STATEMENT OF PROBLEM: Recently Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) has been introduced due to superior flexural strength and fracture toughness compared to other dental ceramic systems. Although zirconia has outstanding mechanical properties, the phenomenon of decrease in the life-time of zirconia resulted from degradation in flexural strength after low temperature aging has been reported. PURPOSE: The objective of this study was to investigate degradation of flexural strength of Y-TZP ceramics after various low temperature aging treatments and to evaluate the phase stability and micro-structural change after aging by using X-ray diffraction analysis and a scanning electron microscope (SEM). MATERIAL AND METHODS: Y-TZP blocks of Vita In-Ceram YZ (Vita Zahnfabrik, Bad Sackingen, Germany) were prepared in 40 mm (length) x 4 mm (width) x 3 mm (height) samples. Specimens were artificially aged in distilled water by heat-treatment at a temperature of 75, 100, 125, 150, 175, 200, and 225degrees C for 10 hours, in order to induce the phase transformation at the surface. To measure the mechanical property, the specimens were subjected to a four-point bending test using a universal testing machine (Instron model 3365; Instron, Canton, Mass, USA). In addition, X-ray diffraction analysis (DMAX 2500; Rigaku, Tokyo, Japan) and SEM (Hitachi s4700; Jeol Ltd, Tokyo, Japan) were performed to estimate the phase transformation. The statistical analysis was done using SAS 9.1.3 (SAS institute, USA). The flexural strength data of the experimental groups were analyzed by one-way analysis of variance and to detect statistically significant differences (alpha= .05). RESULTS: The mean flexural strength of sintered Vita In-Ceram YZ without autoclaving was 798 MPa. When applied aging temperature at below 125degrees C for 10 hours, the flexural strength of Vita In-Ceram YZ increased up to 1,161 MPa. However, at above 150degrees C, the flexural strength started to decrease. Although low temperature aging caused the tetragonal-to-monoclinic phase transformation related to temperature, the minimum flexural strength was above 700 MPa. CONCLUSION: The monoclinic phase started to appear after aging treatment above 100degrees C. With the higher aging temperature, the fraction of monoclinic phase increased. The ratio of monoclinic/tetragonal + monoclinic phase reached a plateau value, circa 75% above 175degrees C. The point of monoclinic concentration at which the flexural strength begins to decrease was between 12% and 54%.
Aged ; Aging ; Aluminum Oxide ; Ceramics ; Collodion ; Dental Porcelain ; Electrons ; Humans ; Phenothiazines ; Tokyo ; Water ; X-Ray Diffraction ; Yttrium ; Zirconium

Neurologic studies were done on 7 neuro-Behcet's syndrome patients, admitted from June 1985 to June 1986. They were from 30 to 43 years of age with mean age nf 35. 3;3 were male and 4 female. Symptoms fitting more than 3 of the 4 major diagnostic criteria included in Shimizu's classification preceded the neurological symptoms in all 7 patients and they progressed to neuro-Behcet syndrome approximately 5 years after the appearance of the first major syrnptoms of Behcet's syndrome, Severe headache was seen in all 7 patients. Ataxia, dysarthria, increased DTR, and herniplegia. were other rnajor signs found and psychiatric symptoms were present in 2 cases. The cases were neurologically classified as brain stem syndrome in 3 male patients, meningo-encephalitic syndrome in 1, and mixed type in 3. Characterletic laboratory findinge were lncreaeed mononuclear celle in CSF, peripheial blood leukocytosis, and decreased lymphocyte blastogenesis.
Ataxia ; Behcet Syndrome* ; Brain Stem ; Classification ; Dysarthria ; Female ; Headache ; Humans ; Leukocytosis ; Lymphocyte Activation ; Lymphocytes ; Male

It had been reported by many authors that the incidence of delayed or nonunion in fracture of clavicle was higher in open reduction and internal fixation than conservative treatment. The purpose of this study is to verify the gratification of the reconstruction plate in fracture of clavicle which needed internal fixation. From March 1993 to September 1995, 32 clavicular fractures were underwent open reduction and internal fixation with reconstruction plate for the wide gap, soft tissue interposition and comminuted fracture etc. The results were as follows 1. The range of motion of the shoulder was returned to normal range within 1.5 weeks except one case who had brachial plexus injury. 2. All cases had bony union. Average time to clinical union was 2.9 weeks and the bony union 7.8 weeks. 3. By functional evaluation of shoulder by Weitzman, final results were excellent in 27, good in 4 and fair in l. 4.Fixation and maintenance of clavicular fragment by reconstruction plate was recommendable for wide separated, soft tissue interposed, comminuted fracture of the clavicle. We concluded that reconstruction plate in fracture of clavicle could be recommended as one of the device for internal fixation.
Brachial Plexus ; Clavicle ; Fractures, Comminuted ; Incidence ; Range of Motion, Articular ; Reference Values ; Shoulder

