To evaluate the efficacy of cryocoagulation as a treatment for cervical intraepithelial neoplasia (C.I.N.), it is necessary to know the maximum depth of the glandular crypts, the maximum crypt involvement by C.I.N. and the extension of the cryolesion, obtained under standardized conditions. In a morphometric study on this subject, one has to take into account the shrinkage of the cervical tissue, caused by processing the tissue for histological examination. In the present study, tissue shrinkage of the cervix in different directions was measured in three separate steps. First shrinkage caused by formalin fixation was determined, second shrinkage caused by dehydration, clearing and paraffin wax embedding and finally that caused by section cutting and mounting. Shrinkage caused by formalin fixation, and by dehydration, clearing and paraffin wax embedding did not differ significantly in the different directions and resulted in an average shrinkage of respectively 2.7% and 12.6% of the original dimensions. The alterations of the dimensions by section cutting and mounting is not a process of shrinkage, but actually a deformation caused by pressure on the tissue during sectioning. Generally the dimension decreases in the cutting direction and increases in the direction perpendicular to it. In the calculation of the total shrinkage these alterations can be neglected, since the changes, although not consistent are small. It follows that in morphometric studies a total shrinkage of about 15% of the original dimensions has to be taken into consideration.
synopsisThe radiation-induced grafting of a series of monomers onto a wide range of paraffin waxes was attempted. Although no grafting could be achieved and only homopolymers were formed, the rates of homopolymerization were greatly enhanced in the presence of the wax. This phenomenon is ascribed to processes of energy transfer from the irradiated wax to the monomer.
ABSTRACT:The presence of a paraffin wax has been found to considerably reduce the radiation dose required to completely polymerize styrene, but no detectable grafting of styrene to wax occurs. The rate of polymerization was found to be greatly dependent on the styrene/wax composition, and the activation energy was determined to be -7.4 kcal/mole. The addition of scavengers indicates a free-radical mechanism which is confirmed by preirradiation experiments, showing the wax to be the main source of initiating radicals. The negative activation energy is explained by an induced gel-effect caused by the semirigid wax matrix, which further enhances the polymerization rate, which cannot be accounted for entirely in terms of increased radical production in the wax.
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