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Biomedical subjects

J S Abrams

Publications and source records attributed to J S Abrams.

At least 91 records · Page 5Linked to original sources
PubMed1991

A phase I/II study of high-dose megestrol acetate in the treatment of metastatic breast cancer.

A dose-response relationship has been suggested for medroxyprogesterone acetate in the treatment of advanced breast cancer. To determine the tolerability and efficacy of increasing doses of megestrol acetate in the treatment of metastatic breast cancer, we conducted a phase I/II study among 57 patients. Three patients each received 480, 800, and 1280 mg/d; 48 patients received 1600 mg/d. Of the 57 patients, 56 patients had had disease progression on prior hormone therapy, chemotherapy, or both. Twenty-seven patients had previously received standard-dose MA (160 mg/d). Among the 37 patients with measurable disease, high-dose megestrol acetate (HDMA) produced 6 (16%) complete responses (CRs) and 6 (16%) partial responses (PRs); 11 patients achieved stable disease (SD). HDMA resulted in improvement or stabilization in 12 of the 20 patients with evaluable, non-measurable disease. There were no responses among the 6 patients with liver metastases. Among the 27 patients who were previously treated with standard-dose MA, including 9 patients with primary treatment failure, HDMA resulted in 1 CR, 3 PRs, and 10 SD. Toxicities, which were mild and reversible, included fluid retention, hypertension, hyperglycemia, and mild congestive heart failure. Two patients had superficial phlebitis. The most profound side effect was weight gain which occurred in 43 patients (75%). This study suggests a dose-response relationship for MA in the treatment of advanced breast cancer. A randomized trial to determine the optimal dose is ongoing.

Adult↗
PubMed1991

Augmentation of granulocyte/macrophage colony-stimulating factor expression by ultraviolet irradiation is mediated by interleukin 1 in Pam 212 keratinocytes.

Keratinocytes are a potent source of a variety of cytokines including granulocyte-macrophage colony-stimulating factor (GM-CSF). In this study, we have shown that ultraviolet B (UVB) irradiation augments GM-CSF mRNA expression by murine keratinocytes. This is reflected in the increased production of GM-CSF protein by these cells. In the same cell population, exposure to UVB irradiation increases interleukin 1 alpha (IL-1 alpha) mRNA and IL-1 protein as detected by bioactivity. This increase in IL-1 alpha precedes the increase of GM-CSF mRNA. Addition of recombinant IL-1 alpha to the medium increases GM-CSF mRNA expression. Anti-IL-1 alpha antibodies can completely inhibit UV-augmented GM-CSF mRNA expression. These results demonstrate that UVB irradiation-induced augmentation of GM-CSF is mediated by UV-induced IL-1 alpha.

Animals↗
PubMed1991

Human upper airway epithelial cell-derived granulocyte-macrophage colony-stimulating factor induces histamine-containing cell differentiation of human progenitor cells.

Nasal polyps and allergic rhinitis are upper airway inflammatory conditions characterized by increased numbers of eosinophils and metachromatic cells in the epithelial layer of the nasal mucosa. The objective of the current studies was to investigate the potential contribution of epithelial cells to the accumulation of inflammatory cells in the tissue. We have established pure cultures of human upper airway epithelial cells from normal and inflamed nasal polyps and allergic rhinitis tissue and examined the ability of conditioned medium from these cells (EpCM) to induce differentiation of human hemopoietic progenitors in vitro. We show that, under appropriate culture conditions, EpCMs, particularly those from cells derived from inflamed tissues, induce histamine-containing cell differentiation of cells of the human HL-60 myeloid leukemia cell line. These EpCMs also induce the emergence of both eosinophil/basophil and granulocyte/macrophage colonies in methylcellulose cultures of human peripheral blood mononuclear cells. We also show that CMs from epithelial cells derived from inflamed tissues contain greater amounts of granulocyte-macrophage colony-stimulating factor (GM-CSF) compared to CMs from normal epithelial cells. Finally, we show that the histamine-containing cell differentiation of HL-60 cells as well as the colony growth induced by EpCM can be fully inhibited by preincubating this CM with a monoclonal neutralizing antibody to human GM-CSF. These studies: (a) illustrate the ability of human upper airway epithelial cells to secrete GM-CSF in vitro; (b) demonstrate differences between normal and inflamed tissue-derived epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1991

Immediate and late airway response of allergic rhinitis patients to segmental antigen challenge. Characterization of eosinophil and mast cell mediators.

