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Biomedical subjects

R G Gray

Publications and source records attributed to R G Gray.

At least 55 records · Page 3Linked to original sources
PubMed1989

The significance of ultrastructural features in acute myeloid leukemia: a study of 220 patients entered into the Medical Research Council's ninth acute myeloid leukemia trial.

Samples of peripheral blood or bone marrow obtained before treatment from 220 patients entered into the Medical Research Council's ninth acute myeloid leukemia (AML) trial were examined by electron microscopy. Several ultrastructural features showed strong correlations with each other, with variants of AML defined by the Hayhoe classification scheme, and with FAB type. However, no ultrastructural feature was found either uniquely in association with any other or specifically in any variant of AML. Each ultrastructural feature was tested for association with achievement of remission, remission duration, and survival time. Only Auer rods were associated with a high remission rate (p = 0.01), but even this association was not quite conventionally significant when the analysis was not quite conventionally significant when the analysis was stratified for age (p = 0.055). Shorter duration of remission was associated with cytoplasmic projections (p = 0.04 stratified for age). Overall survival was worse when convoluted or lobed nuclei were present but only when stratified for age and Hayhoe type (p = 0.04). The possibility of testing combinations of ultrastructural features for correlation with diagnosis or prognosis is discussed but would require data from more than the present 220 patients to be meaningful.

Bone Marrow↗
PubMed1988

Terminal deoxynucleotidyl transferase and HLA-DR expression appear unrelated to prognosis of acute myeloid leukaemia.

Mononuclear cells from peripheral blood or bone marrow from 314 patients with acute myeloid leukaemia were examined for the presence of nuclear terminal deoxynucleotidyl transferase (304 patients), surface membrane expression of HLA-DR (314 patients) and the common acute lymphoblastic leukaemia antigen (281 patients). All patients were treated with identical remission induction chemotherapy, and morphological diagnosis was carried out in a central laboratory. The overall complete remission rate was 70%. There were no significant correlations between the immunological markers and complete remission rate, duration of remission, or survival.

Adolescent↗
PubMed1987

Increased excretion of propan-1,3-diol and 3-hydroxypropionic acid apparently caused by abnormal bacterial metabolism in the gut.

Three patients who died in infancy showed an unusual urinary organic acid pattern with excessive excretion of 3-hydroxypropionic acid but none of the other metabolites normally associated with propionyl-CoA carboxylase deficiency. Propan-1,3-diol was present in the urine in all three cases. In the two patients examined propionyl-CoA carboxylase activity was not deficient in cultured skin fibroblasts. A fourth patient, also severely ill, showed similar urinary abnormalities. Feeding a medium-chain triglyceride-rich diet to this patient increased the ratio of 3-hydroxypropionic acid to propan-1,3-diol and resulted also in the appearance of malonic acid in the urine. These abnormal metabolites disappeared on the administration of neomycin and presumably were produced by gut bacteria.

Aging↗
PubMed1987

Prenatal diagnosis of medium-chain acyl-coenzyme A dehydrogenase deficiency.

A fatal case of medium-chain acyl-coenzyme A dehydrogenase deficiency is described in a patient who presented with hypoglycaemia and a gross non-ketotic dicarboxylic aciduria. Cultured skin fibroblasts released 14CO2 from [1-14C] octanoic acid at half the normal rate. Prenatal diagnosis was undertaken in a subsequent pregnancy in which cultured amniotic fluid cells revealed a marked reduction in octanoate oxidation indicative of an affected fetus. The pregnancy was terminated and the diagnosis was confirmed by enzyme analysis of skin fibroblasts taken from the fetus. The high residual octanoate oxidation by affected fibroblasts together with the absence of any characteristic abnormality of amniotic fluid organic acids are a potential limitation to the reliability of this type of prenatal diagnosis.

Acyl-CoA Dehydrogenase↗
PubMed1987

Methylmalonic semialdehyde dehydrogenase deficiency: demonstration of defective valine and beta-alanine metabolism and reduced malonic semialdehyde dehydrogenase activity in cultured fibroblasts.

