Biomedical subjects

R E Wilson

Publications and source records attributed to R E Wilson.

At least 55 records · Page 3Linked to original sources

PubMed1989

Effect of timing of lymphokine presentation on generation of cytotoxic T lymphocytes.

Encouraging results of clinical trials with interleukin 2 therapy for advanced malignant neoplasms have led to efforts to reduce the toxicity and improve the efficacy of tumor immunotherapy. To begin to achieve this goal, we studied the lymphokine requirements for in vitro generation of polyclonal cytotoxic T lymphocytes (CTL) from C57BL/6 murine thymocytes. We found that both interleukin 2 and interleukin 6 are required for optimal generation of CTL from murine thymocytes. Timing studies show that neither lymphokine alone in culture will produce maximum CTL levels during the first 84 hours of culture. In addition, we found that thymocytes cultured with concanavalin A are unresponsive unless either interleukin 2 or interleukin 6 is present from the onset of culture.

Animals↗

PubMed1989

Ibuprofen causes reduced toxic effects of interleukin 2 administration in patients with metastatic cancer.

Metastatic cancer was treated with interleukin 2 and lymphokine-activated killer cells with the addition of the cyclooxygenase inhibitor ibuprofen in an attempt to reduce side effects in 13 patients (eight male and five female). Twenty-six patients treated with only interleukin 2 and lymphokine-activated killer cells formed the control group. After interleukin 2 administration, a significantly increased number of lymphokine-activated killer cells were transfused in ibuprofen-treated patients. Cytotoxic effects were not significantly different in the treated and untreated groups. With regard to cell phenotype, both groups of patients manifested significant activation of the immune system as measured by T10 and OK1a. Symptom scores were dramatically reduced in patients treated with ibuprofen. Temperature above 37 degrees C were rare. Ibuprofen did not significantly alter rate of response in this immunotherapy trial (38% vs 42%). Ibuprofen is now routinely used in all of our current immunotherapy trials.

Cells, Cultured↗

PubMed1989

Non-clastogenicity in mouse bone marrow of fructose/lysine and other sugar/amino acid browning products with in vitro genotoxicity.

Heated sugar/amino acid reaction mixtures, known to contain products that are clastogenic and/or mutagenic to cells in vitro, were evaluated for clastogenic activity in mouse bone marrow using the erythrocyte micronucleus assay. Heated (i.e. browned) fructose/lysine reaction mixtures were also evaluated in the Salmonella his-reversion assay and the Chinese hamster ovary (CHO) cell chromosomal aberration assay to confirm and extend previous in vitro observations. Significant mutagenicity of fructose/lysine mixtures was observed in Salmonella typhimurium strains TA100, TA2637, TA98 and TA102, with greater activity in mixtures heated at pH 10 than at pH 7. S-9 decreased the activity in strains TA100, TA2637 and TA98, but increased the activity in strain TA102. Both pH 7 and pH 10 reaction mixtures of the fructose/lysine browning reaction were highly clastogenic in CHO cells. Heated mixtures of fructose and lysine, and of glucose or ribose with lysine, histidine, tryptophan or cysteine, did not increase the frequency of micronucleated erythrocytes in mice when administered by the oral route. This indicates the absence of chromosomal aberrations in erythrocyte precursor cells, and indicates that the genotoxic components of the browned mixtures are not absorbed and distributed to bone marrow cells in amounts sufficient to induce micronuclei when given orally. Because sugar/amino acid browning reactions occur commonly in heated foods, it is important to evaluate further the in vivo genotoxicity of browning products in cell populations other than bone marrow.

Animals↗

PubMed1989

Enhanced synthesis of specific proteins, RNA, and DNA caused by hypoxia and reoxygenation.

