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Fat embolism in forensic pathology
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THE R O Y A L COLLEGE OF PATHOLOGISTS OF AUSTRALIA
DIFFERENCE I N SUSCEPTIBILITY TO EXPERIMENTAL I M M U N E GLOMERULONEPHRITIS AMONG RAT STRAINS
MCCAUSLAND, I. P. Departmmt of Pathology, University of Auckland, School of Medicine, New Zealand Rats of Sprague-Dawley and two Wistar strains were injected fortnightly for 100 days with isolated human glomerular basement membrane emulsified in Freund’s adjuvant and then slaughtered. Renal function was monitored by weekly urine protein estimations, and kidneys taken by unilateral nephrectomy and at slaughter were examined by light and electron microscopy and by immunofluorescence. Proteinuria began after 4 wk in Sprague-Dawley rats and continued until slaughter. Glomerular lesions, ranging from focal cellular proliferation and hypertrophy to widespread adhesions and sclerosis, were seen in these rats. By contrast, rats of both Wistar strains failed to develop proteinuria and no glomerular lesions were found. Sections stained with fluorescein-tagged anti-rat IgG antibody revealed intense and consistent linear fluorescence characteristic of anti-glomerular basement membrane antibody along the glomerular capillary walls of Sprague-Dawley rats. Such staining was either weak or absent in the other rats. This observed strain difference in susceptibility to experimental autologous antiglomerular basement membrane antibody glomerulonephritis is thought to be due to genetic variation in the capacity to produce antibody against the introduced foreign glomerular basement membrane. SQUAMOUS PAPILLOMA OF THE CERVIX UTERI
McKE”A, H. Queensland Cytology Service, Royal Women’s Hospital, Brisbane Cytomorphology with clinical, colposcopic and histological confirmation was used to identify squamous papilloma of uterine cervix in 27 patients from 147,813 consecutive cervical smears, an incidence of 15,475. The patients were young women (16-35),63”, of whom were pregnant. When this group was compared with a matched control group, a statistically significant increase in trichomonad infection, and a reduction in fungal infection was observed. There were no false negatives in the series, however 30::, of smears with this pattern were false positives. Smears from every patient with cervical papilloma showed dysplasia of squamous cells which, with one exception, regressed to a lesion of lesser severity, or reverted to normal. The biologic behaviour of the 3 lesions which are described as squamous papilloma differs greatly and cannot be determined by either histology or cytology. Clinico-pathological correlation is necessary for differentiation of the lesion and subsequent management. FAT EMBOLISM I N FORENSIC PATHOLOGY
MASON,J. K. Department of Forensic Medicine, University of Edinburgh Medical School, Scotland The subject of fat embolism must be taken in conjunction with bone marrow embolism and can be considered on anatomical and on clinical grounds. From the forensic aspect, the incidental finding is of major importance as the discovery of pulmonary fat or bone marrow embolism at autopsy should be proof of bone injury having been sustained in life. This hypothesis has been tested by studying 400 aviation fatalities with fracture. The overall incidence of pulmonary fat embolism was 63“,, (37”, of significant degree) and of bone marrow embolism 339,. The Occurrence of both was directly associated with an intact cardiovascular system and with the time taken to die but was inversely related to the degree of bone injury. Fat embolism was found to be a more sensitive index of ante-mortem trauma but bone marrow embolism is a more specific marker of fracture. When correlated with carboxyhaemoglobin levels in those persons exposed to fire, a small number of anomalous cases of embolism of both positive and negative nature were observed. Provided this possibility, and the effect of attempted resuscitation, is taken into account, the use of pulmonary fat embolism as an indicator of ante-mortem trauma is a most valuable tool in forensic pathology. Pulmonary fat embolism is unlikely to be fatal. When the hydrostatic effect of arteriolar blockage results in capillary involvement, the occasionally fatal condition of systemic embolism develops. This is of forensic importance in so far as it must raise the possibility of novus actus interveniens.
