Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isoenzyme patterns from 69 (men, 47; women, 22) surgical colon mucosal specimens were identified by agarose isoelectric focusing. gamma-ADH was found to be the predominant form in the mucosa, whereas only beta-ADH was detectable in the muscle layer. ALDH1, ALDH2, and ALDH3 were detectable in the mucosa, with cytosolic ALDH1 being the major form. At pH 7.5, the ADH activities in the colon mucosae with the homozygous phenotype (exhibiting gamma 1 gamma 1) and the heterozygous phenotype (exhibiting gamma 1 gamma 1, gamma 1, gamma 2, gamma 2, gamma 2) were determined to be 183 +/- 13 and 156 +/- 30 nmol/min/g tissue, respectively. The ALDH activities in the ALDH2-active and ALDH2-inactive phenotypes were determined to be 40.2 +/- 2.3 and 34.6 +/- 2.0 nmol/min/g tissue, respectively. The lack of significant difference in the ALDH activities between these two phenotypic groups can be attributed to the very low expression of the mitochondrial ALDH2 in the colon mucosa. No significant differences in the ADH or the ALDH activities were found between the men and women studied and between the three age groups (20-40, 49-70, and 72-83 years). The ascending, transverse, descending, and sigmoid colons exhibited similar ADH and ALDH activities. The isoenzyme patterns of ADH and ALDH remained unaltered in colon carcinomas, except that a significant reduction of the enzyme activities was found in the cancer tissue as compared with the adjacent normal portions. it is concluded that human colon mucosa exhibits significant amounts of ethanol- and acetaldehyde-oxidizing activities.
Reproduction of the exact interocclusal relationship using digital workflow is crucial for precise fabrication of accurate prostheses. Intraoral scanner is known to be valid for the measurement of quadrants, however, the role of missing area in the quadrant scan on the virtual interocclusal record (VIR) is uncertain. This study aimed to evaluate the accuracy of VIR in quadrant scans using an intraoral scanner (IOS) under four different edentulous conditions. Eight scans per group were obtained using a laboratory scanner and three IOSs (Trios3, CS3600, i500). Based on trueness and precision, Trios3 had the best results, followed by CS3600 and i500. The trueness and precision were affected by edentulous conditions. The three IOSs showed deviation in the posterior region during assessment of VIR for the missing area with posterior support. CS3600 and i500 showed deviation in the short-span edentulous area without support. In extended edentulous condition without support, Trios3 showed overclosure, while i500 showed an angular deviation. In some groups scanned with Trios3 and i500, the tilting effect was observed. Based on the edentulous condition and type of IOS used, local or general deviations in occlusion were seen. The accuracy of VIR was dependent on accurate scan data. Thus, registration of the occlusal relationship in an edentulous area with more than two missing teeth using IOSs may be clinically more inaccurate than that with a laboratory scanner.
Recently, digital technology has been used in dentistry to enhance accuracy and to reduce operative time. Due to advances in digital technology, the integration of individual mandibular motion into the mapping of the occlusal surface is being attempted. The Patient Specific Motion (PSM) is one such method. However, it is not clear whether the occlusal design that is adjusted using PSM could clinically show reduced occlusal error compared to conventional methods based on static occlusion. In this clinical comparative study including fifteen patients with a single posterior zirconia crown treatment, the occlusal surface after a clinical adjustment was compared to no adjustment (NA; design based on static occlusion), PSM (adjusted using PSM), and adjustment using a semi-adjustable articulator (SA) for the assessment of occlusal error. The root mean square (RMS; μm), average deviation value (±AVG; μm), and proportion inside the tolerance (in Tol; %) were calculated using the entire, subdivided occlusal surface and the out of tolerance area. Using a one-way ANOVA, the RMS and +AVG from the out of tolerance area showed a statistical difference between PSM (202.3 ± 39.8 for RMS, 173.1 ± 31.3 for +AVG) and NA (257.0 ± 73.9 for RMS, 210.9 ± 48.6 for +AVG). For the entire and subdivided occlusal surfaces, there were no significant differences. In the color-coded map analysis, PSM demonstrated a reduced occlusal error compared to NA. In conclusion, adjustment occlusal design using PSM is a simple and effective method for reducing occlusal errors that are difficult to identify in a current computer-aided design (CAD) workflow with static occlusion.
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