Biomedical subjects

M Ohyama

Publications and source records attributed to M Ohyama.

At least 73 records · Page 4Linked to original sources

PubMed1997

[Neurogenous tumors in head and neck region].

We treated 26 patients with neurogenous tumors in the head and neck region in our hospital during the past 17 years. Their pathologic diagnoses were neurilenoma in 25 cases and paraganglioma in 1 case. The origin of the tumor was vagus in 4 cases, hypoglossal nerve in 3 cases, and sympathetic nerve in 3 cases. Neurological defect symptoms were observed in 12 cases after the surgery. The most common symptom was recurrent nerve palsy. The characteristic finding in the imaging study and the frequency of postoperative neurological disturbance were discussed.

Adolescent↗

PubMed1997

Assessment of cell surface glycoconjugates in normal, benign and malignant human nasal mucosa.

Aberrant glycosylation of proteins is a common characteristic of neoplastic changes. No reports exist relating cell surface glycoconjugates to normal, benign and malignant human nasal mucosa. Using lectin affinity histochemistry, glycoconjugate reactivities for peanut agglutinin (PNA), concanavalin A (Con A), Griffonia simplicifolia agglutinin II (GSA-II), soy bean agglutinin (SBA) and Ulex europaeus agglutinin l (UEA-I) were analysed in the following groups: normal, benign (polyp, papilloma, and inverted papilloma) and malignant (squamous cell carcinoma (SCC) alone, SCC arising in inverted papilloma, and adenocarcinoma). The positive rate of lectin staining was evaluated using a quantitative AutoCAD programme. We correlated glycoconjugate expression to clinical features, diagnosis, and malignant transformation. The positive rate of PNA after neuraminidase pre-treatment (NA-PNA) staining was higher in inverted papilloma, while all-negative in polyp and papilloma. NA-PNA staining may be used as a differential diagnostic tool. Both inverted papilloma portions and SCC portions of the SCC synchronized with inverted papilloma subjects showed similar Con A and NA-PNA staining patterns. The biological characteristics define inverted papilloma as a pre-malignant neoplasm. The positive rate of PNA staining was significantly higher in inverted papilloma (inverted papilloma transformed to SCC) compared to inverted papilloma alone. Hence, PNA staining may predict malignant transformation of inverted papilloma. However, further investigations are required to prove this possibly worthwhile prognostic marker.

Adenocarcinoma↗

PubMed1997

A rare case of nasal schwannoma with intracranial extension.

A rare case--only the fourth as known--of a nasal schwannoma with intracranial extension is presented. A 28-year-old Japanese man complained of right nasal obstruction and bleeding for one year. A biopsy indicated the presence of a nasal schwannoma. Computed tomography and magnetic resonance imaging demonstrated intracranial extension of the tumour. The patient underwent surgery with a combined intra- and extracranial approach. Reconstruction was performed using pericranial flaps. Surgical management of this tumour is also described.

Adult↗

PubMed1996

Umbilical cord ulceration and intestinal atresia.

Umbilical ulceration is an extremely rare complication in the perinatal period. We encountered a case of intestinal atresia complicated by massive intrauterine hemorrhage due to the umbilical cord ulceration. This is the fifth reported case demonstrating an association between the umbilical cord ulceration and intestinal atresia.

Adult↗

PubMed1996

Histological changes in elastic components of soft palate scars after CO2 and contact Nd:YAG laser incisions in the dog as an experimental model.

Soft palate stiffening operations--often with CO2 or contact Nd:YAG lasers--have been used recently to treat patients with pronounced snoring. Differences in soft palate scars formed after CO2 and contact Nd:YAG laser incisions were studied in an animal model to determine which of these lasers produces a more rigid scar and consequently might be more effective for a soft palate stiffening operation. Six mongrel dogs were placed in each laser group, after which either the CO2 or Nd:YAG laser was used to make a 1.5-cm-long soft palate incision. The scars produced were then excised and studied histologically 4 weeks postoperatively. Special attention was paid to collagen density and elastin fibers in the scar tissue. After contact Nd:YAG laser incisions scar tissue was found to contain densely aligned collagen fibers and practically no elastin fibers. CO2 laser incisions produced significantly different scars: irregularly arranged collagen fibers with some elastin fibers also inside the scar tissue. Differences in the shapes of the scars and wound contractions were also found that were only seen after contact laser incisions. These findings suggest that the contact Nd:YAG laser might be more effective for soft palate stiffening operations.

