Biomedical subjects
Publications and source records attributed to K Inomata.
We observed a patient with an abnormal bridging vein having a thickened vessel wall and newly formed vessels within it. It was suggested that the former is a phenomenon accompanying capsule formation around hygroma and the latter, indicating recanalization, originates in cells along the luminal side. Our morphological observations provided the reactive pattern of bridging veins against brain damage.
The cutaneous nerves in pedicled flaps lifted from rats backs were studied by electron microscopy for eight weeks. On the rat back, the paniculus carnosus is supplied by cutaneous nerves from C7-8 and T1 and anastomosed with the cutaneous branch of the spinal nerves (T2 to L5), located deeper under the flap. The cutaneous nerves showed degeneration immediately after the flap was raised; four days later, unmyelinated nerve fibers had disappeared. Regeneration was observed at the seventh day. Regenerated axons of the new fibers were presumed to have originated from the few nerves placed centrally and peripherally at the base of flap, through nerve anastomoses.
The effects of postnatal methotrexate (MTX) exposure on the development of synapses in the developing rat hippocampus were examined. The density of E-PTA-stained synaptic junctions per unit area was significantly reduced by MTX exposure either during day 1-5 or 6-10 post partum. It was suggested that administering MTX during the critical period affected the development of synapses in the developing rat brain.
Enrichment of tocopherol by coupled supercritical fluid extraction/preparative supercritical fluid chromatography is described. Wheat germ powder is used as the starting material and is subjected to supercritical fluid extraction with carbon dioxide. The extracted oil containing tocopherols is concentrated and trapped on a silica gel column by reducing the pressure of carbon dioxide. The trapped oil is then eluted and separated on a silica gel column of 20 mm i.d. x 20 mm length. The column effluent is fractionated by monitoring UV absorption at 290 nm. With this method, tocopherol content of the wheat germ is enriched 100-fold.
In order for the role of parotid amylase in starch digestion in the gastro-intestinal tracts of diabetic rats to be clarified, this study investigated the effect of parotid-duct ligation on both amylase secretion from the parotid glands and pancreas into the gastro-intestinal tract and on starch digestion in the gastro-intestinal contents during feedings. In both diabetic rats and control rats, parotid-duct ligation reduced amylase activity in both the parotid glands during fasting and in the gastric contents after feeding. The amylase activity in the intestinal contents after feeding was reduced by parotid-duct ligation in the diabetic rats. Starch digestion in the gastro-intestinal tract after feeding was reduced by parotid-duct ligation in the diabetic rats. The results suggest that most of the amylase activity in the gastric contents and a large part of the amylase activity in the intestinal contents are derived from the parotid glands, and that parotid amylase plays an important role in starch digestion in the gastro-intestinal tracts of diabetic rats.
We developed the light cured direct relining material and used it clinically. In this study, a partial change in its components was made to improve both its strength and manipulability with the aim of using it as a denture base material. The physical properties of the new material, bonding to resin teeth, fit, as well as procedure were discussed. As for physical properties, the bending strength of the new material was increased by improving its organic filler, it becoming comparable to that of heat curing resin. The water absorption of the new material was the lowest of compared materials. The bonding strength of this material to resin teeth was increased by treatment with a light cured bonding agent and the fit of the new material to a test model was comparable to that of heat curing resin. Thus, the new material seems to be quite clinically effective as a denture base resin.
We performed an ultracytochemical study of Mg++-ATPase as a marker of maturation in circumventricular capillaries at the developmental stage of rats, from 19 gestational days to 18 postnatal day, comparing with hippocampal capillaries. During the course of perinatal development, the predominant site of the Mg++-ATPase activity in circumventricular capillaries was shifted from the luminal cell membrane to the antiluminal cell membrane and the total enzyme activity was markedly increased. In all hippocampal capillaries observed, the predominant site of the Mg++-ATPase activity was the antiluminal cell membrane. It was suggested that immaturity of circumventricular capillaries may be one of the causative factors leading to intraventricular and subependymal hemorrhages in neonates.
The E-PTA-stained synaptic junctions in the adult rat frontal cortex were examined with high-voltage electron microscopy (HVEM). Perforated whole synaptic junctions were clearly shown in the stereo image. The E-PTA staining procedure provides a useful marker for studies of the 3-dimensional structure of synaptic junctions by means of HVEM.
The dehydration condensation of glycine with trimetaphosphate in aqueous solution has been reinvestigated. Although it has been reported that the condensation of glycine under the alkaline conditions was brought about through the formation of cyclic acylphosphoramidate and hence the condensation of polyglycines could not occur, we found that the condensation of oligoglycines with trimeta- and tetrametaphosphate in aqueous solution are possible through the formation of their acylphosphates under the neutral or weak acidic conditions. Aqueous solutions of 1.0 M glycylglycine and 1.0 M trimetaphosphate in the various pH from 4.0 to 9.0 were incubated at 38 degrees C. The solutions were analyzed by HPLC with ninhydrin reaction system. Tetraglycine and hexaglycine were detected and their maximum yields were given in the reaction carried out around pH 7. They are approximately 15% and 4% after 30 days, respectively. Analogous experiments were performed with tetrametaphosphate. The results showed a similar pH dependence for the condensation, but the yields were about one-tenth of those of corresponding experiments with trimetaphosphate. Relative rates of dimerization of glycine, diglycine and triglycine in the equimolar concentration were also investigated at pH 6.0 at 38 degrees C. The rates for diglycine and triglycine were approximately twice and four times as large as that for glycine. Relevance of the experiments to chemical evolution is discussed.
