Biomedical subjects

Yutaka Fujiki

Publications and source records attributed to Yutaka Fujiki.

6 recordsLinked to original sources

PubMed2006

Third nerve palsy and serous retinal detachment with preeclampsia.

Visual disturbances occur more frequently during preeclampsia than during pregnancy in general, but visual disturbances due to cranial nerve palsy are rare. We present the case of a 35-year-old preeclamptic woman with left third nerve palsy and left serous retinal detachment. The patient complained of visual disturbance and double vision soon after cesarean section. Left third nerve palsy and left serous retinal detachment were diagnosed by urgent ophthalmologic evaluation. Aneurysm and organic brain lesion were ruled out by diagnostic imaging. By 2 months postpartum, the visual disturbance had improved spontaneously.

Adult↗

PubMed2005

Evaluating performance of a pixel array semiconductor SPECT system for small animal imaging.

OBJECTIVES: Small animal imaging has recently been focused on basic nuclear medicine. We have designed and built a small animal SPECT imaging system using a semiconductor camera and a newly designed collimator. We assess the performance of this system for small object imaging. METHODS: We employed an MGC 1500 (Acrorad Co.) camera including a CdTe semiconductor. The pixel size was 1.4 mm/pixel. We designed and produced a parallel-hole collimator with 20-mm hole length. Our SPECT system consisted of a semiconductor camera with the subject holder set on an electric rotating stage controlled by a computer. We compared this system with a conventional small animal SPECT system comprising a SPECT-2000H scanner with four Anger type cameras and pinhole collimators. The count rate linearity for estimation of the scatter was evaluated for a pie-chart phantom containing different concentrations of 99mTc. We measured the FWHM of the 99mTc SPECT line source along with scatter. The system volume sensitivity was examined using a flood source phantom which was 35 mm long with a 32-mm inside diameter. Additionally, an in vivo myocardial perfusion SPECT study was performed with a rat. RESULTS: With regards to energy resolution, the semiconductor camera (5.6%) was superior to the conventional Anger type camera (9.8%). In the count rate linearity evaluation, the regression lines of the SPECT values were y = 0.019x + 0.031 (r2 = 0.999) for our system and y = 0.018x + 0.060 (r2 = 0.997) for the conventional system. Thus, the scatter count using the semiconductor camera was less than that using the conventional camera. FWHMs of our system and the conventional system were 2.9 +/- 0.1 and 2.0 +/- 0.1 mm, respectively. Moreover, the system volume sensitivity of our system [0.51 kcps/(MBq/ ml)/cm] was superior to that of the conventional system [0.44 kcps/(MBq/ml)/cm]. Our system provided clear images of the rat myocardium, sufficient for practical use in small animal imaging. CONCLUSIONS: Our SPECT system, utilizing a semiconductor camera, permits high quantitative analysis by virtue of its low scatter radiation and high sensitivity. Therefore, this system may contribute to molecular imaging of small animals and basic medical research.

Animals↗

PubMed2003

Successful multilineage engraftment of human cord blood cells in pigs after in utero transplantation.

BACKGROUND: Successful engraftment of human hematopoietic stem and progenitor cells (HSPCs) in a large animal may serve not only as a model to study human hematopoiesis but also as a bioreactor to expand human HSPCs in vivo. The aim of this study was to accomplish xenotransplantation of human HSPCs into pig. METHODS: Total mononuclear or CD34-positive HSPCs obtained from human cord blood were xenotransplanted percutaneously under an ultrasonographic guidance into preimmune pig fetuses. Peripheral blood and bone marrow (BM) cells of recipient pigs were collected and analyzed for the presence of human cells by a polymerase chain reaction to detect human specific Alu sequence on DNA extracted from those cells. Fluorescence-activated cell sorting (FACS) analysis was also performed to detect human hematopoietic cells. RESULTS: Transplantation of human cord blood cells into pig fetuses aged less than 52 days postcoitus resulted in a good engraftment rate. In one case, engraftment was detected up to 315 days posttransplantation by polymerase chain reaction. Human hematopoietic cells were detectable also by FACS in peripheral blood and BM. Furthermore, human CD34+ HSPCs were also observed in the BM of recipients. Those CD34+ cells in BM were sorted by FACS and subjected to further analyses. First, in vitro colony formation assay resulted in formations of multilineage colonies. Second, when they were transplanted into an immunodeficient mouse they were engrafted in the mouse. CONCLUSIONS: These data indicate an engraftment of human HSPCs in pig BM. In utero transplantation of human HSPCs into a preimmune pig fetus is useful to establish a pig reproducing human hematopoiesis.

Animals↗

PubMed2002

Antepartum assessment of fetal cystic lymphangioma by magnetic resonance imaging.

Few reports of fetal cystic lymphangioma have described assessment in utero by magnetic resonance imaging (MRI). We evaluated a fetus with cystic lymphangioma by this method. Complementing the characteristic features of cystic lymphangioma in ultrasonographic images, prenatal MRI provided a detailed view of anatomic relationships of cysts to surrounding tissues in this case. This anatomic evaluation facilitated planning of perinatal management and choice of manner of delivery. We found MRI very helpful in antepartum assessment of fetal cystic lymphangioma.

Adult↗

PubMedDate not supplied

Second-trimester maternal pregnancy-associated plasma protein a and inhibin a levels in fetal trisomies.

OBJECTIVE: The aim of this study was to determine whether fetal trisomy is associated with altered levels of second-trimester maternal pregnancy-associated plasma protein A (PAPP-A) and inhibin A. METHODS: Maternal serum PAPP-A and inhibin A concentrations were measured at 15-17 weeks of gestation in 14 singleton pregnancies with fetal trisomy and in 56 matched pregnant controls. RESULTS: PAPP-A levels in the trisomy group were significantly lower than in controls. The inhibin A level with fetal trisomy 21 was slightly higher than the control group, but levels were not different between trisomies 18 and 13 and controls. CONCLUSION: Fetal trisomies 21, 18, and 13 are associated with a reduction in second-trimester maternal PAPP-A levels; trisomies 18 and 13 are not associated with increased inhibin A levels, unlike trisomy 21.

Adult↗

PubMedDate not supplied

Successful management of supraventricular tachycardia in a fetus using fetal magnetocardiography.

We report a fetus at 33 weeks of gestation with supraventricular tachycardia, which was successfully managed by transplacental administration of an antiarrhythmic agent. Fetal magnetocardiography (fMCG) revealed supraventricular tachycardia of the long RP' tachycardia type. Transplacental administration of sotalol, instead of digoxin, was selected as the first-line drug, and it successfully converted supraventricular tachycardia to sinus rhythm. The diagnosis of the type of supraventricular tachycardia was confirmed by electrocardiography after birth. Sotalol was also effective after birth to maintain sinus rhythm. This case demonstrates that fMCG is potentially useful for prenatal differentiation of the type of supraventricular tachycardia and for prenatal treatment of fetal tachyarrhythmias.

Adult↗