THE R O Y A L COLLEGE OF PATHOLOGISTS OF AUSTRALIA
DIFFERENCE I N SUSCEPTIBILITY TO EXPERIMENTAL I M M U N E GLOMERULONEPHRITIS AMONG RAT STRAINS
MCCAUSLAND, I. P. Departmmt of Pathology, University of Auckland, School of Medicine, New Zealand Rats of Sprague-Dawley and two Wistar strains were injected fortnightly for 100 days with isolated human glomerular basement membrane emulsified in Freund’s adjuvant and then slaughtered. Renal function was monitored by weekly urine protein estimations, and kidneys taken by unilateral nephrectomy and at slaughter were examined by light and electron microscopy and by immunofluorescence. Proteinuria began after 4 wk in Sprague-Dawley rats and continued until slaughter. Glomerular lesions, ranging from focal cellular proliferation and hypertrophy to widespread adhesions and sclerosis, were seen in these rats. By contrast, rats of both Wistar strains failed to develop proteinuria and no glomerular lesions were found. Sections stained with fluorescein-tagged anti-rat IgG antibody revealed intense and consistent linear fluorescence characteristic of anti-glomerular basement membrane antibody along the glomerular capillary walls of Sprague-Dawley rats. Such staining was either weak or absent in the other rats. This observed strain difference in susceptibility to experimental autologous antiglomerular basement membrane antibody glomerulonephritis is thought to be due to genetic variation in the capacity to produce antibody against the introduced foreign glomerular basement membrane. SQUAMOUS PAPILLOMA OF THE CERVIX UTERI
McKE”A, H. Queensland Cytology Service, Royal Women’s Hospital, Brisbane Cytomorphology with clinical, colposcopic and histological confirmation was used to identify squamous papilloma of uterine cervix in 27 patients from 147,813 consecutive cervical smears, an incidence of 15,475. The patients were young women (16-35),63”, of whom were pregnant. When this group was compared with a matched control group, a statistically significant increase in trichomonad infection, and a reduction in fungal infection was observed. There were no false negatives in the series, however 30::, of smears with this pattern were false positives. Smears from every patient with cervical papilloma showed dysplasia of squamous cells which, with one exception, regressed to a lesion of lesser severity, or reverted to normal. The biologic behaviour of the 3 lesions which are described as squamous papilloma differs greatly and cannot be determined by either histology or cytology. Clinico-pathological correlation is necessary for differentiation of the lesion and subsequent management. FAT EMBOLISM I N FORENSIC PATHOLOGY
MASON,J. K. Department of Forensic Medicine, University of Edinburgh Medical School, Scotland The subject of fat embolism must be taken in conjunction with bone marrow embolism and can be considered on anatomical and on clinical grounds. From the forensic aspect, the incidental finding is of major importance as the discovery of pulmonary fat or bone marrow embolism at autopsy should be proof of bone injury having been sustained in life. This hypothesis has been tested by studying 400 aviation fatalities with fracture. The overall incidence of pulmonary fat embolism was 63“,, (37”, of significant degree) and of bone marrow embolism 339,. The Occurrence of both was directly associated with an intact cardiovascular system and with the time taken to die but was inversely related to the degree of bone injury. Fat embolism was found to be a more sensitive index of ante-mortem trauma but bone marrow embolism is a more specific marker of fracture. When correlated with carboxyhaemoglobin levels in those persons exposed to fire, a small number of anomalous cases of embolism of both positive and negative nature were observed. Provided this possibility, and the effect of attempted resuscitation, is taken into account, the use of pulmonary fat embolism as an indicator of ante-mortem trauma is a most valuable tool in forensic pathology. Pulmonary fat embolism is unlikely to be fatal. When the hydrostatic effect of arteriolar blockage results in capillary involvement, the occasionally fatal condition of systemic embolism develops. This is of forensic importance in so far as it must raise the possibility of novus actus interveniens.