Biomedical subjects

M Ito

Publications and source records attributed to M Ito.

At least 289 records · Page 16Linked to original sources

PubMed2001

Roles of carbon monoxide in leukocyte and platelet dynamics in rat mesenteric during sevoflurane anesthesia.

BACKGROUND: Heme oxygenase 1 (HO-1), induced by a variety of stressors, provides endogenous carbon monoxide (CO) and bilirubin, both of which play consequential roles in organs. The current study aimed to examine whether induction of HO-1 and its by-products modulated endothelial interaction with circulating leukocytes and platelets evoked by sevoflurane anesthesia in vivo. METHODS: Rats, pretreated with or without hemin, were anesthetized with sevoflurane in 100% O2, and lungs were mechanically ventilated. Platelets labeled with carboxyfluorescein diacetate succinimidyl ester and leukocyte behavior in mesenteric venules were visualized during sevoflurane anesthesia at 1,000 frames/s using intravital ultrahigh-speed intensified fluorescence videomicroscopy. To examine the mechanisms for the effects of HO-1 on leukocyte and platelet behavior, these studies were repeated with superfusion of either CO, bilirubin, or Nomega-nitro-L-arginine methyl ester (L-NAME). RESULTS: As reported previously, the elevation of sevoflurane concentration evoked adhesive responses of leukocytes, concurrent with platelet margination and rolling. Pretreatment with hemin, a HO-1 inducer, prevented such sevoflurane-elicited changes in the microvessels. These changes were restored by zinc protoporphyrin IX, a HO inhibitor, and repressed by CO but not by bilirubin. During sevoflurane anesthesia, however, nitric oxide suppression by L-NAME deteriorated microvascular flows irrespective of the presence or absence of the HO-1 induction. CONCLUSIONS: These results indicate that endogenous CO via HO-1 induction attenuates sevoflurane-induced microvascular endothelial interactions with leukocytes and platelets, although local nitric oxide levels appear to dominate microvascular flow in situ.

Anesthesia, Inhalation↗

PubMed2001

Kinematic evaluation of atlantoaxial joint instability: an in vivo cineradiographic investigation.

Although range of motion has been considered the best parameter to quantify atlantoaxial instability, no other kinematic parameters have been determined for dynamic quantification. The objectives of this study were to investigate the kinematics of the normal and pathologic atlantoaxial joints by cineradiography and to determine the in-vivo kinematic parameters, if any, for the quantification of atlantoaxial instability. Sagittal plane motion of the atlantoaxial joints was analyzed by cineradiography in 12 healthy volunteers and 15 patients with atlantoaxial subluxation. In both flexion and extension, C1-C2 sagittal rotation and C1 translation in the sagittal plane were measured continuously to determine the time-displacement curves for both parameters. All patients with atlantoaxial subluxation and seven of the volunteers had the sigmoid pattern in their time-displacement curves in sagittal rotation. In these cases, atlantoaxial motion showed different points of the onset of rapid increase in motion in their sigmoid curves between flexion and extension. The discrepancy between these points was more significant in the patients than in the volunteers. In most of the patients who had atlantoaxial instability, subluxation occurred when the atlantoaxial joints were still in a more extended position and they were reduced when they were still in more flexed position. The discrepancy showed characteristics similar to those of the neutral zone observed during in vitro investigations, suggesting that it becomes a good indicator of in vivo atlantoaxial instability.

Adult↗

PubMed2001

Bisoprolol improves survival in rats with heart failure.

The cardioprotective effects of bisoprolol were studied in a rat model of severe heart failure induced by autoimmune myocarditis. Twenty-eight days after immunization, Lewis rats were divided into four groups: 0.1 mg/kg/day bisoprolol (Group 0.1), 1.0 mg/kg/day bisoprolol (Group 1) and 10 mg/kg/day bisoprolol (Group 10), and vehicle (0.5% methylcellulose; Group V) (all groups, n = 13). After oral administration for 1 month, heart weight, mean blood pressure, heart rate, central venous pressure, peak left ventricular pressure, left ventricular end-diastolic pressure, +/- dP/dt, and area of fibrosis were measured. Although bisoprolol reduced heart rate (399+/-11/min in Group V, 382+/-10/min in Group 0.1, 348+/-8/min in Group 1 and 302+/-9/min in Group 10) and increased survival (62% in Group V, 69% in Group 0.1, and 100% in Group 1 and Group 10) in a dose-dependent manner, this drug did not change heart weight, the area of myocardial fibrosis or hemodynamic parameters. These observations suggested that bisoprolol may improve survival independently of its effect on left ventricular function by reducing sudden death in patients with severe heart failure.

