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Biomedical subjects

M Talpaz

Publications and source records attributed to M Talpaz.

At least 325 records · Page 18Linked to original sources
PubMed1986

Modulation in vitro of immune parameters in homosexual males with the preclinical complex of symptoms related to acquired immune deficiency syndrome by azimexon.

In search of potential therapeutic agents for the acquired immunodeficiency syndrome (AIDS) among homosexual males, we studied in vitro the immunorestorative effect of azimexon in patients with this syndrome. Since a reduction in the ratio between helper inductor and suppressor/cytotoxic T-cell subsets (OKT-4/OKT-8) seems to be the hallmark of the syndrome, we measured azimexon-induced numerical changes in T-cell subsets and correlated them with changes in a simultaneously tested T-cell function as measured by the xenogeneic local graft-versus-host reaction (GVHR). Following incubation of peripheral blood mononuclear cells from 10 homosexual subjects with 10 micrograms/ml of azimexon at 37 degrees C for 1 h, the median number of T cells defined by the OKT-8 phenotype declined from 0.6 X 10(3) to 0.33 X 10(3)/mm3 (p less than 0.02), resulting in an increase in the OKT-4/OKT-8 ratio from 0.65 to 1.37 (p less than 0.01). There were no numerical changes in T cells defined by OKT-3 and OKT-4 phenotypes. Similar decreases in OKT-8-defined T cell occurred among eight heterosexual controls. The restoration of the OKT-4/OKT-8 ratio among the homosexual subjects was associated with a significant improvement in their T-cell function. Thus, the median volume of the local GVHR increased from 38.2 to 63.5 mm3 (p less than 0.02). Parallel changes in OKT-4/OKT-8 ratio and changes in local GVHR following incubation with azimexon were observed. These results suggest that azimexon may be an important immunorestorative agent. Clinical trials with this agent in patients with AIDS or its preclinical complex of symptoms seem warranted.

Acquired Immunodeficiency Syndrome↗
PubMed1986

C-sis and C-abl expression in chronic myelogenous leukemia and other hematologic malignancies.

Cellular oncogenes have been localized at the breakpoints of characteristic chromosomal rearrangements occurring in certain hematologic malignancies. This has been reported to result in aberrant expression of the involved oncogenes. Over 90% of chronic myelogenous leukemia (CML) is characterized by a reciprocal translocation that brings c-abl from chromosome 9 to chromosome 22, and c-sis from chromosome 22 to chromosome 9. To investigate the possible role of these two oncogenes in the leukemic process, we studied their expression in a number of fresh samples obtained from patients with various forms of leukemia, by Northern blot analysis using c-onc probes. Seven of 24 samples obtained from patients with either CML or chronic myelomonocytic leukemia expressed a normal 4.0-kilobase (kb) c-sis transcript. C-sis expression was found only in the accelerated/blast phases but not in the chronic phase of CML. All of the CML Philadelphia chromosome-positive (Ph1+) samples expressed an aberrant 8-kb c-abl transcript. The expression of c-sis in

Humans↗
PubMed1986

Changes in granulocyte-monocyte colony-forming cells among leukocyte-interferon-treated chronic myelogenous leukemia patients.

