- Email: [email protected]
EYES RIGHT
438 as others have. We consider this simple inexpensive test to be useful for the diagnosis of peritoneal effluent leukocytosis. Its use by CAPD patients at home as an early indicator of peritonitis ’
requires more study. We thank Boehringer Mannheim Canada for supplying the test strips, the Kidney Foundation of Canada for student fellowship support of D. W. W., and the nurses of the peritoneal dialysis unit for the sample collection.
Departments of Pediatrics and Hematology and Nephrology Program, St. Joseph’s Hospital and McMaster University,
Hamilton, Ontario, Canada
R. MORRISON HURLEY DEAN W. WRIGHT GERALD W. WILSON MAHMOUD A. M. ALI
ETHYLENE, AN OVULATORY HORMONE? SIR,-Ethylene, a gaseous plant hormone, is exhaled by man but its role in mammalian physiology remains uncertain. I have detected a significant increase of ethylene in the breath of females at the time of ovulation. Ethylene was measured in the breath of fifteen normal subjects who were non-smokers and had not received any medication. They included five males aged 26-42, five non-pregnant females aged 22-34, and five pregnant females aged 22-26. Each subject exhaled 100 litres of air into a neoprene bag on awakening after an overnight fast of approximately lOh. Sublingual temperature was recorded before the collection. Studies were done once a week on pregnant women before delivery and daily thereafter for a week. They were done daily on other subjects for 3 months. The extraction procedure I was similar to that of Ram Chandra and Spencer. Normal females exhaled fairly consistent amounts of ethylene daily (table) and in all of them the output increased significantly (t = 5 - 09, p<0 00 1) at about the time of ovulation. This increase followed a midcycle rise in basal body temperature and always exceeded the mean volume plus three standard deviations. It recurred in each women for three consecutive cycles, and on every occasion ethylene output returned to basal levels within 24 h. Two women experienced midcycle pain (Mittelschmerz); their maximum ethylene oxide excretion occurred within 12 h of this event and menstruation was recorded 14 days later. Pregnant females and males did not show this pattern. Consistent amounts of ethylene were excreted throughout the study and occasional surges never exceeded the mean basal volume plus two standard deviations. There was no significant difference in the basal outputs of each group (table). Several women not included in this study received oral contraceptives and had an excretory pattern similar to that in males; presumably, ovulation had been suppressed. Ripening fruits excrete large amounts of ethylene and, in botanical terms, the gas participates in the maturation of ovarian components. It is conceivable that the human ovum may require ethylene for the ripening process at the time of ovulation. The surge in output of ethylene could not be accurately timed but it coincided with the midcycle rise in basal body temperature. Luteinising hormone shows a significant rise in production at this stage and together with follicle stimulating hormone (FSH) is important in the ripening of the ovum. Ethylene may participate in human physiology rather than be produced solely as a byproduct of metabolism. Department of Paediatrics and Child Health, University of Cape Town, Medical School, Observatory 7925, South Africa
V. C. HARRISON
1. Ram Chandra G, Spencer M. A micro-apparatus for absorption ofethylene and its use in determination of ethylene in exhaled gases from human subjects. Biochim Biophys Acta 1963, 69: 423-25. ETHYLENE OUTPUT
(PARTS/ 106)
ORGANIC SOLVENTS AND T LYMPHOCYTES
SIR,-Current laboratory methods for evaluating the effects of
