PubMed HealthSearch

Biomedical subjects

T Fukunaga

Publications and source records attributed to T Fukunaga.

At least 19 recordsLinked to original sources

Physiological cross-sectional area of human leg muscles based on magnetic resonance imaging.

Magnetic resonance imaging techniques were used to determine the physiological cross-sectional areas (PCSAs) of the major muscles or muscle groups of the lower leg. For 12 healthy subjects, the boundaries of each muscle or muscle group were digitized from images taken at 1-cm intervals along the length of the leg. Muscle volumes were calculated from the summation of each anatomical CSA (ACSA) and the distance between each section. Muscle length was determined as the distance between the most proximal and distal images in which the muscle was visible. The PCSA of each muscle was calculated as muscle volume times the cosine of the angle of fiber pinnation divided by fiber length, where published fiber length:muscle length ratios were used to estimate fiber lengths. The mean volumes of the major plantarflexors were 489, 245, and 140 cm3 for the soleus and medial (MG) and lateral (LG) heads of the gastrocnemius. The mean PCSA of the soleus was 230 cm2, about three and eight times larger than the MG (68 cm2) and LG (28 cm2), respectively. These PCSA values were eight (soleus), four (MG), and three (LG) times larger than their respective maximum ACSA. The major dorsiflexor, the tibialis anterior (TA), had a muscle volume of 143 cm2, a PCSA of 19 cm2, and an ACSA of 9 cm2. With the exception of the soleus, the mean fiber length of all subjects was closely related to muscle volume across muscles. The soleus fibers were unusually short relative to the muscle volume, thus potentiating its force potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Reliability of measurement of oxygen uptake by a portable telemetric system.

The purpose of the present study was to check the reliability of measurements of oxygen uptake (VO2) using a newly developed portable telemetry system. This system (K2) consisted of a face mask, a flow meter, a gas analyser with a transmitter, and a receiver. The total mass for the subject to carry was about 850 g. Three experiments were carried out, firstly to check the reliability and reproducibility of the flow meter and the K2 gas analyser, secondly to check the accuracy of K2 by comparing it with the Douglas bag method (DB), and thirdly to apply K2 to sports activities. In the first experiment, the flow meter was highly accurate up to 180 l.min-1 with good reproducibility. The measurement error of the gas analyser was less than 2%. In the second experiment, there was no significant difference in the calculated ventilation between K2 and DB. The VO2 showed no significant difference between K2 and DB with some exceptions. In the third experiment, we succeeded in the measurement of VO2 during rowing on water. The measurement of VO2 during running and playing soccer was also possible. It would seem that the present system could well be a powerful tool in the field measurement of VO2 during various sports activities.

Exercise

ABH-related antigens in human male genital tract. A histochemical examination.

The localization of ABH related antigens in human male reproductive tract was examined using monoclonal antibodies and an avidin biotin complex method. No positive reaction with blood group antibodies on spermatozoa was observed in testis and ductus epididymidis apart from erythrocytes and endothelial cells. The expression of ABH and ABH related antigens in ductuli efferents testis, ductus epididymidis, seminal vesicle and prostate was complexly coded by a combination of H, Se, Le and X genes. The results obtained in this study indicate that the ABH antigens detected on spermatozoa of seminal stains are coating antigens and not inherent to the cell membrane, and the ABO, H, Se, Le and X genes are subjected to a tissue-dependent differential expression.

ABO Blood-Group System

Phase differences between chest and mouth flows in patients suffering from pulmonary disease.

The phase difference (PD) between mouth flow and chest flow during rest breathing was measured in pulmonary diseased patients using a body box and the results were compared with normal subjects. Whereas the PD increased in patients with chronic pulmonary obstructive disease (COPD) compared to normal subjects, PD was found to be normal in patients with interstitial pulmonary fibrosis (IPF) (Normal: 2.94 +/- 1.25, COPD: 11.32 +/- 4.17*, IPF: 2.62 +/- 1.67 degrees; *P < 0.01). PD correlated well with FEV1.0/VC%, PFR, RV/TLC, VTG and Ra (r: -0.759, -0.672, -0.788, 0.666, 0.606). From an in-depth analysis of the results, we suggest that the factors which increase PD in COPD patients include hyperinflation of the lung, increases in airway resistance and increases in the parallel inhomogeneity of airway resistance accompanied by an unevenness of alveolar pressures. PD was thought to be clinically useful for the evaluation of the pathological stages of COPD because it reflects the overall clinical manifestations in COPD patients.

