763 breast. If so, one would anticipate the L/R ratios to be greater in younger women, since familial aggregation of this cancer tends to occur before menopause. However, the laterality effect was primarily seen around and after the menopause, when breast-cancer patterns appear to reflect environmental
factors.6 Environmental Epidemiology and Biometry Branches, National Cancer Institute,
WILLIAM J. BLOT
Bethesda, Maryland 20014, U.S.A.
JOHN L. YOUNG, JR
to
feed from the other breast while the infected breast
kept inactive by an absence of suckling. Some weeks later, when the breast had healed, the baby was allowed to suckle, and within a few days full lactation returned to this breast. was
lower the serum-cholesterol
to
normal in moderate
College, Cambridge Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ
J. MARKS
A. N. HOWARD
HYPERCAPNIA DURING OXYGEN THERAPY
SIR,-We were interested to read the hypothesis of Dr Rudolf and his colleagues (Sept. 3, p. 483) about the increase in carbon-dioxide retention during oxygen therapy in patients with acute-on-chronic respiratory failure. A similar hypothesis to explain high-altitude acclimatisationl.2 has been disproved by studies of cerebral glucose metabolism which demonstrated no difference in cerebral anaerobic metabolism between subjects resident at high altitude and at sea level. Similar studies of the patients of Rudolf et al. would be of value. Although we are ignorant of the metabolic effects of cerebral hypoxia and its consequences, we doubt whether cerebral hypoxia per se is a ventilatory stimulant since depression of ventilation after only a short period of isocapnic hypoxia has been described in
man.4
Department of Pædiatrics, Charing Cross Hospital,
HUGH
London W6 8RF
JOLLY
FETAL HICCUPS
SIR,-In confirming the observations of Dr Lewis and Mr Trudinger (Aug. 13, p. 355) on fetal hiccups we would draw attention to two possibly important features in the study of fetal movements as an index of fetal wellbeing.’ Using equipment similar to theirs (ADR 2130 Kretztechnik) we have noticed that in the presence of even slight degrees of polyhydromnios the patient is much less sensitive to apparently normal fetal movements although these are easily demonstrable by ultrasound. Further, in some normal pregnancies mothers, although aware of intra-abdominal disturbances, fail to interas fetal movements until they have seen them disthe real-time screen. Both these features could lead to error when the mother counts fetal movements and so lead to a false impression of the condition of the fetus.
pret them ’
can
Girton
JOSEPH F. FRAUMENI, JR
SIR,-Professor MacMahon and Professor Trichopoulos (Sept. 24, p. 656) consider that Tanka women must have a most unusual physiology if the unsuckled breast does not lactate. In the days when breast infection was not uncommon I would frequently suggest that a mother rest the infected breast by allowing suckling from the healthy breast only. I recollect one mother with a breast abscess requiring incision who continued
milk
hypercholesterolaemia.
played on
Department of Midwifery and Gynaecology, Queen’s University of Belfast,
In our study of arterial blood gases during sleep in patients with chronic ventilatory failure,’ we reported the -response to oxygen therapy during sleep in two patients in remission. Hypoxic drive was intact in patient 6 and absent in patient 9. The accompanying figure shows that the rise in arterial carbon-dioxide tension (P I1co during sleep when breathing oxygen was much greater in patient 6 than in patient 9. We explained this finding in terms of the current hypothesis but have now reconsidered it in the light of Rudolfs suggested modification. Neither the increased P aco2 of patient 6 nor the observed time-course conform to the new hypothesis. We consider that the marked increase in Pco2 seen during acute exacerbations is probably due to a further decrease in the 1. 2. 3. 4. 5.
Sørensen, S. C., Mines, A. H. J. appl. Physiol. 1970, 28, 832. Sørensen, S. C., Milledge, J. S. ibid 1971, 31, 28. Sørensen, S. C., Lassen, N. A., Severinghaus, J. W., Coudert, J., Zamora, M. P. ibid. 1974, 37, 305. Kronenberg, R., Hamilton, F. N., Gabel, R., Hickey, R., Read, D. J. C., Severinghaus, J. W. Respiration Physiol. 1972, 16, 109. Leitch, A. G., Clancy, L. J., Leggett, R. J. E., Tweeddale, P., Dawson, P., Evans, J. I. Thorax, 1976, 31, 730.
W. K. RITCHIE W. A. H. RITCHIE W. THOMPSON
J.
Institute of Clinical Science, Belfast BT12 6BJ
HYPOCHOLESTEROLÆMIC EFFECT OF MILK
SIR,-Dr Helms (Sept. 10, p. 556) suggests that the hypocholesterolaemic factor which we found in milk (July 30, p. 255) is lactose. We have now done two further experiments. Cottage cheese (mainly curds containing casein, calcium, a little cream but almost no lactose) achieved no serum-cholesterol reduction. Lactose (100 g/day, equivalent to four pints or about 2-1litres of milk) was followed by a significant (p
factors.6 Environmental Epidemiology and Biometry Branches, National Cancer Institute,
WILLIAM J. BLOT
Bethesda, Maryland 20014, U.S.A.
