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Biomedical subjects

A D Ho

Publications and source records attributed to A D Ho.

At least 181 records · Page 10Linked to original sources
PubMed1989

Disease-free survival after autologous bone marrow transplantation in patients with acute myelogenous leukemia.

Autologous bone marrow transplantation (ABMT) makes it possible to escalate the dose of cytotoxic treatment to a lethal range. Disease-free survival (DFS) following myeloablative therapy and ABMT has been shown to be superior to conventional treatment in high risk patients with acute myelogenous leukemia (AML). It was the purpose of the present study to compare hematopoietic reconstitution, actuarial DFS, and relapse rate of patients transplanted in first complete remission (CR) of AML with those in second or subsequent CR, and to evaluate transplant related mortality. Fifty-two patients with AML, 22 in first CR (low risk) and 30 in second or subsequent CR (high risk), underwent total body irradiation (12.1 to 16.7 Gy) and cyclophosphamide (CY) treatment (200 mg/kg) followed by ABMT. The autograft was incubated with the active CY derivative Mafosfamide (ASTA Werke, Bielefeld, Federal Republic of Germany) to reduce the number of possibly contaminating clonogenic tumor cells. All patients showed three lineage engraftments with platelet recovery observed as being the slowest. The transplant related death rate was low at 5.8%. There was no significant difference in the kinetics of polymorphonuclear (PMN) cell or platelet reconstitution between the low and high risk patient subgroups. The estimated probability of DFS (relapse) after ABMT in first CR was 61% (36%) compared with 34% (65%) in second or subsequent CR, the longest follow-up being 55 months and 57 months, respectively (median follow-up 31 months and 19 months, respectively). ABMT offers a stable long-term DFS when performed in first CR with no relapses occurring in over a year after transplantation. Six later relapses, however, were seen after ABMT in second or subsequent CR, although DFS was not statistically different from that of first remission patients (P = .72).

Adult↗
PubMed1989

Mitoxantrone and high-dose cytarabine as salvage therapy for refractory non-Hodgkin's lymphoma.

Mitoxantrone (Novantrone, NO) and high-dose cytarabine (Ara-C, AC) have each been shown in monotherapy trials to be active in non-Hodgkin's lymphoma (NHL). In the current study, a combination of the two drugs (NOAC) was administered to 31 patients with advanced NHL refractory to modern sequential chemotherapy regimens. Ara-C was administered at 3 g/m2 as a 3 hour infusion every 12 hours on day 1 (2 doses) and mitoxantrone at 10 mg/m2/day on days 2 and 3. Of the 18 patients with high-grade malignant NHL, six have attained a complete remission (CR) and two, a partial remission (PR). One CR and 5 PRs were achieved among the other 13 patients with intermediate or low-grade NHL. The median time to relapse (TTR) of patients achieving CR was 7 months with a range from 4 to 17 months. Myelosuppression with subsequent infections was the major toxicity of this regimen. The median duration of severe neutropenia (less than 0.5/nl) was 9 days with a range of 0 to 27 days and the median duration of severe thrombocytopenia (less than 20/nl), 5 days with a range of 0 to 35 days. Infectious complications during cytopenia was seen in 45.3% of the courses administered and fever of unidentified origin was seen in 42.3%. About 63% of the patients were hospitalized for intravenous antibiotic or antimycotic treatment. Other side effects were mild and included nausea, stomatitis, and transient tachycardia of greater than 100/min. Thus, this regimen was active in refractory NHL with poor prognosis, and the toxic side effects were not excessive. Evaluation of the activity of this regimen at higher dose levels of Ara-C is warranted.

Adolescent↗
PubMed1989

Primary glucocorticoid receptor defect with likely familial involvement.

A 29-year-old woman with moderately elevated blood pressure and signs of hyperandrogenism (hirsutism and acne) but without typical Cushing's syndrome symptoms has been followed for almost 6 years. Steroid and glucocorticoid receptor studies indicated a primary glucocorticoid receptor defect. Elevated androgen values were of special interest. Clinical manifestation of hyperandrogenism seemed not to be proportional to the biochemical findings. Therefore, the possibility of a partial androgen receptor defect should also be considered.

