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Biomedical subjects

Y Taniguchi

Publications and source records attributed to Y Taniguchi.

At least 541 records · Page 30Linked to original sources
PubMed1983

Experimental macular edema of commotio retinae: preliminary report.

Experimental macular edema of commotio retinae was studied in rhesus monkeys. Clinically, opacification of the retina in these experimental animals closely resembled commotio retinae of man. No pigment epithelial damage was detected by ophthalmoscopy and fluorescein angiography showed no leakage from the retinal and choroidal circulations in the macular region. Histologically, macular swelling was apparent and was due primarily to changes of the outer plexiform layer. In this layer, swelling of the axons of the photoreceptor cells was prominent. Intracellular edema was also detected in the Müller cell processes in the inner retina and in the pigment epithelial cells. Prominent changes also occurred in the inner and outer segments of the photoreceptor cells. Disruption of the blood-retinal barrier was not found using horseradish peroxidase as a tracer. We concluded that retinal opacification was due to disagreement and intracellular edema of the cellular elements of the retina, perhaps a direct result of movement of intracellular fluid in response to mechanical injury.

Animals↗
PubMed1983

Early signs of diabetic retinopathy by fluorescein angiography.

The initial sign of diabetic retinopathy is considered to be microaneurysm, determined by ophthalmoscopy. To elucidate early vascular changes in diabetes, fluorescein angiography was performed in 272 eyes of 166 patients who had shown no evidence of diabetic retinopathy by ophthalmoscopy. Early retinal vascular changes shown by fluorescein angiography were seen in 181 eyes (66.5%) out of 272 eyes. These angiographic findings embraced dye leakage, dilatation of capillaries, filling defect of capillaries, microaneurysm-like spot dilatation and microaneurysm. Statistical analysis and follow-up studies for 1 to 5 years revealed that, with progression of the disease, the angiographic changes progressed in the following order: dye leakage, dilatation of capillaries, filling defect of capillaries, microaneurysm-like spot dilatation and microaneurysm.

Adult↗
PubMed1983

Diabetic retinopathy and hemoglobin A1.

A prospective study was conducted in 36 diabetic patients to correlate the fasting blood sugar level (FBS) and the levels of hemoglobin A1 (HbA1) with the severity and progression of diabetic retinopathy. During an average follow-up of 12.6 +/- 2.9 months, the FBS and HbA1 levels were determined and progression of diabetic retinopathy assessed by fluorescein fundus angiography. The time-averaged HbA1 and FBS were correlated significantly. The HbA1 levels were significantly augmented in the order of good, fair and poor sugar control groups. The patients with progressive retinopathy had significantly higher FBS and HbA1 levels than the patients whose retinopathy remained unchanged. The correlation between the HbA1 level and the severity of retinopathy was not statistically significant. It was concluded that the combination of HbA1 and FBS levels will be useful for long-term control of diabetes and of progression of retinopathy.

Adult↗
PubMed1982

Characterization of human peripheral blood T lymphocytes bearing receptors for autologous erythrocytes and T lymphocytes lacking these receptors.

When human T cells were treated with neuraminidase from Vibrio cholerae, the capacity of T cells to form rosettes with autologous erythrocytes was markedly enhanced. The neuraminidase-treated T cells wee separated with autologous erythrocytes into autorosetting and nonrosetting cell populations, and these two populations examined for their reactivity to mitogens and B cells and for their regulatory activities. Autorosetting T cells proliferated poorly in response to mitogens and autologous and allogeneic B cells; these cells were particularly enriched for cells capable of becoming concanavalin A-induced suppressor cells. Nonrosetting T cells capable of most actively proliferating in response to the mitogens and the B cells failed to exhibit such suppressor function after concanavalin A activation. Coculture experiments between autorosetting and nonrosetting cells further demonstrated that the nonrosetting T cells were able to potentiate the proliferation of the autorosetting T cells with concomitant expression of the suppressor properties.

Antibodies, Monoclonal↗
PubMed1982

Disruption of iridial blood-aqueous barrier in experimental diabetic rats.

