Die Mieloproliferatiewe Sindroom, Mielofibrose en Eritrositose

In a retrospective survey over 27 months the records of 76700 patients (39300 White, 37400 Black) admitted to the Bloemfontein Teaching Hospitals, were analysed in order to assess the incidence and nature of the myeloproliferative syndromes, myelofibrosis and erythrocytosis. Erythraemia (polycythaemia vera) was much less common among Black (1,7%) than among White (9,0%) patients, when expressed as a percentage of total patients with raised- haemoglobin and haematocrit. Myelofibrosis as part of the classical myeloproliferative syndrome was rare among the Black patients (1 out of 5 with histologically proven bone marrow fibrosis), and more common among Whites (3 out of 4 with marrow fibrosis). Chronic myeloid leukaemia showed no difference in racial incidence. Erythrocytosis (secondary polycythaemia) was common in both races (57 Blacks, 92 Whites), and causative analysis showed no significant sexual or racial differences, although the study was hampered by inadequate clinical data. Cyanotic heart and lung disease was responsible for 61,7% of cases. An association with tumours (9,3%) and hypertension and/or obliterative vascular disease (21,4%) was evident

Transient Thrombasthenia in a Patient with Tuberculosis

A 20-year-old Black female presented with menorrhagia and epistaxis. Similar episodes, two years previously, had necessitated blood transfusion. No association with drug ingestion was found and the family history revealed no bleeding diathesis. The patient had a normal platelet count and a prolonged bleeding time. Platelet aggregation, clot retraction and platelet factor 3 release were grossly abnormal. She had axillary tuberculous lymphadenitis and chemotherapy was initiated. Three months later there was no clinical or laboratory evidence of a platelet abnormality. No reason for this transient thrombasthenia, which is unknown to us, was found. Glanzmann's disease is a hereditary thrombasthenia with a similar qualitative platelet defect

The effect of sepsis and short-term exposure to nitrous oxide on the bone marrow and the metabolism of vitamin B 12 and folate

It is recognised that prolonged anaesthesia with nitrous oxide (N20) induces megaloblastic anaemia by oxidising vitamin B12 To determine whether sepsis aggravates the effect of H20 on haemopoiesis 5 patients with severe sepsis, who required surgery and were exposed to short-term (45 - 105 minutes) N20 anaesthesia, were studied. Hone had evidence of pre-operative vitamin B12 or folate deficiency. The effect of the combination of N20 anaesthesia and sepsis on DNA synthesis in bone marrow cells was assessed morphologically, and by the deoxyuridine suppression test. In 3 patients exposed to the longest duration (75 - 105 minutes) of N20, addition of folinic acid and vitamin B12 partially improved the utilisation of deoxyuridine in vitro. No patient had evidence of megaloblastic haemopoiesis as judged by bone marrow morphology. It is concluded that prolonged N20 anaesthesia in patients with severe sepsis may adversely affect DNA synthesis. Although this effect did not manifest as overt megaloblastic erythropoiesis, it may be prudent to avoid N20 in such patients

Book Reviews

Book 1Book Title: Getting into Residency: A Guide for Medical StudentsBook Author: Kenneth V. IsersonPp. xviii + 431. $28,95. Tucson: Galen Press. 1993. ISBN 1-883620-10-4.Book 2Book Title: Molecular Biology of Digestive DiseaseBook Author: Ed. by Philip QuirkePp. vii + 116. £15. London: BMJ. 1994. ISBN 0-7279-0827-8.Book 3Book Title: Parkinson's DiseaseBook Author:  Ed. by Merton Sandler.Pp. ix + 65. £12/US$24. London: John Libbey, 1993. ISBN 0-86196-404-7.Book 4Book Title: Brain Work and Mental Activity: Quantitative Studies With Radioactive TracersBook Author: Ed. by N. A. Lassen, D. A. Ingvar, M. A. Raichle & L. FribergPP. 446. Illustrated. Copenhagen: Munksgaard. 1991. ISBN 87-16-10698-9.Book 5Book Title: Guidelines for Quality Assurance Programmes for Blood Transfusion ServicesBook Author: WHOPp. IV + 50. (Available in English; French and Spanish in preparation). SFr.12/US$10,80 (in developing countries SFr.8,40). Geneva: WHO. 1993. ISBN 92-4-154448-1. Order No. 1150392.Book 6Book Title: ABC of AlcoholBook Author: Ed. by Alex PatonPp. ix + 32. illustrated. £10. London: BMJ. 1994. ISBN 0-7279-D812-X.Book 7Book Title: Atlas of Surgical Exposures ofthe Lower ExtremityBook Author: A. Masquelet, C. McCullough, R Tubiana, I. Fyfe, L. Klenerman, E. LetoumelPp. 414. Illustrated. London: Manin Dunitz. 1993. ISBN 1-85317-D03-8

Adhesion of

111Indium-labelled autologus blood platelets administered to patients preoperatively can be traced in the components of the extracorporeal circuit by gamma camera scintillation imaging. Quantitative assessments can be made of platelet/biomaterial adhesion. It was thus possible to compare the ratio of adherent platelets on the defoaming systems of two types of Bentley BOS-10 oxygenators. The results indicated that more platelets adhered to the areas of the defoamer where gas bubbles burst than to areas such as the gaseous micro-emboli inhibitor sponge through which all the bubbles had to pass in the later types of BOS-10 oxygenator. In both types the pattern of platelet adhesion to the defoamer layers was comparable and was not influenced by bypass time. Gamma camera images of the oxygenators showed that most platelet adhesion took place in areas of blood/gas to biomaterial interfaces. Tubing circuits and cannulae displayed negligible 111 Indium activity on their surfaces, while the oxygenators held a mean of 8.5% of the activity administered to the patients. This technique could be applied to study platelet interaction with various extracorporeal circuits and oxygenators and may help to clarify the role of cardiopulmonary bypass (CPB) in thrombocytopoenia during heart surgery cases