Biomedical subjects

Masami Nakajima

Publications and source records attributed to Masami Nakajima.

7 recordsLinked to original sources

PubMed2006

[Effect of photodynamic therapy with ATX-S 10 (Na) on experimental choroidal neovascularization].

PURPOSE: To evaluate an appropriate irradiative condition for selective occlusion of experimental choroidal neovascularization(CNV) with photodynamic therapy (PDT) using ATX-S 10 (Na). METHODS: Experimental CNV was induced in monkey eyes by laser photocoagulation. PDT(dose of irradiative energy 40 to 80J/cm2) was performed after 3.5 mg/kg of body weight intravenous injections of ATX-S 10(Na). CNV and retinal vessel occlusion induced by PDT was evaluated by fluorescein angiography (FA) at 1 and 7 days after irradiation. If FA showed no fluorescein dye leakage from CNV at 1 and 7 days after irradiation, CNV was evaluated by histopathological analysis at 7 days after irradiation. RESULTS: Within 30 to 33 minutes after ATX-S 10(Na) injection and irradiation with 50 to 60 J/ cm2, FA showed no fluorescein dye leakage from CNV and no closure of retinal vessels at 1 and 7 days after irradiation. Light micrographs showed occluded CNV, and retinal vessels remained patent and there was no apparent change in the inner layer of the retina. CONCLUSIONS: Irradiative condition of ATX-S10 (Na) 3.5 mg/kg was appropriate 30 to 33 minutes after ATX-S 10(Na) injection and irradiation with 50 to 60 J/cm2.

Animals↗

PubMed2003

[Surgical removal of choroidal neovascularization in angioid streaks].

PURPOSE: All the studies so far on surgical removal of choroidal neovascularization (CNV) in angioid streaks(AS) were conducted on a small number of cases. Therefore, a definitive evaluation of the surgical method was not available. The present study aimed to evaluate this surgical modality. SUBJECTS AND METHOD: We performed surgical removal of foveal CNV accompanied by AS. Eighteen eyes of seventeen patients were available for follow-up of over 12 months. Surgical indications included foveal CNV, fluorescence leakage from the CNV in late-phase fluorescein angiography, and visual acuity of 0.3 or lower. RESULTS: The best visual acuity was improved in 44% and unchanged in 44%. The final visual acuity was improved in 33% and unchanged in 39%. 22% had a preoperative visual acuity of 0.2 or above; and 44% and 17% achieved best and final visual acuity, respectively, of 0.2 or above. Since all cases developed atrophy of the choriocapillaris in the fovea, none of the cases were capable of fixation within atrophy. The fixation point was localized outside atrophy in 56% and fixation was poor in 44%. The diameter of postoperative atrophy of choriocapillaris was significantly greater (p < 0.05) than the preoperative CNV diameter. CNV recurred in 8 eyes(44%), 88% of which occurred within one year. CONCLUSION: Surgical removal of CNV in AS is an effective method to maintain preoperative visual acuity.

Aged↗

PubMed2002

A case of extramedullary plasmacytoma of the larynx.

An 84-year-old male with a complaint of hoarseness was examined. A mass lesion was recognized in the false vocal fold. The tumor was excised and found to consist of atypical plasmacytes. Immunopathological examination revealed that leukocyte common antigen (CD45), UCHLI (CD45RO), CD3 and L26 (CD20) were negative and that CD79 and Vs38C were positive. Neither uric Bence-Jones protein nor serum M-protein were observed. No other bony abnormalities were recognized on X-ray examinations including both bone and Ga scintigraphy. No atypical plasmacyte infiltration was observed in bone marrow. Our final diagnosis was extramedullary plasmacytoma of the larynx. Radiotherapy was performed following surgery. The tumor did not progress to multiple myeloma and no recurrence has been observed after 2 years.

Aged↗

PubMed2002

Glottal configuration, acoustic, and aerodynamic changes induced by variation in suture direction in arytenoid adduction procedures.

