- Email: [email protected]
β-THROMBOGLOBULIN LEVELS AND ORAL CONTRACEPTION
631 advocated the alternative ean
use
of regional anaesthesia for
Coroner’s Court, Birmingham B4 6NE
R. M. WHITTINGTON
Department of Anæsthetics, University of Birmingham, Queen Elizabeth Hospital,
J. S. ROBINSON JOHN M. THOMPSON
Birmingham B15 2TH
ACTUAL OR STANDARD BICARBONATE
caesar-
section.
SiR,-Mr Lawrie and Mr Golda (July 28, p. 201) report on methods of providing the clinician with information about metabolic acidosis. Clinicians’ preference for base excess might have been anticipated; at least base excess purports to measure the metabolic acidosis. However, it is regrettable that we still measure acidosis as negative base.
&bgr;-THROMBOGLOBULIN LEVELS AND ORAL CONTRACEPTION
SIR,-Dr Aranda and colleagues (Aug. 11, p. 308) report increased
p-thromboglobulin (p-TG)
values in In
women
taking
a
similar study, we measured &bgr;-TG in the blood of 30 women taking various contraceptive pills with an oestrogen content of 20-100 p.g and compared these with values in 29 age-matched healthy women. We do not use venous stasis for sample collection.
particular oral-contraceptive preparation.
a
p-TG value found in the controls was 16+6-7 while the mean value in our contraceptive group was 37±27-5 ng/ml (p<0.01). Despite the differences in actual and both Aranda’s ours recorded increases of values, study 2’3xnormal in women taking oral contraceptives. No correlation (r=0-28) was found between p-TG levels and the oestrogen content of the contraceptive pills in our-study. Both studies are at variance with the report from Ludlam et al.l who found no such elevation. The
mean
(SD) ng/ml
Like Aranda et al. we used the Amersham radioimmunoassay kit, but in our assay, instead of the sample tubes supplied by the manufacturer, we used tubes containing the mixture of
EDTA, theophylline, and prostaglandin EI.2 We have found that our normal values for &bgr;- TG, although similar to the original values of Ludlam et al.’ (19+0.75 ng/ml), are lower than those published by other groups2-4 who use the Amersham kit without modification. Reference to the different values of p-TG levels found by using these two different sample tubes has already been made in a Lancet editorial.5 In our assay, 95% of all values in our control group were less than 30 ng/ml. On the other hand, the normal values detected by Aranda’s group (41+20 ng/ml) are higher than most published values. 1-4 Total sample-to-assay time was 45 min in Aranda’s study, which is less than that recommended by Ludlam and Cash2 and by the kit manufacturer. If insufficient time were allowed for cooling on ice/water, 0-4°C (at least 30 min according to K. Kabareck of the Radiochemical Centre, Amersham) before 30 min centrifugation, this could account for the generally high values that Aranda et al. found.
conflicting results are similar to reports in the literaindicating both normal6 and abnormal4,7 levels of p-TG in similar groups of diabetic patients; perhaps the discrepant results of p-TG studies on diabetics and women on oral contraceptives can be explained by differences in sample acquisition and handling. These
ture
Department of Pathology, Mayo Clinic, Rochester, Minnesota 55901,
U.S.A.
ALEXANDER DUNCAN
CA, Moore S, Bolton AE, Pepper DS, Cash JD. Thromb Res 1975; 6: 543-48. 2. Ludlam CA, Cash JD. Br J Hœmatol 1976; 39: 239-47. 3 Broughton BJ, Allington MD, King A. Br J Hæmatol 1978; 40: 125-32. 4 Burrows AW, Chavin SI, Hockaday TDR. Lancet 1978; i: 235-37. 5. Lancet 1978; i: 250. 6. Campbell IN, Dawes J, Fraser DM, Pepper DS, Clark B, Cash JD. Diabetes 1. Ludlam
t’LU2 In-vivo acid-base bances.