Segmental antigen bronchoprovocation was used to define the nature of the inflammatory process in allergic airway disease. Bronchoalveolar lavage fluid obtained from allergic rhinitis patients 12 min after segmental antigen instillation (immediate response) revealed a significant increase in histamine and tryptase, but no cellular response. Repeat segmental lavage 48 h later (late response) showed marked and significant increases in both low and normal density eosinophils as well as striking elevations of eosinophil granular protein levels (major basic protein, eosinophil-derived neurotoxin, eosinophil cationic protein, and eosinophil peroxidase). Leukotriene C4, but not tryptase, concentrations were also consistently elevated in late lavage samples. Further, the late lavage samples showed a significant increase in interleukin-5 concentrations that correlated with the presence of eosinophils and eosinophil granular proteins. Neither eosinophils nor soluble mediators of eosinophils increased when normal subjects were similarly challenged with antigen. These data suggest that eosinophils are attracted to the airway during the late-phase allergic reaction and that IL-5 may produce changes in airway eosinophil density and promote the release of granular proteins to cause airway injury.

Adult↗
PubMed1991

Neutrophilic differentiation induced by human upper airway fibroblast-derived granulocyte/macrophage colony-stimulating factor (GM-CSF).

We have established primary lines of fibroblasts from nasal polyp (NP) tissues as well as from normal nasal (NN) mucosa and have examined the ability of these cells to release hormone-like peptide messenger molecules (cytokines). Our results show that human upper airway fibroblasts release granulocyte/macrophage colony-stimulating factor (GM-CSF), granulocyte-CSF (G-CSF), and macrophage-CSF (M-CSF) in vitro. We also show that fibroblasts derived from NP tissue express the gene for GM-CSF at a higher level, and release the GM-CSF product in greater amounts, than NN fibroblasts. In addition, we have examined the ability of these fibroblasts and their conditioned medium (CM) to induce differentiation of human hemopoietic progenitor cells. After 7 d, cultures of these cells in RPMI-10% fetal bovine serum contained 5 +/- 2.5% (mean +/- SD) neutrophils. In contrast, culture of progenitor cells with fibroblasts resulted in significantly greater neutrophilic differentiation (18 +/- 4%). Culture in fibroblast-CM induced a similar degree of differentiation, and fibroblast-CM from NP fibroblasts elicited greater differentiation compared to CM from NN fibroblasts (17.5 +/- 3 versus 12 +/- 3%). The neutrophilic differentiation induced by fibroblast-CM can be fully inhibited by preincubating this CM with a monoclonal neutralizing antibody to human GM-CSF. Thus, our results demonstrate: (1) the ability of human upper airway fibroblasts to release GM-, G-, and M-CSF in vitro; (2) that fibroblasts derived from NP tissues express the gene and release the product GM-CSF at greater levels compared to NN fibroblasts; and (3) that fibroblast-derived GM-CSF causes neutrophilic differentiation of human hemopoietic progenitors.

Animals↗
PubMed1991

Interleukin-5 and the posttreatment eosinophilia in patients with onchocerciasis.

To understand the role of the eosinophilopoietic cytokine IL-5 in humans, the posttreatment eosinophilic response in a group of microfilaria (mf)-positive patients with onchocerciasis (n = 10) was examined before and after treatment with diethylcarbamazine (6 mg/kg for 7 d). Sequential blood samples were assessed at 24 and 1 h before treatment (baseline values), then at frequent intervals over the next 14 d. Symptom scores, skin microfilariae (mf), and peripheral blood eosinophil counts were recorded as a function of time after treatment, and serum levels of IL-5 were quantitated by a highly sensitive (sensitivity greater than or equal to 20 pg/ml) monoclonal-based ELISA. Pretreatment eosinophil counts ranged from 240 to 1,186 eosinophils/microliter (geometric mean, 675), and the mf counts from 10 to 218 per mg skin (geometric mean, 79). After an initial decline in the peripheral eosinophil count to 28 +/- 8% of pretreatment levels at 8 h after beginning treatment, the eosinophil counts steadily increased over the next 2 wk, reaching a maximum at 14 d (257 +/- 38% of pretreatment levels). Serum levels of IL-5 rose sharply from pretreatment levels to a peak of 70.5 +/- 11 pg/ml by 24 h after treatment. Serum IL-5 remained elevated over the next 2-3 d and declined toward baseline by approximately 6 d after treatment, at which time the eosinophil levels were steadily increasing. IL-3 and granulocyte macrophage colony-stimulating factor, two other cytokines implicated in eosinophilopoeisis, were not detectable in the serum at any time before or after treatment. The rise in serum IL-5 before the posttreatment eosinophilia seen in this group of patients with onchocerciasis demonstrates a temporal relationship between IL-5 and the subsequent development of eosinophilia and implicates IL-5 as an important mediator of eosinophilia in humans.

