Biomedical subjects

Y Hayabuchi

Publications and source records attributed to Y Hayabuchi.

41 records · Page 3Linked to original sources

PubMedDate not supplied

Age-related criteria for signal-averaged electrocardiographic late potentials in children.

This study examined the age-related criteria of signal-averaged electrocardiographic (SA-ECG) parameters in children. SA-ECGs were obtained in 82 healthy volunteers in six groups depending on age (group 1: 1 day to < 1 month; group 2: 1 month to < 1 year; group 3: 1 to < 6 years; group 4: 6 to < 12 years; group 5: 12 to < 20 years; group 6: 20 to < 40 years). To examine the effect of heart rate on the parameters of SA-ECG, right atrial pacings were performed in 4 children with a ventricular septal defect aged 1-7 years. The root mean square voltage (RMS) was high; and the filtered QRS (f-QRS) duration and the duration of the low amplitude signal (LAS) were low during childhood, especially in infants (group 2), compared with those in adults. Late duration (LD) had no significant difference among age groups. The criteria for ventricular late potential were as follows: RMS < 25 microV, LAS > 35 ms, f-QRS duration > 110 ms, and LD > 35 ms for those age 1 day to < 1 month; RMS < 40 microV, LAS > 30 ms, f-QRS duration > 100 ms, and LD > 35 ms for those age 1 month to < 1 year; RMS < 20 microV, LAS > 40 ms, f-QRS duration > 130 ms, and LD > 35 ms for those age 1 to < 20 years; and RMS < 15 microV, LAS > 45 ms, f-QRS duration > 135 ms, and LD > 35 ms for those age 20 to < 40 years. RMS and LAS correlated with f-QRS duration (r = -0.78 and 0.76, respectively; p < 0.05), suggesting that these parameters are associated with the thickness of the ventricular muscle and the ventricular conduction time. Right atrial pacing had no effect on the measured SA-ECG parameters. The age-related differences in SA-ECG parameters might be due to age-related differences in the thickness of the ventricular muscle and the ventricular conduction time but are not due to differences in the heart rate. The age difference of each parameter on SA-ECG should be considered for ventricular late potentials.

Adolescent↗

PubMedDate not supplied

Primary mitral valve sarcoma in infancy.

Primary cardiac sarcoma is a rare tumor, found especially in children, particularly in the left side of the heart. This report describes a rare case of primary mitral valve sarcoma in a 7-month-old male infant with hemiparesis and heart murmur who underwent mitral valve replacement because of excessive invasion of the mitral valve by the tumor. The patient remains well, free of recurrence and cerebral metastasis, and without adjuvant therapy 18 months after the operation.

Angiography↗

PubMedDate not supplied

Plasma concentrations of atrial and brain natriuretic peptides and cyclic guanosine monophosphate in response to dobutamine infusion in patients with surgically repaired tetralogy of fallot.

We examined the plasma concentrations of atrial and brain natriuretic peptides (ANP and BNP) and cyclic guanosine monophosphate (cGMP) during dobutamine infusion and their relationship with hemodynamic parameters in 14 patients with surgically repaired tetralogy of Fallot (TOF). Dobutamine was infused at an initial dose of 5 microgram/kg/min and increased by 5 microgram/kg/min up to 20 microgram/kg/min. The plasma ANP, BNP, and cGMP concentrations were determined before infusion, at the end of each stage, and 15 minutes after discontinuing dobutamine infusion. The plasma concentrations of ANP, BNP, and cGMP were elevated in all patients before dobutamine infusion. The ANP, BNP, and cGMP concentrations decreased in 11 of the 14 patients during dobutamine infusion. In contrast, the plasma ANP and BNP concentrations increased in the remaining 3 patients without a change in the cGMP concentration. The right ventricular pressure and volume were significantly elevated in these patients. The plasma cGMP concentration correlated with the ANP concentration (r = 0.62, p < 0.01) but not the BNP concentration. The plasma ANP concentration during dobutamine infusion correlated with right ventricular systolic pressure (r = 0.71, p < 0.05), mean right atrial pressure (r = 0.29, p < 0.05), and mean pulmonary capillary wedge pressure (r = 0.32, p < 0.05). The BNP concentration correlated with right ventricular volume (r = 0.61, p < 0.05) and systolic pressure (r = 0. 46, p < 0.05). In conclusion, rapid changes in ANP, BNP, and cGMP concentrations during dobutamine infusion reflect the changes in atrial and ventricle pressure and volume overload. In surgically repaired TOF, the ANP concentration is affected by right ventricular systolic pressure, right atrial pressure, and pulmonary capillary pressure. Furthermore, the BNP concentration reflects right ventricular pressure and volume overload.

