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Biomedical subjects

T Fukunaga

Publications and source records attributed to T Fukunaga.

At least 163 records · Page 9Linked to original sources

Influence of two different modes of resistance training in female subjects.

In resistance training, it has been empirically accepted that muscle hypertrophy is developed by low intensity and high volume training, while muscle strength and power are developed by high intensity and low volume training. The purpose of the present study was to investigate the influence of two different modes of resistance training on isokinetic strength and muscle cross-sectional area (CSA) in females. Eleven females, who had no experience in resistance training, participated in this study and were randomly divided into two groups. The former consisted of 4-5 sets of 15-20 RM (repetition maximum) with sufficient rest between sets (Group H), while the latter consisted of 8-9 sets of 4-6R M with 90 s of rest between sets (Group S). The former was assumed to be appropriate for muscle hypertrophy and the latter muscle strength, respectively. All subjects completed isotonic knee extension exercise three times a week for 8 weeks. Measurements were made on quadriceps muscle cross-sectional area (CSA) and isokinetic torques at 0, 60, 180, and approximately 300 degrees before training, at the fifth week and the end of training period. Muscle CSA was defined as the sum of CSA measured at 30, 50 and 70% of femur length. After training, muscle CSA had significantly increased in both groups: 3.3 +/- 0.7% (p < .05) for group H and 3.6 +/- 1.1% (p < .05) for group S, respectively. While the changes in isokinetic torque were 43.4 +/- 47.5% (p < .05) for group H and 27.4 +/- 31.3% (p < .05) for group S, respectively. In both groups the percentage changes of the isokinetic strength were significantly higher than those of the CSA. No significant difference in these variables were found between the two groups. These results suggest that during the early phase of resistance training two different modes of resistance training may have similar effects on muscle CSA and isokinetic strength in untrained females.

Adult↗

The effect of ethanol or hepatotoxin exposure on rat transferrin desialylation.

Serum carbohydrate-deficient transferrin (CDT) is being increasingly used as a biological indicator for excessive alcohol consumption. However, the mechanisms behind the changes in the carbohydrate moiety of transferrin are unclear, although they have been suggested to be mediated by acetaldehyde or liver damage. To study this, an animal model involving alterations in serum isotransferrin concentrations would be needed. The present work examined the changes in the carbohydrate moiety of transferrin in rats after different degrees of ethanol exposure, the effects of chronically elevated acetaldehyde levels, and also the changes, produced with liver toxins (galactosamine) and carbon tetrachloride). Ethanol was administered both in the drinking fluid and by intubation, reaching a dose of 11 g/kg/day over 7 weeks, or 16 g/kg/day over 4 weeks. Serum samples from rats maintained on high ethanol for 10 weeks by intragastric infusion were also analysed. Some rats simultaneously had cyanamide administered to elevate acetaldehyde levels. However, neither ethanol nor acetaldehyde had any effect on transferrin. Intraperitoneal galactosamine, but not carbon tetrachloride, induced transferrin desialylation. Thus, in the rat, neither chronic ethanol consumption nor elevated acetaldehyde induces changes in transferrin microheterogeneity.

Acetaldehyde↗

Total and segmental subcutaneous adipose tissue volume measured by ultrasound.

Total and segmental subcutaneous adipose tissue volumes (SATV) were estimated and compared in 13 healthy young women with a mean age of 21.4 yr. Total and segmental (head and neck, forearm, upper arm, trunk, thigh, and lower leg) SATV were estimated from subcutaneous adipose tissue layer thickness and the body surface area; the former by B-mode ultrasound and the latter by direct measurement. Consecutive magnetic resonance images (MRI) were obtained from head to toe (10 mm thickness), from which adipose tissue areas as well as total and regional SATV were determined. SATV of the upper arm and thigh estimated by ultrasound was significantly lower compared to that of MRI-measured SATV; however, there were no significant differences found in the other four segments. As a result, total estimated SATV obtained was on average 5.5% lower with ultrasound than with MRI-measured total SATV; however, there were no statistically significant differences between the two values. Significant strong correlations were observed between MRI-measured total and segmental SATV, and SATV estimated by ultrasound (r = 0.79-0.95) for all segments except head and neck. These results show the effectiveness of the ultrasound method for estimating SATV; however, the quantitative analysis tissue volumes would require correction.

