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Biomedical subjects

Y Hatsukawa

Publications and source records attributed to Y Hatsukawa.

At least 19 recordsLinked to original sources
PubMed2006

Analysis of cadmium in food by multiple prompt gamma-ray spectroscopy.

The Cd concentration in food is a public concern related to the human health. In order to remove Cd-polluted food, the development and validation of a rapid and sensitive method of Cd analysis is required. By applying the multiple gamma-ray detection method to prompt gamma-ray analysis (PGA), the influence from nuclei which emit only one prompt gamma-ray at a time at every neutron capture reaction can be reduced, therefore the quantification limit of Cd is improved significantly. The limit of Cd contained in rice in the case of MPGA was evaluated, and under our proposed experimental conditions, it may be possible to quantify Cd content in rice to within 0.2 ppm in 10 min.

Cadmium↗
PubMed2002

Isotopic ratio of 129I/127I in seaweed measured by neutron activation analysis with gamma-gamma coincidence.

129I is a long-lived (1.6 x 10(7) y) radionuclide that is produced in nature as the result of spontaneous fission of heavy elements and reaction of xenon with cosmic rays. Recently, however, artificial sources from nuclear power plants and nuclear test explosions have become a significant component of environmental radioactive iodine. Coincidence gamma-ray detection using Ge detectors makes it possible to simultaneously resolve the numerous gamma-rays produced by neutron activation. In this study, the coincidence gamma-ray detection technique was combined with neutron activation analysis to determine the radioactive iodine composition of seaweed. The ratio of 129I/127I in this common Japanese food item collected from the Ibaraki prefecture has been derived without the need for radiochemical purification. The isotopic ratio of 129I/127I in Kajime algae is 3.5(5) x 10(-10).

Gamma Rays↗
PubMed1998

Cohen syndrome with high urinary excretion of hyaluronic acid.

Cohen syndrome (MIM 216550) is an autosomal recessive disorder of unknown pathogenesis. The clinical manifestations of Cohen syndrome can be explained as a connective tissue disorder. We found a remarkably high level of urinary hyaluronic acid in 3 patients with Cohen syndrome. Hyperhyaluronic aciduria is a characteristic finding in Werner syndrome and some other conditions. We suggest that the basic defect of Cohen syndrome is associated with a metabolic abnormality in the extracellular matrix.

Abnormalities, Multiple↗
PubMed1997

Premature aging syndrome with osteosarcoma, cataracts, diabetes mellitus, osteoporosis, erythroid macrocytosis, severe growth and developmental deficiency.

We describe a premature aging disorder in a 15-year-old girl with severe growth and developmental deficiency. Her clinical findings included osteosarcoma, nuclear and subcapsular cataracts, insulin-resistant diabetes mellitus, osteoporosis, epilepsy, foot ulcers, erythroid macrocytosis, and unusual facial appearance. Hyaluronic acid levels in serum and urine were normal. Cultured skin fibroblasts had a normal potential for in vitro growth. This finding represents a new and unique premature aging syndrome.

Abnormalities, Multiple↗
PubMed1997

Ophthalmic findings in a case of hemophagocytic syndrome.

PURPOSE: To report a case of hemophagocytic syndrome, which is characterized by hemophagocytosis of histiocytes; optic nerve involvement, and unusual retinal white patches. METHOD: Case report. A 10-year-old boy had repeated relapses of hemophagocytic syndrome. He complained of swelling of the right upper eyelid and bilateral visual disturbance. RESULTS: Ophthalmoscopic examination disclosed bilateral optic disk edema, retinal hemorrhages, and multiple perivenous white patches in the retina. Magnetic resonance imaging demonstrated enlargement of both optic nerves. After chemotherapy and bone marrow transplantation, his visual acuity improved in both eyes, and retinal patches changed to inactive-appearing scars. CONCLUSION: Hemophagocytic syndrome may manifest with ophthalmic findings such as optic nerve involvement, retinal hemorrhages, and multiple white perivenous retinal patches.

Child↗
PubMed1997

Rhabdomyoma of the orbit in a child.

PURPOSE: To study a case of rhabdomyoma of the orbit in a 16-month-old boy. METHOD: The child had progressive right proptosis for 1 month. He underwent a computed tomographic scan, which showed an irregular right retrobulbar mass and partial resection. RESULTS: Histologic examination disclosed well-differentiated striated muscle cells with a mixture of collagen fibers and immature striated muscle cells with centrally placed nuclei. The specimen lacked nuclear atypia, indicating benign rhabdomyoma of the orbit. During the 1 1/2-year follow-up, the patient did not receive additional treatment, and no regrowth occurred. CONCLUSION: Rhabdomyoma can occur in the orbit of a child. Because of differences in treatment, rhabdomyoma must be distinguished from rhabdomyosarcoma.

Humans↗
PubMed1996

Macular coloboma-like lesions and pigment abnormalities as complications of cryotherapy for retinopathy of prematurity in very low birth-weight infants.

