Reducing risk factors for eating disorders: targeting at-risk women with a computerized psychoeducational program.

OBJECTIVE: This controlled study evaluated whether an 8-week program offered over the Internet would significantly decrease body image dissatisfaction, disordered eating patterns, and preoccupation with shape/weight among women at high risk for developing an eating disorder. METHOD: Fifty-six college women were recruited on the basis of elevated scores (> or =110) on the Body Shape Questionnaire (BSQ). Psychological functioning, as measured by the Eating Disorder Inventory Drive for Thinness (EDI-DT) subscale, Eating Disorder Examination-Questionnaire (EDE-Q), and the BSQ, was assessed at baseline, posttreatment, and at 10-week follow-up. RESULTS: All participants improved over time on most measures, although effect sizes suggest that the program did impact the intervention group. DISCUSSION: Findings suggest that technological interventions may be helpful for reducing disordered eating patterns and cognitions among high-risk women. Future research is needed to assess whether such programs are effective over time for prevention of and reduction in eating disorder symptomatology.

Effectiveness of an Internet-based program for reducing risk factors for eating disorders.

This study evaluated an Internet-delivered computer-assisted health education (CAHE) program designed to improve body satisfaction and reduce weight/shape concerns--concerns that have been shown to be risk factors for the development of eating disorders in young women. Participants were 60 women at a public university randomly assigned to either an intervention or control condition. Intervention participants completed the CAHE program Student Bodies. Measures of body image and disordered eating attitudes were assessed at baseline, postintervention, and 3-month follow-up. At follow-up, intervention participants, compared with controls, reported a significant improvement in body image and a decrease in drive for thinness. This program provides evidence for the feasibility and effectiveness of providing health education by means of the Internet.

Therapeutic effects of a synthetic peptide of C-reactive protein in pre-clinical tumor models.

Previous studies have shown that multilamellar vesicles (MLV) or other carriers containing purified human C-reactive protein (CRP) have therapeutic activity in preclinical tumor models. Here we evaluated the therapeutic effects of MLV containing novel synthetic peptides, derived from the structure of CRP, on the extent of (a) established lung metastases of fibrosarcoma T241 in C57Bl/6 mice, (b) survival of C57Bl/6 mice bearing established liver metastases of colon carcinoma MCA-38, and (c) primary tumor growth of Renca renal carcinoma in Balb/c mice. In all cases, a single synthetic CRP peptide, RS-83277, demonstrated significant antitumor effects comparable to that seen with intact CRP. Two other synthetic CRP peptides, RS-83287 and RS-83147, showed no therapeutic activity and were comparable to control MLV containing only buffer. None of the peptides contained sequences homologous with that of the phagocyte stimulant, tuftsin. Activity of MLV-encapsulated RS-83277 was dose-dependent, and a comparable dose of the soluble peptide, given either alone or following injection of buffer-MLV, was ineffective. These results demonstrate immunotherapeutic potential for a novel synthetic peptide derived from CRP, and endogenous acute-phase protein.

Inhibition of vesicular stomatitis virus replication in dexamethasone-treated L929 cells.

We previously demonstrated that dexamethasone treatment of L929 cells inhibited plaque formation by vesicular stomatitis virus (VSV), encephalomyocarditis virus, or vaccinia virus. We now have characterized the antiviral effects of glucocorticoids in L929 cells. Dexamethasone did not directly inactivate VSV nor did steroid treatment of L929 cells affect virion adsorption or penetration. The VSV yield in L929 cells treated with dexamethasone for a period of only 4 or 8 hr was decreased by 50% when cells were infected the day following steroid treatment. Treating L929 cells with dexamethasone for a longer period resulted in greater inhibitions of virus synthesis. Interferon activity (less than 5 units/ml) was not detected in L929 cell culture fluids and cell sonicates from steroid-treated cells and the addition of antiserum to murine alpha/beta-interferon had no effect on the ability of dexamethasone to inhibit VSV replication. Dexamethasone treatment of L929 cells did not induce the production of double-stranded RNA-dependent protein kinase but did result in a slight elevation of 2-5A oligoadenylate synthetase activity, two enzymatic activities associated with the antiviral state induced by interferon. However, the elevated 2-5A synthetase activity was not associated with an inhibition of VSV RNA accumulation in dexamethasone-treated L929 cells. By contrast, the synthesis of all five VSV proteins was reduced by 50-75% in dexamethasone-treated L929 cells as early as 4 hr after infection. Thus, the dexamethasone-mediated inhibition of VSV replication in L929 cells is associated with decreased production of VSV structural proteins.