Adolescent↗
PubMed1991

Antisense RNA inhibition of hematopoietic growth factor production.

Vectors that generate antisense RNA targeted to granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA sequences were constructed using a strong viral promoter and a T cell-specific control element from the human CD2 gene. Stably transfected lymphoid clones expressing antisense RNA were tested for their ability to synthesize GM-CSF in response to stimulation with phorbol 12-myristate 13-acetate (TPA) and ionomycin. At early time points (4 and 8 hr) following stimulation, mean GM-CSF production by clones expressing antisense RNA was 10% the mean of control clones (p less than 0.001). Analysis of mean log data for 15 antisense clones demonstrated that GM-CSF production remained depressed at 12 and 24 hr time points, averaging 37% of that of the control clones (p less than 0.01). We conclude that antisense inhibition of growth factor production may be an effective strategy to investigate the role of specific growth factors in hematopoiesis in vivo in transgenic mice.

Animals↗
PubMed1991

Special shoulder problems in the throwing athlete: pathology, diagnosis, and nonoperative management.

Shoulder problems in the overhead and throwing athlete can result in rotator cuff tendinitis. Biomechanically, there is a delicate balance between mobility and stability of the shoulder complex. Repetitive overhead stressful motion can lead to overuse tendinitis, subtle instability, labral changes, and eventual fiber failure of the rotator cuff. Secondary impingement symptoms are commonly present. An accurate diagnosis along with an early and aggressive rehabilitation program is essential in the treatment of these athletes.

Athletic Injuries↗
PubMed1990

Anti-IL-6 monoclonal antibodies protect against lethal Escherichia coli infection and lethal tumor necrosis factor-alpha challenge in mice.

Potentially fatal physiologic and metabolic derangements can occur in response to bacterial infection in animals and man. Recently it has been shown that alterations in the levels of circulating cytokines such as IL-6 and TNF-alpha occur shortly after bacterial challenge. To understand better the role of IL-6 in inflammation, we investigated the effects of in vivo anti-mouse IL-6 antibody treatment in a mouse model of septic shock. Rat anti-mouse IL-6 neutralizing mAb was produced from splenocytes of an animal immunized with mouse rIL-6. This mAb, MP5-20F3, was a very potent and specific antagonist of mouse IL-6 in vitro bioactivity, demonstrated using the NFS60 myelomonocytic and KD83 plasmacytoma target cell lines, and also immunoprecipitated radiolabeled IL-6. Anti-IL-6 mAb pretreatment of mice subsequently challenged with lethal doses of i.p. Escherichia coli or i.v. TNF-alpha protected mice from death caused by these treatments. Pretreatment of E. coli-challenged mice with anti-IL-6 led to an increase in serum TNF bioactivity, in comparison to isotype control antibody, implicating IL-6 as a negative modulator of TNF in vivo. Anti-TNF-alpha treatment of mice challenged i.p. with live E. coli resulted in a 70% decrease in serum IL-6 levels, determined by immunoenzymetric assay, compared to control antibody, thereby supporting a role for TNF-alpha as a positive regulator of IL-6 levels. We conclude that IL-6 is a mediator in lethal E. coli infection, and suggest that antagonists of IL-6 may be beneficial therapeutically in life-threatening bacterial infection.

Acute-Phase Reaction↗
PubMed1990

High-dose recombinant interleukin-2 alone: a regimen with limited activity in the treatment of advanced renal cell carcinoma.

Sixteen patients with metastatic renal cell carcinoma were treated with high-dose bolus recombinant interleukin-2 (rIL-2) alone at a dose and schedule identical to those that produced a 35% response rate among 72 patients in a trial reported by the Surgery Branch, National Cancer Institute (NCI), Bethesda, Md, in which rIL-2 plus lymphokine-activated killer (LAK) cells was used for the treatment of renal cell carcinoma. Patients received two 5-day cycles of 100,000 Cetus U/kg (600,000 IU/kg) of rIL-2 infused intravenously over 15 minutes every 8 hours; each treatment cycle was separated by 1 week. No objective responses were seen. The toxicity of rIL-2 given alone at these high doses was similar to that noted with high-dose rIL-2-LAK cell therapy. The lack of responses seen in this trial also differed from the 21% response rate observed by the NCI Surgery Branch, using rIL-2 alone at an identical schedule and dose in 56 patients with renal cell carcinoma. Only minor differences in such recognized prognostic variables as performance status, tumor burden, and rIL-2 dose intensity were noted between this study and other trials reported by the NCI Surgery Branch and by the IL-2-LAK Working Group. Our analysis indicates that, because of the smaller number of patients in our trial, not enough subjects were included with the ideal characteristics to attain the 21% response rate seen in the NCI study. However, the precise nature of these characteristics remains unclear.

