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Biomedical subjects

O J Martelo

Publications and source records attributed to O J Martelo.

At least 19 recordsLinked to original sources
PubMed1993

Enzymatic and immunohistochemical evaluation of tyrosine phosphorylation in breast cancer specimens.

Using a synthetic peptide substrate, tyrosine protein kinase (TPK) activity was measured in 21 tumors from patients with histologically confirmed breast cancer and in five normal breast tissues from patients undergoing reduction mammoplasty. In 20 of 21 cancer specimens, tumor was available to assess phosphotyrosine (PT) immunohistochemically. Breast cancer specimens possessed significantly more TPK activity than normal breast tissues (Cancer = 43.9 +/- 3.1 pm/mg protein/min, [Mean +/- S.E.M.]; Normal = 3.4 +/- 0.9, p < 0.001). TPK activity was higher in the clinically more aggressive infiltrating ductal cancers compared to the less aggressive intraductal cancers (Infiltrating = 55.9 +/- 5.8; Intraductal = 17.2 +/- 3.4, p < 0.01). TPK activity in tumors with both infiltrating and intraductal histology was intermediate (34.0 +/- 7.2). Significant correlation existed between membrane TPK enzymatic activity and PT expression by immunohistochemistry. There was no relationship between estrogen or progesterone receptor status and TPK activity or PT; however, TPK activity from node negative breast cancer tissue was significantly less than from node positive specimens (p < 0.01). We conclude that breast cancer specimens possess elevated amounts of TPK which correlate with PT expression, and that increased tyrosine phosphorylation appears to correlate with the biologic aggressiveness of the malignant tumor.

Breast↗
PubMed1992

Late intensification therapy in adult acute lymphoid leukemia. The Southeastern Cancer Study Group Experience.

One hundred ninety-two evaluable patients were treated on a multicenter protocol for adult acute lymphoid leukemia to determine in a prospective randomized fashion if late intensification chemotherapy beginning after about six months of treatment would improve remission duration and survival. The complete remission rate was 60%. The median remission duration was 13.5 versus 25.9 months (P = 0.31) for standard maintenance therapy and late intensification, respectively, and the median survival was 17.5 versus 34.7 months (P = 0.19) respectively. Although there was a suggestion that the late intensification strategy was helpful, relapse proved to be common during the early phases of treatment; thus, insufficient numbers of patients were available at the randomization point to conclusively address the possible value of late intensification. Intensive therapy earlier in remission should be evaluated.

Adolescent↗
PubMed1992

Increased tyrosine protein kinase activity in hairy cell and monocytic leukemias.

Tyrosine protein kinases (TPK) help regulate cellular growth and differentiation. Several proto-oncogenes encode for protein products with associated tyrosine kinase activity. An assay for TPK activity was performed in cell extracts using a synthetic peptide substrate and [32P] adenosine triphosphate (ATP). TPK activity was elevated in K-562 cells, which possess an amplified c-abl oncogene, compared to normal blood mononuclear cells (K-562 = 9.37 +/- 1.72 [mean +/- standard deviation] pmol ATP/10(6) cells/min; normal = 1.14 +/- 0.46, p less than 0.01). TPK activity was measured in peripheral blood mononuclear cells from patients with hairy cell leukemia (HCL), myelomonocytic leukemia (MOL), acute myeloblastic leukemia (AML), and chronic lymphocytic leukemia (CLL). In patients with clinically active disease, elevated TPK activity was measured in mononuclear cells from five HCL patients (range 3.76-24.15) and from seven MOL patients. These elevated levels appeared to parallel disease activity, as low levels of TPK activity were measured in patients with inactive (treated) disease. Low levels of TPK were measured in mononuclear cells from active AML and CLL patients. Elevated TPK levels in patients with HCL and MOL may reflect the overexpression of a proto-oncogene or increased growth factor activity in immature or rapidly dividing leukemic cells. Serial TPK levels in HCL and MOL patients correlated with change in disease activity.

Humans↗
PubMed1989

Ifosfamide plus doxorubicin in metastatic adult sarcomas: a multi-institutional phase II trial.

