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Biomedical subjects

Y Furutani

Publications and source records attributed to Y Furutani.

At least 37 records · Page 2Linked to original sources
PubMed1998

Relative usefulness of measures of heart rate variability and neuroendocrine activity as indicators of autonomic nervous abnormality in patients with left ventricular dysfunction.

The aim of the study was to assess the relationship between changes in heart rate variability (HRV) and parameters of neuroendocrine activation in patients with various levels of left ventricular dysfunction. Measurements of HRV, plasma norepinephrine (PNE), and plasma atrial natriuretic peptide (ANP) were performed in 17 age- and gender-matched control subjects (group C) and in 39 patients with ischemic heart disease or cardiomyopathy who were subdivided into 3 equal groups according to their left ventricular ejection fraction: group N (normal); group M (mildly impaired); and group S (severely impaired). Spectral analysis of HRV (from 10-min electrocardiograms) was analyzed by the method of coarse-graining spectral analysis. PNE and ANP were significantly elevated in group S only (p<0.05). Log low-frequency power and log total power for group M were significantly lower than for group N (p<0.05). Log high-frequency power was significantly lower for group M than for group C (p<0.05). Thus, assessment of changes in HRV, which were observed earlier in the progress of left ventricular dysfunction than changes in neuroendocrine factors, may be a useful non-invasive method for the early detection of autonomic abnormality in patients with left ventricular dysfunction.

Aged↗
PubMed1998

The complete sequence and expression patterns of the atrial myosin heavy chain in the developing chick.

We have earlier reported partial cloning of a cDNA of a chick atrial myosin heavy chain (MHC) gene, CCSV2 and its expression pattern in embryonic chick hearts (Oana et al (1995) Eur J Cell Biol 67, 42-49). In this study, five overlapping cDNA clones (including CCSV2) which together encode the entire open reading frame of the chick atrial MHC gene were characterized, and both the entire nucleotide sequence consisting of 5825 bases and the deduced amino acid sequence consisting of 1931 amino acids determined. Reinvestigation of the nucleotide sequence of the previously reported and presumably different chick atrial specific MHC cDNA clone, AMHC1 (Yutzey et al (1994) Development 120, 871-883), revealed that our clone and AMHC1 encoded the same MHC. The chick atrial MHC gene was strongly expressed in developing chick atria from a very early stage (Hamburger and Hamilton stage 9, 29-33 h) to the adult stage. This gene was also expressed, although weakly, in the ventricle, somite (the precursor to skeletal muscle) and skeletal muscle during embryonic stages but not in adults.

Amino Acid Sequence↗
PubMed1997

[Influence of the dead space induced by the face mask on the measure of heart rate variability].

The respiratory pattern influences the power spectrum of heart rate variability and therefore control or monitoring of respiration is needed. The effect of the dead space induced by the face mask used in the expiratory gas exchange analysis on the measurement of heart rate variability was evaluated in 22 subjects (15 males and 7 females aged 39-76 years, mean 42 years) using electrocardiography recorded for 5 min during spontaneous respiration under the conditions of supine rest, sitting on the bicycle ergometer with and without a face mask. The power spectrum of heart rate variability was obtained by the coarse-graining spectral analysis (CGSA) method and the total power (TP : 0-0.5 Hz), low frequency component (LF: 0-0.15 Hz), high frequency component (HF: 0.15-0.50 Hz), HF/TP and LF/HF were measured. The volume of the face mask was 320 ml and the tidal volume during sitting with the face mask was 596 +/- 110 ml (444-808 ml). The value of LF/HF increased from supine rest to sitting in accordance to the change of body position (p < 0.05), but the value of LF/HF when sitting with the face mask decreased to the level during supine rest. The value of HF/TP decreased from supine rest to sitting (p < 0.05), but when sitting with the face mask returned to that during supine rest. To evaluate the effect of tidal volume, the subjects were divided into two groups (each of 11 subjects) by the median value of tidal volume (570 ml). The value of LF/HF decreased from supine rest to sitting with the face mask in the smaller tidal volume group (tidal volume < 570 ml) (p < 0.02). Moreover, there was a significant correlation between the change of the value of LF from supine rest to sitting with the face mask and the tidal volume (r = 0.44, p < 0.05). There results suggest that the power spectrum of heart rate variability is strongly influenced by the dead space induced by the face mask used in expiratory gas exchange analysis. In particular, the sympathetic activation from supine rest to sitting in subjects with the smaller tidal volume is unclear. Thus, interpretation of the results of heart rate variability with or without the face mask used in expiratory gas exchange analysis requires care.

