Biomedical subjects

M Yamagishi

Publications and source records attributed to M Yamagishi.

At least 19 recordsLinked to original sources

PubMed1997

Usefulness of myocardial velocity gradient derived from two-dimensional tissue Doppler imaging as an indicator of regional myocardial contraction independent of translational motion assessed in atrial septal defect.

Independence of myocardial velocity gradient from translational motion of the heart was tested by comparing normal subjects and patients with atrial septal defect. Myocardial velocity gradient obtained from patients fit within the normal range, even though the translation of the left ventricle was exaggerated in patients, demonstrating the translation independence of myocardial velocity gradient in clinical settings.

Adolescent↗

PubMed1997

Laboratory diagnosis of anemia and related diseases using multivariate analysis.

To establish a simple computer program for the laboratory diagnosis of anemia and related diseases, multivariate analyses were applied to the results of routine hematological laboratory tests obtained from 48 patients and 51 healthy volunteers. The patients studied were limited to those who had not been treated hematologically by the time of their first visit to our hospital, and their first data obtained in our laboratory were analyzed. Final diagnoses were aplastic anemia (AA) in 21, myelodysplastic syndrome (MDS) in 14, iron deficiency anemia (IDA) in 3, polycytemia vera (PV)in 3, and idiopathic thrombocytopenic purpura (ITP) in 7. Eight parameters, WBC, RBC, Hb, Ht, MCV, MCH, MCHC, and PLT, were transformed to normal distribution and then applied to principal component analysis to evaluate their independence. Very close relationships were observed between Ht and Hb, and between MCV and MCH. One each of these pairs was selected by discriminant analysis and two sets, RBC, MCH, Hb, PLT, and WBC, and RBC, MCV, Ht, PLT, and WBC, were obtained. Two canonical components gave good discrimination of these five diseases and also of normal subjects. When disease prediction was made using this analysis, 37 of 48 patients (77.1%) were predicted correctly, and furthermore, when two disease predictions were allowed, all patients were diagnosed properly. Some overlaps were observed in this two-dimensional coordinate system, especially of AA and MDS, and also with normal subjects. To improve the system further, the additional parameters of age and sex were added to construct a three-dimensional analysis which resulted in much clearer discrimination. The whole procedure described is being developed with subjects who are not taking medication. Subsequently, the general application of this analytical procedure should be limited to only those not on medications. In conclusion, this is in essence a demonstration project; however, this trial of laboratory diagnosis using routine hematological laboratory results appears to be promising. Further extension of the study by increasing numbers of patients and disorders studied, including secondary anemias, will allow the design of diagnostic software for use with personal computers at the sites of primary care.

Adult↗

PubMed1997

[Fibrin glue spray treatment on the polytetrafluoroethylene graft].

An outer surface of a 4 mm polytetrafluoroethylene (PTFE) prosthesis, Gore-Tex thin-walled stretch graft, was treated by the fibrin glue spray with a 1.0 kg/m2 compressed air. The distance between the PTFE graft and a spray-nozzle was within 0.5 cm. After the treatment, an outer surface and a cross-section of the PTFE graft were examined under a scanning electron microscope. Fibrin glue mended the gap of the PTFE fibril of an outer surface and a fibrin glue layer adhered firmly to the graft. The fibrin glue spray treatment may prevent postoperative serous fluid leakage.

Aerosols↗

PubMed1997

[Appropriate early open heart palliation of univentricular atrioventricular connection with subaortic stenosis].