Animals↗

PubMed1996

Functional neuroanatomy of visual object naming: a PET study.

BACKGROUND: The ability to name objects depends partly on visual perception. We used positron emission tomography (PET) to measure activity-related changes in regional cerebral blood flow (r-CBF) in order to identify regions of the brain activated during visual object naming. METHODS: Four right-handed volunteers were recruited. Following an intravenous injection of 15O-labeled water, r-CBF was measured during visual object naming, counting numbers, and resting. PET and MRI images were coregistered, the size of the brain was proportionally adjusted in each axis to Talairach's and Tournoux's atlas, and the comparison of stimulated versus resting blood flow images revealed activated brain regions. RESULTS: In the subtraction of resting from naming, activation was observed in the bilateral primary visual cortex, bilateral fusiform gyrus, left lingual gyrus, bilateral inferotemporal cortex, bilateral inferior frontal gyrus, bilateral precentral gyrus, anterior cingulate gyrus, left parietal operculum, and left putamen. In the subtraction of counting from naming, most of the those areas were activated, but no significant activity was observed in the left lingual gyrus, left parietal operculum, or bilateral precentral gyrus (motor cortex). The areas activated with the paradigm included those dedicated to visual perception (primary and associate visual cortex), visual recognition (inferior temporal cortex), and phonological output (Broca's area). CONCLUSION: Our results indicated that the major neural network from occipital lobe to frontal cortex, which is mainly involved in the ventral visual pathway, demonstrated activation in these tasks. Result of this study will serve as base line data for analyzing the findings in patients with impaired visual perception.

Adult↗

PubMed1996

Comparative study on the antibacterial activity of phytochemical flavanones against methicillin-resistant Staphylococcus aureus.

Differently substituted flavanones were isolated from Leguminosae and their antibacterial activity was comparatively studied against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MICs) of phytochemical flavanones to clinical isolates of MRSA were determined by a serial agar dilution method. The structure-activity relationship has indicated that 2',4'- or 2',6'-dihydroxylation of the B ring and 5,7-dihydroxylation of the A ring in the flavanone structure are important for significant anti-MRSA activity and that substitution with a certain aliphatic group at the 6- or 8-position also enhances the activity. Among the thirteen flavanones tested, tetrahydroxyflavanones with these structural characteristics isolated from Sophora exigua and Echinosophora koreensis showed intensive activity to inhibit the growth of all MRSA strains at 3.13-6.25 micrograms/ml. The present hydroxyflavanones would be useful in the phytotherapeutic strategy against MRSA infections.

Anti-Bacterial Agents↗

PubMed1996

Surgical reconstruction of the ocular surface in advanced ocular cicatricial pemphigoid and Stevens-Johnson syndrome.

PURPOSE: Ocular cicatricial pemphigoid and Stevens-Johnson syndrome often cause ocular damage and blindness not amenable to surgical correction. We present a new surgical technique for reconstructing affected eyes. METHODS: Fourteen eyes of 11 patients with cicatricial keratoconjunctivitis (seven patients with cicatricial pemphigoid and four with Stevens-Johnson syndrome; average age +/- S.D., 55.5 +/- 25.4 years) were treated with a combination of allograft limbal transplantation, amniotic membrane transplantation, and tarsorrhaphy, followed every 15 minutes by artificial tears derived from the patient's blood serum. Eight eyes required concomitant penetrating or lamellar keratoplasty because of corneal opacity. RESULTS: With a mean follow-up of 143 days (range, 10 to 608 days), we achieved successful ocular surface reconstruction in 12 eyes, with minimal recurrence of symblepharon. Failure occurred in two eyes (one each in 9- and 10-year-old boys) that developed corneal infiltration and vascularization. CONCLUSIONS: A combination of allograft limbal transplantation, amniotic membrane transplantation, and tarsorrhaphy, followed by the use of serum-derived tears, can reconstruct the ocular surface in most cases. Although in this study the follow-up period was short and relatively few patients were studied, this approach appears to offer an alternative to keratoprosthesis for treating severe cicatricial keratoconjunctivitis with dry eye.

