Improving short term instability for quantitative analyses with portable electronic noses.

One of the main problems when working with electronic noses is the lack of reproducibility or repeatability of the sensor response, so that, if this problem is not properly considered, electronic noses can be useless, especially for quantitative analyses. On the other hand, irreproducibility is increased with portable and low cost electronic noses where laboratory equipment like gas zero generators cannot be used. In this work, we study the reproducibility of two portable electronic noses, the PEN3 (commercial) and CAPINose (a proprietary design) by using synthetic wine samples. We show that in both cases short term instability associated to the sensors' response to the same sample and under the same conditions represents a major problem and we propose an internal normalization technique that, in both cases, reduces the variability of the sensors' response. Finally, we show that the normalization proposed seems to be more effective in the CAPINose case, reducing, for example, the variability associated to the TGS2602 sensor from 12.19% to 2.2%.

A compact and low cost electronic nose for aroma detection.

This article explains the development of a prototype of a portable and a very low-cost electronic nose based on an mbed microcontroller. Mbeds are a series of ARM microcontroller development boards designed for fast, flexible and rapid prototyping. The electronic nose is comprised of an mbed, an LCD display, two small pumps, two electro-valves and a sensor chamber with four TGS Figaro gas sensors. The performance of the electronic nose has been tested by measuring the ethanol content of wine synthetic matrices and special attention has been paid to the reproducibility and repeatability of the measurements taken on different days. Results show that the electronic nose with a neural network classifier is able to discriminate wine samples with 10, 12 and 14% V/V alcohol content with a classification error of less than 1%.

Induction of thrombosis of the abdominal aneurysm sac through the application of radiofrequency. An experimental study.

UNLABELLED: This is an experimental study of endovascular aortic surgery for evaluation of the effect of thrombosis induced in the aneurysmal sac using a radiofrequency method. PURPOSE: To determine the efficacy of the induction of thrombosis of the abdominal aneurysm sac as a prevention of endoleaks after endovascular treatment. MATERIALS AND METHODS: Six dogs underwent radiofrequency blood clotting of the aneurysm sac and where afterwards treated with stent-grafting. A comparison with a historical group of 4 dogs with an abdominal aneurysm treated with stent-grafting was used. Radiofrequency was applied to each sac for 1 minute at 127 mA ± 33 (mean ± SD) (tip temperature, 92°C ± 2). IVUS ultrasonography and histology studies were used for the evaluation of the method. RESULTS: The results show the efficacy of the radiofrequency method and its possible future inclusion as a standard clinical application. DISCUSSION AND CONCLUSIONS: Endovascular repair of abdominal aortic aneurysms is dependent on the complete exclusion of the aneurysm from the arterial circulation. Later growth of the aneurysm is originated from retrograde flow into the sac. This study demonstrates how the use of radiofrequency induced thrombosis in a canine model of aneurysm sac. Ultrasound IVUS enabled further control for assessment of blood coagulation after radiofrequency treatment. This approach may be considered a tool for future prevention of endoleaks, in clinical practice.

In vivo genetic engineering of murine pancreatic beta cells mediated by single-stranded adeno-associated viral vectors of serotypes 6, 8 and 9.

AIMS/HYPOTHESIS: The genetic engineering of pancreatic beta cells could be a powerful tool for examining the role of key genes in the cause and treatment of diabetes. Here we performed a comparative study of the ability of single-stranded (ss) adeno-associated viral vectors (AAV) of serotypes 6, 8 and 9 to transduce the pancreas in vivo. METHODS: AAV6, AAV8 and AAV9 vectors encoding marker genes were delivered to the pancreas via intraductal or systemic administration. Transduced cells were analysed by immunostaining. AAV9 vectors encoding hepatocyte growth factor (HGF) were delivered intraductally to a transgenic mouse model of type 1 diabetes and glycaemia was monitored. RESULTS: AAV6, AAV8 and AAV9 mediated efficient and long-term transduction of beta cells, with AAV6 and AAV8 showing the highest efficiency. However, alpha cells were poorly transduced. Acinar cells were transduced by the three serotypes tested and ductal cells only by AAV6. In addition, intraductal delivery resulted in higher AAV-mediated transduction of the pancreas than did systemic administration. As proof of concept, intraductal delivery of AAV9 vectors encoding for the beta cell anti-apoptotic and mitogenic HGF preserved beta cell mass, diminished lymphocytic infiltration of the islets and protected mice from autoimmune diabetes. CONCLUSIONS/INTERPRETATION: Intraductal administration of AAV6, AAV8 and AAV9 is an efficient way to genetically manipulate the pancreas in vivo. This technology may prove useful in the study of islet physiopathology and in assessment of new gene therapy approaches designed to regenerate beta cell mass during diabetes.

