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Biomedical subjects

W Gregory

Publications and source records attributed to W Gregory.

53 records · Page 3Linked to original sources

Bone marrow transplantation for chronic myeloid leukaemia in first chronic phase: importance of a graft-versus-leukaemia effect.

We analysed the incidence of graft failure, graft-versus-host disease (GVHD) and relapse of leukaemia in 208 patients undergoing allogeneic bone marrow transplantation (BMT) for chronic myeloid leukaemia in chronic phase in eight transplant centres in Europe and the United States. 106 patients received unmanipulated donor bone marrow (Group 1) and 102 patients received marrow depleted of T-cells by incubation with the monoclonal antibodies Campath-1 or CT-2 and complement (Group 2). The incidence of graft failure was higher and of GVHD was lower in Group 2 than in Group 1. Relapse of leukaemia occurred more frequently in patients in Group 2 than in Group 1 (17 v. 2, P less than 0.001). Multivariate analysis showed that the following factors were associated with an increased risk of relapse: the use of T-cell depletion, the absence of GVHD and a high platelet count at the time of admission for transplant. The findings support the concept that a graft-versus-leukaemia effect mediated by T-lymphocytes is important for cure of leukaemia after BMT.

Adolescent↗

Failure to preserve fertility in patients with Hodgkin's disease.

The hypothesis that the "down-regulated" gonad is less vulnerable to the effects of cytotoxic chemotherapy for advanced Hodgkin's disease has been investigated. Thirty men and eighteen women were randomly allocated to receive an agonist analogue of gonadotrophin-releasing hormone prior to, and for the duration of, cytotoxic chemotherapy. Buserelin (d-Ser-[TBU]6 LHRH ethylamide) was prescribed in two different dosage schedules to twenty men, and in a single dosage schedule to eight women. A standard gonadotrophin-releasing hormone test (GnRH 100 micrograms) was performed 1 week prior to and on day 1 of each cycle of chemotherapy. In all patients peak luteinizing hormone responses to GnRH were suppressed throughout treatment. The higher of the two dosage schedules used in the men caused more effective suppression of luteinizing hormone, and both regimens led to an initial suppression of peak follicle-stimulating hormone responses to GnRH, which was not maintained. At follow-up assessment up to 3 years from the completion of treatment, all men treated with buserelin were profoundly oligospermic and four of the eight women were amenorrhoeic. All ten male controls were profoundly oligospermic, and six of nine female controls were amenorrhoeic. In the dosages and schedules investigated, buserelin was ineffective in conserving fertility.

Amenorrhea↗

A randomized trial comparing vindesine and cisplatinum to vindesine and methotrexate in advanced non small cell lung carcinoma.

Combination chemotherapy using vindesine and cisplatinum has been reported to be active in non-small cell lung carcinoma (NSCLC). In an attempt to reduce the potential neurotoxicity of this combination, and to assess the role of cisplatinum, a randomized trial has compared vindesine and cisplatinum to vindesine and methotrexate in 48 patients with advanced symptomatic NSCLC. Patient characteristics were similar in the two treatment arms. Objective tumour response and survival were similar for both treatments. No complete response occurred. Four patients receiving vindesine/cisplatinum (16%) and three patients receiving vindesine/methotrexate (13%) had a partial response. All responses occurred in patients with a performance status of 70% or more and no response was seen in patients with squamous cell carcinoma. Median survival for both regimens was 16 weeks. Toxicity was considerable and only six patients (12.5%) felt better on treatment. Nausea and vomiting were more frequent in the vindesine/cisplatinum arm, but mild neurotoxicity was more common in the vindesine/methotrexate arm. The low response rates, short survival and significant toxicity suggest that the role of combination chemotherapy in NSCLC remains to be established.

Antineoplastic Combined Chemotherapy Protocols↗

Maintenance chemotherapy for anaplastic small cell carcinoma of the bronchus: a randomised, controlled trial.

Since March 1980, 309 patients with anaplastic small cell carcinoma of the bronchus (ASCB) have received remission induction therapy prior to randomisation to maintenance (M) or no maintenance (NM) chemotherapy. Induction therapy consisted of six courses of vincristine, doxorubicin and cyclophosphamide (VAC) given IV every 3 weeks. Those with limited disease also received mediastinal irradiation. Consenting patients with no unequivocal residual disease were randomised to have no further treatment until relapse or a further eight courses of VAC, at a lower dosage, every 4 weeks. Patients failing to achieve randomisation status received palliative treatment only. The median survival for all patients with limited disease (LD) is 363 days and that for patients with extensive disease (ED) is 272 days (P less than 0.00001). Sixty-one patients with ED were randomised. Those having maintenance chemotherapy lived significantly longer (median 372 days) than those who did not continue therapy (median 259 days) (P = 0.006). An imbalance in the proportion of 'complete remitters' randomised to maintenance therapy does not account for this difference. There is no significant difference between the M and NM groups in the 32 randomised LD patients. Continuing treatment during remission with agents used to induce the remission can prolong survival in patients with extensive stage ASCB.

