[Detection of bone fragments in pulmonary vessels following extracorporeal shock wave application to the distal femur in an in-vivo animal model]. / Nachweis von Knochenfragmenten in Lungengefässen nach hochenergetischer Stosswellenapplikation am distalen Femur in einem In-vivo-Tiermodell.

AIM: In urology, single cases of lethal pulmonary embolism following extracorporeal shock wave application to renal concrements have been reported. Therefore, lungs of rabbits were histopathologically investigated following extracorporeal shock wave application to the femur. METHOD: In 8 mature Chinchilla-Bastard rabbits, shock wave application to one distal femur was performed with energy flux density of 0.9 mJ/mm2. In another 6 rabbits, sham-treatment (0 mJ/mm2) to one distal femur was performed. 6 weeks later, the animals were sacrificed and their lungs were blindly investigated by an independent pathologist. RESULTS: In 7 out of the 8 treated animals (0.9 mJ/mm2) but in none of the sham-treated controls, patchy discolorations of the surface of the lung were observed. Furthermore, in 6 out of the 8 treated animals but in none of the sham-treated controls, bony fragments with signs of resorption were observed in lung vessels. CONCLUSION: Application of extracorporeal shock waves with energy flux densities higher than 0.9 mJ/mm2 has been recommended in the literature for the treatment of aseptic non-unions. In this procedure, the possibility of the occurrence of bone fragments in the lung with the potential risk of pulmonary embolism should be regarded.

Conceptual comparison of two computer models of corpuscle sectioning and of two algorithms for correction of ploidy measurements in tissue sections.

OBJECTIVE: To compare two computer models of corpuscle sectioning and two algorithms for correction of ploidy measurements in tissue sections. STUDY DESIGN: Two models of corpuscle sectioning (the computed corpuscle sectioning program [CCSP] [Analyt Quant Cytol Histol 1997;19:376-386] and the ellipsoid sectioning program [ESP]) were run on a personal computer to generate synthetic corpuscle section data that model the sectioned nuclei in a tissue section. These synthetic data were analyzed by two algorithms for correction of ploidy measurements in tissue sections: the reference curve method (RCM) (Analyt Quant Cytol Histol 1997;19:376-386) and the method of McCready and Papadimitriou (MMP) (Analyt Quant Cytol 1983;5:117-123) for a variety of choices of section thickness and of nuclear section profile selection criteria. RESULTS: Previous recommendations (Analyt Quant Cytol Histol 1999;21:103-112) for optimization of ploidy analysis in tissue sections (selection of only center-containing sections of nuclei in ultrathin sections with a selection bias in favor of elliptical nuclear section profiles) are valid regardless of which corpuscle sectioning model and correction algorithm are employed. Perimeter correction may be desirable or necessary in some cases. The RCM has very significant advantages over the MMP, and the CCSP is more applicable to actual ploidy analysis than is the ESP. CONCLUSION: The RCM always should be used to correct ploidy measurements in tissue sections. The MMP should not be used as the sole method but, when used, should be used with and interpreted in the context of the RCM.

Improved correction of quantitative nuclear DNA (ploidy) measurements in tissue sections.

OBJECTIVE: To evaluate, using a computer model, the advantages for ploidy measurements of selecting only center-containing sections of nuclei in ultrathin, very thick or relatively thick tissue sections. STUDY DESIGN: The computed corpuscle sectioning program was run on a personal computer. Its synthetic data were corrected by a variety of correction algorithms. RESULTS: When only center-containing sections of nuclei were selected in ultrathin sections, spherical nuclei could be corrected perfectly, and mildly prolate ellipsoidal nuclei with a selection bias in favor of elliptical nuclear section profiles could be corrected with high fidelity. Ultrathin sections most faithfully represented the true height of the peak of highest ploidy and showed better peak discrimination than other choices of section thickness, but small sample size, wavy sections, markedly inhomogeneous intranuclear DNA distribution and oblate ellipsoidal nuclei represented significant limitations of this approach. As nuclear prolation increased, peak definition worsened, and the peak of highest ploidy was falsely shortened. Results were unaffected by errors in the estimation of section thickness when an internal diploid standard was used. The effect of variable internuclear DNA concentration in mildly or moderately prolate ellipsoidal nuclei was nil. The choice of correction algorithm was unimportant, except that the reference curve method was better able to analyze oblate ellipsoidal nuclei, wavy sections and nuclei with inhomogeneous intranuclear DNA, and provided superior insight into nuclear and section parameters. Thick and very thick sections did not require correction and, unlike ultrathin sections, were immune to markedly inhomogeneous intranuclear DNA distribution, to nonspherical nuclear shape and to focal variation in section thickness (waviness), but (in relatively thick more than in very thick sections) the height of the peak of highest ploidy was falsely shortened, often markedly, and peak definition was worse. CONCLUSION: Choice of section thickness and selection of only center-containing nuclear sections for analysis with a bias in favor of elliptical nuclear section profiles in ultrathin sections are very important for optimal results; the choice of correction algorithm is less important.

