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Biomedical subjects

H Nakagaki

Publications and source records attributed to H Nakagaki.

At least 19 recordsLinked to original sources
PubMed2001

Fluoride concentrations at and near the neonatal line in human deciduous tooth enamel obtained from a naturally fluoridated and a non-fluoridated area.

This study sought to obtain a precise profile of fluoride concentrations at and near the neonatal line in deciduous incisors and canines from the naturally fluoridated area (1.0--1.3 parts/10(6) F in drinking water) of West Hartlepool and the non-fluoridated area (less than 0.1 parts/10(6) F in drinking water) of Leeds in England. An abrasive microsampling method was used to determine the distribution of fluoride and phosphorus concentrations. The profile of fluoride concentrations in 100-microm layers before and after the neonatal line, that is, in the prenatal and postnatal enamel, were significantly higher in teeth from the fluoridated than non-fluoridated areas. It was concluded that the fact that the fluoride concentrations were about the same prenatally and postnatally in deciduous enamel obtained from the fluoridated and non-fluoridated areas indicates that fluoride enters the prenatal deciduous enamel and that it is transferred through the placenta.

Calcium↗
PubMed2000

Magnesium and fluoride distribution in human cementum with age.

Sixty-two human teeth, obtained from subjects aged 11 to 80 years, were used to determine the magnesium and fluoride concentration and distribution with age in human cementum. Transverse sections were prepared from the root region of teeth. Samples, each 30 microm thick, were abraded in sequence from the cementum surface and the cemento-dentine junction by an abrasive micro-sampling technique. Magnesium concentrations were lower in the cementum surface, and increased towards the cemento-dentine junction (CDJ), while fluoride concentrations were higher in cementum surfaces and tended to decrease towards CDJ. Fluoride distribution patterns were similar to that reported earlier while average fluoride concentration increased with age, however, either no change or decreasing tendencies were observed with magnesium.

Adolescent↗
PubMed2000

Fluoride and magnesium concentrations in human dental calculus obtained from Japanese and Chinese patients.

Calculus deposited on a total of 68 permanent teeth from patients 30-60 years old from Nagoya in Japan and Beijing in China was investigated. An abrasive microsampling method was used to examine the fluoride (F) and magnesium (Mg) distribution, using a fluoride ion-specific electrode and atomic absorption spectrophotometry, respectively. F concentrations decreased from the surface towards the interior of the calculus. Mg concentrations, however, gradually rose towards the innermost surface adjacent to the tooth. In all parts of the depth profiles, the average concentrations of both magnesium and fluoride were higher in the Japanese than in the Chinese calculus. Towards the inner surface of the calculus, F and Mg concentrations were also much higher in the Japanese than in the Chinese group. A greater intake of sea foods and greater use of fluoride dentifrices are possible reasons for the higher F and Mg concentrations in the Japanese individuals.

Adult↗
PubMed2000

Oral glucose retention, saliva viscosity and flow rate in 5-year-old children.

There are significant differences of glucose retention in site-specificity and individuals. Sixty-two 5-year-old nursery schoolchildren participated in this study on the relation between the viscosity of saliva and flow rate and glucose retention. Each child was instructed to rinse his/her mouth with a glucose solution (0.5 M, 5 ml) and then to spit out. Three minutes after rinsing, glucose retention was determined. Resting saliva was collected by a natural outflow method, then the flow rate was determined. A rotational viscometer was used to determine the viscosity. Glucose retention and flow rate were correlated at the left maxillary primary molars, and glucose retention and viscosity were correlated at the maxillary central primary incisors. It was concluded that glucose retention after glucose mouth rinsing was site-specific, and that glucose retention and the index of decayed, missing and filled primary teeth (dmft) were slightly correlated with the salivary viscosity and flow rate.

Analysis of Variance↗
PubMed2000

[Work load analysis for oral care in special nursing homes].