diagram showing
location of chronic distur-
accompanying diagram is an updated version of one published three years ago. The intersection of PC02 and pH The
allows the metabolic disturbance to be read from the Y-axis in mmol/1. It is easier to comprehend mmol/1 of metabolic acidosis (or alkalosis) than to grapple with negative (or positive) base excess. This diagram positions chronic respiratory and metabolic conditions where intuition would place them-midway between total compensation and no compensation (i.e., either midway between pH 7-4 and pure respiratory disturbance [the zero line] or midway between pH 7-4 and pure metabolic disturbance [the PC02 S-33 line]). Clinical educational experience with this diagram suggests it to be a representation with some advantages, not the least of which is that it avoids base excess, standard bicarbonate, and actual bicarbonate. Department of Anesthesiology, Upstate Medical Center, Syracuse, New York 13210, U.S.A.
A. W. GROGONO
ARE THERE ANTIGENIC VARIANTS OF HEPATITIS A VIRUS?
SIR,-Hepatitis B virus has several serological subtypes of its surface antigen, but hepatitis A virus (HAV) is considered to be serologically uniform. Our findings make this view of HAV questionable. In experiments to standardise a solid-phase radioimmunoassay (SPIRA) for HAV and virus-specific antibodies immune serum gammaglobulin from the HAVAb kit of Abbott (IGUSA) and gammaglobulin prepared from a pool of convalescent sera (IG-USSR) were used. The sources of virus samples were faeces from hepatitis A patients in Moscow (F375-Moscow) ; Central Asia (F245-CA); West Germany (FD-FRG), kindly provided by Prof. F. Deinhardt and Dr G. Frosner; and Bulgaria (FBA-PRB), kindly supplied by Dr M. Teokharova. SPIRA tests revealed HA antigen in F375-Moscow and
1977; 26: 1175-77. 7. Preston FE, Ward JD, Marcola BH, Porter NR, BC. Lancet 1978; i: 238-41.
Timperley WR, O’Malley
1.
Grogono AW, Byles PH,
Hawke W. An in-vivo representation of acid-base balance. Lancet 1976; ii: 499.
use
of regional anaesthesia for
Coroner’s Court, Birmingham B4 6NE
R. M. WHITTINGTON
Department of Anæsthetics, University of Birmingham, Queen Elizabeth Hospital,
J. S. ROBINSON JOHN M. THOMPSON
Birmingham B15 2TH
ACTUAL OR STANDARD BICARBONATE
caesar-
section.
SiR,-Mr Lawrie and Mr Golda (July 28, p. 201) report on methods of providing the clinician with information about metabolic acidosis. Clinicians’ preference for base excess might have been anticipated; at least base excess purports to measure the metabolic acidosis. However, it is regrettable that we still measure acidosis as negative base.
&bgr;-THROMBOGLOBULIN LEVELS AND ORAL CONTRACEPTION
SIR,-Dr Aranda and colleagues (Aug. 11, p. 308) report increased
p-thromboglobulin (p-TG)
values in In
women
taking
a
similar study, we measured &bgr;-TG in the blood of 30 women taking various contraceptive pills with an oestrogen content of 20-100 p.g and compared these with values in 29 age-matched healthy women. We do not use venous stasis for sample collection.
particular oral-contraceptive preparation.
