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A CHEAP DISPOSABLE PIPETTE
575 When iodinated and labelled preparations were made from the 9 batches that had not been discarded on physicochemical grounds, and their catabolic-rate was measured in man, 3 of them showed evidence of grossly inhomogeneous degradation, as indicated by the progressive and striking decrease of the values of the daily catabolic-rate over the entire study, and by rapid degradation of the protein in the first 48 hours after injection. We must conclude that subtle alterations, undetectable by present physicochemical methods, may be induced during the preparation of H.S.A. from plasma. Of course, the adequacy of such batches for therapeutic human use is questionable. H.S.A. manufacturers, besides applying all the available physicochemical methods to screen batches, might adopt the in-vivo catabolic-rate as a standard procedure to detect changes which could reduce the efficiency of the protein. Centre of Nuclear Medicine and National Research Council Group for Clinical Physiology, Medical Clinic, University of Pisa, Italy.
R. BIANCHI G. FEDERIGHI L. DONATO.
UROTERPENOLURIA AND RESISTANT RICKETS
SIR,-Kodicek1 reported abnormal steroids in the urine of patients with vitamin-D-resistant rickets. These abnormal compounds were not present in the urine of healthy persons. We have examined extracts from the urine of a 7-year-old girl with vitamin-D-resistant rickets by thin-layer chromatography. We were unable to find the steroids mentioned by Kodicek, but found a large amount of a substance which we could identify as (+)-p-menthen-l-diol-8,9.2 Among the normal controls (parents and 3 siblings of the patient and 17 healthy children) we found, with 1 exception, a low urinary excretion of the mentioned compound. In 1 child with a so-called brown tumour of the bone the substance was excreted in larger amounts; of 7 infants only 1 with certainty excreted the substance. The same substance has been independently identified in the urine of a 4/2-year-old girl with hirsutism by Wade et al.3 They called the compound uroterpenol. In addition Edwards and Wade reported this, then unknown, substance in the urine of children with congenital adrenal
hyperplasia. p-menthen-diol (uroterpenol) belongs to the cyclic monoterpenes which until now were found only in plants. Apparently it has not been described previously. So far the origin of the substance in man is obscure. It could be the metabolic product of an exogenous monoterpene. Wade et al. reported an increased excretion of uroterpenol after ingestion of aqueous homogenate of whole lemon, which contains limonene,
a
monoterpene closely related to our substance. In our examinations we could not demonstrate a relation between the excretion of uroterpenol and the ingestion of specific foods or drugs. However, we have found large amounts of uroterpenol in the urine of 3 more children with vitamin-D-resistant rickets (the specimens were kindly supplied by Dr. A. Fanconi, Zurich). There is no reason to assume that uroterpenol could be a degradation product of vitamin D. The relation to resistant rickets may be fortuitous, but seems to require further examination. New insights on the aetiology, or new diagnostic possibilities, may result. The diseases in which an increased excretion of uroterpenol have been found seem to have in common the ability to affect bone. K. GELLISSEN. University Children’s Clinic, Bonn. Organic Chemistry Institute, Bonn University. 1.
Ciba Foundation
I. DUPHORN. Bone Structure and
Kodicek, E. Symposium Metabolism; p. 201. London, 1956. 2. Tschesche, R., Duphorn, I., Gellissen, K. Hoppe-Seyler’s Z. physiol. Chem. 1966, 345, 100. 3. Wade, A. P., Wilkinson, G. S., Dean, F. M., Price, A. W. Biochem. J. 1966, 101, 727. 4. Edwards, R. W. H., Wade, A. P. J. Endocr. 1965, 33, 153. on
DIURETIC-INDUCED HYPERKALÆMIA SIR,-The letter from Dr. Knight and Dr. Parkinson (Feb. 25, p. 446) shows that certain diuretics, particularly when used concomitantly over long periods, can interfere with the renal excretion of potassium. There is one aspect of the situation, on which your correspondents do not remark, which I feel calls for some comment. Before coming under their care in hospital their patient had had no less than 15 months’ continuous treatment with
spironolactone, triamterene, and benzthiazide, apparently without appropriate monitoring of serum-electrolytes. The latter two diuretics, in the dosage described, are most unlikely to give rise to hyperkal2emia when used concurrently, unless the situation be complicated by the administration of dietary potassium supplements or by further interference with potassium excretion (e.g. by renal disease or spironolactone). The four patients referred to by Cohen in the paper1 cited by Dr. Knight and Dr. Parkinson were diabetics, one of whom had a nephropathy with uraemia and was receiving hydrochlorothiazide, spironolactone, and triamterene simultaneously. Of the others, one, who was taking triamterene and hydrochlorothiazide, had had a nephrectomy. The remaining two patients were taking triamterene alone, and we are not told whether or not potassium supplements were being given. Dr. Knight and Dr. Parkinson rightly point out that the danger of hyperkalmmia in diuretic therapy is rare. I feel that selective use of powerful diuretics and the careful monitoring of long-term treatment would make it rarer. Research Institute, French Laboratories, Ltd., Garden City, Hertfordshire.
