Biomedical subjects

Y Takaesu

Publications and source records attributed to Y Takaesu.

At least 37 records · Page 2Linked to original sources

PubMed1994

pH response of human dental plaque to chewing gum supplemented with low molecular chitosan.

The effects of low molecular chitosan (LMCS) on pH responses of human dental plaque following exposure to fermentable carbohydrates were investigated by an ion-sensitive field-effect transistor electrode system. After the plaque pH values were minimized by direct application of 5% glucose solution or consumption of sugared caramel, the subjects started chewing the test gums containing 0 (control), 1 or 3% (w/w) LMCS for three minutes. The pH response was monitored until it recovered to over pH5.5. In the case of the glucose solution, chewing 3% LMCS gum caused significantly more rapid pH recovery toward the resting level than did the control gum. Initial pH rising rate during gum chewing was faster with either of the two LMCS gums than with the control gum. In the case of caramel, additional effects of LMCS were observed numerically as LMCS content increased. The findings indicated that LMCS had a potential to promote recovery of plaque pH after acidogenic challenge and to maintain the plaque pH around neutrality.

Adult↗

PubMed1994

Oral health status related to subgingival bacterial flora and sex hormones in saliva during pregnancy.

The purpose of this study was to investigate oral health status in relation to subgingival microflora and sex hormone concentrations in saliva during pregnancy. Oral health examinations were performed on 39 subjects: of 19 pregnant women (mean age 28.5), and 8 women in the fifth post-partum month (mean age 27.1), and 12 non-pregnant women (mean age 22.9). Periodontal conditions of bleeding on probing, redness, swelling, and probing depth were examined. Subgingival microbial compositions were examined with several selective media. Concentrations of estradiol and progesterone in saliva were determined during pregnancy and the first post-partum month. From the third to the fifth month of pregnancy, the number of gingival sites where probing caused bleeding increased concomitantly with increasing percentages of Prevotella intermedia. The number of gingival sites with redness and swelling increased in the fourth and seventh months of pregnancy and decreased in the last month of pregnancy to the level of the second month. The gingival inflammatory signs, however, tended to increase in the first post-partum month. The probing depth of gingiva gradually increased during pregnancy and the first post-partum month. Percentage of P. intermedia increased in the fourth month of pregnancy with increasing of hormones in saliva. The concentrations of hormones in saliva attained peaks in the ninth month of pregnancy. Thereafter, proportion of P. intermedia decreased. As a further step, these pregnant women were divided into three groups on the bases of percentages and detectable rates of P. intermedia. Gingival inflammation was more extensive in the high group subjects in which more than 15% P. intermedia in total CFU was detected; its severity also tended to increase.

Actinomyces↗

PubMed1993

[A study on acute organophosphorus poisoning--changes in the activity and isoenzyme patterns of serum cholinesterase in human poisoning].

Various organophosphorus compounds with low acute toxicity levels are widely used as insecticides. Human acute poisoning by organophosphates has often occurred accidentally. We determined the activity and isoenzyme patterns of serum cholinesterase (ChE) obtained from 13 human patients who attempted suicide with various organophosphates, i.e. Fenitrothion, Malathion, Isoxathion, Pyridaphenthion and Trichlorfon, and studied on the changes in the activity and isoenzyme patterns of serum ChE after ingestion. The following results were obtained. 1) Twenty ChE isoenzyme bands from normal human serum were detected by electrophoretic separation on polyacrylamide gradient gel. The main bands in the ChE isoenzyme pattern in normal serum were bands 4 and 5 which had the highest activity of acetylcholinesterase (AChE) with a molecular weight of 600,000-800,000, and bands 7, 12, 14, 17 and 18. 2) Inhibition of serum ChE activity was more severe as the amount ingested increased in patients who took Fenitrothion and Malathion. Reactivation of serum ChE activity was very slow in patients treated with PAM (2-pyridine aldoxime methiodide) in the late stage of ingestion or whose symptoms reappeared. 3) There were no differences in the patterns of serum ChE isoenzyme by organophosphorus compound. Band 7 disappeared in the serum ChE isoenzyme of almost every patient, and bands 12, 18, 14 and 17 of the serum ChE isoenzyme disappeared successively with the decline of serum ChE activity. Only band 5 of the isoenzyme remained in cases who had serum ChE activity lower than 5% of normal. 4) All 13 patients were treated with PAM and atropine immediately after being admitted to hospitals. We could not clearly determine the efficacy of PAM on reactivation of serum ChE activity and isoenzyme, because it was impossible in human poisoning to compare PAM efficacy with no treatment and with pre- and post-PAM treatment. 5) The activity and isoenzyme patterns of serum ChE recovered rapidly after combined hemoperfusion and hemodialysis treatment (HP-HD treatment) of the patients poisoned with Malathion. But HP-HD treatment had no effect on poisoning by Fenitrothion and Isoxathion. These findings demonstrated the changes in the activity and isoenzyme pattern of serum ChE in patients poisoned with several organophosphates after PAM and HP-HD treatment.