organic solvents on the health of industrial workers permit the diagnosis of occupational disease rather than the early results of ex. posure. Neoplasms of the lymphoreticular system are more frequent than expected in populations exposed to benzene.I Since, in antitumour immunity, T lymphocytes play a key role we decided to in vestigate the effect of solvents containing benzene and its homo. logues on T lymphocytes. In 106 healthy workers (47 women and 59 men) working fromtwoto 122 months in contact with solvents for paints and varnishes T lymphocytes were counted in the peripheral blood by the Ea test (early rosettes) and the EI8h test (late rosettes) using W.H.O. methods. Chemical and toxicological examinations of the air at the work places showed that in years 1968-78 benzene, toluene and xylene concentrations ranged from zero up to 370,580, and 506 met, respectively. Urinary concentrations of phenol and hippuric acid confirmed absorption of benzene and toluene.2 T LYMPHOCYTE COUNTS PERIPHERAL. BLOOD IN WORKERS OCCUPATIONAL ORGANIC SOLVENTS
The results indicate that T lymphocyte counts are diminished only-workers with long exposure to solvents. The coefficient of partial correlation between the T lymphocyte count and exposure time with regard to age was - 0 - 293 (p<0 - 01) for Ea rosettes and for E 18h rosettes r was - 0 -344 (p<0 - 0001). There was no correlation between the T cell count and age. Numbers of B and null lym-
phocytes were not altered. Provincial Immunological 32-800 Brzesko, Poland
Laboratory,
PAULIN MOSZCZYNSKI
EYES RIGHT
SIR,-I was surprised by the spelling of some latinized names of Legionella species in Dr Ackley’s letter (Jan. 24, p. 221). Surely in forming such names of modern people the quoted genitive singular case-endings are not correct when derived from a male person called Bozemann or Gorman. The correct spelling should be bozemannior gormani. Dumoffii would be right if the name of the man thus honoured is Dumoffi, but if Dumoff then dumoffi would be right (dumoffae if the new species is dedicated to a woman). These simple rules of Latin declension have been frequently violated in the past, particularly by medical entomologists whose records are cluttered up by mis-spelled Anopheles rossii (after Ross), A. austenii (after Austen) orA. bancroftii (after Bancroft). These jarring names cannot be easily amended if they were published before 1958, when the International Code of Zoological Nomenclature (1961) was adopted by the XVth International Congress of Zoology in London and came into force. One would hope that bacteriologists would follow these eminently rational and grammatical principles of scientific nomenclature. Wellcome Museum of Medical Science, Wellcome Building,
London NW1 2BP
1. Vianna
*The average
parts/106.
reading for figures exceeding mean±SD (see text)
was
0 48-0
L. J. BRUCE-CHWATT
NJ, Polan A. Lymphomas and occupational benzene exposure Lancet 1979, i: 1394-95. 2 Moszczynski P. Cytoenzymatic studies on neutrophils in workers having contact with organic solvents containing benzene, toluene and xylene. Folio Haematol 1980, 107: 747-56.
439
** Professor Bruce-Chwatt puts bacteria in zoos. However, for a long time now these organisms have been named in accordance with the International Code of Nomenclature of Bacterial and not the botanical or zoological codes. The rules for substantive epithets include: "For personal names ending with a consonant (other than 2 - er). Addition: -ii (masculine), -ae (feminine)." The approved list2 in more recent but the several contains specific epithets ending -ii,
Legionella species were proposed after this publication."-ED.L. GREEN-LIPPED MUSSEL EXTRACT IN ARTHRITIS
SIR,-With reference to your Jan. to our recent
10
editorial, in which you refer
paper,3 we have the following comments.