Intact cultured fibroblasts from a child with a new metabolic disorder, thought to be due to a deficiency of methylmalonic semialdehyde dehydrogenase, produced labeled CO2 normally from [1-14C]valine but not from [2-14C]valine. CO2 production from labeled beta-alanine was also much reduced, confirming the suspicion that malonic semialdehyde dehydrogenase is also deficient in this condition. An assay for malonic semialdehyde dehydrogenase in cell homogenates showed low activity but it was impossible to assess the degree of reduction.

Alanine↗
PubMed1987

A myelodysplastic syndrome with marrow eosinophilia terminating in acute nonlymphocytic leukemia, associated with an abnormal chromosome 16.

A patient presented with a myelodysplastic syndrome and bone marrow eosinophilia that evolved six months later into an acute nonlymphocytic leukemia (ANLL). Cytogenetic analyses of the bone marrow revealed 86% of the metaphases with 45,X-Y,inv(16)(p13;q22),t(11;17) (q11;q25),del(21)(q13) and 14% of the metaphases with the same abnormalities but with a Y chromosome. The association of ANLL, bone marrow eosinophilia, and abnormal chromosome 16 has previously been reported and has been suggested to have a favorable prognosis. Our patient is unique in that ANLL was preceded by a preleukemic phase associated with bone marrow eosinophilia. When complete remission was achieved, the bone marrow cytogenetics returned to normal, and the eosinophilia disappeared.

Bone Marrow↗
PubMed1986

Principal results of the Medical Research Council's 8th acute myeloid leukaemia trial.

Between 1978 and 1983, 1127 patients with de-novo acute myeloid leukaemia (AML) were entered into the Medical Research Council (MRC)'s 8th AML trial. All received the same induction therapy consisting of daunorubicin, cytarabine, and 6-thioguanine--DAT (1 + 5). The 67% who entered complete remission were randomised to consolidation with two or six further courses of DAT. Adults under the age of 55 were randomised for central nervous system (CNS) prophylaxis with intrathecal cytarabine and methotrexate. Finally, those still in remission after 1 year of cytarabine and 6-thioguanine (AT) maintenance were randomised to receive either late intensification with cyclophosphamide, vincristine, cytarabine, and prednisolone (COAP) or continued AT. The median survival for the whole group was 12 months; the median duration of first remission was 15 months, with relapse-free survival at 5 years estimated at 18%. The factors most strongly associated with poor survival were performance status and age at presentation, but even among those over 60 years of age, half went into remission. Six courses of DAT consolidation gave a small advantage over two courses in reducing the number of late relapses but no significant survival advantage. Late intensification showed a marginally significant advantage over continued AT maintenance. The incidence of CNS relapse was low and unaffected by prophylaxis. The second remission rate varied from 10% when the first remission was shorter than 6 months to 61% when it had continued for more than 2 years. 40 patients received histocompatible allogeneic bone-marrow transplants in first remission. There was a high procedure-related death rate, particularly among patients over 30 years of age. Thus, initially at least, the transplanted group had shorter survival than a comparable group of chemotherapy-treated patients. Treatment specifications remained unchanged throughout the trial but those enrolled in the later half of the trial had a better (p = 0.003) survival.

Adolescent↗
PubMed1986

Percutaneous drainage of a tuberculous liver abscess.

The authors describe the management by percutaneous drainage of a rare solitary tuberculous liver abscess in a 37-year-old woman. Open surgical drainage of such abscesses can be avoided using percutaneous drainage combined with transcatheter infusions of antituberculous agents. For the safe and successful use of this method three criteria must be met: the abscess should be unilocular, there must be a safe access route and a previously sterile compartment must not be contaminated. In addition a small (22 or 23 gauge) needle should be used for the initial puncture.

Adult↗
PubMed1985

Riboflavin-responsive ethylmalonic-adipic aciduria.

A patient presenting with a condition resembling Reye's syndrome was found to have a urinary organic acid excretion pattern similar to those previously described in a single patient with ethylmalonic-adipic aciduria. The present patient responded clinically to riboflavin supplementation and his fibroblasts, when cultured in riboflavin-depleted medium, showed an abnormal reduction in the rate of butyrate oxidation.

Adipates↗