Long-term conventional pulmonary artery banding deteriorates ventricular function in patients who have univentricular atrioventricular connection with subaortic obstruction. Protection of the pulmonary vascular bed and early relief of subaortic stenosis is essential to improve the outcome after Fontan operation. From January 1995 through January 1996, three infants underwent open heart palliation because of univentricular atrioventricular connection with subaortic stenosis. All infants had discordant ventriculoarterial connection. One infant underwent the Norwood procedure (patient 1). Two infants underwent palliative arterial switch operation, one with repair of aortic arch and a Blalock-Taussig shunt (patient 2) and the other with endoluminal pulmonary artery banding (patient 3). Patient 3 required a subsequent conventional pulmonary arterial banding. The postoperative recovery period were smooth in the all infants. All infants kept sufficient PO2 ranging from 34 to 37 mmHg postoperatively. On follow-up after 16 months pulmonary artery index decreased in patient 1. On the other hand, angiogram demonstrated satisfactory pulmonary arterial growth in patient 2. There were two late death, occurring in patient 1 (sudden death) and patient 3 (pneumonia). Patient 2 awaits a Fontan type procedure. It is difficult to adjust appropriate blood flow through a Blalock-Taussing shunt and a surgically isolated pulmonary artery is capable of inducing pulmonary distortion after Damus-Norwoood type operation. Whereas natural regulation of the pulmonary arterial blood flow by a restrictive ventricular outflow tract is come up after a palliative arterial switch operation. Palliative arterial switch operation is an useful alternative open heart palliation for neonates and early infants who had univentricular atrioventricular connection with subaortic stenosis.

Aortic Valve Stenosis↗

PubMed1996

Wall composition in intravascular ultrasound layered appearance of human coronary artery.

To evaluate the impact of histological factors on the appearance of the wall of the coronary artery by intravascular ultrasound (IVUS), we performed an in vitro study of 34 coronary artery segments from eight autopsied patients. We assumed the coronary cross section to be divided into four equal parts, and assessed the quadrants with maximal and minimal wall thickness by IVUS (30 MHz; 4.3 Fr; 1800 rpm) and by a histological study. The histological layer thickness and composition were also evaluated in terms of their contribution to the appearance of the ultrasound layer. Fifty-eight quadrants were clearly visible on ultrasound. A three-layered appearance, with inner echogenic, subjacent sonolucent, and outer echogenic layers, was observed in 32 quadrants, while 26 quadrants showed a two-layered appearance with inner and outer echogenic layers. The thickness of the inner echogenic layer (0.77 +/- 0.38 mm) was moderately correlated with the intimal thickness (0.51 +/- 0.45 mm; r = 0.85, standard error of estimate [SEE] = 0.24 mm); however, the correlation was significantly improved when the thickness of the inner echogenic plus sonolucent layers (0.89 +/- 0.47 mm) was compared with that of the intima plus media (0.69 +/- 0.47 mm; r = 0.94, SEE = 0.15 mm; P = 0.012 between the coefficients). Discriminant analysis showed that intimal hyalinization, associated with intimal thickening, was strongly related to the presence of the three-layered appearance on IVUS (F to enter 40.0, P < 0.0001). These results indicate that the ultrasound layered appearance of human coronary arteries varies with histological alterations. We suggest that the thickness of the inner echogenic plus sonolucent layers on IVUS represents the intimal plus medial thickness observed by histology, and that the use of this value may be appropriate in the assessment of coronary wall thickening associated with atherosclerosis.

Aged↗

PubMed1996

Intravascular ultrasound evidence of angiographically undetected left main coronary artery disease and associated trauma during interventional procedures.

To determine the clinical significance of angiographically undetected left main coronary artery (LMCA) disease, we analyzed data from 47 patients, with a mean age of 58 years, who were examined with intravascular ultrasound (3.5 Fr, 30 MHz). For assessment of atherosclerosis, the lesion area was calculated from the ultrasound images of the formula, [(total vessel area--lumen area)/total vessel areas] x 100(%). In 37 LMCA segments of patients with significant distal coronary stenosis (> 50%), the percent intima-media area (the index) was 39 +/- 11% (mean +/- SD), significantly greater than that of 10 patients without distal disease (27 +/- 4%, P < 0.01). Among those with significant coronary stenosis, the index was markedly greater in patients with multi-vessel coronary stenosis (46 +/- 12%, n = 19) than in patients with single-vessel disease (33 +/- 9%, n = 18; P < 0.01). At three LMCA sites associated with multi-vessel disease, ultrasound analysis demonstrated disruption of the intima at the site where the guiding catheter for balloon angioplasty had been positioned. These results indicate that LMCA disease is more prominent in patients with multi-vessel distal coronary disease than in those with single vessel disease, even in the absence of angiographic stenosis. We suggest that LMCA trauma can occur where the guiding catheter for angioplasty is positioned, particularly in patients with multi-vessel distal disease.