Inhibition of epidermal growth factor/transforming growth factor-alpha-stimulated cell growth by a synthetic peptide.

Estrogen-stimulated growth of the human mammary adenocarcinoma cell line MCF-7 is significantly inhibited by monoclonal antibodies to the epidermal growth factor (EGF) receptor that act as antagonists of EGF's mitogenic events by competing for high-affinity EGF receptor binding sites. These antibodies likewise inhibit the EGF or transforming growth factor-alpha (TGF-alpha)-stimulated growth of these MCF-7 cells. An analogous pattern of specific EGF or TGF-alpha growth inhibitory activity was obtained using a synthetic peptide analog encompassing the third disulfide loop region of TGF-alpha, but containing additional modifications designed for increased membrane affinity [( Ac-D-hArg(Et)2(31),Gly32,33]HuTGF-alpha(31-43)NH2). The growth factor antagonism by this synthetic peptide was specific in that it inhibited EGF, TGF-alpha, or estrogen-stimulated growth of MCF-7 cells but did not inhibit insulin-like growth factor-1 (IGF-1)-stimulated cell growth. Altogether, these results suggest that a significant portion of the estrogen-stimulated growth of these MCF-7 cells is mediated in an autocrine/paracrine manner by release of EGF or TGF-alpha-like growth factors. The TGF-alpha peptide likewise inhibited EGF- but not fibroblast growth factor (FGF)- or platelet-derived growth factor (PDGF)-stimulated growth of NIH-3T3 cells in completely defined media; but had no effect on growth or DNA synthesis of G0-arrested cells, nor did it effect growth of NR-6 cells, which are nonresponsive to EGF. Although this synthetic peptide did not directly compete with EGF for cell surface receptor binding, it exhibited binding to a cell surface component (followed by internalization), which likewise was not competed by EGF. The peptide did not directly inhibit EGF-stimulated phosphorylation of the EGF receptor, nor did it inhibit phosphorylation of an exogenous substrate, angiotensin II, by activated EGF receptor. The TGF-alpha peptide did, however, affect the structure of laminin as manifested by laminin self-aggregation; this affect on laminin may, in turn, have a modulatory effect on EGF-mediated cell growth.

Prevention of doxorubicin-induced hematotoxicity in mice by interleukin 1.

Interleukin 1 alpha and interleukin 1 beta induce peripheral neutrophilia with stimulation of granulopoiesis in bone marrow. The continuous administration of interleukin 1 (100 ng/day) to mice for 7 days by s.c.-implanted Alzet osmotic minipumps induced marked stimulation of granulopoiesis in marrow and spleen in normal mice, and protected against the marked depletion of myeloid and erythroid cells in bone marrow of mice treated with single injections of either 20 or 30 mg/kg doxorubicin (DXN). Interleukin 1 beta infusion also protected against DXN-induced atrophy of thymus and secondary lymphoid organs. Single i.p. injection of either interleukin 1 alpha or interleukin 1 beta at doses up to 1000 ng 24 h prior to treatment with DXN did not protect against the hematopoietic and lymphoid toxicities of DXN.

Liposomal interferon-beta: sustained release treatment of simian varicella virus infection in monkeys.

Liposomal formulations (distearoylphosphatidylcholine:dipalmitoylphosphatidylglycerol, 9:1) of recombinant human interferon-beta ser17 (IFN-beta), administered im to African green monkeys at doses of 10(7) units/kg on days 1 and 6 after infection with simian varicella virus, resulted in partial protection of the monkeys from viral infection. Aqueous interferon administered under the same dosing regimen was ineffective. When given at 10(6) units/kg per dose twice daily for 10 d, however, it was highly effective in reducing viremia and rash. The antiviral efficacy obtained with the liposomal IFN-beta formulation given in two injections 5 d apart was thus significantly more efficacious than aqueous IFN-beta given in the same dosing regimen. However, it was not as efficacious as repeated, twice-daily injections of aqueous IFN-beta. Thus, im-injected liposomal IFN-beta, which results in sustained release of the IFN-beta from the injection site, exerts antiviral efficacy in a primate model superior to that obtained with the identical dosing regimen of aqueous IFN-beta.