Adult

Thymus of abused/neglected children.

Forty-six cases of child abuse/neglect autopsied during the period of 1967 to 1990 were investigated. The weight and histological findings of the thymus were compared with those of control children. In most abused and/or neglected children, the weight of the thymus decreased conspicuously. Involution correlated well to the degree and period of maltreatment. In cases without weight loss of the thymus, i.e. spasmodic abuse by a mentally deranged parent or foster parent, a short history of maltreatment was noted. On the other hand, marked involution was observed in cases of prolonged physical abuse and/or neglect. Microscopically, a decrease in the number and pyknosis of lymphocytes were observed in the involuted thymus. Atrophy of the thymus was more conspicuous in the cortex than in medulla. Immunohistochemically, CD-1a positive cells (immature thymocytes) decreased in cases with thymic involution. This involution appears to be an important index of the degree and duration of child abuse/neglect. Furthermore, thymic involution in the early stage of childhood may also be related to insufficiency of the immune system.

Age Factors

[A comparison of fat and muscle thickness in Japanese and American women].

The purpose of this study was to investigate the ethnic differences in the body composition, thickness of subcutaneous fat and muscle between Japanese and American white females. Thirty-six Japanese (aged 20-30 years) and 42 American white females (aged 20-29 years) served as subjects. Percentage of fat weight (%fat) and fat free weight (FFW) were assessed by hydrostatic weighing. Subcutaneous fat and muscle thickness were measured by using B-scan ultrasound equipment with a 5MHz transducer at eight sites: forearm, biceps, triceps, subscapular, abdomen, quadriceps, hamstrings and posterior calf. There were no significant differences in %fat between Japanese and American subjects. However, American subjects had significantly higher values in FFW compared to Japanese. The Americans showed higher muscle thickness than Japanese at every site and higher fat thickness of biceps, triceps and hamstrings compared to Japanese subjects. For fat thickness at the abdomen, however, Japanese indicated significantly higher values than American. In both Japanese and Americans, relative values of fat weight (FW) and FFW per unit of height were significantly related to each of the sum of fat and muscle thicknesses obtained from every measurement site respectively. There were no differences in fat thickness at a given FW/height between Japanese and Americans.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue

The effects of resistance training on muscle area and strength in prepubescent age.

The purpose of this study was to determine the effect of strength training in prepubescent boys and girls on muscle strength and cross-sectional area of upper arm. Subjects were ninety-nine healthy elementary school children who belonged to 1st, 3rd and 5th grades and they were assigned to two groups of training (N = 52) and control (N = 47). Training group participated in strength training program for 12 weeks which consisted of maximum sustained isometric contraction of elbow flexion for ten sec, whereas control group did not participate in special training program in this period. In orger to determine the changes due to training, cross-sectional areas of the tissues in upper arm, such as muscle, fat and bone, were measured by the ultrasonic method. Maximum isometric and isokinetic muscle strength of elbow flexion and extension were measured by means of isokinetic cybex dynamometer. In order to assess the development of physiological maturity, TW2 method was used to estimate the skeletal age in each subject by taking the hand-wrist X-ray photograph. After 12-week training period, the whole cross-sectional areas increased in both training and control groups. This increment was due to significant increases in muscle and bone area in the training group and, on the other hand, due to the increase in fat area in the control. The increment of muscle area of training group was about 50% of that derived from the study on adults (Fukunaga, T., 1978). The increment in cross-sectional area of muscle with training was significantly correlated with the skeletal age.(ABSTRACT TRUNCATED AT 250 WORDS)

Arm

Isometric and isokinetic knee joint performance in Japanese alpine ski racers.

Isometric and isokinetic (concentric and eccentric, strength of alpine skiers with different performance levels were measured. Nine national (elite, EG) and 10 collegiate (trained, TG) female alpine skiers (16 to 23 years of age) performed maximal voluntary knee extension and flexion. Peak torque was measured at an angular velocity of 30 deg.s-1. The cross-sectional area (CSA) of thigh muscles (quadriceps and hamstring muscles) was determined by an ultrasonic method. No significant differences in anthropometric variables and CSA were observed between EG and TG. EG had significantly greater (p < 0.01 for extensors and p < 0.05 for flexors) eccentric knee extensor and flexor strength than that of TG whereas no significant differences were noted in isometric and concentric strength. Eccentric strength/CSA ratio was also higher for EG than for TG. It was suggested that knee extension and flexion strength during eccentric muscle action might be related to the performance level of alpine skiers.

