long cours de I’hydroxyuree. J . Dermatol. Venereol. 111, 895-900 VOMVOUKAS S . , PAKULA A.S. & SHAW J.M. (1991) Multiple pigmented nail bands during Hydroxyurea therapy. An uncommon finding. J . Am. Acad. Derma&ol.24. 1016-I017
P.R. Kelsey Department of Haematology, Victoria Hospital, Blackpool FY3 8 N R
available and transfusion is contraindicated (EDLIZ 1989).
References Essential Drugs List for Zimbabwe (EDLIZ): Guidelines for the treatment of medical conditions common in Zimbabwe (1989). Ministry of Health, Harare p. 80 MUKIIEI J.M., PAULB. & MANDISODZA A. (1989) Megaloblastic anaemia in Zimbabwe: seasonal variation. Cent. Afr. J . Med. 35, 310-313 PAULB. (1981) Rain and anaemia-seasonal variation of malaria and megaloblastosis. J . Med. Assoc. of Malawi 8, 19-20
Pernicious anaemia in Africans Sir: We were interested to read of the Nigerian experience of pernicious anaemia (PA) (Akinyanju 0.0.& Okany C.C. CIinJab. Haemat. 1992, 14, 33-40), and would agree with them that pernicious anaemia does occur in black Africans. Between September 1987 and November 1988 we investigated 30 adult black Zimbabweans (M20 : FIO) by Schilling tests (Dicopac, Amersham, but used in two stages) in whom a megalobalastic marrow was associated with vitamin B,, deficiency ( < 150 pg/l). The result was normal in 7 (23%) reflecting dietary deficiency, malabsortion in 8 (27%), and 11 (36%) had a ratio of isotope excretion > 2 : 1 consistent with pernicious anaemia (or other cause of failure of intrinsic factor secretion). In 4 patients a low result in the first part could not bc interpreted as the second stage was not carried out. From a small hospital based study it is difficult to give accurate incidence figures. Using the 1982 census data for age 50 years and over (only one patient with PA younger than 50), and assuming a catchment population of 5 million for the major Harare hospitals, gives an incidence of pernicious anaemia of 1 in 22000. The true incidence is likely to be higher as not all cases of megaloblastic anaemia would have been referred to us; it is still much less than in Caucasians. The major cause of megaloblastic anaemia continues to be folate deficiency in Zimbabwe (Mukiibi, Paul & Mandisodza 1989) and also as seen in Malawi this shows marked seasonal variation (Paul 1981). However, for safe medical practice we recommend that both B,, and folk acid are given until assay results are
Department of Haematology Victoria Hospital Worksop S80 2BN
(address for correspondence) A. Mandizodza Department of Medical Laboratory Technology University of Zimbabwe PO Box A178, Avondale Harare Zimbabwe
Use of flow cytochemistry in early diagnosis of acute myocardial infarction Sir: Diagnosis in early stages of acute myocardial infarction (AMI) is often difficult, as clinical features may not be typical and ECG changes or increased cardiac enzymes may not be detectable yet. On the other hand AM1 is usually followed by leucocytosis which is thought to be related to both necrotic and thrombotic (Marcus et al. 1985) process as well as to the stimulation of leucocyte production by the elevated glucocorticoids that occur with infarction; it is also thought that the role of activated neutrophils is probably to produce intermediates like B4 and oxygen-free radicals (Fantone et al. 1982; Engler et al. 1986) which exert important microcirculatory effects (Marcus et al. 1985). Given that the bone marrow needs some time to respond to the stress of an AMI, leucocytosis is not always apparent when a patient with acute and severe retrosternal chest pain presents to casualty, as this would depend on how long ago the onset of pain had been. The aim of this small study was to explore the possibility of detecting early changes in the white cells by using data from