British journal of haematology
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Glucose-6-phosphate dehydrogenase (G6PD) deficiency was detected in 16 (69.6%) of a group of 23 neonates who had unexplained moderate or severe jaundice. This proportion is significantly more than the 9.4% observed or the 22.2% expected in Jamaican neonates who are not moderately or severely jaundiced (P less than 0.003), and significantly more than the 12.6% observed or the 21.0% expected in older Jamaican children and adults (P less than 0.003). Phenobarbitone therapy and phototherapy reduced the need for exchange transfusion but this was necessary in eight patients. ⋯ These findings indicate that apparently spontaneous neonatal jaundice is important in infants who have the G6PD A--enzyme. However, the jaundice is probably precipitated by unknown factors to which the G6PD deficient neonate is more susceptible than the infant who is not G6PD deficient. THere is also a slightly increased incidence of G6PD deficiency in neonates who develop jaundice because of ABO or Rh(D) iso-immune disease, infection or prematurity.
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Five patients with immunopathologic renal disease, 12 with malignant paraproteinaemia and one with myasthenia gravis underwent a total of 179 plasma exchanges on a continuous flow cell separator. Replacement fluids devoid of coagulation factors were used in 160 exchanges while 19 exchanges were replaced with Fresh Frozen Plasma. Coagulation screening was done immediately before and 30 min after each plasma exchange. ⋯ Coagulation screening, including prothrombin ratio, thrombin time, reptilase time and partial thromboplastin time with kaolin showed progressively greater abnormalities as the intervals between exchanges shortened. The low incidence of clinical haemorrhagic episodes, three of 179 exchanges (2.2%), despite markedly abnormal coagulation parameters, emphasize the safety of the procedure even in moribund patients. We conclude that the use of FFP in intensive exchange programmes solely for the prevention of spontaneous haemorrhagic phenoma is unjustified.
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The results of cytological and ultrastructural analysis of erythroid burst colonies derived from the peripheral blood of two patients with HEMPAS have been compared to those obtained in normal controls. Using the plasma clot technique, in studies on 10 subjects we confirmed that most of the colonies consisted or erythroblasts with a synchronous and normal maturation involving a wave of nuclear extrusion at day 13. In contrast, the majority of well-haemoglobinized colonies from HEMPAS consisted of numerous bi- or multinucleated erythroblasts displaying the supplementary double membrane beneath their plasma membrane. ⋯ These cells were unable to mature and subsequently lysed. Thus dyserythropoiesis occurred in culture both at early and late stages of maturation. These studies clearly demonstrate that HEMPAS is a disorder resulting from defective erythroid committed cells.
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Randomized Controlled Trial Clinical Trial
Lack of effect of prednisone administration on bleeding time and platelet function of normal subjects.
The effect of 80 mg prednisone given orally for 2 d on normal and post-aspirin bleeding times and platelet function has been studied in a randomized, multiple cross-over, double-blind controlled trial in 12 normal volunteers. Mean template bleeding times were 6.6 min (placebo/placebo), 5.9 min (prednisone/placebo), 10.0 min (placebo/aspirin) and 8.7 min (prednisone/aspirin). ⋯ Prednisone had no effect on platelet glass bead retention nor on platelet aggregation by collagen, adrenalin and adenosine diphosphate. Thus conventional clinical doses of prednisone did not impair platelet function and did not enhance primary haemostatis in normal subjects as measured by the bleeding time.