Adrenergic beta-Antagonists↗

PubMed2001

Does craniopharyngioma metastasize? Case report and review of the literature.

OBJECTIVE AND IMPORTANCE: A rare case of recurrent craniopharyngioma at an ectopic location is described. This recurrence suggested cerebrospinal fluid seeding. CLINICAL PRESENTATION: A 65-year-old man presented for follow-up of persisting visual field defect. He had undergone total resection of a suprasellar craniopharyngioma via a subfrontal approach 3 years before presentation. Recent magnetic resonance imaging scans revealed a contrast-enhancing tumor with cystic and solid components at the right temporal lobe. The primary tumor bed was intact. INTERVENTION: A temporal craniotomy was performed for total resection of the tumor. Intraoperative findings revealed that the recurrent tumor was anatomically unrelated to the previous surgical track. Histological studies of the tumor specimen demonstrated a benign craniopharyngioma. Cerebrospinal fluid spreading was suspected to be the sole route for the recurrence. CONCLUSION: The case presented here and a review of reports on remote recurrence of craniopharyngioma suggest that care is required during intraoperative handling of the tumor and that long-term follow-up should be performed even in patients whose primary tumor was resected completely.

Aged↗

PubMed2001

Reverse redistribution of 99m Tc-sestamibi after direct percutaneous transluminal coronary angioplasty in acute myocardial infarction: relationship with wall motion and functional response to dobutamine stimulation.

Reverse redistribution (RR) of 99mTc-sestamibi is observed after direct percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI). The purpose of this study was to clarify the functional characteristics of myocardial segments with RR after direct PTCA in AMI. Thirty patients with AMI who had undergone direct PTCA were examined. Myocardial perfusion tomography with 99mTc-sestamibi and low dose dobutamine echocardiography were performed within 2 weeks of the onset. The 99mTc-sestamibi images were obtained 1 and 3 h after tracer administration. The left ventricle was divided into nine segments, and regional 99mTc-sestamibi uptake and clearance were quantitatively evaluated in each segment. RR was defined as a decrease in 99mTc-sestamibi uptake of >10% on 3 h delayed images compared with the 1 h early images. The left ventricle in the echocardiographic images was also divided into nine segments corresponding to the scintigraphic images, and regional wall motion was assessed in the resting condition as the baseline and during dobutamine administration (5-10 microg x kg(-1) x min(-1)). Out of a total of 270 myocardial segments, 111 segments were perfused by the culprit coronary artery and were defined as ischaemic segments. There were 25 segments with RR and 86 segments without RR in the ischaemic myocardium. Enhanced clearance of 99mTc-sestamibi was observed in ischaemic segments with RR (P<0.001). Echocardiography demonstrated that 24 out of 25 segments with RR and 61 out of 86 segments without RR had wall motion abnormalities. Dobutamine infusion improved wall motion in 20 (83%) of the 24 dysfunctional segments with RR and 33 (54%) of the 61 dysfunctional segments without RR (P<0.02). These findings suggest that RR indicates reversible functional abnormalities associated with preserved contractile reserve in response to dobutamine. The early and delayed imaging of 99mTc-sestamibi provides useful information regarding the residual viability of the dysfunctional myocardium in AMI patients.

Acute Disease↗

PubMed2001

G2/M-phase-specific transcription during the plant cell cycle is mediated by c-Myb-like transcription factors.

Plant B-type cyclin genes are expressed specifically in late G2- and M-phases during the cell cycle. Their promoters contain a common cis-acting element, called the MSA (M-specific activator) element, that is necessary and sufficient for periodic promoter activation. This motif also is present in the tobacco kinesin-like protein gene NACK1, which is expressed with timing similar to that of B-type cyclin genes. In this study, we show that G2/M-phase-specific activation of the NACK1 promoter also is regulated by the MSA element, suggesting that a defined set of G2/M-phase-specific genes are coregulated by an MSA-mediated mechanism. In a search for MSA binding factors by yeast one-hybrid screening, we identified three different Myb-like proteins that interact specifically with the MSA sequence. Unlike the majority of plant Myb-like proteins, these Myb proteins, NtmybA1, NtmybA2, and NtmybB, have three imperfect repeats in the DNA binding domain, as in animal c-Myb proteins. During the cell cycle, the level of NtmybB mRNA did not change significantly, whereas the levels of NtmybA1 and A2 mRNAs fluctuated and peaked at M-phase, when B-type cyclin genes were maximally induced. In transient expression assays, NtmybA1 and A2 activated the MSA-containing promoters, whereas NtmybB repressed them. Furthermore, expression of NtmybB repressed the transcriptional activation mediated by NtmybA2. Our data show that a group of plant Myb proteins that are structurally similar to animal c-Myb proteins have unexpected roles in G2/M-phase by modulating the expression of B-type cyclin genes and may regulate a suite of coexpressed genes.