Myeloid cytoreduction leading to hematologic remissions is frequently seen among patients with chronic phase Philadelphia-positive chronic myelogenous leukemia (CML Ph') treated with leukocyte interferon (IFN-alpha). In order extend our understanding of the events associated with interferon-induced myeloid cytoreductions, we have examined the changes in granulocyte-monocyte colony-forming cells (GM-CFC) in such CML Ph' patients. A total of 28 CML Ph' patients in hematologic remissions following IFN-alpha treatment had a median GM-CFC of 12 (range, 0-182)/1 X 10(5) bone marrow cells. This was significantly lower than the median GM-CFC of 104 (range, 44-815; p less than 0.01) in 22 untreated or minimally treated CML Ph' patients and the median of 72 (range, 30-204; p less than 0.05) in 18 normal controls. A gradual decline in the GM-CFC numbers from a median of 105 to a median of 1.8 was seen in six responding patients who were studied serially over a median period of 7.5 months. In these patients, we also observed a profound decline in the number of aspirated bone marrow nucleated cells and a decline in the bone marrow cellularity. The effect of treatment interruption for a median of 13 days was studied in five patients. In three of the patients who had received IFN-alpha for less than or equal to 6 months, treatment interruption resulted in rapid increase in the GM-CFC, while the GM-CFC did not change in the remaining two patients, who received IFN-alpha for one and two years. We conclude that treatment of CML patients with IFN-alpha resulted in a progressive decline of the bone marrow GM-CFC. The initially expanded pool of committed myeloid stem cells declines gradually, and at the time of hematologic remission the number of GM-CFC/10(5) nucleated bone marrow cells is lower than that of normal controls. In the early phases of IFN-alpha treatment, this inhibitory effect is rapidly reversible, but it seems to persist when the treatment is extended over more than one year.

Bone Marrow↗
PubMed1985

Immune thrombocytopenia following alpha-interferon therapy in patients with cancer.

Immune thrombocytopenia occurred in five patients with cancer receiving alpha-interferon. The median pretreatment platelet count was 217,000/cu mm, which fell to a median of 12,000/cu mm after a median of 25 days of interferon therapy. All had normal numbers of megakaryocytes, with dysplasia noted in three; all four who were tested had platelet-associated immunoglobulin. All had normalization of platelet counts with prednisone therapy. Four tolerated re-treatment with interferon, two with concurrent prednisone administration and two others following splenectomy. Immune thrombocytopenia should be considered in patients who become thrombocytopenic during interferon therapy.

Adult↗
PubMed1985

Down-regulation of peripheral blood cell interferon receptors in chronic myelogenous leukemia patients undergoing human interferon (HuIFN alpha) therapy.

Our interest in studying interferon (IFN) receptor activity in peripheral blood cells (PBCs) from patients with chronic myelogenous leukemia (CML) receiving therapeutic doses of partially purified leukocyte IFN (IFN alpha) stems from a need for more adequate monitoring of IFN therapy. The binding of 35S-labelled recombinant DNA-derived leukocyte clone A IFN (35S-rIFN alpha A) to PBCs from 8 patients with CML was determined before and during IFN alpha treatment. The patients' mean pretherapy binding level (0.049 femtomoles of bound 35S-rIFN alpha A) was in the range of values obtained from 4 normal donors (mean of 0.054 femtomoles bound). Within 24 hr of the first IFN alpha dose, the mean femtomoles bound decreased 10-fold and remained low during the course of IFN alpha treatment. In I/I patient, we demonstrated that this decreased binding was due to a loss in number of IFN receptors. The apparent number of receptors after 5 doses of IFN alpha decreased from approximately 600 receptors per cell at pretherapy to approximately 75 receptors per cell, with no difference in the dissociation constants (1.13 X 10(-10)M, 0.968 X 10(-10)M, before and during treatment, respectively). In 4/4 patients, we demonstrated indirectly that the decreased binding was not due to receptor saturation as a result of residual circulating IFN alpha. In 3/3 patients, we demonstrated a gradual recovery of binding capacity after incubating the patients' PBCs at 37 degrees C. Within 2-7 days in vivo recovery of binding, comparable to pretherapy levels, was observed in 3/3 patients whose IFN alpha therapy was discontinued. Combining all these data, we conclude that in both responding and nonresponding patients with CML, IFN alpha exposure induces decreased binding of labelled IFN when a single recombinant DNA-derived IFN species is used. We feel the supporting data indicate that the decreased binding capacity may be due to receptor down-regulation. In the limited number of patients studied thus far, there was no correlation between clinical hematologic response and occurrence of down-regulation, however, down-regulation of cell surface receptors may be required to sustain a biological effect. Further studies of both the kinetics of down-regulation and activation of key enzyme systems are required to fully evaluate the relevance of these findings.

Blood Cells↗
PubMed1985

The human cellular abl gene product in the chronic myelogenous leukemia cell line K562 has an associated tyrosine protein kinase activity.