The fact that oral administration of ’Seatone’ is ineffective in rat experiments does not mean that oral administration in man will also be ineffective; carrageenan-induced arthritis in rats and rheumatoid arthritis and osteoarthritis in man are completely different. Out pilot study included controls since all the patients who took part in the trial had been under treatment with non-steroidal antiinflammatory drugs for periods ranging from several months to several years, without clinical improvement. They therefore served as their own controls, and their progress before and after treatment with the mussel extract was compared. This is one of the best clinical controls, and certainly the one most often used in practice. We agree that dividing the active group into responders and nonresponders may make interpretation of the results difficult. If responders and non-responders are used, the following results are obtained (table). There was a net improvement of 3707o in the rheumatoid group and of 36% in the osteoarthritic group. The two placebo groups were then put on to active treatment for a further three months. There was a net improvement of 60% in the rheumatoid group and of 29% in the osteoarthritic group. Comparison of the articular index, limbering-up time, and functional index between the treated and placebo rheumatoid patients showed improvements in the treated group which were NUMBER OF PATIENTS IMPROVED ON ACTIVE AND PLACEBO TREATMENTS IN THE RHEUMATOID ARTHRITIS AND OSTEOARTHRITIS GROUPS
significant at the 95%, 90%, and 95% confidence limits, respectively. Comparison of the pain scored by means of the visual analogue method, functional index, and the time taken to walk 50 ft, between the treated and placebo osteoarthritic patients, showed improvements in the treated group which were significant at the 95%, 99%, and 95% confidence levels respectively. The fact that green-lipped mussel has no obvious effect on haematology and blood chemistry is scarcely surprising. No firstline anti-inflammatory therapies have any consistent effect on these indices. In this respect, seatone is no different from any other antiarthritic drugs in common use. We agree that analysis has not yielded any substances other than those compatible with marine existence. This is not surprising since Perna canaliculus is a marine animal. However, the comment that no component so far found in seatone could account for any antiinflammatory activity is largely irrelevant. There are components of seatone which have not yet been isolated or identified, and even if we could identify all of the numerous Lapage SP,
and others, eds. International code of nomenclature of bacteria: 1976 Washington, DC: American Society for Microbiology, for the International Association of Microbiological Societies, 1975. 2 Approved list of bacterial names. Int J Syst Bact 1980; 30: 225. 3. Gibson RG, Gibson SLM, Conway V, Chappell D. Perna canaliculus in the treatment of arthritis. Practitioner 1980; 224: 955-60. 1
revision
seatone and determine their effects singly on arthritic patients we would have no way of knowing how they act in combination, a question that our studies answered clinically. To suggest that because seatone has few side effects, it must be clinically inert, is ridiculous. This is tantamount to saying that to get a desirable clinical effect, we must accept a certain number of undesirable and possibly dangerous side effects. In our experience of treating over 500 patients, green-lipped mussel extract has proved to be the single most effective preparation which we have yet encountered for the treatment of both rheumatoid arthritis and osteoarthritis. ROBIN G. GIBSON Glasgow Homoeopathic Hospital, SHEILA L. M. GIBSON Glasgow G12 0NR
components of
EFFECT OF CYCLOSPORIN A ON IMMUNOLOGICAL RECOVERY AFTER BONE MARROW TRANSPLANTATION
SiR.—Dr Jacobs and Dr Gordon-Smith (Dec. 13, p. 1296) stress the fact that little is known of the effect in vivo of cyclosporin A (CyA) and that its responsibility for the development of lymphoma is not proven. In vitro, Cy-A is a potent inhibitor of T-cell function, and the T-cell cytotoxic response to Epstein-Barr virus infected B-cells of patients receiving Cy-A after renal allograft is inhibited.22 However, studies of humoral and cellular immune response of patients on Cy-A therapy have not been published, and this information might be important to our understanding of the mechanism of the development of lymphomas. Eight patients receiving Cy-A at an initial dose of 20 mg/kg intramuscularly and 12-55 mg/kg by mouth subsequently, were followed up for 6 months after allogeneic bone marrow transplantation for acute leukaemia. All were transplanted in complete remission after high dose cyclophosphamide and total body irradiation. None had graft-versus-host disease (GVHD) beyond stage i. Responses to phytohaemagglutinin, concanavalin A, and allogeneic cells of blood lymphocytes returned to normal within 3-6 months in seven patients. IgG and IgM levels never fell below normal. In one of two patients with low IgA levels, the IgA value was already low before bone marrow transplantation. We do not yet have an adequate control group. However, the Seattle transplantation team has shown3that the above immunological indices took between 6 months and 2 years to return to normal in patients given bone marrow transplants for severe aplastic anaemia and end-stage leukaemia. Immunological recovery was most delayed in patients with GVHD. Although our patients were grafted in complete remission and escaped GVHD beyond stage i it does seem that Cy-A does not delay immunological reconstitution in such patients-indeed, as reported by Powles et a1.4-there is strong evidence that Cy-A can prevent GVHD. Thus the immunosuppressive effect of Cy-A must be very selective since major T-cell functions and immunoglobulin levels do not seem to be altered in patients receiving this drug. If Cy-A is directly responsible for the development oflymphoma, it is unlikely that general immunodepression is an important factor. Immunology and Transplantation Unit, Hôpital Cantonal Universitaire, 1211 Geneva 4, Switzerland; and Department of Haematology,
Kantonsspital, Basel 1.
