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Biomedical subjects

R Ireland

Publications and source records attributed to R Ireland.

At least 37 records · Page 2Linked to original sources

GM-CSF augments the immunosuppressive capacity of neonatal spleen cells in vitro.

Addition of exogenous granulocyte-macrophage colony stimulating factor (GM-CSF) to cultures of adult murine spleen cells with sheep red blood cells (SRBC) results in an augmented plaque forming cell (PFC) response. The influence of GM-CSF on the ability of neonatal spleen cells to suppress the anti-SRBC plaque forming response of adult spleen cells was tested by adding GM-CSF to cultures of neonatal and adult spleen cells. The suppressive capacity of the neonatal spleen cells was augmented by exogenous GM-CSF. The augmented suppression of the neonatal spleen cells was dependent on a G-10 adherent population since the addition of GM-CSF to cultures containing G-10 passed neonatal spleen cells resulted in an augmented PFC response and not suppression. Neonatal splenic glass adherent cells were also capable of suppressing the response. Neonatal spleen cells or purified neonatal glass adherent spleen cells cultured in the presence of GM-CSF had markedly increased levels of PGE2 in the culture supernatant. Neonatal spleen cells cultured with GM-CSF had increased numbers of morphologically identifiable macrophages after 48 hr of culture. Both irradiation and G-10 passage of the neonatal spleen diminished the numbers of macrophages formed in response to GM-CSF, and both of these manipulations resulted in reversal of suppression in response to GM-CSF. Thus, the augmented suppressive capacity of neonatal spleen cells in response to GM-CSF is probably mediated by its ability to drive monocyte to macrophage differentiation as well as increase the suppressive capacity of the existing neonatal splenic macrophages by increasing their production of PGE2.

Animals↗

Anticardiolipin antibodies in patients from Malaysia with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is highly prevalent in Malaysia, which has a mixed population of Malays, Chinese, and Indians. A quantitative enzyme linked immunosorbent assay (ELISA) was used to determine anticardiolipin antibody (aCL) levels (total immunoglobulin, IgG, and IgM) in 200 patients with SLE (164 Chinese, 26 Malay, and 10 Indian) attending the University Hospital of Kuala Lumpur, Malaysia, and 103 matched controls. Only 33 (16.5%) of the patients had raised aCL levels; 26 had raised IgG aCL, five IgM aCL, and two both IgG and IgM aCL. There was a low prevalence of raised levels of aCL in the population studied, which was seen in conjunction with a rare occurrence of thrombosis. The classical association of high aCL levels with thrombocytopenia and recurrent abortions was noted, though not with cerebral disease. The low prevalence of aCL in this study population of mixed racial origin contrasts with findings in European patients with SLE and lends support to the influence of local factors, be they genetic or environmental, on the clinical manifestations of this disease.

Abortion, Habitual↗

T-cell interleukin 1 receptor cDNA expressed in Chinese hamster ovary cells regulates functional responses to interleukin 1.

We have cloned a cDNA encoding a receptor identical to the native Mr 80,000 glycoprotein that binds interleukin (IL) 1 alpha and -beta in murine T cells. Chinese hamster ovary (CHO) cells transfected with this T-cell IL-1 receptor (IL-1R) [CHO(IL-1R)] cDNA express approximately 100,000 IL-1Rs per cell, compared to the less than 100 receptors present on control CHO cells. For two functional responses to IL-1, prostaglandin synthesis and cytokine secretion, CHO(IL-1R) cells were 1000 times more sensitive to IL-1 alpha than were control CHO cells. Northern blot analysis and antibody precipitation demonstrated that one of the cytokines induced was granulocyte colony-stimulating factor and that mRNA levels for this cytokine were increased in CHO(IL-1R) cells by IL-1 alpha concentrations that had no effect on control cells. To establish the role of the recombinant receptors in signal transduction, an IL-1R cDNA modified by deletion of the predicted cytoplasmic domain was expressed in the CHO cell line termed CHO(IL-1R delta CT). CHO(IL-1R delta CT) cells expressed approximately 100,000 high-affinity IL-1 binding sites per cell, but these cells were less sensitive than control lines to IL-1, as measured by prostaglandin and cytokine release. These results show that the IL-1R cDNA encodes the entire functional receptor and that the cytoplasmic domain is required for signal transduction but not ligand binding.

Animals↗

Pre-ALL and non-A, non-B hepatitis infection.

We report a case of acute lymphoblastic leukaemia which presented as hypoplastic anaemia following Non-A, Non-B viral hepatitis infection. The role of infection and the mechanisms involved in the evolution of pre-ALL to overt leukaemia remain speculative. However, it is of practical importance to distinguish pre-ALL from aplastic anaemia and the myelodysplastic syndromes during the early pancytopenic phase to avoid inappropriate management.