Adult↗
PubMed1997

Quantification of area at risk in acute myocardial infarction by tomographic imaging.

UNLABELLED: The purpose of this study was twofold: to validate, in a phantom heart model, a simple threshold technique for the quantification of defect size using 123I-15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid (BMIPP) imaging and to compare, in patients with acute myocardial infarction, defect size as shown by BMIPP imaging, with the extent of severe hypokinesis shown by left ventriculography. METHODS: In a phantom study, defect size was calculated using a standard geometric formula. In a clinical study, BMIPP imaging was performed in 20 patients 10 +/- 5 days after the onset of their infarction. Using the centerline method, the area at risk was defined by contrast ventriculography as the percentage of chords with wall motion >2 s.d. below normal. RESULTS: In the phantom study, a threshold value of 60% yielded the best agreement between true and measured defect size. In the clinical study, the defect size shown by BMIPP imaging was greater in anterior than in inferior infarcts (p < 0.001) and correlated well with the risk area revealed by contrast ventriculography (r = 0.80, p < 0.0001) CONCLUSION: The above preliminary data, admittedly from a small group of patients, suggest that tomographic BMIPP imaging provides an accurate quantification of defect size by means of a simple threshold technique and, in the subacute phase, permits determination of the amount of myocardium at risk after acute myocardial infarction.

Coronary Angiography↗
PubMed1997

[Noninvasive hemodynamic assessment of internal thoracic artery grafts using duplex echocardiography from supraclavicular fossa--a comparison with Doppler catheter method].

We evaluated the usefulness of noninvasive hemodynamic assessment of internal thoracic artery grafts (ITAGs) using duplex Doppler echocardiography from the supraclavicular fossa (transcutaneous pulsed Doppler method: PD method). Eighteen ITAGs were examined by PD method in comparison with Doppler catheter method using Doppler flowire (DC method). The hemodynamic indices used were the diastolic/systolic peak velocity ratio (DSVR) and the diastolic fraction of time-velocity integral (DF) in the ITAGs. A significant linear correlation was seen both in DSVR and DF between these two methods (p < 0.01). The subjects were assigned to two groups according to angiographic findings Group A (Gr-A: 5 grafts) with string sign including significant graft stenosis and group B (Gr-B 13 grafts) with good patency. In both PD and DC methods, DSVR and DF were significantly lower in Gr-A than in Gr-B (p < 0.01). The blood flow pattern was thus systolic dominant in the grafts with string sign, while it was diastolic dominant in the grafts with good patency. In some grafts in Gr-B, however, both DSVR ad DF were as low as that in Gr-A. Responding to pacing, Gr-B further increased both DSVR and DF, but Gr-A did not. As a result, the difference between both groups was further distinguished. In summary, ITAG function can be assessed by the noninvasive PD method. Interventions such as exercise, dobutamine infusion may make it more accurate, particularly in evaluating borderline data.

Aged↗
PubMed1996

Isolation and characterization of mitochondrial nucleoids from the yeast Pichia jadinii.

Mitochondrial (mt) nucleoids were isolated with a high degree of purity from the yeast Pichia jadinii, in which the mitochondrial DNA (mtDNA) is linear. Field-inversion gel electrophoresis (FIGE) revealed that significant amounts of mtDNA could be isolated intact, as linear molecules of 41 kbp, from the isolated mt-nucleoids. Fifteen different proteins were detected in the mt-nucleoid fraction and, eight of these proteins bound to DNA. The patterns of mt-nucleoid proteins and of the DNA-binding proteins after gel electrophoresis in the presence of SDS were somewhat different from those of such proteins from Saccharomyces cerevisiae. The corresponding proteins isolated from the mt-nucleoids of four other species of yeast in the genera Pichia and Williopsis also differed from one another in terms of electrophoretic mobility in the presence of SDS. In immunoblotting experiments, antibodies that had been raised against the 67-kDa protein of mt-nucleoids from S.cerevisiae and the YMN-1 monoclonal antibody that is specific for a 48-kDa protein in the mt-nucleoids from S. cerevisiae did not recognize any proteins in the mt-nucleoids from Pichia jadinii and four other species of yeast. The results suggest the considerable diversity of the proteins in the mt-nucleoids of yeasts.

Animals↗
PubMed1996

Human endothelin converting enzyme gene (ECE1) mapped to chromosomal region 1p36.1.