Acne Vulgaris↗
PubMed1989

Evidence for an osteoblast-activating factor in a patient with peripheral T-cell lymphoma and osteosclerosis.

A patient with peripheral T-cell Lymphoma and acquired, systemic osteosclerosis is described. Bone histology showed a spectacular activation of osteoblasts accompanyed by massive new bone formation. Alkaline phosphatase in serum was elevated and increased to greater than 2000 U/l when the lymphoma became refractory to chemotherapy. In the patient's serum an osteoblast-activating factor could be demonstrated using a rat osteogenic osteosarcoma cell line (ROS 17/2.8). The factor was absent during remission of the tumor. We conclude that osteosclerosis was a paraneoplastic syndrome in this patient due to the secretion of an osteoblast-stimulating factor by the T-cell lymphoma. This situation is similar to the secretion of osteoclast-activating factors described in B-cell lymphomas, particularly multiple myeloma. The characterization of such a factor could be of therapeutic relevance.

Adult↗
PubMed1989

Therapy of the myeloid blast phase of chronic granulocytic leukemia with plicamycin and hydroxyurea.

Treatment of the myeloid blast phase of chronic granulocytic leukemia is still a major problem in clinical hematology. Alternate-day plicamycin and hydroxyurea treatment was reported to induce remissions in the majority of patients with myeloid blast phase by Koller and Miller in 1986 Subsequently we treated eight patients according to this regimen. Complete remissions could not be achieved and no prolongation of median survival was observed. In two patients treatment had to be discontinued due to severe toxicity.

Adult↗
PubMed1989

Detection of P-glycoprotein in human leukemias using monoclonal antibodies.

Overexpression of a Mr 170,000 membrane glycoprotein (P-glycoprotein) is consistently associated with multidrug resistance in cell lines. Two monoclonal antibodies (Mab) against P-glycoprotein (265/F4 and C 219) were used to examine tumour samples from patients with leukemias for evidence of P-glycoprotein overexpression. High levels of P-glycoprotein (greater than 5% positive cells) were detected with both antibodies in samples from 3 out of 18 patients suggesting that a multidrug resistant phenotype may also occur in human leukemias.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

Phase-I trial of intravenous continuous infusion of tumor necrosis factor in advanced metastatic carcinomas.

Fifteen patients with advanced metastatic adenocarcinomas were treated in a phase-I study with continuous intravenous 24 h infusion of recombinant tumor necrosis factor alpha (TNF-alpha) in order to determine the maximum tolerated dose (MTD) and associated side-effects. Patients received 40-400 micrograms/m2 TNF-alpha once (arm A) or twice (arm B) weekly for a scheduled treatment period of 2 months. The observed systemic side-effects resembled those reported for interferons and included fever, chills, fatigue, headaches, myalgias, thrombocytopenia, prostration, and malaise. Dose-limiting toxicities, resulting in a median MTD of 200 micrograms/m2 for 24 h, were fever, chills, fatigue, myalgias, and thrombocytopenia. Out of 15 patients, 11 showed tumor progression, and 3 sustained in no change for over 2 months of treatment. A minor response was seen in 1 patient with a colorectal carcinoma and liver metastases. To reduce side-effects, patients were treated either with paracetamol or indomethacin. Higher MTDs were observed in patients treated with indomethacin. No detectable plasma TNF-alpha levels or TNF antibodies were measured under therapy (plasma TNF-alpha less than 20 pg/ml). We conclude that TNF-alpha appears to have some antineoplastic activity in patients with adenocarcinomas since 4 patients remained in no change or showed a minor response.

Antibodies↗
PubMed1989

Enzyme activities of leukemic cells and biochemical changes induced by deoxycoformycin in vitro--lack of correlation with clinical response.

