Biomedical subjects

K Fukazawa

Publications and source records attributed to K Fukazawa.

At least 37 records · Page 2Linked to original sources

PubMed1999

[Local injection of dexamethasone acetate suspension into the nasal mucosa in cases of olfactory disturbance].

Local injections of suspended steroid solution into the nasal mucosa were performed for 102 patients with olfactory disturbances. Dexamethasone acetate suspension in a concentration of 4 mg/0.5 ml was injected into the mucosa of the nasal septum on each side every 2 weeks for a total of 8 times. Mecobalamin and ATP were also administrated in a daily dose of 750 micrograms and 300 mg, respectively. Of the 102 olfactory disturbance patients, 32 patients had chronic sinusitis, 24 patients had common cold, 14 patients had allergic rhinitis, 9 patients had head trauma and the remaining 23 patients the reason for the disturbance was unknown. Using a visual analogue scale, improvements were found in 63.7%. We assessed the effect of this therapy on the threshold of olfactory sensation and perception using a T & T olfactogram. The overall mean values of olfactory sensation and perception were significantly improved; from 4.75 +/- 1.44 (SD) to 3.01 +/- 2.13 (SD) and from 5.30 +/- 0.88 (SD) to 4.19 +/- 1.60 (SD), respectively. All but the cases of head trauma showed significant improvement. Overall, 44 (43.1%) of the 102 patients were defined as having had a positive olfactory response to this treatment (an improvement in the average perception olfactory score of > = 1.0). In cases of chronic sinusitis, 15 (46.9%) of the 32 patients were positive. 12 (50.0%) of the common cold 24 patients, 7 (50.0%) of the 14 allergic rhinitis patients, 2 (22.2%) of the 9 head trauma patients and 11 (47.8%) of the 23 unknown etiology patients were positive for this treatment. Patients with severe olfactory dysfunction and anosmia showed a lower response than the patients who were mildly to moderately affected. Patients showing no response in the Alinamin intravenous test showed also lower improvement rates than those showing a normal response. Interestingly, 8 (27.6%) of 29 patients with a normal appearance of the olfactory clefts and no response for the Alinamin test responded positively to this treatment. This meant that the olfactory disturbance might be due to the existence of edema surrounding the olfactory nerve, not of the olfactory cleft. The improvement rate of patients treated within one year from the onset of these olfactory disturbance was better than the rate of those over one year. The present new therapeutic modality is very useful as a treatment which showed only be performed by otolaryngologists.

Adenosine Triphosphate↗

PubMed1999

[Antimicrobial resistance testing of H. pylori epsilometer test and disk diffusion test].

The resistance of Helicobacter pylori to antibiotics leaves great influence on treatment outcome. Routine antimicrobial susceptibility testing of H. pylori should be a simple, inexpensive and standardized method to be adopted. Agar and broth dilution techniques are difficult to perform and not practical. E-test and disk diffusion methods have the advantage of allowing the visualization of resistant subpopulations of bacteria within zones of inhibitions. We studied the susceptibility results of 246 H. pylori isolates against metronidazole and clarithromycin using E-test and disk diffusion test. The results of disk diffusion test were well correlated with these of E-test. Our results showed that disk method is cost effective and simple for the screening for antimicrobial resistance of H. pylori.

Clarithromycin↗

PubMed1998

Failure of forskolin to elevate the endocochlear potential in experimental endolymphatic hydrops of the guinea pig.

The effect of forskolin (FSK) on the endocochlear potential (EP) in scala media (SM) was examined in experimental endolymphatic hydrops of the guinea pig. Two weeks after obliteration of the endolymphatic sac the EP of hydroptic ears and that of the contralateral control ears were measured by means of microelectrodes. The perfusion of scala vestibuli (SV) with FSK (200 microM) produced EP elevation in the contralateral control ears but failed to do so in the experimental hydroptic ears. Histological examination of experimental endolymphatic hydrops showed mild hydrops with intact appearance of outer and inner hair cells, and the stria vascularis. The mechanism underlying the failure of FSK to elevate the EP in experimental endolymphatic hydrops is discussed.