a
p-TG value found in the controls was 16+6-7 while the mean value in our contraceptive group was 37±27-5 ng/ml (p<0.01). Despite the differences in actual and both Aranda’s ours recorded increases of values, study 2’3xnormal in women taking oral contraceptives. No correlation (r=0-28) was found between p-TG levels and the oestrogen content of the contraceptive pills in our-study. Both studies are at variance with the report from Ludlam et al.l who found no such elevation. The
mean
(SD) ng/ml
Like Aranda et al. we used the Amersham radioimmunoassay kit, but in our assay, instead of the sample tubes supplied by the manufacturer, we used tubes containing the mixture of
EDTA, theophylline, and prostaglandin EI.2 We have found that our normal values for &bgr;- TG, although similar to the original values of Ludlam et al.’ (19+0.75 ng/ml), are lower than those published by other groups2-4 who use the Amersham kit without modification. Reference to the different values of p-TG levels found by using these two different sample tubes has already been made in a Lancet editorial.5 In our assay, 95% of all values in our control group were less than 30 ng/ml. On the other hand, the normal values detected by Aranda’s group (41+20 ng/ml) are higher than most published values. 1-4 Total sample-to-assay time was 45 min in Aranda’s study, which is less than that recommended by Ludlam and Cash2 and by the kit manufacturer. If insufficient time were allowed for cooling on ice/water, 0-4°C (at least 30 min according to K. Kabareck of the Radiochemical Centre, Amersham) before 30 min centrifugation, this could account for the generally high values that Aranda et al. found.
conflicting results are similar to reports in the literaindicating both normal6 and abnormal4,7 levels of p-TG in similar groups of diabetic patients; perhaps the discrepant results of p-TG studies on diabetics and women on oral contraceptives can be explained by differences in sample acquisition and handling. These
ture
Department of Pathology, Mayo Clinic, Rochester, Minnesota 55901,
U.S.A.
ALEXANDER DUNCAN
CA, Moore S, Bolton AE, Pepper DS, Cash JD. Thromb Res 1975; 6: 543-48. 2. Ludlam CA, Cash JD. Br J Hœmatol 1976; 39: 239-47. 3 Broughton BJ, Allington MD, King A. Br J Hæmatol 1978; 40: 125-32. 4 Burrows AW, Chavin SI, Hockaday TDR. Lancet 1978; i: 235-37. 5. Lancet 1978; i: 250. 6. Campbell IN, Dawes J, Fraser DM, Pepper DS, Clark B, Cash JD. Diabetes 1. Ludlam
t’LU2 In-vivo acid-base bances.
diagram showing
location of chronic distur-
accompanying diagram is an updated version of one published three years ago. The intersection of PC02 and pH The
allows the metabolic disturbance to be read from the Y-axis in mmol/1. It is easier to comprehend mmol/1 of metabolic acidosis (or alkalosis) than to grapple with negative (or positive) base excess. This diagram positions chronic respiratory and metabolic conditions where intuition would place them-midway between total compensation and no compensation (i.e., either midway between pH 7-4 and pure respiratory disturbance [the zero line] or midway between pH 7-4 and pure metabolic disturbance [the PC02 S-33 line]). Clinical educational experience with this diagram suggests it to be a representation with some advantages, not the least of which is that it avoids base excess, standard bicarbonate, and actual bicarbonate. Department of Anesthesiology, Upstate Medical Center, Syracuse, New York 13210, U.S.A.
A. W. GROGONO
ARE THERE ANTIGENIC VARIANTS OF HEPATITIS A VIRUS?
SIR,-Hepatitis B virus has several serological subtypes of its surface antigen, but hepatitis A virus (HAV) is considered to be serologically uniform. Our findings make this view of HAV questionable. In experiments to standardise a solid-phase radioimmunoassay (SPIRA) for HAV and virus-specific antibodies immune serum gammaglobulin from the HAVAb kit of Abbott (IGUSA) and gammaglobulin prepared from a pool of convalescent sera (IG-USSR) were used. The sources of virus samples were faeces from hepatitis A patients in Moscow (F375-Moscow) ; Central Asia (F245-CA); West Germany (FD-FRG), kindly provided by Prof. F. Deinhardt and Dr G. Frosner; and Bulgaria (FBA-PRB), kindly supplied by Dr M. Teokharova. SPIRA tests revealed HA antigen in F375-Moscow and
1977; 26: 1175-77. 7. Preston FE, Ward JD, Marcola BH, Porter NR, BC. Lancet 1978; i: 238-41.
Timperley WR, O’Malley
1.
Grogono AW, Byles PH,
Hawke W. An in-vivo representation of acid-base balance. Lancet 1976; ii: 499.