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Biomedical subjects

T Hirata

Publications and source records attributed to T Hirata.

At least 505 records · Page 28Linked to original sources
PubMed1980

Left atrial ball thrombus diagnosed by two-dimensional echocardiography.

The diagnosis of the ball thrombus in the left atrium has been very difficult by conventional clinical techniques. In the present case, two-dimensional echocardiography successfully demonstrated a spherical tumor moving in unpredictable directions in the left atrium. M-mode echocardiography did not clearly identify the tumor because of the limited visual width and spatial orientation of the technique; however, simultaneous recordings of the M-mode echocardiogram with phonocardiogram, carotid pulse wave, and electrocardiogram provided some diagnostic clues to the occlusive left atrial tumor. In the absence mitral valve occlusion by the tumor, a logarithmic correlation between the ejection time and the preceding R-R interval, and a negative lines correlation between Q to the first sound interval and the preceding R-R interval were found. In the beat following the appearance of the tumor in the mitral orifice, the sudden shortening of the ejection time and the prolongation of Q to the first sound interval were noted. Both of these findings are indirect evidence of decreased left ventricular filling associated with an elevated left atrial pressure resulting from the sudden mitral orifice obstruction by the tumor. Detailed analysis of the data obtained by the conventional noninvasive techniques could provide critical clues for the diagnosis of the occlusive left atrial tumor.

Blood Coagulation↗
PubMed1980

Correlation of early neurologic outcome and CT findings in neonatal brain hypoxia and injury.

Ninety cranial computed tomography scans were analyzed in 56 high risk neonates (30 premature and 26 term). Neurologic follow-up averaging 18 months in length was obtained. Four types of intracranial hemorrhage were seen: subdural (with three subtypes), germinal matrix--intraventricular, primary subarachnoid, and cerebellar. The four types differ in age of occurrence, mechanism, and prognosis. Mild periventricular low density was present in most of the neonates and did not correlate with future neurologic deficit. Severe periventricular leukomalacia (16%) and cortical low density zones (12%) at 40 weeks did correlate with abnormal motor and mental development.

Brain Injuries↗
PubMed1980

Attenuated response to insulin in very low birthweight infants.

Four hyperglycemia very low birthweight (VLBW) infants were given a constant infusion of insulin with parenteral alimentation in order to improve glucose tolerance. After an initial 45% decrease in serum glucose, intolerance recurred within hours to days despite delivery of as much as 16 units/kg/hour or regular insulin. Resulting serum insulin levels were as high as 72,000 microU/ml. It is suggested that insulin "resistance", instead of insulin deficiency, may be responsible for glucose intolerance in some infants.

Glucose↗
PubMed1980

Detection of flail aortic valve in bacterial endocarditis with real-time two-dimensional echocardiography. A case report.

This report describes a case with flail right and noncoronary cusps due to bacterial endocarditis, diagnosed with real-time two-dimensional echocardiography. Real-time two-dimensional phased array sector scanner demonstrated 2 cugdel-shaped lesions in the region of the left ventricular outflow tract through the aortic root, pendulating upward and downward floating along the blood stream. This study shows that the real-time two-dimensional echocardiography is a very useful noninvasive tool in the early diagnosis of flail aortic valve.

Adult↗
PubMed1980

The change in the left atrial dimension during diastole. Echocardiographic assessment of mitral stenosis.

The change in the left atrial dimension during diastole was examined in patients with mitral stenosis using echocardiography. The left atrial emptying fraction (LAEF), defined as the ratio of enddiastolic dimension to endsystolic dimension of the left atrium, was 0.65 +/- 0.03 (mean +/- SE) for normal subjects, 0.86 +/- 0.01 for low grade mitral stenosis, and 0.92 +/- 0.01 for high grade stenosis. The LAEF correlated well with mitral valve area index (r = -0.70), but the correlation between E-F slope of the anterior mitral leaflet and mitral valve area index was less significant (r = 0.48). In patients who received mitral valve replacement the LAEF and the left atrial dimension significantly improved. The left atrial emptying fraction is an easily obtainable and reliable index to estimate the severity of mitral stenosis, even in patients who have undergone mitral valvular surgery.