Base Sequence↗

PubMed2001

Two cases of unilateral pigmented purpuric dermatosis.

Two cases of pigmented purpuric dermatosis showing unusual distribution are reported. Case 1: 35-year-old female. A group of three asymptomatic purpuric macules developed on the ulnar side of the elbow flexure of the left forear 3-6 months before presentation. Histopathological analysis revealed a band-like inflammatory infiltrate in the Uppermost dermis and extravasation of red blood cells just beneath the epidermis, but there was no evidence of lichefaction degeneration in the basal layer of the epidermis. Case 2: 26-year-old female. Asymptomatic purpuric pigmentations developed on the flexure side of the right lower extremity in a linear arrangement 2-3 months before presentation. Histopathological analysis revealed focally perivascular inflammatatory infiltrates consisting mainly of lymphocytes and conspicuous extravasation of red blood cells into the papillary dermis. There was no histological evidence of vasculitis in either case. Hemosiderin deposits were more limited than expected in both patients. Both cases are compatible with diagnoses of pigmented purpuric dermatosis. Case 1 on the left arm was compatible with lichen purpuricus. Case 2 occurred in a linear arrangement on the right leg and had a history of aspirin use for chronic headache. We therefore suspected that medication had been an etiological or contributing factor.

Adult↗

PubMed2001

In vivo effects of a histone deacetylase inhibitor, FK228, on human acute promyelocytic leukemia in NOD / Shi-scid/scid mice.

Histone acetylation and deacetylation are closely linked to transcriptional activation and repression, respectively. In acute promyelocytic leukemia (APL), histone deacetylase inhibitors (HDACIs) have a synergistic effect with all-trans retinoic acid (ATRA) in vitro to induce differentiation. Here we report in vitro and in vivo effects of a HDACI, FK228 (formerly FR901228 or depsipeptide), on the human APL cell line NB4. FK228 had a strong and irreversible cytotoxicity compared with another HDACI, trichostatin A. In vivo administration of ATRA or FK228 alone partly inhibited the growth of established tumors of NB4 subcutaneously transplanted in NOD / Shi-scid / scid mice, and the combination was synergistically effective. Histopathological examination revealed that the combination induced apoptosis and differentiation as well as histone acetylation. Intravenous injection of NB4 in NOD / Shi-scid / scid mice followed by combination treatment significantly prevented leukemia death, whereas single administration did not. These findings suggest that FK228 is a promising agent to enhance ATRA-sensitivity in the treatment of APL.

Animals↗

PubMed2001

Identification of cyclophilin B-derived peptides capable of inducing histocompatibility leukocyte antigen-A2-restricted and tumor-specific cytotoxic T lymphocytes.

We recently suggested that cyclophilin B (Cyp-B) is a tumor antigen recognized by histocompatibility leukocyte antigen (HLA)-A24-restricted and tumor-specific cytotoxic T lymphocytes (CTLs). In this study, we tried to identify Cyp-B-derived epitopes, which can induce HLA-A2-restricted and tumor-specific CTLs in cancer patients. The tumor-infiltrating lymphocytes (TILs) from an HLA-A0207 patient with colon cancer were found to respond to COS-7 cells when co-transfected with the Cyp-B gene and either HLA-A0201, -A0206, or -A0207 cDNA. These TILs contained CTLs capable of recognizing either the Cyp-B(129 - 138) or the Cyp-B(172 - 179) peptide among 28 different peptides, all of which were prepared based on the HLA-A2 binding motif. Both Cyp-B peptides possessed the ability to induce tumor-specific CTLs in HLA-A2(+) cancer patients. Cyp-B(172 - 180 (V)), which is a 9-mer peptide with valine added at the C terminus, showed no clear superiority over the parental Cyp-B(172 - 179) peptide in an in vitro sensitization experiment. In vitro-sensitized T cells with these peptides responded to cancer cells in an HLA-A2-restricted manner. These two Cyp-B peptides could be useful for specific immunotherapy of HLA-A2(+) cancer patients.