Adult↗

PubMed1996

Functional behavior and morphology of the coronary artery wall in patients with Kawasaki disease assessed by intravascular ultrasound.

OBJECTIVES: To examine the development of coronary artery lesions in Kawasaki disease, we assessed the functional behavior and morphology of coronary arteries by intravascular ultrasound. BACKGROUND: Long-term follow-up studies of patients with Kawasaki disease have demonstrated the development of localized coronary stenoses even after aneurysms have regressed. It is also possible that angiographically normal coronary segments in patients with this disease may retain histologic changes. METHODS: Twenty-three patients followed up by serial coronary angiography were examined at a mean age +/- SD of 14.9 +/- 2.9 years. The thickness of the intima-media complex was measured by intravascular ultrasound (30 MHz; 3.5 or 4.3 F; 1,800 rpm). Coronary reactivity to nitroglycerin was determined by measuring percent changes in cross-sectional coronary artery area after intracoronary injection (7 microgram/kg body weight) of this agent. RESULTS: A remarkably thickened intima-media complex was observed at the sites with persisting (0.54 +/- 0.20 mm, n = 19) and regressed (0.84 +/- 0.40 mm, n = 23) aneurysms. Mild thickening of the intima-media complex was often observed even in angiographically normal segments (0.22 +/- 0.05 mm, n = 31), in the left main coronary artery (0.47 +/- 0.15 mm, n = 20) and at normal branches (0.36 +/- 0.09 mm, n = 13). Coronary reactivity to nitroglycerin was significantly lower at the sites of regressed aneurysms (12.8 +/- 6.6%, n = 9) than in normal segments (32.8 +/- 10.9%, n = 13, p < 0.01), indicating the presence of functional impairment at the sites with regressed aneurysms. Decreased nitroglycerin reactivity was also observed in some segments without evidence of aneurysm. CONCLUSIONS: These results indicate that in patients with Kawasaki disease the coronary disease accompanying impaired reactivity to nitroglycerin is present at the sites of regressed aneurysms as well as in angiographically normal coronary segments. We suggest that these sites with morphologic and functional abnormalities are related to the development of significant stenosis.

Adolescent↗

PubMed1996

Molecular assembly of RNA polymerase II from the fission yeast Schizosaccharomyces pombe: subunit-subunit contact network involving Rpb5.

BACKGROUND: Eukaryotic RNA polymerase II is composed of more than 10 polypeptide chains. The minimum and essential subunits for RNA synthesis have not yet been identified. Toward this ultimate goal, we analysed the topological arrangement of the putative subunits. Here we report a subunit-subunit contact network involving subunit 5 of the fission yeast Schizosaccharomyces pombe RNA polymerase II. RESULTS: The rpb5+ gene encoding subunit 5 of RNA polymerase II was cloned from the fission yeast Schizosaccharomyces pombe. The polypeptide predicted from DNA sequence of the rpb5+ gene consists of 210 amino acids with a calculated molecular weight of 23914. The homology of the amino acid sequence is 55% and 43% with Saccharomyces cerevisiae RPB5 and human hRPB25, respectively. Far-Western blot analysis of S. pombe RNA polymerase II using 32P-labelled recombinant Rpb5 fused to glutathione S-transferase (GST) as a probe, indicated that Rpb5 binds strongly to membrane-immobilized Rpb1, Rpb2 and Rpb3 and weakly to Rpb5 and a 15-kDa subunit (Rpb8 or Rpb11). In agreement with this result, the 32P-labelled Rpb3 probe showed a strong binding signal against Rpb5 in addition to Rpb1 and Rpb2. The existence of Rpb5-Rpb3 contact was supported by detection of complexes formed between these two proteins synthesized in vitro using protein-immobilized beads. CONCLUSION: Rpb3 and Rpb5, the putative subunits of RNA polymerase II, associate each other to form binary complexes. These two subunits also bind to the two large subunits, Rpb1 and Rpb2, independently.

Amino Acid Sequence↗

PubMed1996

Ontogenetic expression of spot 35 protein (calbindin-D28k) in human olfactory receptor neurons and its decrease in Alzheimer's disease patients.

