RESUMO
This study aimed to investigate the effect of glycerol as an Optical Clearing Agent on the temperature profile of the skin during HyperThermic Laser Lipolysis using computer simulation. In this study, a three-layer model of the skin was used to simulate HyperThermic Laser Lipolysis. The Monte Carlo MCML code was used to investigate the propagation of laser photons inside skin tissue. The energy absorbed from photons is used as a heat source to determine the increase in temperature and assess thermal damage in the layers of the skin. The finite element method in COMSOL software was used for calculation. The simulation of single-pulse radiation exposure with and without applying glycerol to the skin model was investigated to assess the impact of glycerol. Glycerol decreases the temperature and thermal damage to the epidermis layer while increasing the temperature of the fat layer. Moreover, the presence of glycerol increases the depth of fat cell destruction. Glycerol, as a supplement, significantly improves the efficacy of HyperThermic Laser Lipolysis.
Assuntos
Glicerol , Lipólise , Simulação por Computador , Lasers , PeleRESUMO
Multimodal image registration is a key for many clinical image-guided interventions. However, it is a challenging task because of complicated and unknown relationships between different modalities. Currently, deep supervised learning is the state-of-theart method at which the registration is conducted in end-to-end manner and one-shot. Therefore, a huge ground-truth data is required to improve the results of deep neural networks for registration. Moreover, supervised methods may yield models that bias towards annotated structures. Here, to deal with above challenges, an alternative approach is using unsupervised learning models. In this study, we have designed a novel deep unsupervised Convolutional Neural Network (CNN)-based model based on computer tomography/magnetic resonance (CT/MR) co-registration of brain images in an affine manner. For this purpose, we created a dataset consisting of 1100 pairs of CT/MR slices from the brain of 110 neuropsychic patients with/without tumor. At the next step, 12 landmarks were selected by a well-experienced radiologist and annotated on each slice resulting in the computation of series of metrics evaluation, target registration error (TRE), Dice similarity, Hausdorff, and Jaccard coefficients. The proposed method could register the multimodal images with TRE 9.89, Dice similarity 0.79, Hausdorff 7.15, and Jaccard 0.75 that are appreciable for clinical applications. Moreover, the approach registered the images in an acceptable time 203 ms and can be appreciable for clinical usage due to the short registration time and high accuracy. Here, the results illustrated that our proposed method achieved competitive performance against other related approaches from both reasonable computation time and the metrics evaluation.
Assuntos
Aprendizado Profundo , Humanos , Processamento de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagemRESUMO
BACKGROUND: Distal femur fracture is considered one of the most common fractures due to high-energy traumas such as car accidents or low-energy traumas such as osteoporosis. Locking plates are orthopedic implants used for stabilized femur fracture. Thus, designing a bone plate fitted exactly with the patient's bone and correctly fixing bone segments are required for better fracture healing. OBJECTIVES: This study aims to design a bone plate based on anthropometric characteristics of patients' femurs and compare performing custom-designed bone plates (CDBP) with the locking compression plate (LCP) by finite element method. MATERIALS AND METHODS: In this analytical study, a 3D model of four patients' femur and CDBP were firstly designed in MIMICS 19.0 based on the patient's femur anatomy. After designing the bone plate, the CDBPs and LCP were fixed on the bone and analyzed by finite element method (FEM) in ANSYS, and stress and strain of bone plates were also compared. RESULTS: The maximum principal stress for all 3D models of patients' fracture femur by CDBPs was stabilized better than LCP with a decrease by 39.79, 12.54, 9.49, and 20.29% in 4 models, respectively. Also, in all models, the strain of CDBPs is less than LCP. Among the different thicknesses considered, the bone plate with 5 mm thickness showed better stress and strain distribution than other thicknesses. CONCLUSION: Customized bone plate designed based on patient's femur anatomical morphology shows better bone-matching plate, resulting in increasing the quality of the fracture healing and fails to any need for additional shaping. TRIAL REGISTRATION NUMBER: Design and analysis of an implant were investigated in this study. There was no intervention in the diagnosis and treatment of patients and the study was not a clinical trial.
