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Biomedical subjects

Y Nakai

Publications and source records attributed to Y Nakai.

At least 163 records · Page 9Linked to original sources
PubMed1998

Clinical value of MRA analysis of the vertebrobasilar system in vertiginous patients.

Vertebrobasilar haemodynamics correlate closely with syndromal vertigo. The aim of this study is to examine the clinical value of MRA for evaluation of vertebrobasilar haemodynamics in vertiginous patients. We examined 40 individuals (20 with vertebrobasilar insufficiency and 20 diagnosed with other vestibular disorders). MRA results were quantified on the basis of the severity of vascular stenosis in the major arteries of the vertebrobasilar system and we analysed the relationship of these results with otoneurological diagnoses, eye-tracking tests (ETT) and optokinetic nystagmus (OKN). MRA results correlated well with otoneurological diagnoses and ETT results. Consequently, MRA can be used as a screening examination to evaluate vertebrobasilar haemodynamics and ETT may be a sensitive functional parameter of vertebrobasilar insufficiency.

Adult↗
PubMed1998

Evaluation of the vertebrobasilar artery system by magnetic resonance angiography in the diagnosis of vertebrobasilar insufficiency.

To evaluate the advantages of magnetic resonance angiography (MRA) in assessing the vertebrobasilar artery system for diagnosing vertebrobasilar insufficiency (VBI), we compared the MRA results of middle-aged and older VBI cases with those of age-matched peripheral disorder cases. There were no significant differences in the rate of complications associated with atherosclerosis between VBI cases and peripheral disorder cases. The MRA results were quantitatively assessed by scores determined on the basis of the severity of stenosis in the vertebral arteries and basilar artery. The MRA score was defined as the total score of these three arteries. The severity of stenosis and the MRA score of VBI cases were significantly higher than those of peripheral cases. MRA can therefore be of value as a screening examination for estimating vertebrobasilar blood flow and can provide helpful information for diagnosing VBI.

Aged↗
PubMed1998

Quantitative analysis of correlation between smooth pursuit and vertebrobasilar hemodynamics.

The cerebellar arterial system is derived from the vertebrobasilar system. However, the relation between cerebellar function and vertebrobasilar hemodynamics remains poorly understood. In this study on patients with vertebrobasilar insufficiency symptoms we examined the relation between magnetic resonance angiography (MRA) abnormalities in the vertebrobasilar system and smooth pursuit function, which is a sensitive parameter of cerebellar function. MRA abnormality was quantitatively assessed on the basis of the severity of stenosis in the vertebral arteries and basilar artery, and on the visualization of the superior cerebellar arteries. Smooth pursuit dysfunction was quantified by the combined amplitude of spikes on an electronystagmograph. A significant correlation was found between MRA abnormality and smooth pursuit dysfunction. This suggests that smooth pursuit dysfunction is closely related to static factors of dysregulation of vertebrobasilar blood flow. Therefore, smooth pursuit can be valued as a sensitive parameter to dysfunction of vertebrobasilar blood flow.

Aged↗
PubMed1998

Interleukin-6 and tumour necrosis factor alpha synthesized by cholesteatoma cells affect mucociliary function in the eustachian tube.

The aims of this study were to investigate the possible synthesis of IL-6 and TNF-alpha by cholesteatoma cells in culture and the effect of IL-6 and TNF-alpha produced by cultured cholesteatoma cells on the function of the mucociliary system in the tubotympanum. Cholesteatoma cells were collected from 10 patients, and the medium supernatants in which cholesteatoma cells or normal human epidermoid cells had been cultured for 48 h were collected. The concentrations of IL-6 and TNF-alpha in the supernatants were measured by enzyme-linked immunosorbent assays. The effect of the culture supernatants on ciliary activity was examined using an in vitro experimental system. The supernatants were injected into the tympanic cavities of guinea pigs, and mucociliary clearance time of the Eustachian tube was determined according to our dye transport technique 24 h after the intratympanic injection. Human cholesteatoma cells produced larger amounts of IL-6 and TNF-alpha than normal human epidermoid cells. The supernatants of cholesteatoma cells compromised ciliary activity and mucociliary clearance of the Eustachian tube in the guinea pigs. The effects of the supernatants of cholesteatoma cells on the ciliary activity and mucociliary clearance were correlated with the concentration of IL-6 and TNF-alpha in the supernatants. In conclusion, cholesteatoma cells can produce IL-6 and TNF-alpha, which are able to compromise the mucociliary function in the tubotympanum. IL-6 and TNF-alpha produced in middle ear cholesteatoma might aggravate the disease by the wide range of their biological activities on the mucociliary system, the proliferation of cholesteatoma cells and the bone metabolism.