Adipose Tissue↗

Molecular epidemiology of Japanese encephalitis virus in Okinawa.

In order to elucidate the molecular characteristics of Japanese encephalitis (JE) virus in Okinawa, 23 strains of JE virus isolated in a 25-year span were sequenced for the 240 nucleotides of the C-preM junction region and 111 nucleotides of the E gene region and compared with those of reference strains isolated in mainland Japan. The results of phylogenic analysis showed that although all the Okinawan isolates showed more than 96% homology in the nucleotide sequence in each region, they were chronologically divided into two groups: the old group (nine strains) and a new group (14 strains). On the other hand, in a comparison with reference strains in mainland Japan, the Okinawan isolates showed more than 94% nucleotide sequence homology in both regions, indicating that the Okinawan strains belong to the same genotype as that of JE strains in mainland Japan. The nucleotide homology of the old group was relatively higher than that of the new group. Among the 14 strains in the new group, 13 strains were isolated from mosquitoes collected from a pig farm from 1986 through 1992. These strains showed higher nucleotide divergence than the old group strains, isolated from mosquitoes and swine sera collected at several sites, in both regions. A nucleotide substitution at the position 1920 in the E gene was identified in three isolates. This substitution generated an aspargine-proline-threonine sequence capable of serving as an attachment site of carbohydrate.

Animals↗

Evaluation of angiogenic inhibitors with an in vivo quantitative angiogenesis method using agarose microencapsulation and mouse hemoglobin enzyme-linked immunosorbent assay.

In the present work, using a previously reported in vivo quantitative tumor-angiogenesis model, we attempted to ascertain whether this animal model is suitable for practical use in monitoring inhibitors of tumor angiogenesis. Mouse sarcoma-180 cells, human A431 cells or rat C6 cells microencapsulated in agarose beads were implanted s.c. into C57BL/6 mice. The level of blood vessel induction at the agarose pellet site was evaluated using mouse hemoglobin enzyme-linked immunosorbent assay on day 10 after implantation. Hydrocortisone, tetrahydro-S, medroxyprogesterone acetate, pentosan polysulfate and suramin inhibited blood vessel growth in our in vivo tumor-angiogenesis assay system, and heparin enhanced the antiangiogenic effects of hydrocortisone and tetrahydro-S. These results are almost entirely consistent with those observed in common assay systems, and suggest that this method may be useful for the identification and quantitative evaluation of inhibitors of tumor angiogenesis.

Animals↗

Estrogen-related acetaldehyde elevation in women during alcohol intoxication.

Alcohol is more often unpleasant and causes tissue damage more rapidly in women than men. The present study was designed to find out whether acetaldehyde, the primary metabolite of alcohol, could play a crucial role in these actions. Special emphasis was focused on the appropriate determination of blood acetaldehyde and hormonal factors. Occurrence of elevated blood acetaldehyde levels during alcohol oxidation was established in both normally cycling women and ones taking oral contraceptives, but not in men. An association between elevated acetaldehyde levels and high estrogen phases was observed in both groups of women. Estrogen-related acetaldehyde elevation is suggested to be the key factor explaining the gender differences of the adverse effects of alcohol.

Acetaldehyde↗

Subcutaneous and visceral fat distribution and daily physical activity: comparison between young and middle aged women.

OBJECTIVE: To examine the effects of aging and physical activity on distribution patterns in subcutaneous and visceral fat. METHODS: Distributions of subcutaneous rat mass at six segments (face and neck, forearm, upper arm, trunk, thigh, and lower leg) were determined by adipose tissue thickness measurements by B mode ultrasonogram and body surface areas. Visceral fat mass was calculated by subtracting subcutaneous fat mass from the total fat mass determined hydrodensitometrically. Measurements were made on young and middle aged, trained and sedentary women (four groups). RESULTS: Per cent body fat was lower in trained than in sedentary individuals, both in the young and the middle aged subjects. The distribution of subcutaneous fat mass differed between sedentary and trained women. Trained young women had a reduced subcutaneous fat mass compared to sedentary young subjects in all segments except face and neck; the disparity between middle aged sedentary and trained women was limited to upper arm and trunk (P < 0.01 each), with no significant difference in face and neck, forearm, and lower limb segments. Differences in visceral fat mass between sedentary and trained subjects were similar for young and middle aged women (young, 2.5 v 3.7 kg; middle aged, 4.0 v 6.5 kg). CONCLUSIONS: Women who exercise regularly appear to accumulate less adipose tissue, especially in upper arm and trunk segments as they get older, with visceral fat mass remaining lower than in sedentary individuals.

