Biomedical subjects

C O Starnes

Publications and source records attributed to C O Starnes.

17 recordsLinked to original sources

PubMed1998

Keratinocyte growth factor protects mice from chemotherapy and radiation-induced gastrointestinal injury and mortality.

Keratinocyte growth factor (KGF) stimulates the proliferation and differentiation of epithelial cells including those of the gastrointestinal tract. Although chemotherapeutics and radiation exposure kill rapidly proliferating tumor cells, rapidly dividing normal cells of the host's gastrointestinal tract are also frequently damaged, leading to the clinical condition broadly termed "mucositis." In this report, recombinant human KGF used as a pretreatment in several mouse models of chemotherapy and/or radiation-induced gastrointestinal injury significantly improved mouse survival. Using multiple-dose 5-fluorouracil, methotrexate, and radiation in combination and total body radiation alone models, KGF increased survival by 55% or greater. In the models that used chemotherapy with or without radiation, KGF significantly ameliorated weight loss after injury and accelerated weight gain during recovery. The basis of these systemic benefits appears to be due in part to the trophic effects of the growth factor on the intestinal epithelium because KGF pretreatment caused an increase in measures of mucosal thickness (villus height and crypt depth) that persisted during the course of 5-fluorouracil chemotherapy. Treatment with KGF also afforded a 3.5-fold improvement in crypt survival in the small intestine, suggesting that KGF also has a direct effect on the crypt stem cells. These data indicate that KGF may be therapeutically useful to lessen the intestinal side effects of current cancer therapy regimens.

Animals↗

PubMed1998

Combined treatment of acute EAE in Lewis rats with TNF-binding protein and interleukin-1 receptor antagonist.

Experimental autoimmune encephalomyelitis (EAE) is a term given to describe a collection of animal models representing the human disease multiple sclerosis (MS). Although not fully understood, the involvement of cytokines and the immune system in either EAE or human MS is well established. Past efforts have shown that inhibition of proinflammatory cytokines tumor necrosis factor (TNF-alpha) or interleukin-1 (IL-1) result in amelioration of acute EAE in Lewis rats. The present study examined this model for the effect of concomitant inhibition of both TNF-alpha and IL-1, which resulted in a modest but significant therapeutic effect that was superior to inhibition of either single agent alone with respect to four of the five variables used to follow the progression of disease in this model, i.e., clinical severity, frequency of disease, loss of body weight, and day of onset. These results are in accordance with the idea that combination treatments are likely to prove superior to single agent therapy in the treatment of autoimmune inflammatory disease.

Animals↗

PubMed1995

Keratinocyte growth factor is an important endogenous mediator of hair follicle growth, development, and differentiation. Normalization of the nu/nu follicular differentiation defect and amelioration of chemotherapy-induced alopecia.

The growth and development of hair follicles is influenced by a number of different growth factors and cytokines, particularly members of the fibroblast growth factor (FGF) family. Keratinocyte growth factor (KGF or FGF-7) is a recently identified 28-kd member of the FGF family that induces proliferation of a wide variety of epithelial cells, including keratinocytes within the epidermis and dermal adnexa. Because KGF induces marked proliferation of keratinocytes, and both KGF and KGF receptor (KGFR) mRNA are expressed at high levels in skin, we sought to localize KGF and KGFR in skin by in situ hybridization. KGFR mRNA was relatively strongly expressed by keratinocytes in the basilar epidermis as well as throughout developing hair follicles of rat embryos and neonates. KGF mRNA was expressed at lower levels than was KGFR but could be localized to follicular dermal papillae in rat embryos and neonates. These results prompted us to investigate the effects of KGF on hair follicles in two distinct murine models of alopecia. In the first model, recombinant KGF (rKGF) induced dose-dependent hair growth over most of the body in nu/nu athymic nude mice when administered intraperitoneally or subcutaneously over 17 to 18 days. When administered subcutaneously, rKGF induced the most extensive hair growth at the sites of injection. Histologically, rKGF induced marked follicular and sebaceous gland hypertrophy, a normalization of the nu/nu follicular keratinization defect, and an increase in follicular keratinocyte proliferation as assessed by bromodeoxyuridine labeling. In the second model, a neonatal rat model of cytosine arabinoside chemotherapy-induced alopecia in which interleukin-1, epidermal growth factor, and acidic FGF have all demonstrated some degree of alopecia cytoprotection, rKGF induced a dose-dependent cytoprotective effect, abrogating as much as 50% of the alopecia in this model when administered beginning 1 day before the onset of chemotherapy. Taken together, these data suggest that KGF is an important endogenous mediator of normal hair follicle growth, development, and differentiation.