Adult↗
PubMed1998

Suppression of seasonal increase in serum interleukin-5 is linked to the clinical efficacy of immunotherapy for seasonal allergic rhinitis.

Although immunotherapy is recognized as a highly effective form of treatment for allergic rhinitis, especially pollen-induced seasonal allergic rhinitis, the mechanisms have not been fully established. In the present study, we investigated whether immunotherapy could affect the seasonal increase in interleukin-5 (IL-5) in the serum of patients with seasonal allergic rhinitis and whether the effect on IL-5 in serum is related to the clinical efficacy of immunotherapy. Venous blood was collected twice from each patient with seasonal allergic rhinitis due to Japanese cedar pollens, before and during the cedar pollen season in 1997, to determine the cedar pollen-specific IgE and IL-5 in serum. Both specific IgE and IL-5 in serum were significantly increased during the pollen season, not only in the poor responders to antihistamines but also in the good responders. Neither the rate of seasonal increase in specific IgE nor the rate of seasonal increase in IL-5 differed significantly between the good responders and the poor responders to antihistamines. Both specific IgE and IL-5 were significantly increased during the pollen season in the poor responders to immunotherapy, whereas neither specific IgE nor IL-5 was increased during the pollen season in the good responders to immunotherapy. The rate of seasonal increase in specific IgE as well as IL-5 was significantly smaller in the good responders than in the poor responders to immunotherapy. The rates of seasonal increase in specific IgE and in IL-5 were inversely correlated with the length of time on immunotherapy. However, the rate of seasonal increase in specific IgE was not significantly correlated with the rate of seasonal increase in IL-5. In conclusion, the suppression of the seasonal increase in IL-5 in serum is a working mechanism of immunotherapy related to the clinical efficacy of the treatment.

Adult↗
PubMed1998

Seasonal changes in phytohemagglutinin-induced cytokine synthesis by peripheral blood lymphocytes of patients with seasonal allergic rhinitis due to Japanese cedar pollens.

We investigated the seasonal changes in non-specific stimulation-induced cytokine production by peripheral blood mononuclear cells (PBMCs) in patients with seasonal allergic rhinitis due to Japanese cedar pollen. This study included 16 non-allergic healthy adult volunteers and 115 patients with detectable levels of Japanese cedar pollen-specific IgE in their serum. The 115 patients were divided into five groups, an asymptomatic group (specific IgE was positive but there were no nasal symptoms), a medication group (typical symptoms of Japanese cedar pollinosis and treated with antihistamine tablets), a good-IT group (responded well to immunotherapy), a poor-IT group (responded poorly to immunotherapy) and a cure group (no symptoms after discontinuation of immunotherapy). PBMCs (1.0 x 10(6) cells/ml) were collected before and during the cedar pollen season in 1998, and were cultured for 24 h in the presence of 10 micrograms/ml phytohemagglutinin. The concentrations of IL-4, IL-5 and IFN-gamma in the culture supernatants were measured by an enzyme-linked immunosorbent assay. None of the levels of IL-4, IL-5 and IFN-gamma synthesized by PBMCs in the asymptomatic group, medication group, good-IT group, poor-IT group or cure group were significantly different from those in the non-atopic group. In the medication group, the synthesis of TH2-type cytokines (both IL-4 and IL-5), but not of TH1-type cytokine (IFN-gamma) was significantly increased during the pollen season compared with before the pollen season, whereas in the non-atopic group, the synthesis of IL-4, IL-5 and IFN-gamma did not differ significantly before and during the pollen season. The synthesis of both IL-4 and IL-5 was significantly increased during the pollen season in the poor-IT group, whereas the synthesis of IL-4 and IL-5 was not increased during the pollen season in the good-IT or cure groups. In conclusion, our study demonstrates that T-cell reactivity to non-specific stimulation outside of the pollen season did not differ between the patients with seasonal allergic rhinitis and non-atopic individuals, that T-cells in patients with seasonal allergic rhinitis are affected or primed by the natural pollen exposure to synthesize TH2-type cytokines even in response to non-specific stimulation, and that successful immunotherapy could decrease the natural pollen exposure-primed hyperreactivity of TH2 cells to non-specific stimulants.