The permeability pattern of iridial blood-aqueous barrier in streptozotocin-diabetic rats, maintained for 1-6 months, was studied with the light and electron microscopes, using horseradish peroxidase as a tracer. A reaction product of horseradish peroxidase was confined to the vascular lumina and to a small number of vesicles on the luminal portion of the endothelial cells in control rats and diabetic rats maintained for 1 month. In diabetic rats maintained for 2-6 months, endothelial cells contained a large number of horseradish peroxidase-labeled vesicles which opened into the basement membrane, and intercellular junctions of the endothelial cells were filled with horseradish peroxidase. Horseradish peroxidase was consistently found in the stroma around the vessels, and seemed to reach the anterior chamber through the intercellular spaces between the fibroblasts. However, the passage of horseradish peroxidase was blocked by the posterior epithelial cells.

Animals↗
PubMed1982

Sequential morphological studies of the esophageal carcinoma of rats induced by N-methyl-N-amylnitrosamine.

N-Methyl-N-amylnitrosamine was given to male Wistar rats in the drinking water at a concentration of 0.003% for 8 weeks. Three rats were autopsied weekly from the first to the 25th week. The stages of hyperplasia, dysplasia and squamous cell carcinoma in the esophagus were chronologically observed. Hyperplasia and dysplasia were found by the 6th week and continuously observed until the end of the experiment. Early squamous cell carcinomas were found in the 13th week. They showed endophytic or exophytic growths. Histologically, the endophytic growths were well-differentiated squamous cell carcinomas and the exophytic growths were poorly-differentiated. Advanced carcinomas were first found in the 15th week and were almost well-differentiated. Carcinomas were not found in papillomas. The incidence of carcinomas increased with time, being 9 out of 15 rats (60%) in the final 21st through 25th weeks. Lymph node metastasis was found in one rat, killed at the 24th week.

Animals↗
PubMed1982

Production of polyvinyl alcohol oxidase by a symbiotic mixed culture.

Production of polyvinly alcohol (PVA) oxidase by Pseudomonas sp. strain VM15C, a PVA degrader of a symbiotic PVA-utilizing mixed culture, was examined in various cultures. Despite the absence of PVA in the culture in nutrient broth, VM15C showed approximately the same productivity of PVA oxidase activity as that in the culture with PVA as the sole carbon source, whereas the productivity in the culture with glucose was lower than that of either the nutrient broth or the PVA culture. PVA oxidase activity produced in the nutrient broth culture was predominantly present in the cells, and most of the activity appeared to be in the cytoplasm. In contrast, in the culture with PVA as the sole carbon source, the activity was present in the culture fluid in a larger ratio than in the nutrient broth culture. Thus, production of PVA oxidase activity by this strain was constitutive and repressible, although localization of the produced activity was changed by growth conditions.

Journal Article↗
PubMed1982

Retinal vascular patterns in the macula and the perimacular area in premature and full-term infants.

27 eyes of 20 premature and full-term infants were subjected to trypsin digestion, and a study was made of the extension of the temporal retinal vessels and of the formation of the radial peripapillary capillaries (RPCs) and the capillary-free zone in the macula. The advancing borders of the temporal retinal vessels exhibited a V-shaped appearance in cases of 23-29 weeks in gestational age. The RPCs were observed in cases after the 27th week of gestation. The capillary-free zone in the macula was observed in cases after the 25th week of gestation. There were two eyes having extremely small and incomplete capillary-free zones: in one eye a vascular network was present in the region corresponding to the center of the macula. It was thought that the vascular network in the temporal horizontal aspect of the macula is formed by anastomosis of the superior and inferior temporal vessels, and that the capillary-free zone in the macula develops secondarily as the result of retraction of the capillaries.

Gestational Age↗
PubMed1982

Identification of microglia cell of the rat retina by light and electron microscopy.

Distribution of microglia cells was studied in the normal retina of Wistar rats kept in a specific-pathogen-free condition, using a combined technique of light and electron microscopy with the weak silver carbonate staining method of del Rio-Hortega. Typical microglia cells were found mainly in the inner plexiform layer. By electron microscopy these cells were easily identified by metallic deposition in the cells, and had a small oval nucleus with a prominent chromatin pattern, which was one of the most characteristic features of the cell. Based upon these fine structures, microglia cells were identified in the nonimpregnated, ordinarily prepared retina by electron microscopy. These cells contained lysosomes, lipofuscin granules, Golgi apparatus, and long, narrow cisternae of rough-surfaced endoplasmic reticulum mainly at both sides of the perikaryon. These features were identical with those of microglia cells in the central nervous system. Microglia cells were found to be widely distributed in the inner portion of the retina, most of the cells locating closely to ganglion cells or capillary walls, and occasionally in the inner plexiform layer. The nuclear feature of the cell was also recognizable by light microscopy in 1-micron-thick Epon sections stained with toluidine blue. Serially cut thick sections of the retinal ribbon revealed that microglia cells were widely distributed from the peripapillary to the ora serrata region. From the present study, it is concluded that the microglia cell can be considered a component of the normal retina. This is the first report on the precisely described fine structures of the retinal microglia cells.

