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Biomedical subjects

F Yoshioka

Publications and source records attributed to F Yoshioka.

At least 19 recordsLinked to original sources
PubMed2001

Dynamic sonography of hepatic tumors.

OBJECTIVE: Our objectives were to propose and evaluate a dynamic sonography protocol for the characterization of hepatic tumors. SUBJECTS AND METHODS: The subjects were 107 patients with focal liver lesions that initially had been found on conventional sonograms. The final diagnoses for the lesions were hepatocellular carcinoma in 60 patients, cholangiocellular carcinoma in six, metastatic carcinoma in 24, hemangioma in 10, and focal fat-spared region in seven. The pulse inversion harmonic imaging mode and a galactose-based contrast agent (Levovist) were used. Dynamic sonography was designed to obtain vascular-phase (composed of the arterial phase and the portal phase) images of the focal lesion and liver-parenchymal-phase images of the whole liver in a series obtained after a bolus injection of the contrast agent. RESULTS: If the whole-tumor or mosaic enhancement patterns (arterial phase) and/or the reticular enhancement (parenchymal phase) are regarded as positive findings for hepatocellular carcinoma, the sensitivity, specificity, and positive predictive value of dynamic sonography in our study were 92%, 96%, and 96%, respectively. If a ring enhancement (arterial to portal phase) or a clear defect (parenchymal phase) or both are regarded as positive findings for cholangiocellular carcinoma or metastasis, the sensitivity, specificity, and positive predictive value were 90%, 95%, and 88%, respectively. If puddle enhancement (portal phase) is regarded as a positive finding for hemangioma, the figures for sensitivity, specificity, and positive predictive value were 60%, 100%, and 100%, respectively. Also, the tumors that showed no focal sign in the liver parenchymal phase were all benign lesions, such as hemangiomas or focal fat-spared regions. CONCLUSION: Dynamic sonography in a protocol combining pulse inversion harmonic imaging and an IV bolus injection of the contrast agent proved to be an effective tool in characterizing liver tumors.

Adult↗
PubMed1998

Value of contrast-enhanced color Doppler sonography in diagnosing hepatocellular carcinoma with special attention to the "color-filled pattern".

PURPOSE: The purpose of this study is to evaluate the effectiveness of contrast-enhanced color Doppler sonography in the diagnosis of hepatocellular carcinoma (HCC), with special attention to the value of a "color-filled pattern." METHODS: Contrast enhancement with Levovist was performed on 30 liver tumors, including 21 HCCs, as part of phase II and III clinical trials. Detection of a "feeding artery" or a "color-filled pattern" with color Doppler sonography was interpreted as a positive finding for HCC. Angiography was also performed. RESULTS: A feeding artery was detected in 9 HCCs before contrast enhancement and 20 HCCs after. A color-filled pattern was seen in 14 HCCs after enhancement. A feeding artery was seen in only 1 non-HCC tumor, and a color-filled pattern was not seen in any non-HCC. The sensitivity and specificity of a feeding artery for the diagnosis of HCC were 95% and 89%, values similar to those of hepatic angiography. The sensitivity and specificity of a color-filled pattern were 67% and 100%, respectively. CONCLUSIONS: Contrast enhancement increases the detectability of a feeding artery and improves the sensitivity of color Doppler sonography for diagnosing HCC. A color-filled pattern is a highly specific finding in the diagnosis of HCC.

Adult↗
PubMed1998

[Contrast enhanced color Doppler sonogram of liver tumors: a color-filled pattern in the late phase].

In the present report, a "color-filled pattern", the late phase effect in the intra-venous contrast enhanced color Doppler sonography is introduced, using SH/TA-508 as the contrast agent. This pattern is defined as an image of a tumor area filled with color in contrast to the surrounding liver. After contrast enhancement, the detectability of a "feeding artery" increased. And also "color filled pattern" appeared in 14 of the 21 hepatocellular carcinomas but none of the nine other liver tumors. In conclusion, contrast enhancement increases the detectability of a "feeding artery" and improves the sensitivity for HCC with color Doppler sonography. A "color-filled pattern" is also effective in the diagnosis of HCC because it requires no technical skill and shows high specificity.

Animals↗
PubMed1995

Effectiveness of galactose-based intravenous contrast medium on color Doppler sonography of deeply located hepatocellular carcinoma.