Enhanced antitumor efficacy of adriamycin in combination with interferon-gamma: effects on macrophages.

The combination of the immunomodulator interferon-gamma (IFN-gamma) with the chemotherapeutic drug adriamycin (ADM) was assessed in vitro and in vivo in murine tumor models. When tested in vivo against the murine Lewis lung carcinoma, significantly greater reduction of spontaneous pulmonary metastases was obtained by combination treatment with IFN-gamma, followed 1 day later by ADM. Intraperitoneal ADM treatment also resulted in an increased recruitment of peritoneal mononuclear cells. It is noteworthy that, although the antitumor efficacy was significantly increased by the IFN-gamma/ADM combination treatment, gross toxicity of ADM was not increased. Thus, a net increase in the therapeutic index of ADM was achieved. In vitro, the effects of ADM on the ability of murine peritoneal macrophages, with or without the addition of immunological macrophage activators, to kill tumor cells was studied. Resident macrophages were able to sequester ADM (when present at 10 micrograms/ml) from the medium, and could subsequently mediate killing of target tumor cells. However, incubation of macrophages with low (ineffective by themselves) doses of ADM (1 microgram/ml) prevented their simultaneous or subsequent activation to the tumoricidal state after incubation with the normal macrophage-activating mixture of IFN-gamma plus a muramyl dipeptide (MDP) analog. When the order of addition of reagents was reversed such that the macrophages were preincubated for 24 hr with IFN-gamma (100 U/ml) plus the MDP analog (0.1-10 micrograms/ml), no antagonism of tumoricidal activity was obtained upon subsequent incubation with ADM. There were no interactions between IFN-gamma and ADM on the direct proliferation of tumor cells. Taken together, these results suggest that the enhanced antitumor efficacy of IFN-gamma/ADM combinations in vivo was not due to direct antiproliferative effects on the tumor cells, but rather may be mediated by direct cytotoxicity of ADM on tumor cells enhanced by phagocytic mononuclear cells.

Alternative delivery systems for peptides and proteins as drugs.

The emergence of recombinant DNA technology has resulted in the large-scale production of a myriad of genetically engineered proteins and peptides, making many of them available for the first time for potential use as therapeutic entities. In addition, increased knowledge in the area of peptide/polypeptide hormones has resulted in an expansion of research efforts utilizing peptide synthetic chemistry, aimed toward developing novel therapeutic peptide drugs. Proteins and peptides cannot readily be administered by the conventional oral route, and thus alternative delivery methods to circumvent the necessity of frequent injections are being explored. This article reviews the current state-of-the-art technology of such methodologies, encompassing localized administration, administration to various body cavities (i.e., nasal, rectal, etc.), as well as controlled-release injectable or implantable systems. These different approaches result in quite different pharmacokinetics that may in part dictate which approach is best suited for a particular protein or peptide.

Effect of 9-(1,3-dihydroxy-2-propoxymethyl)guanine and recombinant human beta interferon alone and in combination on simian varicella virus infection in monkeys.

Treatment of viral infections with combinations of antiviral agents may permit administration of reduced doses of either or both drugs. Lowered doses may reduce associated toxicity. Intravenous administration of substantial doses of either human recombinant beta interferon (rHuIFN-beta) or 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) prevents development of simian varicella virus infection in African green monkeys. Daily doses of 2 X 10(6) U of rHuIFN-beta/kg inhibited clinical disease in monkeys inoculated with simian varicella virus, and doses of DHPG between 20 and 60 mg/kg per day were necessary for similar antiviral effects. Intravenous administration of combinations of rHuIFN-beta and DHPG permitted an approximately 100-fold reduction in the effective dose of rHuIFN-beta and a 10-fold reduction in the effective dose of DHPG. Analysis of data relating to viremia by using the method of the median-effect principle showed the combination of rHuIFN-beta and DHPG was strongly synergistic in treatment of this infection.

Vaccinia virus and the EGF receptor: a portal for infectivity?

