The purpose of this study was to compare the changes of retentive force in different stud attachment systems for implant retained overdenture. Two commercially available attachments with different retentive forces were investigated: Kerator (pink, blue, red) and O-ring (orange, red). Two implant fixtures were vertically embedded in base mountings. Five pairs of each attachment were evaluated. A universal testing machine was used to evaluate the retentive force of two attachments during wear simulation. Surface characteristics of each attachment system were evaluated with scanning electron microscopy. Five pairs of each attachment were evaluated. Kerator pink showed the highest initial retention. After 2,500 cycles of wear-simulation, Kerator pink noted the largest decrease in retention. According to results of surface analysis, Worn surfaces were obtained in matrices and patrices. Heavy wears were observed in matrices. After 2 year-wear simulation, most attachments exhibited retention loss. Attachments using different kind of material exhibited dissimilar surface alterations.
Denture, Overlay* ; Microscopy, Electron, Scanning

No abstract available.
Intracranial Arteriovenous Malformations* ; Radiosurgery*

Human cardiomyocytes (CMs) cease to proliferate and remain terminally differentiated thereafter, when humans reach the mid-20s. Thus, any damages sustained by myocardium tissue are irreversible, and they require medical interventions to regain functionality. To date, new surgical procedures and drugs have been developed, albeit with limited success, to treat various heart diseases including myocardial infarction. Hence, there is a pressing need to develop more effective treatment methods to address the increasing mortality rate of the heart diseases. Functional CMs are not only an important in vitro cellular tool to model various types of heart diseases for drug development, but they are also a promising therapeutic agent for cell therapy. However, the limited proliferative capacity entails difficulties in acquiring functional CMs in the scale that is required for pathological studies and cell therapy development. Stem cells, human pluripotent stem cells (hPSCs) in particular, have been considered as an unlimited cellular source for providing functional CMs for various applications. Notable progress has already been made: the first clinical trials of hPSCs derived CMs (hPSC-CMs) for treating myocardial infarction was approved in 2015, and their potential use in disease modeling and drug discovery is being fully explored. This concise review gives an account of current development of differentiation, purification and maturation techniques for hPSC-CMs, and their application in cell therapy development and pharmaceutical industries will be discussed with the latest experimental evidence.
Cell- and Tissue-Based Therapy ; Drug Discovery ; Drug Industry ; Heart Diseases ; Humans* ; In Vitro Techniques ; Mortality ; Myocardial Infarction ; Myocardium ; Myocytes, Cardiac* ; Pluripotent Stem Cells* ; Stem Cells

We present 10 patients who underwent temporal lobe surgery for seizure control on our institution between December, 1992 and October, 1994. Preoperative neuroimaging studies of all 10 patients showed calcified mass lesions within the temporal lobe. Among them, 5 cases had mesial temporal calcified mass close to the hippocampus, 3 diffuse mass in the temporal lobe or multilobes and 2 in the temporal tip. All patients presented with complex partial seizure and seven had secondary generalization from their seizures. The duration of epileptic seizure varied between 4 and 23 years(mean 13 year). The patients were refractory to therapeutic levels of anticonvulsant medication. Presurgical evaluations of epilepsy included a detailed clinical history, multiple scalp/shenoidal EEG, prolonged Video-EEG monitoring, neuroimaging, neuropsychological test, WADA test and invasive study with subdural strip electrodes. Anterior temporal lobectomy with lesionectomy were performed in six cases and anterior temporal lobectomy in four cases using intraoperative electrocorticography(EcoG) and/or functional mapping under local or general anesthesia. The extent of resection of amygdala and hippocampus were determined according to electrocorticographic findings. The verified histopathology of the calcified lesions revealed 1 oligodendroglioma, 1 mixed glioma, 1 arterioveous malformation, 1 paragonimiasis, 2 neurocysticercosis, 1 other parasitic granuloma and 3 calcified fibrous nodule. In four patients, severe hippocampal sclerosis with neuronal cell loss and gliosis were observed. After a mean postoperative follow-up of 9 months, 9 patients showed a seizure-free outcome and one patient a significant reduction in seizure activity. We conclude from our studies that temporal lobe surgery for patients refractory to therapeutic levels of long-term anticonvulsant medication can result in excellent postoperative seizure-free outcome in the majority of the patients, and that brain tumors, vascular malformations, and parasitic infections may be considered as etiologic factors of calcified mass lesions in the temporal lobe of such patients.
Amygdala ; Anesthesia, General ; Anterior Temporal Lobectomy ; Brain Neoplasms ; Electrodes ; Electroencephalography ; Epilepsy* ; Follow-Up Studies ; Generalization (Psychology) ; Glioma ; Gliosis ; Granuloma ; Hippocampus ; Humans ; Neurocysticercosis ; Neuroimaging ; Neurons ; Neuropsychological Tests ; Oligodendroglioma ; Paragonimiasis ; Sclerosis ; Seizures ; Temporal Lobe* ; Vascular Malformations