VLADIMIR E. VON FLIEDNER ALOIS GRATHWOHL MICHEL JEANNET CATHERINE NISSEN BRUNO SPECK
Horsburgh T, Wood P, Brent L. Suppression of in vitro lymphocyte reactivity by cyclosporin A: Existence of a population of drug-resistant cytotoxic lymphocytes.
Nature 1980; 286: 609-11 D, Sweng P, Edwards J, Janossy G, Hoffbrand AV. Long-term T-cellmediated immunity to Epstein-Barr virus in renal-allograft recipients receiving cyclosporin-A. Lancet 1981; i: 10-12. 3. Noel DR, Witherspoon RP, Storb R, Atkinson K, Doney K, Mickelson EM, Ochs HD, Warren RP, Weiden PL, Thomas ED. Does graft-versus-host disease influence the tempo of immunologic recovery after allogenic human marrow transplantation? An observation on 56 long-term survivors. Blood 1978; 51: 1087-105. 4 Powles RL, Clink HM, Spence D, Morgenstern G, Watson JG, Selby PH, Woods M, Barrett A, Jameson B, Sloane J, Lawler SD, Kay HEM, Lawson D, McElwain TJ, Alexander P. Cyclosporin A to prevent graft-versus-host disease in man after allogenic bone-marrow transplantation. Lancet 1980; i: 327-29.
2. Crawford
requires more study. We thank Boehringer Mannheim Canada for supplying the test strips, the Kidney Foundation of Canada for student fellowship support of D. W. W., and the nurses of the peritoneal dialysis unit for the sample collection.
Departments of Pediatrics and Hematology and Nephrology Program, St. Joseph’s Hospital and McMaster University,
Hamilton, Ontario, Canada
R. MORRISON HURLEY DEAN W. WRIGHT GERALD W. WILSON MAHMOUD A. M. ALI
ETHYLENE, AN OVULATORY HORMONE? SIR,-Ethylene, a gaseous plant hormone, is exhaled by man but its role in mammalian physiology remains uncertain. I have detected a significant increase of ethylene in the breath of females at the time of ovulation. Ethylene was measured in the breath of fifteen normal subjects who were non-smokers and had not received any medication. They included five males aged 26-42, five non-pregnant females aged 22-34, and five pregnant females aged 22-26. Each subject exhaled 100 litres of air into a neoprene bag on awakening after an overnight fast of approximately lOh. Sublingual temperature was recorded before the collection. Studies were done once a week on pregnant women before delivery and daily thereafter for a week. They were done daily on other subjects for 3 months. The extraction procedure I was similar to that of Ram Chandra and Spencer. Normal females exhaled fairly consistent amounts of ethylene daily (table) and in all of them the output increased significantly (t = 5 - 09, p<0 00 1) at about the time of ovulation. This increase followed a midcycle rise in basal body temperature and always exceeded the mean volume plus three standard deviations. It recurred in each women for three consecutive cycles, and on every occasion ethylene output returned to basal levels within 24 h. Two women experienced midcycle pain (Mittelschmerz); their maximum ethylene oxide excretion occurred within 12 h of this event and menstruation was recorded 14 days later. Pregnant females and males did not show this pattern. Consistent amounts of ethylene were excreted throughout the study and occasional surges never exceeded the mean basal volume plus two standard deviations. There was no significant difference in the basal outputs of each group (table). Several women not included in this study received oral contraceptives and had an excretory pattern similar to that in males; presumably, ovulation had been suppressed. Ripening fruits excrete large amounts of ethylene and, in botanical terms, the gas participates in the maturation of ovarian components. It is conceivable that the human ovum may require ethylene for the ripening process at the time of ovulation. The surge in output of ethylene could not be accurately timed but it coincided with the midcycle rise in basal body temperature. Luteinising hormone shows a significant rise in production at this stage and together with follicle stimulating hormone (FSH) is important in the ripening of the ovum. Ethylene may participate in human physiology rather than be produced solely as a byproduct of metabolism. Department of Paediatrics and Child Health, University of Cape Town, Medical School, Observatory 7925, South Africa
