1.Electromyogram patterns during ankle joint movements at various angular velocities in the triceps surae muscles.
HIROYUKI TAMAKI ; KOJI KITADA ; HIROSHI KURATA
Japanese Journal of Physical Fitness and Sports Medicine 1993;42(3):292-300
Surface electromyograms (EMGs) were recorded from the triceps surae muscles in order to examine muscle activities during concentric and eccentric ankle joint movements at various angular velocities under constant load (5 and 10%MVC) . The results were summarized as follows ;
1) At slow angular velocity (6 deg/s) of ankle joint movement, EMG amplitude tended to increase at a larger ankle joint angle in the gastrocnemius muscle, and at a smaller angle in the soleus muscle.
2) Following an increase in angular velocities (6→30→60 deg/s), peak values of integrated EMGs were significantly increased (7-15%) in the medial gastrocnemius muscle. However, these peak values were significantly decreased in the soleus muscle (22-49%) . These results suggest selective recruitment of motor units depending on angular velocity.
3) Ankle joint angle at the peak integrated EMGs was significantly increased following an increase in angular velocity (6→30→60 deg/s) in the soleus muscle. This suggests that the angle at the recruitment of motor units may be dependent on angular velocity in the soleus muscle.
2.Changes in activity in triceps surae muscles during prolonged isometric contractions.
HIROYUKI TAMAKI ; KOJI KITADA ; HIROSHI KURATA
Japanese Journal of Physical Fitness and Sports Medicine 1995;44(4):457-464
In order to examine muscle activities, surface electromyo-grams (EMGs) were recorded from the triceps surae muscles (lateral gastrocnemius: LG, medial gastrocnemius: MG, soleus: SOL) during prolonged isometric contractions at 20°of ankle joint angle under constant load (10% MVC) . The results were summarized as follows;
1) EMG recordings were obtained which showed complementary activity in each muscle in the time course. Changes in activity was found between whole muscles in the synergist of triceps surae muscles.
2) Muscle activity most frequently took the form of MG+SOL, followed by MG acting alone and SOL acting alone. Ta/Ts value (the ratio of total activity period and total silent period on EMG activity) showed 4.0 in MG and SOL. In contrast, it showed 0.3 in the LG.
3) In the latter half of all exercise times, frequent changes in activity were shown, and Ta/Ts value increased in the gastrocnemius muscle and decreased in the soleus muscle. These results indicate that frequent changes in activity in the latter half were caused by the reduc tion in Ts in the gastrocnemius muscle, and the reduction in Ta in the soleus muscle.
4) Mean integrated EMGs increased significantly in the middle and latter phases in each burst activity, but those in the latter phase did not increase compared to those in the middle phase. These results suggest that the rotation of activity between muscles may have occured before the remarkable increase of EMG activity with fatigue.
3.Time course of twitch potentiation after tetanic nerve and direct stimulations in the thumb adduction in man.
KOJI KITADA ; HIROYUKI TAMAKI ; HIROSHI KURATA
Japanese Journal of Physical Fitness and Sports Medicine 1996;45(1):227-236
Effects of various tetanic stimulation frequencies (50 Hz, 100 Hz and 200 Hz) on the time course of twitch potentiation were examined in the adduction of human pollicis. Isometric twitch tension curve and surface electromyogram were recorded immediately after (1 sec) the 10 sec-tetanus and at intervals of lOsec (up to 300sec) . The stimulating methods were by nerve and direct stimulations in order to examine the role of nerve on the post-tetanic potentiation. The results were summarized as follows :
1) The greatest potentiation was observed immediately after the tetanus. The potentiation decreased rapidly in the period of 60 sec after the tetanus. Then, the potentiation continued to decrease at the low frequency (50 Hz) ; however, it tended to level off at the high frequencies (100 Hz and 200 Hz) .
2) The time course of twitch potentiation by the nerve stimulation was larger than that by the direct stimulation. This result suggests that nerve has a factor which enhances potentiation. The duration of the potentiation varied according to the stimulation frequencies by the nerve stimulation. It seems that this phenomenon was strongly influenced by the nerve.