Adult↗
PubMed1990

Regulation of parasite-induced eosinophilia: selectively increased interleukin 5 production in helminth-infected patients.

Production of the eosinophilogenic cytokines interleukin 3 (IL-3), granulocyte/macrophage colony-stimulating factor (GM-CSF), and IL-5 by mitogen-stimulated peripheral blood mononuclear cells was compared between 11 noneosinophilic individuals and seven patients with helminth-induced eosinophilia. Both the kinetics and quantities of IL-3 and GM-CSF were similar in the two groups. In contrast, IL-5 production at both the protein and the mRNA level was markedly greater in the eosinophilic patients, an observation suggesting that IL-5 may be particularly important in mediating the selective eosinophilia seen in filarial and other helminth infections.

Adult↗
PubMed1990

Regulation of immunoglobulin (Ig)E synthesis in the hyper-IgE syndrome.

The hyper-IgE (HIE) syndrome is characterized by high IgE serum levels, chronic dermatitis, and recurrent infections. The mechanisms responsible for hyperproduction of IgE in HIE patients are presently unknown. We investigated whether spontaneous in vitro IgE synthesis by PBMC from seven HIE patients was sensitive to signals (cell adhesion, T/B cell cognate interaction and lymphokines: IL-4, IL-6, and IFN-gamma) known to regulate IgE induction in normals. Our results show that, unlike IL-4 dependent IgE synthesis induced in normals, spontaneous IgE production by PBMC from HIE patients was not blocked by monoclonal antibodies to CD2, CD4, CD3, and MHC class II antigens. Furthermore, antibodies to IL-4 and IL-6 did not significantly suppress IgE production. IFN-gamma had no significant effects on spontaneous in vitro IgE synthesis. To test whether an imbalance in lymphokine production might underlie hyperproduction of IgE in HIE patients, mitogen-induced secretion of IL-4 and IFN-gamma by PBMC was assessed. No significant difference was detected between HIE patients and normal controls. Thus, ongoing IgE synthesis in the HIE syndrome is largely independent of cell-cell interactions and endogenous lymphokines, and is due to a terminally differentiated B cell population, no longer sensitive to regulatory signals.

Adult↗
PubMed1990

Interleukin-2 therapy in patients with metastatic malignant melanoma: a phase II study.

Forty-seven patients with metastatic malignant melanoma were treated with two 5-day cycles of 100,000 U/kg recombinant interleukin-2 (IL-2) intravenously (IV) every 4 hours separated by 1 week. This dose and schedule of IL-2 were identical to those used in a previous combined IL-2 and lymphokine-activated killer (LAK) cell phase II clinical trial of the IL-2/LAK Working Group. Patient eligibility criteria, and clinical management guidelines were similar to those used in the previous trial. Forty-six patients were assessable for response. Objective responses were observed in 10 of 46 patients (two complete responses [CRs], eight partial responses [PRs]) or 22% with responses occurring in lung and liver as well as lymph nodes and subcutaneous sites. The median response duration was 8 months. Toxicity was significant; three patients developed myocardial infarction, and one patient died during therapy. Overall the toxicity and response rate for single-agent IL-2 are similar to that observed with IL-2 administered in combination with LAK cells in the previous trial. These results suggest that single-agent therapy with IL-2 when administered in this schedule has significant antimelanoma activity in humans, and that LAK cells generated from peripheral blood add little to the antimelanoma activity of this dose and schedule of IL-2.

Adult↗
PubMed1990

Current status of high-dose progestins in breast cancer.