Three antisera against the mouse v-abl gene product were used to identify two potential human c-abl gene products in the chronic myelogenous leukemia cell line K562. Two antipeptide sera were generated in rabbits using the predicted amino acid sequence of the mouse v-abl gene product. One antiserum was made against a polypeptide overlapping the in vivo tyrosine phosphorylation site of murine P120gag-abl and what is believed to be a homologous tyrosine phosphorylation site of the predicted normal human c-abl gene product (v-abl 263-280). The second antipeptide serum, abl 389-403, was generated against a predicted hydrophilic peptide of the v-abl gene product. Immunoprecipitation from K562 cells metabolically labeled with [32P]orthophosphate by a mouse tumor regressor and abl 389-403 antipeptide sera detected two proteins of 190,000 and 240,000 Da. Both proteins were labeled primarily at serine and, to a much lesser extent, at tyrosine residues. Immune complex kinase assays using conditions that allow the tyrosine phosphorylation of P120gag-abl showed that in vitro phosphorylation of P190 and P240 occurs primarily at tyrosine residues. The detection of these enzymatically active human c-abl gene products is a rare observation which may be in part attributed to the c-abl gene translocation from chromosomes 9 to 22 occurring in the vast majority of chronic myelogenous leukemia patients.

Abelson murine leukemia virus↗
PubMed1985

Suppression of clonal evolution in two chronic myelogenous leukaemia patients treated with leucocyte interferon.

Two patients with Philadelphia chromosome-positive (Ph1+) chronic myelogenous leukaemia (CML) were treated with human leucocyte interferon (HuIFN-alpha). Karyotypic changes in addition to the Ph1 chromosome developed in these patients before the start of HuIFN-alpha treatment. In one patient the administration of HuIFN-alpha resulted in clinical haematological remission and stable suppression of the secondary Ph1 clone. The second patient was in myeloid blastic crisis when given HuIFN-alpha. While she was receiving HuIFN-alpha, suppression of the blast cell population in the bone marrow occurred. The subsequent cytogenetic changes included a near-complete suppression of a secondary Ph 1 clone of cells carrying a deletion in the short arm of chromosome 7 and partial population of the bone marrow with primary Ph1 clone. These observations suggest a potential role for interferons in altering the progressive course of CML.

Adult↗
PubMed1985

Preferentially expressed genes in chronic myelogenous leukemia.

The predominant circulating cells in chronic myelogenous leukemia (CML) morphologically resemble normal myeloid precursors; however, certain characteristics indicate the two are not identical. Approximately 88% of the patients with clinically typical CML present with a cytogenetic abnormality known as the Philadelphia chromosome (Ph1). Additionally, the leukocyte alkaline phosphatase (LAP) value is decreased in CML. To investigate if there are selected genes expressed in the CML cell population, poly(A+)RNA from a chronic-phase, Ph1-positive CML patient was used for construction of a complementary DNA (cDNA) library. Recombinant clones representing moderately to abundantly transcribed sequences were selected by annealing [32P]-cDNA transcribed from homologous RNA to the library sequences and assessing radioactivity in the hybrids. From an initial 729 colonies, 417 (57.2%) displayed a hybridization signal more intense than controls, indicating these recombinant plasmids contained sequences homologous to moderately or highly expressed RNAs from this particular patient. Screening of the 417 clones--utilizing 32P-cDNAs derived from normal human placenta, an acute myelomonocytic leukemia (AMML), and two other CML samples--was used to select clones likely to represent sequences preferentially expressed in CML. Sixteen recombinants were initially selected that repeatedly failed to display hybridization with the placenta and AMML-derived probes. Further analysis of eight of these clones indicated that six contain sequences preferentially expressed in CML. One clone, C-A3, has been studied with 63 different RNA samples. This sequence is found to be highly expressed in peripheral blood cells from the chronic phase of both Ph1-positive and Ph1-negative CML as well as in a Ph1-positive acute myelogenous leukemia (AML). Expression is reduced in lymphoblastic crisis of CML (L BC-CML) and essentially absent in myeloblastic crisis of CML (M BC-CML). While preliminary, the results suggest that this probe may be useful as an aid in diagnosing Ph1-negative CML and in distinguishing M BC-CML from L BC-CML and Ph1-positive AML.