Adenocarcinoma↗

PubMed2001

On the effectiveness of whole spectral shape for vowel perception.

The formant hypothesis of vowel perception, where the lowest two or three formant frequencies are essential cues for vowel quality perception, is widely accepted. There has, however, been some controversy suggesting that formant frequencies are not sufficient and that the whole spectral shape is necessary for perception. Three psychophysical experiments were performed to study this question. In the first experiment, the first or second formant peak of stimuli was suppressed as much as possible while still maintaining the original spectral shape. The responses to these stimuli were not radically different from the ones for the unsuppressed control. In the second experiment, F2-suppressed stimuli, whose amplitude ratios of high- to low-frequency components were systemically changed, were used. The results indicate that the ratio changes can affect perceived vowel quality, especially its place of articulation. In the third experiment, the full-formant stimuli, whose amplitude ratios were changed from the original and whose F2's were kept constant, were used. The results suggest that the amplitude ratio is equal to or more effective than F2 as a cue for place of articulation. We conclude that formant frequencies are not exclusive cues and that the whole spectral shape can be crucial for vowel perception.

Humans↗

PubMed2001

Clinical evaluation of anti-tuberculous glycolipid immunoglobulin G antibody assay for rapid serodiagnosis of pulmonary tuberculosis.

Previously we reported the development of a highly sensitive enzyme-linked immunosorbent assay specific for anti-tuberculous glycolipid (anti-TBGL) for the rapid serodiagnosis of tuberculosis. In this study, the usefulness of an anti-TBGL antibody assay kit for rapid serodiagnosis was evaluated in a controlled multicenter study. Antibody titers in sera from 318 patients with active pulmonary tuberculosis (216 positive for Mycobacterium tuberculosis in smear and/or culture tests and 102 smear and culture negative and clinically diagnosed), 58 patients with old tuberculosis, 177 patients with other respiratory diseases, 156 patients with nonrespiratory diseases, and 454 healthy subjects were examined. Sera from 256 younger healthy subjects from among the 454 healthy subjects were examined as a control. When the cutoff point of anti-TBGL antibody titer was determined as 2.0 U/ml, the sensitivity for active tuberculosis patients was 81.1% and the specificity was 95.7%. Sensitivity in patients with smear-negative and culture-negative active pulmonary tuberculosis was 73.5%. Even in patients with noncavitary minimally advanced lesions, the positivity rate (60.0%) and the antibody titer (4.6 +/- 9.4 U/ml) were significantly higher than those in the healthy group. These results indicate that this assay using anti-TBGL antibody is useful for the rapid serodiagnosis of active pulmonary tuberculosis.

Antibodies, Bacterial↗

PubMed2001

Identification of Aichi virus infection by measurement of immunoglobulin responses in an enzyme-linked immunosorbent assay.

Using inhibitory enzyme-linked immunosorbent assay, seroconversions to Aichi virus were detected in 24 (42.9%) of 56 patients with gastroenteritis in six outbreaks. Virus-specific immunoglobulin M (IgM) was detected in convalescent-phase sera from 7 of 24 patients. Of the other 17 patients, 12 developed a significant increase in both IgA and IgG levels and 5 developed a significant increase in IgG alone.

Animals↗

PubMed2001

Hemagglutinin-neuraminidase-independent fusion activity of simian virus 5 fusion (F) protein: difference in conformation between fusogenic and nonfusogenic F proteins on the cell surface.

The fusion (F) protein of simian virus 5 (SV5) strain W3A is known to induce cell fusion in the absence of hemagglutinin-neuraminidase (HN) protein. In contrast, the F protein of SV5 strain WR induces cell fusion only when coexpressed with the HN protein, the same as do other paramyxovirus F proteins. When Leu-22 in the subunit F2 of the WR F protein is replaced with the counterpart (Pro) in the W3A F protein, the resulting mutant L22P induces extensive cell fusion by itself. In the present study, we obtained anti-L22P monoclonal antibodies (MAbs) 21-1 and 6-7, whose epitopes were located in the middle (amino acids [aa] 227 to 320) of subunit F1. The amino-terminal region (aa 20 to 47) of subunit F2 was also involved in the formation of MAb 21-1 epitope. Flow cytometric analysis revealed that both the MAbs reacted very faintly with native WR F protein that was expressed on the cell surface whereas they reacted efficiently with native L22P irrespective of whether it is cleaved into F1 and F2. However, by heating the cells at 47 degrees C after mild formaldehyde fixation, the epitopes for MAb 6-7 and mAb 21-1 in the WR F protein were exposed and the reactivity of the MAbs with the WR F protein became comparable to their reactivity with L22P. Thus, the two MAbs seem to distinguish the difference in native conformation between fusogenic mutant L22P and its parental nonfusogenic WR F protein. The native conformation of L22P may represent an intermediate between native and postfusion conformations of a typical paramyxovirus F protein.