Alopecia↗

PubMed1994

Coley's toxins, tumor necrosis factor and cancer research: a historical perspective.

As far back as the 1700s, it was recorded that certain infectious disease processes could exert a beneficial therapeutic effect upon malignancy. Most prominent among the numerous deliberate efforts made to take advantage of these observations was that of a pioneering New York surgeon, William B. Coley, active career 1891-1936. Using a bacterial vaccine to treat primarily inoperable sarcoma. Coley accomplished a cure rate of better than 10%. This review examines the history of these efforts and presents a discussion of their corresponding relevance to present day immunotherapy.

Bacterial Toxins↗

PubMed1992

Coley's toxins.

Explore the source record for details and available documents.

Animals↗

PubMed1992

Coley's toxins in perspective.

Despite initial hopes, the efficacy of tumour necrosis factor in treating cancer patients has been disappointing. But a more careful selection of patients, and more appropriate treatment, might be fruitful.

Bacterial Vaccines↗

PubMed1988

Alternative V kappa gene rearrangements in a murine B cell lymphoma. An explantation for idiotypic heterogeneity.

Idiotype variants of 38C13, a murine B cell lymphoma, have been isolated by immunoselection with antiidiotype mAbs. The V region genes for the kappa light chains and mu heavy chains expressed by these tumor cells were sequenced and compared. There was no evidence for V region somatic point mutation in this tumor. However, while the heavy chain genes were all identical, the light chain genes were all different. The light chain genes of each variant were derived from the V kappa-Ox1 gene family and joined to J kappa 4, whereas the light chain gene of the parental tumor was derived from the V kappa 9 family and joined to J kappa 2. Two of the variants used the identical V kappa gene but differed by the inclusion of a variable number of additional nucleotides in the V/J joint. Thus, the idiotypic heterogeneity of this B cell lymphoma arises as a consequence of alternative light chain rearrangements rather than point mutation. This process repetitively uses members of the same V kappa gene family. Two of the variants use the identical V kappa and J kappa gene segments but differ by the presence of extra nucleotides at the V kappa/J kappa joint.

Amino Acid Sequence↗

PubMed1988

Heterogeneity of a murine B cell lymphoma. Isolation and characterization of idiotypic variants.

mAb directed toward the idiotype of the 38C13 murine B cell lymphoma can be used to treat and cure a high percentage of mice challenged previously with an otherwise lethal dose of tumor cells. Tumors developing in animals despite antibody therapy were examined by immunofluorescence and found to demonstrate either loss of surface Ig, or expression of an altered idiotype that no longer bound the antibody used for treatment. Further immunofluorescence analysis of the variant tumors revealed individual patterns of cross-reactivity with anti-38C13 idiotype mAb other than that used for therapy. The variant tumor cells were fused to myeloma cells and hybrids were isolated which secreted large quantities of the altered idiotype proteins. Polyclonal antibodies and mAb prepared against the mutant proteins demonstrated cross-reactivity with the original 38C13 protein and its other variants. But the variants and wild type cells could be distinguished from each other by their patterns of reactivity with the panels of anti-idiotype antibodies. Differences in apparent m.w. were demonstrated in the L chains of each of the mutant proteins. Southern blot analysis of the H chain locus of these mutants established that they were all clonally related; however, the L chain loci were grossly different. Thus, rare cells with alteration in their Ig L chain genes and expressed proteins can give rise to idiotype variants in this B cell tumor.

Animals↗

PubMed1988

Specific enhancement of the therapeutic effect of anti-idiotype antibodies on a murine B cell lymphoma by IL-2.

We have previously reported on the augmentation of monoclonal anti-Id antibodies by IL-2 in the therapy of a murine B cell lymphoma. The mechanism of this augmentation was through the expansion by IL-2 of effector cells mediating antibody-dependent cellular cytotoxicity. In this paper we explore the power of IL-2 to enhance anti-Id therapy on larger tumor burdens and at sites distant from the site of injection. The combination treatment was able to induce regression of established 1-cm s.c. tumors associated with microscopic metastatic tumor in lungs, liver, and spleen. Further studies into the mechanism of activity showed that IL-2 was unable to augment in vivo or in vitro tumor lysis by F(ab')2 fragments, thus emphasizing the importance of Fc interactions with antibody-dependent cellular cytotoxicity effector cells. FcR-bearing NK cells were increased in the peritoneum of IL-2-treated mice. The augmented therapeutic effect by the combination treatment was specific for tumor cells expressing the target Id, and non-specific cytotoxicity on Id-negative variants was not seen.