Adult↗

PubMed1996

Relationship between abnormal sensation in the throat and menopause.

Abnormal sensations in the throat (AST) are commonly encountered in general and otolaryngological practice, especially among middle aged women. These sensation may occur alone, or more often, in combination with the systemic symptoms, including those of menopause. We analyzed 26 Japanese women with a complaint of an abnormal sensation in the throat who were taking a synthetic sex hormone (Methermon-F). Multianalysis of variance (MANOVA) was used to evaluate the efficacy of the treatment using the quantitative scores of Kupperman's climacteric symptoms. The presence of the excessive perspiration and vertigo, insomnia, and the absence of fatigue were associated with clinical efficacy of the hormone, while the presence of hyposthenia and tingling sensation were associated with a poor response. Results suggested that the clinical efficacy of this hormone in treating middle-aged menopausal women with AST was related to the menopausal symptoms.

Adult↗

PubMed1996

Case of ageusia from a variety of causes.

We report a case of a 31-year-old woman with ageusia. Her ageusia was related to a variety of causes including an unbalanced diet, administration of the anti-epileptic drug, carbamazepine and psychological factors. Her taste function recovered after stopping the carbamazepine and treatment with liver extracts and zinc sulphate.

Adult↗

PubMed1996

Laser-assisted uvulopalatoplasty with Nd:YAG laser for sleep disorders.

We evaluated the apnea index (AI), the oxygen saturation above 95% (SA95), the lowest oxygen saturation (LSAT), and snoring before and after laser-assisted uvulopalatoplasty (LAUP) in 106 patients with obstructive sleep apnea syndrome (n=59) or snoring (n=47). Type 1 LAUP was performed in 42 patients and type 2 LAUP in 64 patients. A 50% or greater reduction in AI was observed in 15 patients (35.7%) who underwent type 1 LAUP and 37 patients (57.8%) who underwent type 2 LAUP. Snoring was diminished in 18 (51.4%) of 35 patients who underwent type 1 LAUP and 30 (55.6%) of 54 patients who underwent type 2 LAUP. SA95 and LSAT showed no difference. No serious complications such as significant bleeding, postoperative episodes of asphyxia, nasopharyngeal stenosis, or nasal regurgitation were observed. LAUP was an effective outpatient treatment.

Adult↗

PubMed1996

Th1/Th2 response profiles to the major allergens Cry j 1 and Cry j 2 of Japanese cedar pollen.

Cry j 1 and Cry j 2 are known to be the major allergens of Japanese cedar pollen. A comparative study was carried out on the immune responses to stimulation with Cry j 1 and Cry j 2 in 24 symptomatic patients and six nonallergic subjects. In T-cell proliferation assays, mean stimulation indexes (SI) were 10.6 for Cry j 1 and 11.7 for Cry j 2 stimulation, respectively, in the allergic patients. Two of the nonallergic subjects showed strong T-cell proliferation to both allergens, while the remainder did not. All the allergic subjects (17/17) showed high titers of anti-Cry j 1 IgE antibody at a mean value of 165 U/ml, whereas only 64% responded to Cry j 2 with low titers at a mean value of 26 U/ml. Nonallergic subjects did not respond with IgE production. Allergic subjects were further examined for their cytokine production profiles. All allergic subjects tested (16/16) produced high levels of interferon-gamma (IFN-gamma) in response to Cry j 1 with a mean value of 918 pg/ml, while only five subjects showed significant elevation of IFN-gamma production in response to Cry j 2 with a mean value of 679 pg/ml. The remainder produced small amounts of IFN-gamma. Cry j 1 induced higher levels of interleukin (IL)-10 gene expression than did Cry j 2 stimulation, while both allergens induced IL-4 expression at a similar level. The IL-12 p35 gene was constitutively expressed, whereas the IL-12 p40 gene expression in Cry j 1-stimulated cells was elevated eightfold over that of nonstimulated cells. Increased expression of the IL-12 p40 gene was negligible in Cry j 2-stimulated cells. Thus, Cry j 1 stimulated mixed features of Th1 and Th2-like responses, while Cry j 2 played a minor role in inducing IgE production and cytokine (IFN-gamma, IL-10, and IL-12) production, except for IL-2 production and strong T-cell proliferative activity. Therefore, it was concluded that Cry j 1 is the more important allergen, and that T-cell proliferation assays do not necessarily reflect the level of allergenicity.