Animals↗

PubMed1996

Cytochemical effects of in vitro dopamine treatment on the Na-KATPase activity in strial marginal cells.

Dopamine is often used clinically for the treatment of patients with shock. In a previous study, the Na-KATPase (K-NPPase) activity of strial marginal cells was inhibited after the repeated in vivo administration of dopamine hydrochloride. In the present study, the K-NPPase activity of strial marginal cells was determined using a cerium-based cytochemistry after an in vitro incubation with dopamine. The enzyme reaction product was found in untreated normal strial marginal cells, but it was almost completely undetectable after an in vitro treatment with 10 mM dopamine. This finding suggested that dopamine directly inhibited the Na-KATPase activity of strial marginal cells, and that these cells might have a dopamine receptor.

Adrenergic Agents↗

PubMed1995

Hair cell regeneration in the chick inner ear following acoustic trauma: ultrastructural and immunohistochemical studies.

The regeneration of hair cells in the chick inner ear following acoustic trauma was examined using transmission electron microscopy. In addition, the localization of proliferation cell nuclear antigen (PCNA) and basic fibroblast growth factor (b-FGF) was demonstrated immunohistochemically. The auditory sensory epithelium of the normal chick consists of short and tall hair cells and supporting cells. Immediately after noise exposure to a 1500-Hz pure tone at a sound pressure level of 120 decibels for 48 h, all the short hair cells disappeared in the middle region of the auditory epithelium. Twelve hours to 1 day after exposure, mitotic cells, binucleate cells and PCNA-positive supporting cells were observed, and b-FGF immunoreactivity was shown in the supporting cells and glial cells near the habenula perforata. Spindle-shaped hair cells with immature stereocilia and a kinocilium appeared 3 days after exposure; these cells had synaptic connections with the newly developed nerve endings. The spindle-shaped hair cell is considered to be a transitional cell in the lineage of the supporting cell to the mature short hair cell. These results indicate that, after acoustic trauma, the supporting cells divide and differentiate into new short hair cells via spindle-shaped hair cells. Furthermore, it is suggested that b-FGF is related to the proliferation of the supporting cells and the extension of the nerve fibers.

Acoustic Stimulation↗

PubMed1995

Endocytosis and transepithelial transport of endolymph in the endolymphatic sac.

The fate of cationized ferritin (CF) injected into the endolymphatic space of the endolymphatic sac was observed by transmission electron microscopy. At 10 min after the injection, CF particles bound to the apical plasma membrane of epithelial cells of the sac and were then endocytosed with coated pits. However, they never passed through the junctional complexes between the epithelial cells. At 30 min after the injection, the CF particles were transferred to endosomes and lysosomes by small vesicles of 100-150 nm in diameter. CF particles were also found in small vesicles close to Golgi cisternae and in multivesicular bodies. Acid phosphatase positive lysosomes were found close to endosomes containing CF particles. In addition, a small fraction of the small vesicles containing CF particles became inserted into the basolateral plasma membrane. At 60 min after the injection, many CF particles were found in acid phosphatase positive secondary lysosomes. These observations suggest that endocytosis of endolymph is actively performed by the epithelial cells of the sac, and transepithelial vesicular transport across the epithelial cells occurs.

Acid Phosphatase↗

PubMed1995

Vascular permeability of the stria vascularis and morphology of the endolymphatic sac in two types of experimental endolymphatic hydrops.

