Mucopolysaccharide in perilymph.
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Animals↗
Biomedical subjects
K Makimoto
Publications and source records attributed to K Makimoto.
Stereoscopic display of a three-dimensional image of the larynx using high-speed helical scanning.
To evaluate the usefulness of stereoscopic images of larynges using helical CT in stereo mode, a retrospective review of the characteristics of stereoscopic viewing of larynges was made. The subjects were 3 patients with laryngeal cancer, 1 patient with laryngeal leiomyosarcoma and 1 patient with an advanced tongue carcinoma whose formalin-fixed larynx was extirpated. The larynges were scanned by high-speed helical CT using 1- to 2-mm slices. The reproduction of stereographic images was performed by the manipulation and rotation of three-dimensional structures around the y-axis on the computer display. The three-dimensional images of the complex structures, such as the arytenoid cartilage, aryepiglottic fold and pyriform sinus, were better observed by binocular images (stereograms) than by monocular images. Stereoscopic views of the larynx are useful in producing three-dimensional images of the unseen inner surface of the human body.
Adult↗
Overexpression of p53 protein and proliferative activity in colorectal adenoma.
Overexpression of p53 was studied immunohistochemically in colorectal tumors. We found p53-positive cells in 17 (58.6%) of 29 specimens of cancer in adenoma. Expression of p53 protein was detected in the nuclei of the tumor cells. We also found p53-positive cells in 7 (7.1%) of 99 specimens of adenoma. p53 immunoreactivity for severe dysplasia was higher than that for mild or moderate dysplasia. p53 expression in adenomas was restricted to a few glands, and the proliferating-cell nuclear antigen (PCNA)-positive rate for the p53-positive glands was significantly higher than that for p53-negative glands. The results suggested that the p53-positive glands might have high growth fractions, and that immunohistochemical detection of p53 expression in tubular adenomas might contribute to identifying the potential for malignant transformation.
Adenoma↗
Effects of hyperventilation and hypoventilation on cochlear blood flow and endocochlear direct-current potential.
To understand the importance of oxygen transport to the inner ear tissue, we studied, in guinea pigs, the relationship between cochlear blood flow and endocochlear direct-current potential (EP) under different respiratory conditions. EP, a functional parameter of the stria vascularis, was recorded by a microelectrode inserted into the lateral wall of the chochlea. To measure the cochlear blood flow (CoBF), we employed laser Doppler flowmetry and recorded the flow with a probe placed on the same spot on the lateral wall. During 3 min of asphyxia, CoBF and systemic blood pressure showed irregular biphasic increases, while the EP decreased to reach a negative value. In the hypoxemia experiment, which was induced by stepwise reduction of the respiratory rate to 60%, increases in CoBF and blood pressure were evident during hypoventilation with an intermediate position of EP in the positive range. The mechanisms of these increases in two parameters are discussed from the viewpoints of sympathicotonic activity in the autonomic nervous system and the vasodilating action of CO2 during hypercapnia. In the hyperoxemia experiment, which was induced by stepwise increase in the respiratory rate to 140%, CoBF and blood pressure were found to decrease during hyperventilation with no significant change of EP. The decrease in blood pressure was considered to be due to the increase in intrathoracic pressure caused by the increased rate of artificial respiration. As for the concomitant decrease in CoBF, chemical regulation of PCO2 in the vascular bed of the lateral wall of the cochlea was thought to be a contributory factor.
Animals↗
Ultrasonic Doppler assessment of hemodynamics in gradual carotid ligation.
Hemodynamic changes were examined with an ultrasonic Doppler flowmeter and with a sound-spectrograph in 5 patients with internal carotid giant aneurysms or with recurrent laryngeal cancer undergoing gradual carotid occlusion. The ultrasonic Doppler technique was useful for preoperative assessment of intracranial cross-filling and as a practical guide for the graded reduction of blood flow in the carotid artery. The degree of flow increase in the contralateral carotid artery when the ipsilateral carotid artery was totally occluded was greater in postoperative gradual occlusion than in intraoperative rapid occlusion. In one patient with bilateral internal carotid artery giant aneurysms, whose left internal carotid artery had already been ligated at its origin, gradual occlusion of the right internal carotid artery was performed after the bilateral superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses. Flow in the donor artery of the right STA-MCA anastomosis developed with increasing occlusion of the right internal carotid artery.
Adult↗
Sodium and potassium concentrations in the endolymph and perilymph of the cat.
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Animals↗
Effect of phlorizin on glucose transport in the inner ear.
14C-glucose was used as a tracer to study the effect of phlorizin on glucose transport into perilymph and endolymph. The transport was found to be lowered in phlorizin-injected animals compared with that in normal controls. This inhibitory effect corresponding to a phlorizin-sensitive part of glucose transport was greater in the perilymphatic system than in the endolymphatic system. Pathways which are not affected by phlorizin, are considered to exist in both compartments of perilymph and endolymph.
Animals↗
Effect of glycerol on the EP decrease caused by furosemide.
A change in endocochlear potential (EP) following furosemide injection was observed in regard to prior glycerol administration in two groups of guinea pigs. In one group, various doses of furosemide (20, 30, 40, 50 mg/kg) were injected, while in the other, glycerol (50 v/v %, 1 ml/kg) was injected prior to the furosemide (20, 30, 40 mg/kg) injection. In the glycerol-furosemide group, the decrease in EP was 40% greater than in the furosemide group. Therefore, glycerol was thought to potentiate the EP lowering action of furosemide. Such an effect of glycerol was assumed to be resulted by facilitating the access of furosemide to the site of action in the stria vascularis.
