Thermal response following light delivery used to improve deep brain stimulation surgery

Titre de l'écran-titre (visionné le 19 juin 2023)Une approche neurochirurgicale impliquant la stimulation intracérébrale profonde peut être utilisée afin d'atténuer les symptômes moteurs de la maladie de Parkinson lorsque l'efficacité des traitements pharmacologiques diminuent. La précision dans le placement des électrodes de stimulation à l'intérieur du cerveau est critique et les bienfaits cliniques qui découlent de cette chirurgie dépendent directement du positionnement des électrodes. Par conséquent, il est essentiel de mettre en œuvre des méthodes qui pourraient conduire à une meilleure précision du placement des électrodes lors de la chirurgie. Certaines méthodes, telles que l'enregistrement par microélectrode (MER) combiné à l'imagerie par résonnance magnétique (IRM), sont actuellement utilisées par les neurochirurgiens afin d'améliorer la précision du placement des électrodes. Le MER permet d'enregistrer les patrons de décharges d'un seul neurone afin d'identifier la cible et de confirmer l'emplacement des électrodes dans le cerveau. Même si le MER améliore le positionnement des électrodes, il a été démontré que cette méthode augmente le risque de saignement, la durée de l'opération ainsi que la quantité d'anesthésie administrée. Des électrodes contenant une sonde optique guidées grâce à la lumière pourraient être grandement utiles afin d'augmenter la précision durant la chirurgie. La spectroscopie de réflectance diffuse (DRS) est l'une des méthodes qui peut être efficace à cet égard. Cependant, un inconvénient possible de cette méthode est l'endommagement potentiel des tissus qui pourrait être causé par le transfert d'énergie et donc de chaleur vers les tissus. L'objectif général de cette étude est d'évaluer si l'utilisation de techniques de guidage optique utilisant la lumière serait sécuritaire afin d'améliorer la précision des chirurgies DBS. Brièvement, le logiciel PyTissueoptics a été utilisé afin de simuler le transport de la lumière dans le tissu cérébral et de trouver le volume quadratique moyen (RMS) d'absorption d'énergie. Avec ces informations en main, le tissu cérébral a été modélisé dans COMSOL afin de simuler la diffusion de la chaleur et de trouver la fraction de dommage. Dans l'ensemble, nos données suggèrent que l'augmentation de la température induite par l'utilisation de la lumière nécessaire au guidage optique est négligeable et ne serait pas suffisante afin d'induire un dommage significatif au parenchyme cérébral.Deep brain stimulation surgery is commonly used to alleviate motor symptoms of Parkinson's disease (PD) in its late stages when pharmaceutical treatments become less effective. Precision in accurate placement of electrodes in deep brain structures is extremely important in the clinical outcome of the surgery. Therefore, it is essential to implement methods that can provide better accuracy for electrode placement during surgery. Some methods, such as microelectrode recording (MER), following pre-operative MRI trajectory planning, are currently used by neurosurgeons to gain precision during the surgery. MER records single neuron firing patterns in order to identify the target structure and confirm the location of the electrodes in the brain. Even though MER contributes to improved precision in electrode placement, it has been shown to increase bleeding risk, operation time, and either local or general anesthesia. Light-guided probes could be used to gain more precision during surgery. Diffuse reflectance spectroscopy (DRS) is one of the light-guided methods that can be effective in this regard. However, one possible drawback of this method is the potential tissue damage that could be caused by heat transferred to the tissue. The overarching goal of this study is to assess the safety of using light-guided techniques such as DRS, during DBS surgery. To reach this goal, computer simulations have been done with PyTissueoptics to simulate light transport in the brain tissue and find the root mean square (RMS) volume of energy absorbance and heat-up temperature. This information has then been used into COMSOL to simulate heat diffusion in brain tissue. By doing so, we were able to assess the temperature rise, in conjunction with possible fraction of damage that could occur in brain tissue. Using these simulations, we show that light needed for DRS guided surgery induces minimal temperature rise and non-significant damage to brain tissue

Comparison of the Effect of Misoprostol and Chewing Gum on Intestinal Movements after Cesarean Delivery

Cesarean is one of the major surgeries after which mother will need to be hospitalized for a long period of time. One of the leading causes of the increase in the duration of hospitalization of such patients is the surgeons’ projections about the development of ileus and defecation. Given the previous studies, misoprostol can increase bowel movements. Moreover, gum-chewing has been recommended as a cheap and available technique for accelerating the resumption of normal Intestinal Movements. The present study is a singleblind randomized clinical trial which has been done on 324 women over 18 years of age with singleton pregnancy who had visited Taleghani Hospital in Arak and was elective cesarean section candidates. The surgery and anesthesia techniques were similar for all patients. These patients were randomized into three groups of 108, namely control, misoprostol, and gum-chewing groups. The patients in these three groups were compared with one another in terms of normal bowel sound, gas passage, defecation and discharge. The results have shown the mean age of a total of 324 patients has been 26.66 years. The results suggest that the time of hearing the first normal bowel sound, the first gas passage, and defecation have been shorter in the misoprostol group, gum-chewing group and control group, respectively. The difference observed between the three groups has been significant at a 0.05 significance level. Furthermore, no significant difference was observed between the patients in the misoprostol and gum-chewing groups and the patients in the control group while reviewing the time of discharge of these patients. The findings have been indicative of the positive effects of the misoprostol and gumchewing techniques on the intestinal function of patients and mothers’ breastfeeding. Also, it has been observed that using misoprostol can be more effective than chewing gum

