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Biomedical subjects

N Masaoka

Publications and source records attributed to N Masaoka.

31 records · Page 2Linked to original sources
PubMed1986

Clinical application of the perineal scan: prepartum screening for cord presentation.

Real-time linear-array ultrasonographic scanning was performed from the perineum on 12 primiparous term women with the fetus in breech or foot presentation. Scanning was done with the patient initially in lithotomy position and then in semi-Trendelenburg position if a better view was required. The technique appears to be excellent for visualization of the forelaying umbilical cord even when the cervix is closed and is not affected by the acoustic shadow of the public arch. The information obtained by the scanning may be of value in avoiding or improving perinatal mobility of breech/footling fetuses and in providing better perinatal management.

Breech Presentation↗
PubMed1983

Light and electron microscopic studies of malignant melanoma of conjunctiva and palpebra.

The authors experienced one case of malignant melanoma of the superior palpebral conjunctiva and the inferior palpebral skin, originating from benign acquired melanosis of the bulbar conjunctiva which developed in a 48-year-old man. Orbital exenteration including superior and inferior palpebrae was performed, and the removed tissue was examined by light and electron microscopy. In the temporal bulbar conjunctiva, melanocytes containing abundant fine melanin granules proliferated over almost the whole area of the epithelial layer. Cellular atypia and karyomitosis were not observed. The basement membrane remained intact with no proliferation of melanocytes in the substantia propria. However, in the perivascular area, in addition to the moderately prominent infiltration by lymphocytes and plasma cells, infiltration by melanophages was observed relatively frequently. Based on these findings, it was confirmed that the primary lesion of the bulbar conjunctiva was an acquired melanosis of Stage IB as classified by Zimmerman. The black nodular tumors of the superior palpebral conjunctiva and inferior palpebral skin consisted of melanoma cells showing markedly prominent cellular and nuclear atypia. The nuclei showed indentations in the membrane with electron-lucent karyoplasm, each having one nucleolus. The cytoplasm contained many round or elongated melanosomes in various developmental stages, with sizes of about 0.7 micron. Scattered among melanoma cells were a number of melanophages which had phagocytized many melanosomes at various stages of maturity.(ABSTRACT TRUNCATED AT 250 WORDS)

Conjunctival Neoplasms↗
PubMedDate not supplied

Comparison between histopathologic findings and indocyanine green angiographic findings in Lewis rats with experimental autoimmune uveoretinitis.

PURPOSE: Recently, indocyanine green angiography (IA) was used to examine chorioretinal circulation in posterior uveitis in humans, and abnormal IA findings were reported. However, choroidal pathologic examination in conjunction with these abnormal IA findings has rarely been done. Experimental autoimmune uveoretinitis (EAU) is a model for posterior uveitis in humans. The purpose of this study was to correlate abnormal IA findings in Lewis rats with EAU with pathologic findings. METHODS: Eleven male Lewis rats were immunized with bovine S-antigen in complete Freund's adjuvant with Bordetella pertussis. After immunization, IA was performed by using a scanning laser ophthalmoscope. Eyes with abnormal IA findings were enucleated and examined histopathologically. RESULTS: Demonstrated leakage from retinal vessels at the initial stage of disease; a decrease of background fluorescence and of the number of moderate and large vessels of the choroid, and leakage from choroidal vessels at the progressive stage; and hypofluorescent areas at the late stage. Histopathologic examination at the initial, progressive, and late stages revealed inflammation of the inner layers of the retina, a large number of inflammatory cells in the thickened retina and choroid, and impaired choroidal capillaries, respectively. CONCLUSION: Since a correlation between pathologic findings and IA findings was demonstrated in Lewis rats with EAU, IA may be useful for evaluating the severity of uveitis in humans.

Animals↗
PubMedDate not supplied

Indocyanine green angiographic findings in 3 patients with traumatic hypotony maculopathy.

PURPOSE: Little is known about the choroidal circulation in human eyes with ocular hypotony. Recently, indocyanine green angiography (IA) became a useful method for examining choroidal circulation. The present study using IA was designed to determine choroidal circulatory disturbances in patients with traumatic hypotony maculopathy. METHODS: Indocyanine green angiography was performed on 3 consecutive patients (3 eyes) with traumatic hypotony. One patient underwent IA using an infrared fundus camera only during the hypotony stage. The other 2 patients underwent IA using a scanning laser ophthalmoscope before and after recovery of intraocular pressure (IOP). RESULTS: During the hypotony stage, IA revealed multiple hypofluorescent spots in many parts of the fundus, sector hypofluorescent areas, dilatation, and tortuosity of the choroidal vessels in the posterior pole. These findings had not been detected by fluorescein angiography. After surgical treatment, IOP returned to the normal range and visual acuity improved. Indocyanine green angiography showed improvement of the sector hypofluorescent areas, and dilatation and tortuosity of choroidal vessels in the posterior pole. However, most of the hypofluorescent spots and regional delay of choroidal filling remained. CONCLUSIONS: Indocyanine green angiography revealed that choroidal circulatory disturbances occurred during the hypotony stage and that some remained during the recovery stage.

Adult↗