No abstract available.
Oocytes* ; Pregnancy* ; Spermatozoa*

We evaluated the association between sleep duration, dental caries, and periodontitis by using representative nationwide data. We examined 8,356 subjects aged ≥19 years who participated in the sixth Korea National Health and Nutrition Examination Survey (2013~2014). Sleep duration were grouped into ≤5, 6, 7, 8, and ≥9 hours. Presence of dental caries was defined as caries in ≥1 permanent tooth on dental examination. Periodontal status was assessed by using the community periodontal index (CPI), and a CPI code of ≥3 was defined as periodontitis. A chi-square test and multiple logistic regression analysis were used to determine statistical significance. Model 1 was adjusted for age and sex, model 2 for household income, educational level, and marital status plus model 1, and model 3 for smoking status, alcohol consumption, blood pressure level, fasting blood glucose level, total cholesterol level, and body mass index plus model 2. The prevalence of dental caries according to sleep duration showed a U-shaped curve of 33.4%, 29.4%, 28.4%, 29.4%, and 31.8% with ≤5, 6, 7, 8, and ≥9 hours of sleep, respectively. In the fully adjusted model 3, the risk of developing dental caries was significantly higher with ≤5 than with 7 hours of sleep (odds ratio, 1.23; 95% confidence interval, 1.06~1.43). The prevalence of periodontitis according to sleep duration showed a U-shaped curve of 34.4%, 28.6%, 28.1%, 31.3%, and 32.5%, respectively. The risk of periodontitis was significantly higher with ≥9 than with 7 hours of sleep in models 1 and 2, whereas the significant association disappeared in model 3. In a nationally representative sample, sleep duration was significantly associated with dental caries formation and weakly associated with periodontitis. Adequate sleep is required to prevent oral diseases such as dental caries and periodontitis.
Adult* ; Alcohol Drinking ; Blood Glucose ; Blood Pressure ; Body Mass Index ; Cholesterol ; Dental Caries* ; Family Characteristics ; Fasting ; Health Surveys ; Humans ; Korea* ; Logistic Models ; Marital Status ; Nutrition Surveys* ; Periodontal Index ; Periodontitis* ; Prevalence ; Smoke ; Smoking ; Tooth

Vascular changes in the periodontal ligament of the rat incisors following application of experimental orthodontic forces were examined by the India ink perfusion method. 57 rats were used for this experiment. The rats were divided into experimental group (54 rats) and control group (3 rats). 54 experimental rats were divided into group I (27 rats) and group II (27 rats). The right and left upper incisors of group. I and group II rats were separated distally with forces of 20gm, 70gm respectively. The vascular changes of periodontal ligament were observed histologically by means of light microscope after 1,2 and 3 days of tooth movement and 1,3,5,8,14, and 21days after removal of orthodontic force. The results were as follows; 1. After one day of tooth movement, occlusion of blood vessels, hyalinization of periodontal ligament and resorption of alveolar bone adjacent to the alveolar crest on pressure side were observed. Above the tissue changes on the pressure side of group II were more severe than those of group I. Especially, septal bone of group II was separated after 2 days of tooth movement. 2. In tension zones, periodontal space was widened and periodontal fibers were orientated in the direction of pull. The blood vessels of periodontal ligament were distended. New bone deposition was seen along the inner surface of the alveolus after 2 days of tooth movement. 3. After 3 days of tooth movement, deposition of new bone was seen along the periosteal surface of alveolar bone on pressure side, progressing with increasing after removal of orthodontic force. Remodelling of the new bone was occurred 5 days after removal of orthodontic force. 4. 3 days after removal of orthodontic force, invasion of blood vessels into the marginal periodontal ligament on pressure side was observed clearly and the vessels below the epithelial attachment were increased. 5. After removal of orthodontic force, hyalinized structures disappeared concomittantly with an invasion of blood vessels from the neighboring periodontal ligament. 14 days after removal of orthodontic force, the vessels in the periodontal ligament of group I were finished the vascular rearrangement. 21 days after removal of orthodontic force, the vessels in the periodontal ligament of group II were finished the vascular rearrangement.
Animals ; Blood Vessels ; Epithelial Attachment ; Hyalin ; Incisor* ; India ; Ink ; Perfusion ; Periodontal Ligament ; Rats* ; Tooth Movement* ; Tooth*

