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Biomedical subjects

T Muro

Publications and source records attributed to T Muro.

At least 37 records · Page 2Linked to original sources
PubMed1999

Potential applications of intracardiac echocardiography in the assessment of the aortic valve from the right ventricular outflow tract.

Intracardiac echocardiography (ICE) is a developing technology and a promising method for visualizing intracardiac structures. However, its applications are currently limited to guidance during mitral valvuloplasty, catheter ablation, or electrophysiologic examination. The goal of this study was to observe the aortic valve, measure the annular diameter of the valve by ICE through a right-sided approach, and compare the results by ICE with those by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). We studied 18 patients (9 men, 9 women, aged 19 to 72 years) with various heart diseases, including 15 patients with mitral or aortic valvular disease. An imaging catheter was advanced through a long sheath into the outflow tract of the right ventricle. We obtained good longitudinal views of the aortic valve in all patients. Two of the 18 patients had poor image quality by TTE. The annular diameter by ICE correlated more closely with TEE than with TTE. In conclusion, right-sided ICE is a safe, simple, and useful procedure for observing the aortic valve during cardiac catheterization without additional discomfort in the patients. Right-sided ICE is superior to TTE in observing the aortic valve and measuring the annular diameter of the valve. The annular diameter can be measured by ICE as precisely as by TEE.

Adult↗
PubMed1999

Assessment of transmural coronary blood flow with intraoperative transesophageal color Doppler echocardiography during coronary revascularization.

Intraoperative color Doppler transesophageal echocardiography with a 4- to 7-MHz transducer was performed on 28 consecutive patients who underwent coronary artery bypass grafting to image and evaluate the transmural coronary blood flow before and after cardiopulmonary bypass. The transmural coronary flow was visualized in 26 (92.8%) of 28 patients in the inferior wall and in 13 (46.4%) of 28 patients in the lateral wall. The peak diastolic flow velocity of the transmural coronary artery in the inferior and lateral wall was significantly increased after coronary revascularization in patients with a successful bypass graft to the right coronary artery (from 34.0 +/- 19.7 to 64.9 +/- 30.9 cm/s, P <.001, n = 10) and to the left circumflex coronary artery (from 35.1 +/- 18.6 to 62.1 +/- 21.1 cm/s, P <.001, n = 10). No significant changes were observed in patients with no bypass graft to the right or left circumflex coronary artery. Coronary blood flow can be mapped and the velocity measured with Doppler transesophageal echocardiography with a high-frequency (4- to 7-MHz) transducer. Assessment of the transmural coronary flow may provide valuable information and aid in decision making during surgical revascularization.

Adult↗
PubMed1999

Reevaluation of discograms not classified into usual classifications.

Discograms of images that were eccentrically dyed because of insufficient infiltration of contrast medium are difficult to classify into the usual past discogram patterns. In this study, these types of images were detected in 40 discs of 36 patients with lumbar disc disease. We classified these images into the following three types, and analyzed the dye mechanisms in each case by computed tomography discographic findings: (1) type A (image of the annulus fibrosus only). Nine discs in nine cases. A part of the marginal annulus fibrosus was dyed. (2) type B (image of the right or left half of the nucleus pulposus). Eighteen discs in 15 cases. Unilateral dyeing was considered nucleus pulposus existing in the central region of the disc. (3) type C (partial image of the superior or inferior half of the nucleus pulposus). Thirteen discs in 12 cases. Only the superior or inferior half showing a cotton-ball pattern was dyed.

Adolescent↗
PubMed1998

Twin helical undulator beamline for soft X-ray spectroscopy at SPring-8.

A very high resolution soft X-ray beamline, BL25SU, has been designed and is under construction at SPring-8. Completely right or left circularly polarized light is supplied on a common axis of a newly designed twin helical undulator. A helicity modulation up to 10 Hz can be performed using five kicker magnets. The fundamental radiation covers the region 0.5-3 keV. Higher-order radiation is rather weak on the axis. A monochromator with varied-line-spacing plane gratings is installed to cover the region below 1.5 keV. A very high resolution beyond 10(4) is expected for the whole energy region.

Journal Article↗
PubMed1998

Consistency of lumbar discograms of the same disc obtained twice at a 2-week interval: influence of needle tip position.