The purpose of this study is to examine the effectiveness of intravenously injectable sonographic contrast medium for color Doppler sonographic diagnosis of deeply located hepatocellular carcinoma. Subjects were 7 hepatocellular carcinomas, an adenomatous hyperplasia and a hemangioma located more than 7 cm below the abdominal surface. Levovist, a galactose-based sonographic contrast medium was injected through median cubital vein as a phase-two clinical study, and the pre- and post-enhanced color Doppler sonographic findings of these lesions were compared. The incidence of the positive findings for hepatocellular carcinoma increased from 29% (2/7) to 86% (6/7) of hepatocellular carcinoma after contrast enhancement. Positive findings were 0% in other cases even after enhancement. Levovist brought a certain improvement in the visualization of the tumor vessel by color Doppler sonography without any noteworthy side effects. Contrast enhancement was useful for the diagnosis of liver lesions suspected to be hepatocellular carcinoma by ordinary sonography, but could not be confirmed by color Doppler sonography.

Adult↗
PubMed1993

[Measurement of platelet thromboxane A2/prostaglandin H2 receptor in asthmatic patients].

To evaluate the characteristics of platelet TXA2/PGH2 receptors in patients with bronchial asthma, we performed radiobinding assay of gel-filtrated washed platelets obtained from 15 asthmatic patients and 8 normal adults using [3H]-labeled S-145, a TXA2/PGH2 receptor antagonist, as a radiolinged. Data were evaluated by Schatchard's analysis, and the dissociation constant (Kd), an index of the binding characteristic of receptors, and the maximum number of binding sites (Bmax) were calculated. Venous blood was simultaneously collected and was centrifuged, and platelet-rich plasma was prepared. The platelet aggregation rates induced by various concentrations of U-46619, a TXA2 analogue, were measured by Born's method (nephelometry), and the concentration that induced 50% of the maximum platelet aggregation (EC50) was calculated using a concentration-response curve. The Kd value did not differ between the asthmatic patients and normal controls. Some of the asthmatic patients showed a low EC50 and a high Bmax. EC50 was inversely correlated with Bmax. The number of platelet TXA2/PGH2 receptors was shown to be increased in some asthmatic patients.

Adult↗
PubMed1993

[Study on the inhibitory effect of AA-2414 on platelet aggregation and its clinical effect in asthmatic patients].

We previously reported that AA-2414, an eicosanoid receptor antagonist, inhibits platelet aggregation mediated by TXA2/PGH2 receptors in patients with bronchial asthma, but that the inhibitory effects differ among individuals. In this study, we measured the in vitro inhibition rate of platelet aggregation by AA-2414 using U-46619 as an aggregating agent in 22 asthmatic patients and classified them into Group A (showing an inhibition rate of 60% or more) and Group B (showing a rate of less than 60%). Subsequently, AA-2414 tablets (40 mg/day) were orally administered to both groups for 6 weeks, and the clinical effects were compared. A positive correlation was observed between the in vitro U-46619-induced platelet aggregation rate and the inhibition rate of aggregation by AA-2414. At the end of administration, marked inhibition of U-46619-induced platelet aggregation was observed in all patients. However, Group A showed a higher improvement rate of symptoms than Group B. Asthmatic patients can be classified into the groups showing good or poor platelet responses. The response may reflect reactivity to TXA2 in the local airway.

Adult↗
PubMed1991

Validation of single-photon emission computed tomography (SPECT) using thallium-201 in patients with lung cancer.

To evaluate the primary site, pulmonary hilar, and mediastinal lesions in patients with lung cancer, thallium-201 using single-photon emission computed tomography (SPECT) was used as a tumor agent. The study population consisted of 7 patients (5 men and 2 women), aged 57 to 82 years (mean 68). Tl-201 tomography imaged positive at the primary site in all patients with lung cancer. The images demonstrated the tumor and/or mediastinal lymph nodes that were greater than 2.0cm. In particular, each tomograms facilitated the identification of the Tl-201 increased uptake in proportion to primary site. The short waiting period after injection with Tl-201 clearly offers a major advantage over alternative tumor imaging agents, such as Ga-67 or radiolabeled monoclonal antibodies. Furthermore, Tl-201 SPECT may be useful to detect the tumor and/or mediastinal lymph nodes in patients with lung cancer.

Aged↗
PubMed1991

Assessment of cardiac function using radionuclide techniques--theory, technical considerations and clinical application.

