the HAZ and the results showed a decrease of the corrosion resistance in the laser treated samples. Residual stresses and the martensitic microstructures favoured the decrease of the corrosion-fatigue life around 20% of both metals under physiological conditions.
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Materiales Biocompatibles , Corrosión , Titanio/química , Aleaciones , Rayos LáserRESUMEN
This work studies NiTi orthodontic archwires that have been treated using a new oxidation treatment for obtaining Ni-free surfaces. The titanium oxide on the surface significantly improves corrosion resistance and decreases nickel ion release, while barely affecting transformation temperatures. This oxidation treatment avoids the allergic reactions or toxicity in the surrounding tissues produced by the chemical degradation of the NiTi. In the other hand, the lack of low friction coefficient for the NiTi superelastic archwires makes difficult the optimal use of these materials in Orthodontic applications. In this study, the decrease of this friction coefficient has been achieved by means of oxidation treatment. Transformation temperatures, friction coefficient and ion release have been determined.
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Aleaciones Dentales/química , Níquel/química , Aparatos Ortodóncicos , Titanio/química , Oxidación-Reducción , Estrés MecánicoRESUMEN
OBJECTIVE: Postoperative pain is one of the most frequent complications of outpatient orthopedic surgery. We therefore studied the efficacy, feasibility, and safety of the continuous femoral nerve block as an analgesic technique for outpatient anterior cruciate ligament reconstruction. MATERIAL AND METHODS: We carried out a single-blind prospective study of ASA 1-2 patients who received a continuous femoral nerve block with 0.125% bupivacaine through an elastomeric pump to treat postoperative pain as part of a multimodal approach. Postoperative pain was assessed on a verbal numerical scale from the immediate postoperative period until 48 hours after the operation. Side effects and patient satisfaction were also assessed. RESULTS: Sixty-three patients were enrolled. The continuous femoral nerve block was effective: in the first 24 hours following surgery 90% of patients had mild or no pain, and 92% required no rescue medication. It also proved safe, as there were no significant side effects. CONCLUSION: The continuous femoral nerve block with 0.125% bupivacaine is a safe, effective option for the management of postoperative pain in outpatient anterior cruciate ligament reconstruction.
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Procedimientos Quirúrgicos Ambulatorios , Ligamento Cruzado Anterior/cirugía , Bloqueo Nervioso Autónomo/métodos , Bombas de Infusión , Dolor Postoperatorio/tratamiento farmacológico , Analgésicos no Narcóticos/administración & dosificación , Analgésicos no Narcóticos/uso terapéutico , Anestésicos Locales/administración & dosificación , Anestésicos Locales/uso terapéutico , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/uso terapéutico , Bloqueo Nervioso Autónomo/instrumentación , Bupivacaína/administración & dosificación , Bupivacaína/uso terapéutico , Quimioterapia Combinada , Elastómeros , Atención Domiciliaria de Salud , Humanos , Infusiones Intravenosas , Narcóticos/administración & dosificación , Narcóticos/uso terapéutico , Dimensión del Dolor , Dolor Postoperatorio/prevención & control , Estudios Prospectivos , Método Simple Ciego , Tramadol/administración & dosificación , Tramadol/uso terapéuticoRESUMEN
Peripheral nerve blocks have aroused increasing interest in recent years, leading to a rise in the rate of complications. At the same time noteworthy technical advances have been made in areas such as nerve stimulation and ultrasound imaging, and local anesthetics have become safer. Nevertheless, the risk of anesthetic-related systemic toxicity, which manifests with neurological symptoms that tend to be forerunners of cardiovascular ones, can not be ignored. We report 2 cases of systemic toxicity due to the use of a mixture of local anesthetics during nerve blocks for outpatient surgery.
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Anestésicos Locales/toxicidad , Bloqueo Nervioso/efectos adversos , Sistema Nervioso Periférico , Adulto , Femenino , Humanos , Persona de Mediana EdadRESUMEN
OBJECTIVE: To assess differences in the brachial plexus block in 2 groups who received the same dose of levobupivacaine: 1 group received a small volume of solution at high concentration and the other group received a large volume in solution at low concentration. MATERIAL AND METHODS: A prospective, randomized clinical trial enrolling 69 patients scheduled for wrist and/or hand surgery with a brachial plexus block with levobupivacaine in the humeral canal. Nerve stimulation was used to locate a response from the 4 terminal nerves in the brachial plexus. In the group receiving a larger volume, 10 mL of a solution of levobupivacaine at a concentration of 0.375% was used for each nerve. In the high concentration group receiving a smaller volume, levobupivacaine was used at a concentration of 0.75% in 5 mL for each nerve. Sensory latency was assessed by the pin prick technique. Motor block, the success rate (percentage), and duration of sensory and motor blockades were also evaluated. RESULTS: The full sensory block was significantly more efficacious in the large volume group than in the high concentration group (85.3% vs 51.6%, P = 0.003). A full motor block was reached in a small percentage of patients in both groups. There were no significant differences in latency or duration of block. CONCLUSIONS: The success rate was lower in the group receiving the smaller volume at a higher concentration. It is advisable to administer local anesthetics in larger volumes at lower concentrations to improve block quality. Latency and duration were similar in both groups.
