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Biomedical subjects

Y Majima

Publications and source records attributed to Y Majima.

At least 37 records · Page 2Linked to original sources
PubMed1999

Analysis of the Dielectric Relaxation Property of Phospholipid Monolayers by Maxwell Displacement Current Measurement.

Using the Maxwell displacement current (MDC) measurement with alternating monolayer compression and expansion process, the dielectric property of monolayers has been investigated. The monolayer expansion and compression processes were analyzed on the basis of the Debye theory, and the relaxation time of dl-alpha-dilaurylphosphatidylcholine (DLPC) was determined using a whole curve of MDCs. It was suggested that the interaction among molecules makes a contribution to the dielectric relaxation phenomena, although the change in the orientational order of polar molecules is a main contribution of MDC. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Effects of mucokinetic drugs on rheological properties of reconstituted human nasal mucus.

OBJECTIVE: To investigate the effects of mucokinetic drugs on the rheological properties of human nasal mucus in patients with chronic sinusitis. DESIGN: We reconstituted human nasal mucus obtained from 74 patients with chronic sinusitis and determined the effects of 4 mucokinetic drugs, including acetylcysteine, deoxynuclease I, 2% sodium bicarbonate, and a combination product containing tyloxapol (Alevaire), on rheological properties of reconstituted human nasal mucus (RHNM). We used 5% RHNM dissolved in phosphate-buffered solution as the optimal buffer and concentration of RHNM for the study because it showed a viscoelastic response similar to that of freshly collected nasal mucus from patients with chronic sinusitis. METHODS: Four experiments were performed to determine the influence of each drug on dynamic viscosity and elasticity of 5% RHNM. Distilled water was used as a control. RESULTS: Acetylcysteine and deoxynuclease I significantly decreased both dynamic viscosity and elastic modulus, while distilled water had no effect on rheological properties of 5% RHNM in vitro. Alevaire significantly reduced both dynamic viscosity and elastic modulus. Sodium bicarbonate significantly reduced elastic modulus but not dynamic viscosity. Reduction of elastic modulus by Alevaire was significantly greater than that by sodium bicarbonate, while there was no difference in reduction of dynamic viscosity between them. CONCLUSION: Our results indicate that RHNM may be useful for studying the topical effects of various drugs on nasal mucus from patients with chronic sinusitis.

Acetylcysteine↗
PubMed1999

Preventive effect of topical vitamin E-containing liposome instillation on the progression of galactose cataract. Comparison between 5-week- and 12-week-old rats fed a 25% galactose diet.

The preventive effect of topical vitamin E-containing liposome instillation on the progression of galactose cataract was compared between 5-week- and 12-week-old Wistar rats fed a 25% galactose diet. Vitamin E-containing liposomes [LP(+VE)] and vitamin E-free liposomes [LP(-VE)] were prepared with dipalmitoylphosphatidylcholine and dioleoylphosphatidylcholine (7:3 w/w). Twice daily instillation of either LP(-VE) or LP(-VE) into both eyes of 5-week-old rats fed the galactose diet for 18 days (5WGR) and 12-week-old rats fed the galactose diet for 7 weeks (12WGR) at which time some vacuoles appeared in the lens cortical equator, was conducted for a period of 4 and 9 weeks, respectively. The severity of cataracts at the end of instillation was similar in 5WGR and 12WGR. Instillation of LP(+VE), but not LP(-VE), retarded cataract progression in 5WGR and 12WGR. In 12WGR, LP(-VE) instillation caused a transient retardation of the progression. In lenses of 5WGR and 12WGR, decreases in vitamin E and reduced glutathione contents and increases in lipid peroxide, galactitol, and water contents occurred at the onset of instillation. For 5WGR, a decrease in lens reduced glutathione content and increases in lens vitamin E, lipid peroxide, galactitol, and water contents occurred at the end of instillation. For 12WGR, decreases in lens reduced glutathione and vitamin E contents and increases in lens lipid peroxide, galactitol, and water contents occurred at the end of instillation. In sera of 5WGR and 12WGR, vitamin E concentration decreased at the onset of instillation increased at the end in 5WGR and was unchanged in 12WGR. In 5WGR, instillation of LP(+VE), but not LP(-VE), for 4 weeks prevented these changes except the changes in lens galactitol and water contents and serum vitamin E concentration. In 12WGR, instillation of LP(+VE), but not LP(-VE), for 9 weeks prevented these changes except the changes in lens galactitol and water contents and serum vitamin E concentration. These results indicate that topically instilled LP(+VE) can retard cataract progression in 5WGR and 12WGR, mainly by the antioxidative action of vitamin E contained in the instilled liposomes.

Animals↗
PubMed1999

Analysis of HLA antigens in Japanese patients with chronic sinusitis.

