Fecal microbiota composition is related to brown adipose tissue 18F-fluorodeoxyglucose uptake in young adults.

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).

Orthodontic camouflage versus orthognathic surgery for class III deformity: comparative cephalometric analysis.

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.

Influence of the microstructure on electrochemical corrosion and nickel release in NiTi orthodontic archwires.

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.

New Ni-free superelastic alloy for orthodontic applications.

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.

Friction coefficients and wear rates of different orthodontic archwires in artificial saliva.

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.

A comparison between dental measurements taken from CBCT models and those taken from a digital method.

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.

Corrosion and corrosion-fatigue behavior of cp-Ti and Ti-6Al-4V laser-marked biomaterials.

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.

Variation of the superelastic properties and nickel release from original and reused NiTi orthodontic archwires.

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).

Reduction of Ni release and improvement of the friction behaviour of NiTi orthodontic archwires by oxidation treatments.

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.

Polimorfismos del gen VDR en el riesgo de fracturas osteoporótica de cadera en una población adulta española / VDR gene polymorphisms on risk of osteoporotic hip fracture in an adult population spanish

La osteoporosis es una enfermedad esquelética compleja multifactorial con un fuerte componente genético, caracterizada por un deterioro en la microestructura ósea que causa fragilidad ósea y un incremento en el riesgo de fracturas osteoporóticas. El gen VDR podría estar fuertemente involucrado en el riesgo de fractura. El objetivo de este trabajo fue investigar la asociación entre polimorfismos del gen VDR y la susceptibilidad a fractura de cadera (FC). Se reclutaron 147 pacientes andaluces (102 con factores de riesgos de fracturas osteoporóticas y 45 con metabolismo óseo normal). El aislamiento de ADN se realizó a partir de 300 mL de sangre, genotipando 2 SNPs: BsmI y FokI mediante PCRRFLP (PCR-Restriction Fragment Length Polymorphism). Todas las fracturas fueron confirmadas por rayos-X mientras que el riesgo de fracturas a través de la escala FRAX y DMO. Los resultados se evaluaron estadísticamente, considerando significativo valores de p<0,05. La edad media de los pacientes fracturados fue de 68,5 años, cuyas frecuencias alélicas fueron 64.7% G y 68.6% C para BsmI y FokI, respectivamente. La prevalencia de estos SNPs en la población caso fueron: 43,3% GA,43.3% GG y 13,7% AA para BsmI y 49,0% CC, 39,20% CT, 11,8% TT para FokI. Las frecuencias de los alelos y genotipos no mostraron diferencias entre pacientes con riesgo de fracturas y pacientes control. Las frecuencias están acorde con las demostradas en HapMap para población europea caucásica. No se encontró ninguna asociación significativa entre estos SNPs y la susceptibilidad a las FC en la población adulta andaluza(AU)

Osteoporosis is a multifactorial complex skeletal disease with strong genetic component, characterized by a deterioration of bone microstructure that causes bone fragility and an increased risk of osteoporotic fractures. VDR gene could be strongly involved in the risk of fracture. The aim of this study was to investigate the association between VDR gene polymorphisms and susceptibility to hip fracture (HF). 147 Andalusian patients were recruited (102 with risk factors for osteoporotic fractures and 47 with normal bone metabolism). DNA isolation was performed from 300 mL of blood, genotyping 2 SNPs: BsmI and FokI by PCR-RFLP (PCR-Restriction Fragment Length Polymorphism). All fractures were confirmed by X-rays while the risk of fractures through FRAX level and BMD. The results were statistically evaluated, considering significant p-values <0.05. The average age of fractured patients was 68.5 years, whose allele frequencies were 64.7% G and 68.6% C for BsmI and FokI, respectively. Prevalence of these SNPs in the case population were: 43.3% GA, 43.3% GG and 13.7% AA BsmI and 49.0 % CC, 39.2% CT, 11.8% TT for FokI. The frequencies of alleles and genotypes showed no differences between patients with and without risk of hip fracture. The frequencies are agree to HapMap for European-Caucasian population. It was found no significant association between these SNPs and susceptibility to HF in the adult population of Andalusia(AU)

[Continuous femoral nerve block to control postoperative pain in outpatient orthopedic surgery]. / Bloqueo femoral continuo para control del dolor postoperatorio en cirugía ortopédica ambulatoria.