Smith Kline &
Welwyn
J. C. P. WEBER.
A CHEAP DISPOSABLE PIPETTE SIR,-1 introduced drinking-straw pipettes into this laboratory about eight years ago. It was not an original idea but was derived from a paper by Tarshis, of which I have long forgotten the reference. Dr. R. E. Davis (March 4, p. 513) described the use of these pipettes in haematology. In a microbiological laboratory it is necessary to plug the straws with cotton-wool. They should be sterilised in an autoclave. They are easier to use if the distal ends are flattened. Glass adaptor nozzles can be made in the form of a very short pasteur pipette with a long taper which is fitted into the straw above the wool plug. These straws are used extensively for inoculating sputum concentrates on culture slopes, spreading lawns of Staphylococcus pyogenes for ’phage-typing, and changing the medium in tissue-culture tubes in the virus laboratory. They can be used for most of the purposes for which glass pasteur pipettes are used and they are infinitely cheaper. A drinking-straw pipette makes a useful taper for lighting one bunsen burner from another. Public Health Laboratory, Royal Hampshire County Hospital, M. H. HUGHES. Winchester.
HYPERTENSIVE ANGIOPATHY IN FAMILIAL CHLORIDE DIARRHŒA SIR,-Dr. Pasternack and Dr. Perheentupa, in their interesting article,2 draw attention to the presence of pronounced vascular changes in the absence of hypertension in the kidneys of their subjects. I should like to point out that the same phenomenon was found in the patient we described in 1960 in a paper entitled " Severe Potassium Depletion Caused by the Abuse of Laxatives ".3 Of course the clinical picture of these patients has many features in common, such as dehydration, potassium depletion, and chloride deficiency. One may well wonder whether it is permissible to ascribe the vascular changes to one factor only-high angiotensin activity-as stated by 1. Cohen, A. B. Ann. intern. Med. 1966, 65, 522. 2. Pasternack, A., Perheentupa, J. Lancet, 1966, ii, 1047. 3. de Graeff, J., Schuurs, M. A. M. Acta med. scand. 1960, 166, 407.
R. BIANCHI G. FEDERIGHI L. DONATO.
UROTERPENOLURIA AND RESISTANT RICKETS
SIR,-Kodicek1 reported abnormal steroids in the urine of patients with vitamin-D-resistant rickets. These abnormal compounds were not present in the urine of healthy persons. We have examined extracts from the urine of a 7-year-old girl with vitamin-D-resistant rickets by thin-layer chromatography. We were unable to find the steroids mentioned by Kodicek, but found a large amount of a substance which we could identify as (+)-p-menthen-l-diol-8,9.2 Among the normal controls (parents and 3 siblings of the patient and 17 healthy children) we found, with 1 exception, a low urinary excretion of the mentioned compound. In 1 child with a so-called brown tumour of the bone the substance was excreted in larger amounts; of 7 infants only 1 with certainty excreted the substance. The same substance has been independently identified in the urine of a 4/2-year-old girl with hirsutism by Wade et al.3 They called the compound uroterpenol. In addition Edwards and Wade reported this, then unknown, substance in the urine of children with congenital adrenal
hyperplasia. p-menthen-diol (uroterpenol) belongs to the cyclic monoterpenes which until now were found only in plants. Apparently it has not been described previously. So far the origin of the substance in man is obscure. It could be the metabolic product of an exogenous monoterpene. Wade et al. reported an increased excretion of uroterpenol after ingestion of aqueous homogenate of whole lemon, which contains limonene,
a
monoterpene closely related to our substance. In our examinations we could not demonstrate a relation between the excretion of uroterpenol and the ingestion of specific foods or drugs. However, we have found large amounts of uroterpenol in the urine of 3 more children with vitamin-D-resistant rickets (the specimens were kindly supplied by Dr. A. Fanconi, Zurich). There is no reason to assume that uroterpenol could be a degradation product of vitamin D. The relation to resistant rickets may be fortuitous, but seems to require further examination. New insights on the aetiology, or new diagnostic possibilities, may result. The diseases in which an increased excretion of uroterpenol have been found seem to have in common the ability to affect bone. K. GELLISSEN. University Children’s Clinic, Bonn. Organic Chemistry Institute, Bonn University. 1.