The significance of the posterior cruciate ligament (PCL) in the stability of the knee and the necessity for surgical repair of its tears are still controversial. The purpose of this study is to present the short term results of surgical repair and Kennedy LAD augmentation for 15 cases with PCL injury. In 14 patients (15 knees), the torn PCL was repaired with pullout suture technique and Kennedy LAD augmentation was done from june 1993 to june 1994. The follow-up period ranged from 12 months to 25 months (average, 18months). The main causes of injuries were traffic accidents in 12. Thirteen of the patients were men and one was a woman, ranging in age from 17 to 52 years(average, 35 years). 10 knees were acute injury and repaired at average 9 days after injury. There were 11 cases that had combined injuries(4 ACL injuries, 4 meniscus injuries, 3 MCL injuries etc). In eight knees, the tear was in mid substance area and in five it was near femoral attach site and in two it was near tibial attach site. Postoperative results were evaluated by roentgenographic evaluation of posterior sagging and Lysholm knee score. 11 knee were stable but 4 knees were unstable posteriorly during postoperative follow-up period. 3 chronic injuried knees were included in 4 posteriorly unstable knees. There are 7 combined knee injuries in 11 stable knees and no combined injuries in unstable knees and average Lysholm knee score was 89.7 in stable knees and 90 in unstable knees and there was no significant difference between two groups. On the based of this study, surgical repair with pollout suture technique and augmentation with Kennedy LAD in acute PCL injury is a one of the good method for preventing posterior sagging but more longer follow-up period and more cases must be needed to accept this method.
Accidents, Traffic ; Female ; Follow-Up Studies ; Humans ; Knee ; Knee Injuries ; Lysholm Knee Score ; Male ; Methods ; Posterior Cruciate Ligament ; Suture Techniques ; Tears

Acute mountain sickness is an illness caused by climbing to a high altitude without prior acclimatization. Neurological consequences, like parkinsonism following acute mountain sickness without lesion of brain MRI have been reported rarely. A healthy 56-year-old man presented with dysarthria and gait disturbance. Neurological examination revealed tremor of hands, limb rigidity, and bradykinesia. The symptoms developed approximately 30 days following a 3,500 m climb of the Annapurna in the Himalayas. Brain MRI did not reveal any abnormalities including globus pallidus. The parkinsonism symptoms persisted for about 3 months before a complete recovered was made. We suggest that parkinsonism can develop after climbing to a high altitude but that the symptoms can be transient if a brain MRI detects no abnormalities.

No abstract available.
Kidney Transplantation*

No Abstract Available.
Pterygium*

Identifying precancerous conditions such as atrophic gastritis and intestinal metaplasia (IM) has a crucial role in detecting high risk patients for gastric cancer. White light imaging (WLI) is a basic tool for diagnosing these premalignant conditions, however its low accuracy and high variability has been a serious problem in diagnosing these premalignant conditions. Several noble imaging technologies, such as magnifying endoscopy, narrow band imaging, autofluorescence imaging, and confocal laser endomicroscopy, provids us with chances of overcoming the limitations of conventional WLI. Autofluorescence images help us understand the extent of atrophic gastritis with vivid colors. Magnifying endoscopy with narrow band imaging shows microsurface structure and micrvascular architecture and is able to identify the degree of intestinal metaplasia by the presence of "light blue crest" sign. Confocal laser endomicroscopy produces reliable images of goblet cells that can replace biopsy. Usefulness of the new endoscopic imaging techniques for predicting gastric cancer development needs to be validated in clinical practice. Currently, it would be practical to apply magnifying endoscopy with narrow band imaging sequentially after white light endoscopy for identifying the presence of IM and atrophic gastritis.
Biopsy ; Endoscopy ; Gastritis, Atrophic ; Goblet Cells ; Humans ; Light ; Metaplasia ; Narrow Band Imaging ; Optical Imaging ; Precancerous Conditions ; Stomach Neoplasms

The topic of the extragastric manifestations of Helicobacter pylori infection continues to capture the attention of many researchers all over the world. There are, in fact, several studies concerning obesity, diabetes mellitus, cardiovascular diseases, lung diseases, hematologic diseases, eye and skin diseases, hepatobiliary diseases, and neurological disorders. Among them, obesity and related disorders are hot spots in modern society. Here, we review the results of the studies about the relationship between Helicobacter pylori infection and obesity related diseases.
Cardiovascular Diseases ; Diabetes Mellitus ; Eye ; Helicobacter ; Helicobacter pylori ; Hematologic Diseases ; Lung Diseases ; Metabolic Diseases ; Nervous System Diseases ; Obesity ; Skin Diseases

Priapism is a relatively rare condition of persistent painful erection unaccompanied by sexual desire. We report two cases of priapism, one etiology is related to leukemia and the other is idiopathic. The former was treated with continuous Hemo-Vac drainage, the latter with corporal cavernosum spongiosum shunt, and the results were good.
Drainage ; Leukemia ; Priapism*