Antineoplastic Combined Chemotherapy Protocols↗

Monoclonal antibody assay of serum placental alkaline phosphatase in the monitoring of testicular tumours.

A monoclonal antibody (H17E2) recognising both placental alkaline phosphatase (PLAP) and testicular PLAP-like alkaline phosphatase was incorporated in a solid phase immunoassay. This was used to measure levels of PLAP in 257 sera from 148 patients with germ cell neoplasms of the testis. High levels of PLAP were found in all patients with active seminomas (mean 0.85 O.D.) compared to those in clinical remission (mean 0.20 O.D.) (P less than 0.0001). More importantly, changing levels of PLAP correlated with the course of disease in 79 samples from 33 patients with seminoma (P less than 0.0001). Elevated PLAP levels were also noted in patients in remission who were smokers (mean 0.32 O.D.) compared to non-smokers (mean 0.15 O.D.) (P less than 0.001). These data demonstrate that determination of PLAP levels using this sensitive immunoassay is an important new adjunct in the monitoring of the response to treatment in patients with seminoma.

Adult↗

Normal values for the different classes of venous blood mononuclear cells defined by monoclonal antibodies.

We present the data obtained from routine quantitation of normal venous blood mononuclear cells using 19 monoclonal antibodies against defined mononuclear cell surface antigens. The results indicate different values for percentage and absolute numbers of T lymphocytes and of T lymphocyte subsets depending on the monoclonal antibodies used to quantify these populations. In most instances the total number of identified cells was significantly less than the total number of recovered blood mononuclear cells, which suggests the existence in blood of a null cell population. Evidence is advanced to support previous observations that at least a proportion of this population is of B cell lineage, expressing cytoplasmic immunoglobulin but lacking other class or lineage specific markers. The value of a diverse monoclonal panel in routine quantitation of peripheral blood mononuclear cells is discussed.

Adult↗

Chemotherapy and immunotherapy for acute myelogenous leukemia.

Eighty-six consecutive untreated adults with acute myelogenous leukemia were treated with a combination of Adriamycin, vincristine, prednisolone, Cytosine Arabinoside, and BCG. Complete remission was achieved in 39 (45%) patients; these patients were then allocated on an alternate basis to receive BCG and monthly chemotherapy with or without weekly irradiated allogeneic blast cells. The median duration of remission was eight months and was the same for both groups. The median survival of those achieving complete remission was 19 months compared with two months for those not achieving complete remission. Nine patients are still alive without relapse and five of these patients have been disease free for more than three years.

Adolescent↗

Vertebrate lectins, Comparison of properties of beta-galactoside-binding lectins from tissues of calf and chicken.

Beta-galactoside-binding lectins were isolated from various calf tissues and from chicken hearts by affinity chromatography on asialofetuin-Sepharose, and were compared with respect to biochemical characteristics, binding properties, antigenic cross-reactivity, and cellular localization. The lectins are all thiol group-requiring, divalent cation-independent dimers, of apparent monomer mol wt 12,000 (calf lectins) or 13,000 (chicken lectin), and acidic pI. The calf lectins appear essentially identical by dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing, amino acid composition, and radioimmunoassay, while the chicken lectin is distinctly different by these criteria. However, all of the lectins competed for the same binding sites on rabbit erythrocytes, and could be inhibited by the same saccharide haptens (notably lactose and thiodigalactoside). Immuno-fluorescence studies on several cultured cell lines revealed that the bovine and chicken lectins had primarily an intracellular cytoplasmic localization. The beta-galactoside-binding lectins of vertebrates appear to be species-specific rather than tissue-specific.

Amino Acids↗

Metabolic polymorphisms.

Polymorphisms have been detected in a variety of xenobiotic-metabolizing enzymes at both the phenotypic and genotypic level. In the case of four enzymes, the cytochrome P450 CYP2D6, glutathione S-transferase mu, N-acetyltransferase 2 and serum cholinesterase, the majority of mutations which give rise to a defective phenotype have now been identified. Another group of enzymes show definite polymorphism at the phenotypic level but the exact genetic mechanisms responsible are not yet clear. These enzymes include the cytochromes P450 CYP1A1, CYP1A2 and a CYP2C form which metabolizes mephenytoin, a flavin-linked monooxygenase (fish-odour syndrome), paraoxonase, UDP-glucuronosyltransferase (Gilbert's syndrome) and thiopurine S-methyltransferase. In the case of a further group of enzymes, there is some evidence for polymorphism at either the phenotypic or genotypic level but this has not been unambiguously demonstrated. Examples of this class include the cytochrome P450 enzymes CYP2A6, CYP2E1, CYP2C9 and CYP3A4, xanthine oxidase, an S-oxidase which metabolizes carbocysteine, epoxide hydrolase, two forms of sulphotransferase and several methyltransferases. The nature of all these polymorphisms and possible polymorphisms is discussed in detail, with particular reference to the effects of this variation on drug metabolism and susceptibility to chemically-induced diseases.

Animals↗