: Although numerous papers have emphasized the importance of accurate needle positioning in lumbar discography, no concrete evidence is available to support this contention, and no study has evaluated the image consistency of discography as influenced by this factor. By observing the consistency of two images in relation to needle tip position we aimed to clarify the importance of needle positioning in discography. One hundred and ninety-two patients (324 discs) receiving steroid intradiscal therapy in whom discography of the same disc was performed twice at a 2-week interval and in whom the needle tip position was within the acceptable range (as defined by us) were studied. The patients were divided into two groups: in group G, in whom the needle tip was within a limited range on both discograms, and group P, in whom the needle tip was in this range on only one discogram. Image consistency was compared roentgenographically in the two groups. The consistent image rate for the total number of discs was 48.5%, being significantly higher in group G (53.2%) than in group P (39.0%). The rates were lower in the nucleus pulposus and the posterior portion of the disc than in the other disc areas, but were significantly higher in group G (85. 4% and 75.0%, respectively, for these two areas). The necessity for accurate needle tip positioning was proved roentgenographically.

Adolescent↗
PubMed1997

A unique enzyme from Saccharothrix sp. catalyzing D-amino acid transfer.

A newly isolated actinomycete belonging to Saccharothrix sp. was found to produce a unique enzyme catalyzing D-amino acid transfer. The enzyme, which was tentatively named D-amino acid transferase, was purified 2600-fold to electrophoretic homogeneity and the molecular mass was 41 kDa. The enzyme was D-configuration specific and recognized aromatic D-amino acid esters to form oligo D-amino acid esters. D-Phenylalanine ester was favored as substrate over other D-amino acid esters. The optimum conditions for oligo D-phenylalanine ester formation by D-amino acid transferase were pH 7.0 and 40 degrees C. The enzyme was inhibited by DAN, EPNP and DFP.

Actinomycetales↗
PubMed1996

Irreducible fracture of the neck of the fifth metacarpal.

We report a rare case of fracture of the neck of the fifth metacarpal which required open reduction. The radial and ulnar collateral ligaments entrapped the displaced metacarpal head. This patho-anatomy resembles that of rotational supracondylar fractures of the proximal phalanx.

Aged↗
PubMed1995

Physical and gene organization of mitochondrial DNA from the fertile cytoplasm of sugarbeet (Beta vulgaris L.).

We have constructed a complete physical map of the mitochondrial genome from the male-fertile cytoplasm of sugarbeet. The entire sequence complexity can be represented on a single circular master chromosome of 358 kb. This master chromosome contains three copies of one recombinationally active repeat sequence, with two copies in direct orientation and the other in inverted orientation. The positions of the rRNA genes and of 23 polypeptide genes, determined by filter hybridization, are scattered throughout the genome, with triplicate rrn26 genes located partially or entirely within the recombination-repeat elements. Three ribosomal-protein genes (rps1A, rps14 and rps19) were found to be absent from sugarbeet mtDNA. Our results also reveal that at least six regions homologous with cDNA are dispersed in the mitochondrial genome.

Chromosome Mapping↗
PubMed1995

Purification and some properties of a protease from Streptomyces limosus.

Streptomyces limosus was selected because it secreted a novel protease that catalyzed the synthetic reaction forming Pro-Pro-Pro from Pro-Pro. The protease was purified to an electrophoretically homogeneous state and an activity of more than about 20,000-fold that of the culture broth. The molecular mass of the enzyme was estimated to be 50 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme was most active in alkaline pH for the synthetic reaction producing Pro-Pro-Pro from Pro-Pro, although for the hydrolytic reaction forming proline it was most active in neutral pH. The enzyme was inhibited by 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) and diazoacetyl-DL-norleucine methyl ester (DAN). It can be considered that this enzyme belongs to the class of aspartic proteases. The substrate specificity indicates that this enzyme has a strong affinity for proline as a N-terminal amino acid of peptides.

Amino Acid Sequence↗
PubMed1992

Bone scans in patients with osteoarthritis of the hip for the evaluation of bipolar hip arthroplasty: quantitative analysis using SPECT.

To establish the time-course of bone scans after bipolar hip arthroplasty (BHA) bone scanning was performed before and after surgery in 22 hips. The influence of migration of the outer head into the acetabulum on the time-course of bone scans was examined by analyzing the relationship between the uptake of radioisotope and the magnitude of migration. The bone scans were quantitatively analyzed by single photon emission computed tomography (SPECT) on the basis of the ratio of radioactivity at the acetabulum to that in the anterior superior iliac spine (ASIS). The increased radionuclide activity decreased exponentially to a baseline with time after surgery. The postoperative uptake ratio could be expressed as a function of the preoperative uptake ratio and the postoperative length of time. The regression slope representing the decreasing rate of uptake showed no significant differences between two groups divided by the magnitude of migration of the outer head. Migration of the outer head was considered not to influence the time-course of the bone scans.

Adult↗
PubMed1992

Pain provocation at lumbar discography as analyzed by computed tomography/discography.