Adult↗
PubMed1980

Simultaneous closure of the tricuspid and mitral valve in Ebstein's anomaly.

Echocardiographic studies of a 23-year-old man with Ebstein's anomaly and type B Wolff-Parkinson-White syndrome showed almost simultaneous closure of the tricuspid and mitral valve. After administration of edrophonium chloride, the tricuspid valve closed 20 msec earlier than the mitral valve. However, the closure of the mitral valve preceded that of the tricuspid valve after administration of ajmaline and atropine sulfate by 90 msec and 60 msec, respectively, concomitant with obliteration of preexcitation. From these observations, the simultaneous closure of the tricuspid and mitral valve of this case appears to depend on the preexcitation of the right ventricle.

Adult↗
PubMed1980

[Intracerebral germinoma developing in the right basal ganglia--report of a case followed up by CTscan and review of the literature (author's transl)].

Recently, a case of intracranial germinoma in the right basal ganglia was experienced in our department. He was a 14-years old boy with left motor hemiparesis. On repeated CT studies (7 times), developmental process of the tumor was observed for about 2 years. The tumor developed from the right putamen and invaded toward it's neighboring area (right basal ganglia, thalamus and hypothalamus). As the tumor grew larger, multiple cysts were formed in the tumor tissue and dislocation of ventricles occurred. On 21 December 1978, right temporal craniotomy was performed and a piece of the tumor was removed. It's tissue was diagnosed as germinoma by pathohistological examination. As the effect of postoperative 60Co irradiation and chemotherapy (Vicristine, CCNU), tumor stain (high density area) on CT scann disappeared and remained only as a well margined low density area. On CT scan in September 1979, recurrence sign was not noted. Clinical features of the germinoma located in the basal ganglia has not been well known, because of it's rarity. As a result of the survey of 7 cases reported in the Japanese literature and our case, it has been made clear that most of them are characterized by motor hemiparesis in the early stage, not accompanied by intracranial hypertension.

Adolescent↗
PubMed1979

Perinatal listeriosis--a review of twelve patients.

From July, 1974 to February, 1978, we managed 12 infants with listeriosis. This infection presented in two distinct forms: an early-onset type (nine patients), often representing a congenital infection following maternal illness, and a late-onset type in which the patient presented with meningitis (three patients). Of our nine infants with early-onset disease, three died, three developed permanent sequelae, and only three were normal at follow-up. Appropriate early management in the perinatal period may improve the outlook in this condition. Affected infants were often premature and had pneumonia, rash, and hepatosplenomegaly at birth. Prenatal clues to the diagnosis included maternal fever, abdominal pains, and leukocytosis with meconium staining of the preterm amniotic fluid. Examination of gastric aspirate at birth showed gram-positive coccobacilli. Antibiotic therapy should be started prenatally and continue for three weeks after birth to prevent recurrences of the late-onset type. This late-onset disease presented as meningitis after the second week of life and responded well to antibiotics. Our three patients recovered without sequelae.

Female↗
PubMed1979

Echocardiographic findings of large patent ductus arteriosus in the very low birthweight infant before and after treatment with indomethacin.

17 very low birthweight infants (mean birthweight 850 g) with large patent ductus arteriosus (PDA) were studied by echocardiography before and after treatment with indomethacin. Before treatment left heart dimensions were increased suggesting large left-to-right shunt. Echographic measurements of augmented left ventricular (LV) contraction could be attributed to increase in preload, and reduction in afterload in PDA. After indomethacin, in infants showing clinical response, left heart dimensions returned rapidly to normal and LV contraction became normal or reduced. Two infants had reduced LV contraction with persistent pulmonary oedema suggesting LV failure. In contrast, infants showing no clinical response to the drug also had no significant changes in echographic measurements. Right ventricular systolic time intervals (RPEP/RVET) did not alter after indomethacin treatment in either group, suggesting that the drug does not increase pulmonary vascular resistance.

