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Biomedical subjects

Koichi Tomoda

Publications and source records attributed to Koichi Tomoda.

10 recordsLinked to original sources
PubMed2006

Difference of pharyngeal morphology and mechanical property between OSAHS patients and normal subjects.

OBJECTIVE: The intrinsic properties such as baseline caliber and compliance of upper airway are thought to be important in the pathogenesis of obstructive sleep apnea hypopnea syndrome (OSAHS). Our study was designed to detect the difference of baseline caliber (morphological property) of pharynx during both wakefulness and sleep, and difference of pharyngeal compliance (mechanical property) between OSAHS patients and normal subjects. METHODS: CT scan was performed on 7 normal subjects and 13 OSAHS patients when they are awake, during drug-induced sleep with minimally effective therapeutic pressure (P(eff)), 0 cmH2O, and critical pressure (P(crit)) being given via a nose mask system, respectively. 3D images of pharyngeal airway were reconstructed, and volume of each subdivision of pharynx was measured. Volume, average area and compliance of each subdivision and in total were compared between the two groups. RESULTS: The OSAHS group was shown to have a smaller average area at upper (1.20+/-0.26 cm2 versus 1.57+/-0.17 cm2, p<0.05) and middle part of pharynx (1.89+/-0.52 cm2 versus 2.58+/-0.27 cm2, p<0.05) during wakefulness. During sleep, this difference was shown to be even more obvious at upper part (0.77+/-0.30 cm2 versus 1.45+/-0.18 cm2, p<0.01); and middle part, (1.15+/-0.47 cm2 versus 2.44+/-0.26 cm2, p<0.01). The average area during wakefulness and sleep was also shown to be highly correlated. OSAHS group had a higher compliance at middle part (0.28+/-0.15 cmH2O(-1) versus 0.13+/-0.07 cmH2O(-1), p<0.05) of pharynx. CONCLUSION: We conclude that OSAHS patients have a narrower and more collapsible upper airway than normal subjects do, the caliber data obtained during wakefulness could reflect the baseline caliber during sleep, and our method is valid to evaluate both morphology and function of upper airway.

Adult↗
PubMed2006

Evidence for activation of nuclear factor kappaB in obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a risk factor for atherosclerosis, and atherosclerosis evolves from activation of the inflammatory cascade. We propose that activation of the nuclear factor kappaB (NF-kappaB), a key transcription factor in the inflammatory cascade, occurs in OSA. Nine age-matched, nonsmoking, and non-hypertensive men with OSA symptoms and seven similar healthy subjects were recruited for standard polysomnography followed by the collection of blood samples for monocyte nuclear p65 concentrations (OSA and healthy groups). In the OSA group, p65 and of monocyte production of tumor necrosis factor alpha (TNF-alpha) were measured at the same time and after the next night of continuous positive airway pressure (CPAP). p65 Concentrations in the OSA group were significantly higher than in the control group [median, 0.037 ng/microl (interquartile range, 0.034 to 0.051) vs 0.019 ng/microl (interquartile range, 0.013 to 0.032); p = 0.008], and in the OSA group were significantly correlated with apnea-hypopnea index and time spent below an oxygen saturation of 90% (r = 0.77 and 0.88, respectively) after adjustment for age and BMI. One night of CPAP resulted in a reduction in p65 [to 0.020 ng/mul (interquartile range, 0.010 to 0.036), p = 0.04] and levels of TNF-alpha production in cultured monocytes [16.26 (interquartile range, 7.75 to 24.85) to 7.59 ng/ml (interquartile range, 5.19 to 12.95), p = 0.01]. NF-kappaB activation occurs with sleep-disordered breathing. Such activation of NF-kappaB may contribute to the pathogenesis of atherosclerosis in OSA patients.

Adult↗
PubMed2006

[Adjuvant chemotherapy with TS-1 for head and neck cancer--side effect of two-week application followed by one-week rest regimen].

Multimodality therapy incorporated with radiotherapy, surgery and chemotherapy are used in the treatment of head and neck cancer in order to improve the local control and survival rate. TS-1, a newly developed oral antitumor agent which could achieve the same therapeutic concentration as that of 5-FU under continuous and intravenous treatment, has been used as adjuvant therapy for carcinomas in recent years. We presented our experience applying a new regimen of TS-1 and its side effects. TS-1 has been applied for head and neck carcinomas since 2001. The oral application of TS-1 has been used in 32 cases of head and neck cancer in our department since 2003, and the agent has been applied in 22 of 32 cases as adjuvant therapy. The primary sites of malignancy included hypopharyngx (7 cases), larynx (6 cases), maxillary sinus (2 cases), oropharynx (2 cases), oral cavity (4 cases), submandibular gland (1 case) and one case in which the primary site was unknown. A regimen of four-week application followed by two-week rest had been used in 6 cases in the first part of this trial. However, a high frequency of blood toxicity was found from the third week, requiring alteration of the protocol. Thus, a new regimen of two-week application followed by one week rest was thereafter used in the other 16 cases. Blood toxicity was found in 66.7% of those cases receiving a four-week application followed by two-week rest regimen. In the 16 cases receiving the two-week application followed by one-week rest regimen, only one case showed grade 2 leucopenia while continuous application for more than eight weeks was possible in 9 cases. Mild macrocytic anemia was found in some of these cases, however none of which required any necessary interruption of the treatment. Side effects other than blood toxicity, such as edema or pigmentation of lower limbs, erythema of skin and diarrhea, were found in the other cases, requiring suspension of the treatment. But the subsequent application was possible after a break or decreasing the dosage. We concluded that the new regimen of two-week application followed by one-week rest is less likely to be interrupted by the side effects and is safer to be used outpatiently, compared with the four-week application followed by two-week rest.

