Search PubMed⌕ Search

Biomedical subjects

Yasumasa Akagawa

Publications and source records attributed to Yasumasa Akagawa.

14 recordsLinked to original sources
PubMed2006

Decreased tongue pressure reflects symptom of dysphagia.

The tongue plays a key role in oropharyngeal swallowing. It has been reported that maximum isometric tongue pressure decreases with age. The risk for dysphagia resulting from low tongue strength remains unclear. This study was designed to reveal the relationship between tongue pressure and clinical signs of dysphagic tongue movement and cough and to demonstrate the clinical value of tongue pressure measurement in the evaluation of swallowing function. One hundred forty-five institutionalized elderly in five nursing homes participated. Evaluation of physical activity with self-standing up capability and mental condition with Mini Mental Status Examination (MMSE) were recorded. Maximum tongue pressure was determined using a newly developed tongue pressure measurement device. Voluntary tongue movement and signs of dysphagic cough at mealtime were inspected and evaluated by one clinically experienced dentist and speech therapist. The relationship between level of tongue pressure and incidence of cough was evaluated using logistic regression analysis with physical and mental conditions as covariates. Tongue pressure as measured by the newly developed device was significantly related to the voluntary tongue movement and incidence of cough (p < 0.05). The results of this study suggest that tongue pressure measurement reflects clinical signs of dysphagic tongue movement and cough and that measurement of tongue pressure is useful for the bedside evaluation of swallowing.

Aged↗
PubMed2006

Influence of aging and denture use on liquid swallowing in healthy dentulous and edentulous older people.

OBJECTIVES: To clarify the influence of aging and denture use on swallowing in healthy edentulous people aged 75 and older. DESIGN: A cross-sectional research design was used with participants from Hiroshima University Hospital, Hiroshima University, and Hiroshima City. SETTING: Participants were examined in Hiroshima University Hospital, Hiroshima, Japan. PARTICIPANTS: Thirteen edentulous elderly volunteers (7 male, 6 female; aged 75-86, mean age 81.2) and 19 dentulous elderly volunteers (12 male, 7 female; aged 80-87, mean age 81.2) as a control group participated in this study. Participants reported no clinical symptoms relating to dysphagia, neurological impairments, or degenerative diseases. MEASUREMENTS: Participants were asked to swallow a 10-mL barium sulfate solution three times. Edentulous older people were asked to swallow the solution while wearing dentures and with dentures removed. Functional swallowing was recorded on cine-film with a digital subtraction angiography system. Lateral cinefluorography images were obtained from seated subjects. Using a cine-projector, visual images were evaluated qualitatively and quantitatively. RESULTS: No participants exhibited aspiration. The occurrence of laryngeal penetration in the edentulous older people not wearing dentures was the only significant difference (P<.05). CONCLUSION: Only laryngeal penetration differed significantly between edentulous older people not wearing their dentures and dentulous older people.

Administration, Oral↗
PubMed2005

Aspects of swallowing in healthy dentate elderly persons older than 80 years.

BACKGROUND: Although age-related changes resulting in slowing of the swallowing reflex and a decline in the neuromuscular control system have been reported, there have been few reports on swallowing function in dentate elderly persons. The purpose of this study was to clarify the primary influence of aging on swallowing in healthy dentate elderly persons older than 80 years who have more than 20 teeth. METHODS: Dentate elderly persons (12 male, 7 female; mean age: 81.2 years) and dentate young participants (9 male, 5 female; mean age: 26.8 years) as a control group participated voluntarily. Participants reported no clinical symptoms relating to dysphagia, neurologic impairments, or degenerative diseases, and were asked to swallow 10 ml of barium sulfate solution (10% w/v) three times. Functional swallowing was recorded on 35 mm cinefilm at 30 frames per second with a digital subtraction angiography system. Lateral images of cinefluorography of seated participants' mouth, pharynx, and larynx were obtained. Visual image analysis for qualitative and quantitative evaluation was made with a cine projector. RESULTS: No participants exhibited aspiration during three trials. Occurrence and frequencies of piecemeal deglutition, premature loss of liquid, oral and pharyngeal residues, and laryngeal penetration were significantly greater in dentate elderly persons (p <.05) than in the dentate young participants. Oral transit time, pharyngeal delay time, and pharyngeal transit time in dentate elderly persons were prolonged significantly compared with those in dentate young participants (p <.01). CONCLUSION: Physiological swallowing functions deteriorate even in healthy dentate elderly persons. This deterioration may be explained primarily by the influence of aging on swallowing.

Adult↗
PubMed2005

New surface modification of titanium implant with phospho-amino acid.