Bone remodeling, around an anatomical hip stem: a one year prospective study using DEXA. / Estudio prospectivo del remodelado óseo femoral alrededor de un vástago anatómico de cadera: un año de seguimiento densitométrico.

INTRODUCTION: The loss of bone mass, as a consequence of bone remodelling, in the proximal third of the femur, is a factor that contributes to the failure of hip prostheses in the medium to long term. This periprosthetic remodelling occurs mainly during the first 12 months after the operation. The aim is to evaluate the behaviour at one year of a new anatomical stem, the ANATO® stem (2015-Stryker®), which is a redesign of its predecessor (ABG-ii®-Stryker stem) by means of bone densitometry. METHOD: Prospective, controlled study in which the changes in bone mineral density (BMD) observed around the seven areas of Gruen in a group of 61 patients affected by primary coxarthrosis, in whom an ANATO® stem was implanted, are analysed densitometrically. The healthy hip was taken as the control group. The existence of differences in the remodelling pattern according to sex, age and body mass index (BMI) was compared. The follow-up was during the first year after the intervention. RESULTS: After one year of follow-up, decreases of bone mineral density in zone seven of -5.9% were observed, being this decrease statistically significant. No differences were found in the remodelling pattern according to age, sex and body mass index. CONCLUSION: The ANATO® stem allows an efficient transmission of loads from the stem to the proximal femur. Only in zone seven significant bone atrophy is observed. Differences in age, BMI and sex do not seem to influence the bone remodelling around this new stem.

Deficiency of CB2 cannabinoid receptor in mice improves insulin sensitivity but increases food intake and obesity with age.

AIMS/HYPOTHESIS: The endocannabinoid system has a key role in energy storage and metabolic disorders. The endocannabinoid receptor 2 (CB2R), which was first detected in immune cells, is present in the main peripheral organs responsible for metabolic control. During obesity, CB2R is involved in the development of adipose tissue inflammation and fatty liver. We examined the long-term effects of CB2R deficiency in glucose metabolism. METHODS: Mice deficient in CB2R (Cb2 ( -/- ) [also known as Cnr2]) were studied at different ages (2-12 months). Two-month-old Cb2 (-/-) and wild-type mice were treated with a selective CB2R antagonist or fed a high-fat diet. RESULTS: The lack of CB2R in Cb2 (-/-) mice led to greater increases in food intake and body weight with age than in Cb2 (+/+) mice. However, 12-month-old obese Cb2 (-/-) mice did not develop insulin resistance and showed enhanced insulin-stimulated glucose uptake in skeletal muscle. In agreement, adipose tissue hypertrophy was not associated with inflammation. Similarly, treatment of wild-type mice with CB2R antagonist resulted in improved insulin sensitivity. Moreover, when 2-month-old Cb2 (-/-) mice were fed a high-fat diet, reduced body weight gain and normal insulin sensitivity were observed. CONCLUSIONS/INTERPRETATION: These results indicate that the lack of CB2R-mediated responses protected mice from both age-related and diet-induced insulin resistance, suggesting that these receptors may be a potential therapeutic target in obesity and insulin resistance.

Comparison of the open versus the arthroscopic approach in the treatment of femoroacetabular shock. / Comparación del abordaje abierto frente al artroscópico en el tratamiento del choque femoroacetabular.

OBJECTIVE: To compare clinical and imaging results and complications between patients treated for femoroacetabular impingement who underwent either open surgery or an arthroscopic approach. METHODS: This retrospective study included patients who underwent femoroacetabular impingement surgical treatment between June 2009 and January 2018. Patients treated with open surgery were compared with those treated with arthroscopy. Patients were radiographically and clinically assessed by alpha angle, degree of arthritis, Harris Hip Score, hospital stay and complications, as well as progression to total hip arthroplasty. RESULTS: 57 patients with FAI were included; 27 (45.6%) underwent open surgery and 31 (54.4%) underwent arthroscopy. Statistically significant differences were observed in hospital stay, where the patients who underwent arthroscopic surgery showed better outcomes. There were no other statistically significant differences, the results were similar in both groups. CONCLUSIONS: Arthroscopy and open surgery treatments for femoroacetabular impingement provided comparable clinical and radiographic results. However, the latter surgery provides better results in surgery time, hospital stay and postoperative recovery.