Between April 1986 and March 1987, 42 patients with advanced sarcoma were entered in this multi-institutional trial evaluating ifosfamide plus doxorubicin. The majority of patients had leiomyosarcoma and malignant fibrous histiocytoma although two patients with sarcomas of osseous origin were included. Doxorubicin was administered at a dosage of 60 mg/m2 by continuous push and ifosfamide 5.0 g/m2 by continuous infusion over 24 hours with mesna (7.5 g2 over 36 hours) with courses repeated every 3 weeks until progression, toxicity cumulative doxorubicin dosage of 450 mg/m2. Overall, 15 (36%) patients demonstrated objective remissions including three complete and 12 partial remissions (95% confidence limits, 21.5% to 52.0%). The median duration of remission was 7.0 months and the median survival time for all eligible patients was 8.0 months. Toxicity was predominantly hematologic with the median leukocyte nadir being 1,300 per microliter of blood and documented sepsis in six patients. These data support activity for ifosfamide plus doxorubicin in patients with advanced sarcoma, but the actual contribution of ifosfamide needs to be evaluated through prospective randomized trials which are currently underway.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

The 24-hour posttransfusion survival and lifespan of autologous baboon red cells treated with inositol hexaphosphate-polyethylene glycol or inositol hexaphosphate-adenosine triphosphate-polyethylene glycol to decrease oxygen affinity.

Baboon red cells were treated to reduce oxygen affinity by an osmotic-pulse procedure using dimethyl-sulfoxide. Inositol hexaphosphate (IHP) alone or IHP and adenosine triphosphate (ATP) were incorporated into the red cells in the presence of polyethylene glycol (PEG). The procedure produced variable increases in the red cell P50 value, i.e., the partial pressure of oxygen at which 50% of the hemoglobin was saturated. The effect of treatment of autologous baboon red cells on the 24-hour posttransfusion survival value and lifespan T50 value was measured using a double-label procedure. The data demonstrate that the increase in the P50 value of treated red cells was negatively correlated with the 24-hour posttransfusion survival value; the higher the P50 value, the poorer the 24-hour posttransfusion survival value. The 24-hour posttransfusion survival value for nontreated baboon red cells was 90% and the T50 value was 14 days. The IHP-ATP-PEG-treated red cells had significantly higher red cell ATP levels than did IHP-PEG-treated red cells. The 24-hour posttransfusion survival value was 68% for the IHP-ATP-PEG treated red cells and 52% for the IHP-PEG-treated red cells when the increase in P50 ranged from 10 to 20 mm Hg; the lifespan T50 value for both the IHP-ATP-PEG-treated red cells and the IHP-PEG-treated red cells was 15 days. Osmotic pulse treatment produced significant red cell injury manifested by the 24-hour posttransfusion survival value. However, modification of the RBC with IHP-PEG or IHP-ATP-PEG to decrease hemoglobin affinity for oxygen did not affect their lifespan.

Adenosine Triphosphate↗
PubMed1988

The anemia of sarcoidosis.

Anemia and leukopenia have been reported in sarcoidosis. In order to characterize the prevalence and association with disease activity, 75 patients with active pulmonary sarcoidosis were studied. One or more hematologic abnormalities were identified in 87% of patients studied. Anemia was present in 21 patients (28%), and bone marrow examination in 17 anemic patients revealed noncaseating granulomas in 9 patients and absent iron stores in 8 patients. The bone marrow aspirates did not show characteristics seen in other anemias of chronic disease, such as tuberculosis. In the majority of unexplained anemia cases, hemoglobin levels normalized with prednisone treatment. Forty-one of 75 patients (55%) had lymphopenia. Anemia found in patients with active sarcoidosis was associated with noncaseating granulomas in the bone marrow and an improvement with steroid therapy.

Adult↗
PubMed1987

Immunohistochemical classification of acute leukemias using peripheral blood smears.

Immunophenotypic classification of the acute leukemias (AcL) is of well documented value in those of lymphoid or uncertain origin and of increasing importance in those of nonlymphoid origin. Most of these studies have been performed on viable cell suspensions. To study the efficacy of a simpler immunohistochemical approach to the classification of the acute leukemias requiring only peripheral blood smears, 15 AcL (including three CGL-BC) were studied using an immunoalkaline phosphatase method and a panel of anti-lymphoid and anti-myeloid monoclonal antibodies. Routine cytochemistries were also performed (Sudan black, PAS). Using immunohistochemistry, five cases marked as common ALL (four were undifferentiated by cytochemistry, one ALL), eight cases as ANLL (all ANLL by cytochemistry) and two cases marked only with anti-HLA-DR (AUL by cytochemistry). These results show that immunophenotypic analysis of AUL, ALL and ANLL can be successfully performed even when only air dried peripheral blood smears are available.