-Terpineol attenuates morphine-induced physical dependence and tolerance in mice: role of nitric oxide

Objective(s):Dependence and tolerance to opioid analgesics are major problems limiting their clinical application. a-Terpineol is a monoterpenoid alcohol with neuroprotective effects which is found in several medicinal plants such as Myrtus communis, Laurus nobilis, and Stachys byzantina. It has been shown that some of these medicinal plants such as S. byzantina attenuate dependence and tolerance to morphine. Since a-terpineol is one of the bioactive phytochemical constituent of these medicinal plants, the present study was conducted to investigate the effects of a-terpineol on morphine-induced dependence and tolerance in mice. Materials and Methods: The mice were rendered dependent or tolerant to morphine by a 3-day administration schedule. The hot-plate test and naloxone-induced withdrawal syndrome were used to evaluate tolerance and dependence on morphine, respectively. To investigate a possible role for nitric oxide (NO) in the protective effect of a-terpineol, the NO synthase inhibitor, L-N(G)-nitroarginine methyl ester (L-NAME) and NO precursor, L-arginine, were used. Results: Administration of a-terpineol (5, 10, and 20 mg/kg, IP) significantly decreased the number of jumps in morphine dependent animals. Moreover, a-terpineol (20 and 40 mg/kg, IP) attenuated tolerance to the analgesic effect of morphine. The inhibitory effects of a-terpineol on morphine-induced dependence and tolerance were enhanced by pretreatment with L-NAME (10 mg/kg, IP). However, L-arginine (300 mg/kg, IP) antagonized the protective effects of a-terpineol on dependence and tolerance to morphine. Conclusion: These findings indicate that a-terpineol prevents the development of dependence and tolerance to morphine probably through the influence on NO production

ZnO-SrAl2O4:Eu Nanocomposite-Based Optical Sensors for Luminescence Thermometry

Conventional thermometers fail to operate in a variety of medical procedures due to the harsh and sensitive environments required for such applications, and therefore, the development of optical fiber thermometers has gained significant attention. In this study, a ZnO-SrAl2O4:Eu (ZnO-SAO:Eu) nanocomposite has been synthesized by using a CO2 laser, which showed enhanced optical properties and a dynamic range in comparison with the crystalline ones. XRD, EDAX, SEM, and PL spectroscopy investigated the crystalline and optical properties of precursors, and the final nanostructure, and the findings were in agreement with references. Further analysis of the PL spectra in a 0-100 degrees C range suggests that the optical properties of the ZnO-SAO:Eu nanocomposite show a linear behavior toward temperature alterations. Considering this inter-relation and measuring the decay time for various frequencies helped us calibrate the temperature based on phase angle shift alterations. The curve obtained at 30 Hz frequency exhibits the highest linearity and accuracy (0.33%) due to its relatively high phase shift (60 degrees C) in the studied temperature range. The fabricated sensor exhibited great sensitivity and repeatability while maintaining an unprecedented structure. Finally, the thermometer's applicability for future industries was tested by measuring the interior temperature of a dead muscle tissue as it was being heated by a diode laser and it was accompanied by remarkable results. This achievement could make this device a promising addition to the drug delivery science and industry as it could aid the study and optimization of medications that increase the targeted tissues temperature and therefore can be employed in treating tumors that are formed in organic tissues

Comprehensive assessment of nutritional status and nutritional-related complications in newly diagnosed esophageal cancer patients: a cross-sectional study

Background & aims: Malnutrition is prevalent in upper gastrointestinal cancer patients. The purpose of this study was a comprehensive assessment of nutritional status in newly diagnosed patients with esophageal cancer. Methods: Newly diagnosed esophageal cancer patients were referred to a chemo-radiation referral center in Mashhad, Iran, between February 2017 to February 2019. Anthropometric indices, a Patient-Generated Subjective Global Assessment (PG-SGA) tool, body composition, dietary intake, nutritional-related complications, and laboratory tests were assessed. Results: One hundred and eighty-nine patients with a mean age of 67.1 ± 12 and a male to female ratio of 98 to 91 were included. Ninety-seven (51.3%) of patients had experienced significant weight loss and 56 (29.6%) were underweight at diagnosis. According to PG-SGA, 179 (94.7%) needed nutritional interventions. Reduced muscle mass and low handgrip strength were observed in 70 (39.4%) and 26 (14.4%) of patients, respectively. Inadequate intakes of energy (less than 24 kcal/kg/day) and protein (less than 1.2 g/kg/day) were found in 146 (77.8%) and 171 (91%) patients, respectively. The mean total daily energy and protein intakes of subjects were 943.8 ± 540 kcal/day, and 30.6 ± 21 g/day, respectively. The most common nutritional-related complications were as follows: dysphagia (84.8%), anorexia (31.6%), constipation (62.1%), esophageal pain (48.4%), and dyspepsia (41.1%). Conclusion: Our study demonstrated a high prevalence of malnutrition in newly diagnosed esophageal cancer patients. This fact demonstrates the importance of early screening of nutritional status via PG-SGA tool, clinical evaluation, dietary intake evaluations, and laboratory tests, based on which effective nutritional interventions and Symptoms management may be introduced in these patients