Erythrocyte cation cotransport and countertransport in essential hypertension.

We studied erythrocyte cation cotransport and countertransport systems in 21 and 27 patients with essential hypertension, respectively, all of whom were under 50 years of age, had a diastolic blood pressure level greater than 100 mm Hg, and had a family history of hypertension. The following parameters were normal in nearly all patients: total erythrocyte Na+ and K+ concentrations, the maximal rate (Vmax) of inward cotransport, the affinity of cotransport with Rb+ as the substrate, the net outward cotransport of Na+ ions, the passive "leak" influx of Rb,+ and the maximal rate of Li+-Na+ countertransport. Only four patients gave clearly abnormal results; in two the maximal rate of both cotransport and countertransport was double the normal values, while another two patients demonstrated a greater than twofold increase in passive "leak" influx to Rb+ ions. Most of the patients with moderate to severe essential hypertension in this Australian study were characterized by normal erythrocyte cation fluxes, but a few showed elevation of both cotransport and countertransport of cations.

Proximal motor neuropathy, dermato-endocrine syndrome, and IgG kappa paraproteinemia.

The association of monoclonal paraproteinemia, neuropathy, and dermato-endocrine disturbances is well recognized in Japan, and it also occurs in white patients. Neuropathy in such patients is classically distal and sensorimotor, and the paraprotein almost always contains lambda light chains. A 58-year-old white man presented with severe progressive proximal motor neuropathy, dermato-endocrine changes, and an IgG kappa paraprotein. Over a 2 1/2-year period, treatment with melphalan and prednisolone produced improvement in the neuropathy and resolution of dermato-endocrine features with a corresponding decline in the serum paraprotein concentration. Subsequent reappearance of the paraprotein, despite treatment, was associated with clinical relapse.

Plasma-dependent and -independent mechanisms of platelet aggregation induced by human tumour cell lines.

Tumour cell induced platelet aggregation (TCIPA) may facilitate haematogenous tumour metastasis. In this study of the aggregatory responses of human platelets to human tumour cell lines, we have found two distinct mechanisms of TCIPA. Colon carcinoma lines Colo 205 and Colo 397 produced TCIPA which was dependent upon thrombin generated through the activation of clotting factor VII, consistent with the expression of tissue factor activity by these cells. This mechanism was calcium dependent and was partially mediated by platelet ADP release as it was inhibited by apyrase. A uterine carcinosarcoma line (Colo 526) produced TCIPA by a novel mechanism which was dependent upon calcium, but was independent of thrombin generation and of the presence of plasma proteins, indicating that this aggregatory response is initiated by a direct platelet-tumour cell interaction.

Protein-bound cobalamin absorption declines in the elderly.

A modified protein-bound cobalamin absorption test was used to study dietary cobalamin absorption in healthy adults of different age groups and patients with isolated low serum concentrations of cobalamin. Dietary cobalamin absorption was significantly reduced in healthy adults aged 55-75 years compared with young adults, with a further reduction in those older than 75 years. No difference was detected between dietary cobalamin absorption in patients with isolated low serum cobalamin and controls of a similar age group. Cobalamin malabsorption was associated with elevated serum gastrin. The diagnostic value of this protein-bound cobalamin absorption test in the elderly was limited by the frequent finding of reduced absorption in healthy elderly people with normal serum cobalamin concentrations. The performance of such tests should be evaluated in different age groups before application in diagnosis.

Acquired amegakaryocytic thrombocytopaenia in a child.

A boy aged 5 years is described with amegakaryocytic thrombocytopaenia, which was associated with defective granulopoiesis and erythropoiesis, but did not evolve into marrow aplasia. Marrow cultures confirmed the presence of abnormalities in each of the haemopoietic lineages and identified defective maturation of megakaryocytic precursors. The was no evidence of a humoral inhibitor of megakaryopoiesis. The patient's blood cell counts responded to treatment with oxymetholone.

Hyperviscosity syndrome secondary to rheumatoid arthritis.

A women with longstanding seropositive rheumatoid arthritis presented with the insidious onset of a hyperviscosity syndrome. This responded to plasma exchange and corticosteroids. Plasma exchange was complicated by severe bleeding which was associated with disturbances of coagulation and of platelet function related to the marked increase in plasma immunoglobulins.

High-dose chemotherapy with busulphan and cyclophosphamide and bone-marrow transplantation for drug-sensitive malignancies in adults: a preliminary report.

The technique of high-dose chemotherapy and bone-marrow transplantation takes advantage of any potential dose-response effect in the treatment of cancer and the ability of infused marrow to circumvent severe myelotoxicity. We report our initial experience of 20 high-dose chemotherapy procedures with busulphan and cyclophosphamide as the treatment regimen. Autologous (14 patients), human leukocyte antigen-matched, sibling-allogeneic (five patients) and identical-twin (one patient) transplantations were performed in patients with leukaemias (12 patients), lymphomas (seven patients) or a germ-cell tumour (one patient). One in-hospital and one late death occurred as a result of the toxicity of high-dose chemotherapy. All evaluable patients demonstrated bone-marrow engraftment and became independent of blood transfusions. Five of six patients who were treated in partial remission or relapse obtained a complete remission. Seven patients have relapsed. Eleven patients currently are alive and disease-free and nine patients have returned to their full-time occupations. High-dose chemotherapy can be undertaken with an over-all morbidity that is similar to that which is experienced during the induction chemotherapy of acute leukaemia.