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Anestésicos Locales/administración & dosificación , Plexo Braquial , Bloqueo Nervioso , Bupivacaína/administración & dosificación , Bupivacaína/análogos & derivados , Femenino , Humanos , Levobupivacaína , Masculino , Persona de Mediana Edad , Bloqueo Nervioso/métodos , Estudios ProspectivosRESUMEN
OBJECTIVE: The aim of this study was to assess the efficacy, effectiveness, technical difficulty, and clinical usefulness of the popliteal sciatic peripheral nerve block for unilateral hallus valgux surgery and to compare the posterior and lateral approaches. We also aimed to investigate patient comfort during the procedure. MATERIALS AND METHODS: This prospective, randomized trial enrolled 60 patients scheduled for unilateral hallux valgus surgery. The patients were randomly assigned to groups of 30 patients to receive a nerve block by either a posterior or lateral approach. A nerve stimulator was used to locate the response of the two branches forming the sciatic nerve--the posterior tibial nerve and the common peroneal nerve. Then, 20 mL of 0.5% ropivacaine was injected for each nerve. Variables analyzed were efficacy, complications, quality and duration of postoperative analgesia, degree of comfort while the technique was being performed, and level of satisfaction. RESULTS: The level of comfort was good for 19 patients (70%) in the posterior approach group and for 29 (97%) in the lateral approach group (P<0.05). Level of satisfaction was good or very good for 93% and 96% of the patients in the posterior and lateral approach groups, respectively. Block efficacy was excellent for 48 patients (80%), good for 9 (15%), and poor for 3 (5%), with no significant differences between the groups. CONCLUSION: Both the posterior and lateral approaches provide easy access to the sciatic nerve for performing a block. The rate of success is high and postoperative analgesia is good, with no noteworthy complications. However, the lateral approach is more comfortable for the patient.
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Bloqueo Nervioso Autónomo/métodos , Hallux Valgus/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Periodo de Recuperación de la Anestesia , Estimulación Eléctrica , Femenino , Humanos , Rodilla , Masculino , Persona de Mediana Edad , Dolor Postoperatorio/epidemiología , Dolor Postoperatorio/prevención & control , Nervio Ciático , Método Simple Ciego , Resultado del TratamientoRESUMEN
Clear cell sarcoma of the soft parts (CCSSP) is a rare and highly malignant tumor. This is a case report of a 31 years old woman who presented with a tumor in the internal face of left thigh. The tumor biopsy was suggestive of a possible malignant tumor of the peripheral nerve sheath (malignant schwannoma). Biochemical analyses, computed tomography and magnetic resonance were performed and reported a sarcoma of soft parts (CCSSP) without abnormal inguinal lymph nodes. With this diagnostic suspicion, the patient was sent to the Nuclear Medicine Service of our center where a 201Thallium scintigraphy study was performed. In this study, it showed the primary tumor together with a hot spot in the homolateral inguinal region, suggestive of the presence of a metastastic lymph node. This finding would change the surgical attitude in the patient, including inguinal lymphadenectomy. The post-surgical histological study confirmed a clear cell sarcoma of soft parts (CCSSP) with a metastatic inguinal lymph node.
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Radiofármacos , Sarcoma de Células Claras/diagnóstico por imagen , Neoplasias de los Tejidos Blandos/diagnóstico por imagen , Tendones/diagnóstico por imagen , Radioisótopos de Talio , Adulto , Diagnóstico Diferencial , Femenino , Humanos , Metástasis Linfática , Imagen por Resonancia Magnética , Neurilemoma/diagnóstico por imagen , Cintigrafía , Sarcoma de Células Claras/diagnóstico , Neoplasias de los Tejidos Blandos/diagnóstico , Talio , Muslo , Tomografía Computarizada por Rayos XRESUMEN
OBJECTIVES: To compare the effect on parameters of postanesthetic recovery of propofol and desflurane administered with high doses of remifentanil for major outpatient surgery. PATIENTS AND METHODS: Seventy patients were randomly assigned to receive propofol (target concentration 1.5-2 microg/ml) or desflurane in perfusion (end expiratory concentration 0.5 MAC) during maintenance of anesthesia with remifentanil (0.25-1 microg/kg/min). The anesthetic agents were withdrawn after surgery. We recorded the times until eye opening, respiration, tracheal extubation, ability to cough, response to verbal orders and orientation. We also recorded the time until a score of 10 on the Aldrete recovery scale was attained, pain on a visual analog scale, sedation on the Ramsay scale, and instances of nausea or vomiting during the first 24 h after surgery. RESULTS: No statistically significant differences in patient characteristics, type of surgery or anesthesia were found. Times until early signs of postanesthetic recovery (eye opening, spontaneous breathing, tracheal extubation) were significantly less (p < 0.05) in the desflurane group. The groups were similar for all other parameters compared (times until ability to cough, respond to verbal orders, orientation and a score of 10 on the Aldrete scale). Duration of stay in the postanesthetic recovery unit, time in the day surgery ward and intensity of postoperative pain were also similar. The rate of postoperative nausea or vomiting was significantly lower in the propofol group. CONCLUSION: During anesthesia with remifentanil, the administration of desflurane is associated with better psychomotor recovery parameters than is propofol, but the rate of nausea and vomiting is higher with desflurane.