Animals↗

PubMed1980

Mode of action of sesquiterpene lactones as anti-inflammatory agents.

Sesquiterpene lactones containing an alpha-methylene-gamma-lactone moiety were shown to be potent inhibitors of carrageenan-induced edema and chronic adjuvant-induced arthritis in rodents at 2.5 mg/kg/day. The mode of action of sesquiterpene lactones as anti-inflammatory agents appeared to be at multiple sites; for example, at 5 X 10(-4) M, the sesquiterpene lactones effectively uncoupled the oxidative phosphorylation of human polymorphonuclear neutrophils and elevated the cyclic adenosine monophosphate levels of rat neutrophils and rat and mouse liver cells. Free and total lysosomal enzymatic activity was inhibited by these agents at 5 X 10(-4) M in both rat and mouse liver and rat and human neutrophils. Furthermore, the structure-activity relationships for the stabilization of lysosomal membrane for rat liver cathepsin activity followed the same structural requirement necessary for anti-inflammatory activity; i.e., the alpha-methylene-gamma-lactone moiety contributed the most activity, whereas the beta-unsubstituted cyclopentenone and alpha-epoxycyclopentanone contributed only minor activity. Human polymorphonuclear neutrophil chemotaxis was inhibited at low concentrations (i.e., 5 X 10(-5) and 5 X10(-6) M), whereas prostaglandin synthetase activity was inhibited at a higher concentration (i.e., 10(-3) M) by the sesquiterpene lactones.

Acid Phosphatase↗

PubMed1980

Antihyperlipidemic activity of sesquiterpene lactones and related compounds.

Some naturally occurring pseudoguaianolides and germacranolides as well as synthetic related compounds were observed to be antihyperlipidemic agents in mice. Several of these compounds at a dose of 20 mg/kg/day resulted in lowering of serum cholesterol by approximately 30% and of serum triglycerides by approximately 25%. Thiol-bearing enzymes of lipid synthesis, i.e., acetyl-CoA, citrate-lyase, acetyl-CoA synthetase, and beta-hydroxy-beta-methylglutaryl-CoA reductase, were inhibited by these agents in vitro, supporting the premise that these agents alkylate thiol nucleophiles by a Michael-type addition. The alpha-methylene-gamma-lactone moiety, the beta-unsubstituted cyclopentenone ring, and the alpha-epoxycyclopentanone system of these compounds appeared to be responsible for the lowering of serum lipids.

Animals↗

PubMed1980

Anti-inflammatory activity of amine cyanoboranes, amine carboxyboranes, and related compounds.

Amine cyanoboranes and amine carboxyboranes (boron analogs of alpha-amino acids) were shown to inhibit inflammation. The analogs effectively blocked general inflammation, induced arthritis, and the writhing reflex associated with inflammation pain, while the inflammation associated with pleurisy was marginally inhibited. The boron analogs were shown in vitro to inhibit the release of lysosomal enzymes from liver and polymorphonuclear neutrophils. Furthermore, prostaglandin synthesis was blocked by these agents at a low concentration, i.e., 10(-6) M. Liver oxidative phosphorylation processes also were uncoupled by these agents, but the migration of polymorphonuclear neutrophils was unaltered at 10(-4) M. The elevation of cyclic adenosine monophosphate levels in polymorphonuclear neutrophils correlated positively with in vivo antiarthritic activity. Initial studies in rodents demonstrated that these boron analogs can be used at safe therapeutic doses.

Analgesics↗

PubMed1979

Anti-inflammatory activity of sesquiterpene lactones and related compounds.

