Biomedical subjects

T Morozumi

Publications and source records attributed to T Morozumi.

At least 37 records · Page 2Linked to original sources

PubMed1997

Quantification of systolic count increase in technetium-99m-MIBI gated myocardial SPECT.

UNLABELLED: This study was performed to clarify the validity of quantification of myocardial wall thickening by the count increase method using electrocardiography (ECG)-gated SPECT. METHODS: We performed a phantom study to examine the quantification of this method and to clarify the relationship between the changes of relative counts and objective size (such as myocardial wall) under various conditions. In addition, in volunteers, the percent count increase (%CI) was analyzed in left ventricular segments based on circumferential profile curve analysis by ECG-gated SPECT with 99mTc-MIBI (methoxyisobutyl-isonitrile), and it was compared with the regional systolic wall thickness (%Th) assessed by echocardiography during low-dose dobutamine infusion. RESULTS: In our phantom study, the relative count changes were correlated linearly with the object size only within less than 20 mm. Recovery coefficient curves were influenced by acquisition parameters such as type of collimator, diameter of camera rotation, counts and photon scattering. In ECG-gated SPECT, the %CI value was increased gradually at each stage after dobutamine infusion, in relation to the increase of the %Th seen on echocardiography, although there are significant large deviations between these two parameters. CONCLUSIONS: In this study, quantitative analysis based on the %CI in ECG-gated SPECT may underestimate regional wall thickening. These data should be considered in the evaluation of the %CI as an index of myocardial function.

Adult↗

PubMed1996

Prognosis of hypertrophic cardiomyopathy: assessment by 123I-BMIPP (beta-methyl-p-(123I)iodophenyl pentadecanoic acid) myocardial single photon emission computed tomography.

123I-BMIPP (beta-methyl-iodophenyl pentadecanoic acid) has shown unique properties for potential use in assessing myocardial metabolism. Previous basic and clinical studies demonstrated that the disturbances of myocardial metabolism precede the occurrence of myocardial perfusion abnormalities by using 201Tl in hypertrophic myocardium. The present study was therefore undertaken to determine whether or not 123I-BMIPP myocardial SPECT is useful in predicting the prognosis of hypertrophic cardiomyopathy (HCM) in 65 patients in 6 facilities. There were 33 patients with non-obstructive HCM, 12 with obstructive HCM, 12 with apical HCM and 8 with dilated-phase HCM. Fasted patients at rest received an intravenous injection of 111 MBq of 123I-BMIPP. Twenty to thirty minutes later, myocardial SPECT was carried out. The BMIPP severity score (BMIPP SS) was evaluated semiquantitatively by using representative short axial SPECT images. We followed up the incidence of cardiac events for a mean period of 3.0 +/- 0.6 years. Cardiac events occurred in 13 patients. Of these, 11 developed heart failure and 6 died (4 from heart failure and 2 from sudden death). The BMIPP SS in the dilated-phase HCM was significantly lower than that for the nonsurvivors. The BMIPP SS was particularly high in patients with fatal heart failure. Furthermore, there was a close negative correlation between the BMIPP SS and percent fractional shortening measured by echocardiography (r = -0.49). Finally, the mortality over the three years increased according to the extent of the BMIPP SS. In conclusion, these results indicate that BMIPP SS is useful in evaluating the severity of HCM. We conclude that 123I-BMIPP is a valuable metabolic tracer in predicting the outcome of HCM.

Adult↗

PubMed1996

Myocardial integrated ultrasonic backscatter in patients with old myocardial infarction: comparison with radionuclide evaluation.

The purpose of our study was to clarify whether the abnormalities in integrated backscatter may be used to assess myocardial viability in patients with old myocardial infarction by comparing these integrated backscatter parameters with conventional radionuclide and echocardiographic estimates of myocardial viability. Two myocardial integrated backscatter parameters, the magnitude of cyclic variation in integrated backscatter and the myocardial integrated backscatter calibrated with the power of Doppler signals from the blood along the same ultrasound beam (calibrated myocardial integrated backscatter), were measured in 21 normal persons and 33 patients with old anteroseptal myocardial infarction. Calibrated myocardial integrated backscatter was higher and the magnitude of cyclic variation in integrated backscatter was lower in the infarct septum compared with the septum of normal subjects. Percent thallium uptake, as assessed in scintigraphic images taken at rest or after reinjection, correlated well with the calibrated myocardial integrated backscatter (r = -0.72, p < 0.01) and more weakly but significantly with the magnitude of cyclic variation in integrated backscatter (r = 0.55, p < 0.05) in 16 of 33 patients. The measurement of calibrated myocardial integrated backscatter, in addition to the magnitude of cyclic variation of integrated backscatter, may likely be valuable in the noninvasive assessment of myocardial viability.