Ciba Foundation
I. DUPHORN. Bone Structure and
Kodicek, E. Symposium Metabolism; p. 201. London, 1956. 2. Tschesche, R., Duphorn, I., Gellissen, K. Hoppe-Seyler’s Z. physiol. Chem. 1966, 345, 100. 3. Wade, A. P., Wilkinson, G. S., Dean, F. M., Price, A. W. Biochem. J. 1966, 101, 727. 4. Edwards, R. W. H., Wade, A. P. J. Endocr. 1965, 33, 153. on
DIURETIC-INDUCED HYPERKALÆMIA SIR,-The letter from Dr. Knight and Dr. Parkinson (Feb. 25, p. 446) shows that certain diuretics, particularly when used concomitantly over long periods, can interfere with the renal excretion of potassium. There is one aspect of the situation, on which your correspondents do not remark, which I feel calls for some comment. Before coming under their care in hospital their patient had had no less than 15 months’ continuous treatment with
spironolactone, triamterene, and benzthiazide, apparently without appropriate monitoring of serum-electrolytes. The latter two diuretics, in the dosage described, are most unlikely to give rise to hyperkal2emia when used concurrently, unless the situation be complicated by the administration of dietary potassium supplements or by further interference with potassium excretion (e.g. by renal disease or spironolactone). The four patients referred to by Cohen in the paper1 cited by Dr. Knight and Dr. Parkinson were diabetics, one of whom had a nephropathy with uraemia and was receiving hydrochlorothiazide, spironolactone, and triamterene simultaneously. Of the others, one, who was taking triamterene and hydrochlorothiazide, had had a nephrectomy. The remaining two patients were taking triamterene alone, and we are not told whether or not potassium supplements were being given. Dr. Knight and Dr. Parkinson rightly point out that the danger of hyperkalmmia in diuretic therapy is rare. I feel that selective use of powerful diuretics and the careful monitoring of long-term treatment would make it rarer. Research Institute, French Laboratories, Ltd., Garden City, Hertfordshire.
Smith Kline &
Welwyn
J. C. P. WEBER.
A CHEAP DISPOSABLE PIPETTE SIR,-1 introduced drinking-straw pipettes into this laboratory about eight years ago. It was not an original idea but was derived from a paper by Tarshis, of which I have long forgotten the reference. Dr. R. E. Davis (March 4, p. 513) described the use of these pipettes in haematology. In a microbiological laboratory it is necessary to plug the straws with cotton-wool. They should be sterilised in an autoclave. They are easier to use if the distal ends are flattened. Glass adaptor nozzles can be made in the form of a very short pasteur pipette with a long taper which is fitted into the straw above the wool plug. These straws are used extensively for inoculating sputum concentrates on culture slopes, spreading lawns of Staphylococcus pyogenes for ’phage-typing, and changing the medium in tissue-culture tubes in the virus laboratory. They can be used for most of the purposes for which glass pasteur pipettes are used and they are infinitely cheaper. A drinking-straw pipette makes a useful taper for lighting one bunsen burner from another. Public Health Laboratory, Royal Hampshire County Hospital, M. H. HUGHES. Winchester.
HYPERTENSIVE ANGIOPATHY IN FAMILIAL CHLORIDE DIARRHŒA SIR,-Dr. Pasternack and Dr. Perheentupa, in their interesting article,2 draw attention to the presence of pronounced vascular changes in the absence of hypertension in the kidneys of their subjects. I should like to point out that the same phenomenon was found in the patient we described in 1960 in a paper entitled " Severe Potassium Depletion Caused by the Abuse of Laxatives ".3 Of course the clinical picture of these patients has many features in common, such as dehydration, potassium depletion, and chloride deficiency. One may well wonder whether it is permissible to ascribe the vascular changes to one factor only-high angiotensin activity-as stated by 1. Cohen, A. B. Ann. intern. Med. 1966, 65, 522. 2. Pasternack, A., Perheentupa, J. Lancet, 1966, ii, 1047. 3. de Graeff, J., Schuurs, M. A. M. Acta med. scand. 1960, 166, 407.