Adrenergic beta-Agonists↗

PubMedDate not supplied

A new sensitive and specific combination of CD81/CD56/CD45 monoclonal antibodies for detecting circulating neuroblastoma cells in peripheral blood using flow cytometry.

PURPOSE: Intensive chemoradiotherapy followed by peripheral blood stem cell transplantation has been introduced to treat children with advanced neuroblastoma (NBL). Detection of NBL cells in peripheral blood (PB) is important to prevent reinfusion of NBL cells. Several immunologic methods have been proposed for detecting NBL cells in hematologic samples. The development of a sensitive and specific combination of monoclonal antibodies (MoAbs) for detecting small numbers of NBL cells in PB using flow cytometry remains an important challenge. METHODS: Twenty-one clinical samples from NBL tissues or smears containing NBL cells were examined for reactivity against CD81, CD56, and CD9 using an immunocytochemical technique. The expressions of CD81, CD56, CD9, and antihuman disialoganglioside GD2 MoAb (GD2) in five NBL cell lines were assayed by flow cytometry. For the evaluation of sensitivity, five NBL cell lines were added to normal PB and the detection level of the combination of CD81/CD56/CD45 MoAbs was compared with that of CD9/CD56/CD45 MoAbs (reported previously). One hundred thirty-three normal PB samples were examined to determine the sensitivity and specificity of this method. RESULTS: All NBL cell lines showed strong positivity with CD81 and CD56 MoAb. However, CD9 MoAb was weakly positive against the five NBL cell lines. GD2 MoAb reacted strongly with four NBL cell lines, although almost the entire cell population of the SK-N-SH NBL line failed to bind the GD2 MoAb. In vitro experiments using NBL cell lines demonstrated that tumor cells added to normal PB cells could be detected by flow cytometry using CD81/CD56/CD45 MoAbs even at a concentration of 0.005%. Through comparative studies, the combination of CD81/CD56/CD45 MoAbs was found to be more sensitive and specific than that of CD9/CD56/CD45 MoAbs for detecting small numbers of NBL cells using the above cell lines. CONCLUSIONS: Triple-color flow cytometric analysis using CD81/CD56/CD45 MoAbs is useful for detecting NBL cells in PB. Further studies testing this approach using samples of PB with NBL contamination are needed to test this approach in patients.

Adolescent↗

PubMedDate not supplied

Cytologic features of desmoplastic infantile ganglioglioma: a report of two cases.

BACKGROUND: Desmoplastic infantile ganglioglioma (DIG) is a rare intracranial tumor of infancy, characterized by solid and cystic components, voluminous size and supratentorial location. Although its histologic features have been reported, there has been no cytologic description of the tumor. Cytologic findings on imprint and aspirated material from two cases of histologically verified DIG are discussed. CASES: A 12-month-old male with cutis marmorata telangiectatica congenita and a 44-month-old female with episodes of spasm were referred to our center. Radiologic examination revealed a large, cystic, supratentorial mass in both patients. The mass was surgically removed, and histology revealed prominent desmoplasia with a mixture of astroglial and neuronal cells. Cytologic findings on imprint material and the needle aspirates taken from the cystic area of the tumor revealed a few isolated or sheetlike arrangements of small cells positive for glial fibrillary acidic protein and a few large cells with abundant cytoplasm and prominent nucleoli, positive for neuronal marker. CONCLUSION: Although distinction between ganglioglioma and DIG may be difficult by cytology alone, with the characteristic clinical presentation and radiologic findings, the possibility of DIG should be kept in mind when the specimens contain both astroglial and neuronal elements.

Biopsy, Needle↗