Adult↗
PubMed1998

Allergen-specific immunotherapy for allergic rhinitis: a new insight into its clinical efficacy and mechanism.

Immunotherapy has been used widely for allergic diseases for more than 90 years but, in the opinion of many physicians, it is still a controversial form of treatment. The exact mechanism of action of immunotherapy remains to be determined. In the present study, we review the clinical efficacy and mechanism of action of immunotherapy for allergic rhinitis. Recent double-blind placebo-controlled studies have demonstrated the clinical efficacy of immunotherapy for allergic rhinitis. This therapeutic method has several advantages over conventional pharmacological treatment. Immunotherapy is inferior to pharmacological treatment in the short term, but in the long term it is substantially superior with respect to clinical efficacy. Immunotherapy has the potential permanently to alleviate the abnormal immunological responses of allergic rhinitis and to cure the nasal symptoms in the long term, even after discontinuation of injections. In addition, immunotherapy can prevent the onset of new sensitizations in allergic patients and may prevent the progression of rhinitis to asthma. It may therefore be possible for immunotherapy to alter the natural history of allergic sensitization and its clinical manifestation. These lines of clinical evidence could affect strategies of long-term therapy for allergic rhinitis. Modern molecular biological techniques have suggested that immunotherapy may affect allergen-induced TH responses or cytokine profiles, but there is no general agreement among investigators. However, IL-5 is likely to be the most important cytokine involved in the clinical efficacy of immunotherapy, and the suppression of allergen-induced IL-5 synthesis is most likely to be involved in the mechanism of immunotherapy. Our recent investigations, focusing on specific IgE and IgG4 responses, suggest that immunotherapy-induced changes in these specific antibodies play a clinical role and are involved in the mechanism of action of immunotherapy. It is probable that immunotherapy modulates and affects many different immunological and non-immunological phenomena to produce clinical efficacy and that clinical improvement is a consequence of different mechanisms over time.

Allergens↗
PubMed1998

An epidemiological study of postviral olfactory disorder.

Postviral olfactory disorder develops after infection with the common cold, and is a relatively severe and prolonged disorder without rhino-sinusitis. This epidemiological study aimed to characterize its clinical pathology and determine the causative virus. Postviral olfactory disorder occurs most commonly in middle-aged women and is most prevalent in spring and summer. A comparison of the monthly frequency of the disorder with the incidence of isolation of various viruses suggest that the influenza virus, respiratory syncytial virus, and herpes virus are not causative viruses, while parainfluenza virus type 3 is most likely to be a causative virus. This conclusion is supported by immunological study and analysis of symptoms of the cold. All patients with postviral olfactory disorder had increased serum antibody titre for parainfluenza virus type 3. No prominent or specific symptoms of common cold were identified as a potential trigger of this syndrome in patient questionnaires.

Adult↗
PubMed1998

Effect of zinc sulfate on sensorineural olfactory disorder.

We administered zinc sulfate to patients with sensorineural (post-viral, post-traumatic, or unknown aetiology) olfactory disorder and examined its effects. The patients were divided into three groups by method of treatment: zinc sulfate only, combination of zinc sulfate and the usual therapy, or the usual therapy. For disorders of post-viral and unknown aetiologies, there were no significant differences in improvement among the three groups. However, for post-traumatic olfactory disorder, the zinc sulfate groups had significantly higher improvement rates than did the group that received the usual therapy. The difference between post-traumatic and post-viral olfactory disorders in the effect of zinc sulfate therapy appeared to depend on the pathology of the associated lesions. In cases of post-traumatic olfactory disorder, regenerative capacity is retained in the olfactory epithelium because the blast cells of olfactory receptor cells remain intact. However, for post-viral olfactory disorder, the lack of olfactory receptor cells and blast cells due to viral infection results in loss of regenerative capacity. We also determined pre-treatment serum zinc concentrations in those patients who planned to be treated with zinc sulfate. Pre-treatment serum zinc concentration was not significantly related to improvement rates.

