Muscle fibre number following hindlimb immobilization.
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Biomedical subjects
Publications and source records attributed to S Katsuta.
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A method for highly dose-localized irradiation using a linear accelerator (linac) for a brain tumor has been developed. The method requires a linac, a computed tomography (CT) system, a CT simulator, and a treatment planning system for radiotherapy, with which most major radiotherapy centers are equipped. To immobilize a patient during irradiation, a custom-made device made of synthetic material which became flexible with heating was used. With the CT system and the CT simulator the target was identified and geometrical data for positioning the tumor at a point to which x-ray beams were directed (an isocenter of the linac) were obtained. By rotating a treatment couch it was made possible for the x-ray source to rotate around the isocenter on multiple planes. Dose distribution obtained with this method was compared to that of the gamma unit and found comparable. Since the method requires no invasive procedure, it appears suitable for treatment, with fractionated irradiation, of malignant tumors.
The alteration ratio of lung field CT numbers in different respiratory phases was studied in 52 patients with chronic pulmonary obstructive disease (COPD) and 20 subjects with normal lung. The 52 patients with COPD consisted of 30 with clinically diagnosed chronic pulmonary emphysema (CPE), 15 with suspected CPE (sCPE) and seven with bronchial asthma (BA). The 20 subjects with normal lung were divided into two groups according to age. CT images were obtained in each case under different respiratory conditions, i.e., full inspiration and end expiration. The following parameters were employed for numerical evaluation: %(I-E)Apex = (MLDApexI-MLDApexE/MLDApexE x 100 %(I-E)Mid = (MLDMidI-MLDMidE)/MLDMidE x 100 %(I-E)Base = (MLDBaseI-MLDBaseE)/MLDBaseE x 100 %(I-E)Whole = (MLDWholeI-MLDWholeE)/MLDWholeE x 100 where MLD is mean lung density and the letters I and E stand for full inspiration and end expiration, respectively. The small letters Apex, Mid, Base and Whole stand for apex cut, mid-thorax cut, base cut and whole lung, respectively. The values of %(I-E)Whole were significantly different between disease groups except for those between the sCPE and BA groups. The values of %(I-E)Whole showed a good positive correlation with FEV1.0% (r = 0.79) and V25/H (r = 0.80) and a good negative correlation RV/TLC (r = -0.75). Diagnostic differentiation of COPDs by %(I-E)Whole values identified 80% of CPE cases and 91% of normal lung cases. In the sCPE group, the values of %DLco in patients with %(I-E)Whole above 9% were smaller than those in patients with %(I-E)Whole under 9%.(ABSTRACT TRUNCATED AT 250 WORDS)
Twenty 4-week-old Wistar rats exercised voluntarily in running wheels each day for 45 days. Fibre type composition, fibre cross-sectional area and the number of capillaries around a fibre of the slow-twitch soleus and fast-twitch plantaris muscles were examined and compared with animals which had no access to running wheels. The exercise group had a higher percentage of fast-twitch oxidative glycolytic (FOG) fibres and a lower percentage of fast-twitch glycolytic (FG) fibres in the deep portion of the plantaris muscle. The area of FOG fibres in the surface portion of the plantaris muscle was also greater in the exercise group. In the exercised animals, there was a positive relationship between the running distance and the area of FOG fibres in both the deep and surface portions of the plantaris muscle. In addition, the running distance correlated positively with the percentage of FOG fibres and negatively with that of FG fibres in the deep portion of the plantaris muscle. There were no relationships between the running distance and fibre type composition, or fibre area and capillary supply in the soleus muscle. These results suggested that the increase in the percentage and area of FOG fibres in the fast-twitch muscle was closely related to voluntary running.