Acute Disease↗

PubMed1993

[Cognitive ability regarding dental plaque and oral bacteria in schoolchildren: results from an interview research of primary and junior high school students].

The cognitive abilities regarding dental health terms, especially of dental plaque, were examined among schoolchildren. An interview of 112 primary and junior high school students was performed to test knowledge of the cause of dental caries and meaning of some dental health terms. Results indicate that most schoolchildren had difficulty understanding the correct meaning of dental plaque and oral bacteria. Some of them did not recognize the existence of oral bacteria, much less dental plaque. From these results, factors which may interfere with correct understanding of dental plaque were examined. Among them, inaccurate knowledge of existence of oral bacteria appears to be an important factor.

Adolescent↗

PubMed1993

Prevalence of root caries in a Japanese adult population aged 20-59 years.

The purpose of the present study was to investigate the prevalence of root caries in an adult population in Japan. A total of 770 company employees aged 20-59 were examined in 1990. The subjects were all dentate and had 27.2 present teeth on the average. The proportion of gingival recession in this population ranged from 20.1% for the 20-29 year old group to 75.2% for the 50-59 year old group, with an average of 44.0%. In the present study, 3.2% of the subjects showed one or more active root caries. The prevalence of active root caries ranged from 0.4% at age 20-29 to 7.1% at age 50-59. The proportion of persons with active root caries and/or root fillings ranged from 1.3% at age 20-29 to 36.3% at age 50-59. The percentage of subjects with active and/or inactive caries and/or root fillings varied from 3.1% at age 20-29 to 43.4% at age 50-59. The prevalence of active root caries in the subjects at risk (with gingival recession) was 7.4% on the average and ranged from 2.2% at age 20-29 to 9.4% at age 50-59. The percentage of persons with active root caries and/or root fillings in the subjects at risk ranged from 6.7% at age 20-29 to 48.2% at age 50-59. The mean number of teeth with active root lesions was 0.09 per person, and the mean number of teeth with root fillings was 1.25 at age 50-59.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

A comparison of daily fluoride intakes from food samples in Japan and Brazil.

The purpose of this study was to analyse the fluoride content of Japanese infant foods and foods in Brazil and to estimate daily fluoride intake calculated for a 6-month-old infant which reflects supplemental fluoride increased from infant foods and decreasing breast-feeding and commercial milk-feeding. Fluoride concentrations of 26 samples were assessed by a modified microdiffusion method and fluoride ion selective electrode. The fluoride content varied from 0.53 to 1.33 microgram/g for milk-base formulas, from 0.46 to 2.94 micrograms/g for infant foods in Japan, and from 0.06 to 0.25 microgram/g for foods in Brazil. The daily fluoride intake was calculated according to feeding pattern. The minimum and maximum fluoride values were 0.080 mg/day and 0.248 mg/day, respectively. These fluoride intakes, expressed in milligrams per kg of fluoride intake, ranged from 0.010 to 0.033 mg F/kg body weight. No significant differences in fluoride intake values were found between Japanese infant foods and foods in Brazil. The results of this study indicate that daily fluoride intakes of Japanese infant foods and foods in Brazil could be considered within the optimal recommended level.

