An in vitro comparison of subjective image quality of panoramic views acquired via 2D or 3D imaging

Objectives

The objective of this study is to compare subjective image quality and diagnostic validity of cone-beam CT (CBCT) panoramic reformatting with digital panoramic radiographs.

Materials and methods

Four dry human skulls and two formalin-fixed human heads were scanned using nine different CBCTs, one multi-slice CT (MSCT) and one standard digital panoramic device. Panoramic views were generated from CBCTs in four slice thicknesses. Seven observers scored image quality and visibility of 14 anatomical structures. Four observers repeated the observation after 4 weeks.

Results

Digital panoramic radiographs showed significantly better visualization of anatomical structures except for the condyle. Statistical analysis of image quality showed that the 3D imaging modalities (CBCTs and MSCT) were 7.3 times more likely to receive poor scores than the 2D modality. Yet, image quality from NewTom VGi® and 3D Accuitomo 170® was almost equivalent to that of digital panoramic radiographs with respective odds ratio estimates of 1.2 and 1.6 at 95% Wald confidence limits. A substantial overall agreement amongst observers was found. Intra-observer agreement was moderate to substantial.

Conclusions

While 2D-panoramic images are significantly better for subjective diagnosis, 2/3 of the 3D-reformatted panoramic images are moderate or good for diagnostic purposes.

Clinical relevance

Panoramic reformattings from particular CBCTs are comparable to digital panoramic images concerning the overall image quality and visualization of anatomical structures. This clinically implies that a 3D-derived panoramic view can be generated for diagnosis with a recommended 20-mm slice thickness, if CBCT data is a priori available for other purposes.     

Kinematic patterns for hindlimb obstacle avoidance during sheep locomotion

ABSTRACT

Functional recovery following general nerve reconstruction is often associated with poor results. Comparing to rat and mice experimental studies, there are much fewer investigations on nerve regeneration and repair in the sheep, and there are no studies on this subject using gait analysis in the sheep model as an assessment tool. Additionally, this is the first study evaluating obstacle negotiation and the compensatory strategies that take place at each joint in response to the obstacle during locomotion in the sheep model. This study aims to get kinematic data to serve as a template for an objective assessment of the ankle joint motion in future studies of common peroneal nerve (CP) injury and repair in the ovine model. Our results show that a moderately high obstacle set to 10% of the sheep’s hindlimb length was associated to several spatial and temporal strategies in order to increase hoof height during obstacle negotiating. Sheep efficiently cleared an obstacle by increasing knee, ankle and metatarsophalangeal flexion during swing, whereas the hip joint is not affected. This study establishes the bounds of normal motion in the neurologically intact hindlimb when approached and cleared an obstacle and provides baseline data for further studies of peripheral nerve research in the ovine model.     

Dibucaine in Ionic-Gradient Liposomes: Biophysical,Toxicological, and Activity Characterization

Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of DBC.     

Sustained Release from Ionic-Gradient Liposomes Significantly Decreases ETIDOCAINE Cytotoxicity

Purpose

Etidocaine (EDC) is a long lasting local anesthetic, which alleged toxicity has restricted its clinical use. Liposomes can prolong the analgesia time and reduce the toxicity of local anesthetics. Ionic gradient liposomes (IGL) have been proposed to increase the upload and prolong the drug release, from liposomes.

Methods

First, a HPLC method for EDC quantification was validated. Then, large unilamellar vesicles composed of hydrogenated soy phosphatidylcholine:cholesterol with 250 mM (NH₄)₂SO₄ - inside gradient - were prepared for the encapsulation of 0.5% EDC. Dynamic light scattering, nanotracking analysis, transmission electron microscopy and electron paramagnetic resonance were used to characterize: nanoparticles size, polydispersity, zeta potential, concentration, morphology and membrane fluidity. Release kinetics and in vitro cytotoxicity tests were also performed.

Results

IGL_EDC showed average diameters of 172.3?±?2.6 nm, low PDI (0.12?±?0.01), mean particle concentration of 6.3?±?0.5?×?10¹²/mL and negative zeta values (?10.2?±?0.4 mV); parameters that remain stable during storage at 4°C. The formulation, with 40% encapsulation efficiency, induced the sustained release of EDC (ca. 24 h), while reducing its toxicity to human fibroblasts.

Conclusion

A novel formulation is proposed for etidocaine that promotes sustained release and reduces its cytotoxicity. IGL_EDC can come to be a tool to reintroduce etidocaine in clinical use.

     

Video-Assisted Surgery Implementation in the Public Health System of a Developing Country

Background

Over the last two decades, video-assisted surgery has become the preferential access route for many procedures. Despite cholecystectomy being the laparoscopic procedure most frequently performed in Brazilian public hospitals from 2008 to 2012, the lack of population-based studies led us to conduct a survey on the prevalence of video-assisted surgery in the treatment of patients using the Sistema Único de Saúde (SUS) (Unified Health System), which is the universal, free, and public healthcare system of Brazil.

