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NITROGEN-OXYGEN SATURATION THERAPY IN DECOMPRESSION SICKNESS
635 than after a single episode of toxin ingestion, as is typical of adult botulism. Antitoxin immunoglobulins of human origin, which could persist for several weeks after administration would be highly desirable, particularly for the treatment of infant botulism.
"Use USN 6 (RN 62) with extra oxygen sessions as needed. Frenchtrained divers also would use 18 m oxygen tables but with a 30 m oxygen-rich option if there is no relief after 15 mins."
The volunteers were United States Army personnel or professionak civilian personnel at the United States Army Medical Research Institute of Infectious Diseases. These tests were governed by the principles, policies, and rules for medical volunteers as established by the Army Regulation 70-25 and the Declaration of Helsinki. The study was conducted as part of a long-term programme for the investigation of mechanisms of vaccine efficacy and host responses to infectious diseases.
Chemical Pathology and Human Metabolism, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton S09 4XY
U.S.A. Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland 21701, U.S.A.
GEORGE E. LEWIS, JR. JOSEPH F. METZGER
CIMETIDINE AND SERUM-PROLACTIN
SIR,-Dr Valcavi and colleagues (Sept. 2, p. 528)
are
prob-
in their assumption that prolactin release in response to cimetidine depends on attaining a sufficiently high blood cimetidine concentration. My colleagues and I have studied two groups of healthy males under fasting and resting conditions.’2 One group received a single oral dose of cimetidine 800 mg whilst the other group was given an intravenous bolus injection of 400 mg. Although basal serum-prolactin concentrations were comparable in both groups, the group receiving cimetidine intravenously experienced a three-fold rise in serum-prolactin in 10-15 min which returned to normal 75-90 min after the injection. In the men taking cimetidine by mouth the serum-prolactin remained unaltered throughout the 4 h of the study. When cimetidine was given intravenously, a mean peak blood concentration (is.E.M.) of 33-5 (±0-3) f-lg/ml was obtained 22 min after the injection; after oral administration the peak 5.55 (±0.2) g/ml occurred after 105 min. The prolactin response to intravenous cimetidine was abolished following pre-treatment with bromocriptine. The blood -concentrations achieved in this study are much larger than those obtained after the administration of conventional therapeutic doses.3 We concluded that, at very high blood concentrations, cimetidine may act directly or indirectly at dopamine receptors in the anterior pituitary to produce hyperprolactinasmia or, perhaps slightly less likely, to inhibit the uptake of prolactin in peripheral tissues.
ably
correct
Smith Kline & French Laboratories Ltd, Welwyn Garden City, Hertfordshire AL7 1EY
D.
ROWLEY-JONES
This oxygen-rich option refers short time at 30 m.
a
to a
40% oxygen mixture and
R.
DE
G. HANSON
AGEING KIDNEY
SIR,-The results of my population studyl would seem to complement Professor McLachlan’s interesting paper (July 15, p. 143), especially in respect of the important question of a decrease in urine concentrating capacity ("ageing"). I investigated 232 male controls and 844 non-pregnant women, aged 21-70, who were free of symptoms at the time of examination. Patients with obstructive uropathy, concretions, diabetes mellitus, possible glomerulonephritis, and other
parenchymal diseases were excluded. The women were divided into four series, uniform with respect to age distribution and maternity: (1) controls with no history of upper or lower urinary-tract infection (u.T.i) and no urinary abnormalities (i.e., neither bacteriuria nor pyuria); (2) women with a history of U.T.I. but no urinary abnormalities at the time of examination ; (3) women with sterile pyuria; and (4) women with bacteriuria/pyuria. About 40% of the women in series 3 and 4 had no history of U.T.I. Maximal urinary concentrating ability, falling with increasing age, was significantly higher in series 1 than in series 2 (difference in intercepts, p
respectively. NITROGEN-OXYGEN SATURATION THERAPY IN DECOMPRESSION SICKNESS .
interested in the article by Dr Miller and others (July 22, p. 169) on the use of nitrogen-oxygen saturation therapy in serious cases of compressed-air decompression sickness. I would be grateful, however, for further clarification on one point. Fig. 1 implies that a mild pain-only bend, which is not seen until more than 5 h have elapsed since onset of symptoms, could possibly end on a saturation table, during the first course of treatment. Is this what Miller et al. advocate, or do they feel that this may be too heroic and the advice given by the European Undersea Biomedical Society in 1976 for the treatment of such cases should be followed:
SIR,-I
was most
After, in most cases, long-term treatment of the bacteriuric series there was significant improvement of the concentration ability, which was sustained during follow-up.2 There thus seems to be a cause-and-effect relationship between reduced maximal concentrating ability and factors such as abnormal urinary findings of sterile pyuria or bacteriuria/pyuria, a history of U.T.I., and a combination of these factors. There was a highly significant age-related increase of the concentrations of serum urea and creatinine in the females (no significant difference between the four series) but there was no significant age trend in the male controls. The levels were significantly higher in the male than in the femal controls (differand p< 0-001, and in regression ences in intercepts, P<0-001 coefficients, P < 0 - 0 and p<0-001, respectively). Health Service of Malmoehus
1.
Burland, W. L., Gleadle, R. I., Lee, R. M., Rowley-Jones, D., Groom, G. V. Br. J clin. Pharmacs. (in the press). 2. Burland, W L., Gleadle, R. I., Lee. R. M., Rowley-Jones, D., Groom, G. V. Br. med. J. 1978, i, 717 3. Longstreth, G. F., Go, V. L. W., Malagelada, J.-R. New Engl. J. Med. 1976, 294, 801.
County District, University Hospital, Lund, Sweden 1. 2.
