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Biomedical subjects

H Hamada

Publications and source records attributed to H Hamada.

At least 577 records · Page 32Linked to original sources
PubMedDate not supplied

Prenatal sonographic diagnosis of Beckwith-Wiedemann syndrome in association with a single umbilical artery.

Beckwith-Wiedemann syndrome is an inherited disorder most commonly characterized by prenatal or postnatal overgrowth, macroglossia, omphalocele, unusual earlobe creases, and increased risk of neoplasia. Several reported cases of this syndrome have been prenatally diagnosed, but no report has described the occurrence of this syndrome in association with a single umbilical artery. We report a case in which prenatal sonographic examination demonstrated fetal overgrowth, macroglossia, and omphalocele together with a single umbilical artery; our prenatal diagnosis of Beckwith-Wiedemann syndrome was confirmed after birth of the infant. The possibility of this syndrome should be considered when performing a detailed sonographic examination of a fetus with a single umbilical artery.

Adult↗
PubMedDate not supplied

Validation of the proximal isovelocity surface area method for assessing mitral regurgitation in children.

The proximal isovelocity surface area (PISA) method for calculating volume flow through the regurgitant orifice has attracted significant attention. A number of in vitro studies and clinical studies in adults suggest that the method is accurate. However, when applying the method to children it must be noted that the absolute regurgitation volume is small, and the range of body sizes is wide. This study investigated the accuracy of the PISA method for quantitative assessment of the severity of mitral regurgitation in children. Twenty children aged 7 months to 12 years (average 4.7 years) with mitral regurgitation but without interventricular shunt or aortic stenosis were selected for this study. Underlying cardiac diseases included atrioventricular septal defects in nine, isolated mitral regurgitation in five, and association with other heart defects in six. The PISA radius (r) and the duration of regurgitation (T) were measured on color M-mode recordings, with the M line passing through the center of the PISA. Assuming that the PISA is a hemisphere, maximal regurgitant flow rate (MFR: ml/s) was calculated as MFR = 2pi x r2 x V (r = maximal radius, V = aliasing velocity), and regurgitant stroke volume (RSVpisa) as RSVpisa = 2pi x MSR x V x T (MSR = mean square of the PISA radius during regurgitation). As a validating standard, total stroke volume (TSV) using two-dimensional echocardiography determined by the area-length volumetry method and forward stroke volume (FSV) by the pulsed Doppler method were measured, and regurgitant stroke volume (RSVD: RSVD = TSV - FSV) and regurgitant fraction (RF: RF = RSVD/TSV) were calculated. A linear correlation was found between MFR, RSVpisa, and RSVD (X) (MFR = 4.2X + 54.0, r = 0.84. RSVpisa = 1. 0X + 9.8, r = 0.90), and both RSVpisa and MFR divided by body surface area (BSA: m2) revealed a significant correlation with regurgitant fraction (X) by nonlinear regression analysis (RSVpisa/BSA = 26.2 x X/(1 - X) + 16.8, r = 0.85. MFR/BSA = 121.8 x X/(1 - X) + 92.2, r = 0.79). It is concluded that maximal regurgitant flow rate, regurgitant stroke volume, and regurgitant fraction can be accurately predicted in children using the PISA method by Doppler echocardiography.

Child↗
PubMedDate not supplied

ATP-dependent protease in human placenta.

We have found that human placental mitochondria contain ATP-dependent protease in a soluble form. The molecular weight of the protease have been up to 108,000, which is the same as ATP-dependent protease in bovine adrenal cortex. Since this protease has been distributed among steroid hormone-producing tissues such as testis and adrenal cortex and ATP-dependent protease can degrade cytochrome P-450scc, a key enzyme in steroid hormone biosynthesis, we suggest that the protease may have an important role in the regulation of steroid hormone metabolism.

ATP-Dependent Proteases↗