Expression of a calcium-binding protein, spot 35 protein (S-35, calbindin-D28k), was investigated immunohistochemically in the human olfactory mucosa of patients who ranged in age from 16 weeks of fetal development to 98 years old, including some with Alzheimer's disease (AD). S-35 immunoreactivity was observed clearly in olfactory receptor neurons (ORNs) and olfactory nerve bundles that were identified previously with antibodies to olfactory marker protein (OMP) and neuron-specific enolase (NSE). Throughout all ages, the mean number of ORNs immunoreactive for OMP did not change significantly, whereas the mean number of NSE- and S-35-immunoreactive ORNs declined markedly in the postnatal infant, young, and old patients when compared with that of the prenatal fetuses. S-35-immunoreactive ORNs decreased significantly in AD patients when compared with AD control patients. These results indicate that ORNs in humans express S-35 and that there is an age-related trend in the expression of S-35. Furthermore, the marked decrease of S-35 expression in ORNs of AD patients suggests that cell excitability associated with calcium ions and cell protective function against overload of intracellular calcium ions decline in these patients.

Adult↗

PubMed1996

Identification of pseudonormal transmitral flow pattern using color Doppler echocardiography.

The jet size of flow in color Doppler is dependent on both jet momentum and the compliance of the receiving chamber. Thus, the jet size of left ventricular (LV) late filling standardized by its jet momentum should reflect LV compliance. We investigated the feasibility of using color Doppler echocardiography to differentiate a pseudonormal from a normal transmitral flow pattern. We divided 37 patients with ischemic heart diseases who demonstrated a "normal" transmitral flow pattern into 2 groups according to their LV end diastolic pressure (LVEDP): a pseudonormalization group (LVEDP > or = 18 mmHg, 16 patients), and a normal group (LVEDP < 18 mmHg, 21 patients). We measured the maximum color Doppler jet length (L) and the peak velocity of transmitral flow during atrial contraction (Av). Filling volume (Q) was measured as the increase in LV volume during atrial contraction. A simplified jet momentum index (M) was obtained from Av x Q, and L/M was considered to reflect LV compliance. L/M was significantly lower in the pseudonormalization group that in the normal group (1.55 +/- 0.46 x 10(-3) vs 2.72 +/- 0.59 x 10(-3) p < 0.01). On the other hand, conventional Doppler variables such as isovolumic relaxation time and the deceleration time of early diastolic filling were not sufficient for discriminating between the 2 groups. In conclusion, color Doppler echocardiogram during atrial contraction was useful for differentiating a pseudonormal from a normal transmitral flow pattern.

Adult↗

PubMed1996

[A case report of Darling's classification Ib total anomalous pulmonary venous return with an unusual left pulmonary vein].

A radical correction involving Vargas's method and a direct anastomosis between the left pulmonary vein (PV) and left atrium (LA) was performed in a 29 day-old infant with supracardiac type Ib total anomalous pulmonary venous return (TAPVR) and an unusual form of the left PV. the left upper and lower PVs drained into a left "common" PV that was just behind the LA, and then into the right pleural cavity. The left common PV was located cephalad to the normal course and received blood from the right lower and upper PVs and drained into the supra-vena cava (SVC). The junction of the SVC and the right PV was slightly stenotic. Vargas's method is a useful technique for Darling's classification Ib TAPVR even in cases without the common PV situated behind the LA. But this patient had a left common PV and it was possible either to anastomose the common PV and LA directly or to perform Vargas's technique. We performed both procedures to prevent left PV obstruction (PVO). Cineangiography performed 2 months after surgery showed that a large amount of blood from the right and left PV drained into the LA through the common PV-LA route. These procedures, which create a dual PV channel, reduce the risk of PVO, so they are useful for radical correction of Darling's Ib type TAPVR.

Cardiac Surgical Procedures↗

PubMed1995

Isolation of temperature-sensitive mutants for mRNA capping enzyme in Saccharomyces cerevisiae.