Assuntos
Placas Ósseas , Fraturas Femorais Distais , Fixação Interna de Fraturas , Humanos , Fenômenos Biomecânicos , Fraturas Femorais Distais/cirurgia , Fêmur/anatomia & histologia , Fixação Interna de Fraturas/instrumentação , Desenho de Equipamento , Análise de Elementos Finitos , Modelos AnatômicosRESUMO
BACKGROUND: Weight loss is the cornerstone of NAFLD management, but weight maintenance is difficult. Some studies have suggested that n-3 polyunsaturated fatty acid (n-3 PUFA) might have beneficial effects in NAFLD. We aim to compare the effects of a low-energy diet with n-3 PUFA supplementation on liver enzymes, body composition, and cardiometabolic risk factors in NAFLD. MATERIALS AND METHODS: The study was a randomized controlled trial conducted in Urmia in Iran from October 2016 to May 2017. One hundred and fourteen eligible patients were randomly assigned to one of the three following groups: low-energy diet group, n-3 PUFA supplementation (fish oil) group (1500 mg/d), or control group for 12 weeks. Liver enzymes, lipid profile, insulin resistance, and body composition were assessed before and after the intervention. RESULTS: One hundred and four patients completed the study. All groups lost weight, but the reductions were greater in the diet group (-2.97 ± 2.79 kg, P = 0.001). The diet group had significant decreases in fat mass compared to other groups. Insulin resistance, total cholesterol, and low-density lipoprotein cholesterol significantly decreased only in the diet group, and patients who lost weight ≥4% showed significantly larger decreases in serum liver enzymes. N-3 PUFA had no beneficial effects on the study outcomes. CONCLUSION: We found that 1500 mg/d n-3 PUFA supplied for 12 weeks, in contrast to 3.40 ± 2.98% weight loss, does not improve liver enzymes, body composition, and cardiometabolic risk factors in NAFLD patients.
RESUMO
Branched chain amino acids (BCAA), with vitamin B6 have been reported to improve fat metabolism and muscle synthesis. We hypothesized that supplementation with BCAA and vitamin B6 would result in more weight loss and improve body composition and blood markers related to cardiovascular diseases. Our aim was to determine whether the mentioned supplementation would affect weight loss, body composition, and cardiovascular risk factors during weight loss intervention. To this end, we performed a placebo-controlled randomized clinical trial in 42 overweight and obese women (BMI = 25-34.9 kg/m2). Taking a four-week moderate deficit calorie diet (-500 kcal/day), participants were randomized to receive BCAA (6 g/day) with vitamin B6 (40 mg/day) or placebo. Body composition variables measured with the use of bioelectrical impedance analysis, homeostatic model assessment, and plasma insulin, Low density lipoprotein, High density lipoprotein, Total Cholesterol, Triglyceride, and fasting blood sugar were measured. The result indicated that, weight loss was not significantly affected by BCAA and vitamin B6 supplementation (-2.43 ± 1.02 kg) or placebo (-1.64 ± 1.48 kg). However, significant time × treatment interactions in waist to hip ratio (P = 0.005), left leg lean (P = 0.004) and right leg lean (P = 0.023) were observed. Overall, supplementation with BCAA and vitamin B6 could preserve legs lean and also attenuated waist to hip ratio.
Assuntos
Aminoácidos de Cadeia Ramificada , Vitamina B 6/metabolismo , Redução de Peso , Feminino , Humanos , Obesidade , Sobrepeso , Vitamina B 6/químicaRESUMO
Background: Some genetic factors are involved in the etiology of Hashimoto thyroiditis and Graves' disease as autoimmune thyroid diseases (AITDs). Effects of vitamin D receptor gene polymorphisms in AITDs development have already been investigated in some previous studies. However, no study has been done on the association between VDR FokI and ApaI polymorphisms and AITDs in an Iranian population. In this study, the possible effects of FokI and ApaI polymorphisms on AITDs were investigated in the population of northwest of Iran. Methods: A total of 121 AITDs adult patients and 117 healthy controls matched by age and sex in the same population were included in this study. FokI and ApaI polymorphisms were genotyped by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). Chi-square test and odds ratio (OR) with 95% CI were used to analyze the data. Results: FokI and ApaI genotypes frequencies were not significantly different between the 2 groups (p= 0.06, p= 0.73, respectively). However, FokI "CC" and "CT" genotypes were related to AITDs risk (p= 0.03; OR= 3.75; 95% CI, 1.16-12.17 and p= 0.04; OR= 3.41; 95% CI, 1.03-11.28, respectively). Conclusion: These data suggest that FokI polymorphisms are involved in AITDs susceptibility in the population of northwest of Iran.