Amino Acid Sequence↗

PubMed2001

High resistance of human parainfluenza type 2 virus protein-expressing cells to the antiviral and anti-cell proliferative activities of alpha/beta interferons: cysteine-rich V-specific domain is required for high resistance to the interferons.

Human parainfluenza type 2 virus (hPIV-2)-infected HeLa (HeLa-CA) cells and hPIV-2 V-expressing HeLa (HeLa-V) cells show high resistance to alpha/beta interferons (IFN-alpha/beta) irrespective of whether vesicular stomatitis virus or Sindbis virus is used as a challenge virus. When Sindbis virus is used, these cells show high susceptibility to human IFN-gamma. Furthermore, the multiplication of HeLa-V cells is not inhibited by IFN-alpha/beta. HeLa cells expressing the N-terminally truncated V protein show resistance to IFN-alpha/beta, showing that the IFN resistance determinant maps to the cysteine-rich V-specific domain. A complete defect of Stat2 is found in HeLa-CA and HeLa-V cells, whereas the levels of Stat1 expression are not significantly different among HeLa, HeLa-CA, HeLa-P, and HeLa-V cells, indicating that IFN-alpha/beta resistance of HeLa-CA and HeLa-V cells is due to a defect of Stat2. HeLa-SV41V cells show high resistance to all IFNs, and no expression of Stat1 can be detected. Stat2 mRNA is fully detected in HeLa-V cells. Stat2 was scarcely pulse-labeled in the HeLa-V cells, indicating that synthesis of Stat2 is suppressed or Stat2 is very rapidly degraded in HeLa-V cells. The V protein suppresses the in vitro translation of Stat2 mRNA more extensively than that of Stat1 mRNA. An extremely small amount of Stat2 can be detected in HeLa-V cells treated with proteasome inhibitors. The half-life of Stat2 is approximately 3.5 and 2 h in uninfected and hPIV-2-infected HeLa cells, respectively. This study shows that synthesis of Stat2 may be suppressed and Stat2 degradation is also enhanced in hPIV-2-infected HeLa and HeLa-V cells.

Antiviral Agents↗

PubMed2001

Ramosetron compared with granisetron for the prevention of vomiting following strabismus surgery in children.

BACKGROUND/AIMS: Postoperative vomiting occurs frequently after strabismus surgery in children. Granisetron, a selective 5-hydroxytryptamine type 3 receptor antagonist, is effective for the prevention of vomiting following paediatric strabismus surgery. Ramosetron, another new antagonist of 5-hydroxytryptamine type 3 receptor, has more potent and longer acting properties than granisetron against cisplatin induced emesis. This study was undertaken to compare the efficacy and safety of granisetron and ramosetron for the prevention of vomiting following strabismus surgery in children. METHODS: In a randomised, double blinded manner 80 children, aged 4-10 years, received intravenously granisetron 40 microg/kg or ramosetron 6 microg/kg (n=40 each) at the end of surgery. A standard general anaesthetic technique and postoperative analgesia were used. Emetic episodes and safety assessment were performed during the first 24 hours and the next 24 hours after anaesthesia. RESULTS: The percentage of patients who were emesis free during 0-24 hours after anaesthesia was 85% with granisetron and 90% with ramosetron, respectively (p = 0.369); the corresponding rate during 24-48 hours after anaesthesia was 70% and 95% (p = 0.003). No clinically serious adverse events caused by the study drug were observed in any of the groups. CONCLUSION: Prophylactic antiemetic therapy with ramosetron is comparable with granisetron for the prevention of vomiting during 0-24 hours after anaesthesia in children undergoing strabismus surgery. During 24-48 hours after anaesthesia, ramosetron is more effective than granisetron for prophylaxis against postoperative vomiting.

Analysis of Variance↗

PubMed2001

Expression of human beta-defensin 2 (hBD-2) in Helicobacter pylori induced gastritis: antibacterial effect of hBD-2 against Helicobacter pylori.

