Biomedical subjects

M Ohyama

Publications and source records attributed to M Ohyama.

At least 91 records · Page 5Linked to original sources

PubMed1995

Allergic rhinitis in laboratory workers caused by occupational exposure to guinea pigs: an immunological and clinical study.

Occupational exposure in laboratory workers to various animals can result in clinically significant respiratory allergies. We used clinical and immunological methods to study five laboratory workers who exhibited symptoms of nasal allergy upon occupational exposure to guinea pigs. As compared with a control group of ten nonallergic laboratory workers, the symptomatic workers generally had positive skin test reactions for allergens derived from the urine, saliva, and pelts of the guinea pigs. The study group with symptoms also showed high serum levels of specific IgE and demonstrated an immediate, positive reaction to nasal provocation testing with urine-derived antigen. However, specific IgG values in the sera of these patients did not differ significantly from control values. Overall results indicated that a type 1 allergy was involved.

Adult↗

PubMed1995

Effects of oxygen radicals on ciliary motility in cultured human respiratory epithelial cells.

There are few reports about direct effects of specific oxygen products on ciliary function because of their instability and reactivity. We investigated the direct effects of superoxide anion (O2-) and of hydrogen peroxide (H2O2) on the ciliary function of human respiratory epithelial cells, using monolayer cell cultures, high speed video analysis of frequency (CBF), amplitude (CBA), and coordination of ciliary beats and evaluating the surface structural changes of ciliated cells at the same time. 10(-2) M H2O2 decreased ciliary beat activity. The CBF was 36.5 +/- 4.4% and the CBA was 51.0 +/- 3.8% of the baseline (time = 0) after 5 min (all p < 0.001). Catalase (2 micrograms/ml) abolished the ciliotoxic effect of H2O2. The O2- produced by reaction of xanthine (0.06 mM)-xanthine oxidase (0.04 U/ml) caused a temporary rapid increase of 26.8 +/- 1.7% in CBF and an increase of 42.5 +/- 4.1% in CBA after 15 sec (all p < 0.001). Superoxide dismutase significantly reduced these increases. Results indicated that O2- activated ciliary function with a temporary increase in O2(-)-production. This suggests that the removal of H2O2 from the O2- reaction is important in improving mucociliary clearance in excessive oxygen metabolites.

Cells, Cultured↗

PubMed1995

Unusual case of myoepithelioma associated with adenoid cystic carcinoma of the parotid gland.

Tumors of the salivary glands comprise less than 3% of all neoplasms of the head and neck, with synchronous parotid tumors of differing histologic types being extremely rare. We present a 71-year-old woman with a myoepithelioma associated with an adenoid cystic carcinoma of the left parotid gland. The 48 previously reported cases of synchronous occurring parotid gland tumors of differing histologic types are reviewed.

Aged↗

PubMed1995

Antibacterial activity of flavanostilbenes against methicillin-resistant Staphylococcus aureus.

Three phytochemical compounds (alopecurone A-C), flavanostilbenes which are produced by condensation between a hydroxyflavanone and a hydroxystilbene, were isolated as major components from the root of Sophora alopecuroides. They uniformly inhibited the growth of 21 strains of methicillin-resistant Staphylococcus aureus with minimum inhibitory concentrations of 3.13-6.25 micrograms ml-1.

Anti-Bacterial Agents↗

PubMed1995

[Immunohistochemical study on temporal bone of autopsy cases with Mycobacterium leprae infection].

Three temporal bones were obtained en bloc from autopsy cases with lepromatous leprosy from the middle cranial fossa side after removing the brain. After fixation with 10% formalin followed by sufficient decalcification, the specimens were embedded in paraffin en bloc and cut serially to stain every 10th section with hematoxylin and eosin (H&E) for anatomical orientation. An immunohistochemical study with anti-neurofilament, anti-MBP (myelin basic protein), anti-BCG (Bacillus Calmette-Gue'rin) and anti-PGL (Mycobacterium leprae-specific antiphenolic glycolipid-I) antibodies were performed to vestibular, cochlear and facial nerves, respectively, on the basis of anatomical orientation of the adjacent H&E sections. In one of three cases, positive staining by anti-PGL antibodies was recognized only in the facial nerve both in its internal auditory meatal and tympanic portions. However, even in this case, no neural damage was observed either by anti-neurofilament nor anti-MBP stainings. This finding supports the possibility of central neural infection by Mycobacterium leprae.