V. C. HARRISON
1. Ram Chandra G, Spencer M. A micro-apparatus for absorption ofethylene and its use in determination of ethylene in exhaled gases from human subjects. Biochim Biophys Acta 1963, 69: 423-25. ETHYLENE OUTPUT
(PARTS/ 106)
ORGANIC SOLVENTS AND T LYMPHOCYTES
SIR,-Current laboratory methods for evaluating the effects of
organic solvents on the health of industrial workers permit the diagnosis of occupational disease rather than the early results of ex. posure. Neoplasms of the lymphoreticular system are more frequent than expected in populations exposed to benzene.I Since, in antitumour immunity, T lymphocytes play a key role we decided to in vestigate the effect of solvents containing benzene and its homo. logues on T lymphocytes. In 106 healthy workers (47 women and 59 men) working fromtwoto 122 months in contact with solvents for paints and varnishes T lymphocytes were counted in the peripheral blood by the Ea test (early rosettes) and the EI8h test (late rosettes) using W.H.O. methods. Chemical and toxicological examinations of the air at the work places showed that in years 1968-78 benzene, toluene and xylene concentrations ranged from zero up to 370,580, and 506 met, respectively. Urinary concentrations of phenol and hippuric acid confirmed absorption of benzene and toluene.2 T LYMPHOCYTE COUNTS PERIPHERAL. BLOOD IN WORKERS OCCUPATIONAL ORGANIC SOLVENTS
The results indicate that T lymphocyte counts are diminished only-workers with long exposure to solvents. The coefficient of partial correlation between the T lymphocyte count and exposure time with regard to age was - 0 - 293 (p<0 - 01) for Ea rosettes and for E 18h rosettes r was - 0 -344 (p<0 - 0001). There was no correlation between the T cell count and age. Numbers of B and null lym-
phocytes were not altered. Provincial Immunological 32-800 Brzesko, Poland
Laboratory,
PAULIN MOSZCZYNSKI
EYES RIGHT
SIR,-I was surprised by the spelling of some latinized names of Legionella species in Dr Ackley’s letter (Jan. 24, p. 221). Surely in forming such names of modern people the quoted genitive singular case-endings are not correct when derived from a male person called Bozemann or Gorman. The correct spelling should be bozemannior gormani. Dumoffii would be right if the name of the man thus honoured is Dumoffi, but if Dumoff then dumoffi would be right (dumoffae if the new species is dedicated to a woman). These simple rules of Latin declension have been frequently violated in the past, particularly by medical entomologists whose records are cluttered up by mis-spelled Anopheles rossii (after Ross), A. austenii (after Austen) orA. bancroftii (after Bancroft). These jarring names cannot be easily amended if they were published before 1958, when the International Code of Zoological Nomenclature (1961) was adopted by the XVth International Congress of Zoology in London and came into force. One would hope that bacteriologists would follow these eminently rational and grammatical principles of scientific nomenclature. Wellcome Museum of Medical Science, Wellcome Building,
London NW1 2BP
1. Vianna
*The average
parts/106.
reading for figures exceeding mean±SD (see text)
was
0 48-0
L. J. BRUCE-CHWATT
NJ, Polan A. Lymphomas and occupational benzene exposure Lancet 1979, i: 1394-95. 2 Moszczynski P. Cytoenzymatic studies on neutrophils in workers having contact with organic solvents containing benzene, toluene and xylene. Folio Haematol 1980, 107: 747-56.