JOHN L. YOUNG, JR
to
feed from the other breast while the infected breast
kept inactive by an absence of suckling. Some weeks later, when the breast had healed, the baby was allowed to suckle, and within a few days full lactation returned to this breast. was
lower the serum-cholesterol
to
normal in moderate
College, Cambridge Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 2QQ
J. MARKS
A. N. HOWARD
HYPERCAPNIA DURING OXYGEN THERAPY
SIR,-We were interested to read the hypothesis of Dr Rudolf and his colleagues (Sept. 3, p. 483) about the increase in carbon-dioxide retention during oxygen therapy in patients with acute-on-chronic respiratory failure. A similar hypothesis to explain high-altitude acclimatisationl.2 has been disproved by studies of cerebral glucose metabolism which demonstrated no difference in cerebral anaerobic metabolism between subjects resident at high altitude and at sea level. Similar studies of the patients of Rudolf et al. would be of value. Although we are ignorant of the metabolic effects of cerebral hypoxia and its consequences, we doubt whether cerebral hypoxia per se is a ventilatory stimulant since depression of ventilation after only a short period of isocapnic hypoxia has been described in
man.4
Department of Pædiatrics, Charing Cross Hospital,
HUGH
London W6 8RF
JOLLY
FETAL HICCUPS
SIR,-In confirming the observations of Dr Lewis and Mr Trudinger (Aug. 13, p. 355) on fetal hiccups we would draw attention to two possibly important features in the study of fetal movements as an index of fetal wellbeing.’ Using equipment similar to theirs (ADR 2130 Kretztechnik) we have noticed that in the presence of even slight degrees of polyhydromnios the patient is much less sensitive to apparently normal fetal movements although these are easily demonstrable by ultrasound. Further, in some normal pregnancies mothers, although aware of intra-abdominal disturbances, fail to interas fetal movements until they have seen them disthe real-time screen. Both these features could lead to error when the mother counts fetal movements and so lead to a false impression of the condition of the fetus.
pret them ’
can
Girton
JOSEPH F. FRAUMENI, JR
SIR,-Professor MacMahon and Professor Trichopoulos (Sept. 24, p. 656) consider that Tanka women must have a most unusual physiology if the unsuckled breast does not lactate. In the days when breast infection was not uncommon I would frequently suggest that a mother rest the infected breast by allowing suckling from the healthy breast only. I recollect one mother with a breast abscess requiring incision who continued
milk
hypercholesterolaemia.
played on
Department of Midwifery and Gynaecology, Queen’s University of Belfast,
In our study of arterial blood gases during sleep in patients with chronic ventilatory failure,’ we reported the -response to oxygen therapy during sleep in two patients in remission. Hypoxic drive was intact in patient 6 and absent in patient 9. The accompanying figure shows that the rise in arterial carbon-dioxide tension (P I1co during sleep when breathing oxygen was much greater in patient 6 than in patient 9. We explained this finding in terms of the current hypothesis but have now reconsidered it in the light of Rudolfs suggested modification. Neither the increased P aco2 of patient 6 nor the observed time-course conform to the new hypothesis. We consider that the marked increase in Pco2 seen during acute exacerbations is probably due to a further decrease in the 1. 2. 3. 4. 5.
Sørensen, S. C., Mines, A. H. J. appl. Physiol. 1970, 28, 832. Sørensen, S. C., Milledge, J. S. ibid 1971, 31, 28. Sørensen, S. C., Lassen, N. A., Severinghaus, J. W., Coudert, J., Zamora, M. P. ibid. 1974, 37, 305. Kronenberg, R., Hamilton, F. N., Gabel, R., Hickey, R., Read, D. J. C., Severinghaus, J. W. Respiration Physiol. 1972, 16, 109. Leitch, A. G., Clancy, L. J., Leggett, R. J. E., Tweeddale, P., Dawson, P., Evans, J. I. Thorax, 1976, 31, 730.
W. K. RITCHIE W. A. H. RITCHIE W. THOMPSON
J.
Institute of Clinical Science, Belfast BT12 6BJ
HYPOCHOLESTEROLÆMIC EFFECT OF MILK
SIR,-Dr Helms (Sept. 10, p. 556) suggests that the hypocholesterolaemic factor which we found in milk (July 30, p. 255) is lactose. We have now done two further experiments. Cottage cheese (mainly curds containing casein, calcium, a little cream but almost no lactose) achieved no serum-cholesterol reduction. Lactose (100 g/day, equivalent to four pints or about 2-1litres of milk) was followed by a significant (p
