British journal of haematology
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The evolution of coagulation abnormalities was studied in Russell's viper bite victims who, on admission to hospital, showed no clinical signs of systemic envenoming. Based on the laboratory results and subsequent clinical course, three groups were distinguished. ⋯ The third group, consisting of nine patients, developed haemostatic abnormalities as early as 1-2 h after the bite, which progressed to severe defibrination 4-8 h later at which time antivenom was given. Comparison of the haemostatic abnormalities in the three groups suggested that serial monitoring of the serum FDP concentration may be of value in predicting the likelihood of systemic envenoming and progression to complete defibrination.
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Megaloblastic anaemia due to bacterial overgrowth of the small intestine is due to vitamin B12 malabsorption. This report describes a patient with bacterial overgrowth of the small intestine who had megaloblastic anaemia and malabsorption of vitamin B12, but persistently normal levels of serum vitamin B12 and normal serum and red cell folate levels. However, there was evidence of vitamin B12 deficiency as shown by an abnormal deoxyuridine suppression test and by the response to treatment with physiological doses of vitamin B12. A relative increase in biologically inactive vitamin B12 analogues may be the explanation for the normal vitamin B12 level in this patient.
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Thirty consecutive patients with leukaemia were prepared for bone marrow transplantation (BMT) with cyclophosphamide (CY) 120 mg/kg followed by total body irradiation (TBI). TBI was delivered in a single dose (sTBI) of 10 Gy, at a dose rate of 0.06-0.08 Gy/min, or in fractionated doses (fTBI) of 3.3 Gy/d, on each of 3 consecutive days, at the same dose rate. Lung shielding was adopted for all patients, in order to obtain a homogeneous dose delivered to the lung and at midline. ⋯ When compared to MTX, the use of CyA was associated with less GvHD and IP, but when only patients in remission given fTBI were analysed, this was no longer true. Relapses were mostly influenced by the remission status of the patient at transplant (P = 0.001). Although this is not a randomized study, our data suggest that fTBI can reduce the acute risks of marrow transplantation in leukaemia.
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Case Reports
Fibrinogen Chapel Hill II: defective in reactions with thrombin, factor XIIIa and plasmin.
Fibrinogen Chapel Hill II is a hereditary, abnormal fibrinogen which is characterized by poor substrate reactivity toward thrombin, factor XIIIa and plasmin. The patient has a low plasma level of clottable protein with normal antigen concentration, high amounts of fibrinogen related material in serum, and prolonged thrombin and reptilase clotting times. Fibrinopeptide release was decreased with both thrombin and ancrod, indicating that release of fibrinopeptide A from the abnormal fibrinogen was impaired. ⋯ Under conditions which yielded complete plasmin digestion of normal fibrinogen only half of the patient fibrinogen was degraded beyond the fragment X stage. The rate of fibrinopeptide release from patient fragment X and NH2-terminal disulphide knot (N-DSK) was similar to that from the fibrinogen, indicating that the defect was contained within the N-DSK. A simple amino acid substitution could result in a conformational defect in the N-DSK sufficient to perturb the reactions involving thrombin, factor XIIIa and plasmin and also polymerization.
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The effects of intensive plasma exchange on the circulating levels of coagulation factors I, II, V, VII, VIII, IX, X and antithrombin III were determined. During courses of daily exchange marked cumulative reductions of coagulation factors may occur, particularly in the case of factors I, II and X, although usually remaining above the levels considered adequate for haemostasis. ⋯ While antithrombin III levels were reduced during plasma exchange the results suggest that this may be partly due to consumption as well as physical removal. The very low incidence of haemorrhagic sequelae and absence of thrombotic events following plasma exchange at this Centre is explained by the maintenance of adequate levels of coagulation factors and of antithrombin III even during courses of daily plasma exchange.