The guanylyltransferase activity of mRNA capping enzyme catalyzes the transfer of GMP from GTP to the 5' terminus of mRNA. In Saccharomyces cerevisiae, the activity is carried on the alpha subunit of capping enzyme, the product of the CEG1 gene. We have isolated 10 recessive, temperature-sensitive mutations of CEG1; nine (ceg1-1 to ceg1-9) were isolated on a single-copy plasmid and the remaining one (ceg1-10) on a multicopy plasmid. The presence of ceg1-10 in multiple copies is essential for the viability of cells carrying the mutation, and a shift to the restrictive temperature resulted in rapid growth arrest of ceg1-10 cells, while growth rates of other mutants decreased gradually upon temperature upshift. Intragenic complementation was not observed for pairwise combinations of the mutations. Although the majority of the mutations occurred at the amino acid residues conserved between Ceg1 and the Schizosaccharomyces pombe homologue, none were located in the regions that are also conserved among viral capping enzymes and polynucleotide ligases. Guanylyltransferase activity of the mutant proteins as measured by covalent Ceg1-GMP complex formation was heat-labile. The availability of these mutants should facilitate studies of the structure-function relationships of capping enzyme, as well as the roles and regulation of mRNA capping.

Amino Acid Sequence↗

PubMed1995

Decrease in cell viability due to the accumulation of spermidine in spermidine acetyltransferase-deficient mutant of Escherichia coli.

Physiological functions of spermidine acetyltransferase in Escherichia coli have been studied using the spermidine acetyltransferase (speG) gene-deficient mutant CAG2242 and the cloned speG gene. The growth of E. coli CAG2242 in the defined M9 medium was normal in the presence and absence of 0.5mM spermidine. However, cell viability of E. coli CAG2242 at 48 h after the onset of growth decreased greatly by the addition of 0.5 mM spermidine. The amount of spermidine accumulated in the cells was approximately 3-fold that in the cells grown in the absence of spermidine. Transformation of the cloned speG gene to E. coli CAG2242 recovered the cell viability. Decreased in cell viability of E. coli CAG2242 was observed even when 0.5mM spermidine was added at 24 h after the onset of growth. The results indicate that accumulated spermidine functions at the late stationary phase of growth. The accumulation of spermidine caused a decrease in protein synthesis but not in DNA and RNA synthesis at 28 h after the onset of growth. The synthesis of several kinds of proteins was particularly inhibited. They included ribosome modulation factor and OmpC protein. Since the ribosome modulation factor is essential for cell viability at the stationary phase of growth (Yamagishi, M., Matsushima, H., Wada, A., Sakagami, M., Fujita, N., and Ishihama, A. (1993) EMBO J. 12, 625-630), the decrease in the protein was thought to be one of the reasons for the decrease in cell viability. The decrease in the ribosome modulation factor mainly occurred at the translational level.

Acetyltransferases↗

PubMed1995

Assessment of coronary artery distensibility by intravascular ultrasound. Application of simultaneous measurements of luminal area and pressure.

BACKGROUND: Atherosclerotic change in the coronary artery is associated with an impaired vessel wall distensibility. However, there are few data regarding the relation between vessel wall morphology and distensibility. Therefore, with intravascular ultrasound, we assessed coronary artery distensibility in angiographically normal coronary segments of humans. METHODS AND RESULTS: Data were analyzed at 35 angiographically normal coronary sites where circumferential or noncircumferential lesions were demonstrated by ultrasound in 22 patients (mean age, 55 years). After intracoronary injection of 500 micrograms nitroglycerin (NTG), coronary luminal area was measured with intravascular ultrasound (30 MHz, 3.5F to 4.3F, 1800 rpm). Intracoronary pressure was simultaneously measured with a 2F micromanometer-tipped catheter located at the left main coronary artery. The coronary distensibility index was calculated as 10-fold the ratio of luminal area change to intracoronary pressure change during a cardiac cycle. Another pressure-independent vascular stiffness index, beta, was derived by the following formula: beta = [ln(SBP/DBP)]/(dD/diastolic mean diameter), where SBP is systolic intracoronary pressure, DBP is diastolic intracoronary pressure, and dD is the difference between systolic and diastolic diameters. At the sites where luminal areas were measured, thickness of intima-media complex, defined as the distance between the intimal leading edge and the adventitial leading edge, was determined as an index of the severity of atherosclerosis. In seven segments, distensibility index was determined before and after NTG injection to examine the effect of NTG on coronary distensibility. In all examined sites, including circumferential and noncircumferential lesions, the luminal area was 12.6 +/- 5.0 mm2 during systole and 11.6 +/- 4.6 mm2 during diastole, and the calculated coronary distensibility index ranged from 0 to 0.83 mm2/mm Hg. The thickness of the intima-media complex ranged from 0.12 to 1.30 mm, suggesting the presence of various grades of atherosclerosis even in the absence of angiographic lesions. There was a poor inverse correlation between thickness of the intima-media complex and distensibility index (r = .19, y = -0.17x + 0.41, P = .29). However, when noncircumferential lesions were excluded for evaluation, there was a significant inverse correlation between them (r = .58, y = -0.50x + 0.72, P < .01). Under these conditions, the thickness of the intima-media complex also correlated with the value of beta (X10(-1), which ranged from 0.28 to 3.99 (r = .70). After NTG injection, coronary distensibility increased by an average of 71% in the segments with a thin intima-media complex, whereas it did not substantially change in those with a relatively thick intima-media complex. CONCLUSIONS: These results suggest that coronary distensibility is impaired in the coronary sites accompanying occult atherosclerosis, none of which can be detected by the conventional angiography. NTG can augment coronary distensibility in the segments without a markedly thickened intima-media complex. We suggest that thickness of the intima-media complex can contribute to determining the coronary distensibility in clinical settings.