OBJECTIVES: Genetic factors likely play a role in the etiology of chronic sinusitis and this disease is often associated with diffuse panbronchiolitis, which is strongly associated with HLA B54 antigen. The purpose of this study is to examine whether genetic factors are involved in the pathogenesis of chronic sinusitis. STUDY DESIGN: Eighty-two Japanese patients with intractable chronic sinusitis were selected on the basis of the following criteria: 1) persistent mucous or mucopurulent nasal discharge and/or postnasal dripping for longer than 3 years and 2) opacification in bilateral maxillary sinuses and ethmoid cells in plain X-ray films. METHODS: Both class I and class II HLA antigens were analyzed by conventional microcytotoxicity assays in these patients and 176 healthy control subjects. RESULTS: In class I antigens, B54 antigen significantly increased in the patient group (antigen frequency = 29.3%, relative risk = 3.23, corrected P value = .037) compared with normal control group (antigen frequency = 11.4%). For class II antigens, no antigens were significantly increased. CONCLUSION: These data indicate that certain genetic factors play a role in the etiology of chronic sinusitis.

Adolescent↗
PubMed1999

Cataract development in 12-month-old rats fed a 25% galactose diet and its relation to osmotic stress and oxidative damage.

We attempted to clarify the pattern of cataract development in 12-month-old rats fed a 25% galactose diet and to assess the relation of cataract development with osmotic stress and oxidative damage. In lenses of 12-month-old male Wistar rats fed a 25% galactose diet over an 8-month period, suture accentuation appeared at 6 months of galactose feeding and then opacities developed from the anterior subcapsular cortex toward the posterior subcapsular cortex, reaching the nuclear region at 8 months of galactose feeding. Increases in lens galactitol and lipid peroxide contents and a decrease in lens reduced glutathione content occurred at 4, 6 and 8 months of galactose feeding. The increase in lens lipid peroxide content and the decrease in lens reduced glutathione content were accelerated with an increase in feeding period, while the increase in lens galactitol content was decelerated. An increase in lens water content and a decrease in lens protein content occurred at 6 and 8 months of galactose feeding. The lens vitamin E content increased at 6 months of galactose feeding and this increase was concomitant with increases in serum vitamin E and total cholesterol concentrations. The serum lipid peroxide concentration increased at 4 and 6 months of galactose feeding. The present results indicate that in lenses of 12-month-old rats fed a 25% galactose diet, suture accentuation appears initially and then opacities develop from the anterior subcapsular cortex toward the posterior subcapsular cortex, finally reaching the nuclear region. These results also suggest that in the galactosemic aged rats, osmotic stress would mainly contribute to cataract formation, while oxidative damage could be linked to both cataract formation and progression, although an increase in lens vitamin E content occurs during the cataract development.

Animals↗
PubMed1999

Effect of biochemical components on rheologic properties of nasal mucus in chronic sinusitis.

The effect of biochemical components on the viscoelasticity of nasal mucus from 24 patients with chronic sinusitis (CS) was investigated by multiple stepwise regression analysis. The dynamic viscosity (eta') and the elastic modulus (G') of nasal mucus were determined with an oscillating sphere magnetic rheometer at oscillatory frequencies of 1 and 10 Hz. The eta' and G' values of mucus determined at 1 Hz were 1.6 +/- 1.5 Pa/s and 31.8 +/- 31.0 Pa, respectively, and these values were much higher than optimal viscoelasticity for mucociliary transport. The concentrations of fucose, N-acetyl neuraminic acid, albumin, IgG, secretory-IgA, and lysozyme were measured in the same mucus samples. The multiple regression analysis showed that the concentration of fucose, a marker of mucous glycoproteins, was the most important determinant of eta' and G'. The analysis also revealed that the level of IgG was the next important determinant. The coefficients of multiple determination for fucose and IgG were 0.732 and 0.733 when the response variables were eta' and G', respectively. The results indicate that locally produced mucous glycoproteins may largely contribute to the high viscoelasticity of nasal mucus in CS.

Adolescent↗
PubMed1999

[Primary ciliary dyskinesia].

Primary ciliary dyskinesia (PCD) is a congenital disorder of cilia mostly associated with ultrastructural defects and resulting in immotility or abnormal motility, with or without a situs inversus. The defects of cilia in PCD cause chronic or recurrent upper and lower respiratory diseases, such as chronic bronchitis, bronchiectasis, chronic sinusitis and otitis media with effusion. Transmission electron microscopy of sperm or respiratory ciliated mucosa allows specific anatomic diagnosis of PCD. Treatment is symptomatic and directed against complications in the respiratory tract. Early physiotherapy is recommended.

