Biomedical subjects

T Himi

Publications and source records attributed to T Himi.

At least 55 records · Page 3Linked to original sources

PubMed1998

Antibodies specific to outer membrane antigens of Moraxella catarrhalis in sera and middle ear effusions from children with otitis media with effusion.

OBJECTIVE: Recent studies have shown that bacterial DNA is present in a significant percentage of middle ear effusions, suggesting that persistent bacterial infection may be more important in pathogenesis and recurrence of otitis media with effusion (OME) than previously considered. Although Moraxella (M.) catarrhalis is one of the most common pathogens of otitis media, relatively little is known about immune response to the organism. The objective of the present study is to investigate how systemic and local immune activities against M. catarrhalis may be associated with severity of OME. METHODS: The antibody levels specific to outer membrane antigens of M. catarrhalis in sera and middle ear effusions (MEEs) from 59 children with OME were measured by enzyme-linked immunosorbent assay. Their ages ranged from 1 to 12 years with a median 5.0 years. The children were followed 1 year prospectively and classified into two groups with or without recurrent/persistent OME according to severity of OME during the follow-up 1 year. RESULTS: Serum IgG, IgM, and IgA antibodies specific to outer membrane antigens of M. catarrhalis were detected in all samples and the median levels were 35, 0.93, and 1.2 microg/ml respectively. The MEE IgG, IgM, IgA, and secretory IgA antibodies were detected in over 95% samples tested and the median levels were 371, 158, 20, and 50 ng/mg total protein respectively. A comparison between acute and subacute/chronic phases revealed that the median levels of MEE IgG and IgM antibodies were higher at the acute phase (692 vs. 340, P = 0.06; 35 vs. 10, P = 0.02, respectively); while the MEE secretory IgA antibody level was increased at the subacute/chronic phase (74 vs. 35, P = 0.02). Either serum or MEE IgG antibody level was significantly lower in recurrent/persistent OME group than that in nonrecurrent/non-persistent OME group (13 vs. 43 ,microg/ml, P = 0.009; 238 vs. 577 ng/mg protein, P = 0.006, respectively). CONCLUSIONS: These data provide additional information on the immunologic aspects of children with OME. Decreased serum and MEE IgG antibody levels specific to outer membrane antigens of M. catarrhalis may lead to failure to eliminate this organism, resulting in persistent and/or recurrent appearance of MEE.

Antibodies, Bacterial↗

PubMed1998

Expression profile of vascular cell adhesion molecule-1 (CD106) in the middle ear using radiolabeled monoclonal antibody.

Adhesive interactions between leukocytes and endothelium are required for subsequent leukocyte extravasation toward inflammatory sites. Understanding the possible kinetic expression of vascular cell adhesion molecule-1 (VCAM-1) in the middle ear cavity during an inflammatory cascade in vivo may be important for clarifying local immunological responses in otitis media. Two inflammatory models were produced in the rat and involved acute middle ear mucosal and cutaneous inflammation induced after inoculation or intradermal injection of lipopolysaccharide (LPS). After intravenous injection of both 125I-labeled anti-VCAM-1 and 131I-labeled control monoclonal antibody (mAb), the kinetic expression of VCAM-1 in the middle ear and skin was assessed by local radionuclide uptake. The biodistribution of an 125I-labeled anti-VCAM-1 mAb as a potential detector of focal inflammation was examined in normal rats. Both inflammatory lesions were characterized by early and sustained (up to 24 h) expression of VCAM-1, with maximal expression at 4 h after LPS stimulation. The kinetics of VCAM-1 expression was similar among the middle ear mucosa or skin specimens studied and different stimulation methods. A similar biodistribution and clearance of radioactivity between 125I-labeled anti-VCAM-1 mAb and 131I- or 99mTc-labeled control mAb were observed. The present result suggest that functional VCAM-1 induced by LPS is expressed in both middle ear tissue and skin lesions and may play a role in the initial stage of inflammatory response produced. Although VCAM-1 upregulation is a very early event in the inflammatory cascade, 125I-labeled anti-VCAM-1 mAb may be useful for the early detection of focal inflammation in the middle ear.

Animals↗

PubMed1998

Intracranial facial nerve neurinoma: surgical strategy of tumor removal and functional reconstruction.