Allergens↗

PubMed1996

Immunodominance of seven regions of a major allergen, Cry j 2, of Japanese cedar pollen for T-cell immunity.

The immunodominant regions of the Japanese cedar pollen allergen Cry j 2 for T-cell immunity were determined with whole peripheral blood lymphocytes (PBL) derived from seven allergic patients and three nonallergic subjects. Cry j 2-stimulated T-cell proliferation was inhibited by anti-HLA-DR, but not by anti-HLA-DQ antibody, indicating that the responding T cells recognized the allergen peptides associated with HLA-DR molecules. It was found that seven regions of Cry j 2, i.e., regions corresponding to amino acid numbers 1-26, 70-84, 151-167, 187-203, 252-279, 283-314, and 345-362, were immunodominant for T-cell proliferation. Thus, Cry j 2 bears a limited number of immunodominant regions despite polymorphic features of HLA-DR in the immune system. This suggests the possibility of molecularly designing Cry j 2 antagonists that could downregulate allergic reactions to Japanese cedar pollen.

Case-Control Studies↗

PubMed1996

Role of the nondominant hemisphere and undamaged area during word repetition in poststroke aphasics. A PET activation study.

BACKGROUND AND PURPOSE: Although the resting regional cerebral blood flow (rCBF) in aphasic patients has been thoroughly investigated with positron emission tomography (PET) and single-photon emission CT, and PET studies in normal subjects have elucidated the functional localization of language processing, little is known about the activation pattern of language processing in aphasic patients. METHODS: We measured the changes in rCBF during a repetition task (hearing a single word and repeating it aloud) and the resting state using the H2(15)O PET activation technique in 6 normal subjects (mean +/- SD age, 58.3 +/- 8.1 years) and 16 aphasic patients: 10 fluent aphasics (age, 60.3 +/- 12.5 years) and 6 nonfluent aphasics (age, 50.5 +/- 8.3 years). RESULTS: In normal subjects, the posteroinferofrontal area (PIF) including Broca's area, the posterosuperotemporal area (PST) including Wernicke's area, the rolandic areas, and a few other areas were activated with left side dominance by the repetition task. In the resting state, the rCBF in the left PIF and the left posterotemporal area was reduced in both fluent and nonfluent aphasics. In aphasic patients, the magnitude of activation in the right PIF and PST by the repetition task was greater than in normal subjects. The increase in rCBF during the repetition task in the left PIF correlated with the Western Aphasia Battery score of spontaneous speech in the nonfluent aphasics with a left inferofrontal lesion. CONCLUSIONS: This study shows the importance in aphasic patients of the mirror regions of the left PIF and PST in the nondominant (right) hemisphere for performing the word repetition task. The results also show the importance for nonfluent aphasic patients of the recruitment of the undamaged PIF for spontaneous speech.

Adult↗

PubMed1996

[Benzodiazepine receptor and cerebral blood flow in early Alzheimer's disease--SPECT study using 123I-iomazenil and 123I-IMP].