We produced two kinds of experimental endolymphatic hydrops. One was induced by obliteration of the endolymphatic sac (ES), and the other was induced by both systemic keyhole limpet hemocyanin immunization and secondary keyhole limpet hemocyanin challenge into the ES. The vascular permeability of the stria vascularis in acute and chronic phases was compared between both models by light and electron microscopy using the tracer method of horseradish peroxidase. Both models showed that the number of strial capillaries showing horseradish peroxidase leakage was significantly higher in the acute phase than in the chronic phase. In the acute phase, the ES showed acute inflammation in both models. In the chronic phase, extensive fibrosis occurred in the ES obliteration model, whereas the ES appeared to have a normal shape in the immunologically induced model. The mechanism of hydrops formation will be compared between the two models.

Acute Disease↗

PubMed1995

[Measurement of serum TSH receptor antibodies in thyroid patients using TRAb Dade kits].

TRAb Dade kit is a radioreceptor assay that detects autoantibodies in serum of patients with thyroid diseases which interfere with the binding of 125I labeled TSH to its receptor. In this paper we examined the basic and clinical usefulness of newly developed TRAb assay kits. The intra and inter assay coefficients of variation were 7.9% and 8.4%, respectively. There was no significant effect of temperature and incubation time on TRAb values. The influence of conjugated, unconjugated bilirubin, hemoglobin and turbidity was not so significant on TRAb values. TRAb values in serum of 68 untreated Graves' disease were above the normal range, but most (78%) treated Graves' patients who became euthyroid after receiving antithyroid drug, showed the normal range. In patients with chronic renal failure TRAb values were also within the normal range. A significant correlation (y = 1.0x-0.88, r = 0.95) was observed between this TRAb kit and TRAb Cosmic values in various thyroid conditions. This new assay for TRAb was simple, rapid and reproducible. The measurement of serum TRAb values was useful for the evaluation of physiological and pathological function and seemed to be helpful in the management of patients with thyroid disease.

Autoantibodies↗

PubMed1994

CYFRA 21-1 as a tumor marker used in measuring the serum fragment of cytokeratin subunit 19 by immunoradiometric assay.

Serum levels of cytokeratin subunit 19 (CYFRA 21-1) were measured in 42 healthy volunteers, 104 cases of malignant diseases, 30 patients with chronic renal failure and 13 patients with nonmalignant and infectious diseases. The reliability of the method was demonstrated after dilution of serum samples and intra- and inter-assay reproducibility. Serum CYFRA-21-1 concentrations were less than 2.00 ng/ml in all healthy controls and 86% of the malignant cases had high serum CYFRA 21-1 levels. However slightly elevated values of CYFRA 21-1 were observed in most chronic renal failure patients. High correlation was observed between serum CYFRA 21-1 and Tissue Polypeptide Antigen (TPA) values (r = 0.90, n = 10) but not with serum alpha-feto protein (AFP) concentrations. Furthermore, cross binding tests with the CYFRA 21-1 tracer/CYFRA 21-1 antibody-coated beads and CYFRA 21-1 tracer/TPA antibody-coated beads also gave an almost linear graph. These results indicate that CYFRA 21-1 and TPA share similar type of antigens.

Biomarkers, Tumor↗

PubMed1994

Failure of forskolin to elevate the endocochlear potential in kanamycin-poisoned animals.

The effect of forskolin (FSK) on the endocochlear potential (EP), K+ activity (AK), Na+ activity (ANa) and Cl- activity (ACl) in scala media (SM) was compared between normal and kanamycin (KM)-poisoned guinea pigs by means of double-barrelled ion-selective microelectrodes. The perfusion of the scala vestibuli (SV) with FSK (200 microM) produced EP elevation in normal animals whereas FSK failed to do it in KM-poisoned animals. FSK increased ACl of SM with no significant change in AK and ANa of SM in both groups of animals. Histological examination of KM-poisoned animals showed damaged outer and inner hair cells with an intact appearance of the stria vascularis. The mechanism underlying the failure of FSK to elevate the EP in KM-poisoned animals is discussed.

Animals↗

PubMed1994

Fine structural aspects on auditory hair cell degeneration in the budgerigar, Melopsittacus undulatus, as induced by kanamycin.