No abstract available.
Animals ; Neurons* ; Rats*

The pterional(Transsylvian) and subtemporal approaches are main surgical route for direct clipping of basilar bifurcation and basilar-superior cerebellar artery aneurysms. In general , the pterional approach has the advantage for high placed aneurysm and the subtemporal approach has the advantage for low placed and posterior directed aneurysm of basilar bifurcation. The authors has been performed surgery for 5 cases of basilar bifurcation and basilar-superior cerebellar artery aneurysms through subtemporal route during 1.5 years with good results in 3 cases, fair result in 1 case, and death in 1 case. We described about this 5 cases detaily and discussed the subtemporal approach for these lesions.
Aneurysm* ; Arteries*

PURPOSE: Thyroid cancer is the most common malignancy in Korean females and can be treated with good prognosis. However, drugs to treat aggressive types of thyroid cancer such as poorly differentiated or anaplastic thyroid cancer have not yet been established. To that end, we analyzed the effects of berberine on human thyroid cancer cell lines to determine whether this compound is useful in the treatment of aggressive thyroid cancer. MATERIALS AND METHODS: The two thyroid cancer cell lines 8505C and TPC1, under adherent culture conditions, were treated with berberine and analyzed for changes in cell growth, cell cycle duration, and degree of apoptosis. RESULTS: Following berberine treatment, both cell lines showed a dose-dependent reduction in growth rate. 8505C cells showed significantly increased levels of apoptosis following berberine treatment, whereas TPC1 cells showed cell cycle arrest at the G0/G1 phase. Immunobloting of p-27 expression following berberine treatment showed that berberine induced a little up-regulation of p-27 in 8505c cells but relatively high up-regulation of p-27 in TPC1 cells. CONCLUSION: These results suggest that berberine treatment of thyroid cancer can inhibit proliferation through apoptosis and/or cell cycle arrest. Thus, berberine may be a novel anticancer drug for the treatment of poorly differentiated or anaplastic thyroid cancer.
Antineoplastic Agents/*pharmacology ; Apoptosis/drug effects ; Berberine/*pharmacology ; Cell Cycle/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Humans ; Thyroid Neoplasms/*metabolism

In order to find out the effect of induced hypotension and temporary clipping during aneurysmal surgery on postoperative patients, we analysed 143 cases who had received surgery from September, 1982 to April, 1988. We divided these surgical cases into two groups, those without temporary clipping and those with temporary clipping during surgery, excluding cases of definite surgical complications. Of the patients in the non-temporary clipping group, we evaluated the relationship between the degree of the mean blood pressure(MBP) during surgery with the postoperative conduction of the patients according to the preoperative clinical grade. Of those in the temporary clipping group, we also evaluated the relationship between the degree of the MBP, site and duration of the temporary clipping during surgery with the postoperative condition of the patients according to preoperaitve clinical grades. The rate of temporary deterioration, delayed sequela and death, possibly from induced hypotension or the temporary clipping procedure, was higher in those whom the MBP was lowered to 60 mmHg during surgery than in those whom the MBP was maintained at 80 mmHg and 70 mmHg(temporary deterioration : 27.3% vs. 23.1% vs. 13.3%, delayed sequela : 4.5% vs. 0.0% vs. 0.0%, and death : 9.1% vs. 0.0% vs. 3.3%, respectively in non-temporary clipping group and temporary deterioration : 33.3% vs. 22.2% vs. 21.1%, and death : 22.2% vs. 0.0% vs. 10.5%, respectively in temporary clipping group). In the non-temporary clipping group, preoperative clinical grades 1,2 and 3 patients did not deteriorate until after 20 minutes of hypotension(MBP : < or = 60 mmHg). However, patients of preoperative clinical grade 4 and 5 showed temporary deterioration after 10 minutes of hypotension(MBP : < or = 60 mmHg). There was no deterioration in patients whom the duration of the temporary clipping was within 15 minutes at an intracranial internal carotid artery and a middle cerebral artery at various MBP's, but, in the cases who had a temporary clipping at the anterior cerebral artery, the safety duration of the temporary clipping was 15 minutes at 80 mmHg, 7 minutes at 70 mmHg and 3 minutes at 60 mmHg of the MBP. Induced hypotension during aneurysmal surgery had some risk and it increased in hypertensive, poor clinical grade patients, and when the MBP was lowered to 60 mmHg. The safety duration of a temporary clipping might be increased with the raising of the MBP or administration of a brain protective agent at the time of the temporary clipping during surgery.
Aneurysm ; Anterior Cerebral Artery ; Brain ; Carotid Artery, Internal ; Humans ; Hypotension* ; Intracranial Aneurysm* ; Middle Cerebral Artery