We previously demonstrated that occupancy of the epidermal growth factor (EGF) receptor reduced the ability of vaccinia virus to infect L cells [Eppstein et al: Nature 318:663, 1985]. This result suggested that vaccinia virus was utilizing the EGF receptor as one pathway to infect cells. We have studied this system further, and now find that antibodies to the EGF receptor also reduce the ability of vaccinia virus to infect cells productively. Inclusion of both EGF and antibodies to the EGF receptor did not cause inhibition over that obtained by EGF alone, providing another line of evidence that the antiviral effects on vaccinia virus were at the level of the EGF receptor. The antiviral effects of EGF or synthetic peptides corresponding to the third disulfide loop of TGF-alpha or the vaccinia virus growth factor were specific to vaccinia virus and did not inhibit replication of herpes simplex virus type 2 or vesicular stomatitis virus. The inhibitory effects on replication of vaccinia virus were obtained when EGF (but not insulin or growth hormone) was present prior to, but not after, productive viral adsorption. These results provided further evidence that the antivaccinia viral effects of EGF were at the level of initial receptor occupancy. As interferon (IFN) treatment has been shown to interfere with the action of some growth factors, including EGF, we examined the effects of IFN treatment of cells on the antivaccinia viral activity of EGF. Our results show that the antivaccinia effect of IFN-beta either interfered with or partially coalesced with the inhibitory effects of EGF.(ABSTRACT TRUNCATED AT 250 WORDS)

Stereoconfiguration markedly affects the biochemical and biological properties of phosphorothioate analogs of 2-5A core, (A2'p5')2A.

The diester bonds of phosphorothioate trimer analogs of (A2'p5')2A (2-5A core) of the Sp stereoconfiguration were found to be extremely stable to hydrolysis by both serum and cellular phosphodiesterases. The corresponding Rp isomers, although still more stable than parent ppp(A2'p5')2A (2-5A), were significantly more susceptible to enzymatic hydrolysis than were the Sp isomers. Utilization of these novel 2-5A trimer isomers containing various combinations of Sp or Rp configurations at the internucleotidic phosphorothioate linkages revealed a further specificity of this enzymatic hydrolysis. Thus, the stereoconfiguration of the bond adjacent to the one undergoing hydrolysis influenced the rate of enzymatic hydrolysis, as well as did the chain length of the oligomer. The most stable trimer analog, which contained both internucleotide phosphorothioate linkages of the Sp configuration, had a half-life of 30 days in serum, which is a 1500-fold increase over that of parent 2-5A core. This is the first report on biochemical stability of an oligonucleotide containing more than one phosphorothioate linkage of the Sp configuration and is the first demonstration that a phosphorothioate internucleotide bond of the Sp configuration can increase the enzymatic stability of an adjacent phosphorothioate bond. In marked contrast to all previous 2-5A core analogs of increased stability, the activity (antiproliferative and antiviral) of the stable phosphorothioate 2-5A core analogs was obtained with the intact trimer, i.e., it was not attributed to antimetabolite degradation products.

Epidermal growth factor receptor occupancy inhibits vaccinia virus infection.

Vaccinia virus encodes VGF, an early protein of relative molecular mass 19,000 (19K) which, from amino-acid residues 45 to 85, is homologous in 19 residues to epidermal growth factor (EGF), and transforming growth factor-alpha (TGF-alpha). The conserved sequence includes a region of high homology (6 out of 10 amino acids) from residues 71 to 80, corresponding to the third disulphide loop of both EGF and TGF-alpha. This region has recently been shown to contain a binding region of TGF-alpha for the EGF receptor, and this raises the question of whether vaccinia virus utilizes the EGF receptor in order to bind to and infect cells. We now show that occupancy of the EGF receptor inhibits vaccinia virus infection. Inhibition is observed in a dose-dependent fashion by pre-treatment with either EGF or synthetic decapeptide antagonists of EGF's mitogenic activity which correspond to the sequence of the third disulphide loop of VGF or TGF-alpha. The relative ability of the peptides to inhibit vaccinia virus infection parallels their binding affinity to the EGF receptor.

Biological activity of liposome-encapsulated murine interferon gamma is mediated by a cell membrane receptor.