The chromosomal localization of the human endothelin converting enzyme gene (ECE1) has been identified. Southern blot analysis of human genomic DNA from human x mouse somatic cell hybrids demonstrated that ECE1 maps to chromosome 1. Fluorescence in situ hybridization of a digoxigenin-labeled human ECE1 probe to normal human metaphase chromosomes showed that the gene is located within chromosome band 1p36.1.

Animals↗
PubMed1996

Expression of four myosin heavy chain genes in developing blood vessels and other smooth muscle organs in rabbits.

At least two smooth muscle myosin heavy chain (MHC) isoforms (SM1, SM2) and two non-muscle MHC isoforms (NMA, NMB) have been detected in smooth muscles. We used the S-1 nuclease mapping procedure to study the expression of these four types of MHC mRNAs in various rabbit blood vessels, such as the aorta (Ao), pulmonary artery (PA), inferior vena cava (IVC) and ductus arteriosus (DA), and in various rabbit tissues and organs. The results demonstrated that in the blood vessels, the four types of MHC mRNA were expressed during all developmental stages in Ao and PA and that SM2 expression appeared to increase dramatically after birth. Compared to the other fetal vessels, the fetal DA contained considerably higher amounts of the four types of MHC mRNAs. SM2 was more prevalent than SM1 in the esophagus, stomach, small intestine and urinary bladder, which are often stretched and show vigorous contractile activity. SM2 expression in a smooth muscle cell appears to correlate well with the contractile ability and/or activity of the cell. Our data show that among the four types of MHC mRNAs, the expression of SM2 MHC mRNA shows great variation among different organs, blood vessel types and stages of development of Ao and PA.

Amino Acid Sequence↗
PubMed1995

Missense mutation of the beta-cardiac myosin heavy-chain gene in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy occurs as an autosomal dominant familial disorder or as a sporadic disease without familial involvement. We describe a missense mutation of the beta-cardiac myosin heavy chain (MHC) gene, a G to T transversion (741 Gly-->Trp) identified by direct sequencing of exon 20 in four individuals affected with familial hypertrophic cardiomyopathy. Three individuals with sporadic hypertrophic cardiomyopathy, whose parents are clinically and genetically unaffected, had sequence variations of exon 34 of the alpha-cardiac MHC gene (a C to T transversion, 1658 Asp-->Asp, resulting in FokI site polymorphism), of intron 33 of the alpha-cardiac MHC gene (a G to A and an A to T transversion), and also of intron 14 of the beta-cardiac MHC gene (a C to T transversion in a patient with Noonan syndrome). Including our case, 30 missense mutations of the beta-cardiac MHC gene in 49 families have been reported thus far worldwide. Almost all are located in the region of the gene coding for the globular head of the molecule, and only one mutation was found in both Caucasian and Japanese families. Missense mutations of the beta-cardiac MHC gene in hypertrophic cardiomyopathy may therefore differ according to race.

Adolescent↗
PubMed1995

Molecular characterization of a novel atrial-specific myosin heavy-chain gene expressed in the chick embryo.

A 1.2 kb fragment of a myosin heavy-chain (MHC) gene was isolated from the complementary DNA (cDNA) library derived from embryonic day 15 (E15), Hamburger and Hamilton (H.H) stage 41 chick embryonic ventricle, using a fragment of human beta-cardiac MHC cDNA as a probe. DNA sequence analysis determined that the gene (CCSV2) encoded the amino acid sequence of the rod portion (part of S2 and light meromyosin) of the chick atrial-specific MHC gene. The nucleotide sequence of CCSV2 was slightly different (90% homologous) from a previously reported atrial-specific MHC (AMHC1) expressed in chick embryo. Northern blot analysis, with the CCSV2 fragment (1.2 kb) used as a probe, showed that the gene is expressed intensively in the developing chick atrial muscle, but weakly in the ventricle and pectoralis muscle. S1-nuclease mapping analysis, with CCSV2 used as a probe, demonstrated a fully protected fragment in the atrium and ventricle. In this study, no intensive signal of a partially protected fragment was detected in the atrium. On the other hand, not only a fully protected fragment, but also four partially protected fragments were observed in the pectoralis muscle. Whole-mount in situ hybridization was performed in developing chick heart at H.H. stages 19, 21 and 30. The hybridization signal was intensive in the primitive atrium (H.H. stages 19 and 21) and in the atrial appendages derived from the primitive atrium (H.H. stage 30). Weak signals were detected in the primitive ventricle (H.H. stages 19 and 21), the ventricle (H.H. stage 30) and in the somites (H.H. stages 19 and 21).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

Essential hypertension and neurovascular compression at the ventrolateral medulla oblongata: MR evaluation.

