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Biomedical subjects

J P Hester

Publications and source records attributed to J P Hester.

At least 37 records · Page 2Linked to original sources
PubMed1991

Tumor necrosis factor and c-fos expression in human peripheral-blood monocytes: expression is dependent on stage of in vitro differentiation.

The differentiation of monocytes and macrophages both in vitro and in vivo can be characterized by the modulation of specific functional and molecular phenotypes. We have determined in human peripheral-blood monocytes (HPBM) the role of in vitro differentiation on the expression of nonspecific tumoricidal activity, induction of soluble tumor necrosis factor (TNF) activity and TNF-specific mRNA transcription. HPBM were activatable by bacterial lipopolysaccharide (LPS; 1 microgram/ml) for nonspecific cytotoxicity to A375M (human malignant melanoma cell line) only during the first 24 h of in vitro differentiation. Activated supernatants of HPBM were found to be partially neutralizable (75 +/- 7%) by rabbit polyclonal anti-TNF antibody and, in freshly isolated HPBM, the release of soluble TNF activity determined by the L929 assay was found to occur only after activation with LPS. Maximal TNF release occurred at 8 h of LPS stimulation, and required both protein and RNA synthesis as evidenced by the ability of both actinomycin D and cycloheximide to inhibit its release. Neither control untreated HPBM nor recombinant interferon-gamma (rIFN-gamma; 1 U/ml)-treated HPBM alone released soluble TNF activity. Further in vitro culture determined that HPBM were activatable for TNF release out to 72 h of culture after which HPBM became resistant to LPS-mediated TNF release. The expression of TNF and c-fos mRNA was also determined during in vitro differentiation. Both TNF and c-fos mRNA were expressed in freshly isolated HPBM, and returned to baseline by 24 h of in vitro culture. Treatment of HPBM with LPS induced TNF transcription as late as 5 days of in vitro culture with maximal induction occurring during the first 48 h. rIFN-gamma significantly induced TNF transcription at 24 h in the absence of soluble TNF activity, but did not increase transcription at later times. The expression of nonspecific cytolytic activity, the release of soluble bioactive TNF and the induction of TNF and c-fos mRNA are regulated in HPBM by differentiation-determined processes.

Cell Differentiation↗
PubMed1990

Effect of retinoids on the release and gene expression of tumor necrosis factor-alpha in human peripheral blood monocytes.

The effect of retinoic acid (RA) and retinol (ROH) on the release of tumor necrosis factor (TNF) by human peripheral blood monocytes (HPBM) was determined. HPBM were cultured for various periods of time in either 5% complete (cAB) or delipidized (DLS) AB serum. TNF release (L929 cytolytic assay) in the presence of cAB occurred during the first 3 days of in vitro culture. Delipidization of AB serum completely inhibited the lipopolysaccharide (LPS)-induced release of TNF by HPBM. Addition of RA (0.5 microM) to DLS restored LPS-induced TNF release by HPBM, and supplementation with ROH (1.0 microM) resulted in release of TNF-like activity, but only after 3 days of in vitro culture. The maintenance of TNF release by the addition of exogenous RA after 3 days of in vitro culture suggested that depletion of endogenous RA was partially responsible for loss of TNF-like activity. The levels of endogenous TNF protein and mRNA were not influenced by delipidization of serum and were found to be similar to those of HPBM cultured in the presence of AB serum. TNF protein and mRNA were undetectable in HPBM ROH-treated cell lysates, although cytolytic activity was observed in culture supernatants. These results suggest that retinoids are required for the release of cytolytic factors from HPBM and that non-TNF cytolytic factors may be released by these cells at different stages of maturation.

Cells, Cultured↗
PubMed1990

Inhibition of lymphokine-activated killer cell generation by blocking factors in sera of patients with head and neck cancer.