Animals↗

PubMed1992

Caries experience in subjects 18-22 years of age after 13 years' discontinued water fluoridation in Okinawa.

The purpose of this study is to compare the state of teeth in young adults who had consumed fluoridated water from birth to 5-8 yr of age with the subjects who had non-fluoridated water. The sample consisted of 117 18-22-yr-old female nursing school students. The data obtained in dental examinations were sorted according to their place of residence, and then divided into groups depending on whether their place of residence had been supplied with fluoridated water or not. The fluoride concentration in the water had been 0.7-1.0 ppm in the six water supply systems which were under the control of the US military base. In the subjects who had fluoridated water, the following differences were found when compared to the control subjects: missing teeth and highly progressed caries occurred less frequently; significantly lower caries prevalence was present on free smooth and approximal surfaces; the overall DMFT differences in favor of the fluoridated subjects were small and non-significant.

Adolescent↗

PubMed1992

Decline in caries prevalence in 6-14-year-old schoolchildren during 1975-85 in Shizuoka, Japan.

The purpose of this study was to examine changes in caries prevalence during 1975-85 in Japanese schoolchildren who did not have an apparent change in fluoride exposure. A total of 2872 schoolchildren aged 6-14 yr in two primary schools and one junior high school in Shizuoka city, Japan, were examined in 1985. The caries prevalence in 1985 was then compared with data which had been collected in a longitudinal survey on schoolchildren in the same primary and junior high schools by Katayama in 1970-75. The results indicated that DMFT and DMFS indices in 1985 were significantly lower than those in 1970-75 in all the examined ages (P < 0.01). The DMFT indices at age 12 were 3.60 in 1985 and 5.47 in 1970-75. Remarkable decreases in DMFT at age 12 were observed in maxillary incisors (50%), followed by maxillary molars (24%) and mandibular molars (22%). The decline in caries prevalence in the examined area may be mainly attributed to several factors other than use of fluoride, such as changes in dietary pattern, an increasing dental awareness and promotion of dental health care. But the percentage decrease per annum of DMFT index at age of 12 in the examined population was relatively low (-4.1%) in comparison with other industrial countries. Comparing the results with data from national dental surveys, it can be considered that rural areas in Japan do not exhibit a similar decline of caries prevalence as in Shizuoka city, but there will be a lot of districts exhibiting significant reduction in caries prevalence in the near future.

Adolescent↗

PubMed1991

Inhibition of adsorption of oral streptococci to saliva treated hydroxyapatite by chitin derivatives.

This study estimated the effects of five chitin derivatives low molecular chitosan (LMCS), ethyleneglycol chitin (PEGT), carboxymethyl chitin (PCMT), sulphated chitosan (PSSS), and phosphorylated chitin (PPPT) on the adsorption of three oral streptococci to saliva-treated hydroxyapatite (S-HA). The adsorption was evaluated by measuring the optical density of the bacterial cell suspensions released from saliva-treated hydroxyapatite by 0.5 N HCl. The adsorption of test strains to S-HA progressively decreased in proportion to each additional volume of PEGT, PPPT, or PSSS. PPPT and PSSS quite effectively inhibited the adsorption of S. mutans onto S-HA, but were less effective against S. sanguis and S. mitis. PPPT, PSSS, and PCMT all markedly promoted the desorption of S. mutans cells pre-adsorbed onto S-HA. Pretreatment of S-HA with PPPT, PSSS, or PCMT significantly decreased the subsequent adsorption of S. mutans and S. mitis. Pretreatment of these cells with PEGT also decreased their adsorption to S-HA. These findings suggest that these chitin derivatives may change the ionic natures of the S-HA and the bacterial cell surface, resulting in a less favorable interaction.

Adult↗

PubMed1991

Validity of salivary thiocyanate as an indicator of cyanide exposure from smoking.

