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We examined body size, litter size and evidence for Bergmann's and Rensch's rules among eight closely related viviparous Phrynocephalus ( Agamidae) lineages from the Qinghai- Xizang ( Tibetan) Plateau. Mean snout-vent length and (relative) abdomen length was greater in females than males, whereas absolute and relative mean head size, fore - and hindlimb length was larger in males. These patterns suggest that body size may reflect sexual evolutionary conservatism. The lizards are smaller at higher elevations or in colder climates, representing the converse of Bergmann's rule. Absolute differences in female body size among taxa are not equal to the male differences among taxa. This results in a slope less than one when male size is regressed on female size, which allows rejection of Rensch's rule for this group. The female body size elevation-related cline was steeper than the corresponding male cline. Litter sizes were both smaller and less variable at higher elevations. These elevational clines remained after application of phylogenetic comparative methods, indicating that ecological processes play a more important role than phylogeny in shaping patterns of size and reproductive variation in these lizards. It is suggested that seasonal activity and temperature are important environmental factors that contribute to the converse Bergmann's cline, while fecundity selection in females and sex-specific differential-plasticity likely explain why patterns do not conform to Rensch's rule. [ABSTRACT FROM AUTHOR]

This in vitro study aimed to investigate the influence of flowable composite lining with different thicknesses on the marginal quality and internal porosity of Class II composite restorations. Thity-two intact molars, each prepared with two box-only Class II cavities, were randomly divided into four groups: Group 1, P60 filling alone; Group 2, ultrathin flowable composite lining/co-cured with overlaying composite; Group 3, thin lining/pre-cured and Group 4, thick lining/pre-cured. The teeth were then thermocycled for 1500 cycles (between 5 °C and 60 °C) and dye immersed for 24 hours. Exterior surface replicas of these restorations were fabricated before and after thermocyling and examined by SEM to evaluate percentages of the five marginal patterns. Data was statistically evaluated using one-way ANOVA test. The teeth were subsequently sectioned longitudinally. The interface microleakage of cervical margin was measured as to the extent of dye penetration. Internal voids were separately recorded in the cervical interface and the cervical and occlussal halves of the restorations. Mann-Whitney test was applied to analyze the interface microleakage and internal voids. Results revealed that replicas of Group 4 presented the highest percentage of marginal openings both before and after thermocycling in SEM examination. Group 2 exhibited superior marginal quality in interface microleakage evaluation compared to the other groups, while Group 4 exhibited the worst. The pre-cured groups (Group 3 and 4) showed significant reduction in interface and cervical voids. Despite the reduction in interface voids, a thick lining may impair the marginal sealing, especially after thermocycling. It was concluded that a minimally thin flowable composite lining improved cavity adaptation and marginal sealing. [ABSTRACT FROM AUTHOR]

This study determined the influence of a flowable composite lining on marginal microleakage and internal voids in a Class II composite restoration. Forty-eight extracted molars were prepared with Class H cavities and randomly divided into four groups: Group I-Prodigy filling/ Revolution lining; Group H-Prodigy filling only; Group III-Tetric Ceram/Tetric Flow lining; Group IV-Tetric Ceram filling only. After thermocycling tests and dye soaking, these teeth were sectioned longitudinally. Gingival-marginal microleakage and internal voids in three separate portions of the restoration (Interface, Cervical and Occlusal voids) were observed with a stereomicroscope. Results revealed no significant difference in the marginal sealing between pairs with or without the flowable composite lining. Restorations conducted with a flowable composite lining (Groups I and III) exhibited fewer total voids and fewer voids in the interface (p<0.05). However, there was no significant correlation between the number of restoration voids and the associated microleakage. A flowable composite lining in a Class II resin filling could effectively reduce the voids in the interface and the total number of voids in the restoration, but may not necessarily improve marginal sealing. [ABSTRACT FROM AUTHOR]

The distribution pattern of certain monosaccharides in the epithelial cells of the hamster buccal pouch was studied during carcinoma development induced by 9,10-dimethyl-1,2-benzathrancene (DMBA). An avidin-biotin-peroxidase complex (ABC) immunohistochemical technique with high affinity biotinylated lectins was employed to identify monosaccharides. Lectins used in this experiment included Concanavalin A (Con A), for identifying mannose or glucose, Ricinus communis agglutinin I(RCA-I), for identifying galactose, and Ulex europaeus agglutinin I(UEA-I), for identifying fucose. The results show that in normal buccal pouch epithelial cells, fuctose or galactose were concentrated predominantly on the cellular membrane, while mannose and glucose were distributed in the cytoplasm. In the epithelial cells undergoing neoplastic transformation induced by DMBA, most cells showed decreased staining of the above-mentioned monosaccharides, while in other areas the cells were heavily stained. However, the most striking change which occurred was that galactose and fucose shifted from the cellular membrane to the intracytoplasmic area during the malignant transformation. Thus, the changes of anatomic location and intensity of staining of monosaccharides in the buccal pouch epithelium may be used as a criteria for early histochemical diagnosis of malignant transformation. [ABSTRACT FROM AUTHOR]

Proliferating cell nuclear antigen (PCNA) is a nuclear protein synthesized in the late G1 and S phase of the cell cycle which can be detected immunohistochemically in paraffin-embedded tissue as a useful marker for the proliferating fraction of cells in tissue specimens. Thirty-eight cases of oral squamous cell carcinoma were studied in groups according to clinical staging and histological grading (UICC system), these included 5 cases of T1, 13 cases of T2, and 20 cases of T3, and 19 cases of Gl, 12 cases of G2, and 7 cases of G3. The mean percentage of PCNA positively stained tumor cells in this series was 29.2. The mean percentages of PCNA-positive cells in each stage and grade were: T1 (13.7%), T2 (24.4%), and T3 (34.3%); GI (30.5%), G2 (24.8%), and G3 (33.2%). The results indicate that the percentage of PCNA positively stained tumor cells in oral squamous cell carcinoma was significantly greater when tumor size was larger than 2 cm (T1 versus T2/T3). However, there was no significant difference between T2 and T3. There was no correlation between the number of PCNA- stained tumor cells and histological grade. [ABSTRACT FROM AUTHOR]