Administration, Oral↗
PubMed2005

[A familial case of summer-type hypersensitivity pneumonitis possibly associated with bird breeder's lung diagnosed by bronchoalveolar lavage fluid].

Case 1: A 32-year-old woman had cough and exertional dyspnea in August 2002, and chest computed tomographic scan revealed diffuse centrilobular nodules. Bronchoalveolar lavage fluid (BALF) showed a high proportion of lymphocytes with a decreased CD 4/CD 8 ratio. Transbronchial lung biopsy (TBLB) specimens showed alveolitis. Summer-type hypersensitivity pneumonitis was diagnosed on the basis of positive findings of anti-Trichosporon antibodies in the serum. Case 2: A 64-year-old man, the father of Case 1, also had cough and exertional dyspnea in August 2003. He had been in close contact with pigeons. Chest computed tomographic scan revealed bilateral map-like ground-glass opacities predominantly in the upper lobes. BALF showed a high proportion of lymphocytes with a decreased CD 4/CD 8 ratio. TBLB specimens showed alveolitis, granuloma and Masson body in the air spaces. Specific IgG and IgA antibodies against Trichosporon asahii, IgA antibodies against Trichosporon mucoides, and IgA antibodies against pigeon dropping extracts were found only in the BALF but not in the serum. Although a positive finding of returning-home provocation test was definitive in diagnosing summer-type hypersensitivity pneumonitis, he was also suspected of having bird fancier's lung.

Adult↗
PubMed2004

Bone marrow cells as an origin of immune-mediated hearing loss.

The MRL/lpr mouse, which is homozygous for the recessive lpr genes and has a mutation in the Fas gene encoding a cell-surface receptor for apoptosis, exhibits severe lymphadenopathy and develops systemic lupus erythematosus (SLE)-like disease. It has recently been reported that this mouse also manifests sensorineural hearing loss (SHL) with cochlear pathology at 20 weeks of age. We examined the effects of reconstituting severe combined immunodeficient (SCID) mice with MRL/lpr bone marrow on the development of SHL. These mice normally develop neither SHL nor cochlear pathology. Immune-mediated SHL and cochlear pathology did, indeed, occur following transfer of MRL/lpr bone marrow into SCID mice. These findings suggest that the development of SHL and cochlear pathology observed in MRL/lpr mice and in SCID mice receiving MRL/lpr bone marrow are the result of bone marrow defects rather than the result of a problem intrinsic to the cochlea.

Animals↗
PubMed2003

Correlation between accelerated presbycusis and decreased immune functions.

The aim of the current study is to analyze the relationship between presbycusis and the immune system, which is affected by pathogenic environments, and to devise a strategy for the prevention of presbycusis using the SAMP1 mouse, an animal model for accelerated senescence that shows both immunological dysfunction and hearing loss caused by the impairment of spiral ganglion cells in the cochlea. When these mice were bred in different pathogenic environments, we found that the development of age-related diseases such as presbycusis was delayed in the mice bred under clean conditions. Prednisolone administration showed no significant prevention of the development of presbycusis in the mice, suggesting that autoimmune mechanisms are not involved in the acceleration of presbycusis. It is conceivable that pathogen-induced infections impose a severe stress on the host, impairing the host's immune functions. A reduction in the number of pathogens may therefore prevent the acceleration of the aging process. These findings suggest that not only the gene backgrounds but also immune functions affect the development of presbycusis in SAMP1 mice. Further studies into the relationship between systemic immune functions and the neuro-generation system may provide additional information about the treatment for age-related diseases.

Aging↗
PubMed2002

Secondary shunt procedure for alaryngeal patients in an outpatient clinic.

The shunt procedure used for laryngectomized patients undergoing secondary tracheo-esophageal (T-E) puncture is inconvenient and causes stress to the patient. In order to overcome these problems we developed a novel surgical T-E shunt technique using the Groningen voice prosthesis that does not require esophagoscopy or general anesthesia and can be performed in an outpatient clinic. In this procedure, a shunt is created using a pair of nasal forceps with the patient seated. An endoscope with biopsy forceps is used to insert the Groningen voice prosthesis. The procedure is usually completed within 20 min after inducing local anesthesia. Neither the technique itself nor the time taken to complete the procedure differed for T-E and tracheo-neoesophageal (reconstructed with flap) shunting. We believe that this procedure is suitable for patients who are afraid of esophagoscopy and/or are not considered suitable candidates for esophagoscopy and repeated general anesthesia. The procedure is also beneficial for both patients and surgeons with regard to its duration and the cost-effectiveness of treatment.

Ambulatory Surgical Procedures↗