Animals↗
PubMed1982

[Effect of nitroglycerin on epicardial and endocardial shortening characteristics in dogs].

In 8 dogs, several paired lead beads as radiopaque markers were implanted in the subepicardial and subendocardial regions, and biplane cineradiograms were obtained after closure of the chest. The spatial distance (segment length) between the two markers in the outer and inner sides of the myocardium was calculated using a digitizer-computer-plotter system, and the effect of nitroglycerin on regional left ventricular geometry was assessed. Segment length at the R wave of the electrocardiogram (LECG R) was reduced from 39.7 +/- 11.8 (mean +/- SD) to 38.8 +/- 12.1 mm at the subepicardium and from 31.9 +/- 9.5 to 29.5 +/- 10.4 mm at the subendocardium 3 minutes after intravenous injection of 0.5 mg of nitroglycerin. Segment length at endsystole (LES) was also reduced from 38.9 +/- 11.7 to 38.2 +/- 11.8 mm at the subepicardium and from 29.6 +/- 9.2 to 27.9 +/- 9.9 mm at the subendocardium by nitroglycerin. Systolic shortening [(LECG R--LES)/LECG R] x 100) showed a slight reduction after nitroglycerin. Left ventricular wall thickness measured as a distance between subepicardial and correspondent subendocardial markers showed a slight but significant increase by nitroglycerin: Maximal thickness was increased from 10.9 +/- 3.2 to 11.4 +/- 3.3 mm, and thickness at the R wave of the electrocardiogram was also increased from 10.9 +/- 3.1 to 10.5 +/- 3.2 mm. Thickening of the wall was markedly increased at the anterior mid portion of the left ventricle but not at the base, suggesting nitroglycerin has larger effect on the former position than the latter.

Animals↗
PubMed1982

Optic disk drusen with central retinal artery occlusion.

An 18-year-old Japanese boy with optic disk drusen associated with left central retinal artery occlusion was reported. Transient central blurred vision, possibly caused by central retinal artery spasm, was noticed as an initial symptom of optic disk drusen in the left eye. Prolonged and repeated spasm might have given rise to a central retinal artery occlusion followed by neovascular glaucoma. The relationship between drusen in the disk and intrapapillary circulation disturbances was discussed.

Adolescent↗
PubMed1982

[Difference of the shortening characteristics between left ventricular endocardium and epicardium as measured by radiopaque markers in experimental dogs].

This study was performed to clarify the difference of shortening characteristics between left ventricular epicardium and endocardium. Four to five pairs of radiopaque markers (lead beads, phi 0.3- 0.8 mm) were implanted just beneath the epicardium and endocardium, respectively in eight open-chest dogs. After the pericardium and thorax were closed, biplane cine-roentgenograms were obtained. The spatial distance (segment length) between any two of the markers was calculated using a digitizer-computer-plotter system. Left ventricular wall thickness (Th) was measured as a distance between epicardial and endocardial markers. The maximum left ventricular thickness (Thmax) was 9.4 +/- 3.4 mm (mean +/- SD), the minimum (THmin) 8.4 +/- 3.1 mm, and a percent increase of wall thickness [(Thmax-Thmin)/Thmin] was 12.7 +/- 6.5%. The value of epicardial segment length divided by endocardial segment length as normalized by each length at R wave of ECG was 1.088 +/- 0.071 at the end of systole and 0.979 +/- 0.016 at end diastole, indicating that endocardial segment shortened and distended more than epicardial segment during systole and diastole, respectively. Epicardial segment began to shorten 3 +/- 26 msec earlier and distend 4 +/- 50 msec earlier than endocardial one. This study revealed a small but consistent difference in the amount of shortening and its initiation and termination between the epicardium and endocardium.

Angiocardiography↗