PURPOSE: To investigate, using MR imaging, neurovascular compression at the ventrolateral medulla oblongata in patients with essential hypertension. METHODS: Thirty-two patients with essential hypertension (57.6 +/- 7 years of age), 6 patients with secondary hypertension (56.7 +/- 10.3 years of age), and 18 control subjects (50.5 +/- 11 years of age) were evaluated. Transaxial three-dimensional fast low angle shot images were obtained (38/6/1 [repetition time/echo time/excitations]). The center of a 40-mm-thick slab (16 partitions) was placed at the pontomedullary junction. We evaluated the relationships between the upper ventrolateral medulla and the vertebral arteries and branches identified by their flow-related hyperintensities in each group. RESULTS: In the essential hypertension group, 29 (90.6%) of 32 cases showed neurovascular compression. Of those, 22 demonstrated neurovascular compression on the left side, 3 on both sides, and 4 on the right side. In the control group, 4 cases of 18 showed neurovascular compression. In the secondary hypertension group, 1 of 6 cases showed neurovascular compression. The rates of observed neurovascular compression between controls and essential hypertension group were statistically significant. CONCLUSION: We found a close correlation between essential hypertension and neurovascular compression at the ventrolateral medulla oblongata on the left side. MR with a 3-D fast low-angle shot sequence has acceptable spatial resolution and depicts blood vessels simultaneously by flow-related phenomena.

Adult↗
PubMed1994

Effect of left ventricular contractile performance on passive left atrial filling--clinical study using radionuclide angiography.

Many invasive and noninvasive methods have been used to study the cardiac atria; however, few allow quantitative measurement of atrial function. To determine the interaction between left ventricular (LV) contraction and left atrial (LA) filling, gated radionuclide angiography was conducted in 30 normal subjects (24 men and 6 women, mean age 58 +/- 10 years, range 26-68). LV and LA time-activity curves and their first-derivative curves were obtained simultaneously by using the method of Bough et al. The LV ejection fraction (64 +/- 18%) and LV peak ejection rate (LVPER; 3.42 +/- 0.27 EDV/s) were computed from these curves. As indices of LA filling, LA fractional emptying (38 +/- 12%) and LA peak filling rate (LAPFR; 2.86 +/- 0.17 LAVmax/s)--the latter being defined as the peak rate of LA filling during the LA filling phase--were also computed from these curves. In all subjects, the timing of the LVPER coincided with the occurrence of LAPFR, and there was a significant positive correlation between the LVPER and LAPFR (r = 0.81, p < 0.001), indicating that the LAPFR was strongly affected by the degree of LVPER. Thus, these results indicate that LV contractile performance plays an important role in determining LA passive filling during ventricular systole.

Adult↗
PubMed1993

Human smooth muscle myosin heavy chain gene mapped to chromosomal region 16q12.

The partial nucleotide sequence encoding the rod portion of the entire amino acid sequence of human smooth muscle myosin heavy chain (MHC) which corresponds to MYH11, according to Human Gene Mapping nomenclature, has been determined by cloning a complementary DNA (cDNA) and sequencing the cDNA (UMYHSM). Northern blot analysis with the UMYHSM fragment (4.3 Kb) showed that the smooth muscle MHC of the human umbilical artery is expressed in the human umbilical artery, bladder, esophagus and trachea. Southern blot analysis of human genomic DNA from human-mouse or human-Chinese hamster somatic cell hybrids demonstrated that the human smooth muscle MHC was mapped to human chromosome 16. Regional mapping of UMYHSM was performed using human cell lines with partial deletion and trisomy of chromosome 16. As a result, the human smooth muscle MHC gene segregated with 16p11-q12. In situ hybridization of biotin-labeled human smooth muscle MHC probe (UMYHSM fragment) to normal human metaphase chromosome independently showed that the human smooth muscle MHC gene (MYH11) is assigned to chromosome region 16q12. Analysis of early metaphase chromosomes showed that hybridization signals were in 16q12.1. In the human, although skeletal, cardiac, smooth muscle, and nonmuscle MHC genes are mapped to chromosomes 17, 14, 16, and 22, respectively, structural similarities of these MHC genes strongly suggest the common origin of these genes.

Amino Acid Sequence↗
PubMed1993

Age-related modification of regional left ventricular filling in normal subjects.