Adult↗

PubMed1995

New method for evaluating left ventricular wall motion by color-coded tissue Doppler imaging: in vitro and in vivo studies.

OBJECTIVES: The aim of this study was to examine the accuracy and validity of a newly developed tissue Doppler imaging system in in vitro and in vivo studies. BACKGROUND: Because quantitative measurement of wall motion velocity in real time is still difficult by conventional echocardiography, we developed a new system for evaluating ventricular wall motion by analyzing Doppler signals from cardiac tissue. METHODS: We used a modified Doppler color imaging system, omitting the high pass filter to allow Doppler signals from cardiac tissue to enter the auto-correlator. Ultrasound carrier and pulse repetition frequencies were 3.75 MHz and 3.0 to 6.0 kHz, respectively. Under these conditions, the lowest measurable velocity was 0.2 cm/s. RESULTS: In the rotating sponge model, the measured velocity correlated well with the actual velocity (y = 0.97x + 2.17, r = 0.99). In clinical settings, the mid-ejection mean velocity at either endocardial or epicardial sites of the left ventricular posterior wall measured by M-mode tissue Doppler imaging correlated well with that measured by conventional M-mode echocardiography (y = 0.94x + 0.64, r = 0.99). During systole, in healthy subjects, the anterior left ventricular wall was color-coded blue and the posterior wall was color-coded red, whereas the akinetic regions associated with myocardial infarction showed no color throughout the cardiac cycle. The ventricular posterior wall excursion velocity, defined as the difference between velocities at the endocardial and epicardial sites, was significantly slower in patients with dilated cardiomyopathy (0.4 +/- 0.3 cm/s) than in normal subjects (2.0 +/- 0.6 cm/s). CONCLUSIONS: These results indicate that the present system accurately represents tissue velocity and can create two-dimensional color images that facilitate visual assessment of ventricular wall motion.

Adult↗

PubMed1995

Enhanced extrinsic innervation of nasal and oral chemosensory mucosae in keratin 14-NGF transgenic mice.

The role of nerve growth factor (NGF) in neurotrophic support for the extrinsic innervation of the nasal and oral mucosae was investigated in keratin 14 (K14) - NGF transgenic mice in which NGF was overexpressed in K14-synthesizing cells. K14 immunoreactivity was localized in the epithelial basal cells of the whisker pad skin, the hard palate, the floor of the ventral meatus, and the anterior tongue that are stratified squamous epithelia, and also in basal cells of the vomeronasal, olfactory, and respiratory epithelia that are non-stratified epithelia. In transgenic mice, NGF expression was identified and confined primarily to the basal cells of stratified epithelia. The nasal mucosae including the vomeronasal, olfactory, and respiratory mucosae, and the glands associated with the vomeronasal organ received a greater innervation of protein gene product 9.5-immunoreactive extrinsic fibers in transgenic animals than nontransgenic controls. An increased density of calcitonin gene-related peptide-immunoreactive extrinsic fibers was observed in the nonsensory epithelia of the vomeronasal organ, the olfactory sensory and respiratory epithelia in transgenic animals. Our results indicated that the hyperinnervation of the nasal and oral mucosae by extrinsic neurons is due at least partially to target-derived NGF synthesis and release by K14-expressing basal cells.

