- Email: [email protected]
URINARY OXALATE IN CHRONIC DIALYSIS PATIENTS
48
antigen-binding test against purified cardiac specific antigens). In our indirect immunofluorescent studies, using the technique of Bolte and Schultheiss,2 it became clear that results were subject to considerable method-specific artefacts and observer variation, with inconsistencies in interpretation by independent observers such that no significant difference emerged between test and control groups in the incidence of positivity of these tests. We feel this may account for discrepancies between these and earlier results. Similarly, examination by direct immunofluorescence of cardiac biopsy specimens from patients with congestive cardiomyopathy has been negative in comparison with control biopsies from patients with other cardiac conditions (unpublished). The "gamma-globulin" accumulation apparently bound to the sarcolemmal sheath, as described by Sanders and Rits,3 is in our view non-specific. Lately we have looked at cell-mediated reactions to crude cardiac antigen, the results of which are summarised in the figure. Dextran-sedimented peripheral-blood leucocytes from patients with cardiomyopathy, patients with ischaemic or rheumatic heart-disease, and healthy controls were packed in capillary tubes and cultured for 18 h with and without cardiac antigen. The area of leucocyte migration (A) was measured by planimetry and migration inhibition index calculated from the formula: (A in presence of antigen) - (A in absence of antigen). There is no evidence of significant migration of cardiac antigen in patients with cardiomyopathy,-i.e., no evidence of cardiac-antigen-sensitised lymphocytes in their peripheral blood. While a negative result does not disprove a hypothesis, unless it is consistently negative in several studies, we would urge caution in the interpretation of data from systems prone to artefacts. R. A. THOMPSON T. TRUEMAN M. R. HAENEY M. HATCHETT W. A. LITTLER L. RETIEF
Department of Medicine, University of Birmingham, East Birmingham Hospital,
Birmingham B9 5ST
or to those who use them, and research is going on in the laboratories of C.T.P.A. members and elsewhere under the sponsorship of the Association. At a time when doubts and suspicion of health hazard are being raised about so many chemical and natural materials manufacturers must obtain advice on research priorities. The C.T.P.A. is fortunate to be able to call on Dr F. J. C. Roe for such advice in view of his published work on carcinogenesis and his coeditorship of a comprehensive book on cancer prevention.’ His assessment (Oct. 6, p.744) of the evidence on the safety-in-use of cosmetic talc is not out of line with that expressed in the United States by Food and Drug Administration Commissioner Donald Kennedy in a letter dated Jan. 11, 1979, in reply to a question on the carcinogenicity of talc, sent in by Dr Sidney M. Wolfe and Mr Benjamin Gordon, of the Public Citizen Health Research Group.
Cosmetic Toiletry & 35 Soho Square, London W1V 5DG
Perfumery Association, I. M. PHILLIPSON
URINARY OXALATE IN CHRONIC DIALYSIS PATIENTS SIR,-Caralps et al. found raised values for 24 h urinary oxalate in chronic renal insufficiency. We find this surprising since there is no obvious reason for it and in-vivo observations suggest that endogenous oxalate production would be reduced in chronic renal failure.3,4 We have measured 24 h urinary oxalate in patients with chronic renal failure from various causes. Oxalate was measured by the specific oxalate decarboxy-
lase method.5
The patients had not been given any special advice about oxalate in the diet. We found no evidence for raised urinary oxalate, our normal range being up to 0.5 mmol/24 h (see table). Had we found evidence of hyperoxaluria we would have URINARY OXALATE EXCRETION IN PATIENTS IN RENAL FAILURE
TALC
QUALITY SIR,-Dr Longo and Dr Young (Nov. 10, p. 1011) question the quality of talc used by British cosmetic industry. The Cosmetic, Toiletry and Perfumery Association (C.T.P.A.), formerly the Toilet Preparations Federation, has always been aware of the need to ensure the high quality of talc used by member companies, and a raw-material specification has been in existence since the Association’s earliest days. In 1971 the Association set up a committee to undertake and sponsor research on quality control and safety-in-use. That committee recommended introduction of additional and specific control not just for asbestos but also for asbestos mineral, whether fibrous or not. The recommendation was immediately accepted by the industry, and certified material is available in bulk from the main supply houses. We are perhaps fortunate in Britain in that few grades of talc are used in manufacture of cosmetics and these are imported by a small number of suppliers. Industry has been able to assure itself that these grades are free from contamination, not only by routine quality assurance testing but also by mineralogical survey of producing mines, impurity concentration techniques, electronmicroscopy, X-ray diffraction, energy dispersion analysis, and so on. Our members are well aware of their responsibility to ensure that their products are not hazardous to those who make them 2. Bolte
H-D, Schultheiss P. Immunological Postgrad Med J 1978; 54: 500.
results
in
myocardial diseases.