Aged↗

PubMed1995

Effects of (-)-S-2,8-dimethyl-3-methylene-1-oxa-8-azaspiro[4,5]decane L-tartrate monohydrate (YM796), a novel muscarinic agonist, on disturbance of passive avoidance learning behavior in drug-treated and senescence-accelerated mice.

Effects of YM796 (-)-S-2,8-dimethyl-3-methylene-1-oxa-8-azaspiro[4,5]decane L-tartrate monohydrate; a novel muscarinic agonist, were observed on disturbance of passive avoidance learning behavior in drug- (protein synthesis inhibitor and anticholinergic drugs) treated and senescence-accelerated mice in comparison with those of a muscarinic agonist (AF102B) and acetylcholinesterase inhibitors (E2020 (1-benzyl-4-[(5,6-dimethoxy-1-indanone-2-yl) methyl] piperidene hydrochloride), NIK247 [9-amino-2,3,5,6,7,8-hexahydro-1H-cyclopenta(b)-quinoline monohydrate hydrochloride], THA (9-amino-1,2,3,4-tetrahydroacridine) and physostigmine). All tested drugs administered before training significantly prolonged the shortened latency of step-through induced by the protein synthesis inhibitor cycloheximide (150 mg/kg s.c.). This shortened latency was also significantly prolonged when YM796 was administered immediately after training, but not when administered before the test trial. The ameliorating effect of YM796 on the impairment in learning behavior by cycloheximide was significantly suppressed by pirenzepine (0.1 micrograms/mouse i.c.v.). When administered before training, all test drugs prolonged the shortened latency of step-through induced by treatment with the anticholinergic drugs [scopolamine (1 mg/kg s.c.) and hemicholinium-3 (0.3 microgram/mouse i.c.v.)], suggesting that they ameliorated the impairment of learning behavior. This shortened latency in scopolamine-treated mice was also significantly prolonged by YM796, AF102B, E2020, NIK247 and physostigmine when administered immediately after training, but not when administered before the test trial. The pharmacological actions of YM796 administered immediately after training and before the test trial in hemicholinium-3-treated mice were similar to those in scopolamine-treated mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1995

[Changes in regional cerebral blood flow in nondominant hemisphere during speech task in aphasics.: a PET activation study].

To investigate the patients with language disorder and to detect the activated areas in language processing, we measured the changes in the regional cerebral blood flow (CBF) during speech task (¿counting¿ task) using O-15 water PET activation technique in six normal subjects (age 58.3 +/- 8.1), mean +/- SD), ten fluent aphasics (age 60.3 +/- 12.5) and six nonfluent aphasics (age 50.5 +/- 8.3). In ¿counting¿ task, the subjects were instructed to count the number aloud from 1 to 10 and repeat the sequence over and over in the native language (Japanese) at the rate of one number per 2.5 sec. The data were analyzed with stereotactic intersubject averaging analysis for the normal subjects. Apart from it, the regions of interest (ROI) analysis (a circular ROI of 12 mm diameter) was performed in the language-related areas: posteroinferofrontal areas (PIF), posterosuperotemporal area (PST), and Rolandic areas (related to the mouth and lips) were significantly activated bilaterally in the ¿counting¿ task. PIF were activated with a dominance in the left side. In the resting state, rCBF in the left PIF and left PST were activated with a dominance in the left side. In the resting state, rCBF in the left PIF and left PST was reduced in both fluent and nonfluent aphasics. In nonfluent aphasics, the magnitude of activation in the right PIF by ¿counting¿ task was significantly greater than normal subjects and patients with fluent aphasia (ANOVA). It suggests the importance of the right PIF in the simple language processing in the nonfluent aphasia. In the sixteen aphasic patients, the increase in rCBF in the right PST during the ¿counting¿ task was negatively correlated with the score of comprehension (WAB) in the Spearman ranked correlation (p < 0.05). It suggests that, while the activity of the right PST is minimal for the ¿counting¿ in normal subjects, it plays an important and compensatory role in aphasic patients.