Cytolytic activation of peripheral blood lymphocytes by recombinant interleukin-2 (rIL-2) in patients with squamous cell carcinoma (SCC) of the head and neck may be inhibited by serum blocking factors, and this could influence therapeutic efficacy. Peripheral blood lymphocytes from 21 patients with this disease and 17 controls were incubated with 10-1000 U rIL-2 for 6 days in supplemented complete medium (containing 10% fetal calf serum) or the same medium plus 10% autologous serum. After washing the effector cells, we determined their cytotoxicity against K562 and MDA1386, a lymphokine-activated-killer(LAK)-sensitive SCC cell line, using a 51Cr-release assay. Patient sera inhibited LAK-generated lysis of both MDA1386 and K562, while control sera from healthy persons inhibited LAK-generated lysis of MDA1386. The blocking activity of patient sera tended to be greater than that of control sera. The sera of patients with untreated or recurrent disease and those who were free of disease had equivalent inhibitory capacity. The serum blocking factor acted in a dose-dependent manner, and inhibition was overcome by increasing the dose of rIL-2. Levels of circulating immune complexes (measured by the C1q binding method) did not correlate significantly with inhibition. A clinical protocol of repeated plasma exchange in patients with advanced and recurrent squamous cell carcinoma of the head and neck allowed sequential study of one patients's serum before, during, and after treatments. Plasmapheresis removed serum inhibitory factors, albeit temporarily. The activity of serum blocking factors in patients with this disease can be modulated by increasing doses of rIL-2 and by plasma exchange. This modulation may be important to improving clinical response rates for patients undergoing immunotherapy.

Antigen-Antibody Complex↗
PubMed1990

Circulating myeloid progenitor cell kinetics during hematologic recovery from chemotherapy and subsequent recombinant human granulocyte-macrophage colony-stimulating factor administration.

Hematopoietic recovery from chemotherapy may be associated with an increase in circulating myeloid progenitor cell concentration (CFU-GM); these cells may be harvested by apheresis and used for autologous transplantation after high-dose cytoreductive therapy. Not all patients will demonstrate this increase, possibly due to damage to the stem cell compartment from prior chemoradiotherapy. Elevated circulating CFU-GM has also been reported in patients after short-term administration of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF); whether elevation would persist during longer duration is unknown. We measured circulating CFU-GM (by both limiting dilution in liquid culture and colony formation in semisolid media) in patients with sarcoma who began infusion of rhGM-CSF during recovery from chemotherapy. Patients with elevated circulating CFU-GM did not sustain these levels during subsequent rhGM-CSF infusion. By contrast, patients without rebound elevation of circulating CFU-GM following chemotherapy recovery did increase CFU-GM levels with rhGM-CSF administration. The proportion of marrow CFU-GM in cell cycle during chemotherapy recovery was elevated in both patient groups and remained elevated with rhGM-CSF administration. Both marrow and peripheral blood limiting dilution assays demonstrated linear growth kinetics, indicating a direct effect of the in vitro growth factor (also rhGM-CSF) on progenitor cells without excessive influence or dependence on accessory cells in culture. The use of rhGM-CSF to restore circulating CFU-GM for apheresis during recovery in patients lacking such elevation merits further study.

Antineoplastic Agents↗
PubMed1990

High dose cyclophosphamide, BCNU and VP-16 with autologous blood stem cell support for refractory multiple myeloma.

Eleven patients with advanced multiple myeloma refractory to standard doses of alkylating agents and salvage therapy with vincristine, adriamycin and dexamethasone (VAD) were treated with high dose cyclophosphamide, BCNU and VP-16 (CBV) with autologous blood stem cell support. Seven patients had marked marrow plasmacytosis (greater than 30%) and four had extensive pelvic bone disease precluding autologous marrow harvest. Four patients responded with a median remission duration of 7 months. Recovery of granulocytes and platelets occurred promptly in 10 evaluable patients with complete hematologic recovery. Autologous blood stem cells can provide safe and effective support for high dose CBV treatment of myeloma patients with extensive marrow plasmacytosis. The short remissions call for better cytoreductive regimens with consideration for earlier use when the myeloma may be more responsive to therapy.

Blood Transfusion, Autologous↗
PubMed1990

Hematopoiesis in limiting dilution cultures: influence of cytokines on human hematopoietic progenitor cells.