[Clinical presentation, diagnosis, and long-term outcome of 29 patients with Wilson's disease]. / Presentación clínica, diagnóstico y evolución a largo plazo en 29 pacientes con enfermedad de Wilson.

OBJECTIVE: To analyze the clinical characteristics, treatment, and follow-up of a cohort of 29 patients with Wilson's disease (WD) within the region of Murcia. PATIENTS AND METHOD: We reviewed the medical records of 29 cases of WD (mean age, 20.3 +/- 13.4 years) diagnosed during the last 16 years. RESULTS: The most frequent reason for consultation was upon discovering a high transaminase level in almost half the patients, followed by tremors or dystonia in 17% of patients, respectively. A Kayser-Fleischer ring was observed in 17/29 (58.6%) of patients (100% of patients with pure neurological involvement and 35% of patients with pure clinical hepatic disease; p < 0.001). Blood copper levels not associated with ceruloplasmin as well as cupruria were notably superior in patients with neurological symptoms and in those with liver cirrhosis at the time of diagnosis. Patient clinical symptoms remained stable with D-penicillamine or trientine, or improved during the observation period, for 18 out of 29 patients (62%), while 11 out of 29 patients (38%) got worse. CONCLUSIONS: In our region patients with WD are diagnosed at a younger age, and in most cases for hepatic disease. Patients with neurological disease or liver cirrhosis had a high level of free copper not associated to ceruloplasmin and cupruria. The disease had a favorable evolution in all patients but those diagnosed with hepatic disease or advanced neurological disease.

[Giant hepatic hemangioma associated with Kasabach-Merrit syndrome]. / Hemangioma hepático gigante asociado a síndrome de Kasabach-Merrit.

Hepatic hemangioma is the most frequent liver's tumor. The majority are small, asymptomatic and have an excellent prognosis. Those larger than 5 cm can be associated to a consumptive coagulopathy called Kasabach-Merrit syndrome. We present a patient with a giant hepatic hemangioma with multiple hemangimatosis associated to Kasabach-Merrit syndrome.

Detection of particle motion using image processing with particular emphasis on rolling motion.

Image-processing has been used in granular systems for detecting particle positions and motion near optically accessible surfaces like sediment flow and bedload transport. We review the image-processing techniques used for single and multiple particles. To enhance reliability in particle recognition, tools like Canny edge and Hough transform are intensively used. We show exemplarily how they can be applied to detect not only particle positions but also rotatory motion. The different steps are described in detail and the algorithm is applied to different examples, which are discussed in view of the obtained accuracy.

[Distensibility changes in the thoracic aorta after stent-graft implantation. Experimental study in healthy and atheromatous animals]. / Alterações da elasticidade da aorta torácica após a implantação de endoprótese. Estudo experimental em animais saudáveis e ateromatosos.

UNLABELLED: The implantation into the arterial lumen of a stent-graft has repercussions in the metabolism of the different layers of the arterial wall. The authors conducted an experimental study with the purpose of evaluating the mechanical repercussions of an endoprosthesis into the arterial wall in normal and atheromatous animals. METHODS: The main group of animals was divided in two subgroups, the first with atheromatous induction and the second without treatment. Each subgroup was subdivided in two groups, a group with a simulated operation and the other with an endoprosthesis placed into the thoracic aorta. One half of the animals was evaluated at one month and the remaining at three months, with removal of the thoracic aorta. The animals were analyzed with electronics methods to assess the elasticity of the thoracic aorta. RESULTS: The study found that ePTFE endoprosthetic grafts placed in atherosclerotic animals increased the intimal hyperplasia and wall alterations compared with the control group and the group with implantation in normal animals but this group showed less alterations of atherosclerosis than the group without endoprosthetic grafts. DISCUSSION: Different factors may cause reactive changes in the arterial wall leading to atheromatosis in arteries with endoprosthesis implantation, but the lipid factor in induction of atheromatosis increases the possibility of alteration of the different layers of the arterial wall. The endoprosthesis implantation is an important factor for the development of the mechanical changes in the arterial wall.