3. Sanders V, Kits RE. Ventricular localization of bound gamma idiopathic disease of the myocardium. JAMA 1965; 194: 59-61.
globulin
in
For creatinine 1 mmol = 113 mg; for oxalate 1 mmol
=
88 mg.
suspected raised dietary oxalate perhaps exacerbated by low dietary calcium, and have measured urinary glycolate which is usually raised in metabolic hyperoxaluria.6 Perhaps dietary factors explain the raised urinary oxalate observed by Caralps 2 et
al.
St Paul’s Hospital, London WC2
G. P. KASIDAS G. A. ROSE S. SULAIMAN
1. Raven RW, Roe FJC, eds. The prevention of cancer. London: Butterworths, 1967. 2. Caralps A, Llaveras J, Andreu J, Brulles A, Masramon J, Llorach M, Vidal MT, Fernandez Conde M, Aubia J. Urinary glycolate in chronic dialysis patients. Lancet 1979; ii: 1024-25. 3 Wilkinson JH, Fujimoto Y, Senesky D, Ludwig JD. Nature of the inhibitors of lactate dehydrogenase in uraemic dialysates. J Lab Clin Med 1979; 75: 109-19. 4. Fisher V, Watts RWE. The metabolism of glycolate in blood from normal subjects and patients with primary hyperoxaluria. Clin Sci 1978; 34: 97-110. 5. Hallson PC, Rose GA. A simplified and rapid enzymatic method for determination of urinary oxalate. Clin Chim Acta 1974; 55: 29-39. 6. Rose GA, Kasidas GP. A new enzymatic method for measurement of plasma and urinary glycolate and its diagnostic value. In: Vahlensieck W, Gasser G, eds. Proceedings of 6th Harnstein symposium (in press.).
antigen-binding test against purified cardiac specific antigens). In our indirect immunofluorescent studies, using the technique of Bolte and Schultheiss,2 it became clear that results were subject to considerable method-specific artefacts and observer variation, with inconsistencies in interpretation by independent observers such that no significant difference emerged between test and control groups in the incidence of positivity of these tests. We feel this may account for discrepancies between these and earlier results. Similarly, examination by direct immunofluorescence of cardiac biopsy specimens from patients with congestive cardiomyopathy has been negative in comparison with control biopsies from patients with other cardiac conditions (unpublished). The "gamma-globulin" accumulation apparently bound to the sarcolemmal sheath, as described by Sanders and Rits,3 is in our view non-specific. Lately we have looked at cell-mediated reactions to crude cardiac antigen, the results of which are summarised in the figure. Dextran-sedimented peripheral-blood leucocytes from patients with cardiomyopathy, patients with ischaemic or rheumatic heart-disease, and healthy controls were packed in capillary tubes and cultured for 18 h with and without cardiac antigen. The area of leucocyte migration (A) was measured by planimetry and migration inhibition index calculated from the formula: (A in presence of antigen) - (A in absence of antigen). There is no evidence of significant migration of cardiac antigen in patients with cardiomyopathy,-i.e., no evidence of cardiac-antigen-sensitised lymphocytes in their peripheral blood. While a negative result does not disprove a hypothesis, unless it is consistently negative in several studies, we would urge caution in the interpretation of data from systems prone to artefacts. R. A. THOMPSON T. TRUEMAN M. R. HAENEY M. HATCHETT W. A. LITTLER L. RETIEF
Department of Medicine, University of Birmingham, East Birmingham Hospital,
Birmingham B9 5ST
or to those who use them, and research is going on in the laboratories of C.T.P.A. members and elsewhere under the sponsorship of the Association. At a time when doubts and suspicion of health hazard are being raised about so many chemical and natural materials manufacturers must obtain advice on research priorities. The C.T.P.A. is fortunate to be able to call on Dr F. J. C. Roe for such advice in view of his published work on carcinogenesis and his coeditorship of a comprehensive book on cancer prevention.’ His assessment (Oct. 6, p.744) of the evidence on the safety-in-use of cosmetic talc is not out of line with that expressed in the United States by Food and Drug Administration Commissioner Donald Kennedy in a letter dated Jan. 11, 1979, in reply to a question on the carcinogenicity of talc, sent in by Dr Sidney M. Wolfe and Mr Benjamin Gordon, of the Public Citizen Health Research Group.
