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Biomedical subjects

E Chihara

Publications and source records attributed to E Chihara.

At least 55 records · Page 3Linked to original sources
PubMed1989

Axonal transport in mdx mouse sciatic nerve.

Anterograde and retrograde flows of acetylcholinesterase (AChE) in sciatic nerves of adult mdx mice were compared with those of normal mice. Specific molecular forms of AChE were resolved by high-performance liquid chromatography such that slow anterograde (G1 + G2), fast anterograde and fast retrograde (G4 and A12) flows could be simultaneously studied. Although we found no difference in the total AChE activity and the molecular forms in non-ligated nerves between mdx and the normal mice, ligated nerves showed significant differences. The total AChE activity accumulated at the proximal segment of ligated nerve was higher in mdx mice than in normal mice after 24 h ligation. The G1 + G2 molecular forms were accumulated more in the proximal segment of mdx than the normal. A12, on the other hand, was more abundant in both segments of mdx mice than the normal. No statistically significant difference in the accumulated amount of G4 molecular form was present between mdx and the normal mice at either proximal or distal segment. These results indicated that axonal flow in sciatic nerve likely plays a role in muscle regeneration, and that the transport machinery in dystrophin-deficient mdx neuron is probably normal.

Acetylcholinesterase↗
PubMed1989

[A newly devised continuous catheter flush system for arterial pressure monitoring].

Since Gardner et al. demonstrated a useful continuous catheter flush system in 1970, various systems for blood pressure monitoring have been commercialized. However, some problems have not been solved yet, such as hazard of embolism, infarction, unexpected infusion of large amount of fluid etc.. We have introduced a new type of flush system. which consists of disposable plastic unit with a one-way valve newly developed by us (SAT-route) and a syringe pump (Terumo STC-521). Using this system, only 0.5 ml.hr-1 infusion of heparinized saline was sufficient to prevent the formation of thrombus. Flushing was easily achieved by only pushing the purge button of the pump. As a result, simple, safe and high fidelity pressure monitoring was achieved without much altering the waveform of arterial pressure during flushing. The dynamic frequency response obtained from a square wave test was excellent, with natural frequency of about 40 Hz and damping coefficient of about 0.3. This system is useful especially for perioperative management of small children undergoing cardiac surgery, who require an exquisite infusion therapy and fluid restriction.

Blood Pressure Monitors↗
PubMed1986

Metabolism of glycoproteins in cultured retinal pigment epithelium.

The turnover and migration of synthesized glycoproteins in the cultured retinal pigment epithelium have been studied. Quantitative study indicated that half-time of 3H-fucosylglycoproteins was 11.6 days. Autoradiography was performed several times after incubation of 3H-fucose. Retinal pigment epithelium constantly synthesized glycoproteins and released them into the basal extracellular material. Possible functions of the glycoproteins are discussed.

Animals↗
PubMed1986

Changes in components of fast axonally transported proteins in the optic nerves of diabetic rabbits.

Proteins synthesized in retinal ganglion cells were labeled with 35S-methionine or 3H-leucine to the vitreous cavity, and the components of fast axonally transported proteins were studied in 20 nerves of 10 normal rabbits and 34 nerves of 17 alloxan-induced diabetic rabbits. Proteins in the optic nerves were separated by SDS-polyacrylamide gel electrophoresis, and axonally transferred proteins were studied by fluorography. In diabetic animals, the axonally transported radioactivity was one-fifth that of the controls. In the fluorographic spectrum of 35S-methionine-labeled proteins, relative proportion of 120kDalton(D)-proteins were increased by 43%, and 29kD proteins were decreased by 65% in diabetic rabbits. Relative proportion of other proteins, such as 24k, 36k, 68k, 150k and 180kD, were the same in control and diabetic rabbits. The quantitative reduction and change in spectrum of fast axonally transported proteins are compatible with the vulnerability and dysfunctions of nerve fibers in diabetic patients.

Animals↗
PubMed1985

Resorption of subretinal fluid by transepithelial flow of the retinal pigment epithelium.

The efficiency of flow through the retinal pigment epithelium (RPE) was calculated by studying the postoperative course of the subretinal fluid after nondrainage surgery of rhegmatogenous retinal detachment. In ten eyes of ten patients the preoperative volume of the subretinal fluid, area of the RPE participating in resorption of the fluid, elapsed time until resorption of the fluid, and efficiency of the flow were studied using B-scan ultrasonography. The flow through the RPE was 261 microliter/cm2 per day and could drain more than 50% of the vitreous volume to the choroidal circulation. These data coincide well with early reattachment of neural retina in nondrainage surgery. No statistically significant difference in this flow was seen between young and old patients.

Absorption↗
PubMed1985

Blockage at two points of axonal transport in glaucomatous eyes.

Blockage of axonal protein transport in intraocular hypertensive primates (Macaca irus) was studied autoradiographically and quantitatively and the findings compared with our previous work on rabbits. Fast axonal transport was blocked at two points, at the lamina scleralis and at the edge of posterior scleral foramen, and reduced by 25% when intraocular pressure of 50 mmHg continued for 6 h. The importance of the blockage at the lamina scleralis and at the edge of scleral foramen for the explanation of paracentral scotomas and the peripheral nasal step (Rønne) is discussed.

Animals↗
PubMed1985

Some experimental data concerning the safety of vitrectomy.

Several reasons why vitrectomy does not compromise retinal functions are shown, based on closed and open-sky vitrectomy on the rabbit eye. We observed that ERG b- and c-waves were stable during and after open-sky vitrectomy. The c-wave disappeared when the retina was detached. Function of the retinal ganglion cells after vitrectomy was shown to be almost normal by electrophysiological studies and by measured amounts of axonally transported radioactive proteins.

Animals↗
PubMed1984

Synthesis of glycosaminoglycans by chick retinal pigment epithelium in vitro.

Cultured chick embryonal retinal pigment epithelial (RPE) cells synthesized two main glycosaminoglycans (GAGs), chondroitin 4-sulfate, and heparan sulfate. Chondroitin 4-sulfate was liberated mainly in the medium (apical side) and heparan sulfate was incorporated into the cell and/or basement membrane. Glycosaminoglycans liberated into the medium were composed of chondroitin 4-sulfate (44%), keratan sulfate (22%), heparan sulfate (18%) and hyaluronate (12%). On the other hand, the GAGs in the cell and/or basement membrane were composed of heparan sulfate (52%), hyaluronate (19%), and chondroitin 4-sulfate (13%).

Animals↗