Arytenoid adduction is a phonosurgical procedure in which the arytenoid cartilages are approximated to reduce posterior glottal gap size and improve voice. Voice outcomes following arytenoid adduction are not always optimal. The goal of this study was to systematically vary suture direction and force of pull on the arytenoid cartilages in a human excised laryngeal model to determine the optimal combination of factors for reducing glottal gap and improving voice. Several factors demonstrated significant effects. Changes in suture direction and force of pull affected glottal configuration in both the horizontal and vertical planes. Increased force of pull on the muscular process resulted in increased adduction of the vocal process for all suture directions. Changes in suture direction and force of pull also affected acoustic and aerodynamic measures of induced voice. Therefore, voice outcomes can be optimized with arytenoid adduction if the vocal fold plane is accurately adjusted.

Acoustics↗

PubMedDate not supplied

Correlation between indocyanine green angiographic findings and histopathology of polypoidal choroidal vasculopathy.

PURPOSE: To analyze the histopathology of polypoidal choroidal vasculopathy (PCV) and choroidal neovascularization (CNV) developing from PCV, the authors evaluated correlations between pathological findings and the findings of preoperative indocyanine green angiography (IA). METHODS: Two specimens were obtained during CNV excision associated with PCV. PCV tissue was excised with the CNV. The specimens were examined by light microscopy. RESULTS: In one case, IA revealed polypoidal lesions exhibiting hyperfluorescence in both the early and the late phase, and in the affected area, abnormally dilated vessels were identified histologically underneath relatively healthy retinal pigment epithelium (RPE). In the other case, the polypoidal lesions seen on IA showed early hyperfluorescence and late isofluorescence, and dilated vessels were observed under the RPE; perivascular amorphous material was present. The RPE adhered to the side of the choroid, and there was CNV under the neurosensory retina in both cases. The CNV had numerous vascular lumens, was not surrounded by the RPE, and exhibited few fibrous components. CONCLUSIONS: IA findings vary depending on the condition of the RPE located above the PCV and the extent of amorphous material around the PCV.

Aged↗

PubMedDate not supplied

Correlation between angiographic and pathological findings in experimental choroidal neovascular membranes after transpupillary thermotherapy.

PURPOSE: To evaluate the correlation between angiographic and pathological findings in experimental choroidal neovascular membranes after transpupillary thermotherapy (TTT). METHODS: Experimental subretinal choroidal neovascular membranes were produced in the monkey eye macula by intense photocoagulation. TTT was delivered, targeting the choroidal neovascular membranes, using a diode laser at 810 nm. One week and 4 weeks after TTT, indocyanine green angiography (IA), fluorescein angiography (FA), optical coherence tomography (OCT), and histological examinations were performed. RESULTS: One week after TTT, indocyanine green dye leakage from choroidal neovascular membranes was reduced on IA, and FA showed staining in the late phase. Light microscopic examination showed numerous small-caliber blood vessels and persistent subretinal exudation. Four weeks after TTT, there was no indocyanine green dye leakage on IA, and FA showed staining. OCT showed a decrease in retinal detachment. Light microscopic examination showed fewer blood vessels and subretinal exudation had disappeared. Choroidal neovascular membranes were composed of fibrous tissue. CONCLUSIONS: Changes in angiographic and OCT findings observed after TTT were inferred to be the result of accelerated fibrosis due to TTT and the disappearance of exudation.

Animals↗

PubMedDate not supplied

Twenty-gauge Transconjunctival Vitrectomy.

PURPOSE: To describe a new 20-gauge transconjunctival vitrectomy procedure that we designed, to evaluate its usefulness, and to compare two different methods of use. METHODS: The records of 431 patients (433 eyes) who underwent 20-gauge transconjunctival vitrectomy at the Surugadai Hospital of Nihon University between March 2003 and January 2004 were studied retrospectively. In surgical method 1, 20-gauge wounds were made through the conjunctiva and sclera together. In surgical method 2, 20-gauge conjunctival openings were made 2 mm posterior to the sclerotomies. Absorbable sutures were used to stitch the scleral and conjunctival openings simultaneously in both methods. RESULTS: A 20-gauge transconjunctival vitrectomy has various benefits and is indicated for nearly all ocular diseases. Moreover, it is not limited by the intraocular instruments required. However, since cannulas were not placed in all ports, conjunctival edema occurred more easily with surgical method 2 owing to the leakage of perfusion fluid. CONCLUSIONS: This new 20-gauge transconjunctival vitrectomy procedure has various benefits and is indicated for nearly all ocular diseases. It is not limited by the intraocular instruments required.

Adult↗