Biomedical subjects
Publications and source records attributed to M Tamai.
A new antibiotic armillaric acid (2), has been isolated from the cultured mycelia of Armillaria mella (Vahl. ex Fr.) Quel (Trichlometaceae). Its structure was elucidated on the basis of the spectral data. Compound 2 exhibits inhibitory activity against gram-positive bacteria and yeast.
The authors describe a family in which one member had pattern dystrophy of the retinal pigment epithelium. The proband also had neovascular membranes which resulted in decreased visual acuity. Two other family members had abnormal electro-oculographic findings, but a clinical normal-appearing fundus that could represent an early stage of the disease. The incidence of this condition in this family indicates autosomal dominance as the inheritance pattern of this dystrophy.
We studied the possible influence of oral metyrapone tartrate (which inhibits the adrenal biosynthesis of cortisol) on the rate of aqueous humor flow in 9 eyes of 8 normal subjects by fluorophotometry. On the control day, the mean value of Ko was 1.04 +/- 0.32 min-1 x 10(-2), where Ko was the loss coefficient from the anterior chamber. On the metyrapone trial day, the mean value of Ko was 0.63 +/- 0.15 min-1 x 10(-2). The mean difference in Ko between the two periods was significant (P less than 0.005). These results indicated that systemic metyrapone administration decreases the rate of aqueous humor flow.
Successive purification of the extract from Canarium album and Euphorbia nematocypha, guided by antihepatotoxic activity in primary cultured rat hepatocytes, led to the isolation of brevifolin (1), hyperin (2), ellagic acid (3) and 3,3'-di-O-methylellagic acid (4) as hepatoprotective compounds. Compounds 1,3 and 4 also reduced carbon tetrachloride (CCl4)-induced liver damage in mice. The hepatoprotective activities of 1, 2, 3 and 4 in vitro and in vivo are apparently due to their antioxidative effects, which were exhibited by further studies using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and CCl4-induced lipid peroxidation systems.
1. The urinary and plasma metabolites of 14C-loxistatin, a new thiol protease inhibitor, were studied after oral administration to rats. 2. The major metabolites in urine were identified as loxistatin acid (M-1), a pharmacologically active form, and its hydroxy metabolites (M-4a and M-4b). These metabolites were also shown to be the major metabolites in plasma. 3. The inhibitory activity of the synthetic metabolite, M-4b, on papain was almost the same as that of loxistatin acid.
We examined a 2-year-old child with optic nerve evulsion after facial contusion. The optic nerve head could not be seen because of overlying preretinal and vitreous hemorrhage. Fluorescein angiography demonstrated no infusion of dye into the central retinal artery in the right eye. The electroretinogram was subnormal, and visual evoked potential revealed poor response with right eye stimulation. Ten days later, the fundus could not be seen due to vitreous opacity, so pars plana vitrectomy was performed 62 days after injury and optic nerve evulsion was recognized. This case revealed the possibility of traumatic optic nerve evulsion, even if only very slight skin injury were found around the orbital and ocular regions.
Diurnal variations of serum immunosuppressive acidic protein (IAP) were studied in four healthy individuals and in four patients with complete type Behçet's disease with active uveitis. The circadian rhythm of the serum level of the protein was recognized in both groups. The peak value was at 1800 hours in the healthy subjects and at 2200 hours in those with Behçet's disease. Although the exact mechanism underlying the rhythmic variation in this clinical marker of acute phase reaction is unknown, the close interaction between the immune system and the rhythmicity of corticosteroids should be considered. The data also suggest that the time of day when sampling is carried out should be considered when evaluating the levels of IAP.
A 9-year-old girl with Down syndrome had bilateral congenital coloboma of the macula. She was born after an uneventful pregnancy, and the results of a Toxoplasma dye test were negative. We concluded that the condition in this patient was a rare occurrence of Down syndrome with macular coloboma.