Chronic Disease↗
PubMed1998

A comparative study of the ciliary area of the maxillary sinus mucosa and computed tomographic images.

The ciliary area of the maxillary sinus mucosa and coronal sinus computed tomographic (CT) scans were studied in 36 maxillary sinuses of 28 patients with chronic sinusitis. Tissue specimens allowed ciliary surfaces to be observed under scanning electron microscopy, allowing surfaces to be expressed in terms of ciliary area (CA) as the percentage of mucosal surface occupied by cilia. The opacity produced by mucosal swelling and secretion in the maxillary sinus on CT was assessed by two methods: Min's and modified van der Veken's methods. Both techniques indicated an inverse correlation between opacity of the maxillary sinus and CA. Our findings suggest that the opacity of maxillary sinus on CT could be a significant parameter for predicting the surface conditions of ciliated maxillary mucosa prior to sinus surgery.

Adult↗
PubMed1998

Gammadelta T cell receptor repertoire in middle ear effusions in children.

In order to elucidate the immune response in otitis media with effusion, polymerase chain reaction was employed to examine gammadelta T cell receptor repertoire in the middle ear effusions of patients with otitis media with effusion. RNAs were extracted from 13 middle ear effusions of 10 children with otitis media with effusion. Vgamma2 was the most frequently used Vgamma gene. As for Vdelta gene usage, Vdelta2 amplification gave the strongest signal in 10 out of 13 samples. The results suggest that gammadelta T cells bearing Vgamma2/Vdelta2 T cell receptors accumulate in the middle ear effusions in children, and that these T cells may respond to certain bacteria or bacterial products in the middle ear.

Adolescent↗
PubMed1998

Quantitative cytology of nasal secretions with perennial allergic rhinitis in children: comparison of noninfected and infected conditions.

This study was performed to quantify the number of inflammatory cells in nasal secretions from pediatric patients with perennial allergic rhinitis under noninfected and infected conditions. Nasal secretions were obtained from seven children under both noninfected and infected conditions with perennial allergic rhinitis to house dust mites, and secondary quantitative cytology was performed on the secretions. The number of neutrophils under infected condition was significantly higher than that under noninfected condition (P < .05), whereas the number of eosinophils in infected condition was significantly lower than that in noninfected condition (P < .05). The ratio of eosinophil count to neutrophil count was more than 0.1 in noninfected condition. The ratio was significantly decreased in infected condition (P < .02). These results suggest that the distribution of inflammatory cells in the nasal mucus of children with allergic rhinitis would be modified under infected condition.

Adolescent↗
PubMed1998

Cell-biological analysis of atopic cataractous lenses.

The number of people suffering from atopic dermatitis, a recent social problem believed to have arisen from environmental pollution and changes, continues to increase today, and these patients often encounter complications such as cataract and retinal detachment. In this study, I have conducted (1) a comparative study on the rate of cell proliferation between lens epithelial cells (LECs) obtained from 7 atopic cataractous lenses and from 1 normal lens, (2) a comparative study on cell density and alignment between LECs obtained from 5 nonatopic cataractous lenses and from 5 atopic cataractous lenses and (3) transmission electron microscopy of LECs obtained from 3 atopic cataractous lenses. My findings were as follows: (1) except for 1 case disclosing increased proliferative activity of the cells to become multilayered, LECs of atopic cataractous lenses showed diminished proliferative activity; (2) LECs of atopic cataractous lenses had decreased in cell density and revealed irregular cell alignment; (3) transmission electron microscopy of LECs of atopic cataractous lenses demonstrated multilayered cells, increased intercellular spaces, and degeneration and disappearance of some cells. A longer follow-up period and further studies using cells from additional atopic cataractous lenses are necessary before any conclusions can be drawn. However, obtaining human LECs especially of atopic cataract patients is not easy, and I do feel that my present study, although its number of patients may not be large enough, provides significant findings for further studies on the mechanism of atopic cataract formation.

Adolescent↗
PubMed1998

Nasal mucociliary clearance of chronic sinusitis in relation to rheological properties of nasal mucus.

The role of the viscosity (eta') and elasticity (G') of nasal mucus in nasal mucociliary clearance (MCC) in chronic sinusitis (CS) was studied. The nasal mucus was collected from 17 patients with CS, and both eta' and G' were determined by an oscillating sphere magnetic rheometer. Following the nasal mucus collection, nasal MCC was measured by a radioisotope method in the patients and 22 normal subjects. Nasal MCC in the patients was significantly reduced compared with that in the normal subjects (p < .05). No significant correlation was noted between nasal MCC and eta', or between nasal MCC and G'. The results suggest that factors other than eta' and G' of nasal mucus may control nasal MCC in CS.

Adult↗