Pretwisting the patellar tendon graft has been advocated hy many authors. Lambert has described a 90 degrees pretwist to benifit the fat pad vascular supply as well as to "" simulate the helicoid course of the ACL "". This technique has also been recommended to fascilitate fixation. Jackson has recommended a 90 pretwist to decrease the possibility of abrasive wear on the tunnel edge, and also to fascilitate fixation as much as a 180 degrees pretwist has heen recommended. However, in spite of all these recommendations, little work has been done on the effect of such pretwisting on the biomechanical behavior of patellar tendon grafts. The purpose of this study is to discover, by experiment, the effects of a 360 degrees external rotation pretwist on the following tensile mechanical properties of canine central 1/3 patellapatellar tendon-tibia complex : (a) ultimate stress, (b) ultimate strain, (c) average elastic modulus, and (d) strain energy density. Five groups of each S specimens were divided as group 1 (0 degrees external rotation), group 2 (90 degrees external rotation). group 3 (180 degrees external rotation), group 4 (270 degreesexternal rotation), and group 5 (360 degrees external rotation). The direction of pretwist meant the twist of tibia around patella. The effects of pretwist were analyzed using parameter one-way analysis of variance (ANOVA)(P1) and nonparameter Kruskal-Wallis one-way analysis of variance (ANOVA)(P2) with repeated measures followed by Scheff multiple comparison test. A p values of < 0.05 was considered statistically significant. Among each groups ultimate stress (P1=0.059, P2=0.095), ultimate strain(P1=0.154, P2=0. l65), and average elastic modulus(P1=0.814, P2=0.818) were not statistically significant. Only strain energy density was the statistically significant difference between group 2 and group 5(P1=0.008, P2=0.022). As a result, there were observed that the ultimate stress and strain energy density were decreased and ultimate strain was decreased but there were not statistically significant differences hetween groups because of the small number of samples, and there will be advantages for graft to avoid ahrasive wear on the tunnel edge and lateral femoral condyle. But, more studies are needed for human being in the future.
Adipose Tissue ; Elastic Modulus ; Humans ; Patella ; Patellar Ligament* ; Tibia ; Transplants

Post-tetanic count(PTC) was a known monitoring method to evaluate intense neuromuscular blockade of peripheral muscles. It has been reported that intermittent tetanic stimulation(50 Hz for 5 sec.) every 6 to 10 min. during intense nondepolarizing neuromuscular blockade did not influence the recovery of neuromuscular transmission. However, the relatively frequent use of tetanic stimulation might be possible to influence the recovery of neuromuscular blockade and the repeated stimuli might result in a false recovery state. The purpose of this study was to determine the best interval time of tetanic stimulation for evaluation of the correct PTC. Sixty adult patients undergoing stomach operations were randomly allocated to three groups according to the interval of tetanic stimulation ; group 1 (6 min. n=20), group 2 (8 min. n=20) and group 3 (10 min. n=20). In all cases, Anesthesia was maintained with 50% nitrous oxide, 50% oxygen and 1-2% enflurane following induction of anesthesia with thiopental sodium 3-5 mg/kg. Neuromuscular block was achieved by intravenous pancuronium bromide 0.13 mg/kg before application of ulnar nerve stimuli using Myotest MKII. The adduction force of the resultant thumb twitch was measured by the acceleration of a small piezo-electric ceramic wafer with electrodes of Mini-accelograph and recorded by Datascope 2200 I After 1 Hz single twitch stimulation, a tetanic stimulus(50 Hz) was applied for 5 sec. Three seconds later, the single twitch stimulation was again applied for 1 min. followed by 1 min. of TOF stimulation. This pattem of tetanic stimulation was continued by the interval of 6, 8 and 10 min. The results were as follows: 1. The continuance (which was the percentage when PTC was continuously increased, not intermittently reduced) was 73.7% in group 1 and 2, but 100% in group 3 and there were statistically significance. 2. In the regression analysis between FI'C and time from PTC1, we yielded the following equations ; Y=10+3.5X (r(2)=0.71) for group 1, Y=8.6+4.1X (r(2)=0.78) for group 2 and Y=9.8+5.7X (r(2)=0.69) for group 3. The slope and intercept of the line of group 3 showed significantly different to that of group 1 and 2 (p<0.001). The more frequent tetanic stimulation reduced the time to arrive the same PTC. 3. The time from PTCl to TOFl was 51.6+/-3.9 min. in group 1, 65+/-5 min. in group 2 and 69+/-4.3 min. in group 3. There were no statistically significance, but they had trend to reduce by more frequent tetanic stimulation. 4. PTC was 12.9+/-0.9 in group 1, 14.9+/-1.5 in group 2 and 13.2+/-0.8 in group 3 when TOF1 was appeared, and 38.3+/-2.3 in group 1, 33.3+/-2.3 in group 2 and 32.4+/-2.6 in group 3 when the second response to TOF stimulation(TOF2) was recorded(meanSEM). There were no statistically significance. With the above results the authors concluded that 10 min. will be the optimal interval of the tetanic stimulation for the correct PTC, and recognized that the interval of tetanic stimulation was not related to the time from PTC1 or PTC at TOF twitches.
Acceleration ; Adult ; Anesthesia ; Ceramics ; Electrodes ; Enflurane ; Humans ; Muscles ; Neuromuscular Blockade ; Nitrous Oxide ; Oxygen ; Pancuronium ; Stomach ; Thiopental ; Thumb ; Ulnar Nerve