We have modified a limiting dilution liquid culture assay, used to quantify hematopoietic progenitor frequency, to simultaneously assess cellular proliferation and differentiation. The frequency of colonies from cord blood obtained with recombinant human interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in combination was comparable to cultures with IL-3 alone. However, IL-3 and GM-CSF in combination were synergistic for higher granulocyte proliferation than IL-3 alone, indicating that enhanced granulocyte production occurred via action of GM-CSF on progenitor cell populations already stimulated into proliferation by IL-3. Peak proliferation was evident at 4 weeks in culture, with metamyelocytes predominating; at 6 weeks, mostly neutrophils and eosinophils were present, and eosinophils were more numerous in cultures with IL-3. Increasing concentrations of erythropoietin (epo) in liquid culture with IL-3 or GM-CSF decreased absolute granulocyte yield while stimulating erythroid proliferation. The influence of epo on lineage morphology for cells plated in methylcellulose was markedly less evident by comparison, arguing against an inductive effect of epo to shift progenitor cell lineage. This liquid culture methodology may be a useful tool for preclinical screening of cytokines on human hematopoietic progenitor cells.

Cell Count↗
PubMed1989

Arachidonic acid metabolites produced by platelet-depleted human blood monocytes: a possible role in thrombogenesis.

The arachidonic acid metabolites produced by human peripheral blood monocytes were studied to determine which metabolites could have a role in thrombogenesis. Monocytes were found to be free of platelets by scanning electron microscopy and by measurement of 12-HETE. Human peripheral blood monocytes produce thromboxane as their major metabolite. Thromboxane levels reached a plateau at 12-16 hours of culture. Monocytes produced relatively little prostaglandin E2 or F2. In contrast to our control platelet preparation, neither A23187 (1-10 microM) nor exogenous arachidonic acid (0-40 microM) caused an increase in monocyte thromboxane B2. On the other hand, lipopolysaccharide (20 micrograms per ml), collagen (2.5 mg per 10(7) cells), and thrombin (5-10 units per ml) caused a two- to fivefold increase in monocyte thromboxane B2 in most donors but had no effect on prostaglandin F1 alpha levels. Blockage of thromboxane synthase by 1-benzylimidazole abolished thromboxane B2 production but did not increase prostaglandin F1 alpha. Finally, aspirin-treated platelets from a volunteer donor, which were refractory to 30 microM arachidonate, could be aggregated by isolated blood monocytes. Our data indicate that monocytes are capable of producing thromboxane in large amounts. The regulation of this increase, however, appears to be quite different from platelets. We postulate that monocytes may have a role in hemostasis by virtue of their ability to adhere at sites of vascular injury and release thromboxane, which may enhance platelet aggregation and thrombus formation.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1989

Analysis of peripheral blood granulocyte-macrophage colony growth by limiting dilution assay.

Analysis of myeloid progenitor cells in the peripheral blood (peripheral blood colony-forming unit granulocyte-macrophage; PBCFU-GM) is limited by their low frequency and by the presence of inhibitory cell populations. These factors limit the study of cytokines and cellular influences on PBCFU-GM in semisolid media assays and complicate the interpretation of data. We have developed a limiting dilution assay (LDA) in liquid culture for PBCFU-GM that allows evaluation of inhibitory or accessory effects of other cell populations and estimation of progenitor cell frequency. Using this system we have examined the inhibitory effect of autologous monocytes on in vitro colony growth. After monocyte depletion by counterflow centrifugal elutriation and adherence, colony growth with recombinant human granulocyte-macrophage colony-stimulating factor was linear over a wide range of cell densities, indicating a direct proliferative effect on circulating myeloid progenitor cells. Simultaneous PBCFU-GM assays in agar demonstrated monocyte inhibition but did not afford reliable interpretation of either progenitor frequency or linear growth kinetics in a statistically verifiable fashion. LDA in liquid culture may be a useful tool to study the effects of various cytokines and cell populations on PBCFU-GM in vitro and in vivo.