Histocytochemistry↗
PubMed1986

Effect of inositol hexaphosphate on the transient behavior of red cells following a DMSO-induced osmotic pulse.

An osmotic pulse can be used to incorporate inositol hexaphosphate (IHP) into red cells. The pulse is induced by equilibrating a red cell suspension with DMSO and then rapidly diluting with an isotonic IHP solution. Since IHP binds to hemoglobin and lowers the affinity for oxygen, this method may find application in the preparation of low-affinity cells for experimental and clinical use. The experiments reported here examined the dynamic changes of several red cell variables immediately following the osmotic pulse. The effect of IHP, which has been shown to dissociate red cell cytoskeletons, was evaluated by comparison with a matched phosphate-buffered saline (PBS) diluent. Red cell morphology, volume, and hemoglobin permeability were studied by fixing the cells at times ranging from 0.06 to 300 sec after dilution. Mechanical fragility was measured by subjecting the cells to a short period of shear stress at the same times after dilution. With both diluents, the cells underwent a rapid increase in volume followed by a return towards normal volume with a maximum at less than 250 msec. With IHP diluent, the period of hemoglobin permeability immediately followed the size peak and was completed by about 1 sec after dilution. PBS also induced a second leakage at longer times (10-120 sec), which resulted in a morphological dichotomy with ghosts and intact cells. The choice of diluent also affected sensitivity to shear stress. The IHP-treated cells had a mechanical fragility maximum at about 1 sec. The PBS-treated cells exhibited no enhanced mechanical fragility. An unexpected result was the inhibition of the second phase of lysis in PBS-treated cells by a properly timed shear stress.

Cell Membrane Permeability↗
PubMed1986

Phase II evaluation of cisplatin, bleomycin, and vindesine in advanced squamous cell carcinoma of the esophagus: a Southeastern Cancer Study Group Trial.

Adults with advanced, measurable, squamous cell carcinoma of the esophagus were treated with a combination of cisplatin, bleomycin, and vindesine. Of 27 evaluable patients, seven (29%) had partial response, all occurring within the first two cycles of therapy. Of 13 patients receiving more than two cycles, only five completed the five planned cycles of therapy and did not progress while receiving the additional three cycles. Granulocytopenia was the major toxic effect observed, with 52% of the patients having neutrophil counts less than 1000/mm3. Findings suspicious for bleomycin pulmonary toxicity were observed in two evaluable patients and bleomycin toxicity was pathologically confirmed in one ineligible patient. Based on the results of this study, this regimen cannot be recommended for routine use in patients with advanced esophageal cancer. The search for more effective and less toxic regimens should continue.

Aged↗
PubMed1985

Follicular center-cell lymphoma with plasmacytic differentiation, monoclonal paraprotein, and peripheral blood involvement. Recapitulation of normal B-cell development.

A patient with a nodular and diffuse small-cleaved follicular center-cell lymphoma that exhibited definite plasmacytic differentiation, a related monoclonal gammopathy, and circulating population of small lymphocytes is presented. Aside from showing that the presence of numerous plasma cells is not a reliable criterion for the diagnosis of a reactive follicular proliferation, the case is an example of a lymphoma without a block in maturation. The "neoplastic" B-cells show development to follicular center cells and beyond, to functioning plasma cells, and probably also to recirculating "memory" cells. It also suggests that plasmacytoid lymphocytic lymphomas (Lukes-Collins classification) might represent a heterogeneous group of lymphoid neoplasms with some closely related to follicular center-cell lymphomas and others more closely related to small lymphocytic lymphoma/B-cell chronic lymphocytic leukemia.

Antibodies, Monoclonal↗
PubMed1984

Preparation of low-affinity red cells with dimethylsulfoxide-mediated inositol hexaphosphate incorporation: hemoglobin and ATP recovery using a continuous-flow method.