The purpose of this study was to evaluate the validity of salivary thiocyanate as an indicator of cyanide exposure from smoking. The salivary thiocyanate level showed wide variation, and the largest source of thiocyanate was hydrogen cyanide from cigarette smoke. Hydrogen cyanide in the mainstream of cigarette smoke was as high as 40-70 ppm, which is beyond the threshold limit value for occupational health (10 ppm). The hydrogen cyanide level in the sidestream smoke was lower less than 5 ppm. Thus the amount of cyanide intake was larger in active smokers than in passive ones. The correlation between the thiocyanate level in saliva and plasma was statistically significant. Thiocyanate levels in both plasma and saliva increased with the amount of cigarette smoke, and the discriminant powers (smoker versus non smoker) of thiocyanate levels in both plasma and saliva were quite similar. The smoker/non smoker ratio for salivary thiocyanate was 3.04 and that of plasma thiocyanate was 1.73. The result indicated that smoking status could be reflected more by the thiocyanate level in saliva than in plasma. The biological half life of salivary thiocyanate was estimated to be as long as 9.5 days from the changes salivary thiocyanate after stopping smoking. From the results of this study, it was concluded that salivary thiocyanate was a suitable indicator of habitual smoking exposure.

Humans↗

PubMed1990

Epidemiological analysis for the influences of plaque and calculus deposition on prevalence of pocket formation.

The influence of plaque and calculus deposition on the prevalence of pocket formation was studied using cross-sectional data from 615 Japanese manual workers aged 18-49. A periodontal pocket with a depth of 4 mm or more from gingival margin to bottom of the pocket was coded as presence of pockets. The oral hygiene status at the specified site was classified into four hygiene patterns as no deposition, deposition of plaque only, deposition of calculus only and deposition of both plaque and calculus. The percentages of six specified tooth types with pocket formation were analyzed according to the local hygiene condition. The results indicate that local oral hygiene produces significant differences in the proportion of teeth with pocket formation in the examined tooth types. The frequency of site-specific hygiene condition were no deposition, deposition of plaque only and deposition of both plaque and calculus, except for the lower central incisors. The teeth without plaque and calculus show no pocket formation in most of the examined tooth types in the subjects aged 18-39, while teeth with plaque and/or calculus indicate high prevalence of pocket formation. It is also revealed that the teeth with both plaque and calculus tend to show higher percentages of pocket formation than those with plaque only. These findings suggest that promotion of a plaque free state would reduce risk for pocket formation to negligible level, and that calculus deposition increase the risk for pocket formation around the teeth with plaque.

Adult↗

PubMed1990

SDS-polyacrylamide gel electrophoretic patterns of human parotid saliva treated with polyvinylpyrrolidone-iodine in vitro.

In the intraoral application of polyvinylpyrrolidone-iodine (PVP-I) as an antimicrobial agent, a color fading phenomenon is observed that might be caused by the binding of iodine with saliva. We have investigated the binding of iodine with saliva as iodine binding factor (IBF). The presence and characteristics of the IBF were investigated in parotid saliva stimulated by sour lemon drops, unstimulated parotid saliva, and whole saliva. A high level of the binding ability with iodine was observed in stimulated parotid saliva with the treatment of PVP-I compared with the unstimulated, but there were no significant differences in the amounts of total proteins between the stimulated and unstimulated. Electrophoretic patterns of saliva treated with PVP-I and untreated were examined to detect the IBF. The protein band of SDS-polyacrylamide gel electrophoresis near M.W. 60,000 of stimulated parotid saliva disappeared after treatment of PVP-I. This evidence indicates that the color fading phenomenon of PVP-I is associated with a polypeptide level in saliva.

Adult↗

PubMed1990

[Modified microdiffusion method for fluoride analysis of foodstuffs].