Adipose Tissue↗

Specific tension of human plantar flexors and dorsiflexors.

Reported specific tension measurements for human skeletal muscle vary widely. This variability could be due, at least in part, to the determination of the physiological cross-sectional area (PCSA) of the muscles. In the present study, serial magnetic resonance images were taken every 10 mm along the lower leg of 8 male subjects to calculate the volume and subsequently the PCSAs of the individual muscles producing plantar flexor and dorsiflexor torques. Maximum plantar flexor and dorsiflexor voluntary isometric torques were determined at ankle joint angles of 90, 100, 110, and 120 degrees. Peak tendon force estimated from torque and moment arm measurements was more than fourfold higher in the plantar flexors (3,623 +/- 136 N) than in the dorsiflexors (832 +/- 19 N). PCSAs were about eight- and threefold higher than the anatomic cross-sectional areas at the level of maximum girth of the calf for the plantar flexor and dorsiflexor groups, respectively. Mean muscle volume and PCSA were 4.6 and 12 times larger in the plantar flexors compared with the dorsiflexors, respectively. The PCSAs of both plantar flexors (r = 0.92) and dorsiflexors (r = 0.80) were highly correlated with the tendon tension of the respective muscle groups. The maximum specific tension was more than twofold higher in dorsiflexors than in plantar flexors. These data suggest that factors other than PCSA contribute to the force output potential of ankle plantar flexors and dorsiflexors in humans.

Adult↗

Tendinous movement of a human muscle during voluntary contractions determined by real-time ultrasonography.

The degree of shortening or lengthening of muscles during joint actions has not been clarified in humans, although such information is essential in understanding human muscle functions. In this study, the tendinous movement of a muscle was determined by real-time ultrasonography during voluntary contractions. The tibialis anterior muscle (TA) was tested in five healthy men who performed dorsi- and plantar flexion movements (shortening and lengthening of TA) at two frequencies (0.1 and 1.5 Hz). The insertion point (eta) of fascicles onto the aponeurosis was clearly visualized on the ultrasonogram, and its position relative to a fixed marker moved proximally and distally according to dorsi- and plantar flexion of ankle joint. The movement of eta occurred in phase with the angular change of ankle joint, giving high correlations (r = 0.93 to 0.97) between the displacement of eta and the angle. The displacement of eta for one radian of joint angle change, 46.5 +/- 1.7 (SD) mm, was comparable to the reported moment arm of TA. The present method has many potential applications in the field of muscle physiology and biomechanics in humans.

Adult↗

Acid lipase inhibitor in chicken plasma identified as apolipoprotein A-I.

We have reported a inhibitor of acid lipases in liver lysosomes and erythrocytes from chickens [M. Fujii et al., Int. J. Biochem., 22, 895-898 (1990)]. In this paper, the properties of the inhibitor were described in comparison with those of apo A-I of chicken. The purified inhibitor migrated with the same mobility on SDS-PAGE as apo A-I, and had a molecular weight of 27,000. The peptide map from the lipase inhibitor was similar to that of apo A-I. Antibodies to the acid lipase inhibitor also reacted with apo A-I. Apo A-I inhibited the acid lipase activities of liver lysosomes and erythrocytes from chickens as strongly as the lipase inhibitor. The N-terminal amino acid sequence of lipase inhibitor was identical to that of apo A-I as far as residue 20. The amino acid sequence of peptides obtained from the inhibitor by cleavage with CNBr corresponded to internal sequence of apo A-I, and so the CNBr-peptides were derived by cleavage after the methionine residues in apo A-I. The findings showed that the inhibitor of the acid lipases in liver lysosomes and erythrocytes from chickens was identical to apo A-I.

Amino Acid Sequence↗

Visceral leishmaniasis misdiagnosed as malignant lymphoma.