RESUMO
Functional significance of the neural oscillations has been debated since long. In particular, oscillations have been suggested to play a major role in formation of communication channels between brain regions. It has been previously suggested that gamma coherence increases during communication between hemispheres when subjects perceive a horizontal motion in Stroboscopic Alternative Motion (SAM) stimulus. In addition, disruption of this coherence may change the horizontal perception of SAM. In this study, we investigated the changes of Cross-Frequency Coupling (CFC) in EEG signals from parietal and occipital cortices during horizontal and vertical perception of SAM. Our results suggested that while the strength of CFC in parietal electrodes showed no significant change, CFC in P3-P4 electrode-pair demonstrated a significant correlation during horizontal perception of SAM. Therefore, the CFC between theta- and gamma-band oscillations seems to be correlated with changes in functional interactions between brain regions. Accordingly, we propose that in addition to gamma coherence, CFC is perhaps another neurophysiological mechanism involved in neural communication.
Assuntos
Ritmo Gama/fisiologia , Percepção de Movimento/fisiologia , Lobo Occipital/fisiologia , Lobo Parietal/fisiologia , Ritmo Teta/fisiologia , Eletroencefalografia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Estimulação Luminosa , Adulto JovemRESUMO
BACKGROUND: Clay has been used for its nutrition, cosmetic, and antibacterial properties for thousands of years. Its small particle size, large surface area, and high concentration of ions have made it an interesting subject for pharmaceutical research. There have been studies on scavenging foreign substances and antibacterial properties of clay minerals. The main problem with the medical use of these agents, today, is their heavy metal toxicity. This includes arsenic, cadmium, lead, nickel, zinc, and iron. Iranian traditional medicine (ITM) introduces different clays as medicaments. In this system, there are specific processes for these agents, which might reduce the chance of heavy metal toxicity. Armenian bole is a type of clay that has been used to treat a wound. Before in vivo studies of this clay, its safety should be confirmed. METHODS: In this work, we investigated the effect of washing process as mentioned in ITM books regarding the presence of Pb, As, and Cd in 5 samples using atomic absorption spectrometry. We washed each sample (50 g) with 500 cc of distilled water. The samples were filtered and dried at room temperature for 24 hours. RESULTS: In all studied samples, the amount of Pb and Cd was reduced after the ITM washing process. The amount of As was reduced in 3 samples and increased in 2 other samples. CONCLUSION: In ITM books, there are general considerations for the use of medicinal clay. These agents should not be used before special treatments such as the washing process. In this study, we observed the effect of washing process on reducing the amount of heavy metals in Armenian bole samples. In two samples, washing caused an increase in the amount of As. As these heavy metals sediment according to their density in different layers, the sample layer on which the spectrometry is performed could have an effect on the results.