Action Potentials↗
Effects of reserpinization on the electrolytes distribution in inner ear fluids of guinea pig.
Reserpine (2 mg/kg and 10 mg/kg, i.p.), an adrenergic blocker, was administered to normal guinea pigs, and samples of serum, CSF, scala tympani perilymph, scala vestibuli perilymph and cochlear endolymph were collected. The concentrations of Na and K in these fluids were then assessed to observe electrolyte distributions. Both Na and K concentrations were reduced in serum. In CSF, the Na concentration was markedly depressed, while the K concentration remained unchanged. Scala tympani perilymph showed a pattern of electrolyte changes similar to that in CSF. In scala vestibuli perilymph, the Na concentration was unaltered, but the K concentration was lowered. Cochlear endolymph exhibited no change of the Na concentration but there was a marked decrease in the K concentration. These changes are thought to be attributable to the indirect blockage of energy producing systems in membrane transport in the inner ear by the reserpine-induced depletion of catecholamines.
Animals↗
Effect of glycerol on furosemide-caused EP decrease in guinea pig neonates.
Furosemide, a loop diuretic, reduces the endocochlear potential in guinea pigs. In our previous experiment using adult guinea pigs, glycerol was thought to open the blood-cochlea barrier and to help furosemide to reach its site of action in the stria vascularis. The present study was designed to determine whether or not the same potentiation by glycerol occurs in neonate guinea pigs. In one group, furosemide (10-30 mg/kg) was administered, while in another group, 50 v/v% glycerol (1 ml/kg) was administered 15 minutes prior to the injection of furosemide. Furosemide reduced the EP significantly more in neonates than in adults. This effect was not potentiated in the glycerol-pretreated group. From these findings, it seemed conceivable that the neonate blood-cochlea barrier still remains immature in some functions.
Animals↗
Effects of intravenous glycerol injection on inner ear fluid electrolytes.
Under sodium pentrobarbital anesthesia (20-30 mg/kg, i.p.), normal guinea pigs received an intravenous injection of glycerol (1.0 ml/kg). Serum, cerebrospinal fluids (CSF) and inner ear fluids were collected from the scala tympani perilymph, scala vestibuli perilymph and the scala media endolymph. The sodium and potassium concentrations were assessed using microflame photometry. Increases in sodium concentration were found in the CSF and the scala tympani perilymph; no significant changes were observed in the serum, scala vestibuli perilymph or the scala media endolymph. These sodium increases were considered to be a result of the dehydration process caused by the osmotic agent glycerol. Increases in potassium concentration were found only in the scala vestibuli perilymph.
Animals↗
The developing electrolytes concentrations of inner ear fluids in guinea pigs.
Cochlear endolymph, scala tympani perilymph, and scala vestibuli perilymph were collected from fetal, neonatal, and mature guinea pigs. The concentrations of Na and K in these fluids were then assessed using a microflame photometer. The electrolyte composition in the endolymph was already characterized by a high concentration of K and a low concentration of Na by the 49th day of gestation.
Animals↗
Cell kinetic study on experimental tongue carcinoma in rats.
Tongue carcinomas were produced in rats by oral administration of 0.001% 4-nitroquinoline 1-oxide (4NQO) in drinking water, and the biological characteristics and tumor kinetics were correlated. Bromodeoxyuridine (BrdU) was used to investigate cell kinetics of rat tongue tumors in vivo. BrdU-labeled S-phase cells were demonstrated by an indirect peroxidase method using anti-BrdU monoclonal antibody, and their percentage, the labeling index (L.I.), was determined. The average BrdU L.I. in normal tongue epithelium, well differentiated and moderately differentiated squamous cell carcinoma was 5.7 +/- 1.1, 8.8 +/- 3.7 and 14.9 +/- 5.4, respectively. The differences among the three groups are significant. These results indicate that the BrdU L.I. correlates well with the degree of differentiation of tongue epithelium. Furthermore, the distribution patterns of BrdU-labeled cells in the tissue sections of each group were different. If these cell kinetics studies using BrdU are applied to human tongue carcinomas, the data may provide information on the biological characteristics and help in establishing the diagnosis and in choosing treatment regimens.
4-Nitroquinoline-1-oxide↗
Effect of peroral glycerol administration on inner ear fluid electrolytes of guinea pigs.
After the oral administration of 50% glycerol (12 mL/kg), serum, CSF and inner ear fluids from scala tympani perilymph, scala vestibuli perilymph, and scala media endolymph were collected from normal guinea pigs under sodium pentobarbital anesthesia (25-35 mg/kg). The sodium and potassium concentrations were determined by microflame photometry. Increases in sodium concentrations were found in CSF, scala tympani perilymph, scala vestibuli perilymph, and cochlear endolymph. No significant change was observed in the serum. These sodium increases were considered to be due to the dehydration caused by the osmotic action of glycerol. Potassium concentration was increased only in scala tympani perilymph. Oral administration of glycerol was found to be more gradual and effective in dehydration compared to intravenous injection.
Administration, Oral↗