The recent expansion of interventional cardiovascular techniques has stimulated the development of non-invasive cardiac studies, to evaluate the outcome of the interventional therapy. Radionuclide ventriculographic technique provides to quantify global left ventricular systolic/diastolic performance, and evaluate the regional left ventricular wall motion during rest or exercise. This concept was extended from the "bedside" to the ambulatory environment with the description of a battery powered device, the radionuclide ventricular function monitor. To assess the performance of cardiac function using radionuclide ventriculography to that using the ambulatory ventricular function monitor, the systolic and diastolic function were measured at rest in a series of healthy volunteers (n = 10) and in patients with cardiovascular disease (n = 23). Seventeen patients had coronary artery disease (CAD) with prior myocardial infarction, three patients had coronary artery disease, and three patients had dilated cardiomyopathy. The 23 patients manifested a wide variation in LV systolic function. The relationship between the multiple gated acquisition (MUGA)-ejection fraction and the ambulatory ventricular function monitor-ejection fraction correlated well (r = 0.90). As a complement to the radionuclide perfusion studies, cardiac blood pool imaging and radionuclide ventricular function monitoring allow for through non-invasive description of cardiac physiology and function in patients with various cardiac disorders.

Adult↗
PubMed1990

[Clinical study on the inhibitory effect of AA-2414 on platelet function in asthmatic patients].

We studied the effect of AA-2414, a TXA2 receptor antagonist, on platelet function in 12 asthmatic patients, 6 males and 6 females, whose mean age was 43.6 years. AA-2414 was orally administered to each patient at 20 mg/day for two weeks and then at 40 mg/day for the following two weeks. Platelet aggregation, plasma concentration of TXB2, and serum concentrations of AA-2414 and its metabolites were measured before and after the administration of each dose. Platelet aggregation induced by U-46619 (an analogue of PGH2), STA2 (a stable analogue of TXA2) and arachidonic acid with the administration of AA-2414 was significantly inhibited. The degree of this inhibition was proportional to the serum level of the drug. Plasma concentration of TXA2 tended to be lowered by administration of AA-2414, but it was not statistically significant. Eight (75.0%) of the 12 patients showed clinical improvement. In the cases where the drug was ineffective, the inhibition of platelet aggregation after administration of AA-2414 was less than in those cases where it was effective. We conclude that AA-2414 might exert its antiplatelet and antiasthmatic effects through antagonism of the TXA2 receptor. Investigation of the response to AA-2414 may be useful in assessing the clinical effect of this compound.

Administration, Oral↗
PubMed1989

Ectopic posterior lobe of the pituitary gland and intractable nocturnal enuresis in a case with pituitary dwarfism.

An 11 5/12-year-old girl with pituitary dwarfism had intractable nocturnal enuresis. Magnetic resonance imaging revealed pituitary stalk transection and the formation of an ectopic posterior lobe. The results of responses to dehydration, infusion of hyperosmolar NaCl solution, and 1-desamino-8-D-arginine vasopressin showed that the nocturnal enuresis in the present case was due to a partial vasopressin deficiency. We suggest that the ectopic posterior lobe is one cause of nocturnal enuresis.

Child↗
PubMed1986

Mass screening of blood pressure in school children: results of the Karatsu Study.

The purpose of this study was to determine the prevalence of persistent blood pressure elevation in school children. Mass screening of blood pressure was performed simultaneously with a cardiovascular health check in school children. Forty four hundred and eighty school children were selected as subjects for this study, consisting of 2289 first grade primary school students aged six and seven (group A), and 2191 second grade junior high school students aged thirteen and fourteen (group B). Of the 4480 students, 4031 were examined at the initial blood pressure screening. Three hundred and sixty students whose systolic and/or diastolic pressures were above the 95th percentile were recalled for a second examination. Three hundred and thirty one students were studied at the 2nd examination, and 69 students were listed for a third survey. 1.7% of the original subjects were examined at the final survey. At the first screening, mean blood pressures were 101.5 +/- 8.5/61.2 +/- 6.6 mmHg (mean +/- SD) for males and 100.3 +/- 8.3/60.9 +/- 6.5 for females in group A. In group B, blood pressures were 120.2 +/- 11.3/66.6 +/- 7.4 mmHg for males and 117.4 +/- 11.2/66.9 +/- 7.8 mmHg for females. This screening system, if incorporated into the school health program, is an effective and efficient method of screening for persistent blood pressure elevation in school children in Japan.