Animals↗

PubMed1995

Comparison of vessel wall morphologic appearance at sites of focal and diffuse coronary vasospasm by intravascular ultrasound.

Coronary vasospasm is manifested by either focal or diffuse pattern in clinical settings. To examine the differences in vessel wall morphologic appearance between the sites of focal and diffuse vasospasm, we studied 29 patients with chest pain at rest, during exertion, or both by intravascular ultrasound. By angiography, focal vasospasm with diameter reduction of 90% +/- 3% (mean +/- SD) was provoked by intracoronary ergonovine (0.01 to 0.04 mg) in 15 patients. Diffuse vasospasm with diameter reduction of 79% +/- 5% (NS) was provoked in seven patients, and the remaining seven patients served as the control group. By ultrasonography, a significantly thickened intimal leading edge with sonolucent zone was observed in 55 sites from 22 coronary arteries with either focal or diffuse vasospasms (0.61 +/- 0.32 mm), although these sites were normal or minimally narrowed by angiography. Seven segments from the control group exhibited a thin intimal leading edge with sonolucent zone (0.23 +/- 0.08 mm, p < 0.01). When the thickness of the intimal leading edge with sonolucent zone was compared between the abnormal sites with focal and diffuse vasospasm, this was significantly greater at focal spasm, 1.01 +/- 0.35 mm (n = 15), than that at diffuse spasm, 0.46 +/- 0.13 mm (n = 40, p < 0.01). At the sites with diffuse spasm, some of the lesions lay scattered along the coronary vessels, although the lesions were localized at the sites of focal vasospasm. These results indicate that atherosclerosis is present at sites with both focal and diffuse vasospasm even in the absence of angiographically significant coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

Coronary reactivity to nitroglycerin: intravascular ultrasound evidence for the importance of plaque distribution.

OBJECTIVES: This study was designed to assess the extent and timing of vasodilation after intracoronary administration of nitroglycerin using intravascular ultrasound. We also sought to relate the magnitude of nitroglycerin-induced dilation to the distribution of atherosclerotic plaque. BACKGROUND: Although previous angiographic studies have shown that nitroglycerin can dilate both normal and stenotic coronary arteries, it remains uncertain whether atherosclerotic vessels can respond to nitroglycerin to the same extent as normal arteries in the clinical setting. METHODS: We analyzed a total of 48 segments from 48 patients by means of a multielement 3.5F to 5.5F 20-MHz intravascular ultrasound system before and after intracoronary administration of nitroglycerin (250 micrograms). Videotaped images were digitized, and the lumen cross-sectional area was measured with an electronic cursor. In noncircumferential lesions, the perimeters of the normal and diseased portions were measured separately to compare the reactivity to nitroglycerin in each portion. RESULTS: Of 48 sites examined 14 were normal by ultrasound, and 34 revealed atherosclerotic lesions. In the 14 normal segments nitroglycerin produced a large increase in cross-sectional area (31 +/- 16% [mean +/- SD]) within 60 s after injection. In the 34 atherosclerotic segments, nitroglycerin-induced dilation was impaired, and the cross-sectional area increased only 12 +/- 8% (p < 0.01). In 15 of 34 atherosclerotic segments, a noncircumferential lesion was identified, and the cross-sectional area after nitroglycerin increased an average of 17 +/- 6%. In the remaining 19 sites, circumferential disease was present, and the cross-sectional area increased by only 8 +/- 7% (p < 0.05 vs. normal or noncircumferential atherosclerotic segments). In noncircumferential lesions, the increase in the perimeter of the normal portion of the wall was significantly greater (14 +/- 6%) than the increase in the diseased portion (5 +/- 3%, p < 0.05). CONCLUSIONS: These data indicate that vasoreactivity after nitroglycerin administration is reduced in segments with atherosclerosis by ultrasound. We suggest that nitroglycerin-induced vasodilation at the stenotic segments can be produced primarily by expansion of the nondiseased portion of the vessel wall.

Adult↗