We attempted to identify synaptic glomeruli in the spinal substantia gelatinosa of rats by injecting distilled water into the subarachnoid space. The altered synaptic glomeruli were visualized when injecting 1.0 ml of distilled water, though the incidence of degenerative synaptic glomeruli was rare in the case of an injection of 0.5 ml or less. We assume that when the distilled water is injected, there is a sudden change in homeostatic balance in cerebrospinal fluid, following inhibition of nerve impulses in the dorsal root and the altered synaptic glomeruli. Ultrastructurally, the injection of distilled water led to a preferential degeneration of synaptic glomeruli derived from the C-fibers.
The synaptic glomeruli of rat cerebellum was investigated at postnatal ages of 1 to 7, 9 and 15 days in an attempt to formulate a morphogenic analysis for synaptic junctional development, using the E-PTA stain for synapses. The synaptic junctions, which are composed of dense projection, intercleft density and postsynaptic band in synaptic glomeruli, were observed at a postnatal age of 6 days. Two types of synaptic junctions, symmetrical and asymmetrical, were recognized.
Parotid and pancreatic amylase secretion into the gastrointestinal tract during feeding was investigated in diabetic rats. In control rats, both parotid and pancreatic amylase activity decreased after feeding, while the amylase activity present in the gastric and small intestinal contents increased. In diabetic rats, parotid amylase activity, although reduced from control levels, decreased after feeding, and amylase activity of the parotid type appeared in the gastric content. Amylase activities in the diabetic pancreas and small intestinal contents at fasting were markedly reduced and did not show appreciable change with feeding. The total amylase activity in the small intestinal contents after feeding was markedly reduced in the diabetic rats, whereas the ratio of parotid to pancreatic amylase was markedly increased. These results suggest that the amylase secreted from the parotid glands into the gastrointestinal tract during feeding acts not only in the mouth and stomach but also in the small intestine of diabetic rats.
As a possible preventative measure for brain dysfunction in the fetal alcohol syndrome, the effect of zinc or vitamin E supplementation together with ethanol on the fetal cerebrum was investigated in rats. Contrary to our previously published data showing the good effect of 0.01% zinc with 30% ethanol on fetuses, the administration of 0.01% zinc with 20% ethanol, 0.03% vitamin E with 20% ethanol or 0.02% vitamin E with 10% ethanol during pregnancy did not result in a good effect on the body and cerebral weights of fetuses on gestational day 21. The development of dendritic branches on frontal cerebral neurons in fetuses was decreased in the order of the control, zinc with ethanol and ethanol groups. The concentration and content of alpha-tocopherol were increased, but those of zinc were not, in the fetal cerebrum with the maternal administration of vitamin E or zinc together with ethanol, respectively. These results suggest that the improvement of the brain function might depend on the deficient agent induced by maternal ethanol ingestion.
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The cytochemical localization of alkaline phosphatase (AlPase) activity in the developing IVth ventricular choroidal epithelium was investigated in embryonic and neonatal rats. During the initial development of the choroidal primodium the flattened and/or cuboidal epithelial cells of the ventricular roof were changed to columnar cells with well-developed microvilli and apical tight junctions. When compared to AlPase activity on the lateral plasma membranes of the surrounding ependymal cells, these columnar cells of the choroidal primodium revealed activity on the lateral and luminal plasma membranes, but no activity was found on the basal surface of these cells. On the other hand, the epithelial cells in the neonatal choroid plexus showed a continuous morphological alteration from columnar cells with short microvilli to mature cuboidal cells with numerous long microvilli. AlPase activity in immature columnar cells was observed on all plasma membranes, except for the apical junctional area of the lateral surface. With maturing of the choroidal epithelial cells, the activity appeared to be eliminated from the lateral and luminal plasma membranes of the cuboidal cells, and mature choroidal epithelial cells showed activity on the basal surface only. These findings suggest that AlPase may play an important role in the membrane activity of epithelial cells differentiating between the primitive epithelial cells of the ventricular roof and the mature choroidal epithelial cells.
We examined the developing synaptic junctions in the rat frontal cortex in cases of fetal alcohol syndrome, the objective being to determine the synapse-mental retardation relationship. On day 21 of gestation, the ultrastructural synaptic junction revealed no obvious differences between the ethanol-exposed and control rats; however, the number of synapses in ethanol-exposed rats was one third that of the controls. The possible relationship between synaptic density in the frontal cortex and mental development has to be considered.
The transitional zone between the myelinated and the terminal portions of nerve fibers was electron microscopically investigated in the cerebellar cortex of normal rats. A noteworthy finding in the present study is the existence of a "heminode" consisting of the myelinated and non-myelinated portions, as demonstrated within a single section. The heminode seems to be a characteristic structure in the granular layer of the rat cerebellar cortex.
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