Cosmetic Toiletry & 35 Soho Square, London W1V 5DG
Perfumery Association, I. M. PHILLIPSON
URINARY OXALATE IN CHRONIC DIALYSIS PATIENTS SIR,-Caralps et al. found raised values for 24 h urinary oxalate in chronic renal insufficiency. We find this surprising since there is no obvious reason for it and in-vivo observations suggest that endogenous oxalate production would be reduced in chronic renal failure.3,4 We have measured 24 h urinary oxalate in patients with chronic renal failure from various causes. Oxalate was measured by the specific oxalate decarboxy-
lase method.5
The patients had not been given any special advice about oxalate in the diet. We found no evidence for raised urinary oxalate, our normal range being up to 0.5 mmol/24 h (see table). Had we found evidence of hyperoxaluria we would have URINARY OXALATE EXCRETION IN PATIENTS IN RENAL FAILURE
TALC
QUALITY SIR,-Dr Longo and Dr Young (Nov. 10, p. 1011) question the quality of talc used by British cosmetic industry. The Cosmetic, Toiletry and Perfumery Association (C.T.P.A.), formerly the Toilet Preparations Federation, has always been aware of the need to ensure the high quality of talc used by member companies, and a raw-material specification has been in existence since the Association’s earliest days. In 1971 the Association set up a committee to undertake and sponsor research on quality control and safety-in-use. That committee recommended introduction of additional and specific control not just for asbestos but also for asbestos mineral, whether fibrous or not. The recommendation was immediately accepted by the industry, and certified material is available in bulk from the main supply houses. We are perhaps fortunate in Britain in that few grades of talc are used in manufacture of cosmetics and these are imported by a small number of suppliers. Industry has been able to assure itself that these grades are free from contamination, not only by routine quality assurance testing but also by mineralogical survey of producing mines, impurity concentration techniques, electronmicroscopy, X-ray diffraction, energy dispersion analysis, and so on. Our members are well aware of their responsibility to ensure that their products are not hazardous to those who make them 2. Bolte
H-D, Schultheiss P. Immunological Postgrad Med J 1978; 54: 500.
results
in
myocardial diseases.
3. Sanders V, Kits RE. Ventricular localization of bound gamma idiopathic disease of the myocardium. JAMA 1965; 194: 59-61.
globulin
in
For creatinine 1 mmol = 113 mg; for oxalate 1 mmol
=
88 mg.
suspected raised dietary oxalate perhaps exacerbated by low dietary calcium, and have measured urinary glycolate which is usually raised in metabolic hyperoxaluria.6 Perhaps dietary factors explain the raised urinary oxalate observed by Caralps 2 et
al.
St Paul’s Hospital, London WC2
G. P. KASIDAS G. A. ROSE S. SULAIMAN
1. Raven RW, Roe FJC, eds. The prevention of cancer. London: Butterworths, 1967. 2. Caralps A, Llaveras J, Andreu J, Brulles A, Masramon J, Llorach M, Vidal MT, Fernandez Conde M, Aubia J. Urinary glycolate in chronic dialysis patients. Lancet 1979; ii: 1024-25. 3 Wilkinson JH, Fujimoto Y, Senesky D, Ludwig JD. Nature of the inhibitors of lactate dehydrogenase in uraemic dialysates. J Lab Clin Med 1979; 75: 109-19. 4. Fisher V, Watts RWE. The metabolism of glycolate in blood from normal subjects and patients with primary hyperoxaluria. Clin Sci 1978; 34: 97-110. 5. Hallson PC, Rose GA. A simplified and rapid enzymatic method for determination of urinary oxalate. Clin Chim Acta 1974; 55: 29-39. 6. Rose GA, Kasidas GP. A new enzymatic method for measurement of plasma and urinary glycolate and its diagnostic value. In: Vahlensieck W, Gasser G, eds. Proceedings of 6th Harnstein symposium (in press.).