Colony-Forming Units Assay↗
PubMed1989

Analysis of risk factors for fatal hemorrhage during induction therapy of patients with acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL), an uncommon subtype of acute myelogenous leukemia (AML), has a high incidence of early hemorrhagic death during induction therapy; however, patients with APL surviving induction and obtaining complete remission have a good prognosis, with a longer remission duration than other subtypes of AML. We sought to determine if changes in selected clinical and laboratory coagulation parameters during induction therapy were significantly associated with fatal hemorrhage in that week, or were predictive of fatal hemorrhage in the following week. The first six weeks of induction therapy were studied in 65 patients, during which time 23 patients (35%) died from hemorrhagic complications. Time intervals analyzed were week 1, week 2, weeks 3 and 4, and weeks 5 and 6. There was no significant difference in the prevalence of severe hypofibrinogenemia (less than 150 mg%), prolongation of the prothrombin time (greater than 14 s), or presence of infection between patients who sustained fatal hemorrhage versus those who did not, for any given time period. The most significant parameter was the inability to obtain a posttransfusion platelet count of over 40,000/microliters in at least one half of the platelet transfusions administered in that week (p less than 0.001). This last parameter was the only variable that was also significantly associated with an increased risk of fatal hemorrhage for the following week (p less than 0.005). Clinical trials investigating management of coagulopathy in APL should evaluate the effect of therapy on response to platelet transfusion as well as on other laboratory parameters.

Adolescent↗
PubMed1988

Acute myeloblastic leukemia with hyperleukocytosis: risk factors for early mortality in induction.

Eighty-five patients with acute myeloblastic leukemia (AML) presenting with hyperleukocytosis (HL) were analyzed to assess morbidity and mortality in early induction. Patients who failed to achieve remission were older and more often had pulmonary leukostasis (62% vs 23%, p = .01) and hepatomegaly (54% vs 31%, p = .06) at presentation. Thirty-seven patients (44%) did not achieve complete remission (CR); 17 (54%) died early in induction therapy, 11 directly as a result of pulmonary hemorrhage with respiratory failure, while 5 had both pulmonary hemorrhage with respiratory failure and CNS hemorrhage. Early death patients were older and more often had pulmonary leukostasis (88% vs 29%, p less than .0001), hepatomegaly (71% vs 34%, p = .01), hyperbilirubinemia (60% vs 16%, p = .01) and hypofibrinogenemia (47% vs 12%, p less than .01) at presentation. Primarily for technical reasons, preinduction leukapheresis was not employed as often in this very-high-risk group as in other patients (56% vs 82%, respectively). Thus, sufficient heterogeneity exists in patients presenting with HL to define a subset of patients at particularly high risk for early mortality. Preinduction leukapheresis applied in a prospective controlled fashion should be evaluated to assess if such treatment may decrease early mortality in this group.

Adolescent↗
PubMed1988

TGF-beta inhibits the in vitro induction of lymphokine-activated killing activity.

Employing serum-free media, human peripheral blood mononuclear cells, and purified recombinant interleukin-2 (IL-2), conditions were observed in which the development of IL-2-driven cytotoxic activity was suppressed. The cytotoxic activity of such IL-2-generated lymphokine activated killing (LAK) was tested against natural killer-resistant cultured tumor cells (Daudi, Raji, and a glioma). LAK generation was inhibited by addition of some normal sera, normal platelets, or some tumor cells. Because recent reports have indicated that transforming growth factor-beta (TGF-beta)-like factors are often secreted by tumors and the acidic alpha granules of platelets and can be present in sera, we tested the effect of purified human TGF-beta on the activation of LAK. Our results indicated that TGF-beta is very suppressive for LAK induction, and can completely prevent both the IL-2-driven proliferation and cytotoxicity at concentrations as low as 5 ng/ml. Titrations of IL-2 and of TGF-beta indicated that the suppression is dose-dependent and can be avoided by employing higher levels of IL-2. It was also found that the suppressive effect of TGF-beta can be overcome by washing suppressed cell populations and further culture in low levels of IL-2. Collectively, these data indicate that TGF-beta can be a potent inhibitor of LAK generation under standard activation conditions, but that this effect is regulated by the relative level of IL-2 and may be overcome and/or reversed in vitro.

Blood Platelets↗
PubMed1988

Optimization of platelet concentrate collection for continuous flow cell separation devices (CFCS).

