scholarly journals Combined Ultrasound Imaging and Biomechanical Modeling to Estimate Triceps Brachii Musculotendon Changes in Stroke Survivors

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Le Li ◽  
Raymond Kai-yu Tong

The aim of this study was to investigate the changes of musculotendon parameters of triceps brachii in persons after stroke based on subject-specific biomechanical modeling technique combined with in vivo ultrasound measurement. Five chronic stroke survivors and five normal control subjects were recruited. B-mode ultrasound was applied to measure muscle pennation angle and the optimal length of three heads of triceps’ brachii at different joint angle positions in resting and isometric contraction. Measured ultrasound data were used to reduce the unknown parameters during the modeling optimization process. The results showed that pennation angles varied with joint angles, and the longhead TRI pennation from stroke group was smaller than the literature value. The maximum isometric muscle stress from persons after stroke was significantly smaller than that found in the unimpaired subjects. The prediction of joint torque fits well with the measured data from the control group, whereas the prediction error is larger in results from persons after stroke. In vivo parameters from ultrasound data could help to build a subject-specific biomechanical model of elbow extensor for both unimpaired and hemiplegic subjects, and then the results driven from the model could enhance the understanding of motor function changes for persons after stroke.

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Mitsuhiro Hayashibe ◽  
David Guiraud ◽  
Philippe Poignet

Skeletal muscle system has nonlinear dynamics and subject-specific characteristics. Thus, it is essential to identify the unknown parameters from noisy biomedical signals to improve the modeling accuracy in neuroprosthetic control. The objective of this work is to develop an experimental identification method for subject-specific biomechanical parameters of a physiological muscle model which can be employed to predict the nonlinear force properties of stimulated muscle. Our previously proposed muscle model, which can describe multiscale physiological system based on the Hill and Huxley models, was used for the identification. The identification protocols were performed on two rabbit experiments, where the medial gastrocnemius was attached to a motorized lever system to record the force by the nerve stimulation. The muscle model was identified using nonlinear Kalman filters: sigma-point and extended Kalman filter. The identified model was evaluated by comparison with experimental measurements in the cross-validation manner. The feasibility could be demonstrated by comparison between the estimated parameter and the measured value. The estimates with SPKF showed 5.7% and 2.9% error in each experiment with 7 different initial conditions. It reveals that SPKF has great advantage especially for the identification of multiscale muscle model which accounts for the high nonlinearity and discontinuous states between muscle contraction and relaxation process.


Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.


1990 ◽  
Vol 29 (03) ◽  
pp. 120-124
Author(s):  
R. P. Baum ◽  
E. Rohrbach ◽  
G. Hör ◽  
B. Kornhuber ◽  
E. Busse

The effect of triiodothyronine (T3) on the differentiation of cultured neuroblastoma (NB) cells was studied after 9 days of treatment with a dose of 10-4 M/106 cells per day. Using phase contrast microscopy, 30-50% of NB cells showed formation of neurites as a morphological sign of cellular differentiation. The initial rise of the mitosis rate was followed by a plateau. Changes in cyclic nucleotide content, in the triphosphates and in the activity of the enzyme ornithine decarboxylase (ODC) were assessed in 2 human and 2 murine cell lines to serve as biochemical parameters of the cell differentiation induced by T3. Whereas the cAMP level increased significantly (3 to 7 fold compared with its initial value), the cGMP value dropped to 30 to 50% of that of the control group. ATP and GTP increased about 200%, the ODC showed a decrease of about 50%. The present studies show a biphasic effect of T3 on neuroblastoma cells: the initial rise of mitotic activity is followed by increased cell differentiation starting from day 4 of the treatment.


1972 ◽  
Vol 27 (01) ◽  
pp. 114-120 ◽  
Author(s):  
A. A Hassanein ◽  
Th. A El-Garf ◽  
Z El-Baz

SummaryADP-induced platelet aggregation and calcium-induced platelet aggregation tests were studied in 14 diabetic patients in the fasting state and half an hour after an intravenous injection of 0.1 unit insulin/kg body weight. Platelet disaggregation was significantly diminished as compared to a normal control group, and their results were negatively correlated with the corresponding serum cholesterol levels. Insulin caused significant diminution in the ADP-induced platelet aggregation as a result of rapid onset of aggregation and disaggregation. There was also a significant increase in platelet disaggregation. In the calcium-induced platelet aggregation test, there was a significant shortening of the aggregation time, its duration, and the clotting time. The optical density fall due to platelet aggregation showed a significant increase. Insulin may have a role in correcting platelet disaggregation possibly through improvement in the intracellular enzymatic activity.