The work load analysis for oral care in special nursing homes. Dental hygienists undertook oral care of 100 person who were confined to special nursing homes in Aichi prefecture, Japan. The time required, the physical load, the psychological burden were analysed. The results were summarized as follows; 1) Oral care by dental hygienist was incorporated as one of the 59 care tasks given in special nursing. 2) The working time for required oral care was 25.7 minutes per resident on an average. 3) In general, speaking to the elderly, recording on an assessment card, and observing conditions were undertaken most frequently. In oral care, tooth cleaning, gargling, cleaning of dentures, wiping of the mouth and advising those caring for the elderly, was performed most frequently. 4) In general, time taken for advising those caring for the elderly, report to the home dentistry, advising the elderly, recording, and evaluation was most common. In oral care by a dental hygienist, tooth cleaning, cleaning of the dentures, cleaning the mouth, gargling, prevention of dryness of the mouth were performed most frequently. 5) In physical activity, raising the person, moving him from the wheelchair to the bed and helping him to lie down were most frequent. In oral care by a dental hygienist, wiping the mouth, inserting dentures, tooth cleaning, cleaning the mouth and removing dentures were most common. 6) The psychological burden when lifting the person, moving him from the bed to the wheelchair and helping him to lie down was the greatest. In burden involving oral care by a dental hygienist, tooth cleaning, removing dentures, inserting dentures and cleaning the mouth were the greatest.

Homes for the Aged↗
PubMed2000

[An oral health scoring system for promoting 8020 achievement in residents].

The present study was undertaken to develop a self-scoring system which can be used by a resident to check lifestyle. The oral health scoring system which we used in Tobishima village, Aichi-ken, was named SAWAYAKA score. A total of 777 subjects were examined. The subjects responded to a questionnaire regarding their past individual lifestyles and dietary habits. Oral health conditions were also examined by dentists. The odds ratio and 95% confidence interval were calculated both from retained tooth numbers and the questionnaire. Questions with significant odds ratio were selected and the partial regression coefficients of quantification II method by Hayashi were calculated. The results are as follows; 1) Eleven questions showed a significant odds ratio between retained tooth numbers and past lifestyle and dietary habits. The questions involved the frequency of snack intake, tooth brushing frequency, having own tooth brush, smoking, drinking, having a hobby, having a family dentist, consulting a dentist before a problem got serious, gum bleeding, swollen gums and toothache caused by sensitivity to cold water. 2) The eleven items were analysed by using Hayashi's quantification II method. 3) The results showed that unswollen gums affected the retention of teeth by the range of 1.240. Toothache caused by sensitivity to cold water affected the retention of teeth by the range of 0.765. Having a hobby affected the retention of teeth by the range of 0.691. 4) The "SAWAYAKA" score was used to select important items, excluding drinking. 5) When results were analysed with the SAWAYAKA score, an average of 9.6 was obtained. It was concluded that the scoring list could be used for checking resident's lifestyles, and for promoting the preservation of more than 20 teeth at the age of 80.

Adult↗
PubMed1998

Fluoride profiles of perikymata in enamel surfaces of human premolars.

Twenty-five premolars (from Nagoya, Japan < 0.1 parts/10(-6)F in drinking water) were sampled to determine the fluoride content in imbrication lines of Retzius between the grooves and ridges of perikymata on the enamel surface. Eight small windows were formed on each surface in groove and ridge regions using an etched microsampling technique. By using a regression curve, y = ax(-b), fluoride concentrations were compared at depths of 1, 3, 5, 10, 20, 30 and 50 microm in the perikymata regions. Fluoride concentrations increased gradually from the age of 10 to 12 years on the premolar surfaces, but were significantly higher in 12-year-olds or older (erupted teeth) than in 10-year-olds or younger (unerupted teeth). No obvious difference in fluoride concentrations was found between males and females. In the outermost enamel ( < 5 microm depth), fluoride concentrations were significantly higher in the grooves than the ridges of the perikymata. Comparison of the exponential regression coefficients (-b) of the fluoride profiles showed a significant difference between the grooves and ridges. It was concluded that fluoride concentrations and profiles were higher in grooves than in ridges of perikymata, probably because they are naturally porous and are stagnation areas attracting dental plaque.

Acid Etching, Dental↗
PubMed1998

Expression of an orphan nuclear receptor DAX-1 in human pituitary adenomas.