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The effect of muscle hypertrophy on the relationship between magnetic resonance (MR) relaxation time and muscle fibre composition was investigated. Relaxation time and muscle fibre composition were measured in five subjects before and after a 20-week period of strength training. Muscle fibre composition in all subjects exhibited a significant shift to a predominance of fast-twitch (FT) fibres as a result of 20-week strength training (% area FT fibres: mean values from 49.8%, SD 17.9% to 57%, SD 5.6%; P less than 0.05). Longitudinal relaxation time (T1) and transverse relaxation time (T2) were prolonged significantly after strength training (T1 mean values from 334.9 ms, SD 13.6 to 359.0 ms, SD 9.0, P less than 0.001; T2 from 27.5 ms, SD 0.9 to 30.8 ms, SD 2.3, P less than 0.05). A constant relationship was observed in changes caused by strength training in muscle fibre composition (% area FT) and relaxation time, with a high correlation obtained between both parameters. These results indicate that MR relaxation time can be used for non-invasive estimation of muscle fibre composition.
Histochemical and biochemical analyses were performed in order to examine the relationship between myosin light-chain (LC) isoforms and fibre-type distributions in whole human skeletal muscle. Muscle biopsies were obtained from the vastus lateralis muscle in six healthy men, and analysed for the relative area occupied by each fibre type (percentage of fibre type area) and the molar ratio of each LC isoform. The percentage of type I fibre area was positively correlated with the molar ratio of slow LC (LC1s and LC2s) to total LC. The regression line was located below the line of unity. Also, the ratio of percentage of type IIa fibre area to that of type II fibre area was positively correlated with the molar ratio of the fast alkali LC LC1f to fast alkali LCs LC1f and LC3f. These results support previous study, having shown that in human skeletal muscle some type I fibres express various amounts of fast LC in addition to slow LC and suggest that fast myosin heavy-chain HCIIa is favourably associated with LC1f, whereas HCIIb is favourably associated with LC3f.
Magnetic resonance imaging (MRI) is superior to ultrasonography and X-CT especially in density resolution in soft tissue. 31P NMR provides information on metabolism, which has not been obtained in vivo by conventional methods, such as phosphocreatine (PCr), inorganic phosphate (Pi), ATP, and intracellular pH. We used MRI and 31P NMR spectroscopy to study skeletal muscle metabolism of human and rat. These NMR results suggested that 1) estimation of muscle fiber composition, 2) evaluation of muscle ATP turnover and 3) imaging of local muscle fatigue are possible.
A multi-institutional prospective study for the analysis of prognostic factors for patients with osseous metastasis was performed. From February 1986 through June 1988, a total of 216 patients were included in this study. Cox's regression model made it clear that the most significant overall prognostic factor was primary site (p = 0.0002). In the lung cancer group, performance status (p = 0.0036) and metastasis of organs than bone (p = 0.0105) were also significant prognostic factors. In the breast cancer group, no significant factors were obtained. In the hepatoma group, the values for alkaline phosphatase (ALP) (p = 0.0021), lactate dehydrogenase (LDH) (p = 0.0195), and sex (p = 0.0264) proved significant. In the group of other cases, the most significant prognostic factor was the value for urinary hydroxyproline/creatinine ratio (p = 0.0001), followed by the pain score of RTOG (p = 0.0018). These factors and actual survival periods obtained in this study will be useful for the future stratification of patients for individualized optimal radiation schedules.
The purpose of this study was to test the hypothesis that older persons can minimize the reduction in physical fitness with aging if they start training before approximately 50 years of age, beyond which strength decline has been reported to become more pronounced. Maximal values for isometric strength, dynamic strength and speed of movement of the biceps brachii and quadriceps muscles, back-lift strength, and predicted oxygen uptake (VO2max = VO2max) were measured in 39 male subjects who were 60-68 years old. Four groups were studied: T26, T45, T56, and untrained. The T26 group had been training (jogging 10 km.day-1, 5 days.wk-1 at 10 km.h-1) since before their mid-thirties (mean 26 years), the T45 group since their forties (mean 45 years), the T56 group since their fifties (mean 56 years), and the untrained group had never taken part in any systematic training. Collectively, the T26 and T45 groups had significantly (p less than 0.05) higher values for muscle strength, speed of contraction, and VO2max than the T56 and/or untrained group(s). However, no differences were observed between the T26 and T45 groups. The results support a relation between the starting age of training and the age-dependent decline of physical fitness. Thus, the hypothesis is accepted.