When Chinese Hamster ovary cells were exposed to severe hypoxia they responded with an enhanced synthesis rate of a small group of specific proteins, which we have termed the oxygen regulated proteins (ORPs). The five major ORPs had molecular weights of 33, 80, 100, 150, and 260 kD. ORP260 was the first ORP to be synthesized at enhanced rates after the induction of hypoxia, reaching its maximal synthesis rate after only a few hours. The other ORPs responded slower, but were being synthesized at maximal rates by 8 hr of hypoxia. Upon reoxygenation, the synthesis rates of the ORPs declined rapidly with ORP260 again responding most rapidly. They all reached control levels by 12 hr of recovery. The induction of enhanced synthesis of these proteins required a very severe degree of hypoxia. They were not seen at oxygen levels higher than 0.03%. While enhanced synthesis of the ORPs was turned on and off quickly with induction of, and recovery from hypoxia, the proteins were not degraded at high rates once synthesized. All five major ORPs have apparent half-lives in excess of 24 hr. When cells were exposed to hypoxia for 20 hr and then allowed to recover for 15 hr, a population of cells was generated that had, on average, at least twice the cell volume as aerobic control cells. These large cells also contained greater than 4C DNA content as well as enhanced amounts of RNA.

Animals↗

PubMed1989

Production of interleukin-6 in vitro parallels development of cytotoxic T lymphocytes from murine thymocytes.

In an attempt to provide information useful for improving tumor immunotherapy, we examined the lymphokine requirements for generation of cytotoxic T lymphocytes (CTL) from C57BL/6 murine thymocytes. Our previous work indicated that interleukin-6 (IL-6) is involved in the maturation of CTL in vitro. Using a standard chromium 51 release assay and P815 mastocytoma tumor cells as targets, we found that after 66 hours of in vitro culture, a much greater CTL response was generated in the presence of interleukin-2 (IL-2) plus IL-6 (70.5% +/- 10.6%) compared with that generated in the presence of IL-2 only (25.2% +/- 1.0%). After 72 hours of culture, however, this difference was no longer significant, with cultures incubated with both IL-2 and IL-6 yielding 70.6% +/- 1.8% lysis versus 64.5% +/- 3.4% for cultures incubated with IL-2 only. To attempt to understand this difference, we examined the production of IL-6 in thymocyte cultures using a cell line, PC-6, that proliferates in the presence of IL-6. We found that the CTL response generated from unfractionated murine thymocytes in the presence of concanavalin A plus IL-2 correlated with production of IL-6 by cells within the thymic population. These data suggest that the generation of a CTL response in the absence of added IL-6 is due to the production of this ubiquitous lymphokine by thymocytes on in vitro culture. We present this as further evidence that IL-6 is necessary for the development of functional CTL from murine thymocytes and may therefore play a role in the development of effective tumor immunotherapy.

Animals↗

PubMed1988

Adoptive immunotherapy of human cancer using low-dose recombinant interleukin 2 and lymphokine-activated killer cells.

The adoptive transfer of recombinant-methionyl human interleukin 2 (rIL-2)-activated autologous peripheral blood mononuclear lymphokine-activated killer (LAK) cells to cancer patients is being evaluated as an alternative to conventional cancer therapy. We have independently developed an alternative regimen to previously reported adoptive immunotherapy protocols using rIL-2 and LAK cells which features the prolonged administration of low-dose rIL-2 (30,000 units/kg) and an automated, entirely enclosed system of peripheral blood cell procurement, culture, harvest, and reinfusion of activated cells. The cell culture system was tested with a murine tumor model in which LAK cells generated in plastic culture bags were reinfused into tumor-bearing mice. Tumor regression was as effective with cells activated in the bags as in conventional culture flasks. Twenty-eight cancer patients were treated for 5 consecutive days with low-dose rIL-2, followed by leukapheresis, infusion of LAK cells, and prolonged IL-2 administration. At least 50% tumor regression was observed in 46% of all patients treated. These data imply that human peripheral blood mononuclear cells retain fully their capacity for rIL-2-induced activation and effector cell function under this alternative approach, and further, that a low-dose rIL-2 regimen with markedly reduced toxicities can be as effective as high-dose rIL-2 regimens if low-dose rIL-2 is given for a prolonged period of time following LAK cell infusion.

Adult↗

PubMed1988

Membrane-bound anti-CD3 monoclonal antibodies trigger cytolytic T-lymphocyte-mediated tumor lysis.