BACKGROUND: Three cases with intracranial facial neurinoma underwent tumor removal and facial nerve reconstruction with or without tympanoplasty. Surgical strategy for each case was tailored to: (1) the site of main tumor mass, (2) its extension along the facial nerve, and (3) involvement of the auditory organs. METHODS: Surgeries adopted in the three cases were: transpetrosal approach with intracranial-intratemporal facial nerve anastomosis, middle fossa and transmastoid approach with intratemporal facial nerve anstomosis and tympanoplasty, and middle fossa and transmastoid approach with intracranial-intratemporal facial nerve anastomosis and tympanoplasty. The greater auricular nerve was used as the nerve graft for all three cases. RESULTS: In the follow-up period of 8-13 months there was no tumor recurrence; facial function was scored 20/90 in modified May's scoring system in each case, but two are still in the process of functional recovery. One of the two cases who underwent tympanoplasty showed complete recovery of hearing within 1 month, and the other showed worsened hearing, which was not serviceable at 3 months postoperatively. CONCLUSION: Systematic surgical approach for tumor removal, facial nerve reconstruction, and auditory reconstruction should be considered in cases with intracranial facial neurinoma due to its varied clinical features.

Aged↗

PubMed1998

A caspase inhibitor blocks ischaemia-induced delayed neuronal death in the gerbil.

Caspases play a critical role in the cell death machinery in various cell types. Here we investigated the involvement of caspases in the delayed neuronal death after transient global forebrain ischaemia in the gerbil. Intrahippocampal injection of benzyloxycarbonyl-Asp-CH2-dichlorobenzene (zD), an irreversible inhibitor of caspases, saved hippocampal CA1 neurones from chromatin condensation and DNA fragmentation at post-ischaemia day 4, and these neurones maintained normal morphology at day 8 post-insult. Intrahippocampal injection of interleukin-1beta (IL-1beta) after ischaemic insults did not influence the neuroprotective effect of zD, suggesting that the neuroprotective effect does not depend on the inhibition of mature IL-1beta production. Animals that received zD-injection showed significant improvement in step-through and step-down passive avoidance learning at post-ischaemia days 4 and 5, suggesting that neural functions were preserved in these animals. At post-ischaemia day 4, the cleavage of poly(ADP-ribose)polymerase was observed, and this cleavage was almost completely suppressed in zD-injected hippocampus, suggesting involvement of caspase-3 and caspase-3-like caspase in the delayed neuronal death. Our findings indicate that caspases play important roles in the delayed neuronal death after transient global forebrain ischaemia in the gerbil, and suggest that ischaemia-induced brain damage can be blocked by caspase inhibitors.

Animals↗

PubMed1998

[Clinical study of hypopharyngeal carcinoma].

A clinical study was performed of 83 patients with hypopharyngeal cancer treated in the Sapporo Medical University Hospital from 1982 to 1995. Five-year cumulative survival rate was 34.9% in the whole group and 37.2% in the radical surgical and/or radiation treatment group. In the radiation treatment group, the patients with T1, T2, N0 or N1 stage disease, especially those whose original disease responded almost completely to 40Gy irradiation, showed high tumor control rates following full-dose irradiation with or without radical neck dissection. In the radical surgery group, the patients with T4 or N2 stage disease showed better prognosis than those in the radiation group. However, among the patients with N3 lymph node metastases, there were no long-term survivors in either the radiation or the surgery groups.

Adult↗

PubMed1998

Simple and Patlak models for myocardial blood flow measurements with nitrogen-13-ammonia and PET in humans.

UNLABELLED: The Simple and Patlak models for estimating myocardial blood flow with 13N-ammonia have become attractive for clinical applications with PET because of their simplicity and ease of implementation. However, these models are sensitive to factors such as the data acquisition times and data integration times, which can cause errors in the estimation of myocardial blood flow, as demonstrated in this study. Limiting the application of these models to specific conditions can minimize the errors. METHODS: Dynamic PET images of the uptake of 13N-ammonia in the heart were obtained in seven humans under rest and dipyridamole stress. Myocardial blood flow was estimated using the Simple and Patlak models for different data acquisition times and data integration times. Blood flow values were compared to flow values computed with the two-compartment model as a reference. RESULTS: Blood flow values calculated with the Simple and Patlak models during the first 2 min of data acquisition were closely correlated to the two-compartment model values. Longer acquisition times resulted in significant underestimation of blood flow for the Simple model. Long integration times of greater than 60 sec also resulted in significant underestimation of blood flow for both models. CONCLUSION: The Simple and Patlak models produce estimates of myocardial blood flow that are well correlated with the two-compartment model estimated blood flows for the integration time of 60 sec from 60 to 120 sec postinjection. Because of the errors associated with longer data acquisition times and longer integration times, use of these models should be limited to a well-documented data acquisition paradigm.