Adult↗

PubMed1996

Macrolide susceptibility of Mycoplasma hyorhinis isolated from piglets.

Twenty strains of Mycoplasma hyorhinis were investigated for their in vitro susceptibilities to 15 antimicrobial agents by broth and agar dilution methods. Two of the 20 field strains showed low susceptibility to 14- and 16-membered macrolide antimicrobial agents tested. The two field strains were considered inducibly resistant to macrolides.

Animals↗

PubMed1996

Mycoplasma hyorhinis infection levels in lungs of piglets with porcine reproductive and respiratory syndrome (PRRS).

The infection levels of Mycoplasma hyorhinis, M. hyopneumoniae and M. hyosynoviae in the lung of piglets were examined in relation to porcine reproductive and respiratory syndrome (PRRS). These animals consisted of 43 PRRS piglets with PRRS, 2 piglets infected with PRRS virus but symptom-free, and 10 control piglets free of PRRS virus and its antibody. M. hyorhinis was isolated from 40 of the 43 PRRS piglets, from 1 of the 2 latent infected piglets and from 3 of the 10 control piglets. The number of M. hyorhinis isolated from the lungs of PRRS piglets was more than 10(5) CFU/g, but those isolated from the latent infected piglets and the control piglets were less than 10(3) CFU/g. In addition to this, Haemophilus parasuis and Pasteurella spp. were frequently isolated from the piglets with PRRS (51.2% and 25.6%, respectively). On the other hand, M. hyopneumoniae was isolated from only 4 of 55 piglets tested, and M. hyosynoviae was not isolated. M. hyorhinis was also detected directly in the lung emulsion samples from almost all the PRRS piglets using a polymerase chain reaction-based method.

Animals↗

PubMed1996

In vitro susceptibility of Mycoplasma hyosynoviae and M. hyorhinis to antimicrobial agents.

Fifty-four Japanese strains of Mycoplasma hyosynoviae isolated from porkers during 1980 to 1995, and 107 Japanese strains of M. hyorhinis isolated from piglets with respiratory disease during 1991 to 1994 were investigated for the in vitro activities of 13 antimicrobial agents [josamycin, tylosin, spiramycin, kitasamycin, erythromycin, lincomycin (LCM), kanamycin (KM), chloramphenicol (CP), thiamphenicol (TP), tiamulin (TML), oxytetracycline (OTC), chlortetracycline (CTC), and enrofloxacin (ERFX)] by the agar dilution method. Of the drugs tested TML showed the highest activity with minimum inhibitory concentration (MIC) of 0.013 to 0.1 microgram/ m/ (MIC90; 0.05 microgram/ml) against strains of M. hyosynoviae, and 0.2 to 0.78 microgram/ml (MIC90; 0.39 microgram/ml) against strains of M. hyorhinis. ERFX, LCM, most of the 16-membered macrolide antibiotics and tetracyclines also showed low MICs against both mycoplasma species. The susceptibility of KM, CP and TP to the mycoplasmas was considered to be of a secondary grade. Two of 54 strains of M. hyosynoviae, and 11 of 107 strains of M. hyorhinis showed resistance to all 14- and 16-membered macrolide antibiotics tested. Tetracyclines (OTC and CTC) showed a relatively broad MIC distribution from 0.1 to 6.25 micrograms/ml against the M. hyosynoviae strains tested. All of the strains isolated during 1980 to 1984 were susceptible at the concentration of 0.78 microgram/ml or less (MIC90; 0.78 microgram/ml) to OTC and 1.56 micrograms/ml or less (MIC90; 1.56 micrograms/ml) to CTC, while the susceptibility of strains isolated recently, during 1994 to 1995, was more than 0.78 microgram/ml (MIC90; 3.13 micrograms/ml) to OTC, and more than 1.56 micrograms/ml (MIC90; 6.25 micrograms/ml) to CTC.

Animals↗

PubMed1996

A simple preparation of mycoplasmal DNA template for PCR from biological samples using effective surfactants.