The ability to collect and transfuse a known quantity of platelets to a thrombocytopenic patient, which would assure hemostasis, requires that the quantity needed for transfusion is known, and that the quantity can be predictably collected from the donor. Collection of single donor platelet concentrates (SDPC) by continuous flow cell separation (CFCS) was introduced some ten years ago, but the variables that contribute to the yield have not been integrated into any mathematical model that could be implemented by the device to produce predictable yields, and automation alone has been insufficient to result in predictability. Three major factors contribute to platelet yield: the biologic contribution of the donor; procedure collection parameters, and the efficiency of the device. Data collected from Spectra, COBE 2997 and CS 3000 SDPC procedures suggested that the 35 x 10(11) average yield of PC represented 20-35% of the total quantity (TQ) available in the intravascular space of the donor. The percent collected from individual multiply pheresed donors, however, was consistent over multiple procedures. The volume of blood processed (a procedure variable) is also some percent of the blood volume (BV) of the donor. When these two variables (% TQ and % BV) were combined and statistical correlations to the yield examined, there were sufficiently consistent relationships between the two to mathematically model equations that predict reasonably well the yield on any of the CFCS devices. A light monitoring device attached to the Spectra translates changes in light transmission to platelet concentration in the collect line, and electronically tracks the accumulating yield throughout the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Component Removal↗
PubMed1986

Identification of a human monocyte cytotoxicity-inducing factor from T cell hybridomas produced from Sezary's cells.

Sezary's syndrome is a leukemic proliferation of OKT4+ lymphocytes. Sezary cells were isolated by differential centrifugation and fused to CEM.8azar.C, and HGPRTase-lacking clone of CEM. The hybrid cells were studied for their ability to produce soluble mediators of human monocyte cytotoxicity. The product of a single clone, FtF3, which bore the surface phenotype of Sezary cells, was characterized. Monocyte cytotoxicity-inducing factor (MCF) was found to be stable at pH 2 for 1 hr, unlike IFN-gamma, and was found to be more heat stable as well. Moreover, treatment of MCF with antisera to IFN-gamma, IFN-alpha or a combination of IFN-gamma and IFN-alpha failed to neutralize its biologic activity. MCF binds to matrix gel Red A. MCF eluted from this dye-ligand was found to have an apparent m.w. of 11,500 by gel filtration and 14,700 by SDS-polyacrylamide gel electrophoresis. MCF produced by hybridized Sezary cells appear to be neither IFN-gamma nor an altered molecular form of IFN-gamma, yet is a potent inducer of human monocyte cytotoxicity.

Animals↗
PubMed1986

Centrifugal elutriation as a method for isolation of large numbers of functionally intact human peripheral blood monocytes.

Centrifugal elutriation was used further to isolate human peripheral blood monocytes (HPBM) from mononuclear-enriched cells harvested as a secondary component following platelet concentration collection samples. HPBM were recovered in either one or two populations consisting of either total HPBM or small (SM) and large monocytes (LM). The elutriation was carried out at 3,500 +/- 5 rpm for the separation of lymphocytes and HPBM in Ca++- and Mg++-free PBS without EDTA. An average of 5.05 +/- 1.50 X 10(8) HPBM were recovered in the total HPBM with a purity of 95% +/- 3%. The SM and LM were obtained by splitting the total HPBM into two equal populations with an HPBM purity of 92% +/- 3% and 93% +/- 3, respectively, by nonspecific esterase staining. The elutriation media were shown to have no effect on viability by trypan blue exclusion. All three HPBM populations were shown to be histochemically (lack of reactivity to leu-1 and leu-7) and functionally (depletion of NK cell activity) purified from the lymphocyte population. The HPBM populations were enriched in HLA-Dr, OKM-1, OKM-5, MY-8, and leu M-3 monoclonal antibody marker staining. There were no differences in percent positive cells between SM and LM populations for any of the monocyte-specific monoclonal antibodies. All three monocyte populations mediated antibody-dependent cell-mediated cytotoxicity to human red blood cells, with LM mediating more lysis (27.0% +/- 5%) than SM (7% +/- 3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