Adolescent

[A study on the psychological status of perioperative patients (II)].

In order to study the changes of the psychological status during perioperative period, we performed four different psychological tests, Spielberger's rating scale "The State-Trait Anxiety Inventory (STAI)", Self-rating Depression Scale (SDS), Maudsley Personality Inventory (MPI) and Baum test, in 63 patients who received simple total hysterectomy for myoma of uterus. The anxiety ratings showed a significant decrease postoperatively. On the contrary, the SDS index that expresses the level of depressive mood showed no significant change during perioperative period. Moreover the patients who had shown a tendency of nervousness in MPI kept the high level of the SDS index during perioperative period than the other patients who had not shown a tendency of nervousness in MPI. In Baum test, more than 75% of patients manifested psychologic fragility or lability. These results suggest that depressive mood affects strictly the psychological status in postoperative period more than anxiety. We presume that the depressive mood during perioperative period is responsible for the postoperative psychological disturbance.

Adult

[A case of gallbladder cancer with marked response to EAP treatment].

A case of unresectable gall bladder cancer due to multiple metastasis was dealt with EAP (VP-16, ADM, CDDP) treatment. The case was a 49-year-old male who was admitted to the hospital with a 3 cm sized umbilical tumor. After 2 cycles of the treatment, the tumor size significantly decreased and the symptoms diminished. In parallel, the symptoms from bone metastasis and dissemination also disappeared. As for tumor markers, CA 19-9 indicated 5151 U/ml, fell down to the normal range after the treatment. In this case, the efficacy of EAP treatment to the primary gall bladder carcinoma was undetectable, because of the difficulty of elucidation of the primary site by diagnostic images. However, all data suggested that EAP treatment was effective to the advanced unresectable gallbladder cancer, at least to its metastatic sites.

Adenocarcinoma

[Evaluation of gastroenterological disease by using 18F-FDG PET--differential diagnosis of malignancy from benignity].

In this study, we used 18F-FDG PET to differentiate gastroenterological malignancy from benignity. We investigated 122 patients with gastroenterological disease before treatment (with lesions exceeding 2.0 cm in diameter only). 60 min after injection of FDG, although 16 cases out of 17 benign disease did not reveal accumulation higher than normal tissue, 105 cases of malignant tumor except some of hepatocellular carcinoma revealed high accumulation of FDG. FDG uptake was expressed as the Ci/Cp ratio, calculated from radioactivity of the tumor (Ci) and the plasma (Cp). 89 cases out of 90 which show more than 2.0 of Ci/Cp ratio were malignant tumor. On the other hand, 32 cases which show less than 2.0 contained 16 cases of benign disease and 15 of hepatocellular carcinoma. FDG PET is a useful tool for differential diagnosis of malignant tumor from benign disease except some of hepatocellular carcinoma.

Deoxyglucose

Electrophoretic phenotyping of erythrocyte enzymes.

Erythrocyte acid phosphatase (EAP), esterase D (ESD) and phosphoglucomutase (PGM) phenotypes among the erythrocyte enzyme types of blood groups are surveyed and a modified cellulose acetate membrane isoelectric focusing (CAM-IEF) method for their exploration is described. The phenotyping procedures are usually classified as either equilibrium or non-equilibrium IEF. Equilibrium IEF, which is based on differences in pI values, includes three methods: (i) a narrow pH range of carrier ampholytes, (ii) a relatively narrow pH range of carrier ampholytes containing chemical separators and (iii) immobilized pH gradient gels. Among the three methods, immobilized pH gradients provides a better resolution of isozymes. Conversely, the disadvantages of immobilized pH gradients include longer focusing times and complex gel preparations. Moreover, immobilized pH gradients are unsuitable for stain analysis because of the insensitivity of PGM1 detection. A hybrid IEF system and a commercial immobilized pH gradient dry plate have overcome these problems. However, EAP typing is extremely expensive and ESD typing is not well distinguished by hybrid IEF. As each method has both merits and demerits, the most suitable technique should be selected based on the kind of erythrocyte enzyme types and sample conditions. On the other hand, non-equilibrium IEF is a rapid method because isozymes are detected on the basis of their charge differences under non-equilibrium conditions. Moreover, the appropriate addition separators increases the charge difference and provides a good resolution within a shorter time. Addition of more separators produces a narrow pH range in the gel and takes a substantially longer time to reach the optimum pH range for charge difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase

Preparation of soluble murine IL-6 receptor and anti-murine IL-6 receptor antibodies.