To prepare mycoplasmal DNA template for PCR from biological samples rapidly and easily, surfactants which can solubilize cell membranes effectively were investigated. 3-[3-Cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) was considered an effective surfactant. This surfactant could solubilize mycoplasma cell membrane without suppressing the polymerase reaction. In addition, proteinase K treatment played an important role in preparing mycoplasmal DNA template from a simulated biological sample. It was therefore considered that a combination of proteinase K- and CHAPS- added lysis buffer would be more useful in preparing mycoplasmal DNA template. We could detect PCR products by using the lysis buffer with a simulated lung emulsion sample containing mycoplasma organisms at 10(4) CFU per gram.

Animals↗

PubMed1996

Pathogenicity of Haemophilus parasuis serovars 4 and 5 in contact-exposed pigs.

The pathogenicities of Haemophilus parasuis strains SW124 (serovar 4) and Nagasaki (serovar 5) were examined by contact-exposure of specific pathogen-free (SPF) pigs. Ten pigs were divided into three groups. Two of four pigs in the first group were inoculated intranasally (IN) with 2 x 10(8) CFU of strain SW124, and the other two pigs were mingled with these IN-exposed ones. All the four pigs were subclinically infected in this group. The four pigs of the second group were likewise exposed to strain Nagasaki (two IN-inoculated pigs with 3 x 10(8) CFU of strain Nagasaki). All four pigs in this group died of Glässer's disease. Two pigs kept as controls showed neither abnormality nor positive H. parasuis isolation.

Animals↗

PubMed1996

Genetic properties of Mycoplasma mycoides subspecies mycoides LC strains isolated from a goat in Japan in 1991.

Field isolated Mycoplasma strains LG1 and SF1 were isolated from the lung and leg joint fluid of a goat, respectively in Japan in 1991. These strains were closely related and had the following biochemical properties: glucose was metabolized, arginine and urea were not hydrolyzed, tetrazolium was reduced, phosphatase produced, and casein and coagulated serum were digested. Serologically, these strains cross-reacted with three Mycoplasma species [M. mycoides subsp. mycoides (Mmm), M. mycoides subsp. capri, and M. sp. Group 7]. From the above results, the field isolates were considered to be Mmm. In addition, DNA-DNA relatedness between the field isolates and other Mycoplasma species called the "mycoides cluster" was determined, and a recently developed PCR method was also used for mycoplasmal identification. From these results, the field isolates were identified as Mmm LC type.

Animals↗

PubMed1996

Abnormal iodine-123-MIBG images in healthy volunteers.

We have encountered two healthy volunteers with significant reductions of myocardial [123I]MIBG (metaiodobenzylguanidine) uptake and rapid clearance. In one of these subjects (a 31-yr-old man), we performed additional examinations to clarify the mechanism of the abnormal myocardial MIBG uptake. There was no abnormality on orthostatic test, maximal exercise test (bicycle ergometer) or in plasma norepinephrine concentration. Nevertheless, power spectral analysis (PSA) of heart rate variability revealed that the percent low frequency component (%LF), an index of sympathetic nerve activity, was increased. Furthermore, [123I]MIBG scintigraphy after oral administration of an alpha 2 agonist (guanabenz acetate; 4 mg) demonstrated that myocardial uptake and clearance of MIBG returned to normal, as did the %LF. These results suggest that reduced uptake and rapid clearance of myocardial MIBG in this subject was strongly related to the increased release of norepinephrine from sympathetic nerve terminals due to augmented sympathetic activity. This subject illustrated that unsuspected, subclinical variants of normal or abnormal sympathetic functions may pose a diagnostic pitfall in interpretating myocardial MIBG images.

3-Iodobenzylguanidine↗

PubMed1995

Myocardial metabolism of 123I-BMIPP in patients with hypertrophic cardiomyopathy: assessment by radial long-axis SPET.