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.

Bloqueo femoral continuo para control del dolor postoperatorio en cirugía ortopédica ambulatoria / Continuous femoral nerve block to control postoperative pain in outpatient orthopedic surgery

OBJETIVOS: Investigar la eficacia, viabilidad y seguridad del bloqueo femoral continuo como técnica analgésica para cirugía ambulatoria de reconstrucción de ligamento cruzado anterior, ya que el dolor postoperatorio es una de las complicaciones más frecuentes en cirugía ortopédica ambulatoria. MATERIAL Y MÉTODOS: Estudio prospectivo simple. Pacientes estado físico ASA I-II, a los que se realizó tratamiento del dolor postoperatorio mediante bloqueo continuo del nervio femoral con bupivacaína 0,125%, a través de un dispositivo elastomérico dentro de un abordaje multimodal. El dolor postoperatorio fue evaluado mediante escala numérica y verbal desde el periodo postoperatorio inmediato hasta las primeras 48 horas. Se valoran los efectos secundarios y el grado de satisfacción de los pacientes. RESULTADOS: Se incluyeron 63 pacientes. El bloqueo continuo del nervio femoral fue eficaz (en las primeras 24 horas postoperatorias un porcentaje superior al 90% no presentó dolor o éste fue leve, sin necesidad de rescate en el 92% de los casos) y seguro como analgesia postoperatoria, con ausencia de efectos secundarios significativos. CONCLUSIÓN: El bloqueo continuo del nervio femoral con bupivacaína 0,125% administrada a través de sistemas elastoméricos es una opción de manejo del dolor postoperatorio eficaz y segura en cirugía ambulatoria de reconstrucción de ligamento cruzado anterior (AU)

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 singleblind 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 (AU)

[Systemic toxicity caused by local anesthetics after peripheral nerve blocks]. / Toxicidad sistémica por anestésicos locales tras bloqueos de nervios periféricos.

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.

Toxicidad sistémica por anestésicos locales tras bloqueos de nervios periféricos / Systemic toxicity caused by local anesthetics after peripheral nerve blocks

Existe en los últimos años un interés creciente de los anestesiólogos por los bloqueos nerviosos periféricos, lo cual puede conllevar un incremento en la frecuencia de aparición de complicaciones. Al mismo tiempo hubo grandes avances tecnológicos (neuroestimulación, ultrasonografía…) y se incorporaron anestésicos locales cada vez más seguros, sin embargo, no podemos obviar el riesgo de toxicidad sistémica asociado, que habitualmente se manifiesta con síntomas neurológicos que suelen preceder a los cardiovasculares. Presentamos dos casos de toxicidad sistémica utilizando mezclas de anestésicos locales durante la realización de bloqueos nerviosos periféricos en cirugía ambulatoria

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

[Brachial plexus block with levobupivacaine at the humeral canal: comparison of a small volume at high concentration with a large volume at low concentration]. / Bloqueo del plexo braquial a nivel humeral con levobupivacaína: estudio comparativo alta concentración/pequeiio volumen frente a baja concentraci6n/alto volumen.

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.

[Popliteal fossa sciatic nerve block for ambulatory hallux valgus surgery: comparison of lateral and posterior approaches]. / Bloqueo del nervio ciático en el hueco poplíteo para cirugía de hallux valgus en régimen ambulatorio: comparación de los abordajes lateral y posterior.

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.

Naúseas y vómitos postoperatorios en cirugía ambulatoria / Post-operative nause and vomiting in Ambulatory Surgery

Las náuseas y vómitos postoperatorios se incluyen entre las experiencias más desagradables que puede presentar un paciente, y constituyen uno de los motivos con mayor impacto negativo en la satisfacción global dentro del conjunto de la experiencia (..) (AU)

Post-operative nausea and vomiting are amongst the most disagreeable symptoms patients can experience and are one of the main negative reasons for patient's discontent with the surgical procedure. Despite the advances (..) (AU)