The effects of kanamycin, an antibiotic of the aminoglycoside group, on the auditory sensory epithelium of the budgerigar, Melopsittacus undulatus, were examined using both scanning and transmission electron microscopes. Results show that the threshold of the auditory brainstem response increased in birds treated with kanamycin 200 mg/kg for 49 days. While the auditory sensory epithelium of the normal budgerigar consists of short and tall hair cells, and supporting cells, following kanamycin administration, the middle to proximal region of the epithelium of the inner ear showed degenerative changes, with the other parts remaining apparently intact. In the damaged region, the short hair cells were flattened, and the tall ones became heterogeneous in shape. Both types of cells contained many dense bodies in their cytoplasm; they were rounded in shape and homogeneously dense. Severely degenerated tall hair cells also contained many large vacuoles with heterogeneous contents. Because the dense bodies and large vacuoles were positive for acid phosphatase reaction, they were respectively judged to be primary lysosomes and secondary lysosomes containing degenerating cell debris. Most supporting cells in the impaired region were lower in cytoplasmic electron density, and their apical surface became enlarged in area. Some flattened short hair cells were situated on the apical part of the swollen supporting cells. This finding suggests that the short hair cells are pressed toward the scala media by the supporting cells.

Animals↗

PubMed1993

An immunohistochemical and electrophysiological study on Isk protein in the stria vascularis of the guinea pig.

The reaction product against rat Isk protein antibody was demonstrated on the endolymphatic surface of the marginal cell of the guinea pig, using an immunohistochemical method. Clofilium, a potassium channel blocker which has been previously found to block rat kidney Isk channels, decreased the endocochlear potential (EP) when applied by perilymphatic perfusion and iontophoresis into endolymph. This finding of a decreased EP supports the presence of Isk protein on the endolymphatic surface of the marginal cell.

Action Potentials↗

PubMed1993

Morphological aspects of transport of potassium ion in the marginal cell.

Structure and function of the marginal cell in the stria vascularis were studied by freeze-fracture, cytochemistry and immunohistochemistry with special regard to the ion transport of potassium. Freeze-fracture showed that marginal cells were connected by tight junctions beneath the scala media K(+)-NPPase cytochemistry showed that Na+, K(+)-ATPase was abundant on the basolateral infoldings of the marginal cell. Immunohistochemistry of a rat Isk protein, which has a property of a potassium channel, revealed that the rat Isk protein was localized at the endolymphatic surface of the marginal cell. These findings supported the 'one-pump' theory (Offner et al. Hear Res 1987; 29: 117-24).

Animals↗

PubMed1993

The ultrastructure of the basilar papilla of the budgerigar's inner ear.

The basilar papilla in the inner ear of the adult budgerigar was studied by scanning and transmission electron microscopy. The sickle-shaped basilar papilla has short hair bundles on the proximal tip and long ones on the distal tip. The tectorial membrane shows a honeycomb-like pattern and enclosed a hair bundle in its alveolus. The papilla consists of two different types of hair cells; short and tall hair cells. The short hair cells with large efferent nerve endings are located on the free basilar membrane in the inferior part. The tall hair cells with large afferent nerve endings are located in the superior part. The similarity and difference of the structure are discussed between the budgerigar and other birds, and between birds and mammals.

Animals↗

PubMed1993

Electron microscopical observations of melanin in the endolymphatic sac.

Endolymphatic sacs of pigmented guinea pigs were examined by light and electron microscopy. Melanocytes were located not only in the subepithelial connective tissue but also in the intercellular spaces between the epithelial cells. They projected their dendrites into the epithelium extensively. Melanosomes in several stages of maturation and well-developed Golgi apparatus were seen in the cytoplasm of the melanocytes. Melanosomes were also observed in the membrane-bound vacuoles of the epithelial cells. These findings suggest that melanocytes in the endolymphatic sac are highly capable of producing tyrosinase, synthesizing melanin and transferring melanosomes to the epithelial cells, while melanocytes in the other parts of the inner ear do not show signs of melanogenesis under normal conditions.