The purpose of this study was to investigate a new biochemical surface modification technique for titanium implants using phospho-amino acid. Pure titanium disks were pretreated with 10 N HCl and ultrapure water at room temperature for 30 minutes respectively. Then these disks were modified with either L-threonine (Thr) or O-phospho-L-threonine (P-Thr) at 37 degrees C for 12 hours. X-ray photoelectron spectroscopy (XPS) chemically analyzed the modified surfaces. It was revealed that the N 1s peak which originated from Thr was not detected in the wide-scan spectrum of Thr-modified surface, whereas three peaks of N 1s, P 2s, and P 2p which originated from P-Thr were detected in the wide-scan spectrum of P-Thr-modified surface. Moreover, the P 2p peak of P-Thr which reacted with the surface significantly shifted to a lower binding energy (p < 0.05). Based on the results of this study, it was concluded that P-Thr chemically bonded to the titanium surface treated with HCl.

Dental Bonding↗
PubMed2005

Eight-year mortality associated with dental occlusion and denture use in community-dwelling elderly persons.

OBJECTIVE: To evaluate the influence of dental occlusion, with or without the use of dentures, on mortality in community-dwelling elderly persons. SUBJECTS: A total of 1030 randomly selected healthy independent elderly aged 65 and over were surveyed in 1995. For the study reported here, subjects were classified into three groups according to the presence or absence of maxillo-mandibular tooth contacts. Subjects with no maxillo-mandibular tooth contacts were further subdivided into those with and without dentures. METHODS: Data on mortality were obtained from Kure City Council in September 2003. Cox regression models were used in analysing the risk for death with gender and age as covariates. RESULTS: Individuals whose teeth had contact in at least the bilateral premolar regions at baseline had 0.78 times (95% CI: 0.60-0.99) smaller risk for death during the succeeding 8 years than those who had no occlusion. Among those who had no occlusion with their own teeth, the risk for mortality among denture non-users was 1.52 times (95% CI: 1.25-1.83) higher than the risk for denture users. CONCLUSION: These results may support the view that, in the elderly; poor dental occlusion is associated with an increased risk for mortality and that, in the edentulous, the use of dentures is associated with a decreased risk for mortality.

Age Factors↗
PubMed2002

Oral care reduces pneumonia in older patients in nursing homes.

OBJECTIVES: Aspiration of oral secretions and their bacteria is increasingly being recognized as an important factor in pneumonia. We investigated whether oral care lowers the frequency of pneumonia in institutionalized older people. DESIGN: Survey. SETTING: Eleven nursing homes in Japan. PARTICIPANTS: Four hundred seventeen patients randomly assigned to an oral care group or a no oral care group. INTERVENTION: Nurses or caregivers cleaned the patients' teeth by toothbrush after each meal. Swabbing with povidone iodine was additionally used in some cases. Dentists or dental hygienists provided professional care once a week. MEASUREMENTS: Pneumonia, febrile days, death from pneumonia, activities of daily living, and cognitive functions. RESULTS: During follow-up, pneumonia, febrile days, and death from pneumonia decreased significantly in patients with oral care. Oral care was beneficial in edentate and dentate patients. Activities of daily living and cognitive functions showed a tendency to improve with oral care. CONCLUSION: We suggest that oral care may be useful in preventing pneumonia in older patients in nursing homes.

Age Factors↗
PubMed2002

Carbachol-induced fluid movement through methazolamide-sensitive bicarbonate production in rat parotid intralobular ducts: quantitative analysis of fluorescence images using fluorescent dye sulforhodamine under a confocal laser scanning microscope.

Fluid secretion is observed at the openings of ducts in the exocrine gland. It remains unclear whether the ducts are involved in fluid secretion in the salivary glands. In the present study, we investigated the exclusion of fluorescent dye from the duct lumen by carbachol (CCh) in isolated parotid intralobular duct segments to clarify the ability of the ducts for the fluid secretion. When the membrane-impermeable fluorescent dye, sulforhodamine, was added to the superfused extracellular solution, quantitative fluorescence images of the duct lumen were obtained under the optical sectioning at the level of the duct lumen using a confocal laser scanning microscope. CCh decreased the fluorescent intensity in the duct lumen during the superfusion of the fluorescent dye, and CCh flushed out small viscous substances stained with the fluorescent dye from isolated duct lumen, suggesting that CCh might induce fluid secretion in the duct, leading to the clearance of the dye and small stained clumps from the duct lumen. CCh-induced clearance of the fluorescent dye was divided into two phases by the sensitivity to external Ca2+ and methazolamide, an inhibitor for carbonic anhydrase. The initial phase was insensitive to these, and the subsequent late phase was sensitive to these. A major portion in the late phase was inhibited by removal of bicarbonate in the superfusion solution and DPC, but not low concentration of external Cl-, bumetanide or DIDS, suggesting that methazolamide-sensitive production of HCO3-, but not the Cl- uptake mechanism, might contribute to the CCh-induced clearance of the dye from the duct lumen. These results represent the first measurements of fluid movement in isolated duct segments, and suggest that carbachol might evoke fluid secretion possibly through Ca2+-activated, DPC-sensitive anion channels with HCO3- secretion in the rat parotid intralobular ducts.