Blood Pressure↗
PubMed1979

Early closure of the tricuspid valve in a case of Ebstein's anomaly with type B Wolff-Parkinson-White Syndrome.

Echocardiographic studies of a 19-year-old female with Ebstein's anomaly and type B Wolff-Parkinson-White syndrome showed an earlier closure of the anterior tricuspid leaflet (ATL) than of the anterior mitral leaflet (AML), contrary to the previous reports. The interval between the closure of the ATL and the AML was 20 msec and 30 msec, respectively, before and after administration of edrophonium chloride. However, closure of the AML preceded that of the ATL after administration of atropine sulfate and during supraventricular tachycardia by 10 msec and 60 msec, respectively, concomitant with the shortening of the duration of the QRS complex. We conclude that early closure of the ATL may depend on preexcitation of the right ventricle.

Adult↗
PubMed1979

Electron microscopic observations of intracytoplasmic membrane systems and cell division in Mycobacterium lepraemurium.

The fine structures and the interconnections between the intracytoplasmic membrane systems and cell division of murine leprosy bacilli in liver tissue from mice infected intraperitoneally with Mycobacterium lepraemurium, Hawaiian strain, were studied in ultrathin serial sections at the electron microscopic level. Intracellular membranous organelles (mesosomes) were seen as vesicular, tubular and/or lamellar structures. The formation of mesosomes appeared to be initiated by invagination and/or folding of the cytoplasmic membrane. A few dividing bacilli were observed. The lateral extension and the centripetal growth of the septal wall seemed to result from the original development of cytoplasmic membrane occurring at or near the leading edge of the nascent septum. After the septum formation was completely accomplished, the separation of two new daughter cells is assumed to occur. The mesosome was associated with the newly formed cytoplasmic membrane (septal wall). It was shown that both the cytoplasmic membrane and the mesosome played an important part in septum formation.

Animals↗
PubMed1979

PPD-induced immunoglobulin production in human peripheral blood lymphocytes. I. Necessary conditions for inducing the response.

The ability of PPD to induce Ig production in human PBL was investigated. PPD proved to be a good B cell activator for inducing polyclonal Ig production in PBL from healthy Japanese. Comparative studies of this response with PWM-induced Ig production showed that the cellular mechanisms involved in the two responses were different. First, PBL from an atypical individual with a deficient IgM production to PWM responded normally to PPD with IgM production as well as IgG production. Secondly, in IgG production, the effects of the two mitogens (PPDand PWM) were additive. An analysis of the cellular requirements in PPD-induced Ig production clearly demonstrated that T cells played a role in this response as well as in the PWM-induced response. However, the head-to-head comparative study on the titration curves of helper T cells in the two responses showed that PWM-induced helper activity was 2 to 5 times more effective than PPD-induced helper activity. Moreover, PPD-induced helper activity was shown to be more sensitive to ionizing radiation than was PWM-induced helper activity. Thus, this system of PPD-induced Ig production may provide a useful tool for understanding the human antibody production system as well as the PWM-induced response.

B-Lymphocytes↗
PubMed1979

Effects of concanavalin A-induced cells on the proliferative response of T cells. Concanavalin A-induced suppressor and amplifier cells to the proliferative response of human T cells to trinitrophenyl-modified autologous lymphocytes.

Effects of Con A-induced human mononuclear cells on the proliferative response of peripheral T cells were examined by using TNP-modified autologous lymphocytes as stimulator cells. Cells induced by incubation with Con A contained both suppressor cells and amplifier cells. The former were induced from nylon wool-nonadherent T cells and these precursor cells were sensitive to mitomycin treatment. On the other hand, amplifier precursor cells were nylon wool-nonadherent T cells and were resistant to mitomycin treatment. Cell proliferation was required for the induction of suppressor cells but not for the induction of amplifier cells. Con A-induced suppressor effector cells were both nylon wool-adherent and nonadherent cells, on the contrary, Con A-induced amplifier effector cells were nonadherent cells. A small number of macrophages enhanced the suppressive activity of nonadherent T cells when added at the induction phase of suppressor T cells.

Cell Adhesion↗