Methods

By analyzing the DATASUS (national public health registry database), the prevalence of laparoscopic cholecystectomy and open cholecystectomy (OC) was calculated in the period from January to December in 2008, 2010 and 2012, taking into consideration their geographic distribution throughout Brazil.

Results

At the end of the study period, an increase in the number of laparoscopic cholecystectomies was observed, with a variation of 125.7 %. However, OC was more prevalent despite an increase in the use of video-assisted surgery over the 5-year study period, increasing from 12 to 25 % in 2012.

Conclusions

In spite of a trend toward increased use of video-assisted surgery for treating SUS patients during the period under study, the data from 2012 are still far from being ideal. For this population, OC via laparotomy is still the most prevalent option in all regions. This information must encourage the Brazilian surgical societies to push for an improvement in the supply of the treatment provided by the public health system.     

Validation of an HPLC Analytical Method for the Quantitative/Qualitative Determination of Fluticasone Propionate in Inhalation Particles on Several Matrices

Fluticasone propionate is a highly potent corticosteroid used to treat asthma and allergic rhinitis. It is a very effective drug, but has the inconvenient factor of being insoluble in water. Cyclodextrins were used to improve this limitation because of their ability to form inclusion complexes with guest drug molecules as well as increase the stability and bioavailability of the drugs. A rapid and simple HPLC method was developed to detect and quantify fluticasone propionate in inhalation particles on several matrices. Liquid chromatography with a UV detector at a wavelength of 236 nm, using a C18 column, was employed in this study. Isocratic elution was employed using a mixture of acetonitrile and water (60:40, v/v). The analytical method validation was performed in accordance with ICH guidelines, which included selectivity, range, linearity, accuracy, detection limit, quantitation limit, precision, robustness, and stability of solutions. This method showed to be selective and specific. Acceptable assay precision and accuracy (100 ± 5.0%) were obtained at 50– 150% of the analytical concentration of fluticasone propionate at the target concentration of 0.060 mg/mL, and good linearity (0.9958) was achieved over a range of 0.03 to 0.09 mg/mL for fluticasone propionate. The proposed HPLC method proved to be reliable. The validation and application of this method can be adopted for determining the fluticasone propionate in: assays, impingers and impactors, diffusion cells, dissolutions, and other tests. In addition, this method can be adapted and used in the pharmaceutical industry for routine analysis.     

No evidence of de novo amyloidosis in recipients of domino liver transplantation: 12 to 40 (mean 24) month follow-up.

Domino liver transplantation (DLT) has been performed for selected recipients at several centers, but de novo amyloidosis in recipients of livers from patients with familial amyloid polyneuropathy (FAP) remains a serious concern. AIM: To evaluate the occurrence of de novo amyloidosis in recipients of DLT. PATIENTS AND METHODS: Seven recipients of FAP livers were followed for clinical and electroneuromyographic signs of FAP and also for de novo amyloid deposition in the gut. RESULTS: No signs and symptoms of de novo FAP nor any evidence of amyloid deposits in the gut were observed in recipients of DLT after a mean follow-up of 24 [12-40] months. CONCLUSIONS: Signs and symptoms of FAP do not occur early in recipients of DLT. These livers could therefore be offered to patients suitable for conventional LT, particularly older subjects in whom the event of de novo amyloidosis would seem improbable.     

The man who feels two hearts: the different pathways of interoception

Recent advances in neuroscience have provided new insights into the understanding of heart–brain interaction and communication. Cardiac information to the brain relies on two pathways, terminating in the insular cortex (IC) and anterior cingulate cortex (ACC), along with the somatosensory cortex (S1-S2). Interoception relying on these neuroanatomical pathways has been shown to modulate social cognition. We report the case study of C.S., a patient with an ‘external heart’ (an extracorporeal left-univentricular cardiac assist device, LVAD). The patient was assessed with neural/behavioral measures of cardiac interoception complemented by neuropsychological and social cognition measures. The patient’s performance on the interoception task (heartbeat detection) seemed to be guided by signals from the artificial LVAD, which provides a somatosensory beat rather than by his endogenous heart. Cortical activity (HEP, heartbeat-evoked potential) was found decreased in comparison with normal volunteers, particularly during interoceptive states. The patient accurately performed several cognitive tasks, except for interoception-related social cognition domains (empathy, theory of mind and decision making). This evidence suggests an imbalance in the patient’s cardiac interoceptive pathways that enhances sensation driven by the artificial pump over that from the cardiac vagal-IC/ACC pathway. A patient with two hearts, one endogenous and one artificial, presents a unique opportunity to explore models of interoception and heart–brain interaction.