Possibility of correcting image cytometric nuclear DNA (ploidy) measurements in tissue sections. Insights from computed corpuscle sectioning and the reference curve method.

OBJECTIVE: To describe, validate and apply a computer simulation of corpuscle sectioning to determine which assumptions are compatible with the possibility of correction. STUDY DESIGN: A computer program was written in PASCAL and run on a personal computer. RESULTS: Correction is practical in the case of spherical nuclei with homogeneous intranuclear DNA and a constant internuclear DNA concentration, even if section thickness is uneven or inaccurate. Correction is not possible in the case of marked nuclear ellipticity: mild cases are correctable, although subpopulations in a mixed-ploidy sample would not be distinguished. Correction is possible in the case of spherical (but not ellipsoidal) nuclei with a variable internuclear DNA concentration, and subpopulations in a mixed-ploidy sample would be distinguishable if sufficiently different. If the DNA is markedly concentrated in one part of the nucleus, overcorrection results. CONCLUSION: The results clarify the factors that limit correction of image cytometric measurements of ploidy in tissue sections. A new method of correcting ploidy measurements in tissue sections is usable.

Hypercoagulability. Should every patient with venous thrombosis be tested?

Tests for anticoagulant protein deficiencies have a low predictive value for venous thrombosis in the general population. Such testing should be done only in patients with recurrent thrombosis, a family history of thrombosis, or atypical features such as young age at presentation or unusual site. Decreased fibrinolysis is another defect often seen in patients with venous thrombosis, but it lacks sufficient specificity to have a high predictive value. The presence of antiphospholipid antibodies has a fairly high predictive value, and testing beyond the partial thromboplastin time may be justified in patients who have (1) arterial thrombosis or (2) a history of fetal demise or recurrent spontaneous abortions.

Desquamative interstitial pneumonia associated with chrysotile asbestos fibres.

The drywall construction trade has in the past been associated with exposure to airborne asbestos fibres. This paper reports a drywall construction worker with 32 years of dust exposure who developed dyspnoea and diminished diffusing capacity, and showed diffuse irregular opacities on chest radiography. He did not respond to treatment with corticosteroids. Open lung biopsy examination showed desquamative interstitial pneumonia. Only a single ferruginous body was seen on frozen section, but tissue examination by electron microscopy showed an extraordinary pulmonary burden of mineral dust with especially high concentrations of chrysotile asbestos fibres. This report emphasises the need to consider asbestos fibre as an agent in the aetiology of desquamative interstitial pneumonia. The coexistent slight interstitial fibrosis present in this case is also considered to have resulted from exposure to mineral dust, particularly ultramicroscopic asbestos fibres.

Pseudomembranous necrotizing bronchial aspergillosis. A variant of invasive aspergillosis in a patient with hemophilia and acquired immune deficiency syndrome.

A 15-yr-old male hemophiliac developed the acquired immune deficiency syndrome (AIDS). His terminal illness was characterized by rapidly progressive respiratory failure with intermittent wheezing, nonresponsive to bronchodilator and steroid therapy. Postmortem examination revealed a pseudomembrane covering the mucosa of the lower trachea and bronchi of both lungs. This pseudomembrane was composed predominantly of fungal hyphae speciated as Aspergillus niger. There was widespread transmural necrotizing bronchitis and fungal invasion that extended to involve a narrow zone of peribronchial tissues. The intervening lung parenchyma was free of fungal disease. This unique form of bronchitis is a distinct variant of invasive aspergillosis and merits recognition because of its clinical and prognostic implications.