To elucidate the metabolism of free fatty acid in the myocardium of hypertrophic cardiomyopathy (HCM), SPET was performed with 123I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP), an analogue of free fatty acid, and with 201Tl in nine patients with HCM and eight healthy volunteers who acted as controls. For quantitative analysis of the apical area, a radial long-axis tomogram was reconstructed every 6 degrees after short-axis tomography. The relative regional uptake (RRU, %) in each segment was obtained by normalizing to the maximal value among all segments. The 3-h washout rate was calculated both for BMIPP and for 201Tl. The ratio of the RRU of BMIPP to that of 201Tl was significantly lower in the apical and antero-septal regions compared with other walls (P < 0.01) in the patients with HCM, whereas uptake of both BMIPP and 201Tl in the controls was homogeneous and there was a significant correlation between them. The coefficient of variation (CV) in all segments in the HCM patients was significantly higher (P < 0.01) than that of the controls both BMIPP and 201Tl, indicating inhomogeneous uptake of BMIPP in the HCM patients. The washout rate of BMIPP over 3 h was significantly higher in the patients with HCM (mean +/- S.D. 26.3 +/- 7.3%) than the controls (18.3 +/- 7.5%, P < 0.05). The ratio of segmental washout rate of BMIPP to that of 201Tl in the HCM patients was increased, especially in the septum and apex.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Serotypes and antimicrobial susceptibility of Actinobacillus pleuropneumoniae isolated from piglets with pleuropneumonia.

Minimal inhibitory concentrations (MICs) of 20 antimicrobial agents were determined for 67 field strains of Actinobacillus pleuropneumoniae isolated from the lungs of piglets with pleuropneumonia during the period 1992 to 1994, in Japan. Of these 67 strains, all 29 strains that were identified as serotypes 1 and 7 were resistant to chloramphenicol and tiamphenicol, whereas all of those identified as serotypes 2, 5 and 8 were susceptible to these antibiotics. Furthermore, 20 of 23 streptomycin-resistant strains were serotype 1, while, only 3 strains were serotype 2. These results suggest that the different serotypes of A. pleuropneumoniae vary in terms of antimicrobial-resistance.

Actinobacillus Infections↗

PubMed1995

Effect of physical defenses of the respiratory tract on the development of pneumonia in pigs inoculated endobronchially with Actinobacillus pleuropneumoniae.

Seven pigs inoculated endobronchially with Actinobacillus pleuropneumoniae (App) serotype 1 developed acute and subacute necrotizing pleuropneumonia. When treated with high doses of atropine (0.25 mg per kg) and/or xylocaine spray using a bronchoscope, which suppressed mucus secretion and ciliary activity, the pigs showed severe pleuropneumonia and 2 treated pigs died within 36 hr after inoculating 320 colony forming units (CFU)/2ml of App serotype 1. Histopathologically, their lungs had alveolar and interlobular edema and intravascular fibrinous thrombosis. In the surviving pigs, the lymph nodes had App antigens in the germinal centers corresponding closely with activated follicular dendritic cells and increased in the number of IgG- and IgM-containing cells. The bacterial antigens were also observed as small sized granules in the cytoplasm of bronchoalveolar macrophages. These findings suggest that the attachment of App to the mucosal surface may be crucial in the development of pneumonic lesions.

Actinobacillus Infections↗

PubMed1995

[Experience with mild exercise 123I-BMIPP myocardial imaging in two cases of ischemic heart disease].

During mild to moderate ischemia, glycolytic flux is enhanced and free fatty acid uptake is reduced in proportion to the reduction in mitochondrial metabolism. We considered that mild exercise may induce the reduction of 123I-BMIPP, reflecting myocardial fatty acid metabolism, in ischemic myocardium compared to normal myocardium. Therefore, mild exercise 123I-BMIPP myocardial imaging was carried out to detect myocardial ischemia in 2 cases of ischemic heart disease. Mild exercise was performed using a bicycle ergometer with 25-50 W loading. At seven minutes before cessation of exercise, 111 MBq of 123I-BMIPP was injected. Case 1 was a 12 year-old boy with Kawasaki's disease. The study showed a reduction of mild exercise 123I-BMIPP uptake in the anteroseptal wall. In contrast, stress 201T1 myocardial imaging did not show perfusion defect in the anteroseptal wall. Case 2 was a 64 year-old female with triple vessels disease. Mild exercise 123I-BMIPP myocardial imaging showed similar with those of stress 99mTc-sestamibi. We conclude that mild exercise 123I-BMIPP myocardial SPECT may be a sensitive method to detect myocardial ischemia.

Child↗

PubMed1994

Detection of coronary artery disease by dynamic planar and single photon emission tomographic imaging with technetium-99m teboroxime.