Adolescent↗
PubMed1985

Chronic myelogenous leukemia: a multivariate analysis of the associations of patient characteristics and therapy with survival.

The prognostic importance of patient pretreatment clinical and laboratory features was investigated in a group of 303 patients with Philadelphia chromosome-positive benign-phase chronic myelogenous leukemia. Intensive chemotherapy was given to 97 patients, and 78 underwent an early elective splenectomy. The overall median survival time, dated from hospital admission, was 39 months. Patient characteristics associated with shortened survival were age 60 years or older, black race, the presence of hepatomegaly, splenomegaly, symptoms, weight loss, and poor performance status. Adverse blood and bone marrow parameters were anemia, thrombocytosis or thrombocytopenia, a high proportion of peripheral blasts plus promyelocytes or of basophils, a high proportion of marrow blasts or basophils, decreased marrow megakaryocytes, and cytogenetic abnormalities in addition to the Philadelphia chromosome. Several of these factors were interrelated. A multivariate regression analysis demonstrated that the combination blood basophilia, race, additional cytogenetic abnormalities, age and marrow basophilia had the strongest predictive relationship to survival time. This resulted in a model segregating patients into low-, intermediate-, and high-risk groups, with median survivals of 53, 39, and 25 months, respectively. Another model was derived that did not include the marrow features and identified splenomegaly and platelet counts as adding to the prognosis prediction by blood basophilia, race, and age. Evaluation of the effect of therapy, after adjusting for differences in prognostic characteristics, showed that intensive chemotherapy was associated with survival prolongation among patients at intermediate and high risk of death. We conclude that a combination of pretreatment factors identifies different risk subcategories in patients with chronic myelogenous leukemia and is helpful in assessing overall prognosis and treatment effect.

Adult↗
PubMed1985

Pharmacokinetics, single-dose tolerance, and biological activity of recombinant gamma-interferon in cancer patients.

We report a clinical study of the pharmacokinetics, toxicity, and biological activity of i.v.- and i.m.-administered recombinant gamma-interferon (rIFN-gamma) consisting of 143 amino acids. Ten patients with metastatic cancer were given rIFN-gamma at doses of 0.01 to 2.5 mg/sq m by alternating i.m. and i.v. bolus injections with a minimum intervening period of 72 h. After i.v. administration, rIFN-gamma was cleared monoexponentially with a short half-life of 25 to 35 min as determined by bioassay and enzyme immunoassay. After i.m. injection, a longer half-life of 227 to 462 min was measured by enzyme immunoassay. Serum titers were detected by bioassay only at high doses, suggesting partial loss of antiviral activity at the i.m. site. However, other biological effects were retained as evidenced by fever, chills, and fatigue after both routes of administration and granulocytopenia after i.m., but not i.v., doses. Two of ten patients showed objective evidence of tumor regression. These data suggest that further studies with i.m. as well as prolonged i.v. infusions of rIFN-gamma are indicated.

Half-Life↗
PubMed1984

Chronic immune stimulation by sperm alloantigens. Support for the hypothesis that spermatozoa induce immune dysregulation in homosexual males.

Putative, sperm-induced allogeneic immunization was correlated with immune dysregulation in a study of 30 asymptomatic, monogamously paired homosexual males. Evidence for allogeneic immunization existed among 19 of 26 homosexual males who were anal sperm recipients. No evidence for any form of alloimmunization was found in four exclusive sperm donors. Immune dysregulation in the form of a reduced effector/suppressor T-cell ratio (Te/Ts less than 1.0) was exclusively documented in eight anal-sperm-recipient homosexual males, five of whom also manifested evidence for allogeneic immunization. In three of those, immune dysregulation was further manifested by functional T-cell deficiency in the form of a subnormal (less than 50 cu mm) local graft-v-host reaction. Similar evidence for alloimmunization was associated with a reduced Te/Ts ratio (0.85) in the female of a heterosexual couple who routinely practiced anal intercourse. Based on these findings, we suggest that chronic, repeated exposure to sperm during anal intercourse results in a high frequency of allogeneic immunization and may play an important role in the development of acquired immune dysregulation among homosexual males.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Low natural killer cell activity in the bone marrow of healthy donors with normal killer cell activity in the peripheral blood.