PURPOSE: The purpose of this study was to investigate whether the re-osseointegration of the implants that had mechanical unscrewing possibly occurred or not. Furthermore, if it happened, the degree of re-osseointegration was evaluated by comparing with previous osseointegration. MATERIALS AND METHODS: The smooth implant (commercial pure titanium 99%) specimens, whose diameter and length was 3.75 mm, 4 mm, respectively were produced. Two implants were inserted into each tibia of 7 New Zealand female white rabbits weighing at least 3.0 kg. The torque removal force for each implant after 6 weeks of implants placement was measured and included in group I . The torque removal forces were assessed after the fixtures were re-screwed to original position and the subjects were allowed to have 4 more weeks for healing and included in group II. One rabbit was sacrificed after first measurement and produced 4 slide specimens in group I, and two rabbits were sacrificed after 2nd measurement, 7 slide specimens, in group II for histomorphologic investigations. All slide specimens were assessed based on the proportion of BIC (bone-implant contact) as well as CBa (Bone area in the cortical passage) value produced by counting the screw threads embedded in the compact bones under the optical microscopic analysis (x20). Statistical analysis was conducted to evaluate the torque removal force, BIC and CBa between group I and II. RESULTS: As for the torque removal force, the result was 10.8 +/- 3.6 Ncm for group I and 20.2 +/- 9.7 Ncm for group II. Furthermore, the torque removal force of group II increased by 98.1% in average compared to group I (P < .05). On the other hand, histomorphologic analysis displayed that there was no statistical significance in BIC and CBa values between group I and the group II (P > .05), and RT/BIC and RT/CBa between group I and group II were statistically significant (P < .05). CONCLUSION: It is possible to obtain more substantial re-osseointegration within shorter periods than the period needed for the initial osseointegration in case of iatrogenically unscrewed implants.
Female ; Hand ; Humans ; New Zealand ; Nitrogen Mustard Compounds ; Osseointegration ; Rabbits ; Tibia ; Titanium ; Torque

OBJECTIVE: The purpose of this study was to evaluate the prognostic value of sleep apnea syndrome in stroke patients by polysomnography. METHOD: Fifteen patients with ischemic stroke were studied with polysomnography. Medical history, sleep history, location of stroke, and severity of neurological deficit were recorded. Patients were observed by physician for evidence of snoring and excessive daytime sleepiness. Functional abilities were measured with the use of the Modified Barthel Index (MBI). To evaluate the autonomic nervous system, heart rate variability (HRV) study was done. RESULTS: Mean SaO2 during polysomnography was 88.2%, and mean recording time was 321 minutes. Apnea types were obstructive, mixed, and central. Respiratory Distress Index (RDI) correlated with functional outcome and mean SaO2. HRV study showed no significant changes under the orthostatic stress in apnea patients. CONCLUSION: We concluded that the sleep apnea syndrome could be a prognostic factor in rehabilitation outcome of stroke.
Apnea ; Autonomic Nervous System ; Heart Rate ; Humans ; Polysomnography ; Prognosis* ; Sleep Apnea Syndromes* ; Snoring ; Stroke* ; Treatment Outcome

Operators of hospital sterilizers who use ethylene oxide (EtO) were studied to determine the exposure of EtO level and the frequency of sister chromatid exchanges (SCEs) from June 12 to July 20, 1997. To evaluate SCEs in the peripheral blood cells, we selected 22 workers at the central supply room of 4 university hospitals and 22 unexposed workers at the same hospitals according to match sex, age, and smoking habit and also did questionnaires. The mean air concentrations (8-hr TWA) of EtO at 4 university hospitals were less than 1 ppm. The SCE frequencies in exposed workers to EtO and controls were normally distributed. The SCE frequencies in exposed workers to EtO and controls were 6.42+/-.63, 5.86+/-.69, respectively and their differences were statistically significant (p=0.0093). But there were no statistically significant differences in smoking, alcohol intake, coffee drinking. Especially smokers who exposed to EtO were increased SCE statistically significant than the exposed group who did not smoke.
Blood Cells ; Coffee ; Drinking ; Ethylene Oxide* ; Hospitals, University ; Humans ; Occupations* ; Questionnaires ; Siblings* ; Sister Chromatid Exchange* ; Smoke ; Smoking

OBJECTIVE: To achieve optimal fit of implant, it is necessary to bend the implant during spine surgery. Bending procedure may decrease stiffness of plate especially made of titanium and stainless steel. Typically titanium suffers adverse effects including early crack propagation when it is bent. We investigate whether 6 degree bending of titanium plates would decrease the stiffness after full cyclic loading by comparing with non-bending titanium plates group. METHODS: Authors experimented 40 titanium alloy plates of 57mm in length, manufactured by 5 different companies. Total 40 plates were divided into two groups (20 bent plates for experimental group and 20 non-bent plates for control group). Twenty plates of experimental group were bent to 6 degree with 3-point bending technique and verified with image analyzer. Using the electron microscope, we sought for a initial crack before and after 3-point bending. Mechanical testing by means of 6000 cyclic axial-compression loading of 35N in compression with moment arm of 35mm-1.1Nm was conducted on each plate and followed by the electron microscopic examination to detect crack or fissure on plates. RESULTS: The stiffness was decreased after 6000 cyclic loading, but there was no statistically significant difference in stiffness between experimental and control group. There was no evidence of change in grain structure on the electron microscopic magnification. CONCLUSION: The titanium cervical plates can be bent to 6 degree without any crack or weakness of plate. We also assume that minimal bending may increase the resistance to fatigue fracture in cervical flexion-extension movement.
Alloys ; Arm ; Edible Grain ; Fatigue* ; Fractures, Stress ; Spine* ; Stainless Steel ; Titanium