Alwall, N. Acta med. Scand. 1978, 203, 95. Alwall, N. ibid. p. 369.
NILS ALWALL
"Use USN 6 (RN 62) with extra oxygen sessions as needed. Frenchtrained divers also would use 18 m oxygen tables but with a 30 m oxygen-rich option if there is no relief after 15 mins."
The volunteers were United States Army personnel or professionak civilian personnel at the United States Army Medical Research Institute of Infectious Diseases. These tests were governed by the principles, policies, and rules for medical volunteers as established by the Army Regulation 70-25 and the Declaration of Helsinki. The study was conducted as part of a long-term programme for the investigation of mechanisms of vaccine efficacy and host responses to infectious diseases.
Chemical Pathology and Human Metabolism, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton S09 4XY
U.S.A. Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland 21701, U.S.A.
GEORGE E. LEWIS, JR. JOSEPH F. METZGER
CIMETIDINE AND SERUM-PROLACTIN
SIR,-Dr Valcavi and colleagues (Sept. 2, p. 528)
are
prob-
in their assumption that prolactin release in response to cimetidine depends on attaining a sufficiently high blood cimetidine concentration. My colleagues and I have studied two groups of healthy males under fasting and resting conditions.’2 One group received a single oral dose of cimetidine 800 mg whilst the other group was given an intravenous bolus injection of 400 mg. Although basal serum-prolactin concentrations were comparable in both groups, the group receiving cimetidine intravenously experienced a three-fold rise in serum-prolactin in 10-15 min which returned to normal 75-90 min after the injection. In the men taking cimetidine by mouth the serum-prolactin remained unaltered throughout the 4 h of the study. When cimetidine was given intravenously, a mean peak blood concentration (is.E.M.) of 33-5 (±0-3) f-lg/ml was obtained 22 min after the injection; after oral administration the peak 5.55 (±0.2) g/ml occurred after 105 min. The prolactin response to intravenous cimetidine was abolished following pre-treatment with bromocriptine. The blood -concentrations achieved in this study are much larger than those obtained after the administration of conventional therapeutic doses.3 We concluded that, at very high blood concentrations, cimetidine may act directly or indirectly at dopamine receptors in the anterior pituitary to produce hyperprolactinasmia or, perhaps slightly less likely, to inhibit the uptake of prolactin in peripheral tissues.
ably
correct
Smith Kline & French Laboratories Ltd, Welwyn Garden City, Hertfordshire AL7 1EY
D.
ROWLEY-JONES
This oxygen-rich option refers short time at 30 m.
a
to a
40% oxygen mixture and
R.
DE
G. HANSON
AGEING KIDNEY
SIR,-The results of my population studyl would seem to complement Professor McLachlan’s interesting paper (July 15, p. 143), especially in respect of the important question of a decrease in urine concentrating capacity ("ageing"). I investigated 232 male controls and 844 non-pregnant women, aged 21-70, who were free of symptoms at the time of examination. Patients with obstructive uropathy, concretions, diabetes mellitus, possible glomerulonephritis, and other
parenchymal diseases were excluded. The women were divided into four series, uniform with respect to age distribution and maternity: (1) controls with no history of upper or lower urinary-tract infection (u.T.i) and no urinary abnormalities (i.e., neither bacteriuria nor pyuria); (2) women with a history of U.T.I. but no urinary abnormalities at the time of examination ; (3) women with sterile pyuria; and (4) women with bacteriuria/pyuria. About 40% of the women in series 3 and 4 had no history of U.T.I. Maximal urinary concentrating ability, falling with increasing age, was significantly higher in series 1 than in series 2 (difference in intercepts, p
respectively. NITROGEN-OXYGEN SATURATION THERAPY IN DECOMPRESSION SICKNESS .
interested in the article by Dr Miller and others (July 22, p. 169) on the use of nitrogen-oxygen saturation therapy in serious cases of compressed-air decompression sickness. I would be grateful, however, for further clarification on one point. Fig. 1 implies that a mild pain-only bend, which is not seen until more than 5 h have elapsed since onset of symptoms, could possibly end on a saturation table, during the first course of treatment. Is this what Miller et al. advocate, or do they feel that this may be too heroic and the advice given by the European Undersea Biomedical Society in 1976 for the treatment of such cases should be followed:
SIR,-I
was most
After, in most cases, long-term treatment of the bacteriuric series there was significant improvement of the concentration ability, which was sustained during follow-up.2 There thus seems to be a cause-and-effect relationship between reduced maximal concentrating ability and factors such as abnormal urinary findings of sterile pyuria or bacteriuria/pyuria, a history of U.T.I., and a combination of these factors. There was a highly significant age-related increase of the concentrations of serum urea and creatinine in the females (no significant difference between the four series) but there was no significant age trend in the male controls. The levels were significantly higher in the male than in the femal controls (differand p< 0-001, and in regression ences in intercepts, P<0-001 coefficients, P < 0 - 0 and p<0-001, respectively). Health Service of Malmoehus
1.
Burland, W. L., Gleadle, R. I., Lee, R. M., Rowley-Jones, D., Groom, G. V. Br. J clin. Pharmacs. (in the press). 2. Burland, W L., Gleadle, R. I., Lee. R. M., Rowley-Jones, D., Groom, G. V. Br. med. J. 1978, i, 717 3. Longstreth, G. F., Go, V. L. W., Malagelada, J.-R. New Engl. J. Med. 1976, 294, 801.
County District, University Hospital, Lund, Sweden 1. 2.
Alwall, N. Acta med. Scand. 1978, 203, 95. Alwall, N. ibid. p. 369.
NILS ALWALL