3) The degree of increase in twitch tension tended to depend greatly on the peak rate of force development. This result suggests that the increase in twitch tension was closely related to the intensity of the active state.
4) Time course of time to peak tension relatively corresponded to the half relaxation time. It seems possible for the duration of the active state to be related to calcium uptake at the sarcoplasmic reticulum.
5) The coupling efficiency by the direct stimulation tended to be smaller than that by the nerve stimulation after 10 sec. This result suggests that the stimulating nerve possesses a factor which prolongs the period of potentiation.
4.Effects of local cooling and heating in the triceps surae muscles during sustained isometric contraction.
RYOTARO KIME ; HATSUKI SIRASAWA ; HIROYUKI TAMAKI ; HIROSHI KURATA ; TAKAYUKI SAKO ; TAKAFUMI HAMAOKA ; TOSHIHITO KATSUMURA ; TERUICHI SHIMOMITSU
Japanese Journal of Physical Fitness and Sports Medicine 1998;47(1):103-117
A study was conducted to examine activity patterns of surface electromyograms (EMGs) in the triceps surae muscles (medial gastrocnemius, MG ; lateral gastrocnemius, LG ; soleus, SOL) during isometric contraction in plantar flexion (60% MVC, 20% MVC) after immersion in water at three different temperatures. Seven healthy male subjects were immersed in water at 2-3°C (ICE), 19-21°C (MID), and 40-42°C (HOT) . The results of the study are summarized as follows :
1) In the MG and LG, there was a slight increase in the rate of integrated electromyograms (IEMGs) in the MG (the main agonist muscle) . However, the rate of increase in the LG, which is the synergistic muscle, was much greater than that in the MG when contraction was sustained at 60% MVC. Therefore, the activity pattern suggests that muscle activity in the LG compensates for that in the MG.
2) The IEMGs of the SQL with sustained contraction, increased significantly after immersion in HOT and MID, but the IEMGs decreased after immersion in ICE. These results suggest that the recruitment threshold in slow-type motor units should increase during sustained isometric contrac-tion in ICE.
As illustrated above, the activity of the LG increased to compensate for that of MG. In the SQL, muscle activity with sustained contraction decreased in ICE. These results suggest that control mechanisms of the central nervous system might play an important role in the associated movement of the triceps surae muscles.
5.Establishment of a new function for pharmacies : sharing of patient-monitored warfarin PT-INR information with clinics
Keiko Yamamura ; Hiroyuki Kurata ; Katsuro Shigeno ; Takashi Osada ; Yuzo Adachi ; Yoshiya Hasegawa
An Official Journal of the Japan Primary Care Association 2012;35(1):45-48
Objective : To provide efficient medical care to patients taking warfarin by developing a system for sharing prothrombin time-international normalized ratio (PT-INR) monitoring data between clinic and pharmacy ; and to verify the functionality of this system.
Methods : Before a clinic appointment, patients visited a pharmacy to self-monitor PT-INR levels with the rapid measuring device Coagucheck. Pharmacists noted the following on a form shared between the clinic and the pharmacy : 1) compliance, 2) side effects, 3) diet, and 4) PT-INR. On the basis of this information, they noted their opinions on the appropriate warfarin dose. Each patient submitted the form to the clinic doctor, who then prescribed warfarin on the basis of the information recorded. After the consultation, the patient took this prescription to the pharmacy to obtain the required medication, and received from the pharmacist the dosage information based on the doctor's instructions. Thus, the sequence of the patient's visits was pharmacy-clinic-pharmacy.
Results : From one pharmacist's report, it was apparent that one patient whose PT-INR level was outside the target range was occasionally skipping a warfarin dose because of a misunderstanding about the treatment. The pharmacist recorded the patient's information on the form to inform the doctor. After consultation with the doctor, the pharmacist gave a detailed explanation on the purpose of taking warfarin. As a result, patient compliance improved and the PT-INR reached the target level after one month.
Discussion : Development of this system revealed that patients can receive appropriate warfarin treatment when information on PT-INR becomes available during clinical consultation and compliance is achieved. The system for sharing the patient's self-monitored PT-INR data between clinic and pharmacy is considered beneficial for the patient.