Animals↗
PubMedDate not supplied

In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) affects tooth development in rhesus monkeys.

We thought to validate the current tolerable daily intake (TDI) value for dioxin (4 pg/kg) in Japan. Pregnant rhesus monkeys received an initial dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 0, 30, or 300 ng/kg subcutaneously) on day 20 of gestation; the dams received additional injection of 5% of the initial dose every 30 days until day 90 after delivery. The teeth of stillborn, postnatally dead, and surviving offspring (now approximately 4 years old) were evaluated. None of the offspring in the 0 and 30 ng/kg groups (n=17 and 15, respectively) had tooth abnormalities, whereas 10 of 17 in the 300 ng/kg had them. These findings suggest the lowest-observed adverse-effect level (LOAEL) for TCDD in the rhesus monkey is between 30 and 300 ng/kg, and probably is close to that for rodents (86 ng/kg) on which the current TDI was based. It is reasonable to conclude that the current TDI needs no immediate modification.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

A novel handy probe for tongue pressure measurement.

PURPOSE: The purpose of this study was to develop a handy probe to measure tongue pressure without fear of radiation or infection. MATERIALS AND METHODS: A probe was assembled using a small balloon, a stainless pipe, and a 1-mL disposable tuberculin-test syringe cylinder. The probe was pressurized to set the balloon diameter at approximately 18 mm. Forty-one subjects (16 men and 25 women, 24 to 84 years of age) participated. To record maximal voluntary tongue pressure, the subjects were asked to compress the balloon onto their palates as strongly as possible. To record deglutitious tongue pressure, 5 mL of water was measured and administered with a scaled 10-mL syringe and swallowed with the balloon in the mouth. Both types of pressure were recorded three times at 1-minute intervals. Peak values of each record were measured. RESULTS: Individuals varied from 10 to 41 kPa in the maximal voluntary trial and 3 to 27 kPa in the deglutitious trial, with 5 and 7 kPa mean intraindividual ranges of reproducibility, respectively. A negative correlation to age was found for both types of pressure. No gender differences or effects of dentition were found. CONCLUSION: A disposable handy probe for measuring tongue pressure was developed and tested for clinical use. Despite the limited information acquired, we could see some quantitative aspects of tongue function conveniently and safely.

Adult↗
PubMedDate not supplied

Cytotoxicity of antimicrobial tissue conditioners containing silver-zeolite.

PURPOSE: The purpose of this study was to determine the effects of incorporating antimicrobial silver-zeolite on the in vitro cytotoxicities of five tissue conditioners against the living dermal model, which consisted of normal human dermal fibroblasts in a collagen lattice. MATERIALS AND METHODS: Samples of each tissue conditioner containing silver-zeolite (2 wt% and 5 wt%) were prepared; samples without silver-zeolite were used as a control. Cytotoxicity of each sample against the living dermal model was evaluated by cell viability with MTT assay. RESULTS: Cell viabilities for Visco-Gel, GC Soft-Liner, FITT, and SR-Ivoseal decreased with increasing silver-zeolite content. Cell viability for Shofu Tissue Conditioner showed no significant difference with degree of silver-zeolite incorporation and had higher values than other tissue conditioners. CONCLUSION: Individual compounds eluted from tissue conditioners and silver ions released from silver-zeolite might cause such cytotoxicity. The results suggest that Shofu Tissue Conditioner is a possible candidate for a novel antimicrobial tissue conditioner containing silver-zeolite because it showed the highest cell viability and the smallest influence of incorporating silver-zeolite.

Acrylic Resins↗
PubMedDate not supplied

Influence of mental status on removable prosthesis compliance in institutionalized elderly persons.

PURPOSE: It is well-recognized that many institutionalized elderly persons with dementia do not wear dentures. The objective of this study was to evaluate the current status of denture use among elderly patients with dementia, in association with degree of mental impairment, to provide information relating to a decision-making process for optimal denture treatment. MATERIALS AND METHODS: From August 2001 to December 2002, 101 hospitalized elderly persons in a geriatric hospital dental clinic received removable denture treatment by two certified prosthodontists. Prior to denture treatment, patient mental status was evaluated using the Mini Mental Status Examination (MMSE). Basic activities of daily living, including mobility, feeding, toilet use, dressing, and bathing, were also evaluated. Denture acceptance was determined 6 months after denture delivery. RESULTS: Eight patients were excluded; 73 patients had accepted their dentures and 20 had not 6 months after denture delivery. The mean MMSE score for patients who did not accept denture delivery (11.7+/-7.0) was significantly lower than that of those who did accept and wear their dentures (16.0+/-6.8). CONCLUSION: The cognitive status of institutionalized elderly persons with dementia should be a criterion for clinical decision making relating to denture treatment.

Activities of Daily Living↗