RESUMO
BACKGROUND: Nowadays, magnetic nanoparticles (MNPs) have received much attention because of their enormous potentials in many fields such as magnetic fluid hyperthermia (MFH). The goal of hyperthermia is to increase the temperature of malignant cells to destroy them without any lethal effect on normal tissues. To investigate the effectiveness of cancer therapy by magnetic fluid hyperthermia, Fe0.5Zn0.5Fe2O4 nanoparticles (FNPs) were used to undergo external magnetic field (f=515 kHz, H=100 G) in mice bearing implanted tumor. METHODS: FNPs were synthesized via precipitation and characterized using transmission electron microscopy (TEM), vibrating sample magnetometer, and Fourier transform infrared. For in vivo study, the mice bearing implanted tumor were divided into four groups (two mice per group), namely, control group, AMF group, MNPs group, and MNPs&AMF group. After 24 hours, the mice were sacrificed and each tumor specimen was prepared for histological analyses. The necrotic surface area was estimated by using graticule (Olympus, Japan) on tumor slides. RESULTS: The mean diameter of FNPs was estimated around 9 nm by TEM image and M versus H curve indicates that this particle is among superparamagnetic materials. According to histological analyses, no significant difference in necrosis extent was observed among the four groups. CONCLUSION: FNPs are biocompatible and have a good size for biomedical applications. However, for MFH approach, larger diameters especially in the range of ferromagnetic particles due to hysteresis loss can induce efficient heat in the target region.
RESUMO
BACKGROUND: Two-dimensional projection radiographs have been traditionally considered the modality of choice for cephalometric analysis. To overcome the shortcomings of two-dimensional images, three-dimensional computed tomography (CT) has been used to evaluate craniofacial structures. However, manual landmark detection depends on medical expertise, and the process is time-consuming. The present study was designed to produce software capable of automated localization of craniofacial landmarks on cone beam (CB) CT images based on image registration and to evaluate its accuracy. METHODS: The software was designed using MATLAB programming language. The technique was a combination of feature-based (principal axes registration) and voxel similarity-based methods for image registration. A total of 8 CBCT images were selected as our reference images for creating a head atlas. Then, 20 CBCT images were randomly selected as the test images for evaluating the method. Three experts twice located 14 landmarks in all 28 CBCT images during two examinations set 6 weeks apart. The differences in the distances of coordinates of each landmark on each image between manual and automated detection methods were calculated and reported as mean errors. RESULTS: The combined intraclass correlation coefficient for intraobserver reliability was 0.89 and for interobserver reliability 0.87 (95% confidence interval, 0.82 to 0.93). The mean errors of all 14 landmarks were <4 mm. Additionally, 63.57% of landmarks had a mean error of <3 mm compared with manual detection (gold standard method). CONCLUSION: The accuracy of our approach for automated localization of craniofacial landmarks, which was based on combining feature-based and voxel similarity-based methods for image registration, was acceptable. Nevertheless we recommend repetition of this study using other techniques, such as intensity-based methods.
Assuntos
Cefalometria/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Crânio/diagnóstico por imagem , Adolescente , Adulto , Criança , Humanos , Imageamento Tridimensional/métodos , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Design de Software , Adulto JovemRESUMO
The use of lasers has emerged to be highly promising for cancer therapy modalities, most commonly, the photothermal therapy method. Unfortunately, the most common disadvantage of laser therapy is its nonselectivity and requirement of high power density. The use of plasmonic nanoparticles as highly enhanced photoabsorbing agents has thus introduced a much more selective and efficient cancer therapy strategy. In this study, we aimed to demonstrate the selective targeting and destruction of mouth epidermal carcinoma cells (KB cells) using the photothermal therapy of folate-conjugated gold nanorods (F-GNRs). Considering the beneficial characteristics of GNRs and overexpression of the folate receptor by KB cells, we selected F-GNRs as a targeted photothermal therapy agent. Cell viability was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was determined by flow cytometry using an annexin V-fluorescein isothiocyanate/propidium iodide apoptosis detection kit. No cell damage or cytotoxicity from the individual treatment of laser light or F-GNRs was observed. However, a 56% cell lethality was achieved for KB cells using combined plasmonic photothermal therapy of 20 µM F-GNRs with seven pulses of laser light and 6-h incubation periods. Cell lethality strongly depends on the concentration of F-GNRs and the incubation period that is mainly due to the induction of apoptosis. This targeted damage is due to the F-GNRs present in the cancer cells strongly absorbing near-infrared laser light and rapidly converting it to heat. This new therapeutic avenue for cancer therapy merits further investigation using in vivo models for application in humans.