Cathepsin D has been believed to play an important role in the catabolism of protein in various tissues. In retinal pigment epithelium, cathepsin D degrades rod outer segments and rhodopsin into glycopeptides. To our knowledge, no reports have described the immunohistochemical localization of cathepsin D in whole ocular tissues. We investigated the reaction of bovine, rat, and human eyes with a polyclonal antibody to cathepsin D from bovine spleen. Cathepsin D immunoreactivity was observed in the cytoplasm of the following cells: epithelium and endothelium of the cornea; keratocytes; pigmented and nonpigmented epithelium of the ciliary body; epithelium and cortex of the lens; epithelium and sphincter and dilator muscles of the iris; Müller cells; ganglion cells and pigment epithelium of the retina; and endothelium of various vessels. Positively stained ocular tissues were believed to have a high activity of protein catabolism. Since cathepsin D was closely associated with phagosomes in retinal pigment epithelium, we concluded that cathepsin D probably contributes to the physiologic degradation of rod outer segments.
Thirty seven patients with sarcoidosis were examined using ultrasound (US) to determine the size of the spleen. A Spleen Index (SI) was employed to evaluate splenomegaly and the SI was calculated using long (a) and short (b) dimensions on the sectional splenotomogram (SI = a x b). In 21 (57%) of these patients the spleen was judged ultrasonographically to be enlarged (SI 30), but in only 3 was it palpable. The clinical records of patients with and without splenomegaly detected by US were compared. There were no differences between patients with or without splenomegaly in hematologic findings (peripheral blood and bone marrow) or blood chemistry; furthermore no patients with hypersplenism were seen. In immunological parameters, the serum immunosuppressive acid protein level was significantly (p less than 0.05) higher in patients with splenomegaly than in those without splenomegaly; however, there were no differences in serum angiotenins converting enzyme activity, serum lysozyme level, PPD skin test or bronchoalveolar lavage fluid analysis. The patients with splenomegaly had significantly higher evidence of increased uptake of 67-Gallium in lung fields and positive lung infiltrates in chest X-ray than those without splenomegaly (p less than 0.01, p less than 0.05). These data suggest that ultrasound is a promising diagnostic tool for the assessment of the size of the spleen and is useful to detect disease activity and extent of disease in sarcoidosis. Patients with sarcoidosis who had splenomegaly had more disseminated disease, especially pulmonary parenchymal disease, than did those without splenomegaly.
To decrease both the intensity of the exciting light and the amount of sodium fluorescein, we attached a compact image intensifier incorporating a microchannel plate with a fundus photoscope and tried to record video-fluorescein angiography with low steady light. We preliminarily examined the relationships of exciting and emitted light intensity with various concentrations of sodium fluorescein. The strongest fluorescence was obtained with a concentration of 0.01 mg/ml solution of sodium fluorescein. When the compact image intensifier was attached to the equipment, the exciting light intensity could be decreased to 1/300 with an exciting filter of lambda max of 486 nm. When sodium fluorescein of 0.01 mg/ml solution was injected directly into the heart of Rana catesbeiana, complete video-fluorescein angiography with sufficient brightness and resolution was possible. With the same machine, we recorded video-fluorescein angiography in a normal human subject with injection of 5 ml of 10% sodium fluorescein. The ordinary observing light of the machine was strong enough for video-recording. This exciting light intensity caused no trouble and elicited no complaint from the examinee. These results showed that the use of a compact image intensifier incorporated microchannel plate with a fundus photoscope made it possible to record video-fluorescein angiography and to decrease exciting light intensity and the amount of fluorescein dye. This means that light damage to photoreceptors by exciting light and problems induced by allergic reaction with fluorescein dye might be decreased. These aspects might be very important to obtain information about both retinal circulation and disruption of the blood-retinal barrier and also to perform safe fluorescein angiography examination.
Using newly invented method for collecting vitreous samples, we examined the permeability of antibiotics across the blood-ocular barrior in human eyes. One of the advantages of the present method is that it yields sufficient amounts of sample. This makes it possible to examine and compare the permeability of multiple drugs with the same sample. We studied two antibiotics, Flomoxef Sodium (FMOX) and Cefamandole Sodium (CMD) with proliferative vitreoretinopathy (8 cases), proliferative diabetica retinopathy (8 cases) and simple vitreous haemorrhage (9 cases: including 3 cases of Terson's syndrome). A considerable amount of FMOX was detected in the vitreous sample and the permeability of FMOX was 50% better than that of CMD. Permeability also differed recording of different ocular diseases. The amount of the drug was lowest in cases with simple vitreous hemorrhage, especially in Terson's syndrome (p less than 0.05). This is reasonable as the blood-ocular barrior must be less disturbed in this disease than the other two conditions.