OBJECTIVES: An orphan nuclear receptor, DAX-1, is known to be involved in the development and differentiation of anterior pituitary cells. The present study aimed to examine 1) whether DAX-1 is expressed in human pituitary adenomas, and 2) if it is expressed, what types of adenoma express the factor. MATERIALS AND METHODS: Adenoma tissues examined included 18 clinically non-functioning adenomas, 14 GH-secreting adenomas and 7 PRL-secreting adenomas. The expression of the following genes were tested by reverse transcription-polymerase chain reaction (RT-PCR): DAX-1, Adrenal-4-binding protein/steroidogenic factor-1 (Ad4BP/SF-1), Pit-1, LH beta, FSH beta, gonadotrophin-releasing hormone receptor (GnRH-R), GH, PRL, and TSH beta, as well as beta-actin as a control. RESULTS: Eleven clinically non-functioning adenomas expressed DAX-1, 10 of which also expressed Ad4BP/SF-1. Nine out of the 11 DAX-1 expressing adenomas also expressed LH beta, FSH beta and GnRH-R as well, indicating that these adenomas possessed gonadotrophic properties. Nine clinically non-functioning adenomas expressed Pit-1 as well as GH, PRL and/or TSH beta, thus having somatomammotrophic or thyrotrophic properties, 3 of which overlapped with the above DAX-1-expressing adenomas. One non-functioning adenoma expressed Ad4BP/SF1 and FSH beta but not DAX-1, and another one expressed DAX-1 and Ad4BP/SF-1 with PRL. On the other hand, all GH-secreting and PRL-secreting adenomas expressed Pit-1 and GH and/or PRL, but neither DAX-1 nor Ad4BP/SF-1. CONCLUSIONS: The results shown here indicate that DAX-1 is expressed in the majority of human pituitary adenomas of gonadotrophic origin in parallel with Adrenal-4-binding protein/steroidogenic factor-1.

Adenoma↗
PubMed1997

A method for determining the distribution of fluoride, calcium and phosphorus in human dental plaque and the effect of a single in vivo fluoride rinse.

A new sampling method, capable of sampling plaque from its surface to its interior for quantitative studies, was modified to meet some of the requirements for the determination of the fluoride and mineral (Ca and P) profiles within dental plaque formed in vivo. Plaque samples were repeatedly collected from the same individual, using special devices, before a single fluoride rinse (900 parts/10(6) fluoride) and 10 min and 24 hr after rinse. The method allowed examination of fluoride, calcium and phosphorus distribution along the entire thickness of plaque. Fluoride content significantly increased throughout the sample 10 min after rinsing, indicating the fluoride had rapidly penetrated into the plaque. Although the elevated fluoride concentrations diminished almost to baseline with 24 hr, a high correlation was found between fluoride and minerals in each plaque fraction. It is concluded that this technique will be useful for evaluating the fluoride and mineral behaviour in the saliva/plaque and plaque/enamel interfaces, and the anti caries efficacy of fluoride applications.

Calcium↗
PubMed1997

Fluoride profiles in the cementum and root dentine of human permanent anterior teeth extracted from adult residents in a naturally fluoridated and a non-fluoridated area.

OBJECTIVES: To determine the effect of water fluoride concentration on the fluoride profile across the entire thickness of the cementum and root dentine of human permanent anterior teeth in adults. SUBJECTS: Twenty-eight human permanent anterior teeth from individuals aged from 30 to over 60 years were studied. SETTING: Teeth were obtained from a natural high-fluoride area (West Hartle-pool, UK; 1.0-1.3 ppm F in drinking water, WHP) and the other from a non-fluoridated naturally low fluoride area (Leeds, UK; 0.1 ppm F in drinking water, LDS). DESIGN: Cementum and root dentine were sampled using an abrasive micro-sampling technique from the cementum surface to the pulpal surface of root dentine. RESULTS: Fluoride concentration was higher in tooth roots (the cementum and dentine) taken from the naturally fluoridated area (WHP) than from the non-fluoridated area (LDS). Age and average fluoride concentration showed a positive correlation in WHP dentine, middle region of the root (r = 0.78, P < 0.001) and in the apical region of the root (r = 0.61, P < 0.05). WHP cementum had the strongest fluoride concentration correlation with age in the cervical region of the root (r = 0.67, P < 0.01). An analysis of variance (ANOVA) showed that the area (water fluoride content), age and number of years lived in the area combined with total age were significant. CONCLUSIONS: The fluoride content of cementum and root dentine in adult residents is related to fluoride content in drinking water.

Adult↗
PubMed1997

A method for the quantitative site-specific study of the biochemistry within dental plaque biofilms formed in vivo.