Assuntos
Epiderme/patologia , Ácido Fólico/uso terapêutico , Ouro/química , Hipertermia Induzida , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/radioterapia , Nanotubos/química , Fototerapia , Anexina A5/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Epiderme/efeitos dos fármacos , Epiderme/efeitos da radiação , Ácido Fólico/farmacologia , Ouro/toxicidade , Humanos , Raios Infravermelhos , Lasers , Neoplasias Bucais/patologia , Nanotubos/toxicidade , Espectrofotometria UltravioletaRESUMO
Background and Objective: When the uterus is or more than 18 to 20 weeks in size, laparotomy but not minimally invasive surgery (MIS) is commonly performed for hysterectomy. It is, however, acknowledged that MIS carries numerous benefits to patients compared to laparotomy. The uterine size should therefore not be an excluding factor for MIS. This study aims to demonstrate the feasibility and benefits of MIS for hysterectomy for large uterus and explain specific techniques employed. Methods: Data from 73 laparoscopic and robotic hysterectomy cases were collected. Cases were divided in two groups based on uterine weight (≥500 g vs <500 g). Estimated blood loss (EBL), operative time, length of hospital stays, and perioperative complications were compared between the groups. Results: The average specimen weight in two groups was 244 ± 102.75 g vs 903 ± 438.18 g (P < .01). There was no statistically significant difference in length of hospital stay between the two groups. Only 3 patients were hospitalized for more than one day. There were no instances of conversion to laparotomy, intraoperative or postoperative blood transfusion. There was a statistically significant difference in the EBL (78.19 ± 43.8 ml vs 127.88 ± 69.76 ml, P < .01) and operative time (180.68 ± 48.36 vs 228.85 ± 53.04 minutes, P < .01) between the two groups. There were two cases of bladder laceration in the group with uterine weight exceeding 500 g. Conclusion: With advanced surgical skills and the adoption of specific techniques, hysterectomy for large uterus can be performed safely and efficiently by MIS.
Assuntos
Histerectomia , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Útero , Humanos , Feminino , Histerectomia/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Útero/cirurgia , Laparoscopia/métodos , Adulto , Pessoa de Meia-Idade , Tempo de Internação/estatística & dados numéricos , Duração da Cirurgia , Tamanho do Órgão , Estudos Retrospectivos , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Estudos de Viabilidade , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Complicações Pós-Operatórias/epidemiologiaRESUMO
PURPOSE OBJECTIVE(S): Manual contouring of the prostate region in planning computed tomography (CT) images is a challenging task due to factors such as low contrast in soft tissues, inter- and intra-observer variability, and variations in organ size and shape. Consequently, the use of automated contouring methods can offer significant advantages. In this study, we aimed to investigate automated male pelvic multi-organ contouring in multi-center planning CT images using a hybrid convolutional neural network-vision transformer (CNN-ViT) that combines convolutional and ViT techniques. MATERIALS/METHODS: We used retrospective data from 104 localized prostate cancer patients, with delineations of the clinical target volume (CTV) and critical organs at risk (OAR) for external beam radiotherapy. We introduced a novel attention-based fusion module that merges detailed features extracted through convolution with the global features obtained through the ViT. RESULTS: The average dice similarity coefficients (DSCs) achieved by VGG16-UNet-ViT for the prostate, bladder, rectum, right femoral head (RFH), and left femoral head (LFH) were 91.75%, 95.32%, 87.00%, 96.30%, and 96.34%, respectively. Experiments conducted on multi-center planning CT images indicate that combining the ViT structure with the CNN network resulted in superior performance for all organs compared to pure CNN and transformer architectures. Furthermore, the proposed method achieves more precise contours compared to state-of-the-art techniques. CONCLUSION: Results demonstrate that integrating ViT into CNN architectures significantly improves segmentation performance. These results show promise as a reliable and efficient tool to facilitate prostate radiotherapy treatment planning.
RESUMO
Modern scientific achievements in the field of contraception are clearly indebted to past studies. Al-Akhawayni Bukhari was a Persian physician in the 10th century. He lived during the 'Golden Age of Islamic Medicine' (9th to 12th century AD). This scientist recorded his knowledge on various medical matters, including contraception, in the book 'Hidayat al-Muta`allemin Fi al-Tibb' (Learner's Guide to Medicine). These 10th century views on contraception are explored in this paper through a discussion of Al-Akhawayni Bukhari's surviving book, the 'Hidayat' (Guide).