1970 ◽  
Vol 23 (02) ◽  
pp. 386-404 ◽  
Author(s):  
G Müller-Berghaus ◽  
H. G Lasch

SummaryThe role of Hageman factor in triggering intravascular coagulation has been studied in rabbits injected intravenously with Liquoid. Besides changes of coagulation parameters characteristic of consumption coagulopathy (e.g. decrease in platelet counts, fibrinogen levels, factor V activity), a pronounced drop in Hageman factor activity was observed after injection of Liquoid. Likewise, the partial thromboplastin time became prolonged.The activation of Hageman factor in vivo could be prevented by intravenous infusion of lysozyme. Twenty min after starting the lysozyme infusion, the partial thromboplastin time became prolonged from a mean of 29 sec to 108 sec. Animals infused with lysozyme and injected with a lethal dose of Liquoid did not develop a consumption coagulopathy. In the same manner, none of 10 animals treated with lysozyme developed the generalized Shwartzman reaction, whereas in the control group 19 out of 20 animals showed fibrin thrombi in the glomerular capillaries.From the present study it may be concluded that the intravascular coagulation process after intravenous injection of Liquoid is triggered by Hageman factor activation.


Author(s):  
Ni Made Ridla Parwata

Overtraining syndrome is a decrease in physical capacity, emotions and immunity due to training that is too often without adequate periods of rest. Overtraining is often experienced by athletes who daily undergo heavy training with short break periods. This research aims to look at the effect of overtraining aerobic physical exercise on memory in mice. The research method was experimental in vivo with the subject of adult male rat (Rattus Norvegicus) Winstar strain aged 8-10 weeks, body weight 200-250 gr. Divided into three groups, namely the control group, aerobic group and overtraining group. The results of memory tests with water E Maze showed an increase in the duration of travel time and the number of animal errors made by the overtraining group (p = 0.003). This study concludes that overtraining aerobic physical exercise can reduce memory in rat hippocampus.


2020 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Henas Deliara ◽  
Arum Kartikadewi ◽  
Dyah Mustika Nugraheni

Latar Belakang: Hiperkolesterolemia dapat menyebabkan penyakit cerebrovaskuler bahkan kematian. Salah satu pencegahan hiperkolesterolemia adalah dengan pemberian suplemen contohnya menggunakan kulit jeruk purut (Citrus hystrix) yang mengandung saponin, tanin dan flavonoid. Tujuan penelitian ini adalah membuktikan adanya pengaruh pemberian ekstrak ethanol kulit jeruk purut terhadap kadar kolesterol total pada tikus wistar jantan yang diberi diet tinggi lemak. Metode: Penelitian eksperimental  ini menggunakan metode post test only control group design. Jumlah sampel 30 ekor tikus wistar jantan dikelompokkan secara simple random sampling menjadi kelompok kontrol negative (K-), kontrol positif (K+), perlakuan 1 (P1), perlakuan 2 (P2) dan perlakuan 3 (P3). Pada kelompok K+, P1,P2 dan P3 tikus diberi minyak babi sebanyak 3 mg/200grBB/hari selama 3 minggu. Kelompok P1, P2 dan P3 diberikan ekstrak ethanol kulit jeruk purut sebesar 35 mg/200grBB/hari, 70 mg/200grBB/hari, dan 140 mg/200grBB/hari selama 3 minggu. Kadar kolesterol total dihitung dengan metode CHOD-PAP lalu dianalisis secara statistic dengan uji One Way Annova dan uji beda dengan Pos Hoc. Hasil: Dari 25 sampel, rerata kadar kolesterol total (K-):73,90 mg/dl±19,11 mg/dl; (K+):80,00 mg/dl±4,72 mg/dl; (P1):69,94 mg/dl±6,52 mg/dl; (P2):59,10 mg/dl±11,70 mg/dl; (P3):59,74 mg/dl±7,52 mg/dl. (p=0,032). Hasil uji Pos Hoc kelompok yang berbeda signifikan adalah K- dengan P2 (p=0,049), K+ dengan P2 (p=0,008) dan K+ dengan P3 (p=0,010). Kesimpulan: Terdapat pengaruh pemberian ekstrak ethanol kulit jeruk purut terhadap kadar kolesterol total pada tikus wistar jantan yang diberi diet tinggi lemak. Dosis terendah ekstrak kulit jeruk purut yang dapat menurunkan kadar kolesterol total adalah 70 mg/200 grBB/hari.


2020 ◽  
Author(s):  
K. Zerrouki ◽  
N. Djebli ◽  
L. Gadouche ◽  
I. Erdogan Orhan ◽  
F. SezerSenol Deniz ◽  
...  