The study of plaque biofilms in the oral cavity is difficult as plaque removal inevitably disrupts biofilm integrity precluding kinetic studies involving the penetration of components and metabolism of substrates in situ. A method is described here in which plaque is formed in vivo under normal (or experimental) conditions using a collection device which can be removed from the mouth after a specified time without physical disturbance to the plaque biofilm, permitting site-specific analysis or exposure of the undisturbed plaque to experimental conditions in vitro. Microbiological analysis revealed plaque flora which was similar to that reported from many natural sources. Analytical data can be related to plaque volume rather than weight. Using this device, plaque fluoride concentrations have been shown to vary with plaque depth and in vitro short-term exposure to radiolabelled components may be carried out, permitting important conclusions to be drawn regarding the site-specific composition and dynamics of dental plaque.

Bacterial Adhesion↗
PubMed1997

The cessation of fluoridated water administration and the fluoride distribution profiles in rat molar cementum.

The aim of this work was to obtain further information about the origin of fluoride profiles in cementum. Fluoride was administered to rats at varying doses (0.50, 100 ppm F in drinking water) and for different durations (4, 13 and 25 weeks). Fluoride distribution across the full thickness of molar cementum in rats was measured by means of an abrasive micro-sampling technique. The average fluoride concentrations in cementum increased significantly with increasing dose and duration of fluoride administration. The relative reduction of the average fluoride concentrations after cessation of fluoride administration was 94.2-36.5% at 50 ppm F and 62.2-49.2% at 100 ppm F in the outer layers (1-60 microns) and 91.5-24.1% at 50 ppm F and 74.1-7.6% at 100 ppm F in the middle (61-120 microns) layers of the cementum, respectively. The reduction rates were more closely related to the time intervals following cessation rather than fluoride concentrations in drinking water or specificity within the cementum. Two factors which may influence this are new cementum formation after withdrawal of fluoride and some fluoride release from cementum surfaces when the fluoride supply stopped. It was concluded that the cessation of fluoride administration reduced the fluoride concentration on the outer layers of cementum differing from bone where reduction occurs across the entire thickness.

Analysis of Variance↗
PubMed1996

In vivo fluoride profiles at different sites of buccal and lingual enamel surfaces obtained by enamel biopsy of human maxillary first permanent molars in young adults.

Twenty male volunteers, average age 24 years, participated in this study. Specimens were obtained by enamel biopsy using 5 microliters of 0.5 M HClO4 for 30 s. Using a regression curve, comparisons of fluoride concentrations were made at different depths. The fluoride concentrations (mean +/- SE) at a depth of 5 microns were highest in the distobuccal (1698 +/- 136), high in the mesiobuccal (1343 +/- 122), low in the distolingual (1119 +/- 107), and lowest in the mesiolingual sites (819 +/- 78). Of the interior enamels (> or = 10 microns in depth), the distobuccal site (1330 +/- 88 parts/10(6) F at 10 microns) had a higher-concentration than all other sites. The fluoride profiles were steepest to shallowest in the order: distobuccal, mesiobuccal, distolingual and mesiolingual. There were no correlations between the enamel fluoride concentrations and the fluoride concentration in parotid saliva. It was concluded that in vivo fluoride profiles of maxillary first molars reflect the wear of the tooth surface with age and the condition of dental plaque deposition, and, to some extent, the site-specific distribution of saliva between buccal and lingual surfaces.

Adult↗
PubMed1996

Follicle stimulating hormone-beta subunit gene is expressed in parallel with a transcription factor Ad4BP/SF-1 in human pituitary adenomas.