Actin Cytoskeleton↗

PubMed1993

Pathological specimens of rat temporal bone--comparison between different fixative solution.

We investigated the difference in temporal bone specimens fixated by three sorts of fixative solution (10% formalin fixative, Wittmaack's fixative and Heidenhein-SuSa fixative). 1. 10% Formalin's fixative solution We found many pinkish precipitates, which are stained by hematoxy-eosin, in the scala media of the cochlea. Same substance is found in the perilymphatic space and endolymphatic space in the vestibulum. The fusion of the cells is indicated in the tectorial membrane, inner sulucus cell, outer sulucus cell especially in the apical turn of the cochlea. 2. Wittmaack's fixative solution The detachment of inner and outer sulucus cells are found from basilar membrane at the basal turn of the cochlea. The tendency in convex and concave form of the Reissner's membrane is most remarkable in these three fixative solution. 3. Heidenhein-SuSa fixative solution In this solution, no precipitates, no fusion of cells are found. No detachment of the inner or outer sulucus cells is also found. This study indicates that Heidenhein-SuSa fixation is most excellent fixative method.

Animals↗

PubMed1993

Immunological pathogenesis of endolymphatic hydrops and its relation to Menière's disease.

This study was designed to investigate an immunologically induced endolymphatic hydrops (ELH) and to focus on the issue of its pathogenesis in relation to Menière's disease. The time course of ELH was evaluated by light microscopy in a 2-hour to 7-month period following direct antigen challenge to the endolymphatic sac (ELS) in systemically pre-sensitized guinea pigs. ELH began to appear in the vestibule and the basal turn 5-7 hours after inner ear challenge and developed gradually. During the interval from the second day to the first week, ELH rapidly developed in all the cochlear turns and reached a maximum size. During the period from the second week to the eighth week, ELH gradually reduced. After 9 weeks, ELH of the saccule and the cochlea gradually recurred. During the interval from the first week to the eighth week, the time course of ELH correlated well with the grade of cellular infiltration of the perisaccular tissue. These results suggest that recurrent immunological reaction in the ELS may result in disorders of the ELS which finally lead to the onset of Menière's disease.

Animals↗

PubMed1992

Comparison of ascorbic acid and ascorbic acid 2-O-alpha-glucoside on the cytotoxicity and bioavailability to low density cultures of fibroblasts.

Ascorbic acid 2-O-alpha-glucoside (AA-2G) is a stable ascorbate derivative which has vitamin C activity in vivo and in vitro. We studied whether AA-2G exerts a prooxidant action in cultured fibroblasts from chick embryo and human skin, as does ascorbic acid. At concentrations of 0.1-1.0 mM, ascorbic acid markedly reduced the viable cell number of low density cultures within 24 hr, whereas AA-2G had no such effect. The ascorbate cytotoxicity was dependent on the cell density at the time of its addition and it was characteristic of low density cultures. This cytotoxicity was completely prevented by catalase and partially by an Fe3+ ion chelator, desferrioxamine. In the early culture stage at which a morphological change in the fibroblasts began to occur, intracellular ascorbate concentrations in low density cultures after addition of ascorbic acid were much higher than in high density cultures. However, at the same concentrations, AA-2G did not cause an elevation even in low density cultures and it was also effective on collagen synthesis at high and medium densities. These results suggest that the abnormally accumulated ascorbic acid in the cells cultured at low density possibly amplifies the generation of oxygen radicals through the reduction of Fe3+ ions and subsequent oxidative reactions, leading to cell death. Therefore, it is concluded that AA-2G which supplies an adequate amount of ascorbic acid during culture period is a bioavailable ascorbate source without cytotoxicity.

Animals↗