In fluoride analysis, there are two procedures for the determination of fluoride depending on nature of samples. One procedure directly can determine fluoride contents by fluoride ion electrode, dissociating fluoride from the sample with the acid (perchloric acid). The other procedure needs to separate fluoride from biological sample using steam-distillation or micro-diffusion method, and then the determination by means of fluoride ion electrode can be applied. In this study, we applied a modified microdiffusion method by Hinoide (1990) for its availability in different temperatures and reaction time, and then estimated to determine fluoride contents of Shrimp (Sakura-shrimp) as a biological sample by this method. It is also very important to determine fluoride contents of foodstuffs and biological samples with regard to bioavailability of fluoride in vivo. The results were as follows: 1. Using the modified microdiffusion method, the fluoride recovery rate attained more than 95% in the range of 0.1-10 micrograms fluoride from a standard solution under the experimental condition of 60 degrees C and 90 degrees C of reaction temperatures and 60, 90 and 120 minutes of reaction time. 2. For the sample of shrimp, fluoride contents analyzed by means of the modified micro-diffusion and steam-distillation methods showed almost similar values, although the fluoride contents by steam-distillation method revealed relatively lower value. The difference might be derived from a loss of fluoride in ashing the sample before applying the steam-distillation method. The modified microdiffusion method used in this experiment can be utilized routinely and precisely in fluoride analysis for small amounts of biological sample.

Animals↗

PubMed1989

[Dental health status of junior high school students in the suburbs of Chiba city].

The Population of 12-15 years is a key age group for oral health because the permanent dentition and periodontal tissues are almost complete at this stage. The purpose of this study was to evaluate oral health status and to develop an effective school dental health program for junior high schools students. The survey was performed on 527 persons aged 12-13 at 2 junior high schools in the suburbs of Chiba city. Periodontal disease was evaluated on the basis of the CPITN, and analyzed for severity and region of periodontal disease. Gingivitis was examined with PMA index, using color photo slides taken of anterior dentition at the time of inspection. At the same time, caries experience and oral hygiene index were also estimated. The results were as follows: (1) The mean DMFT was 3.89. Caries prevalence in females was higher than males. Ratio of treated teeth rate was 77.03%; that of untreated teeth rate was 22.65%. Females revealed less treatment for caries than males. Oral hygiene index showed significant difference between males and females. Labial and buccal parts of the maxillary and molar region on the mandibular showed remarkable plaque deposition. Calculus accumulation in this population was greatest on the lower incisor. (2) The mean PMA index was 7.36. Gingivitis was highly prevalent in both sexes, although it was more severe in males. There was correlations between PMA index and OHI. (3) From the results of CPITN, 10.6% of the subjects showed no signs of periodontal disease (Code 0), and 5.7% exhibited gingival bleeding (Code 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

[Distribution of dental plaque and time analysis of toothbrushing without instruction in school children and students].

The purpose of this study is to evaluate oral hygiene before and after individual method toothbrushing without instruction and to analyze toothbrushing times for school children from 6 to 13 years of age. Subjects were 150 pupils from primary to junior high school affiliated with the faculty of education of an university located in Setagaya, Tokyo: 38 first-grade pupils aged 6, 36 fourth-grade pupils aged 9, 37 sixth-grade pupils aged 11, and 39 second-year junior high school pupils aged 13. Assessments of dental plaque were made by two dentists using the PHP plaque score (Podshadely and Haley, 1968) for primary school pupils and OHI-S (only DI-S; Greene and Vermillion, 1964) for junior high school pupils. Plaque distribution disclosed by an Erythrosine solution was examined before and after toothbrushing, and the performance of toothbrushing by subjects was recorded on video-tape through a one-way mirror so that the children were unaware. Toothbrushing time was measured by 2 or 3 examiners using a time counter of video-monitor. Average scores for dental plaque before and after toothbrushing were almost the same for first and fourth-grade primary school pupils; but scores decreased with a statistically significant difference (p less than 0.01) for sixth-grade pupils. Distribution patterns of plaque scores for fourth-grade pupils showed characteristically narrow ranges (2-5 before brushing and 1-4 after brushing). The majority of subjects (69.4%) had scores of 2-3 after brushing, Whereas only 8.3% showed a range of 2-3 before brushing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

[Fluoride contents in tea and Sakura-shrimp in relation to other inorganic constituents].