Deoxycoformycin (DCF) is a specific inhibitor of adenosine deaminase (ADA) and has been shown to be active in lymphoid neoplasms. Cytotoxicity is thought to be mediated by the accumulation of deoxyadenosine (AdR) and deoxyadenosine triphosphate (dATP) which inhibits ribonucleotide reductase and DNA synthesis in rapidly proliferating cells. Others suggested mechanisms leading to cell death particularly in non-dividing cells include depletion of ATP and NAD pools, inhibition of S-adenosylhomocysteine (SAH) hydrolase and induction of DNA strand breaks. In patients with high leukemic counts who were subsequently treated with DCF, we have studied (a) the levels of ADA, ecto-5'-nucleotidase (5NT), deoxyadenosine kinase (AdR-kinase) and SAH-hydrolase in the leukemic cells; [b) the in-vitro effects of DCF on dATP, ATP, NAD, SAH-hydrolase levels and on DNA strand breaks; and (c) the correlation between these parameters with clinical response to DCF. No significant difference in ADA, 5NT, AdR-kinase and SAH-hydrolase activities could be found between responders and non-responders. Incubation of the leukemic cells in vitro with DCF caused an inhibition of ADA, an accumulation of dATP, a moderate reduction in ATP and NAD levels, a suppression of SAH-hydrolase activity and an increase in DNA strand breaks in practically all the leukemic samples, irrespective of clinical response. Our results show that neither measurement of these enzymes nor studies of these biochemical sequelae of ADA inhibition in vitro predicts clinical responsiveness to DCF therapy.

Adenosine Deaminase Inhibitors↗
PubMed1989

Immunohistological assessment of bone marrow biopsies from patients with hairy cell leukemia: changes following treatment with alpha-2-interferon and deoxycoformycin.

Forty-six bone marrow biopsies from twelve hairy cell leukemia (HCL) patients, treated with either interferon(IFN)-alpha-2 (n = 8) or 2'deoxycoformycin(DCF) (n = 4), were examined using cryostat sections and an immunoperoxidase technique. Using this sensitive method we were able to demonstrate residual hairy cell (HC) infiltration in five cases, in which evaluation with conventional staining techniques on plastic embedded biopsies revealed complete remission. The amount of HCs in these five samples ranged from 1 to 7% (mean: 3%) of bone marrow cells. Consecutive biopsies in individual HCL patients revealed no changes of the immunological phenotype (CD19, CD22, CD25, CD10, CD11c, FMC7, HLA-DR, surface immunoglobulins) during IFN and DCF treatment. Within the infiltrated bone marrow a considerable number of "reactive" T lymphocytes was identified with prevalence of the T-helper (CD4+) subtype in untreated cases, whereas T-suppressor/cytotoxic (CD8+) cells were within the normal range. IFN treatment resulted in a reduction of CD4+ T lymphocytes (p less than 0.02). Minor alterations of CD8+ T lymphocytes and NK cells (HNK-1 + lymphoid cells) were found in bone marrow during IFN treatment. In DCF-treated patients bone marrow T lymphocytes were markedly reduced below the values of normal bone marrow. This DCF-induced T-cell depression might be related to the clinical observation of persistent cellular immune dysfunctions in HCL patients despite a DCF-induced remission.

Adult↗
PubMed1989

Detection of the multidrug resistant phenotype in human tumours by monoclonal antibodies and the streptavidin-biotinylated phycoerythrin complex method.

The aim of this study was to find out whether the membrane glycoprotein P-170 can be detected in human tumours with both acquired and intrinsic resistance to chemotherapeutic agents using monoclonal antibodies (265/F4 and C219) and the streptavidin-biotinylated phycoerythrin complex method. Pretreated leukaemia cells and untreated lung and ovarian carcinomas were analysed. Two plasmacytomas and one leukaemia expressed high levels of P-glycoprotein, whereas two leukaemias showed moderate, and three leukaemias no expression of this protein. The intrinsic resistance was analysed with a panel of four human epidermoid lung cancer xenografts grown in nude mice. The expression of P-glycoprotein could be correlated with the degree of resistance. In addition, one out of five ovarian carcinomas revealed a high level of P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

Tumour necrosis factor production and natural killer cell activity in peripheral blood during treatment with recombinant tumour necrosis factor.