[Influence of preoperative bone mass density in periprosthetic bone remodeling after implantation of ABG-II prosthesis: A 10-year follow-up]. / Influencia de la masa ósea preoperatoria en la remodelación femoral periprotésica tras la implantación de una prótesis ABG-II: resultados tras 10 años de seguimiento.

INTRODUCTION: Preoperative bone mass index has shown to be an important factor in peri-prosthetic bone remodelling in short follow-up studies. MATERIAL AND METHODS: Bone density scans (DXA) were used to perform a 10-year follow-up study of 39 patients with a unilateral, uncemented hip replacement. Bone mass index measurements were made at 6 months, one year, 3 years, 5 years, and 10 years after surgery. Pearson coefficient was used to quantify correlations between preoperative bone mass density (BMD) and peri-prosthetic BMD in the 7 Gruen zones at 6 months, one year, 3 years, 5 years, and 10 years. RESULTS: Pre-operative BMD was a good predictor of peri-prosthetic BMD one year after surgery in zones 1, 2, 4, 5 and 6 (Pearson index from 0.61 to 0.75). Three years after surgery it has good predictive power in zones 1, 4 and 5 (0.71-0.61), although in zones 3 and 7 low correlation was observed one year after surgery (0.51 and 0.57, respectively). At the end of the follow-up low correlation was observed in the 7 Gruen zones. Sex and BMI were found to not have a statistically significant influence on peri-prosthetic bone remodelling. CONCLUSION: Although preoperative BMD seems to be an important factor in peri-prosthetic remodelling one year after hip replacement, it loses its predictive power progressively, until not being a major factor in peri-prosthetic remodelling ten years after surgery.

Functional reorganization of neural auditory maps by differential learning.

A new perspective on neural mechanisms of learning is emerging from studies showing that some sensory maps in mature brains can be reorganized in response to conditioned stimuli. Autoradiography with [14C] 2-deoxy-2-fluoro-D-glucose was used to examine changes in the functional tonotopic organization of the rat inferior colliculus during differential Pavlovian conditioning. Metabolic comparisons of adjacent tonotopic maps were made within the same inferior colliculus. They showed that tonotopic maps were enhanced during differential learning of tones associated with an arousing stimulus. The findings support a concept of sensory learning that postulates a functional reorganization of sensory maps in adult brains.

Functional mapping of the rat brain during drinking behavior: a fluorodeoxyglucose study.

Autoradiographic techniques using the radiolabeled glucose analog [14C]2-fluoro-2-deoxy-D-glucose (FDG) were used to map the functional activity in the CNS during drinking behavior. Rats were trained to drink water during a 1-h session each day. Half of the rats were injected with FDG and allowed to drink, while the other half were satiated prior to FDG injection. Uptake of FDG for drinking and control groups of rats was quantified in 60 brain structures from frontal cortex to cervical spinal cord. The largest percent increase in activity (96%) during drinking was in the lateral hypothalamus. Limbic structures with significant metabolic increases included the lateral septum (48%), lateral habenula (44%), and nucleus accumbens (32%). Thalamic nuclei activated included intralaminar (60%), zona incerta (51%), ventroposteromedial (50%), anterior ventral (47%), and dorsal medial (40%). Other structures with increases were the caudal caudate nucleus (53%) and the spinal trigeminal nucleus (45%). The findings were interpreted in light of related metabolic mapping studies of the effects of orofacial stimulation, dehydration, ingestion, arousal, and reward. It was concluded that this FDG study revealed primarily the involvement of structures linked to rewarding and arousal components of motivated drinking behavior, as well as sensorimotor correlates of the orofacial stimulation. The findings provide the first comprehensive functional map of brain systems related to drinking behavior in adult animals.

[Tetraplegia in the immediate postoperative period of stapedectomy]. / Tetraplejía en el postoperatorio inmediato de una estapedectomía.