Anemia, Aplastic↗

Pulmonary tuberculosis complicated by haemophagocytic syndrome and rifampicin-induced tubulointerstitial nephritis.

The benign, or infection-associated, haemophagocytic syndrome (IAHS) is a rare bone marrow disorder of macrophage cell proliferation diagnosed most commonly in immune compromised patients who develop herpes type viral infections (Risdall et al. 1979). It has also been reported in association with bacterial infections and rarely with mycobacterial infection (Chandra et al. 1975; Mamoharon & Catovsky 1981; Bultmann et al. 1982). Despite being potentially reversible it may produce a life-threatening pancytopenia (Seligman et al. 1972). We report a further case of the haemophagocytic syndrome associated with Mycobacterium tuberculosis in which thrombocytopenia was the predominant feature. There were unusual features in the clinical presentation and the patient's treatment and recovery were subsequently complicated by rifampicin-induced renal failure.

Bone Marrow↗

Adult T-cell lymphoma-leukaemia in Blacks from the West Indies.

Six Black patients (five born in the West Indies and one in Guyana), aged 21-55 years, had adult T-cell lymphoma-leukaemia diagnosed in the U.K. This disorder is rare in Europe and the U.S.A., but is more common in Japan. Five patients had severe hypercalcaemia which correlated with disease activity, although osteolytic lesions were found in only one. Other clinical features were lymphadenopathy and a high white blood-cell count (range 27-67 X 10(9)/l) with a predominance of pleomorphic lymphoid cells with pronounced nuclear irregularities prominent at ultrastructural level. The cells in all cases formed rosettes with sheep red blood-cells and lacked terminal transferase. Analysis with OKT monoclonal antibodies in four cases confirmed a mature T-cell phenotype defined as helper/inducer (T4+, T6-, T8-) in three. Combination chemotherapy resulted in short-lived remissions; four patients died and two have survived 3-6 months. The disease in these patients is indistinguishable on clinical and pathological grounds from adult T-cell leukaemia/lymphoma in Japan. Geographical clustering among certain racial groups suggests common aetiological factors in the pathogenesis of this disease. The finding of high titre antibody against the structural core protein (p24) of a new human C-type leukaemia virus (human T-cell leukaemia/lymphoma virus) in all tested cases from this series and data from all but one case from Japan suggest that one such factor may be viral.

Adult↗

Pattern of peptide synthesis in Drosophila cell lines and their hybrids.

Significant changes occurred in the rate of synthesis of several polypeptides in two different Drosophila cell lines following exposure to the steroid hormone, beta-ecdysone. For peptide 7/8, the synthetic rate increased by a factor of 10 in line S3 and by a factor of 1.3 in line MDR. In hormone-sensitive hybrids the rate increased by a factor of 3-4.5. For peptide 10 the synthetic rate decreased by a factor of 8 in line S3 but increased by a factor of 2 in line MDR. In hormone-sensitive hybrids the synthetic rate increased by a factor of 2-3. In hormone-insensitive cell lines no change in the rate of peptide synthesis occurred in the presence of hormone.

Animals↗

Evaluation of ultra-short dialysis.

A study was carried out to compare the effects of three dialysis regimens of different durations. Nineteen patients dialysed over 1975--7 for an average of only 11.2 hours per week were compared with nine dialysed for 24 hours per week (1974--6) and 10 dialysed for 27 hours (1971--3). Clinical, biochemical, and haematological results showed that the short dialysis regimen was as effective as the longer regimens, except that patients had to take a phosphate binder regularly, and that it was considerably cheaper. Short dialysis has social and economic benefits, since patients have more free time and more patients can be treated with the same number of staff and dialysis stations. As in many areas there is a shortage of places for patients needing dialysis, a short regimen is recommended.

Evaluation Studies as Topic↗

The use of hemoperfusion as an adjunct to hemodialysis.

Studies are reported on the use of short dialysis, sequential ultrafiltration/short dialysis and hemoperfusion in chronic renal failure. Short dialysis (less than 12 hours/week) is a satisfactory regime with good patient acceptance, adequate small and middle molecule clearance and control of fluid and blood pressure. Sequential ultrafiltration in the first hour improves fluid removal and reduces the side effects of dialysis. The addition of hemoperfusion increases clearance of small and middle molecules and has little effect on the osmolality of the serum. Thus, it does not increase the side effects of dialysis. Preliminary results suggest that hemoperfusion may be useful in the treatment of chronic renal failure in combination with ultrafiltration and dialysis.

Carbon↗