OBJECTIVES: A transcription factor Ad4BP/SF-1 is implicated in the differentiation of gonadotrophs in the pituitary gland, but it is not known whether human pituitary cells express this factor. The present study aimed to disclose (1) whether human pituitary adenomas express Ad4BP/SF-1, and (2) if this is the case, what kinds of adenoma express the factor. MATERIAL: Total RNA was extracted from 23 pituitary adenomas obtained by transsphenoidal surgery, and subjected to Northern blot analyses using cDNAs of bovine Ad4BP/SF-1, porcine FSH-beta, LH-beta and glycoprotein hormone-alpha (GPH-alpha) subunts as radiolabelled probes. These adenomas included 13 clinically non-functioning adenomas, 1 GH/PRL-producing adenoma, 6 GH-producing adenomas, 2 PRL-producing adenomas and 1 ACTH-producing adenoma. RESULTS: The expression of Ad4BP/SF-1 exactly coincided with the expression of FSH-beta. Thus 5 out of 13 clinically non-functioning adenomas expressed Ad4BP/SF-1 and only these 5 adenomas expressed FSH-beta. Interestingly, only one of the GH-producing adenomas also expressed Ad4BP/SF-1 as well as FSH-beta. GPH-alpha was expressed in 4 non-functioning adenomas and 2 hormonally functioning adenomas, but did not necessarily coincide with Ad4BP/SF-1 expression. None of the 23 adenomas we tested expressed LH-beta, probably because LH-beta-producing adenomas are rather rare. CONCLUSIONS: The expression of FSH-beta was parallel with Ad4BP/SF-1 expression, indicating that the expression of Ad4BP/SF-1 is restricted to cells derived from gonadotroph lineages in human pituitary adenomas.

Adenoma↗
PubMed1996

Fluoride distribution in human dental calculus obtained from different sites on the tooth surface.

We examined the site specificity of fluoride (F) distribution in human dental calculus. Teeth with supra- and subgingival calculus were obtained from patients who resided in non-fluoridated areas in Japan and China. Sequential layers of the dental calculus (30 microns thick) were abraded by an abrasive micro-sampling technique and fluoride and phosphorus in the powdered samples were analyzed. Fluoride concentrations were highest in the outer, lowest in the middle and intermediate in the inner layers of dental calculus in general. In the outermost layers fluoride concentrations were highest in calculus found near the tooth cervix both in supra- and subgingival calculus. Fluoride concentrations decreased markedly toward the apical region in subgingival calculus, while it did not change toward the incisal or occlusal region in supragingival calculus. In the inner layers, fluoride concentrations in both supra- and subgingival calculus were not affected by position on the teeth. Fluoride concentrations in subgingival calculus near the apex were lower than in supragingival calculus near the incisal or occlusal region. It was concluded that the fluoride concentrations differ in different regions of dental calculus, probably due to their different mechanisms of formation.

Calcium Phosphates↗
PubMed1996

Fluoride concentrations and distribution in premolars of children from low and optimal fluoride areas.

We have compared the fluoride (F) concentrations from the enamel surface to the dentino-enamel junction (DEJ), and through dentine to the dentino-pulpal junction (DPJ) in premolars extracted from school children in Chemnitz (former Karl-Marx-Stadt), Germany (F: 1.0 ppm in the water supply), Erfurt, Germany (F: 0.2 ppm in the water supply) and Nagoya, Japan (F: 0.1 ppm in the water supply). In teeth from children in Cheminitz, Erfurt and Nagoya, the profiles of F distribution using an abrasive microsampling technique revealed high F concentrations in the enamel surface, with a substantial decrease towards a plateau in the interior. In dentine the F concentrations were higher than in enamel, and also decreased to a plateau from the DEJ, thereafter increasing considerably towards the DPJ. F concentrations at any depth in the enamel and dentine of teeth from Chemnitz were 2-3 times higher than those in Erfurt and Nagoya. There was no significant difference in F concentrations or distributions between Erfurt and Nagoya. Close to the DEJ in both enamel and dentine as well as the enamel surface and the DPJ side of dentine, higher F concentrations were observed in Chemnitz compared with Erfurt and Nagoya.

Adolescent↗
PubMed1996

Cyclic Cushing's disease in long-term remission with a daily low dose of bromocriptine.

A 56-year-old male patient with cyclic Cushing's disease remained in a state of remission for more than one year with a relatively low dose of bromocriptine (2.5-3.75 mg/day). It has been reported that bromocriptine treatment for cyclic Cushing's disease induces only a transient remission; in the most effective cases, a relatively high dose (40 mg/day) was necessary. In the hypercortisolemic state, plasma adrenocorticotropic hormone (ACTH) and serum cortisol were not suppressed by dexamethasone and did not respond to corticotropin-releasing factor (CRF). An antehypophysectomy was not effective, even though the resected tissue contained ACTH-positive microadenomas. The present observations thus indicate the effectiveness of bromocriptine for some patients with this rare disorder.

Adenoma↗