Management of the cervical spine in orotracheal intubation for general anesthesia is an important aspect of daily practice in anesthesiology. Also important are the requirements, techniques and consequences of patient position during surgery. We report a case of tetraplegia during the early postoperative period after stapedectomy for otosclerosis. After surgery, the spontaneously breathing patient was transferred to the recovery room, where a clinical picture of anesthesia and paralysis of all four limbs was evident. We ordered an emergency magnetic resonance image of the cervical spine, which revealed a massive acutely herniated disk at C6-C7 with signs of ischemia or necrosis of the medulla at the same level. After eight months, the patient was still paraplegic and lacked sensation in the lower limbs. Sensation and motor function in the upper limbs was nearly normal. We review the etiopathogenetic mechanisms that might be responsible for this clinical profile.

IGF-I mediates regeneration of endocrine pancreas by increasing beta cell replication through cell cycle protein modulation in mice.

AIMS/HYPOTHESIS: Recovery from diabetes requires restoration of beta cell mass. Igf1 expression in beta cells of transgenic mice regenerates the endocrine pancreas during type 1 diabetes. However, the IGF-I-mediated mechanism(s) restoring beta cell mass are not fully understood. Here, we examined the contribution of pre-existing beta cell proliferation and transdifferentiation of progenitor cells from bone marrow in IGF-I-induced islet regeneration. METHODS: Streptozotocin (STZ)-treated Igf1-expressing transgenic mice transplanted with green fluorescent protein (GFP)-expressing bone marrow cells were used. Bone marrow cell transdifferentiation and beta cell replication were measured by GFP/insulin and by the antigen identified by monoclonal antibody Ki67/insulin immunostaining of pancreatic sections respectively. Key cell cycle proteins were measured by western blot, quantitative RT-PCR and immunohistochemistry. RESULTS: Despite elevated IGF-I production, recruitment and differentiation of bone marrow cells to beta cells was not increased either in healthy or STZ-treated transgenic mice. In contrast, after STZ treatment, IGF-I overproduction decreased beta cell apoptosis and increased beta cell replication by modulating key cell cycle proteins. Decreased nuclear levels of cyclin-dependent kinase inhibitor 1B (p27) and increased nuclear localisation of cyclin-dependent kinase (CDK)-4 were consistent with increased beta cell proliferation. However, islet expression of cyclin D1 increased only after STZ treatment. In contrast, higher levels of cyclin-dependent kinase inhibitor 1A (p21) were detected in islets from non-STZ-treated transgenic mice. CONCLUSIONS/INTERPRETATION: These findings indicate that IGF-I modulates cell cycle proteins and increases replication of pre-existing beta cells after damage. Therefore, our study suggests that local production of IGF-I may be a safe approach to regenerate endocrine pancreas to reverse diabetes.

Overexpression of Il6 leads to hyperinsulinaemia, liver inflammation and reduced body weight in mice.

AIMS/HYPOTHESIS: IL-6 is released by the adipose tissue and increased circulating levels in obesity are associated with hyperinsulinaemia and insulin resistance. Short-term experiments suggest that increased IL-6 release by the skeletal muscle following exercise may improve insulin sensitivity. METHODS: In order to examine the effect of chronically elevated IL-6 levels, we overexpressed Il6 in skeletal muscle in mice using an electro-transfer procedure. RESULTS: Circulating IL-6 levels were increased and the animals rapidly lost both weight and body fat, but food intake was unchanged, which is consistent with the finding that IL-6 increased energy expenditure. Insulin levels were inappropriately elevated and combined with hypoglycaemia in spite of reduced 2-deoxy-D: -glucose uptake by skeletal muscle. Insulin-stimulated glucose uptake by skeletal muscles ex vivo was reduced, probably due to the decreased amounts of glucose transporter (GLUT)-4. Beta cell insulin content was increased, while apparent beta cell mass was unchanged. Circulating serum amyloid A cluster levels were increased tenfold due to a pronounced proinflammatory state in the liver with infiltration of inflammatory cells. However, no liver steatosis was found, which may be accounted for by concomitant AMP kinase activation. CONCLUSIONS/INTERPRETATION: Chronically elevated IL-6 levels lead to inappropriate hyperinsulinaemia, reduced body weight, impaired insulin-stimulated glucose uptake by the skeletal muscles and marked inflammation in the liver. Thus, the pleiotrophic effects of chronically elevated IL-6 levels preclude any obvious usefulness in treating obesity or its associated metabolic complications in man, despite the fact that weight reduction may be expected.