Progestins at standard doses have compared favorably with tamoxifen for the front-line treatment of women with metastatic breast cancer. Attempts to further enhance the role of progestins have centered on dosage escalation, based on European data suggesting a dose-response effect. A phase I/II pilot trial at the University of Maryland demonstrated that doses of megestrol acetate up to 1,600 mg/d were well tolerated for prolonged periods. Responses were seen in patients whose disease was refractory to both standard doses of megestrol acetate and to tamoxifen. Different mechanisms of progestin action on breast tumors are theorized at the higher doses, which could account for the dose-response effect. Two large multi-institutional dose comparison trials of megestrol acetate in metastatic breast cancer have been undertaken in the United States. The Piedmont Oncology Association recently reported a significant benefit for megestrol acetate 800 mg/d compared with the standard 160 mg/d in terms of response and disease-free and overall survival. The largest trial is currently ongoing in the Cancer and Leukemia Group B. They are comparing 800 and 1,600 mg/d with standard doses, and results from this study are eagerly anticipated.

Antineoplastic Agents↗
PubMed1989

Induction of human IgE synthesis by CD4+ T cell clones. Requirement for interleukin 4 and low molecular weight B cell growth factor.

We have analyzed in detail the precise requirements for the induction of human IgE synthesis using several experimental approaches with purified B cells and well-characterized alloantigen-specific CD4+ T cell clones expressing different profiles of lymphokine secretion. Using these clones under cognate conditions in which the B cells expressed alloantigens recognized by the cloned T cells, we have confirmed that IL-4 is required for the induction of IgE synthesis, but we have clearly demonstrated that IL-4 by itself is not sufficient. With several cloned CD4+ T cell lines, including an IL-4-producing clone that could not induce IgE synthesis, and cloned T cells pretreated with cyclosporin A to inhibit lymphokine synthesis, we showed that Th cell-B cell interactions are necessary for IgE synthesis, and that low molecular weight B cell growth factor (LMW-BCGF) and IL-4, in combination, are lymphokines of major importance in the induction of IgE synthesis. Together our results indicate that optimal induction of an IgE-specific response requires the exposure of B cells to a particular complex of signals that include (a) a signal(s) involving Th-B cell interaction that primes B cells to receive additional signals from soluble lymphokines, (b) a specific B cell proliferative signal provided by LMW-BCGF, and (c) a specific B cell differentiation signal provided by IL-4.

CD4-Positive T-Lymphocytes↗
PubMed1989

COOH-terminal-modified interleukin-3 is retained intracellularly and stimulates autocrine growth.

Autocrine growth due to dysregulated growth factor production may have a role in the development of neoplasia. Whether autocrine growth is stimulated by growth factor secretion in an autocrine loop or by intracellular binding of the growth factor to a receptor has been unclear. The carboxyl-terminus coding sequence for murine interleukin-3 (IL-3) was extended with an oligonucleotide encoding a four-amino acid endoplasmic reticulum retention signal. IL-3-dependent hematopoietic cells became growth factor-independent when the modified IL-3 gene was introduced by retroviral gene transfer, despite lack of secretion of the modified IL-3. Hence autocrine growth can occur as a result of the intracellular action of a growth factor and this mechanism may be important in neoplastic and normal cells.

Animals↗
PubMed1989

A limited sampling strategy for cyclophosphamide pharmacokinetics.

A limited sampling strategy was developed to estimate the total area under the curve of plasma cyclophosphamide concentrations versus time (AUC). The strategy was developed with a training set consisting of 29 pharmacokinetic studies in 16 patients who received 1-h i.v. infusions of cyclophosphamide at a dosage of 1000 mg/m2. The strategy was developed by applying stepwise forward multiple regression analysis to cyclophosphamide concentrations observed at each time in the training set (independent variables) versus the AUC (dependent variable). It was confirmed by applying stepwise backward elimination regression analysis to the same data set. The final sampling strategy, which utilized three time points, was: AUC = 40.18C24 + 8.79C4 + 0.83C1 - 28 (dosage/1000), where C24, C4, and C1 represent plasma cyclophosphamide concentrations at 24, 4, and 1 h, respectively, and the dosage is in mg/m2 (r = 0.98). The strategy was validated prospectively with a test data set consisting of 14 pharmacokinetic studies in 11 patients who received 1-h i.v. infusions of cyclophosphamide at dosages of 300, 600, or 1200 mg/m2. The strategy proved highly predictive, with correlation coefficient between predicted and actual AUC of 0.94. The strategy also proved unbiased, with mean percentage of error (+/- SE) of 3.3 +/- 3.6%, and precise, with mean absolute percentage of error of 9.3 +/- 2.7%. The sampling strategy developed is being used in a multiinstitution trial of cyclophosphamide in an effort to relate cyclophosphamide pharmacokinetics, as expressed by AUC, with the toxic or therapeutic pharmacodynamic responses of the drug.

Cyclophosphamide↗