Adult↗

PubMed1995

[Regional cerebral glucose metabolism associated with ataxic gait--an FDG-PET activation study in patients with olivopontocerebellar atrophy].

We studied changes in regional cerebral glucose metabolism during bipedal gait in 7 patients with olivopontocerebellar atrophy (OPCA) and 7 control subjects without neurological disease. All OPCA patients in this study were able to walk on the treadmill without a support or handrails. We used 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) and positron emission tomography (PET) to evaluate glucose metabolism under two different conditions; 30 minutes' treadmill walking, and supine resting. The two sets of PET images were three-dimensionally registered to the magnetic resonance image (MRI) in each subject. Then, the PET images were normalized by the global value. Regions of interest (ROIs) were drawn on the cerebellar vermis, cerebellar hemispheres, pons, and thalamus, and FDG uptake was obtained to calculate the activation ratio (= [FDG uptake under walking]/[FDG uptake under resting]) for each region. We used unpaired t-test for statistical analysis to compare the OPCA patients and the normal control subjects. Normalized resting FDG uptake had no significant difference between control subjects and OPCA patients in any region. Activation ratio of OPCA patients was significantly decreased in the cerebellar vermis compared with the control subjects. In the control subjects, FDG uptake had little difference between resting and walking in the cerebellar hemisphere, pons and thalamus. On the other hand, the FDG uptake of OPCA patients was moderately increased by walking in these regions. In the cerebellar vermis, in spite of no significant difference between the normals and the patients during resting, the activation ratio in OPCA patients was significantly decreased. We speculate that the reduction of activation ratio in the cerebellar vermis reflects the dysfunction caused by degeneration. The result suggests that the PET activation study can demonstrate cerebellar dysfunction in the early phase of OPCA, in which other neuro-imaging methods cannot detect the tissue atrophy, hypometabolism or hypoperfusion in the resting state. In the cerebellar hemisphere, pons and thalamus, the activation ratio was nearly equal to one in control subjects, while it was larger in OPCA patients. We speculate that the instability during the ataxic gait increases the inputs from the vestibular, somatosensory and visual systems to these regions and outputs from these regions to the other neural systems. In conclusion, PET activation study is a useful and noninvasive technique for investigating the brain function associated with human gait.

Adult↗

PubMed1994

Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones.

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml.

Actinomyces↗

PubMed1994

Diurnal variation of hue discriminatory capability under artificial constant illumination.

Diurnal variation of hue discriminatory capability under artificial constant illumination of 4000 lux was studied with 10 young female adults using the 100-hue test. There were conspicuous diurnal variations in the yellow-blue and red-green systems, with marked reductions of error score in the evening. However, observations of the blue, yellow, green and red systems separately disclosed that there existed clear diurnal rhythms in the blue and green systems, but not in the yellow and red systems. This suggests the existence of diurnal variation in function of the S and M cones responsible for the blue and green hue.

Adult↗

PubMed1994

Differences in terminal carbohydrate structures of sialomucin in the murine nasal cavity.