CT-functional images (CT-FI's) were created from Xe-dynamic CT data of 10 patients with chronic pulmonary emphysema and 6 volunteers with normal lung. In CT-FI's of normal lungs, the values of washin and washout parameter of outer zone were larger than those of inner zone. In CT-FI's of chronic pulmonary emphysema, the values of washin parameter of inner zone were larger than those of outer zone and the value of washout parameter of outer zone were larger than those of inner zone. CT-FI's proved to helpful in evaluating the axial distribution of ventilation dynamics in chronic pulmonary emphysema.
A prospective randomized study for the analysis of optimal schedule for the patients with bone metastases was performed. From February 1986 through January 1987, a total of 131 patients entered on this trial. The data from 129 patients out of 131 were available for the analysis of prognostic factors by Cox's regression model. As a whole, it was clear that first significant prognostic factor was urinary hydroxyproline/creatinine ratio (p = 0.0001), second primary site (p = 0.0001), third pain score (p = 0.0005) and fourth other organ metastasis except bone (p = 0.0006). In the group of lung cancer, first significant prognostic factor was urinary hydroxyproline/creatinine ratio (p = 0.0007), second multiplicity of bone metastasis (p = 0.0113), and third pain score (p = 0.0270).
A 64-year-old woman of bilateral renal angiomyolipomas with spontaneous rupture, not associated with tuberous sclerosis was reported. Superselective embolization for tumors using ethanol was successfully performed, preserving normal renal function. Transcatheter embolization was considered the treatment of first choice for the urgent circumstances with spontaneous rupture.
Interleukin-1 (IL-1) inducing activity of a streptococcal preparation OK-432 and its fractions by monocytes were investigated in patients with lung cancer and healthy subjects. The results showed that cell free extracts and cell wall fractions of OK-432 were the strong IL-1 inducing fractions. IL-1 activity released by OK-432-stimulated monocytes of patients with lung cancer fell within normal range. OK-432 stimulated intracellular IL-1 synthesis as well as extracellular release by monocytes. These results, therefore, suggested that OK-432 immunotherapy in patients with malignant diseases might be effective by increasing IL-1 production of monocytes.
A distinct syndrome in infantile hemangioendothelioma consist of high-output congestive heart failure, hepatomegaly and cutaneous hemangiomas. Early therapy aimed at reduction of the shunt is essential if life is to be saved once cardiac failure becomes manifest. We report a case of infantile hemangioendothelioma with massive A-V and P-V shunt successfully treated by transcatheter embolization.
This study was undertaken to examine the blastogenic responses of PBL to Streptococcal preparation OK-432 and its fractions. The results showed that OK-432 and its fractions, Su-PR and PM, have the mitogenic activity against human lymphocytes. The demonstration that PBL which had been cultured with OK-432 expressed IL-2 receptors and the blastogenic responses of PBL to OK-432 were inhibited by anti-IL-2 antibody suggested that IL-2 and IL-2 receptors might play a central role in OK-432-induced proliferation of human lymphocytes.
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Our purpose was to test the significance of exhaustive training in aerobic or endurance capacity. The extent of adaptations to endurance training was evaluated by assessing the increase in physical performance capability and oxidative markers in the organs of rats trained by various exercise programs. Rats were trained by treadmill running 5 days.week-1 at 30 m.min-1 for 8 weeks by one of three protocols: T1-60 min.day-1; T2-120 min.day-1; and T3-120 min.day-1 (3 days.week-1) and to exhaustion (2 days.week-1). Groups T2 and T3 ran for longer than T1 in an endurance exercise test (P less than 0.05), in which the animals ran at 30 m.min-1 to exhaustion; no difference was observed between groups T2 and T3. All 3 trained groups showed a similar increase (20-27%) in the fast-twitch oxidative-glycolytic (FOG) fibers with a concomitant decrease in the fast-twitch glycolytic (FG) fiber population in gastrocnemius (p less than 0.05). The capillary supply in gastrocnemius increased with the duration of exercise (p less than 0.05): no difference was found between groups T2 and T3. Likewise, no distinction was seen between groups T2 and T3 in the increase in succinate dehydrogenase activity in gastrocnemius and the heart. These results suggest that the maximal adaptive response to endurance training does not require daily exhaustive exercise.