Recombinant murine gamma interferon (rMuIFN-gamma) was found to bind reversibly to a specific high-affinity surface receptor on L929 cells; neither murine alpha or beta nor human gamma IFN competed for receptor binding. Encapsulation of the rMuIFN-gamma in either negatively or positively charged liposomes reduced its immediate ability to bind to this surface receptor. Disruption of liposome integrity with detergent resulted in full ability of the rMuIFN-gamma to bind to the membrane receptor. Incubation of the liposomal IFN in serum-containing medium resulted in significant leakage so that the IFN was able to bind to its surface receptor. Assessment of the biological activity of the rMuIFN-gamma preparations revealed that full antiviral activity was observed in vitro with the liposomal IFN preparations without their prior disruption by detergent. The antiviral activity observed with either free or liposomal IFN was neutralized completely by antibodies against rMuIFN-gamma. Both free and liposomal rMuIFN-gamma, in conjunction with bacterial lipopolysaccharide, were also able to activate murine peritoneal macrophages to the tumoricidal state. Again, this activity of both free and liposomal IFN could be neutralized completely by antibody. These results indicate that although rMuIFN-gamma can be effectively incorporated into liposomes, it must ultimately leak out of the liposome in order to mediate its biological effects; these effects are triggered after the IFN binds to its cell surface receptors.

Enhanced efficacy of the acyclic nucleoside 9-(1,3-dihydroxy-2-propoxymethyl)guanine in combination with gamma interferon against herpes simplex virus type 2 in mice.

The acyclic nucleoside 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) and recombinant mouse interferon gamma (rMuIFN-gamma) were evaluated for their efficacy alone and in combination against a herpes simplex virus type 2 systemic infection in mice. Intraperitoneally infected animals were treated once a day with the drugs at various concentrations for 5 days starting 24 h after inoculation. DHPG was given subcutaneously and rMuIFN-gamma intraperitoneally. For DHPG, the effective dose at which 50% of the mice survived (ED50 was lowered approximately 10-fold from 3.4 to 0.25 mg/kg when given in combination with an ineffective dose of 4MuIFN-gamma (10(3) units per mouse). For rMuIFN-gamma, the ED50 was lowered greater than 10-fold from 6 x 10(3) to less than 3 x 10(2) units per mouse when given in combination with a marginally effective dose of DHPG (1 mg/kg). Construction of an isobologram and calculation of the corresponding fractional protective dose index (less than 0.12 where values less than or equal to 0.5 are considered synergistic) indicates an enhanced protective interaction by the combination of the two drugs.

Synergistic effect of glucantime and a liposome-encapsulated muramyl dipeptide analog in therapy of experimental visceral leishmaniasis.

A regimen of immunostimulation with 6-0-stearoyl-N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine, a lipophilic analog of muramyl dipeptide, combined with antimonial drug therapy was evaluated in the treatment of visceral leishmaniasis of mice and hamsters. The combined treatment was found to be more effective in the elimination of Leishmania donovani amastigotes from infected tissue macrophages than was either of the two treatments applied individually. In mice, it was found that immunostimulation of animals prophylactically, therapeutically, or both enhanced the effects of the antimonial drug (Glucantime) administered more than 1 week after a challenge of BALB/c and C57BL/6 mice. The superiority of the combined treatment of the parasite infection was demonstrable in both short-term (14 days) and long-term (40 to 45 days) infections of the two inbred strains of mice. The combined therapy was also effective in preventing the lethal course of leishmaniasis in hamsters which succumb to disseminated disease in the absence of therapeutic intervention. The efficacy of this dual approach to the therapy of disseminated leishmaniasis of experimental animals holds promise for similar application in the treatment of similarly afflicted human populations.

Cordycepin analogs of ppp5'A2'p5'A2'p5'A (2-5A) inhibit protein synthesis through activation of the 2-5A-dependent endonuclease.