Craniocerebral Trauma↗
PubMed1998

Comparative assessment of cell proliferation and accumulation of extracellular matrix in nasal polyps.

In nasal polyps constantly associated with chronic inflammation, a dysregulation of epithelial cell proliferation has been described. Involvement of extracellular matrix accumulation is also suggested in the formation and growth of nasal polyps. In this study, we attempted to evaluate the activity of the proliferation of epithelial cells and fibroblasts and the relation between fibronectin accumulation and these cell proliferations in nasal polyps. The pathological specimens of 30 patients were examined which manifested proliferating cell nuclear antigen (PCNA) expression in epithelial cells and fibroblasts and in fibronectin expression. PCNA expression was quantified by calculating the index for each sample. No significant difference in PCNA index was found between epithelial cells and fibroblasts. However, a significant correlation was found between the epithelial and fibroblastic PCNA index. In addition, fibronectin immunopositivity was well correlated with the activity of proliferation of fibroblasts. Therefore, proliferation of fibroblasts is also an important factor in the growth of nasal polyps, and its relationship with fibronectin accumulation may play a role in the pathogenesis of nasal polyposis.

Adult↗
PubMed1998

Fluorine-18 fluorodeoxyglucose positron emission tomography imaging of parotid mass lesions.

Using X-ray CT or magnetic resonance imaging (MRI), fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) studies were performed in 28 patients with parotid lesions. All lesions except two showed higher accumulation of FDG than normal parotid gland. High accumulation was found in all of 5 carcinomas, all of 6 Warthin's tumors, and 8 of 12 pleomorphic adenomas, with standardized uptake values (SUVs) over 3.0. The mean SUVs of carcinomas, Warthin's tumors, and pleomorphic adenomas were 5.92 +/- 2.05, 7.03 +/- 2.49, and 4.07 +/- 1.55, respectively. On the other hand, all 5 inflammatory lesions demonstrated low accumulation, with mean SUVs of 1.66 +/- 0.89. It is thus difficult to differentiate malignant from benign parotid lesions by SUV on FDG-PET.

Adult↗
PubMed1998

Roxythromycin reinforces epithelial defence function in rabbit trachea.

Our study elucidates the effect of roxythromycin (RXM) on airway epithelial defence functions, especially the mucociliary and epithelial barrier functions, in the rabbit trachea. In vitro ciliary activity was not affected in the presence of 3.3 mg/ml of RMX, but was enhanced in the presence of 6.7 mg/ml of RXM. Oral administration of 10 and 100 mg of RXM for 14 days enhanced both ciliary activity and mucociliary transport velocity in the trachea. Epithelial permeability to fluorescein isothiocyanate-dextrans (FD-70s; molecular weight: 70,000 daltons) was not affected by oral administration of 10 mg of RXM for 14 days, but was significantly reduced by oral administration of 100 mg of RXM for 14 days. Inhalation of platelet activating factor (PAF) compromised the function of the mucociliary system and the tight junction barrier. However, pretreatment with 20 mg of RXM significantly alleviated the PAF-induced decrease in mucociliary function and the increase in epithelial permeability to FD-70s. In conclusion, such reinforcement of the epithelial defence functions is likely to be involved in the pharmacological action underlying the clinical efficacy of RXM for chronic airway inflammatory disease.

Animals↗
PubMed1998

Twenty years of statistics and observation of facial bone fracture.

We analyse the details of patients with facial bone fractures who visited us from 1993 to 1997, and compare past cases treated from 1978 to 1992. From 1993 to 1997, the total numbers of patients and fractures were 633 and 697, respectively. Thus, we had 127 patients and 139 fractures annually. The number of patients has increased over the years. The highest occurrence rate of facial bone fracture was in the nasal bone (half of all), followed by the malar bone, blowout fractures and the mandibular bone. The rate was the lowest in the maxillary bone. The ratio of males to females was 7:3. Facial bone fractures were most often seen in the 10-29 age group.

Adolescent↗
PubMed1998

Our treatment of cleft lip and cleft palate.