No abstract available.
Agaricales* ; Anemia, Aplastic* ; Humans

The effects of pretreatment of Co-Cr alloy, including two adhesive primers that contain either MDP or MAC-10, and silicoating on the bond. The results obtained as follows : Strength of 4-META/MMA-TBB resin were investigated using FT-IR SEM, and EDAX. in the SEM observation of surface morphologies, the sandblasted specimen exibited a very rough surface, whereas the surfaces of the two groups primed with either MDR or MAC-10 were covered with a layer of primer, and the surface morphology of the silicoated specimen remained almost the same after sandblasting. Before the thermocycling tests, the group treated with MDP demonstrated the highest mean tensile bond strength and the sandblasted group showed the lowest bond strength. After 20,000 themocyling, the mean tensile bond strength of the sandblasted group exhibited a 50% reduction in bond strength, while the other showed a 20~30% reduction. Observation of the metal-resin interface revealed that in all groups the resin permeated the rough surface formed by sandblasting thereby producing a mechnical bond between the metal and the resin, It was also found that thermocycling resulted in a gap formation at the metal-resin interface of the specimens, and the sandblasted group exhibited a larger gap width than the other groups. in fracture mode, all specimens indicated a cohesive fracture within the resin before thermocycling. However, thermocyling produced adhesive failure at the edge of the resin-metal interface in most specimens, The sandblasted group, which exhibited the lowest bond strength after thermocycling, also demonstrated the largest area of adhexive failure.
Adhesives ; Alloys*

No abstract available.
Leukemia, Monocytic, Acute* ; P-Glycoprotein*

No abstract available.
Fungemia*

PURPOSE: To assess the efficacy of three-dimensional CT angiography (3D-CTA) using multi-detector row computed tomography (MDCT) in the evaluation of intracranial aneurysms in patients with non-traumatic acute subarachnoid hemorrhage and to describe those aneurysms which were not found 3D-CTA. MATERIALS AND METHODS: 3D-CTA was done in 40 patients with non-traumatic subarachnoid hemorrhage by using a 16-slice MDCT; conventional digital subtraction angiography (DSA) was done in 36 of those patients within 12 hours. The CT and DSA images were reviewed by two radiologists and the site, size and neck of the aneurysms were evaluated. The results from these two modalities were then compared with the operative findings. We calculated the detection rates by 3D-CTA and DSA and evaluated the size differences of aneurysms dignosed with 3D-CTA and those found at surgery. We also analyzed the locations and sizes of aneurysms missed by 3D-CTA and attempted to explain these false negatives. RESULTS: A total of 55 aneurysms were surgically confirmed in 40 patients. 48 of these were detected pre-operatively by 3D-CTA. Thus, the detection rate by 3D-CTA was 87%. The size difference of aneurysms as calculated by 3-D CTA and found operatively was as follows: less than 1 mm in 17 cases, within 1-2 mm in 15 cases, and more than 2 mm in 16 cases. Seven aneurysms were not detected by 3D-CTA. The major cause of these missed aneurysms was their small size. The undetected aneurysms were less than 2 mm in size, except for 2 instances of PCoA aneurysms. One case was not detected due to difficult image evaluation. A possible explanation of the one remaining missed aneurysm was the filling of the aneurismal sac by thrombosis. CONCLUSION: Though there were some limitations in the detection of aneurysms, 3D-CTA using 16-channel MDCT may provide sufficient pre-operative information for the management of patients with intracranial aneurysms in cases of emergency operations or DSA-failure.
Aneurysm ; Angiography ; Angiography, Digital Subtraction ; Emergencies ; Humans ; Intracranial Aneurysm* ; Neck ; Subarachnoid Hemorrhage ; Thrombosis

To estimate the possibility of the application of TiN ion-plating to the orthodontic appliance, colorimetric properties, and characteristics of ion-plated film as well as adhesive strength of TiN film to the substrate and mechanical properties of ion-plated orthodontic appliance were investigated. The obtained results were as follows: 1) TiN ion-plated film had the colorimetric properties which were the hue of about 2.5 Y, the brightness of about 6, and the chroma of about 4 by the standard color chip of JIS. 2) TiN ion-plated film was 2micrometer in thickness and its deposition pattern was rather irregular. 3) TiN phase was confirmed on the X-ray diffraction pattern. 4) Critical load for delamination of ion-plated film from stainless steel band was 10N. 5) Tensile and yield strength of ion-plated specimen was increased about 10Kg,f/mm2 , while elongation was decreased 1% com pairing to the values of the non ion-plated specimen.
Adhesives ; Orthodontic Appliances* ; Stainless Steel ; Tin* ; X-Ray Diffraction

No abstract available.
Parathyroid Neoplasms* ; Radionuclide Imaging* ; Thymoma*

No abstract available.
Pregnancy*