In Denmark, porcine kidneys displaying macroscopic lesions of mycotoxic nephropathy are analysed for Ochratoxin A and the carcass condemned if the concentration exceeds 25 micrograms/kg. Since late 1982 these analyses have been conducted centrally. The reliability of the one-dimensional thin layer chromatographic method is discussed and results from an interlaboratory comparison are presented. From 1980 to 1984 there has been an overall decline in the rate of ochratoxicosis, interrupted in 1983 by a major increase geographically located in the northern half of Jutland. During that year 7639 kidneys were examined; 3% contained more than 150 micrograms/kg and 29% more than 25 micrograms/kg Ochratoxin A, corresponding to a condemnation rate of 15 per 100 000 slaughterings. The early stage of the increased incidence was characterized by kidneys with extremely high levels of the toxin; later most of the samples were negative or near-negative, as affected pigs were presumably fed a toxin-free diet before slaughtering. The efficacy of the control program is discussed in view of the 1983 data.
The role of the autopsy is discussed in the study of the etiology of the current major causes of death (cardiovascular and neoplastic diseases) in developed countries. Evidence is accumulating for the importance of environmental factors in the etiology of these diseases. The study of regional differences in occurrence is described as a method of identifying specific factors. Maps are shown of mortality rates for all causes of death in Ontario counties for males aged 65-74 and 95+ during 1964-68. Some of the difficulties in obtaining data in this form, and in their analysis, are indicated. Regional mortality patterns can be interpreted by the use of associations with available regional socioeconomic measures, or by the use of regional data on trace-metal levels in autopsy samples of human lung, rib, vertebra, kidney and liver. The methodology and the difficulties involved in the determination of trace-metal levels in these tissues are discussed, as is the possible relevance of these levels to the study of degenerative diseases. All these considerations emphasize the valuable contributions of autopsy studies.
The cadmium concentration of renal tissue from 82 patients who had died at the age of 45-65 years has been determined by atomic absorption spectrophotometry; 43 were normotensive and 39 hypertensive. Renal cadmium concentration was higher in normotensives than in hypertensives. When smoking habits were taken into account, renal cadmium concentration was found to be 82% higher in normotensives than in hypertensives. Other workers have found the opposite relationship. It is proposed that this discrepancy might reflect either that variations due to age were not taken into account in previous investigations or that a difference exists between soft-water areas and hard-water areas such as the one studied.
The content of cadmium and selenium in horse kidneys from Jutland , Denmark, in relation to age, local geographical variation and possible relationship between the two elements has been investigated. During the winter of 1982-1983 kidneys from 50 horses were sampled and analysed for cadmium and selenium. The cadmium content of the horse kidneys was recorded in connection with the age of the horses. The cadmium level increases until the animal has reached approximately 7 years of age. At this age the cadmium concentration levels off. A significant regional difference was shown. The cadmium content is higher in horse kidneys from South and Central Jutland than in kidneys from North Jutland (Fig. 2). This geographic pattern is consistent with the one for atmospheric deposition of cadmium and cadmium content in Danish cattle kidneys from Jutland . The cadmium level in kidneys from Danish horses is considerably lower than the level in Norwegian and Swedish horse kidneys. Differences in water hardness and atmospheric deposition may explain some of this difference within Scandinavian countries. The selenium concentration shows no relationship with neither age, cadmium content nor place of rearing. So, the study did not reveal any relationship between the cadmium and selenium concentrations in horse kidneys. The high level of cadmium found in Danish horse kidneys emphasizes the importance of a prohibition against the use of the kidneys in animal and human nutrition, as proposed by others.
Autoimmune tubulointerstitial nephritis was induced in Brown-Norway (BN) rats by immunization with bovine (Bov) tubular basement membrane (TBM) in complete Freund's adjuvant. Serum antibodies thus produced reacted to a greater extent with Bov than BN TBM antigens by indirect immunofluorescence and by radioimmunoassay with particulate (P) and collagenase-solubilized (CS) TBM. The quantities of antibodies reactive with CS TBM correlated with the intensity of tubulointerstitial pathologic changes. Antibodies eluted from kidneys reactive with BN TBM by indirect immunofluorescence were 508 times more concentrated in the kidney than in the serum, compared with 15 times for Bov TBM-reactive antibodies. The reactivity of eluted antibodies to P BN TBM was inhibited by 70% after absorption with BN CS TBM. A major CS TBM antigen of 42,000 m.w. was identified by polyacrylamide gel electrophoresis. This antigen was present in both Bov and BN TBM, and may be important in triggering autoantibody formation in this model. Lewis rats immunized under the same conditions produced antibodies reactive with BN TBM by immunofluorescence but failed to develop immune deposits in TBM of their own kidneys. Analysis of serum anti-TBM antibodies in Lewis rats revealed a selective lack of reactivity with either homologous or autologous CS TBM. These results suggest that the ability to make an immune response to one or more elements of CS TBM plays a major role in the development of autoimmune tubulointerstitial nephritis in rats.