BIOMECHANICAL ANALYSIS OF THE EVADING WITH PUSHING TECHNIQUE IN TAI CHI PUSH HANDS

The traditional Chinese martial arts, Tai Chi (TC), include different forms and advanced interactive movements called Push Hands. Very few studies on the biomechanics analysis of TC push hands have been published. To investigate the characteristics of Tai Chi Push Hands, an experienced master was asked to perform the ‘evading with pushing technique’ when he was pushed by another person for three trials. The master’s movements were videotaped and digitized using a motion analysis system combining electromyography and force plate data. The results indicated that the master lowered his COG, shifted his body weight to rear foot, twisted his waist to evade the push, and pushed back with the strength from the lower limbs. It is concluded that the evading with pushing technique is a efficient and effective way to strike back

KINEMATIC ANALYSIS OF THE SUPPORTING LEG BETWEEN DIFFERENT WEIGHT DIVISIONS IN THE ROUNDHOUSE KICK OF TAEKWONDO

The purpose of this study was to compare kinematic differences in the supporting leg between two weight divisions in the Taekwondo Roundhouse Kick. Collegiate Taekwondo athletes participated in the study and differences in maximum joint angles and ranges of motion on the supporting leg during executing the Roundhouse Kick were examined. The results showed significantly larger (

Radiation inactivation analysis of H+-pyrophosphatase from submitochondrial particles of etiolated mung bean seedlings

AbstractRadiation inactivation analysis was employed to determine the functional masses of enzymatic activity and proton translocation of H+-pyrophosphatase from submitochondrial particles of etiolated mung bean seedlings. The activities of H+-pyrophosphatase decayed as a simple exponential function with respect to radiation dosage. D37 values of 6.9±0.3 and 7.5±0.5 Mrad were obtained for pyrophosphate hydrolysis and its associated proton translocation, yielding molecular masses of 170±7 and 156±11 kDa, respectively. In the presence of valinomycin and 50 mM KCl, the functional size of H+-pyrophosphatase of tonoplast was decreased, while that of submitochondrial particles remained the same, indicating that they are two distinct types of proton pump using PPi as their energy source

Interactions between Amyloid-β and Hemoglobin: Implications for Amyloid Plaque Formation in Alzheimer's Disease

Accumulation of amyloid-β (Aβ) peptides in the brain is one of the central pathogenic events in Alzheimer's disease (AD). However, why and how Aβ aggregates within the brain of AD patients remains elusive. Previously, we demonstrated hemoglobin (Hb) binds to Aβ and co-localizes with the plaque and vascular amyloid deposits in post-mortem AD brains. In this study, we further characterize the interactions between Hb and Aβ in vitro and in vivo and report the following observations: 1) the binding of Hb to Aβ required iron-containing heme; 2) other heme-containing proteins, such as myoglobin and cytochrome C, also bound to Aβ; 3) hemin-induced cytotoxicity was reduced in neuroblastoma cells by low levels of Aβ; 4) Hb was detected in neurons and glial cells of post-mortem AD brains and was up-regulated in aging and APP/PS1 transgenic mice; 5) microinjection of human Hb into the dorsal hippocampi of the APP/PS1 transgenic mice induced the formation of an envelope-like structure composed of Aβ surrounding the Hb droplets. Our results reveal an enhanced endogenous expression of Hb in aging brain cells, probably serving as a compensatory mechanism against hypoxia. In addition, Aβ binds to Hb and other hemoproteins via the iron-containing heme moiety, thereby reducing Hb/heme/iron-induced cytotoxicity. As some of the brain Hb could be derived from the peripheral circulation due to a compromised blood-brain barrier frequently observed in aged and AD brains, our work also suggests the genesis of some plaques may be a consequence of sustained amyloid accretion at sites of vascular injury

Concurrent Papillary Thyroid Cancer with Pituitary ACTH-secreting Tumor

Concomitant thyroid cancer with pituitary tumor is uncommon. This study reports a case of advanced papillary thyroid carcinoma with pituitary adrenocorticotropic hormone (ACTH)-secreting tumor. A 58-year-old male patient had thyroid cancer in 1991 and presented with headache caused by pituitary tumor with apoplexy in 1993. Due to hypopituitarism, the patient underwent radioactive iodide (131I) for detection and treatment of metastatic thyroid cancer after the use of recombinant human thyroid-stimulating hormone (rhTSH) in 2000. During follow-up for thyroid cancer 201thallium scan proved to be an effective tool for detecting metastatic thyroid cancer in the patient without pituitary TSH reserve. Pituitary ACTH-secreting tumor was confirmed in 2001 based on the high serum ACTH level and positive immunohistochemical stain for ACTH. The patient had no Cushingoid features. Moreover, serum ACTH levels were 337 and 232 pg/mL with normal serum cortisol and urine-free cortisol. Although the patient underwent three operations and a total of 370 mCi 131I therapy for recurrent thyroid cancer, the cancer continued to progress. Finally, the patient died of pneumonia with septic shock 12 years after the diagnosis of thyroid cancer. [J Formos Med Assoc 2007;106(4):330-335