This study was designed to investigate benzodiazepine receptors (BZR) and cerebral blood flow (CBF) in patients with early Alzheimer's disease. Imaging of BZR and measurement of CBF were performed by SPECT using 123I-Iomazenil (IMZ) and 123I-IMP respectively, in seven patients with early Alzheimer's disease and five patients with unilateral left cerebral infarction as controls. The values for the normal cerebral hemisphere (ratio to the contralateral cerebellum) in patients with cerebral infarction were adopted as control values. In patients with Alzheimer's disease, the CBF (ratio to cerebellum) decreased significantly in the frontal cortex and the parietal cortex compared with the control values. There was no significant difference in late IMZ SPECT counts (ratio to cerebellum) and washout (the ratio of late-to-early IMZ SPECT counts) between patients with Alzheimer's disease and the controls. However, the late IMZ SPECT counts and washout decreased in one patient with moderate dementia. There was a significant correlation between the severity of dementia and the late IMZ SPECT counts in the temporal cortex and the parietal cortex. These results suggest that benzodiazepine binding sites are relatively well preserved in patients with early Alzheimer's disease, and reduction of the CBF is caused by neuronal dysfunction rather than by neuronal loss. IMZ SPECT study is useful and necessary for clarifying the pathophysiological state in Alzheimer's disease.

Aged↗

PubMed1996

[A quantitative study of regional cerebral blood flow in patients with dementia of Alzheimer type using single photon emission computed tomography--clinical application of the IMP autoradiographic method (IMP ARG method)].

We quantitatively measured regional cerebral blood flow (rCBF) in 37 patients with dementia of Alzheimer type (DAT) to investigate the clinical utilities of the N-isopropyl-p-[123I]iodoamphetamine autoradiographic method (IMP ARG method) that is a quantitative method more simplified and less invasive for IMP-SPECT developed by Iida et al. A given standard input function and a given value of distribution volume (Vd) used for the rCBF measurement of this method were calculated from the dynamic study by six normal volunteers. Mean values [SD] of rCBF (ml/ 100 g/min) in the Cerebral Cortex were 49.0 [6.0] in the controls (n = 20), 42.6 [5.9] in mild DAT group (n = 14), 36.7 [5.5] in moderate DAT group (n = 12), and 26.4 [7.5] in severe DAT group (n = 11), respectively. These values were significantly different between each neighboring group. Moreover, the correlations between the score by the Hasegawa dementia scale (HDS-R) and each rCBF were significant in the temporal, parietal, and frontal cortex. These findings suggest that the rCBF measurement in IMP-SPECT using this method is useful for the diagnosis of the clinical severity in patients with DAT.

Aged↗

PubMed1996

[Two siblings with familial schizencephaly--report of a family and review in relation to clinical features and neuroradiological findings].

We examined 2 siblings with schizencephaly. A 23-year-old female (Case-1) had a mild left hemiparesis, and her 25-year-old brother (Case-2) presented a quadriplegia. Both cases achieved a borderline intellectual level and both had seizure disorders. The magnetic resonance imaging (MRI) of Case-1 revealed thickened gray matter around the fused schizencephalic clefts in the bilateral frontal lobes, mild ventricular enlargement and absence of the septum pellucidum. And, the MRI result of Case-2 disclosed similar but more severe abnormalities. The positron emission tomography (PET) using 18F-Fluoro-2-deoxy-D-glucose of Case-1 demonstrated focal hypermetabolic activity in the ectopic gray matter with the absence of epileptic discharges on the electroencephalogram on the day of PET study. And the single photon emission computed tomography (SPECT) using 123I-N-isopropyl-p-iodoamphetamine of Case-1 delineated focal hyperperfusion in the same lesions. The PET and SPECT findings are unique, since previous reports have indicated focal hypoperfusion and hypometabolism in abnormal gray matter. Familial schizencephaly is a very rare malformation, and this is the first report of that in Japan. Further evaluation in similar cases is needed to determine the pathophysiology of this anomaly.

Adult↗

PubMed1996

Maxillary osteomyelitis secondary to osteopetrosis.

A 41-year-old Japanese woman complained of a gradually enlarging swelling of her left cheek for seven months. She was diagnosed with osteopetrosis by standard skeletal radiographs, and her cheek swelling was diagnosed as maxillary osteomyelitis secondary to osteopetrosis. She underwent a left partial maxillectomy, and her post-operative course was stable with no complications. A literature review is also presented.

Adult↗