Nowadays, because of the industrialization, a lot of contaminant were available ; the consequences of this availability are apparition of diseases including neurodegeneration. Neurodegenerative diseases of the human brain comprise a variety of disorders that affect an increasing percentage of the population. This study is based on the effect of the Boswellic resin, which is from a medicinal plant and known for its antioxidant effects on nerve cell damage. The objective of this work was to evaluate the in vitro and in vivo effects of the Boswellic resin on anticholinesterase activity and Alzheimer’s disease (AD) induced by D-galactose and aluminum tetrachloride in Swiss mice. Chemical composition of the resin essential oil was identified by the CG-MS analysis. The antioxidant activity was also assessed by the DMPD and metal chelation methods. In order to understand the mechanism of memory improvement, the acetylcholinesterase, AChE, and butyrylcholinesterase, BChE, inhibitory assays were performed. In vivo part of the study was achieved on Swiss mice divided into four groups: control, AD model, treated AD, and treated control group. The identification of chemical composition by CG-MS reach the 89.67% of the total extract compounds presented some very important molecules (p-Cymene, n-Octyl acetate, α-Pinene…). The present study proves that Boswellic resin improves memory and learning in treated Alzheimer’s group, modulates the oxidative stress and be involved in the protective effect against amyloid deposition and neurodegeneration, and stimulates the immune system in mice’s brain.


2017 ◽  
Vol 68 (7) ◽  
pp. 1506-1511
Author(s):  
Cerasela Mihaela Goidescu ◽  
Anca Daniela Farcas ◽  
Florin Petru Anton ◽  
Luminita Animarie Vida Simiti

Oxidative stress (OS) is increased in chronic diseases, including cardiovascular (CV), but there are few data on its effects on the heart and vessels. The isoprostanes (IsoP) are bioactive compounds, with 8-iso-PGF25a being the most representative in vivo marker of OS. They correlate with the severity of heart failure (HF), but because data regarding OS levels in different types of HF are scarce, our study was aimed to evaluate it by assessing the urinary levels of 8-iso-PGF2aand its correlations with various biomarkers and parameters. Our prospective study included 53 consecutive patients with HF secondary to ischemic heart disease or dilative cardiomyopathy, divided according to the type of HF (acute, chronic decompensated or chronic compensated HF). The control group included 13 hypertensive patients, effectively treated. They underwent clinical, laboratory - serum NT-proBNP, creatinine, uric acid, lipids, C reactive protein (CRP) and urinary 8-iso-PGF2a and echocardiographic assessment. HF patients, regardless the type of HF, had higher 8-iso-PGF2a than controls (267.32pg/�mol vs. 19.82pg/�mol, p[0.001). The IsoP level was directly correlated with ejection fraction (EF) (r=-0.31, p=0.01) and NT-proBNP level (r=0.29, p=0.019). The relative wall thickness (RWT) was negatively correlated with IsoP (r=-0.55, p[0.001). Also 8-iso-PGF25a was higher by 213.59pg/�mol in the eccentric left ventricular (LV) hypertrophy subgroup comparing with the concentric subgroup (p=0.014), and the subgroups with severe mitral regurgitation (MR) and moderate/severe pulmonary hypertension (PAH) had the highest 8-iso-PGF2a levels. Male sex, severe MR, moderate/severe PAH, high LV mass and low RWT values were predictive for high OS level in HF patients.Eccentric cardiac remodeling, MR severity and PAH severity are independent predictors of OS in HF patients.


2020 ◽  
Vol 15 (1) ◽  
pp. 70-77
Author(s):  
Junhe Zhang ◽  
Weihua Dong

Background: Esophageal carcinoma is one of the common malignant tumors in digestive tract. BECLIN-1 is a key gene that regulates autophagy, and its abnormal expression may be related with many human tumors. However, the mechanism of BECLIN-1 in esophageal carcinoma remains unknown. Objective: In this study, we explored the effect of BECLIN-1 overexpression on tumor growth in mice with esophageal carcinoma and its mechanism. Methods: Recombined lentiviral vector containing BECLIN-1 was used to transfect human esophageal carcinoma Eca109 cells and establish stable cell line. qRT-PCR was used to detect BECLIN-1 mRNA level in the transfected Eca109 cells, CCK-8 assay was used to detect cell proliferation. Beclin-1, P62 and LC3-II protein expression levels in Eca109 cells were detected using Western blot analysis. Subcutaneous xenograft nude mice model of human esophageal carcinoma was established, and the tumor growths in Beclin-1 group, control group and empty vector group were monitored. Beclin-1 protein expression in vivo was detected by immunohistochemistry. Results: Beclin-1 mRNA and protein were overexpressed in Eca109 cells. Compared with empty vector group, the growth rate of cells transfected with BECLIN-1 decreased significantly. Compared with the control group and empty vector group, the expression level of P62 protein in beclin-1 group was significantly decreased, while the expression level of LC3-II protein was significantly increased. The tumor growth rate in nude mice of Beclin-1 group was significantly lower than that of the control group and empty vector group, and Beclin-1 protein was mainly expressed in Beclin-1 group in vivo. Conclusion: BECLIN-1 can induce autophagy in esophageal carcinoma Eca109 cells, and it can significantly inhibit the growth of esophageal carcinoma.


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