439
** Professor Bruce-Chwatt puts bacteria in zoos. However, for a long time now these organisms have been named in accordance with the International Code of Nomenclature of Bacterial and not the botanical or zoological codes. The rules for substantive epithets include: "For personal names ending with a consonant (other than 2 - er). Addition: -ii (masculine), -ae (feminine)." The approved list2 in more recent but the several contains specific epithets ending -ii,
Legionella species were proposed after this publication."-ED.L. GREEN-LIPPED MUSSEL EXTRACT IN ARTHRITIS
SIR,-With reference to your Jan. to our recent
10
editorial, in which you refer
paper,3 we have the following comments.
The fact that oral administration of ’Seatone’ is ineffective in rat experiments does not mean that oral administration in man will also be ineffective; carrageenan-induced arthritis in rats and rheumatoid arthritis and osteoarthritis in man are completely different. Out pilot study included controls since all the patients who took part in the trial had been under treatment with non-steroidal antiinflammatory drugs for periods ranging from several months to several years, without clinical improvement. They therefore served as their own controls, and their progress before and after treatment with the mussel extract was compared. This is one of the best clinical controls, and certainly the one most often used in practice. We agree that dividing the active group into responders and nonresponders may make interpretation of the results difficult. If responders and non-responders are used, the following results are obtained (table). There was a net improvement of 3707o in the rheumatoid group and of 36% in the osteoarthritic group. The two placebo groups were then put on to active treatment for a further three months. There was a net improvement of 60% in the rheumatoid group and of 29% in the osteoarthritic group. Comparison of the articular index, limbering-up time, and functional index between the treated and placebo rheumatoid patients showed improvements in the treated group which were NUMBER OF PATIENTS IMPROVED ON ACTIVE AND PLACEBO TREATMENTS IN THE RHEUMATOID ARTHRITIS AND OSTEOARTHRITIS GROUPS
significant at the 95%, 90%, and 95% confidence limits, respectively. Comparison of the pain scored by means of the visual analogue method, functional index, and the time taken to walk 50 ft, between the treated and placebo osteoarthritic patients, showed improvements in the treated group which were significant at the 95%, 99%, and 95% confidence levels respectively. The fact that green-lipped mussel has no obvious effect on haematology and blood chemistry is scarcely surprising. No firstline anti-inflammatory therapies have any consistent effect on these indices. In this respect, seatone is no different from any other antiarthritic drugs in common use. We agree that analysis has not yielded any substances other than those compatible with marine existence. This is not surprising since Perna canaliculus is a marine animal. However, the comment that no component so far found in seatone could account for any antiinflammatory activity is largely irrelevant. There are components of seatone which have not yet been isolated or identified, and even if we could identify all of the numerous Lapage SP,
and others, eds. International code of nomenclature of bacteria: 1976 Washington, DC: American Society for Microbiology, for the International Association of Microbiological Societies, 1975. 2 Approved list of bacterial names. Int J Syst Bact 1980; 30: 225. 3. Gibson RG, Gibson SLM, Conway V, Chappell D. Perna canaliculus in the treatment of arthritis. Practitioner 1980; 224: 955-60. 1
revision