6.Creating a List of Oral Anticancer Drugs using the Simple Suspension Method for Appropriate Therapy
Manabu Amano ; Hiroyuki Hichiya ; Chimi An ; Yoshifumi Kiyohara ; Yoshito Zamami ; Mamoru Seto ; Tetsuo Inoue ; Kazuho Tanaka ; Naomi Kurata ; Fusao Komada
Japanese Journal of Social Pharmacy 2013;32(2):43-47
In cancer chemotherapy, it is very important to take into account the patient’s background. In recent years, a simple suspension method has attracted increased attention as a method that prevents changes in the stability and safety of various drugs. However, of 135 oral anticancer drugs, only 28 have been examined using this method, as of April 2013. In this study, we carefully investigated whether 53 oral anticancer drugs could be adapted to the simple suspension method, except for the 28 drugs that had already been previously reported. The results showed that most of these oral anticancer drugs could be adapted to the simple suspension method. Of seven drugs that were not adapted, six were generic drugs. In addition, it was clear that the evaluation of bicalutamide tablets was significantly different from our expected results. In conclusion, we were able to qualitatively assess all 53 oral anticancer drugs. This is equivalent to half of 107 untested drugs. These results provide useful information to cancer patients using oral anticancer drugs prepared using the simple suspension method.
7.iLBE for Computational Identification of Linear B-cell Epitopes by Integrating Sequence and Evolutionary Features
Hasan MD.MEHEDI ; Khatun MST.SHAMIMA ; Kurata HIROYUKI
Genomics, Proteomics & Bioinformatics 2020;18(5):593-600
Linear B-cell epitopes are critically important for immunological applications, such as vaccine design, immunodiagnostic test, and antibody production, as well as disease diagnosis and therapy. The accurate identification of linear B-cell epitopes remains challenging despite several dec-ades of research. In this work, we have developed a novel predictor, Identification of Linear B-cell Epitope (iLBE), by integrating evolutionary and sequence-based features. The successive feature vectors were optimized by a Wilcoxon-rank sum test. Then the random forest (RF) algorithm using the optimal consecutive feature vectors was applied to predict linear B-cell epitopes. We combined the RF scores by the logistic regression to enhance the prediction accuracy. iLBE yielded an area under curve score of 0.809 on the training dataset and outperformed other prediction models on a comprehensive independent dataset. iLBE is a powerful computational tool to identify the linear B-cell epitopes and would help to develop penetrating diagnostic tests. A web application with curated datasets for iLBE is freely accessible at http://kurata14.bio.kyutech.ac.jp/iLBE/.
8.Examination Regarding the Simple Suspension Method using Oral Anticancer Drugs
Masahiro Murakami ; Yoshihiko Ikemoto ; Narumi Toya ; Mihi Paku ; Miyuki Okuyama ; Kazuko Hatakeyama ; Satoko Katsuragi ; Masako Ohno ; Hiroyuki Hichiya ; Yoshito Zamami ; Chikaaki Muro ; Takeshi Kimura ; Naomi Kurata ; Manabu Amano
Japanese Journal of Social Pharmacy 2016;35(1):34-37
To administer oral anticancer drugs safely, the simple suspension method has been introduced in many hospitals. Therefore, concerning drugs for which it is unclear whether or not this method is applicable, testing must be able to be conducted at any time. In this study, we investigated 20 oral anticancer drugs to expand information on the application of the simple suspension method. Disintegration/suspension and permeability tests were conducted, as described in the 3rd version of the Tube Administration Handbook for Oral Drugs. All products were disintegrated/suspended after 10 minutes. On permeability tests, there was no residue in any tube for tubal feeding. On the final evaluation, the products were regarded as suitable (grade 1). Bicalutamide tablets (80 mg, TCK and KN), which were analyzed in this study, were regarded as suitable (grade 1) on the final evaluation. On the other hand, the simple suspension method is not applicable for a brand-name drug, Casodex® tablets (80 mg). This may be related to the different additives. Furthermore, the results suggest that, even when the simple suspension method is not applicable for a brand-name drug, it may become applicable for generic drugs. This may provide a new merit for promoting the use of generic drugs.