To test the clinical significance of technetium-99m teboroxime regional myocardial clearance in the detection of coronary artery disease, 25 patients underwent dynamic planar or single-photon emission tomographic (SPET) myocardial imaging with 99mTc-teboroxime after exercise and again 2 h later at rest. All patients underwent both thallium-201 exercise and redistribution SPET and coronary arteriography. The early phases of exercise 99mTc-teboroxime myocardial clearance determined by dynamic planar imaging showed a significant difference between normal and post-stenotic myocardial regions (clearance rate constant k: 0.047 +/- 0.005 min-1 versus 0.034 +/- 0.003 min-1, P < 0.001). Reflecting this "differential clearance" between myocardial regions, an early redistribution-like phenomenon was observed in a significant number of myocardial segments by comparing serially acquired post-exercise 99mTc-teboroxime SPET images. These results indicated that the analysis of 99mTc-teboroxime myocardial clearance was of potential use in the detection of coronary artery disease, yielding additional information to that provided by the tracer distribution analysis. Although the early redistribution-like phenomenon of 99mTc-teboroxime could be the source of underestimation of ischaemia if acquisition of the initial post-exercise image were delayed, it could also prove useful in the early differentiation of ischaemia from scar because when the phenomenon was observed in delayed post-exercise images, the rest study could be omitted under some circumstances.

Coronary Angiography↗

PubMed1994

Isolation of porcine reproductive and respiratory syndrome (PRRS) virus from Heko-Heko disease of pigs.

Porcine reproductive and respiratory syndrome (PRRS) virus was isolated at high frequency from the sera and lungs of pigs affected with Heko-Heko disease. In addition, a considerable amount of Mycoplasma hyorhinis (Mhr) was also isolated from the lungs. Inoculation of gnotobiote pigs with the first isolate of PRRS virus resulted in the reproduction of proliferative and interstitial pneumonia. The virus was recovered from the inoculated pigs for long periods. Superinfection with PRRS virus and Mhr appeared to produce more serious pneumonia than inoculation with PRRS virus alone. In this study, the presence of PRRS virus was confirmed in Japan, and the PRRS virus was considered as being the most important pathogen for Heko-Heko disease.

Animals↗

PubMed1994

Pathologic observations of pigs intranasally inoculated with serovar 1, 4 and 5 of Haemophilus parasuis using immunoperoxidase method.

Nineteen, 7- to 13-week-old pigs were inoculated intranasally with different strains of Haemophilus parasuis (serovar 1, 4 and 5), and the pathological lesions induced by each strain were compared. Eleven of thirteen pigs inoculated with either strain Nagasaki (serovar 5) or No. 4 (serovar 1) died between days 1 to 6 after inoculation, and had septicemic lesions, meningitis, or polyserositis. One of six pigs inoculated with strain SW124 (serovar 4) died with polyserositis, another one recovered after illness, and the remaining four pigs remained in good health. Five of the septicemic pigs had thrombi at many organs. Endotoxin was detected in the plasma of 10 pigs in the acute stage of infection. Using the immunoperoxidase technique, H. parasuis antigen was detected in lesions of infected pigs. In the serosal lesions the bacterial antigen was found mainly in the cytoplasm of infiltrating neutrophils and macrophages and appeared as degenerated bacteria and/or lytic bacterial material in dilated phagosomes. Many of the bacteria in the blood vessels of pigs with septicemic lesions were also degenerated. Although H. parasuis was reisolated from nasal secretions of infected pigs, the bacterial antigen could not be detected in the nasal cavities of these pigs. No lesions were observed in the parenchyma of the lung. However, H. parasuis antigen was detected in the tonsil of infected pigs.

Administration, Intranasal↗

PubMed1994

Isolation and serological characterization of porcine reproductive and respiratory syndrome (PRRS) viruses from pigs with reproductive and respiratory disorders in Japan.

Three porcine reproductive and respiratory syndrome viruses (PRRSVs) were successfully isolated from stillborn piglets and fattening pigs derived from different herds affected either with an epizootic reproductive failure or a severe chronic respiratory distress in Japan. The isolates were reacted with antisera against both European (Lelystad virus) and American (strain 46448) PRRSVs in indirect immunofluorescence (IIF). However, cross immunoperoxidase monolayer assay revealed the close serological relationships between the Japanese isolates and American PRRSV, but not between the Japanese isolates and the European PRRSV. The data of preliminary serological survey with IIF technique showed a high frequency of antibody positive pigs against both Japanese isolate and the American PRRSV, whereas a low frequency of antibody positive pigs against the European PRRSV, on herds which have had clinical episodes of PRRS-like diseases. These results indicate that PRRSVs are prevalent in Japan, and suggest that the antigenicities of the prevalent PRRSVs are more closely related to those of the American than the European PRRSVs.

Animals↗