We examined diurnal variations of intraocular pressure (IOP) before and after scleral encircling, vitrectomy and silicone oil (S.O) tamponade in 7 patients (7 eyes) with proliferative diabetic retinopathy (PDR), and 8 patients (8 eyes) with proliferative vitreoretinopathy (PVR). They were all successfully operated and the IOP was lower than 24 mm Hg without medication. The contralateral, non-operated eye was used as the control. IOP was measured every 4 hours with Goldmann applanation tonometer or a pneumotonometer (Alcon) by the single examinee (S.H.). The amplitudes of the diurnal variation of the IOP with S.O. tamponade were smaller than those of the control eyes (p less than 0.05). Phakic eyes with silicon oil tamponade showed smaller amplitudes of IOP diurnal variation than those in aphakic eyes (p less than 0.05). The physiological significance is not clear yet, but these results suggest that the S.O. tamponade have some effect on the dynamics of the intraocular fluid in operated eyes (p less than 0.05).
Immunosuppressive acidic protein (IAP) is a useful tumor marker for evaluating clinical course, therapeutic effectiveness, and prognosis of patients with various malignant tumors. In this report, we examined the serum IAP levels in 20 patients with retinoblastomas. In 6 cases, both preoperative and postoperative IAP values were examined, and in 14 cases the levels of this protein were postoperatively followed. Although 2 of 6 cases had higher levels of IAP than 500 micrograms/ml preoperatively, they had decreased within the normal range (less than 500 micrograms/ml) postoperatively. The mean IAP levels at 1-2 weeks before, 1-2 weeks after and 1 month after surgery were 422 +/- 225.1 micrograms/ml, 221 +/- 62.6 micrograms/ml, and 297 +/- 89.8 micrograms/ml, respectively, that means IAP decreased after enucleation. In 14 cases in which this protein was examined only postoperatively the value was 314.5 +/- 91.6 micrograms/ml. In one case with a level of 856 micrograms/ml of IAP before enucleation, pathological examination revealed invasion of retinoblastoma cells to the optic nerve and orbital fat. The high level of IAP might be related to the extraocular invasion. Since the level of serum IAP decreased after enucleation, these results suggested that immunological activities might change, even though tumor cells grew within the blood retinal barrier.
Gyrate atrophy of the choroid and retina is a rare inherited form chorioretinal degeneration caused by a deficiency of ornithine aminotransferase. We localized the enzyme in human ocular tissues using immunocytochemical procedures. Immunoreactivity was observed in the nonpigmented epithelium of the ciliary body and lens epithelium. In the retina, ganglion cells and some amacrine cells were immunoreactive. Pigmented granules made it difficult to identify immunoreactive products in the iris, pigmented epithelium of the ciliary body, choroid, and retinal pigment epithelium. Our findings suggested that ornithine aminotransferase plays an important role in ornithine metabolism in these oculartissues.
We report a case of benign prostatic hyperplasia in a 60-year-old patient who had been castrated when he was 30 years old. The prostatic tissue, which consisted of cystic and fibromuscular hyperplasia, contained no significant concentration of androgen receptors. Only 1 such case was reported previously in the literature.
Canarium album has yielded seven triterpenes of which two appear to be novel. The new triterpenes, which were identified on the basis of spectral characteristics, are urs-12-ene-3 alpha, 16 beta-diol and olean-12-ene-3 alpha, 16 beta-diol. Both compounds exhibited hepatoprotective activity in primary cultured rat hepatocytes intoxicated with D-galactosamine.
A 47-year-old Japanese man had a progressive degeneration of the retina and choroid along the retinal veins associated with uveitis of two years' duration. The lesion was characteristic of paravenous retinochoroidal atrophy: a contiguous atrophy of the retinal pigment epithelium and choroid of one-half to one disc diameter in size was present along most of the veins from the posterior pole to the far periphery. Fluorescein angiography showed a window defect in the retinal pigment epithelium, with hyperfluorescence representative of retinal pigment epithelium and choriocapillaris degeneration. Good visual acuity was attained after extracapsular cataract extraction for complicated cataract and vitrectomy for severe vitreous opacity had been performed in both eyes. The cause of this new inflammatory disease was unknown.