Terminal carbohydrate structures of sialomucin in the murine nasal cavity were characterized by means of lectin histochemistry. Two kinds of biotinylated lectins (Maackia amurensis agglutinin and Sambucus nigra agglutinin), which recognize sialic acid residues, showed marked differences in their respective labeling patterns when used as epithelial probes. Maackia amurensis agglutinin labeled the epithelial goblet cells, Bowman's glands, and all cell surfaces of both olfactory and respiratory epithelium. In contrast, Sambucus nigra agglutinin labeled cell surfaces and Bowman's glands in the murine olfactory epithelium, but did not label the murine respiratory epithelium. These results indicate that sialomucin in the murine nasal cavity has two different terminal carbohydrate structures. Our data show that sialomucin in the murine respiratory epithelium has a Neu5Ac(alpha 2-3)Gal sequence, while sialomucin in the murine olfactory epithelium has both alpha 2-3 and alpha 2-6 binding sequences. These results suggest that different carbohydrate structures of sialomucin in the nasal cavity may reflect differences in susceptibility to bacterial colonization and viral infection between respiratory and olfactory epithelium, and influence rheological properties of nasal secretion.

Animals↗

PubMed1994

Possible involvement of central cholinergic system in ameliorating effects of indeloxazine, a cerebral activator, on disturbance of learning behavior in rats.

Effects of indeloxazine, a cerebral activator, on passive avoidance learning by disruption of cholinergic transmission were studied in rats. The shortened latency was prolonged when indeloxazine was administered before training in rats subjected to scopolamine-injection, ethylcholine aziridinium ion (AF64A)-treatment and nucleus basalis magnocellularis (NBM) lesion. Indeloxazine administered immediately after training also showed ameliorating effects on passive avoidance in NBM-lesioned rats. Indeloxazine increased extracellular acetylcholine concentration in the frontal cortex of rats. Indeloxazine possesses facilitatory effects on cerebral function in part due to activation of the central cholinergic system.

Acetylcholine↗

PubMed1994

Flavanones with potent antibacterial activity against methicillin-resistant Staphylococcus aureus.

With the therapeutic concept of using the defensive ability of plants against microbial infections, phytoalexin, an antimicrobial phytochemical was studied for its ability to inhibit the growth of methicillin-resistant Staphylococcus aureus (MRSA). Extracts from Sophora exigua (Leguminosae) were fractionated by serial chromatography and the anti-MRSA activity of each fraction was determined by the agar-plate method. Among the active isolates, 5,7,2',6'-tetrahydroxy-6-isoprenyl-8-lavandulyl-4'-methox yflavanone (exiguaflavanone D) completely inhibited the growth of all the MRSA strains examined at the concentration of 1.56-6.25 micrograms mL-1, and 5, 2',6'-trihydroxy-8-lavandulyl-7-methoxy-flavanone (exiguaflavanone B) inhibited at a concentration of 50 micrograms mL-1. This former compound is expected to be a phytotherapeutic agent for MRSA infections as an alternative to conventional antibiotics with unwanted side-effects or the appearance of antibiotic-resistant bacteria.

Anti-Bacterial Agents↗

PubMed1994

Ciliogenesis and mucus synthesis in cultured human respiratory epithelial cells.

The mechanisms for the regulation of ciliogenesis and for the synthesis of mucus are not well understood. We sought to develop a culture system for differentiating ciliated and secretory types of human respiratory epithelial (HRE) cells. Dissociated HRE cells obtained from nasal polyps and maxillary sinus mucosa were cultured on type I collagen gel. Cells grown to confluence on collagen gel lost their cilia and exhibited a flat, squamous-like appearance. After reaching confluence, the cultured cells with a collagen gel substrate were removed from plastic dishes and floated in the culture medium. After 7 days in the floating culture, some cells exhibited several centrioles or basal bodies, while others showed secretory granules. The secretory phenotype predominated after 7 days. After 14 days in the floating culture, nearly all cells were ciliated. The results demonstrate that the differentiation of HRE cells can be induced by floating cultured cells with a collagen gel substrate in a defined culture medium.

Cell Differentiation↗

PubMed1994

Laser beam in treating congenital choanal atresia in three patients.

We present the results of 3 patients with congenital unilateral choanal atresia who were treated surgically at our department. We report a method of surgical approach for repair of choanal atresia. A transpalatal procedure offers an approach which is straightforward. The use of carbon dioxide or Nd:YAG laser seemed better for recurrent cases. A tube stent should be placed for at least 6 weeks postoperatively.