We have investigated the natural killer (NK) cell activity in peripheral blood and in bone marrow of nine normal donors. It was found that Ficoll-Hypaque (FH)-separated cells from the bone marrow collected in small (1 ml) aliquots had very low NK activity compared with normal activity in the peripheral blood of the same donor (mean +/- SD: 4.2% +/- 2.5% vs 25.1% +/- 15%, P less than 0.01). This difference was maintained for cells bearing receptors for sheep erythrocytes (E+) in both tissues (4.3% +/- 2.37% vs 15%+/-12.6%, P less than 0.01) or E- cells (2.5% +/- 2.86% vs 20.4% +/- 19.5%, P less than 0.01). Also, in bone marrow cells with Fc receptors for IgG (Fc gamma+) neither E+ nor E- had significant NK activity, in contrast to the peripheral blood, where significant NK cell activity was detectable in the Fc gamma + cells, either E+ or E- (1.9% +/- 1.2% and 1.3% +/- 1.4% vs 16.1% +/- 10.3% and 12.8% +/- 7.4%, respectively, P less than 0.01 for both). Our data indicate that bone marrow obtained with a low degree of blood contamination from normal donors has very low NK activity with no significant increase in any of the several fractions tested.

Bone Marrow Cells↗
PubMed1983

Rheumatoid factors in the sera of patient with gastrointestinal carcinoma.

One hundred and nineteen patients with gastrointestinal (GI) malignancy (80 colorectal, 25 gastric and 14 pancreatic carcinoma) were studied for rheumatoid factors (RF), antinuclear antibodies (ANA) and immunoglobulin levels and the findings correlated with size of tumor, stage of disease and survival. Twenty three (19.3%) of the patients were RF seropositive compared to 5.7% of 70 matched controls (P = 0.02). In two thirds of the seropositive patients RF were detected prior to the initiation of treatment. The proportion of RF seropositivity increased significantly in patients with tumors larger than 4 cm and in patients with Stage D disease. The authors found a high incidence of ANA in the patients: 32.4% compared to 8% in normal subjects (P less than 0.01), but the proportion of RF in this group was not significantly different. Survival distributions of the RF positive cases were different from that of the other patients (18 versus 25 months median survival); however, this was not statistically significant. These findings indicate that RF in GI cancer patients sera is not rare and can be related mainly to "tumor load," although not considerably affecting survival.

Aged↗
PubMed1983

Objective evaluation of local xenogeneic graft-versus-host reaction by computerized radioisotope imaging (CRI).

The local xenogeneic graft-versus-host reaction (GVHR) assay has been used clinically to evaluate cellular immune competence and experimentally to monitor the immunomodulatory effects of several drugs. By employing a computerized radioisotope imaging (CRI) technique, we were able to perform the assay with smaller numbers of mononuclear cells (MNC) and to rid it entirely of any bias. Measuring the local GVHR by CRI compares well with the conventional measurement of the volume (correlation coefficient r = 0.619; P less than 0.001). A clear-cut distinction was documented between normal donors and cancer patients (P less than 0.001) when 10 X 10(6) or more MNC were used in the assay. This is an improvement over the previous, conventional testing of local GVHR which required injection of 20 X 10(6) MNC in order to achieve a similar resolution. The indications for the presence of immune competence have therefore been redefined using the local GVHR index as determined by CRI according to the scale of MNC injected. Thus, immunocompetence is considered present if the CRI index is greater than or equal to 1.2 for 10 X 10(6) MNC, greater than or equal to 2.0 for 15 X 10(6) MNC and greater than or equal to 2.6 for 20 X 10(6) MNC.