Tumour necrosis factor (TNF) has been found to be an important immunomodulator. Among other functions TNF activates natural killer (NK) cells and stimulates monocytes/macrophages in an autocrine fashion. TNF production and NK activity in peripheral blood mononuclear cells were determined in a clinical phase I study in which recombinant human (rh) TNF was administered as a continuous infusion weekly for a period of 8 weeks. Even though TNF production and NK activity were significantly reduced directly after rhTNF infusion the effect proved to be transient and most pronounced at the first rhTNF administration. One day after completion of the rhTNF infusion the peripheral cells released more TNF into the supernatant compared to TNF activity immediately before the rhTNF infusion. This effect was conspicuous in non-stimulated cultures. After repeated rhTNF infusions both stimulated and non-stimulated TNF production of the peripheral blood mononuclear cells was increased. NK cell activity was also enhanced after repeated cycles of rhTNF administration as compared to early rhTNF treatment. Thus, repeated rhTNF infusions lead to a stimulatory effect on TNF production and NK activity of peripheral blood cells.

Adult↗
PubMed1989

[NMR tomographic imaging of bone marrow infiltrates in malignant lymphoma].

10 normals and 37 patients with Hodgkins' and non-Hodgkin's lymphoma were examined by MRT as part of a prospective study (lumbar spine, pelvis, proximal femora). In about half the patients the MR images showed diffuse or focal areas of reduced signal intensity in the bone marrow. The observation of reduced signal areas corresponded with the pathological findings from iliac crest biopsies. To improve diagnostic accuracy, the signal intensity from a chosen region of interest was related quantitatively to a standard level.

Adult↗
PubMed1989

Magnetic resonance imaging of bone marrow in lymphoproliferative disorders: correlation with bone marrow biopsy.

In a prospective clinical study 10 normal volunteers and 30 patients with lymphoma--11 patients with Hodgkin's lymphoma and 19 patients with non-Hodgkin's lymphoma (11 low grade, 8 high grade)--were examined. Proximal femora, pelvis and lumbar spine were imaged with a 1.5 tesla superconducting MR imaging system (Siemens Magnetom). Areas of malignant infiltration in the bone marrow were clearly detected by visual and/or quantitative assessment. In most cases bone marrow involvement was demonstrated by both magnetic resonance imaging and bone marrow biopsies. However, in three of 30 patients magnetic resonance imaging showed evidence of lymphomatous involvement despite normal bone marrow histology. In one patient bone marrow cytology revealed malignant infiltration in the absence of MRI abnormalities. Thus, MRI is a sensitive method for detecting bone marrow infiltration by lymphoma.

Adult↗
PubMed1989

[MR tomography detection of bone marrow infiltration by malignant lymphomas].

In a prospective MRT study, both healthy volunteers (n = 10) and patients with Hodgkin and non Hodgkin lymphomas (n = 32) were examined (lumbar spine, pelvis and proximal femura). A biopsy from the posterior iliac crest was taken in all patients. About one half of the patients showed in MR-images diffuse or patchy areas of decreased signal intensity in the regions of the bone marrow, while the bone marrow of the volunteers showed an almost homogeneous pattern with high signal intensity. Our findings observed by MRT in bone marrow of these patients corresponds with pathological results obtained from crest biopsies. In order to improve the diagnostic accuracy, a quantitative evaluation of the signal intensities in selected ROIs, referring to a standard, was used. This method allows to correct variations of the signal intensity due to technical reasons. As our results show, this leads to a better differentiation of border-line cases. MRT has the advantage to detect localised lesions outside of the iliac crest. In cases of negative crest biopsies, but suspicious areas in MR-images, biopsies could be directed to these lesions.

Biopsy, Needle↗
PubMed1989

Response to pentostatin in hairy-cell leukemia refractory to interferon-alpha. The European Organization for Research and Treatment of Cancer Leukemia Cooperative Group.