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Procedimientos Quirúrgicos Ambulatorios , Periodo de Recuperación de la Anestesia , Anestésicos Intravenosos/farmacología , Piperidinas/farmacología , Propofol/farmacología , Adulto , Femenino , Humanos , Masculino , RemifentaniloRESUMEN
INTRODUCTION: Fluid preloading to prevent hypotension after epidural anesthesia has been widely questioned, although few studies have been performed in outpatients. OBJECTIVE: To evaluate the incidence and severity of hypotension, and the need for vasoactive agents after epidural anesthesia in outpatients who did or did not receive fluid preloading. PATIENTS AND METHODS: Forty patients under 55 years of age (ASA I and II) undergoing general surgery on an outpatient basis were assigned randomly to two groups of 20 according to whether they were to receive loading with Hartmann's solution or not before epidural anesthesia. All received a similar epidural dose of 2% mepivacaine. Hypotension was defined as a decrease of 20% in systolic or mean blood pressure in comparison with baseline, or absolute pressures of < 90 and 60 mmHg, respectively. Hypotension was treated with 5 mg boluses of ephedrine. RESULTS: Fourteen patients in the non-preloading group and 5 in the preloading group developed hypotension (p < 0.05). Hypotensive episodes were fewer in patients receiving preloading fluids (0.5 +/- 1.2 versus 2.0 +/- 2.4; p < 0.05). The ephedrine dose required was higher in non-preloaded patients than in preloaded ones (10.0 +/- 12.2 versus 2.6 +/- 6.3 mg; p < 0.05). Time until presentation of hypotension was longer for non-preloaded patients. CONCLUSIONS: For patients undergoing outpatient surgery, fluid preloading with 500 ml of Hartman's solution decreases both the incidence and severity of hypotension, as well as the need for vasoactive drugs after epidural anesthesia.
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Procedimientos Quirúrgicos Ambulatorios , Anestesia Epidural/efectos adversos , Efedrina/uso terapéutico , Fluidoterapia , Hipotensión/prevención & control , Complicaciones Intraoperatorias/prevención & control , Soluciones Isotónicas/administración & dosificación , Cuidados Preoperatorios , Vasoconstrictores/uso terapéutico , Adulto , Anestésicos Locales , Barorreflejo , Efedrina/administración & dosificación , Femenino , Humanos , Hipotensión/tratamiento farmacológico , Hipotensión/epidemiología , Hipotensión/etiología , Incidencia , Complicaciones Intraoperatorias/tratamiento farmacológico , Complicaciones Intraoperatorias/epidemiología , Complicaciones Intraoperatorias/etiología , Masculino , Mepivacaína , Persona de Mediana Edad , Lactato de Ringer , Resultado del Tratamiento , Vasoconstrictores/administración & dosificación , VasodilataciónRESUMEN
Airborne contamination by 99Tcm has been monitored in the Nuclear Medicine Department in our hospital to assess the risk of internal contamination to occupational workers exposed to Technegas studies. An air sampler fitted with a membrane filter was used. The optimum time for air absorption for obtaining the maximum activity in the filter was calculated. Maximum activity in the membrane filter ensures minimum uncertainty, which is especially important when low-level activities are being measured. The optimum time depends on air absorption velocity, room volume and filter efficiency for isotope collection. It tends to 1/lambda (lambda = disintegration constant for 99Tcm) for large volume and low velocity. Room activity with the air pump switched on was related to filter activity, and its variation with time was studied. Free activity in air for each study was approximately 7 x 10(-4) the activity used, and the effective half-life of the isotope in the room was 13.9 min (decay and diffusion). For a typical study (630 MBq), the effective dose to staff was 0.01 microSv when in the room for 10 min.