The purpose of this study is to determine the fluoride contents of shrimp and of tea samples obtained from Shizuoka prefecture which is famous for tea products area and fishery market and to examine the relations between fluoride and other mineral contents, such as calcium, magunesium and phosphorus. Fluoride contents in tea produced in this area have been reported by Matsuura and Kokubu and other investigators, but more recent data are scarce. Samples were taken from a kind of shrimp known as Sakura-shrimp and from 4 kinds of commercial tea (coarse tea, 2 kinds of green tea and refined green tea). After having been dried and powdered, 1g of each sample was reduced to ashes at 550 degrees C for 10 hours with Ca(OH)2 as a fluoride fixative. Fluoride was distilled from each ash sample at about 140 degrees C with HClO4, and about 200 ml of distillate was collected from each sample. Fluoride contents were determined by means of ion-specific electrode. Calcium and magnesium contents were determined by atomic absorption spectrophotometry, and phosphorus contents were determined by Chen, Toribara and Warner's method. Total fluoride contents of the samples were as follows: 61.73ppm in shrimp, 180.16ppm in coarse tea, 72.62ppm and 89.02ppm in the 2 kinds of green tea, and 71.11ppm in refined green tea. More than 99% of the total fluoride was obtained from 150ml distillate of each sample. Calcium contents were extremely high in shrimp (21,822ppm) and 2,106-2,693ppm in tea samples. Magnesium contents were highest in shrimp (3,088ppm) and lowest in coarse tea (1,333ppm).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

The effects of ultrasonic scaling with oral hygiene education on the distribution of pathological pockets using CPITN diagnostic standards.

Thirty-three subjects aged 20-44 years, selected from Japanese company employees who had been given CPITN Codes of 3 or 4, received a treatment of ultrasonic scaling to investigate any changes in the distribution of pathological pockets after this treatment using CPITN diagnostic standards. A pathological pocket was defined as a pocket with a depth of 4 mm or deeper as described in the CPITN system. The results demonstrate that the number of teeth with pathological pockets was significantly reduced from 6.2 to 3.4 (45 per cent reduction) after scaling with an ultrasonic instrument requiring at most 30 minutes per subject. The reduction in pathological pockets was attributed to an improvement in shallow pockets rather than deep pockets. These results imply that as far as shallow pockets are concerned, one episode of scaling with ultrasonics is effective in reducing the extent of periodontal disease. Comparison between the number of sextants with shallow pockets before and after scaling further revealed that more improvements were observed in the subjects aged 20-29 years than in those aged 30-44 years. These results suggest that subjects aged 20-29 years with shallow pockets should be given first priority for scaling programmes in an adult population. The results also indicate that the CPITN diagnostic standards, in which the probe measures what is 'normal' and 'abnormal', is appropriate for the evaluation of periodontal status in an epidemiological study.

Adult↗

PubMed1988

Presence and absence of bleeding in association with calculus in segments given Code 2 in the Community Periodontal Index of Treatment Needs (CPITN).

The periodontal status of 257 Japanese company employees aged 20-56 yr was studied to determine the number and percentage of subjects with and without bleeding after gentle probing in the sextants given a Code 2 using the CPITN. In addition to recording the presence of calculus in the conventional manner, a modification was introduced to add a Code 2+ for sextants in which bleeding after probing was found and a Code 2- where no bleeding was detected. The results indicate that 38-52% of the sextants given a Code 2 showed no bleeding after probing. Such a large percentage of sextants with no evidence of bleeding in the presence of calculus raises a question about the priority which should be accorded to provide scaling for these subjects. The results also show that of the 116 subjects aged 20-29 yr judged to be in need of periodontal treatment by the CPITN criteria 18.1% showed neither pocket formation nor bleeding. Modifications to the CPITN are suggested which should make the index more appropriate for assessing both the prevalence of periodontal disease and the need for periodontal treatment and thus make it more useful for public health planning and evaluation purposes.

Adult↗