Assuntos
Aborto Induzido/história , Anticoncepção/história , Espermicidas/história , Feminino , História Antiga , História Medieval , Humanos , Neuropsiquiatria/história , PérsiaRESUMO
Microelectrode Arrays (MEAs) neural interfaces are considered implantable devices that interact with the nervous system to monitor and/or modulate brain activity. Graphene-based materials are utilized to address some of the current challenges in neural interface design due to their desirable features, such as high conductance, large surface-to-volume ratio, suitable electrochemical properties, biocompatibility, flexibility, and ease of production. In the current study, we fabricated and characterized a type of flexible, ultrasmall, and implantable neurostimulator based on graphene fibers. In this procedure, wet-spinning was employed to create graphene fibers with diameters of 10 to 50 µm. A 10-channel polyimide Printed Circuit Board (PCB) was then custom-designed and manufactured. The fibers were attached to each channel by conductive glue and also insulated by soaking them in a polyurethane solution. The tips were subsequently exposed using a blowtorch. Microstructural information on the fibers was obtained using Scanning Electron Microscopy (SEM), and the measurements of Electrochemical Impedance Spectroscopy (EIS) were conducted for each electrode. Flexible MEAs were created using graphene fibers with diameters ranging from 10 to 50 microns with a spacing of 150 microns. This method leads to producing electrode arrays with any size of fibers and a variety of channel numbers. The flexible neural prostheses can replace conventional electrodes in both neuroscience and biomedical research.
RESUMO
Objectives. Detection of sensitive signs in many work environments with automated systems (aviation industry, flight safety tower, maritime industry, monitoring in the military industry, etc.) is essential and requires constant visual attention. Therefore, the aim of this study was to investigate the effect of forehead cooling on the accuracy of stable visual attention. Methods. This interventional study was performed on 34 male students. The sampling method was a randomized block design. Subjects were assessed by demographic questionnaire, Snellen chart, Spielberger state-trait anxiety inventory (STAI) and physiological and cognitive measurements. Results. Prefrontal cortex (PFC) cooling caused significant changes in sublingual temperature during four measurements in the intervention group. There were no significant changes in heart rate, diastolic blood pressure and saturation of peripheral oxygen (%SpO2) between the two groups. The critical flicker frequency (CFF) as an indicator of cognitive fatigue showed that cognitive improvement after PFC cooling occurred following a reduction in cognitive fatigue. Conclusions. Considering the importance of choosing non-invasive methods to improve the operator's cognitive skills while performing cognitive tasks in the field of neuroergonomics, it can be concluded that PFC cooling is an effective and safe way to improve some cognitive skills such as visual attention.
Assuntos
Aviação , Humanos , Masculino , Temperatura , Frequência Cardíaca , Córtex Pré-Frontal/fisiologiaRESUMO
Mucormycosis is a rare opportunistic devastating fungal infection, which usually occurs in immunocompromised patients. Mucormycosis has multiple presentations that the predilection for one of these presentations varies with the either underlying or predisposing condition. We present a case of pulmonary and rhinocerberal mucormycosis in 56-year-old man with diabetic ketoacidosis.
Assuntos
Cetoacidose Diabética/complicações , Pneumopatias Fúngicas/etiologia , Mucormicose/etiologia , Complicações do Diabetes/diagnóstico , Cetoacidose Diabética/diagnóstico , Humanos , Pneumopatias Fúngicas/diagnóstico , Masculino , Pessoa de Meia-Idade , Mucormicose/diagnósticoRESUMO
Medical sciences including pharmacy flourished in Persia throughout medieval times. The oldest pharmacopeias which discussed pharmaceutical formulations were created by them, called Qarabadin. Among various dosage forms which were described, Jawarish was a gastrointestinal dosage form which was made from different ingredients for different purposes such as stomach tonic, digestive, carminative, laxative, astringent, visceral analgesic, antihaemorrhoid, antiemetic, emetic, antireflux and anticolic. This paper, introduces their preparation, general considerations and five common examples of Jawarish.