Cytolytic T lymphocytes (CTLs) are an efficient immune mechanism for the destruction of foreign or pathogenic cells. Attempts to use CTLs in human cancer therapy have focused on the cell-surface molecules that regulate CTL function. An important molecule in CTL function is the CD3 antigen. Biochemical characterization has suggested that the CD3 antigen may function as a "trigger" for T-lymphocyte activation. To investigate this possibility, we used monoclonal antibody (MAb) to the CD3 antigen to trigger activation of long-term CTL lines. The anti-CD3 MAb was able to trigger killing of a variety of human and mouse tumor cell lines; however, not all tumor cells were lysed by the CTL. The susceptibility of the tumor cells to CTL-mediated lysis appeared to correlate with the binding of the anti-CD3 MAb to the tumor cell surface. The requirement for surface binding of the MAb was tested by covalently cross-linking the anti-CD3 MAb to the tumor cell membrane. Membrane-bound anti-CD3 MAb triggered high levels of CTL-mediated tumor cell killing. Similar results were obtained when anti-CD3 MAb was cross-linked to phosphatidylethanolamine and inserted into the cell membrane. These results indicate that the attachment of anti-CD3 MAb to the tumor cell surface provides a powerful new approach to the in vitro activation of human killer T cells and the in vivo treatment of human cancer.

Antibodies, Monoclonal↗

PubMed1988

Flavone mutagenicity in Salmonella typhimurium: dependence on the pKM101 plasmid and excision-repair deficiency.

Flavones mutagenic in Salmonella typhimurium fall into two distinct classes, characterized by different structural and metabolic activation requirements and by different strain responses. The mutagenic potencies of a prototype agent of each class, quercetin (3,3',4',5,7-hydroxyflavone) and norwogonin (5,7,8-hydroxyflavone), were determined in tester strains differing in excision-repair capability and in the presence or absence of plasmid pKM101. Two series of strains were used, one with the hisD3052 frameshift mutation and one with the hisG46 missense mutation. With both agents and for both series of strains, the mutagenic response was markedly dependent on the absence of excision repair and the presence of the pKM101 plasmid.

Animals↗

PubMed1988

Polyoma middle T abrogates TPA requirement of murine melanocytes and induces malignant melanoma.

We have transfected the polyoma middle T oncogene into an immortal murine melanocyte cell line, Mel-ab. This highly pigmented line is phorbol ester (TPA) dependent for in vitro growth, suggesting activation and/or down regulation of Protein Kinase C (PKC) is essential for mitogenesis. Moreover, cells of this line do not form tumours when injected subcutaneously into immunocompetent or immunoincompetent mice. Here we show that PyMT alone is sufficient to produce TPA-independence and transformation to the tumourigenic state in transfected Mel-ab cells. Western blot analysis shows that middle T overcomes the TPA requirement by a mechanism independent of PKC down regulation though this does appear to occur when Mel-ab cells are grown continuously in TPA. These results suggest that PyMT is not exerting its transforming effect by PKC down regulation, but conceivably at some later stage of second messenger signalling, possibly through PyMT-c-src protein kinase activity.

Animals↗

PubMed1988

A new regimen of interleukin 2 and lymphokine-activated killer cells. Efficacy without significant toxicity.

Adoptive immunotherapy with high-dose interleukin 2 and lymphokine-activated killer (LAK) cells has proved to be successful in the treatment of some patients with metastatic cancer, but not without a significant degree of associated toxic effects. The primary goal of this study was to substantially reduce the toxicity of this complex and expensive treatment, while maintaining or improving efficacy. To this end, 29 patients were treated with LAK cells in conjunction with a low-dose regimen of interleukin 2 and a prolonged period of administration following LAK cell infusion. This protocol resulted in a considerable reduction in toxicity, as compared with that described in previous studies, without compromising the efficacy. This study offers further confirmation that adoptive immunotherapy of metastatic cancer can be clinically beneficial to patients for whom no other effective therapy is presently available.

Adult↗

PubMed1988

Surgical therapy of localized abdominal non-Hodgkin's lymphomas.

