SUMMARY
The fractionator is illustrated by means of a biomedical example involving the estimation of the number of lymphatic valves in lungs of infants who had died from sudden infant death syndrome (SIDS) and other known causes.
The method is unbiased irrespective of tissue deformations and it does not require external information such as section thickness. An upper bound of the coefficient of error of the estimate of the number of valves within one lung was 6.5%, despite the fact that the number of valves counted per lung at the last stage ranged between 11 and 37 only. The upper bound includes the biological variation of the number of valves among infant lungs.
Some theoretical remarks are also made on the efficiency of the fractionator. It is suggested, for instance, that the initial sampling stages cause more impact on the precision of the final estimator than the subsequent stages, and that an optimal arrangement of fragments submitted to systematic sampling should have the smallest fragments at the ends, with fragment contents increasing smoothly toward the middle of the series.
A case of sudden death due to recurrent pulmonary thromboembolism is described. The fatality took place three and a half weeks following blunt trauma to the left popliteal region. The patient died unexpectedly. Autopsy revealed the source of the emboli as a sacciform venous aneurysm of the popliteal vein, an entity seldom described, but important to consider in cases of soft tissue popliteal masses or unexplained pulmonary embolism, especially in otherwise healthy individuals.
For the first time, a case is described in which an unknown corpse is identified by the comparison of antemortem and postmortem computed tomographic (CT) images. A posterolateral disc herniation at L5-S1 on the right side, Schmorl's nodes and a lucency in the ilium were found in identical locations in each case. Additionally there were characteristic morphological similarities in the vertebral bodies, spinous processes, transverse processes and neural arches. In CT identification, as in conventional radiographic identification, one must try to reproduce comparable scanning conditions and images because apparent differences in the roentgenological morphology can occur as a result of different gantry angles or slice thicknesses.
The industrial dye Solophenyl Red 3 BL (Ciba-Geigy) dissolved in a saturated aquaeous solution of picric acid has proved suitable for differentiating between collagen types I and III in histological sections. When examined under polarization microscopy, type I fibers are radiant orange while type III fibers are green. Using 5 micron paraffin sections, an optimal staining procedure was determined: sections were first stained with Resorcin Fuchsin for elastic fibers and with Celestin Blue/Mayer's Hematoxylin for nuclear structures. The staining was then completed with 0.1 g Solophenyl Red/100 ml saturated aqueous solution of picric acid for 60 min at a pH value of 1.25. It was shown that the dye stained collagen selectively. With the aid of a photomultiplier, the spectral distribution of a series of lung sections adequately stained according to the optimized procedure was carried out using a monochromator and an interference filter, respectively. Both methods yielded identical peaks at 590 nm for the orange colored light of collagen type I and 490 nm for the green light of collagen type III. Application of appropriate filters permitted the intensity of the orange and green light at 590 nm and 490 nm to be measured. Long postmortem intervals did not affect the measured values. Quantitative inferences on the ratio of collagen I to collagen III could then be deduced from the ratio of the intensity of orange to green light. This index I/III is often applied in the diagnosis of discrete fibrotic changes in various organs.
Chemical Stripping of the urinary bladder mucosa was studied in 38 cats using 5 to 25% formaldehyde solutions. The contact time varied from 1 to 20 min. With a 20% solution and contact time of 1 min, total denudation was possible without necrosis of subepithelial layers. In such cases, complete reepithelialisation and normal bladder dynamics were seen within 3-4 weeks after formaldehyde instillation. Signs of formaldehyde intoxication due to vesical resorption were not observed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.