We investigated a topographical distribution of managanese, and immunohistochemical density of tyrosine hydroxylase (TH), and histopathologic findings in globus pallidus and substantia nigra according to manganese dose and time course in the brain of rats which received MnCl2 intravenously. Topographical distribution of manganese was also investigated after injection of FeCl2. The manganese concentrations of brain in control and experimental group were highest in pituitary gland and thalamus, and lowest in the cerebral cortex. The manganese concentration of blood was increased proportionally to the dose administered, and the biological half-life of blood manganese was between 21 and 42 days. The manganese concentrations of brain were increased proportionally to the dose, and increase rate was highest in olfactory bulb, and the biological half-lives of brain manganese ranged from 42 days to 90 or more days; the longest were observed in pituitary gland, medulla oblongata and cerebral cortex. In case of administration of FeCl2, the manganese concentrations of brain were higher than that of control group in dose of 2.5 mg/kg, and decreased proportionally to the administered dose, resulting in lower level compared with control group in high dose of FeCl2 administered. Significantly decreased number of nerve cell and increased gliosis in globus pallidus were observed in experimental group, which were closely correlated with the duration after manganese injection, but no significant change of number of nerve cell expressing TH and gliosis were observed in substantia nigra. Density of immunohistochemical reaction for TH in globus pallidus made little difference between control and experimental group. These results suggest that pathology of manganese intoxication is caused by the loss of nerve cells in globus pallidus, and closely correlated with the duration after manganese exposure.
Animals ; Brain* ; Cerebral Cortex ; Gliosis ; Globus Pallidus ; Half-Life ; Manganese* ; Medulla Oblongata ; Neurons ; Olfactory Bulb ; Pathology ; Pituitary Gland ; Rats* ; Substantia Nigra ; Thalamus ; Tyrosine 3-Monooxygenase

OBJECTIVES: We aimed to investigate the relationship between subjective memory complaints and cognition in the elderly. METHODS: Data obtained from 1,496 subjects (510 men and 986 women) aged above 60 years was analyzed from the Gwangju Dementia and Mild Cognitive Impairment Study (GDEMCIS). All subjects completed the study questionnaire including demographic characteristics, history of current and past illnesses, drug history, Korean version-Mini Mental State Examination (K-MMSE), and Short Form Korean version of Geriatric depression scale (SGDS-K). Subjective memory complaints were defined in two different ways; worse than others (SMC-O) and worse than one's past (SMC-P). RESULTS: On analysis of covariance, there was significant difference of estimated marginal means of K-MMSE score among five SMC-P groups (much improve:18.0, little improve:21.3, not changed:21.2, little worse:21.1, much worse:20.2) after adjusting age, sex, educational level and depression (F=9.63, df=4, p<0.0001, adjusted R2=0.375). There was significant difference of estimated marginal means of K-MMSE score among three SMC-O groups (below peer's average:20.4, peer's average:20.9, above peer's average:21.8) after adjusting age, sex, educational level and depression (F=4.89, df=2, p=0.043, adjusted R2=0.0.361). CONCLUSION: These results suggest that subjective memory complaints may be an indicator of objective cognitive impairment in the elderly.
Aged ; Cognition ; Dementia ; Depression ; Humans ; Male ; Memory ; Mild Cognitive Impairment ; Surveys and Questionnaires

This study was started to find out if plasma malondialdehyde(MDA), alpha-tocopherol and erythrocyte superoxide dismutase(SOD) activity could be markers of biological activity resulting from exposed to lead in workers. Blood samples were randomly obtained from lead -exposed workers(n=29), CO2 welders(n=60) and office workers(n=60). We used whole blood to analyse blood lead with atomic absorption spectrophotometer. Superoxide dismutase activity in erythrocyte was measured with spetrophotometer. MDA and alpha-tocopherol in plasma were measured with high performance liquid chromatography. Lead-exposed workers was significantly high in blood lead concentration(29.37 ng/dl) compared with welders(6.42 ng/dl) and office workers(5.01 ng/dl). The level of plasma MDA was significantly higher in the lead-exposed workers(1.87 nmol/g cholesterol) than the welders(1.41 nmol/g cholesterol) and office workers(1.41 nmol/g cholesterol). Erythrocyte SOD activity in lead-exposed workers(56.80 U/g Hb) was significantly increased than those of welders(37.63 U/g Hb) and office workers(20.47 U/g Hb). The plasma alpha-tocopherol level of lead-exposed workers(4.93 ng/g cholesterol) was statistically different from welders(4.25 ng/g cholesterol) and office workers(4.28 ng/g cholesterol). Neither age nor smoking was related to SOD or MDA level. Blood lead was significantly correlated with erythrocyte SOD activity(r=0.405), plasma MDA(r=0.296) and alpha-tocopherol(r=0.207). Plasma MDA was also significantly correlated with SOD (r=0.217). In multiple regression analysis, the change of MDA and SOD activity level related to the blood lead concentration. These results suggested that the increase of plasma MDA and erythrocyte SOD activity in lead-exposed workers had a close relationship with the oxidative stress induced by lead.
Absorption ; alpha-Tocopherol ; Antioxidants* ; Chromatography, Liquid ; Erythrocytes ; Lipid Peroxidation* ; Oxidative Stress ; Plasma ; Smoke ; Smoking ; Superoxide Dismutase ; Superoxides