Non-Hodgkin's lymphomas may involve a variety of abdominal organs, including the liver, spleen, gastrointestinal tract, and retroperitoneum. The number of organs potentially involved and the noncontiguous mode of spread make non-Hodgkin's lymphoma a difficult tumor to evaluate at the time of laparotomy. To clarify the surgical management of patients with this tumor, we retrospectively reviewed the medical records of 202 patients with histologically proven abdominal lymphomas. Within this group, 36 patients underwent laparotomy before they had chemotherapy or radiation therapy. Ten patients were explored to establish a histologic diagnosis of lymphoma. The remaining 26 patients underwent laparotomy because of presumed benign disease. Twenty patients were found to have localized disease at laparotomy. Patients with localized disease demonstrated significantly better survival than patients with extranodal and nodal involvement (p less than 0.05). Four patients with local resection received no adjuvant therapy and were free of disease a median of 50 months after surgery.

Abdominal Neoplasms↗

PubMed1987

Monoclonal antibody-mediated modulation of parathyroid hormone secretion by dispersed parathyroid cells.

Available data suggest that ionized calcium may interact with a cell surface "sensor" or "receptor" to produce changes in one or more intracellular second messengers that ultimately regulate the release of parathyroid hormone (PTH). Recently, we developed a series of monoclonal antibodies directed toward specialized differentiation antigens expressed on endocrine cells. Since many of these monoclonal antibodies displayed exquisite specificity for cell surface molecules on the parathyroid cell, we used these reagents as probes to investigate signal recognition/transduction mechanisms associated with abnormal calcium-regulated PTH secretion. Depending on their binding site on the respective target antigen molecules, these monoclonal antibodies either stimulated or inhibited hormone secretion. Thus, defects in membrane-associated structures may contribute to deranged calcium-regulated PTH secretion in abnormal parathyroid cells.

Antibodies, Monoclonal↗

PubMed1987

Application of microencapsulation for toxicology studies. II. Toxicity of microencapsulated trichloroethylene in Fischer 344 rats.

Gelatin-sorbitol microcapsules containing 44.1% trichloroethylene (TCE) were prepared and mixed in NIH-07 rodent meal diet and provided at microcapsule concentrations of 0 (untreated control group), 1.25, 2.5, 5.0, or 10% (equivalent to 0, 0.55, 1.10, 2.21, or 4.41% TCE, respectively) to groups of 10 male F344 rats for 14 days. An additional control group received diets containing 5% empty capsules. For comparisons, TCE dissolved in corn oil was administered by gavage to different groups of 10 male rats for 14 consecutive days at dose levels adjusted to correspond to those in the feed study. Treatment-related deaths occurred only in the highest dose group of the gavage study. Body weight gain and feed consumption were reduced in high-dose groups of both the feed and gavage studies. There was no measurable loss of TCE in feed sampled from the cages during the study. Dose-related increases in organ (liver and kidney) weight/body weight ratios, individual cell necrosis in the liver, and hepatic microsomal NADPH cytochrome c reductase and peroxisomal palmitoyl-CoA oxidase and catalase activities were found in both the dosed-fed and gavage groups. Induction of cytochrome P-450 occurred only in the dosed-feed study. There were no significant compound-related pathologic lesions observed in the kidneys, the only other organ examined microscopically. Differences in lethality, cytochrome P-450 levels, and induction of microsomal or peroxisomal enzyme activities were attributed to differences in the method of dosing (gavage versus dosed-feed). The demonstration of no significant loss of TCE from the feed and of similar toxic effects produced by microencapsulated TCE via feed and TCE in corn oil via gavage indicate that microencapsulation can provide an excellent alternative exposure route for studying the oral toxicological properties of volatile chemicals, such as TCE, in rats.

Animal Feed↗

PubMed1987

Splenic enlargement and hyperfunction as indications for splenectomy in chronic leukemia.