Adolescent↗
PubMed1986

[Unusual cardiac hypertrophy in neonates with congestive heart failure: report of three cases].

We experienced three cases of unusual cardiac hypertrophy of the right ventricle or interventricular septum with severe congestive heart failure in the neonatal period. One patient had congenital heart disease consisting of membranous tricuspid atresia, absent pulmonary valve, patent ductus arteriosus, left single coronary artery and a hypoplastic pouch-like right ventricle. Very marked cardiac hypertrophy was observed in the right ventricle and interventricular septum. Histologically, there was no appreciable disorganization of the cardiac muscle. The etiology of the unusual hypertrophy of cardiac muscle in this patient is uncertain. The other two patients had asymmetrical septal hypertrophy of the left ventricle evidenced by two-dimensional echocardiography. Cardiac catheterization was performed for these two patients. There was no evidence of congenital heart disease; however, one patient had a significant pressure gradient in the outflow tracts of the left and right ventricles. These two patients' faces appeared unusual and they had minor anomalies of their fingers and ears. This unusual cardiac hypertrophy associated with cardiac anomalies and minor anomalies of the face and extremities comprise a specific type of cardiomyopathy in neonates. This should be distinguished from hypertropic cardiomyopathy of older children and adults.

Cardiomegaly↗
PubMed1986

[Carnitine deficiency: a treatable cardiomyopathy].

This is a report of two brothers, six and five years of age, with systemic carnitine deficiency and cardiomyopathy, whose symptoms were improved after oral administrations of DL-carnitine. They had had progressive muscle weakness since three years of age. The elder brother's radiograph on admission showed cardiomegaly with a cardiothoracic ratio of 60%, and his electrocardiogram showed left ventricular hypertrophy and tall, peaked T waves in the precordial leads. The echocardiogram showed slight thickening of the cardiac muscle and decreased ejection fraction. Skeletal muscle biopsy specimens and sera were assessed for carnitine content. The skeletal muscle specimens revealed lipid storage myopathy, and the carnitine contents of the skeletal muscle and sera were both decreased. Myocardial biopsy for the elder brother revealed mitochondrial accumulation. Cardiomyopathy caused by carnitine deficiency is often fatal, but may be cured. Carnitine deficiency should be considered whenever a patient with cardiomegaly and progressive skeletal muscle weakness is encountered.

Cardiomyopathies↗
PubMed1985

[Marked right ventricular outflow obstruction in two children with hypertrophic cardiomyopathy].

Two children, aged one year and nine months, and six years, both with hypertrophic cardiomyopathy, presented as severe right ventricular outflow obstruction were presented. Initially, both of them were suspected of having heart disease because of precordial systolic murmurs. Their tentative diagnosis was pulmonary stenosis. Their apex cardiograms and carotid pulse waves were not diagnostic. Asymmetrical septal hypertrophy with systolic anterior motion of the mitral valve was identified by echocardiography in both cases. Cardiac catheterization revealed left ventricular outflow tract pressure gradients of 5 mmHg and 30 mmHg, respectively. The right ventricular peak systolic gradient was 100 mmHg and 82 mmHg and left ventricular end-diastolic pressure was 26 mmHg and 18 mmHg, respectively. Selective right and left ventricular angiocardiograms demonstrated severe right ventricular outflow obstruction, and hypertrophy of the interventricular septum. One of them underwent resection of the right ventricular outflow tract muscle, which showed histological findings characteristic of hypertrophic cardiomyopathy. This patient died suddenly at the age of 10 years. Infants or young children with hypertrophic cardiomyopathy often have associated predominant right ventricular outflow tract obstruction, progressive congestive heart failure, and death. Therefore, correct diagnosis and careful treatment are mandatory for proper management.

Cardiac Output↗
PubMed1985

[Anomalous origin of the right coronary artery from the pulmonary artery: report of a case].

An asymptomatic 5-year-old boy with anomalous origin of the right coronary artery from the pulmonary artery was reported. He was referred to us for evaluation of an apical continuous murmur. The chest radiograph, and electrocardiograms at rest and during exercise were unremarkable. This anomaly, whose echocardiographic findings have not been described before, were visualized first by two-dimensional echocardiography, and confirmed by coronary angiography. There have been some reports of sudden death occurring in patients with this rare congenital heart defect. We believe that careful follow-up study is indicated.

Child, Preschool↗