Some sesquiterpene lactones and related compounds were tested for anti-inflammatory activity in rodents. In the edema-induced carrageenan inflammation screen, the alpha-methylene-gamma-lactone moiety of the sesquiterpene lactones was required for inhibitory activity. The 6-hydroxy group of helenalin also was required for potency. In the tenulin series, the 2,3-epoxy derivatives were marginally active. The same structure was required for inhibition of the writhing reflex. In the chronic adjuvant arthritic screen, compounds containing the alpha-methylene-gamma-lactone moiety, the beta-unsubstituted cyclopentenone ring, and the alpha-epoxy cyclopentenone system afforded significant inhibition at 2.5 mg/kg/day. The sesquiterpene lactones were marginally effective against induced pleurisy. The delayed hypersensitivity was suppressed by these agents whereas immunoglobulin synthesis was slightly stimulated. No delerious side effects were observed with these agents from the limited tests performed.

Anaphylaxis↗

PubMed1979

Boron betaine analogs: antitumor activity and effects on Ehrlich ascites tumor cell metabolism.

Several newly synthesized boron betaine analogs had antitumor activity in Ehrlich ascites, Walker 256 ascites carcinosarcoma, and Lewis lung screens and marginal activity in the B-16 melanotic melanoma screen. In vivo testing demonstrated that trimethylamine-cyanoborane inhibied Ehrlich ascites cell DNA and protein syntheses as well as gene modulation by chromatin protein phosphorylation and methylation. Trimethylamine-cyanoborane increased cyclic-AMP levels. In vitro testing showed that nuclear DNA polymerase, thymidylate synthetase, S-adenosylmethyltransferase, nonhistone chromatin methylation, deoxyribonuclease, ribonuclease, and cathepsin were inhibited by the boron analogs. These compounds did not demonstrate high antitumor activity at the doses employed, but blockage of methyl transfer from S-adenosylmethionine was established as a feasible method for controlling cell proliferation.

Animals↗

PubMed1978

Antitumor agents XXX: Evaluation of alpha-methylene-gamma-lactone-containing agents for inhibition of tumor growth, respiration, and nucleic acid synthesis.

Evidence is presented that a number of sesquiterpene lactones isolated from plants and synthesized pyrimidines containing the alpha-methylene-gamma-lactone moiety are potent inhibitors of Walker 256 carcinosarcoma and Ehrlich ascites tumor growth and marginal inhibitors of P-388 lymphocytic leukemia and Lewis lung tumor growth. In vitro aerobic basal respiration and oxidative phosphorylation processes of Ehrlich ascites cells were inhibited by these agents as well as deoxyribonucleic acid polymerase and thymidylate synthetase enzymatic activities. These studies indicate that the alpha-methylene-gamma-lactone moiety, the beta-unsubstituted cyclopentenone ring, and the alpha-epoxycyclopentanone system are the essential moieties for inhibition of these biochemical parameters.

Animals↗

PubMed1977

Sesquiterpene antitumor agents: inhibitors of cellular metabolism.

Helenalin and tenulin injected into CF1 male mice bearing Ehrlich ascites tumors inhibit DNA synthesis and DNA polymerase enzymatic activity in the tumor cells. Helenalin inhibited protein synthesis. Both drugs increased the concentration of adenosine 3',5'-monophosphate, and interfered with glycolytic and mitochondrial energy processes. Cholesterol synthesis was also inhibited, resulting in lower serum cholesterol levels in tumor-bearing animals. Data obtained in vitro indicate that the cyclopentenone-bearing sesquiterpene lactone and related compounds do not alkylate puring bases of nucleic acids but rather undergo a Michael-type addition reaction with the sulfhydryl groups of reduced glutathione and l-cysteine. Thus, the inhibition of cellular enzyme activities and metabolism that has been observed with these drugs might be explained by the occurrence of a Michael-type teaction.

Alkylation↗

PubMed1977

Antitumor agents. 21. A proposed mechanism for inhibition of cancer growth by tenulin and helenalin and related cyclopentenones.

Evidence is presented that sesquiterpene lactones or ketones containing the O=CC=CH2 moiety, e.g., tenulin and helenalin, alkylate the thiol group of reduced glutathione and L-cysteine in vitro. A proposal is offered that this mechanism of action is responsible for the observed potent in vivo antitumor activity of these agents in the Ehrlich ascites and Walker 256 carcinosarcoma and to a lesser extent in the P388 leukemic screen. Inhibition of tumor growth is thought to occur due to the O=CC=CH2 system alkylating by rapid Michael addition the SH biological nucleophiles of key regulatory enzymes of nucleic acid and chromatin metabolism. This proposition is in accord with the ability of these agents to inhibit DNA synthesis and gene activity of Ehrlich ascites cells.

Animals↗