Ammonia↗

PubMed1997

Influence of age on the production of interleukin-8-like chemokine (GRO/CINC-1) in rat nasal mucosa.

The ability of the nasal mucosa to produce various cytokines has been shown to correlate closely with the capacity to regulate an inflammatory condition in the nasal cavity. Immune senescence is characterized by a dysregulation of the immune system. This change is reflected by the altered production of cytokines during aging. We measured the in vivo production and gene expression of IL-8-like cytokines (GRO/CINC-1) in nasal lavages and mucosa from young (2- to 4-week-old and 11- to 15-week-old) and older (81-to 98-week-old) rats by using enzyme-linked immunosorbent assays and reverse transcription-polymerase chain reactions. Significant increases of GRO/CINC-1 levels were found in unstimulated nasal lavages of the older rats compared to that of the 2- to 4-week-old animals. GRO/CINC-1 showed time-dependent production with lipopolysaccharide (LPS) stimulation in nasal lavages. The GRO/CINC-1 production reached a plateau by 4 h with LPS in any group. However, the manner of the initial time course showed no significant differences among these three groups. At the time of peak production of GRO/CINC-1, messenger RNA for the GRO/CINC-1 was found to be induced in the nasal mucosa. These findings may be important for understanding the mechanisms of the altered immune response and inflammation in the nasal cavity associated with aging.

Aging↗

PubMed1997

In vitro regulation of neutrophil migration by beta 2 integrins (LFA-1 and Mac-1) in patients with otitis media.

Beta 2 integrins are located on the surface of neutrophils and have important roles in cell migration to an inflammatory site. We investigated the inhibitory effect of antibodies to the beta 2 integrin family for neutrophil migration into middle ear effusion (MEE) during acute otitis media in children and chronic otitis media with effusion in both children and adults. Neutrophil migration to MEE samples was assessed in vitro in a 48-well Boyden chamber. The migration index value and the activity of chemoattractants in MEE was found to be proportional to the number of infiltrated cells. Migration of activated neutrophils into MEE was significantly inhibited by blocking surface-expressed cell adhesion molecules (CAM) with anti-CD11b (Mac-1 alpha) and anti-CD18 (common beta 2 subunit) antibodies (P < 0.001) but not with anti-CD11a (LFA-1 alpha) antibody. These inhibitory effects of anti-CAM antibodies were found in all types of MEE in all age groups studied. A new therapeutic approach to inflammation has been considered recently that utilizes inhibition of neutrophil migration with a blocking antibody to CAM. Our in vitro data support a possible therapeutic effect of anti-CAM antibody, indicating that administration of anti-CD11b and CD18 antibodies may be useful for treating human otitis media.

Adolescent↗

PubMed1997

Effect of radiotherapy on the levels of secretory immunoglobulin A against indigenous and virulent streptococci.

It is well known that the frequency of upper respiratory infection is clinically increased after radiotherapy of the head and neck region. This study found higher antibacterial secretory immunoglobulin A (S-IgA) activity against three indigenous streptococci (Streptococcus mitis, S. salivarius, and S. sanguis I) and S. pneumoniae in patients who had undergone radiation therapy of the head and neck region than in control subjects. This showed no relation to the extent of the radiation field. Compared with before radiotherapy, the S-IgA titer against S. pneumoniae and its ratio to the activities against the indigenous streptococci were significantly higher in patients with fully irradiated major salivary glands. These results indicated that the radiotherapy promoted the antigen-specific S-IgA production of virulent streptococci in most patients with head and neck cancer, even more than 6 months after radiotherapy. The resulting altered balance in the S-IgA system of normal indigenous streptococci may also impair the ability to maintain the stable bacterial interference between normal indigenous and virulent streptococci in the oropharyngeal cavity.

Aged↗

PubMed1997