PURPOSE: Cryotherapy for retinopathy of prematurity (ROP) is effective in reducing the incidence of blindness in premature infants. However, macular complications associated with successful treatment have not yet been well studied. METHODS: Eighteen very low birth-weight (< 1,251 g) infants (32 eyes) who received cryotherapy for ROP were examined serially for regression of disease and for development of macular abnormalities. Patient characteristics and treatment factors were evaluated to identify risk factors associated with the development of macular abnormalities after successful cryotherapy. RESULTS: Eleven of 32 eyes (34.4%) that had undergone cryotherapy developed significant macular abnormalities, including macular coloboma-like change (six eyes), macular hyperpigmentation (two eyes), irregularly mottled macular hyperpigmentation and hypopigmentation (two eyes), and macular hyperpigmentation and hypopigmentation with subretinal proliferation (one eye). Corrected visual acuity in affected eyes ranged from 0.15 to 0.03 (20/133 to 20/666) compared with 1.0 to 0.2 (20/20 to 20/100) in treated eyes without macular abnormality (P = .0002). No difference in gestational age was noted between infants who did or did not develop macular coloboma-like lesions or pigment abnormalities. Eyes with macular abnormality had more posterior disease (P = .037) and received significantly more cryotherapy than did eyes without macular abnormality (P = .0005). CONCLUSIONS: In very low birth-weight infants receiving cryotherapy for ROP, development of macular coloboma-like lesions and macular pigment abnormalities were related to greater severity of ROP and a greater amount of cryotherapy. Macular abnormalities were associated with markedly worse visual outcomes than were treated eyes without macular abnormality.

Birth Weight↗
PubMed1994

Mathematical analysis and experiment on the corneal reflex test in spectacle wearers.

An experimental study and mathematical analysis of the corneal reflex test was undertaken in spectacle wearers. In the experimental study, photographs were taken of the corneal reflex through spectacles and the conversion ratios determined as measured in degrees/mm. In the mathematical analysis, the magnification effect of the lens was elucidated by three methods: geometrical analysis; real measurement of magnification factor; and ray tracing analysis. The real measurement of the conversion ratios was in good agreement with the conversion ratios determined by the three mathematical analyses. These results clearly showed that the corneal reflex test can be clinically useful even in wearers of spectacles.

Blinking↗
PubMed1993

The progression of retinopathy of prematurity and fluctuation in blood gas tension.

In this study, the relationship between the fluctuation in blood oxygen and carbon dioxide tension and the progression of acute retinopathy of prematurity (ROP) was evaluated. Eighteen extremely premature infants were selected on the basis of the following criteria: gestational age less than 26 weeks, oxygen supply or mechanical ventilation for more than 50 days, transcutaneous oxygen pressure (TcPO2) recorded almost once per hour, and arterial oxygen pressure (PaO2) and arterial carbon dioxide pressure (PaCO2) measured intermittently, for over 8 weeks after birth. All of these infants developed ROP, which ceased progressing in 7 infants (group I, stage 1 or 2 ROP, international classification), but advanced in 11 (group II, stage 3 or 3+). The fluctuations in TcPO2, PaO2, and PaCO2 are represented as coefficients of both variation (CV) and mean difference (D) in these two groups. The results demonstrate that both the CV and D values of TcPO2 are significantly elevated in group II infants compared with group I infants, in the first and second 3-weeks periods, and over the entire 9-week period after birth. The incidences of extreme hyperoxemia (TcPO2 > or = 100 mm Hg) and hypoxemia (TcPO2 < 30 mm Hg) in recorded TcPO2 time series show no significant differences between these two groups. We conclude that extremely premature infants with widely fluctuating arterial oxygen tension may have a greater chance of developing progressive ROP.

Blood Gas Monitoring, Transcutaneous↗
PubMed1992

[Short-term and long-term prognosis of recession-resection surgery for exotropia].

The short- and long-term results of recession-resection surgery on 141 exotropic patients were analyzed. The corrected angle of exodeviation one week after surgery was not affected by age at surgery, state of binocular vision or the type of intermittent exotropia. The corrected exodeviation was larger when the pre-operative exodeviation exceeded 30 prism diopters or when previous surgery had been performed. Since there was no difference between the angle of deviation at 4 and 8 years postoperatively, the period of four years was considered to be appropriate for long-term assessment. Post-operative exophoria of less than 15 prism diopters were obtained in patients whose short-term results were overcorrected or were under 5 prism diopters of exodeviation. The surgical guideline for exotropia should be determined considering the short-term and the long-term prognosis. It was concluded that the optimal time for surgery was between 5 and 10 years of age.

Adolescent↗
PubMedDate not supplied

Treatment of A-pattern esotropia with marked mongoloid slanting palpebral fissures.

BACKGROUND: The association of oblique palpebral fissures and A- or V-pattern has not been clarified. We report two cases of A-pattern esotropia with marked mongoloid slanting palpebral fissures associated with vertical displacement of the horizontal rectus muscle. CASES: Case 1 was a boy with Prader-Willi syndrome. He showed A-pattern esotropia with upward slanting palpebral fissures. Severe superior oblique muscle overaction was observed. Case 2 was a girl with meningocele. She also showed A-pattern esotropia with upward slanting palpebral fissures. OBSERVATIONS: In case 1, weakening surgery of the superior oblique muscles did not improve the A-pattern. Coronal images of computed tomography showed one-half-muscle-width upward displacement of both lateral rectus muscles. After downward transposition surgery of the lateral rectus muscles, the preoperative A-pattern of 25 prism diopters (PD) was successfully corrected to 10 PD. In case 2 also, upward displacement of both lateral rectus muscles was shown by computed tomography. The preoperative A-pattern of 26 PD was corrected to 4 PD postoperatively after upward transposition surgery of the medial rectus muscles. CONCLUSIONS: The vertical displacement of horizontal rectus muscles was considered the principal cause of A-pattern in these cases associated with marked mongoloid slanting palpebral fissures.

Child, Preschool↗