Genome-Wide Gene-Environment Interaction Analysis Using Set-Based Association Tests

The identification of gene-environment interactions (G × E) may eventually guide health-related choices and medical interventions for complex diseases. More powerful methods must be developed to identify G × E. The “adaptive combination of Bayes factors method” (ADABF) has been proposed as a powerful genome-wide polygenic approach to detect G × E. In this work, we evaluate its performance when serving as a gene-based G × E test. We compare ADABF with six tests including the “Set-Based gene-EnviRonment InterAction test” (SBERIA), “gene-environment set association test” (GESAT), etc. With extensive simulations, SBERIA and ADABF are found to be more powerful than other G × E tests. However, SBERIA suffers from a power loss when 50% SNP main effects are in the same direction with the SNP × E interaction effects while 50% are in the opposite direction. We further applied these seven G × E methods to the Taiwan Biobank data to explore gene× alcohol interactions on blood pressure levels. The ADAMTS7P1 gene at chromosome 15q25.2 was detected to interact with alcohol consumption on diastolic blood pressure (p = 9.5 × 10−7, according to the GESAT test). At this gene, the P-values provided by other six tests all reached the suggestive significance level (p < 5 × 10−5). Regarding the computation time required for a genome-wide G × E analysis, SBERIA is the fastest method, followed by ADABF. Considering the validity, power performance, robustness, and computation time, ADABF is recommended for genome-wide G × E analyses

Nitroprusside modulates pulmonary vein arrhythmogenic activity

<p>Abstract</p> <p>Background</p> <p>Pulmonary veins (PVs) are the most important sources of ectopic beats with the initiation of paroxysmal atrial fibrillation, or the foci of ectopic atrial tachycardia and focal atrial fibrillation. Elimination of nitric oxide (NO) enhances cardiac triggered activity, and NO can decrease PV arrhythmogensis through mechano-electrical feedback. However, it is not clear whether NO may have direct electrophysiological effects on PV cardiomyocytes. This study is aimed to study the effects of nitroprusside (NO donor), on the ionic currents and arrhythmogenic activity of single cardiomyocytes from the PVs.</p> <p>Methods</p> <p>Single PV cardiomyocytes were isolated from the canine PVs. The action potential and ionic currents were investigated in isolated single canine PV cardiomyocytes before and after sodium nitroprusside (80 μM,) using the whole-cell patch clamp technique.</p> <p>Results</p> <p>Nitroprusside decreased PV cardiomyocytes spontaneous beating rates from 1.7 ± 0.3 Hz to 0.5 ± 0.4 Hz in 9 cells (P < 0.05); suppressed delayed afterdepolarization in 4 (80%) of 5 PV cardiomyocytes. Nitroprusside inhibited L-type calcium currents, transient outward currents and transient inward current, but increased delayed rectified potassium currents.</p> <p>Conclusion</p> <p>Nitroprusside regulates the electrical activity of PV cardiomyocytes, which suggests that NO may play a role in PV arrhythmogenesis.</p

EVALUATION OF ELBOW AND FOREARM MOTION BETWEEN SIDEARM AND OVERHAND PITCHING

This study is to analyze the differences in kinematics, electromyography (EMG) and ultrasonography between two types of pitchers. We intend to observe and simulate the muscles around glenohumeral and elbow joints in different pitching motions and hope to discover the connections and differences in between. 12 pitchers from the top level were recruited. Larger elbow flexion was found in sidearm pitchers during the acceleration phase. Decrease of the distance of nerve to medial epicondyle was also found as the elbow moved to a more flexed position. More anterior translation of the ulnar nerve might occur during acceleration phase. Slightly lower flexor carpi radialis (FCR) activity was displayed in sidearm pitchers, showing that FCR might play a less crucial role in protecting medial elbow by providing less varus torque