The chronic leukemias are associated with significant morbidity from splenic enlargement and hyperfunction. Although some patients with chronic leukemia benefit from splenectomy, the indications for operation are unclear. To identify those patients who benefit most from splenectomy, nine patients with chronic lymphocytic leukemia (CLL) and eight patients with chronic granulocytic leukemia (CGL) who had splenectomy to palliate the symptoms of massive splenic bulk or to improve the hematologic sequelae of splenic hyperfunction were studied. Splenectomy for bulk symptoms provided good palliation of symptoms, but the duration of the benefit was limited by the stage of the disease. Five of eight patients with CGL with bulk symptoms died within 6 months of operation. Splenectomy for hyperfunction was limited to a short-term hematologic response. In three of four patients with CLL who were Coombs positive, the presence of autoantibodies correlated with a recurrent transfusion requirement within 3 months of splenectomy. Thus, the benefit of splenectomy for bulk symptoms must be weighed against the risk of surgery and the patient's limited life expectancy. The benefit of splenectomy for treatment of splenic hyperfunction depends on the stimulus to hyperfunction and may not be beneficial for patients with refractory autoimmune anemias.

Adult↗

PubMed1987

Recommendations for the surgical management of advanced breast cancer.

By judicious selection of patients and operative procedures, the surgeon has an opportunity to improve the quality of life and to enhance disease-free survival in specific patient sub-groups, despite the fact that the local breast cancer may be advanced and untreated.

Breast Neoplasms↗

PubMed1986

Complete nucleotide sequence of the Escherichia coli ptr gene encoding protease III.

The nucleotide sequence of a 3120 bp region of the E. coli chromosome that includes the entire ptr gene has been determined. The proposed coding region for Protease III is 2889 nucleotides long, which would encode a protein consisting of 962 amino acids with a calculated molecular mass of 107,719 daltons. The predicted primary structure of the protein includes a 23-residue signal sequence, cleavage of which would give rise to a mature protein of molecular mass 105,124 daltons. At its 3' end, the ptr gene overlaps the start of the recB coding sequence by 8 bases, suggesting that these genes may form part of an operon.

Amino Acid Sequence↗

PubMed1986

Complete nucleotide sequence of the Escherichia coli recC gene and of the thyA-recC intergenic region.

The nucleotide sequence of a 6,000 bp region of the E. coli chromosome that includes the 3' end of the coding region for the thyA gene and the entire recC gene has been determined. The proposed coding region for the RecC protein is 3369 nucleotides long, which would encode a polypeptide consisting of 1122 amino acids with a calculated molecular mass of 129 kDa. Mung bean nuclease mapping of a recC specific transcript produced in vivo indicates that transcription of recC is initiated 80 bp upstream of the translational start point. A weak promoter sequence situated 5' to the transcription initiation point has been identified. In the 1953 bp thyA-recC intergenic region there are three open reading frames that would code for polypeptides of molecular mass 30 kDa, 13.5 kDa and 12 kDa, respectively. Although the first and third of these open reading frames are preceded by possible ribosome binding sites, no obvious promoter sequences could be identified. Moreover, transcripts for these reading frames could not be detected.

Amino Acid Sequence↗

PubMed1986

Characterization of a new monoclonal antibody to a cell surface antigen on colorectal cancer and fetal gut tissues.

Murine hybridoma were raised against the human colon carcinoma cell line CL-187. One clone was found to secrete a monoclonal antibody (ND-1) that recognizes a large external antigen (LEA) on human colon carcinoma cells. With indirect immunofluorescence on formaldehyde-fixed cells, more than 90% of the human colorectal carcinoma cell lines tested expressed LEA. Almost all of the 46 human noncolorectal and nonhuman cell lines tested did not express LEA, including cancer cell lines from other endodermally derived tissues. Staining of frozen sections from human colorectal tumors, noncolorectal tumors, normal adult, and normal fetal tissues showed expression of the antigen on colorectal cancer tissue, fetal colon, and fetal biliary epithelium. LEA can also be detected in the serum and ascites of colorectal cancer patients. Double indirect immunofluorescence with rabbit anti-carcinoembryonic antigen (CEA) antibody and ND-1 monoclonal antibody on a human colorectal carcinoma cell line showed that LEA is distinct from CEA. Physicochemical analysis of LEA showed that it has a large molecular weight, is resistant to extraction from the cell surface, and that sialic acid is an important component of the antigenic site. Because of the specificity for colorectal cancer tissue along with certain biochemical properties, LEA appears to be unique when compared with other tumor-associated antigens. Further research is needed to define the clinical usefulness of LEA in either the diagnosis or treatment of colorectal carcinoma.

Animals↗