BACKGROUND: Human beta-defensin 2 (hBD-2) plays a role in the innate defence system at mucosal surfaces. Colonisation of Helicobacter pylori in the stomach is an important pathological factor in gastrointestinal illnesses, including gastritis, peptic ulcer, and gastric adenocarcinoma. AIMS: To evaluate the antibacterial role of hBD-2 against H pylori infection in the gastric mucosa. SUBJECTS: Biopsied gastric mucosa specimens from H pylori positive (n=6) and H pylori negative (n=6) individuals were used. H pylori was determined by the presence of urease activity and microscopic examination. METHODS: The specimens were examined for hBD-2 expression by reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and in situ hybridisation. The antibacterial effect of hBD-2 against H pylori was evaluated by the number of colony forming units of H pylori after incubation with 0, 10(-9), 10(-8), 10(-7), 10(-6), or 10(-5) M of hBD-2 peptide. RESULTS: All six H pylori positive specimens expressed a high level of hBD-2 mRNA while hBD-2 mRNA was not detected in the H pylori negative specimens by RT-PCR. Immunohistochemistry using anti-hBD-2 antiserum revealed that hBD-2 was expressed in the surface epithelium of H pylori infected specimens. In gastric specimens obtained after H pylori eradication, hBD-2 immunoreactivity had dramatically decreased. In situ hybridisation confirmed that hBD-2 transcripts were localised in the epithelium of H pylori infected gastric specimens. Incubation with hBD-2 reduced the growth rate of cultured H pylori in a dose dependent manner, and incubation with 10(-5) M hBD-2 completely inhibited the proliferation of H pylori. CONCLUSIONS: H pylori infection induces hBD-2 expression in the human gastric epithelium. hBD-2 inhibited the growth of H pylori in vitro, suggesting that hBD-2 plays an antibacterial role in H pylori induced gastritis.

Aged↗

PubMed2001

Effects of isometric training on the elasticity of human tendon structures in vivo.

The present study aimed to investigate the effect of isometric training on the elasticity of human tendon structures. Eight subjects completed 12 wk (4 days/wk) of isometric training that consisted of unilateral knee extension at 70% of maximal voluntary contraction (MVC) for 20 s per set (4 sets/day). Before and after training, the elongation of the tendon structures in the vastus lateralis muscle was directly measured using ultrasonography while the subjects performed ramp isometric knee extension up to MVC. The relationship between the estimated muscle force and tendon elongation (L) was fitted to a linear regression, the slope of which was defined as stiffness of the tendon structures. The training increased significantly the volume (7.6+/-4.3%) and MVC torque (33.9+/-14.4%) of quadriceps femoris muscle. The L values at force production levels beyond 550 N were significantly shorter after training. The stiffness increased significantly from 67.5+/-21.3 to 106.2+/-33.4 N/mm. Furthermore, the training significantly increased the rate of torque development (35.8 +/- 20.4%) and decreased electromechanical delay (-18.4+/-3.8%). Thus the present results indicate that isometric training increases the stiffness and Young's modulus of human tendon structures as well as muscle strength and size. This change in the tendon structures would be assumed to be an advantage for increasing the rate of torque development and shortening the electromechanical delay.

Adult↗

PubMed2001

Validity of estimating limb muscle volume by bioelectrical impedance.

The present study aimed to investigate the validity of estimating muscle volume by bioelectrical impedance analysis. Bioelectrical impedance and series cross-sectional images of the forearm, upper arm, lower leg, and thigh on the right side were determined in 22 healthy young adult men using a specially designed bioelectrical impedance acquisition system and magnetic resonance imaging (MRI) method, respectively. The impedance index (L(2)/Z) for every segment, calculated as the ratio of segment length squared to the impedance, was significantly correlated to the muscle volume measured by MRI, with r = 0.902-0.976 (P < 0.05). In these relationships, the SE of estimation was 38.4 cm(3) for the forearm, 40.9 cm(3) for the upper arm, 107.2 cm(3) for the lower leg, and 362.3 cm(3) for the thigh. Moreover, isometric torque developed in elbow flexion or extension and knee flexion or extension was significantly correlated to the L(2)/Z values of the upper arm and thigh, respectively, with correlation coefficients of 0.770-0.937 (P < 0.05), which differed insignificantly from those (0.799-0.958; P < 0.05) in the corresponding relationships with the muscle volume measured by MRI of elbow flexors or extensors and knee flexors or extensors. Thus the present study indicates that bioelectrical impedance analysis may be useful to predict the muscle volume and to investigate possible relations between muscle size and strength capability in a limited segment of the upper and lower limbs.

Adult↗