Animals↗
PubMed1983

Immune restoration and/or augmentation of local graft versus host reaction by traditional Chinese medicinal herbs.

The in vitro restorative effect of aqueous extracts from two traditional Chinese medicinal herbs were studied in 19 cancer patients and in 15 normal healthy donors. Using the local graft versus host (GVH) reaction as a test assay for T-cell function, the extract from astragalus membranaceus (10 microgram/ml) induced a restored reaction in nine of ten patients with an increase in local GVH reaction from 18.2 plus/minus 15.8 mm3 to 112.9 plus/minus 94.2 mm3 (P less than 0.01). The extract from ligustrum lucidum, likewise effected an immune restoration in nine of 13 cancer patients with an increase in local GVH reaction from 32.3 plus/minus 36.1 mm3 to 118 plus/minus 104.9 mm3 (P less than 0.01). This degree of immune restoration appears to be complete as it equals the local GVH reaction observed among untreated mononuclear cells from normal healthy donors (82.8 plus/minus 41.1 mm3, P greater than 0.1). These results suggest that both extracts of the traditional Chinese medicinal herbs contain potent immune stimulants which may provide the rational basis for their therapeutic use as biological response modifiers.

Adjuvants, Immunologic↗
PubMed1983

The immune restorative effect of Isoprinosine administration on the local graft-versus-host reaction of cancer patients.

The immunorestorative effect of Isoprinosine (ISO) in vivo on T-cell-induced local graft-versus-host reaction (GVHR) was analyzed in 60 cancer patients randomized into three groups: 20 patients received 1 g/day ISO orally for 7 days, 20 patients received 4 g/day ISO for 7 days, and 20 patients received no treatment for 7 days. The local GVHR was assessed before and after the 7 days of treatment (or no treatment). A significant augmentation of the local GVHR was observed among the ISO-treated patients (44.1 +/- 19.1 vs 61 +/- 37.1 for 1 g ISO, P less than 0.05; 42.1 +/- 20.1 vs 58.9 +/- 23.8 for 4 g of ISO, P less than 0.01). This was not so for patients who received no treatment (38.5 +/- 20.4 vs 38.3 +/- 21.2; P greater than 0.1). Nine patients treated with 1 g of ISO and 5 treated with 4 g of ISO/day, who were initially characterized by a negative local GVHR (less than 50 mm3), converted to a positive reaction (greater than or equal to 50 mm3) compared to none of the patients who received no treatment. Two patients treated with 1 g of ISO and 2 patients treated with 4 g, who initially had a positive GVHR, demonstrated further augmentation (greater than or equal to 50% increase) in the GVHR after 7 days of treatment. In 2 patients (one in each treated group) the ISO induced a suppression of the GVHR from positive to negative. Incubation of the patients' lymphocytes in vitro with ISO (100 micrograms/ml X 1 hr) failed to induce augmentation of the GVHR and did not correlate with the in vivo effect in the same patients. These results demonstrate an immunomodulatory effect of ISO in cancer patients and lend further support to the use of this drug as an immunomodulating therapy among cancer patients.

Animals↗
PubMed1983

Human leukocyte interferon to control thrombocytosis in chronic myelogenous leukemia.

Nine patients with refractory chronic myelogenous leukemia and severe symptomatic thrombocytosis (greater than or equal to 1 X 10(6) platelets/mm3) were given partially purified human leukocyte interferon-alpha. A significant decline in platelet counts, from a mean (+/- SE) of 1.71 +/- 0.53 X 10(6)/mm3 to a mean of 0.52 +/- 0.24 X 10(6)/mm3 (p less than 0.01), resulted in all patients. Maintenance of low platelet counts was achieved in two patients for more than 143 and 300 days, respectively. Treatment with human leukocyte interferon-alpha was stopped in the remaining patients because of increases in the leukocyte count, toxicity, or both. Our preliminary observations suggest that human leukocyte interferon-alpha may significantly alleviate progressive thrombocytosis in advanced chronic myelogenous leukemia. Further studies of human leukocyte interferon-alpha and chemotherapeutic agents are indicated.

Adult↗