Adolescent↗

PubMed1994

Presence of neuropeptides in human nasal polyps.

The pathophysiological effects of non-cholinergic, non-adrenergic neuropeptides are well known in the nasal mucosa, but unclear in the polyps. Since the pathophysiological roles of neuropeptides depend on their presence in the target tissue, specimens of nasal polyps were removed from 20 patients and examined for the presence of vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), dopamine-beta-hydroxylase (DBH), substance P (SP) and calcitonin gene-related peptide (CGRP). To visualize these neuropeptide fibers, immunohistochemical staining by the peroxidase-anti-peroxidase method and color reaction by Nickel enhancement of diaminobenzidine (DAB) were used. Fine varicose neuropeptides immunostained fibers were predominantly distributed in the pedicle of the polyps. No neuropeptides were found in the mucosal epithelium and subepithelium. NPY fibers were predominantly seen around the thick wall vessels, whereas the VIP fibers were mainly to be found in close proximity to the submucosal glands and fairly close to the vessels. SP or CGRP fibers were not found in the polyps. VIP and NPY in the pedicle of the polyps may be present in connection with mucosal inflammation, tissue edema and cystic degeneration of the glands in the early stage of polyp formation. Thus these neuropeptides may contribute to the development and growth of nasal polyps.

Calcitonin Gene-Related Peptide↗

PubMed1994

Effect of exogenous ATP and physical stimulation on ciliary function impaired by bacterial endotoxin.

The effects of exogenous ATP and physical stimulation on ciliary beat depressed by lipopolysaccharide from Pseudomonas aeruginosa were studied in cell culture. Both the ciliary beat frequency (CBF) and the amplitude (CBA) of human respiratory cells in monolayer cell cultures were studied by using a differential interference microscope equipped with a high speed video. Both the ATP and the physiol stimulation stimulated temporarily the depressed CBF and CBA. In both groups the CBF and CBA increased in 1 min to the initial level and then gradually decreased to the level before the stimulation. The duration of the ATP stimulation on the CBF (10.1 +/- 1.8 min) and CBA (10.1 +/- 2.3 min) were significantly better than the duration of physical stimulation on CBF (8.0 +/- 1.8 min) and CBA (6.8 +/- 1.6 min). However, the areas under the CBF/CBA curves (from the beginning of stimulation until the initial level of CBF or CBA was reached again) did not differ significantly. After the removal of the bacterial toxin the CBF was restored to the initial level. In the present study the adenosine receptor antagonist could not prevent the ciliostimulative effect of exogenous ATP combined with the physical stimulation. Both exogenous ATP and physical stimulation have a clear but temporary stimulative effect on the ciliary beat depressed by bacterial toxin, ATP being slightly more effective. It seems that the effects of ATP are not mediated by adenosine receptors.

Adenosine Triphosphate↗

PubMed1994

[The activity of superoxide dismutase in patients with taste and smell dysfunction].

It was revealed that Zinc deficiency might cause taste and smell dysfunction. Superoxide dismutase (SOD), which scavenges superoxide, is a type of zinc enzyme. It was also demonstrated that the overproduction of superoxide damages normal tissue. We therefore measured the activity of SOD in serum and saliva of patients with taste or smell dysfunction by the cytochrome C reduction method using a xanthine-xanthine oxidase system. As a result, in the patients with taste dysfunction, the activities of SOD in both serum and saliva were normal, but mean level of serum Zinc was near to the lower normal limit. On the other hand, in the patients with smell dysfunction caused by chronic sinusitis or common cold, the activity of SOD in serum was significantly lower than that of healthy volunteers, and that in saliva was normal. These results suggest that Zinc enzymes, except serum and salivary SOD, are involved in the sense of taste, and that further investigation is necessary to clarify the relation between serum SOD deficiency and olfactory dysfunction.

Adult↗