seatone and determine their effects singly on arthritic patients we would have no way of knowing how they act in combination, a question that our studies answered clinically. To suggest that because seatone has few side effects, it must be clinically inert, is ridiculous. This is tantamount to saying that to get a desirable clinical effect, we must accept a certain number of undesirable and possibly dangerous side effects. In our experience of treating over 500 patients, green-lipped mussel extract has proved to be the single most effective preparation which we have yet encountered for the treatment of both rheumatoid arthritis and osteoarthritis. ROBIN G. GIBSON Glasgow Homoeopathic Hospital, SHEILA L. M. GIBSON Glasgow G12 0NR
components of
EFFECT OF CYCLOSPORIN A ON IMMUNOLOGICAL RECOVERY AFTER BONE MARROW TRANSPLANTATION
SiR.—Dr Jacobs and Dr Gordon-Smith (Dec. 13, p. 1296) stress the fact that little is known of the effect in vivo of cyclosporin A (CyA) and that its responsibility for the development of lymphoma is not proven. In vitro, Cy-A is a potent inhibitor of T-cell function, and the T-cell cytotoxic response to Epstein-Barr virus infected B-cells of patients receiving Cy-A after renal allograft is inhibited.22 However, studies of humoral and cellular immune response of patients on Cy-A therapy have not been published, and this information might be important to our understanding of the mechanism of the development of lymphomas. Eight patients receiving Cy-A at an initial dose of 20 mg/kg intramuscularly and 12-55 mg/kg by mouth subsequently, were followed up for 6 months after allogeneic bone marrow transplantation for acute leukaemia. All were transplanted in complete remission after high dose cyclophosphamide and total body irradiation. None had graft-versus-host disease (GVHD) beyond stage i. Responses to phytohaemagglutinin, concanavalin A, and allogeneic cells of blood lymphocytes returned to normal within 3-6 months in seven patients. IgG and IgM levels never fell below normal. In one of two patients with low IgA levels, the IgA value was already low before bone marrow transplantation. We do not yet have an adequate control group. However, the Seattle transplantation team has shown3that the above immunological indices took between 6 months and 2 years to return to normal in patients given bone marrow transplants for severe aplastic anaemia and end-stage leukaemia. Immunological recovery was most delayed in patients with GVHD. Although our patients were grafted in complete remission and escaped GVHD beyond stage i it does seem that Cy-A does not delay immunological reconstitution in such patients-indeed, as reported by Powles et a1.4-there is strong evidence that Cy-A can prevent GVHD. Thus the immunosuppressive effect of Cy-A must be very selective since major T-cell functions and immunoglobulin levels do not seem to be altered in patients receiving this drug. If Cy-A is directly responsible for the development oflymphoma, it is unlikely that general immunodepression is an important factor. Immunology and Transplantation Unit, Hôpital Cantonal Universitaire, 1211 Geneva 4, Switzerland; and Department of Haematology,
Kantonsspital, Basel 1.
VLADIMIR E. VON FLIEDNER ALOIS GRATHWOHL MICHEL JEANNET CATHERINE NISSEN BRUNO SPECK
Horsburgh T, Wood P, Brent L. Suppression of in vitro lymphocyte reactivity by cyclosporin A: Existence of a population of drug-resistant cytotoxic lymphocytes.
Nature 1980; 286: 609-11 D, Sweng P, Edwards J, Janossy G, Hoffbrand AV. Long-term T-cellmediated immunity to Epstein-Barr virus in renal-allograft recipients receiving cyclosporin-A. Lancet 1981; i: 10-12. 3. Noel DR, Witherspoon RP, Storb R, Atkinson K, Doney K, Mickelson EM, Ochs HD, Warren RP, Weiden PL, Thomas ED. Does graft-versus-host disease influence the tempo of immunologic recovery after allogenic human marrow transplantation? An observation on 56 long-term survivors. Blood 1978; 51: 1087-105. 4 Powles RL, Clink HM, Spence D, Morgenstern G, Watson JG, Selby PH, Woods M, Barrett A, Jameson B, Sloane J, Lawler SD, Kay HEM, Lawson D, McElwain TJ, Alexander P. Cyclosporin A to prevent graft-versus-host disease in man after allogenic bone-marrow transplantation. Lancet 1980; i: 327-29.
2. Crawford