Left ventricular diastolic filling has been reported to be impaired with advancing age in normal subjects. To investigate the influence of regional ventricular diastolic asynchrony on global ventricular filling as a function of age and to assess the location of asynchronous regions within the left ventricle, radionuclide ventriculography was conducted in 48 normal subjects aged 15 to 73 years. Left ventricular regional filling was assessed by dividing the left ventricular region of interest into 4 quadrants, from which global, septal, apical and lateral time-activity curves and first-derivative curves were derived. Indexes of global left ventricular systolic function at rest did not correlate with age. However, indexes of global early diastolic filling declined significantly with age; peak filling rate normalized to end-diastolic volume (r = -0.42; p < 0.01), to stroke volume (r = -0.48; p < 0.001) and to peak ejection rate (r = -0.47; p < 0.001) decreased with advancing age. Global time to peak filling rate also increased with aging (r = 0.41; p < 0.01). Early diastolic asynchrony was measured as the sum of the absolute values of the time differences from global peak filling rate to that in each of three quadrants (delta TPFR). delta TPFR increased with age (r = 0.37; p < 0.01). Global peak filling rate normalized to end-diastolic volume (r = -0.40; p < 0.01), to stroke volume (r = -0.45; p < 0.01) and to peak ejection rate (r = -0.51; p < 0.001) decreased significantly with increasing delta TPFR. Time to peak filling rate of the lateral region occurred first (163 +/- 33 ms), followed by the apical (184 +/- 38 ms) and finally the septal region (195 +/- 35 ms). With regard to the sequence of regional filling, this suggests that a physiologic asynchrony exists in resting condition in normal subjects. Times to peak filling rate in the septal and apical regions were modestly correlated with age (r = 0.29; p < 0.05, r = 0.30; p < 0.05 respectively), but that in the lateral region did not show significant correlation with age. This may indicated that the effects of advancing age on the regional filling differ in regions within the left ventricle. These results suggest that aging alters left ventricular early diastolic filling in association with the increase in physiologic asynchrony.

Adolescent↗
PubMed1993

[Coronary artery bypass grafting in six patients with familial hypercholesterolemia].

UNLABELLED: From June 1989 through November 1991, six patients with familial hypercholesterolemia underwent surgical treatments. The surgical procedures were coronary artery bypass grafting (CABG) alone 4, ligation of coronary aneurysm + CABG 1, and CABG + femoro-femoral bypass 1. There were no operative or hospital deaths. Early post operative patency rate of the grafts was 100%. CASE PRESENTATION: A 44-year-old man whose anginal pain recurred 11 years after CABG. Coronary angiogram revealed stenosis and a large aneurysm in the circumflex coronary artery. Previous grafts to the left anterior descending coronary artery and diagonal branch were patent. Ligation of the aneurysm and internal mammary artery bypass grafting were performed. Postoperatively, the patient has remained asymptomatic. Our data indicate that CABG for FH patients is effective in the early postoperative period.

Adult↗
PubMed1993

[A case report of congenitally bicuspid aortic valve and ascending aortic aneurysm treated by wheat operation].

A 59-year-old man who complained of palpitation was diagnosed as having a congenitally bicuspid aortic valve, severe aortic regurgitation, and an ascending aortic aneurysm. He underwent aortic valve replacement and conduit replacement by the modified Wheat technique. Since this technique requires no coronary artery anastomosis, it causes no problems associated with reconstruction of the coronary artery. Postoperative angiogram revealed no aneurysm formation of the aortic root or paravalvular leakage. This case suggest that aneurysm of the ascending aorta with aortic regurgitation is more effectively treated by the modified Wheat technique if cephalad displacement of the coronary ostium is not extensive.

Aorta↗
PubMed1993

[Volume measurement of the horizontal extraocular muscles using magnetic resonance imaging].

The volume of the horizontal extraocular muscles of 11 normal adults and three patients with ophthalmoplegia was measured using magnetic resonance imaging (MRI). The MRI examinations were carried out with a Signa Advantage, 1.5 tesla superconductive magnetic system manufactured by General Electric. This method employs the spin echo technique with a 3.0 mm gapless slice, a 350 ms. repetition time, and a 17.0 ms. echo time. The MRI films were projected and magnified on Kent paper using an overhead projector. Then the shapes of the horizontal extraocular muscles were traced. The volume of the muscles was measured as the total weight of Kent papers which were cut out from muscle shapes in all the slices. The average volume of the normal medial and lateral rectus muscles was 690 +/- 87 mm3 and 734 +/- 77 mm3, respectively. Two cases with peripheral nerve palsy showed typical atrophy of the paretic muscles. A case with orbital myositis showed typical hypertrophy of the inflamed muscles. This measurement may prove useful in the analysis and evaluation of extraocular muscles, especially in ophthalmoplegia.

Adult↗