Objective: To investigate molecular and functional consequences of additional exposures to iodine- or gadolinium-based contrast agents within 24 hours from the initial intravenous administration of iodine-based contrast agents through an animal study. Materials and Methods: Fifty-six Sprague–Dawley male rats were equally divided into eight groups: negative control, positive control (PC) with single-dose administration of CT contrast agent, and additional administration of either CT or MR contrast agents 2, 4, or 24 hours from initial CT contrast agent injection. A 12 µL/g of iodinated contrast agent or a 0.47 µL/g of gadoliniumbased contrast agent were injected into the tail vein. Serum levels of blood urea nitrogen, creatinine, cystatin C (Cys C), and malondialdehyde (MDA) were measured. mRNA and protein levels of kidney injury molecule-1 (KIM-1) and neutrophil gelatinaseassociated lipocalin (NGAL) were evaluated. Results: Levels of serum creatinine (SCr) were significantly higher in repeated CT contrast agent injection groups than in PC (0.21 ± 0.02 mg/dL for PC; 0.40 ± 0.02, 0.34 ± 0.03, and 0.41 ± 0.10 mg/dL for 2-, 4-, and 24-hour interval groups, respectively; P < 0.001). There was no significant difference in the average Cys C and MDA levels between PC and repeated CT contrast agent injection groups (Cys C, P = 0.256–0.362; MDA, P > 0.99). Additional doses of MR contrast agent did not make significant changes compared to PC in SCr (P > 0.99), Cys C (P = 0.262), and MDA (P = 0.139–0.771) levels. mRNA and protein levels of KIM-1 and NGAL were not significantly different among additional CT or MR contrast agent groups (P > 0.05). Conclusion A sufficient time interval, probably more than 24 hours, between repeated contrast-enhanced CT examinations may be necessary to avoid deterioration in renal function. However, conducting contrast-enhanced MRI on the same day as contrast-enhanced CT may not induce clinically significant kidney injury.

PURPOSE: The purpose of this study was to determine fracture resistance and failure modes of three-unit fixed dental prostheses (FDPs) made of lithium disilicate pressed on zirconia (LZ), monolithic lithium disilicate (ML), and monolithic zirconia (MZ). MATERIALS AND METHODS: Co-Cr alloy three-unit metal FDPs model with maxillary first premolar and first molar abutments was fabricated. Three different FDPs groups, LZ, ML, and MZ, were prepared (n = 5 per group). The three-unit FDPs designs were identical for all specimens and cemented with resin cement on the prepared metal model. The region of pontic in FDPs was given 50,000 times of cyclic preloading at 2 Hz via dental chewing simulator and received a static load until fracture with universal testing machine fixed at 10°. The fracture resistance and mode of failure were recorded. Statistical analyses were performed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni's correction (α=0.05/3=0.017). RESULTS: A significant difference in fracture resistance was found between LZ (4943.87 ± 1243.70 N) and ML (2872.61 ± 658.78 N) groups, as well as between ML and MZ (4948.02 ± 974.51 N) groups (P<.05), but no significant difference was found between LZ and MZ groups (P>.05). With regard to fracture pattern, there were three cases of veneer chipping and two interfacial fractures in LZ group, and complete fracture was observed in all the specimens of ML and MZ groups. CONCLUSION: Compared to monolithic lithium disilicate FDPs, monolithic zirconia FDPs and lithium disilicate glass ceramics pressed on zirconia-based FDPs showed superior fracture resistance while they manifested comparable fracture resistances.
Alloys ; Bicuspid ; Ceramics ; Dental Prosthesis* ; Denture, Partial, Fixed ; Glass ; In Vitro Techniques* ; Lithium* ; Mastication ; Molar ; Resin Cements