Visceral leishmaniasis is a chronic infectious disease caused by a protozoan parasite of the genus Leishmania, characterized by intermittent fever, monocytosis, hepatosplenomegaly and hypergammaglobulinemia. This morbid condition is rather difficult to diagnose correctly, especially at its early stage, because it is rarely encountered in Japan. Recently we treated a case of visceral leishmaniasis in which the patient was misdiagnosed as malignant lymphoma, and went through splenectomy and steroid administration, which made the diagnosis more difficult.

Adult↗

Immunosuppressive effect of tacrolimus (FK-506). Bone xenografts in rabbits.

We examined the immunomodulatory effect of the macrolide antibiotic FK-506 (tacrolimus) in bone xenograft transplantation. Full-thickness pieces of iliac bone from mongrel dogs were transplanted into the iliac bone of Japanese white rabbits. FK-506 at a dose of 1.6 mg/kg/day was injected into the rabbits for 10 days after transplantation. In the animals treated with FK-506, inflammatory cell infiltration was remarkably reduced and revascularization accompanied by new bone formation occurred in the grafts. At 4 months after the transplantation, the formation of new bone and of mature new bone marrow were observed. In a control group, inflammatory cell infiltration was marked around the graft from 2 weeks after the transplantation. Revascularization from the recipient site to the graft in the control group was poor and only a small amount of new bone had formed at 4 months. Our findings suggest that short-term administration of FK-506 has a beneficial effect on experimental xenograft bone transplantation.

Animals↗

[Shotshell injuries--single or multiple shots?--a case report].

The case of a 64-year-old hunter who was accidentally shot at a distance of 40 meters with a shotgun by a member of hunting group was reported. At the scene, the victim was found dead and showed two bullet wounds in the left lateral chest and thigh, and a penetrated wound in the left knee. Autopsy findings revealed that the former two wounds were discharged from the left side of the body, and the last one in the knee from the right. The assailant and comrades who happened to be on the scene of the accident deposed that the only one shot sound was heard at that time. Whether quite different directions of these three wound tracks could be explained with single shot or multiple ones, we discussed the locus of the bullets in consideration of the posture of the victim.

Forensic Medicine↗

[Reversal of portal-systemic encephalopathy by shunt-preserving disconnection of portal and systemic circulation].

Obliteration of portal-systemic shunts surgically or by interventional radiological techniques is fairly effective in reversing intractable portal-systemic encephalopathy (PSE), but is often associated with ascites accumulation and/or formation of esophageal varices. This study reports four patients with incapacitating PSE who were treated by interventional radiological techniques via percutaneous transhepatic route. One case had the shunt embolized directly. In the other three the blockage was placed on the proximal part of the splenic vein, whereby disconnecting the mesenteric-portal blood flow from the systemic circulation while preserving the shunt. The patient of shunt closure showed transient correction of encephalopathy, but developed massive ascites and esophageal varices, encephalopathy recurred, resulting in death from hepatic failure two months after the procedure. In the cases of shunt-preserving disconnection of portal and systemic circulation (SPDPS) immediate and permanent clearing of encephalopathy was achieved without manifestation of ascites or esophageal varices during the follow-up period of 10 to 31 months. The difference of portal pressure between before and after the procedure was 18 mmHg in the shunt-closed patient and 3 mmHg in SPDPS group. We conclude from this limited experience that SPDPS can be an effective and safe method in treating PSE in adequately selected patients.

Aged↗

Validity of a random noise oscillation and body box system for the measurement of the respiratory impedance of small animals.

The accuracy and validity of a body box system which was developed for the measurement of airway and chest wall impedance in small animals such as canines was evaluated. Input impedance was calibrated using a resistance tube and the mouth flow sensing system was designed to be as symmetrical as possible such that the minimal common mode rejection ratio (CMRR) from 10 to 40 Hz was greater than 60 dB. The validity of this system using the resistance tube and inertant models indicated that the average error ratio for the input impedance and for the flow transfer function between the mouth and chest flow was within 3 and 0.5%, respectively. The location of the box pressure port near to the oscillatory flow inlet was shown to potentially give rise to errors in the measurement of the flow transfer factor due to the direct effects of the inflow. A distance of 60 cm was adopted in the present system, which proved to be sufficient to avoid this effect. It was concluded that the body box system which is described for small animals in the present study is appropriate for obtaining separate and accurate airway and tissue impedance data.

Airway Resistance↗