Interferon-alpha (IFN-a) or 2'-deoxycoformycin (pentostatin; DCF) have each been shown to be highly active in hairy-cell leukemia (HCL). In this phase II study of the Leukemia Cooperative Group of the European Organization for Research and Treatment of Cancer (EORTC), the efficacy and toxicity of DCF were investigated in patients who were resistant to IFN-a treatment. Resistance was defined as: (1) progressive disease (PD) under IFN-a therapy for more than 2 months; (2) stable disease (SD) after more than 6 months of IFN-a treatment; (3) relapse within 3 months of discontinuing IFN-a; and (4) intolerance to IFN-a because of World Health Organization (WHO) grade 3 or 4 toxicity. DCF was applied at a dosage of 4 mg/m2 weekly x 3, then 4 mg/m2 every other week x 3. Responders were given a maintenance therapy once per month for a maximum of 6 months. At the time of report, 33 patients with resistant disease were evaluable for response and toxicity. Median duration of IFN-a therapy before DCF administration was 14.7 months (range, 1 to 41 months). Complete remissions (CRs) were achieved in 11 patients and partial remissions (PRs) in 15, resulting in a total response rate of 78.8%. Median interval between beginning of DCF therapy to best response was 3.9 months with a range from 2.0 to 7.0 months. Two patients who achieved PR have relapsed 7 and 14 months after cessation of DCF therapy. The median duration of response was over 11.5 months (range, over 3.0 to over 24.0 months). Three patients died within the first 6 weeks of DCF treatment: one of drug-unrelated cardiomyopathy and two of fungal pneumonia. The patients with early death (n = 3) and nonresponsive disease (n = 4) received IFN-a treatment for a longer period (median, 18.0 months) than did the 26 responsive patients (median, 10.0 months). Major side effects included nausea, skin rash, and infections and were otherwise mild. Thus, DCF is highly active in patients with HCL resistant to IFN-a.

Adult↗
PubMed1989

Plasma levels of soluble CD8 antigen and interleukin-2 receptor antigen in patients with hairy cell leukemia, relationship with splenectomy and with clinical response to therapy.

A soluble form of CD8 antigen (sCD8) has been shown to be released by activated CD8 + lymphocytes. Measurements of sCD8 may serve as an index of suppressor/cytotoxic cell activity. To assess the clinical significance of this observation in response to malignancy, we have investigated the sCD8 concentrations in 38 patients with hairy cell leukemia (HCL) not yet treated with any systemic therapy. The median plasma sCD8 level of the 20 nonsplenectomized patients was 1,025 U/ml and was significantly higher than that in the 18 patients who had previous splenectomy (median = 200 U/ml, p less than 0.0001), or in 14 normal controls (median = 350 U/ml, p less than 0.0001). Compared to controls, splenectomized patients had also significantly lower levels of sCD8 (p less than 0.01). The median concentration of soluble interleukin-2 receptor (sIL2R) in nonsplenectomized patients was 14,500 U/ml and was in the same range as in splenectomized patients (15,000 U/ml). There was no overlap in sIL2-R levels between controls (median = 300 U/ml) and patients. Investigation of serial plasma samples in 7 patients who received deoxycoformycin (DCF) and 11 patients treated with interferon alpha (IFN-alpha) showed a normalization of sCD8 levels and a decrease of sIL2R concentrations in those patients who showed hematological improvement. Normalization of sIL2R was, however, only observed in patients with complete remission. Our observation indicates that splenectomy might cause a reduction of the activation of suppressor/cytotoxic cells in patients with HCL. Treatment with either DCF or IFN-alpha also modulates the sCD8 levels to normal range. Measurements of sCD8 and sIL2-R might give more insight into the pathogenesis of HCL and serve as parameters for monitoring different phases of the disease and response to therapy.

Antigens↗
PubMed1989

Pentostatin (2'deoxycoformycin) for the treatment of lymphoid neoplasms.

Knowledge of the vital role of adenosine deaminase in lymphatic tissues has led to the development of enzyme inhibitors for treatment of lymphoid neoplasms. Deoxycoformycin is a potent ADA inhibitor and has been shown to be active in acute lymphoblastic leukemia at high doses but associated with unpredictable toxicity. In indolent lymphocytic leukemia or lymphoma with low ADA concentrations, this drug is effective at low doses with mild toxicity. The on-going EORTC trial shows that pentostatin is highly effective in hairy cell leukemia and can achieve durable complete remissions even if interferon alpha has failed. It will probably play an important role in the treatment of prolymphocytic leukemia, T- and B-cell chronic lymphocytic leukemia and Sézary syndrome.

Adenosine↗