Assuntos
Química Farmacêutica/história , Fármacos Gastrointestinais/história , Farmacopeias como Assunto/história , Formas de Dosagem , Fármacos Gastrointestinais/análise , Fármacos Gastrointestinais/química , História Medieval , Humanos , Irã (Geográfico) , PérsiaRESUMO
BACKGROUND: Controlling upright posture entails acute adjustments by the neuromuscular system to keep the center of mass (COM) within the limits of a relatively small base of support. Sudden displacement of the COM triggers several strategies and balance recovery mechanisms to prevent excessive COM displacement. NEW METHOD: We have examined and quantified a new approach to induce an internal neuromuscular perturbation in standing posture on 15 healthy individuals to provide an insight into the mechanism of loss of balance (LOB). The method comprises eliciting an H-reflex protocol while subjects are standing which produces a contraction in soleus and gastrocnemius muscles. We have also defined analytical techniques to provide biomarkers of balance control during perturbation. We used M-Max unilaterally or bilaterally and induced a forward or sideway perturbation. The vector analysis and the Equilibrium Point calculations defined here can quantify the amplitude, direction, and evolution of the perturbation. RESULTS: Clear patterns of loss of balance due to stimulation was observed. Compared to quiet standing, the density of the EPs substantially increased in the perturbation phase. Leftward stimulation produced significantly higher number of EPs compared to the bilateral stimulation condition which could be due to the fact that the left leg was the nondominant side in all our subjects. COMPARISON AND CONCLUSION: In this study we provide a proof-of-concept technique for examining recovery from perturbation. The advantage of this technique is that it provides a safe perturbation, is internally induced at the spinal cord level, and is free from other factors that might complicate the recovery analysis (e.g., locomotion and the integration of the spinal pattern generator and cutaneous pathways in mediating changes). We have shown that the perturbation induced by this method can be quantified as vectors. We have also shown that the density of instantaneous equilibrium points (EPs) could be a good biomarker for defining and examining the perturbation phase. Thus, this protocol and analysis provides a unique individual assessment of recovery which can be used to assess interventions. Finally, given that the maximal motor response is used as the perturbation (e.g., M-max) it is highly reliable and reproducible within an individual patient.
Assuntos
Reflexo H , Equilíbrio Postural/fisiologia , Postura/fisiologia , Estimulação Elétrica , Eletromiografia , Reflexo H/fisiologia , Humanos , Perna (Membro)/fisiologia , Músculo Esquelético/fisiologiaRESUMO
OBJECTIVES: Our study aimed to apply the apparent diffusion coefficient (ADC) values to quantify the differences between low- and high-grade glioma tumors. METHODS: We conducted a multicenter, retrospective study between September to December 2019. Magnetic resonance imaging (MRI) diffusion-weighted images (DWIs), and the pathologic findings of 56 patients with glioma tumors (low grade = 28 and high grade = 28) were assessed to measure the ADC values in the tumor center, tumor edema, boundary area between tumor with normal tissue, and inside the healthy hemisphere. These values were compared between the two groups, and cut-off values were calculated using the receiver operating characteristic curve. RESULTS: We saw significant differences between the mean ADC values measured in the tumor center and edema between high- and low-grade tumors (p< 0.005). The ADC values in the boundary area between tumors with normal tissue and inside healthy hemisphere did not significantly differ in the groups. The ADC values at tumor center and edema were higher than 1.12 × 10-3 mm2/s (sensitivity = 100% and specificity = 96.0%) and 1.15 × 10-3 mm2/s (sensitivity = 75.0% and specificity = 64.0%), respectively, could be classified as low-grade tumors. CONCLUSIONS: The ADC values from the MRI DWIs in the tumor center and edema could be used as an appropriate method for investigating the differences between low- and high-grade glioma tumors. The ADC values in the boundary area and healthy tissues had no diagnostic values in grading the glioma tumors.