Incorporation of IHP into red cells decreases oxygen affinity as a result of the binding of this compound to the 2,3-DPG site of hemoglobin. This investigation describes a continuous-flow method which utilizes the osmotic pulse technique to transport IHP into RBC. Using this procedure, it is possible to obtain a significant increase in P50 while maintaining in vitro cellular integrity. For example, IHP incorporation sufficient to cause an increase in the P50 of 20 mm Hg may be achieved with recovery of approximately 75% of the hemoglobin and with maintenance of ATP levels compatible with good viability. The continuous-flow method allows uniform treatment of large, unit-size volumes of red cells with a relatively small quantity of reagents. The final cell product is macrocytic/hypochromic with an increased number of stomatocytes.

Adenosine Triphosphate↗
PubMed1983

Incorporation of inositol hexaphosphate into red blood cells mediated by dimethyl sulfoxide.

Inositol hexaphosphate (IHP) binds to deoxyhemoglobin and markedly decreases the affinity of hemoglobin for oxygen. We introduce here a method for incorporating this polyphosphate into erythrocytes, thus preparing very low affinity cells for use in respiration research. The method uses dimethyl sulfoxide (DMSO) to facilitate entry of IHP. The cells are exposed to a high concentration of DMSO which is rapidly diluted with IHP solution. During this dilution the cells become leaky and IHP enters. The influence of several variables at each step of the process has been investigated and the data support a transient osmotic gradient mechanism for IHP incorporation.

Dimethyl Sulfoxide↗
PubMed1982

Cobalamin (vitamin B12) deficiency detection by urinary methylmalonic acid quantitation.

A study was made to assess the value of cobalamin deficiency detection through quantitation of urinary methylmalonic acid (MMA). Urinary MMA was measured in 1118 patients suffering from megaloblastic anemia, other anemias, elevated red cell mean corpuscular volume, or unexplained neurologic disorders. Patients without proven cobalamin deficiency had urinary MMA levels less than 20 micrograms/ml. All patients (n = 27) confirmed to have cobalamin deficiency showed MMA levels greater than 20 micrograms/ml. Data are presented showing the Schilling test results, the comparison of serum cobalamin to urinary MMA levels, and other basic hematologic data. MMA levels are a good indication of cobalamin distribution and function since they are directly related to a cobalamin-dependent metabolic pathway. With rapid, reliable quantitation by mass spectrometry, urinary MMA can now be a useful clinical test.

Adult↗
PubMed1982

Sickling as a function of oxygen delivery: effect of simulated transfusions of stored, fresh and inositol-hexaphosphate-loaded (low affinity) red cells.

Low oxygen affinity red cells were prepared by incorporating inositol hexaphosphate (IHP) into red blood cells (rbc) by means of a liposomal transport system. The effect of in vitro simulated exchange transfusions on sickling was studied with buffered red cell suspensions containing 50% SS cells and 50% test cells. Test rbc were either stored cells with high oxygen affinity, fresh cells with normal affinity or IHP-loaded cells with decreased affinity. Oxygen equilibrium curves and percentage sickling as a function of PO2 were determined and the data analyzed in terms of percentage sickling as a function of oxygen delivery. Our simplified analysis shows that simulated exchange transfusion with stored and, to a lesser extent even with fresh blood, results in a decreased venous PO2 and increased sickling of the remaining SS cells. In contrast, transfusion with IHP-loaded cells results in higher venous PO2 values and less sickling throughout the range of oxygen delivery. Thus, the transfusion of IHP-loaded cells may result in less sickling of the remaining SS cells in addition to the normal dilutional effect.

2,3-Diphosphoglycerate↗
PubMed1981

Activation and partial characterization of a human reticulocyte heme-dependent eIF-Z alpha kinase.

An inhibitor of globin translation initiation that is activated under heme-deficient conditions and whose activity is associated with phosphorylation of the 38,000 dalton (alpha) subunit of the initiation factor eIF-2 has been previously described in rabbit reticulocytes. We describe here an analogous enzyme in human reticulocytes. The human enzyme can be activated in intact reticulocytes under conditions of heme synthesis inhibition or by incubation of lysates in the absence of hemin. Addition of hemin to lysates prevents activation of the eIF-2 alpha kinase. The partially purified kinase is associated with inhibition of globin synthesis in a rabbit cell-free system and phosphorylates the small subunit of highly purified rabbit eIF-2. We conclude that human reticulocytes contain a protein kinase that is analogous to the rabbit HCR and that may play a role in clinical heme deficiency states. l

Enzyme Activation↗