Pain provocation was analyzed in 1477 intervertebral discs in 523 patients subjected to lumbar computed tomography/discography. The relation between pain provocation and the degree of general degeneration and anular disruption assessed according to the Dallas Discogram Description as indices of intradiscal deterioration was investigated. Pain provocation was also evaluated after categorizing the discs by the clinical diagnosis. Pain provocation showed little relation to intradiscal deterioration, whereas a strong relation was found between it and herniated nucleus pulposus. in herniated nucleus pulposus, discs with extraligamentous extrusion or sequestration, large protrusions, maximum protrusion site at the nerve root portion, and herniation routes passing through the central portion of the disc showed a high pain provocation ratio. Pain provocation ratios of discs associated with spinal canal stenosis were extremely low.

Adolescent↗
PubMed1992

Pathoanatomy of lumbar disc herniation as demonstrated by computed tomography/discography.

Computed tomography/discography was performed in 378 patients (403 discs) with lumbar disc herniation receiving intradiscal therapy. The grade of disc degeneration defined by the Dallas discogram description correlated closely with age. The most common herniation routes ran through the central portion of the posterior aspect of the disc (48.9%), through the paracentral portion (18.6%) and through the entire central portion (9.7%), with these directions parallel to the sagittal plane. However, the intraforaminal and extraforaminal routes (4.2%) passed obliquely to the sagittal plane. The development of these herniation routes has been well explained by the findings of earlier histopathologic and biomechanical studies. Computed tomography/discography was very useful in observing the detailed features of HNP such as the range, site of maximum protrusion and protrusion size.

Adolescent↗
PubMed1991

An observation of ruptured annulus fibrosus in lumbar discs.

To observe anatomical or pathological changes in lumbar intervertebral discs, discography and computed tomography-discography (CTD) were performed on fresh human cadavers. The results of discograms and CTD were compared with histological findings of cross sections of discs. Preoperative CTD of lumbar disc herniation was investigated based on these results. Ruptures of the annulus fibrosus were divided into two categories: circumferential rupture and radial rupture. In CTD images of fresh human cadavers, most images of rupture of the annulus fibrosus showed anterior to lateral circumferential rupture. As disc degeneration progressed, circumferential rupture tended to coexist with radial rupture in many cases. In CTD cases of lumbar disc herniation, most images of ruptures of the annulus fibrosus showed a posterior radial rupture, which was the route for herniated nucleus. The greater the degree of degeneration, the more the images tended to show radial ruptures coexisting with circumferential ruptures.

Adult↗
PubMed1991

Purification and some properties of protease I having transfer action from Streptomyces griseus var. alcalophilus.

Streptomyces griseus var. alcalophilus was selected because it secreted a unique protease (protease I) that catalyzed the transfer reaction forming the hydroxamic acids of various amino acids. Protease I was purified to the electrophoretically homogeneous state and an activity of more than 125-fold that of the culture broth. The molecular weight of the enzyme was estimated to be 25,000 by gel filtration. The enzyme was most active in neutral pH for the transfer reaction forming phenylalanine hydroxamic acid, although for the hydrolytic reaction with casein as substrate it was most active in alkaline pH. The enzyme was inhibited by diisopropylfluorophosphate. Protease I catalyzed the transfer reaction synthesizing the hydroxamic acids of hydrophobic, acidic, basic, and small aliphatic amino acids such as Phe, Tyr, Leu, Asp, Glu, Arg, Lys, Ala, and Gly. These results indicate that protease I has broad donor specificity. It is also considered that protease I is a unique enzyme with transfer activity, and distinct from the alkalophilic proteinase reported previously [Yamamoto et al., Agric. Biol. Chem., 38, 37 (1974)].

Amino Acid Sequence↗
PubMed1991

[Crossed cerebellar diaschisis and crossed cerebellar atrophy in a patient with a lesion in brain stem].

We report a 54-year-old woman who revealed right hemiparesis and ataxia in her right extremities due to a lesion which was suggested to be cavernous hemangioma located in the left side of pons in 1971, and showed remarkable crossed cerebellar atrophy (CCA) by computed tomography and magnetic resonance imaging in 1985 and 1989. Angiography showed no abnormality but made iatrogenic embolism in left thalamus which developed severe pain in her right side. Single-photon-emission-computed-tomography (SPECT) with I123-IMP in 1989 showed reduction of right cerebellar hemispheric blood flow (crossed cerebellar diaschisis: CCD) and left cerebral hemispheric blood flow. Our case was thought to have revealed persisting CCD. Although there are many reports about CCD and CCA following cerebral damage, CCD and CCA due to brain stem lesion has not been described yet. This might be explained by the persisting functional depression of cerebro-ponto-cerebellar pathways at the pons' level by cavernous hemangioma. It was assumed that the left cortical hypometabolism was result from damage to thalamo-cortical pathways due to ipsilateral thalamic lesion.

Atrophy↗