Analogs of the triphosphate 2'-5'-linked adenylate trimer (ppp5'A2'p5'A2'p5'A, called 2-5A) which contain 3'-deoxyadenosine (cordycepin) instead of adenosine either in positions one and two, or in all three positions, are 10-100-fold less potent than is parent 2-5A in inhibition of protein synthesis in intact cells, when utilizing calcium co-precipitation techniques to introduce the 5'-triphosphate oligonucleotides into the cells. That the inhibition of protein synthesis was a consequence of activation of the 2-5A-dependent endonuclease by the 3'-deoxyadenosine analogs of 2-5A was demonstrated in obtaining the ribosomal RNA cleavage pattern that is characteristic of endonuclease activation by parent 2-5A. Additional results (i.e. lack of activity by the dimer species ppp5'(3'dA)2'p5'-(3'dA) or the monomer 3'dA) as well as kinetic analysis both in intact cells and in cell-free extracts provided further evidence that the inhibition of protein synthesis observed with these 3'-deoxyadenosine 2-5A analogs was not due to their degradation to the antimetabolite monomer unit 3'-deoxyadenosine.

2-5A analogs as mechanistic probes of the 2-5A system: stereoconfiguration of phosphorothioate analogs of 2-5A markedly influences metabolic stability.

The stereoconfiguration of the diester bond of phosphorothioate analogs of 2-5A strongly influenced lability to enzymatic hydrolysis by cellular and serum phosphodiesterases. Bonds containing the Sp configuration were extremely resistant to hydrolysis compared to the corresponding Rp configuration linkages. The rate of hydrolysis of the diester bond was influenced by chain length of the adenylate oligomer, with a stability ranking of dimer greater than trimer greater than tetramer; as well as by the stereo-configuration of the diester bond adjacent to the one undergoing hydrolysis. The anti-proliferative and anti-viral activities of these various phosphorothioate 2-5A core analogs were assessed. The most stable analogs possessed the greatest biological activities (at 25-50 microM), which were not readily attributable to 2-5A degradation products or endonuclease activation. A 5'-triphosphate analog of 2-5A containing a phosphorothioate substituent in the gamma-position was obtained in good yield by enzymatic synthesis from ATP-gamma S. This gamma-thio 2-5A analog showed full biological activity.

Enhanced efficacy of the acyclic nucleoside 9-(1,3-dihydroxy-2-propoxymethyl)guanine in combination with alpha-interferon against herpes simplex virus type 2 in mice.

The acyclic nucleoside DHPG [9-(1,3-dihydroxy-2-propoxymethyl)guanine] and recombinant human alpha-interferon of clones A/D potentiate each other's antiviral activity against a systemic infection with herpes simplex virus type 2. The effective dose at which 50% of the mice survived was lowered approximately 10-fold for DHPG when it was given in combination with a marginally effective dose of alpha-interferon and greater than 10-fold for alpha-interferon when it was given in combination with a nontherapeutic dose of DHPG.

Enhanced efficacy of the acyclic nucleoside 9-(1,3-dihydroxy-2-propoxymethyl)guanine in combination with beta-interferon against herpes simplex virus type 2 in mice.

The acyclic nucleoside 9-(1,3-dihydroxy-2- propoxymethyl )guanine (DHPG) and natural mouse interferon beta ( MuIFN -beta) were evaluated for their efficacy alone and in combination against herpes simplex virus type 2 systemic infections in mice. Intraperitoneally infected animals were treated once a day with the drugs at various concentrations for 5 days starting 24 h after inoculation. DHPG was injected subcutaneously at doses of 0.7 to 6 mg/kg. MuIFN -beta was given intraperitoneally at doses ranging from 3 X 10(3) to 3 X 10(4) IU per mouse. For DHPG alone, the effective dose at which 50% of the mice survived (ED50) was greater than 6 mg/kg. However, when given in combination with an ineffective dose of MuIFN -beta (10(4) IU per mouse), the ED50 for DHPG was 0.8 mg/kg. In addition, at the highest dose tested, MuIFN -beta alone had no protective activity against herpes simplex virus type 2 (ED50, greater than 3 X 10(4) IU per mouse). However, when given in combination with a marginally effective dose of DHPG (2 mg/kg), the ED50 for MuIFN -beta was less than 3 X 10(3) IU per mouse. Calculation of the fractional protective dose index (less than 0.23 where values of less than or equal to 0.5 are considered synergistic) indicates an enhanced protective interaction by the combination of the two drugs. These results represent the first time that potentiation of the antiviral activity of an acyclic nucleoside by interferon has been demonstrated in animal studies.