Our principle in cleft lip and cleft palate repair is all-round personal treatment. That is, treatment concentrates not only on cleft lip and cleft palate repair, but also considers the patient comprehensively in terms of his or her personality. In this report, we present patients with cleft lips and/or cleft palates for whom we performed surgical treatments in the past 25 years. We performed primary operations for 402 patients and secondary operations for 120. Cleft lip and cleft palate should be managed with consideration for otolaryngeal aspects as well as plastic surgical ones because of the nature of the disease. We therefore treated our patients from the standpoints of both medical fields, and gained much appreciation from parents whose children suffered from the congenital anomaly.

Child↗
PubMed1998

Immunotherapy decreases seasonal rise in serum-soluble CD23 in seasonal allergic rhinitis.

There is increasing in vitro evidence that soluble CD23 (sCD23) is capable of potentiating IgE synthesis, but the in vivo physiologic significance remains to be established. This study investigated the seasonal changes in sCD23 in patients with seasonal allergic rhinitis. It included 112 adult patients with seasonal allergic rhinitis due to Japanese cedar pollens and 20 nonatopic healthy volunteers. The 64 patients of the pharmacotherapy group were treated with nonsedating antihistamine tablets alone throughout the pollen season and the remaining 48 patients of the immunotherapy group continued to be treated with immunotherapy. Serum concentrations of sCD23 were measured in each patient, before and during the pollen season of 1996, by a sandwich enzyme-linked immunosorbent assay. The serum levels of sCD23 in the pharmacotherapy group before the pollen season were significantly higher than those in the nonatopic group (P = .0130) and those in the immunotherapy group (P = .0316). Seasonal increase in sCD23 was significant in the pharmacotherapy group, irrespective of the clinical response (P < .0001). By contrast, sCD23 was not significantly increased in the good responders to immunotherapy (P = .1826), but was significantly increased in the poor responders to immunotherapy (P = .0052). A significant correlation between seasonal increase in rate in specific IgE and seasonal increase in rate in sCD23 was confirmed in both the pharmacotherapy group (rs = 0.321, P = .0107) and the immunotherapy group (rs = 0.474, P = .0012). In conclusion, seasonal rise in sCD23 is associated with and is probably involved in seasonal rise in specific IgE in patients with seasonal allergic rhinitis, and successful immunotherapy is capable of blunting seasonal increase in sCD23, thus resulting in attenuation of seasonal increase in specific IgE and clinical benefits during the pollen season.

Adult↗
PubMed1998

Power Doppler findings of adenoma malignum of uterine cervix.

Adenoma malignum (minimum deviation adenocarcinoma) is a rare neoplasma of the uterine cervix, the diagnosis of wich cannot be determined by cervical smear. Recently, magnetic resonance imaging (MRI) was reported as useful for its diagnosis, but differentiation of adenoma malignum from deep-seated nabothian cysts remains problematic. We report here a case of adenoma malignum of the uterine cervix, for which MRI findings could not neglect deep-seated nabothian cysts. However, transvaginal power Doppler ultrasonography clearly showed richness of small vessels, whose arterial flow had higher velocity in the diastolic phase, around the cystic lesion of the uterine cervix. These findings indicate that, at least in the case reported here, transvaginal power and pulsed Doppler ultrasonography is a useful tool for the diagnosis of adenoma malignum of the uterine cervix.

Adenocarcinoma↗
PubMed1998

Effects of platelet activating factor on the tubotympanic mucosa and inner ear in the guinea pig.

The effect of platelet activating factor (PAF) was studied to elucidate its role in the pathogenesis of otitis media and sensorineural hearing loss. The PAF alone did not induce a reduction of ciliary activity of the cultured middle ear mucosa. However, a dose-dependent decrease in ciliary activity was observed in the presence of the medium containing both PAF and macrophages. Intravenous injection of PAF did not induce dysfunction of the mucociliary system or morphologic changes of epithelium in the tubotympanum, but cytoplasmic vacuolization and ballooning were observed in the inner ear within 1 hour after injection of PAF. In contrast, intratympanic injection of PAF induced mucociliary dysfunction and some pathologic changes in the tubotympanum. Intratympanic inoculation of PAF induced no pathologic findings in the inner ear. These results suggest that PAF is at least partially involved in the pathogenesis of certain middle ear diseases such as otitis media with effusion. Additionally, PAF might be involved in the pathogenesis of some types of unexplained sensorineural hearing loss.

Animals↗