Biomedical subjects

P K MacCallum

Publications and source records attributed to P K MacCallum.

26 records · Page 2Linked to original sources

PubMed1993

Translocation t(6;9)(p23;q34) in acute myeloid leukemia without myelodysplasia or basophilia: two cases and a review of the literature.

The clinical, hematological, and cytogenetic data from two young adults with acute myeloid leukemia (AML) FAB type M1 is described. At diagnosis, cytogenetic investigation revealed the presence of the translocation t(6;9)(p23;q34). Bone marrow basophilia was not detected in either patient nor was there any evidence of preceding or underlying myelodysplasia. Both patients achieved complete remission (CR) and one patient remains in CR of over 5 years duration. It is suggested that the presence of basophilia may be associated with the myelodysplasia rather than the chromosome anomaly t(6;9).

Adult↗

PubMed1990

Effects of fixed minidose warfarin on coagulation and fibrinolysis following major gynaecological surgery.

Coagulation and fibrinolytic studies have been performed in patients who were undergoing major gynaecological surgery and randomised to either fixed minidose warfarin (1 mg daily) or matched placebo. With warfarin, a prolongation of the prothrombin time was observed on day 2 which persisted for at least 5 days and was greater than with placebo. The maximal postoperative mean INR was, however, only 1.2 which is considerably less than the target value for prophylaxis of deep vein thrombosis with full dose warfarin. The warfarin group showed two unexpected findings: significantly elevated fibrin specific degradation products throughout the postoperative period compared with placebo and absence of the expected rise of PAI, the major fibrinolytic inhibitor, on the first day after surgery. Levels of fibrinogen degradation products and F1 + 2 prothrombin fragments rose significantly and progressively in both groups in the postoperative period. With placebo, F1 + 2 showed an apparent higher percentage increase on each post-operative day but the differences between the groups were not significant. Increased fibrinolysis may be one of the mechanisms for the protective action of minidose warfarin in prophylaxis of DVT after major surgery.

Adult↗

PubMed1990

Reduction of factor VII coagulant activity (VIIC), a risk factor for ischaemic heart disease, by fixed dose warfarin: a double blind crossover study.

An increase in factor VII coagulant activity is known to be an important risk factor for ischaemic heart disease. Four hundred and eight healthy male Post Office workers were screened in an occupational survey. Sixty eight (16.5%) of these had values of factor VII coagulant activity greater than 1.0 SD above the age related mean. A randomised double-blind crossover study was undertaken to investigate the effect of a fixed daily minidose of warfarin (1 mg) on the high activities of factor VII in these men. Forty two agreed to enter the study and 40 completed it. Their mean factor VII coagulant activity before warfarin treatment was 135.9%. Treatment with a fixed minidose of warfarin significantly reduced factor VII coagulant activity to 124.6%; there was no change on placebo. The prothrombin time was also significantly prolonged on active treatment although all the results remained within the normal range. These findings suggested a fixed minidose warfarin regime might be useful in the primary prevention of ischaemic heart disease by reducing high activities of factor VII.

Adolescent↗

PubMed1988

A case of IgD myeloma presenting as diffuse osteosclerosis.

A case of IgD myeloma accompanied by diffuse osteosclerosis is reported. A trephine biopsy specimen showed only reticulin fibrosis, but histomorphometric analysis of a full thickness transiliac bone biopsy specimen showed increased trabecular bone mass, with no local deposit of tumour. An excess of bone surfaces were covered by osteoid seams, all of which showed active mineralisation, indicating a relative increase in osteoblastic activity; osteoclasis seemed to be unaffected. It is suggested that the cause of the generalised osteosclerosis might be production of an osteoblast stimulating factor by the myeloma cells.

Adult↗

PubMed1988

Extramedullary haemopoietic tumours complicating polycythaemia vera.

A 52 year old man with newly diagnosed polycythaemia vera in proliferative phase developed widespread extramedullary haemopoiesis (EMH), and died as a result of cervical cord compression. At necropsy, microscopic areas of primitive cells characteristic of granulocytic sarcoma were found within a large tumour of EMH in the right retroperitoneal region. Ultrastructural analysis showed unusual hexagonal inclusions within the cytoplasm of these primitive cells. Clinicians should be aware of the possibility of discrete haemopoietic tumours, whether EMH or granulocytic sarcoma, in patients with polycythaemia vera as well as in other myeloproliferative disorders.

Hematopoiesis, Extramedullary↗

PubMed1987

Massive right atrial thrombus associated with a Chiari network and a Hickman catheter.

The Chiari network is an embryologic remnant that is said to be present in only 1.5-3% of adults. It is rarely of clinical importance but may, very infrequently, be the site of thrombosis. The authors describe a patient in whom a massive right atrial thrombus formed on a Chiari network, leading to intermittent tricuspid obstruction. The thrombus had formed after the use of a Hickman catheter for the administration of cytotoxic chemotherapy. They can find no previously recorded examples of sufficient thrombus forming on a Chiari network to threaten life by obstructing the flow of blood through the heart.

Catheterization↗

PubMedDate not supplied

Etoposide in combination with intermediate dose cytosine arabinoside (ID ARA C) given with the intention of further myeloablative therapy for the treatment of refractory or recurrent hematological malignancy.

Thirty-four patients with refractory or recurrent high grade non-Hodgkin's lymphoma (NHL) or acute leukemia were treated with a combination of etoposide, 100 mg/m2 daily, and ara C, 1 g/m2 twice daily, for 5 days (VPARAC). This therapy was given in the anticipation that remissions thus achieved would be 'consolidated' with myeloablative therapy supported by bone marrow transplantation (BMT). The complete remission rate (CR) in patients with NHL was 3/18 (17 per cent) with partial responses (PR) seen in a further four patients, giving an overall response rate of 39 per cent. Four patients (three in CR, one in PR) proceeded to the planned consolidation treatment. Complete remission was achieved in 2/8 (25 per cent) patients with acute myelogenous leukemia (AML) and in 2/8 patients with acute lymphoblastic leukemia (ALL). Three of these patients subsequently had myeloablative consolidation therapy with BMT. There were four treatment-related deaths (NHL, two; AML, one; ALL, one). In poor risk patients with high grade NHL and acute leukemia, VPARAC is an effective remission induction programme in 21 per cent of patients. Seven of the original 34 patients received the intended 'curative' therapy, of whom only four are alive and well 1 year later.

Adolescent↗

PubMedDate not supplied

Polyradiculopathy complicating acute lymphoblastic leukemia.

A patient who presented with a symmetrical polyradiculopathy 6 months before the onset of acute lymphoblastic leukemia (ALL) is described. This case shows that bone marrow aspiration should be considered in such presentations when no other cause has been identified, even if the CSF is not initially diagnostic and the full blood count appears normal.

Adult↗