Starting with a previously isolated cDNA clone encoding murine IL-6R, a stable transformed Chinese hamster ovary cell line constitutively expressing soluble murine IL-6R (smIL-6R) has been established. The smIL-6R was purified to homogeneity by sequential filtration and chromatography of culture medium. The smIL-6R augmented the sensitivity of M1 cells to IL-6 in their growth inhibition in a dose-response manner. Rat hybridomas producing mAb specific to murine IL-6R were also established. One of the clones, RS13, produced IgG2a isotype that was capable of inhibiting IL-6 activity. ELISA for the quantitation of smIL-6R was established, which could detect smIL-6R in a quantity as low as 1 ng/ml.

Amino Acid Sequence

Recent status of the medical examiner system in Japan: demographic variation of medicolegal deaths in Hyogo Prefecture and uncertainty in medicolegal investigations conducted by medical practitioners.

The medical examiner system has been steadily abolished in Japan. Instead, medicolegal investigations are entrusted by the police to medical practitioners, who are not permitted to perform autopsies. The necessity for the medical examiner system was assessed through inquest records in Hyogo, one of the three prefectures which still have medical examiner systems. Standardized mortality ratios (SMRs) for accidents and suicides were negatively associated with population density, being high in rural areas with a large proportion of elderly citizens, while the SMR for natural deaths was high in urbanized areas and associated with the proportion of inquests to total resident deaths. The high proportion of inquests, however, did not always mean that inquest records were of good quality. Significant differences in the quality of medicolegal investigations seemed to exist between medical examiners and medical practitioners. That is, in order to certify the cause-of-death, medical examiners performed autopsies in about half of their cases, while only 2% of medical practitioner cases were subjected to autopsies. Medical practitioners, who certified the cause-of-death as "heart failure" without advising an autopsy, were regularly entrusted with inquests. It is likely that the causes-of-death for medicolegal cases may be questionable since more than 85% of all medicolegal deaths were investigated by medical practitioners, which may cause inaccuracy in at least 3-7% of mortality statistics. It is necessary to educate medical practitioners concerning the importance of mortality statistics and ICD and on the validity of autopsies, in order to obtain accurate mortality statistics from medicolegal cases.

Accidents

Exertional muscle injury: evaluation of concentric versus eccentric actions with serial MR imaging.

Eccentric muscular actions involve the forced lengthening or stretching of muscles and tend to produce exertional injuries. This study used magnetic resonance (MR) imaging to serially evaluate muscles in five healthy, untrained subjects who performed exhaustive biceps exercise by doing isolated eccentric and concentric actions with a dumbbell. Symptoms were assessed, and T2-weighted images of the arms were obtained before exercise and 1, 3, 5, 10, 25, 40, 50, 60, and 80 days after exercise. Statistically significant increases in T2 relaxation times indicative of muscle injury occurred on each day of MR imaging evaluation in muscles performing eccentric actions, peaking on day 3 in two subjects; day 5, two subjects; and day 10, one subject. The pattern and extent of the abnormalities on MR images were variable. Pain, soreness, and joint stiffness were present on days 1, 3, and 5 in muscles that performed eccentric actions. MR imaging showed subclinical abnormalities that lasted as long as 75 days after the disappearance of symptoms (two subjects). Muscles that performed concentric actions had no changes in T2 relaxation times and were asymptomatic throughout the study.

Adult

Frequency characteristics of airway and tissue impedances in respiratory diseases.

We measured the frequency characteristics (at 10-40 Hz) of airway (Za) and tissue (Zt) impedances in cases of chronic obstructive pulmonary disease [asthmatic bronchitis (AB), chronic pulmonary emphysema (CPE)] and interstitial pneumonitis (IP) by use of an improved random noise oscillation and body box method. The results were then compared with those obtained for normal subjects. The real part of Za was markedly elevated in patients with AB but only slightly elevated in those with CPE. To interpret these data we used an electromechanical analogue including serial inhomogeneity with shunt impedance. From this model we concluded that AB causes both the central and peripheral airway resistances to increase, while CPE brings about a rise mainly in peripheral resistance. In IP patients, only the imaginary part of Zt decreased, which might reflect the decrease in both lung and chest wall compliance. In CPE patients, but not in AB patients, the real part of Zt fell. These data were consistent with the assumption that the decrease in mass per unit volume of lung tissue and hyperinflation of the chest wall in CPE patients might lower the tissue resistances.

Adult