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A recombinant Eimeria protozoan protein antigen (rEA) has been shown to have antitumor and antiviral activity. The purpose of this study was to determine the effect of rEA treatment alone or in combination with an agonist cocktail consisting of granulocyte macrophage colony stimulating factor (GM-CSF), interferon gamma (IFN-γ), interleukin 4 (IL-4), and anti CD-40 antibody, in the treatment of Banzi virus (BV) disease in BALB/c mice. Treatment with rEA resulted in a significant increase in survival, weight gain, and mean day to death in BV-infected mice and resulted in a significant decrease in brain virus titer. Treatment with rEA, in combination with a 4-agonist cocktail, improved disease parameters to a greater degree than rEA treatment alone. The effect of treatment with a reduced concentration of agonist cocktail or fewer components of the agonist cocktail, in combination with rEA, on disease outcome in BV-infected mice was also investigated. Treatment with rEA, alone or in combination with agonist cocktail, 24 hours after virus challenge did not improve disease. Treatment with rEA, alone or in combination with an agonist cocktail, is efficacious for the prophylaxis of BV infection in mice.

Toll-like receptor (TLR) ligands are attractive adjuvant candidates in vaccine development. Eimeria tenella profilin-like protein has recently been shown to be a potent agonist of the innate immune system through its recognition by Toll-like receptor-11. In this report, we studied the systemic and mucosal adjuvant activity of Eimeria profilin-like protein within a vaccinal strategy against Toxoplasma gondii in mice. Using intraperitoneal (i.p.) immunization, we observed that coadministration of the recombinant Eimeria antigen (rEA) with T. gondii antigen (TAg) effectively elevates plasma levels of IL-12p70 and consequently induced both enhanced specific humoral and Th1 cellular immune responses. The co-administration of TAg plus rEA by i.p route significantly enhanced the protection against T. gondii infection (62% brain cyst reduction) in comparison with control mice and with mice immunized with TAg alone (only 36% brain cyst reduction). After intranasal immunization, humoral and cellular responses were weak. However mice immunized nasally with TAg plus rEA were significantly protected with 50% of brain cyst reduction, conversely TAg immunized mice did not present any brain cyst reduction.These results indicate that Eimeria profilin-like protein would serve as an efficacious systemic and mucosal adjuvant inducing protective immune response against chronical stage of T. gondii infection through TLR11 activation.

Recombinant Eimeria antigen (rEA) has been shown to have potent anticancer and antiviral activity in respective mouse disease models, presumably through robust immune stimulation that occurs via TLR11, a pattern recognition receptor that recognizes profilin-like proteins expressed on apicomplexan protozoans. Comparable immunostimulatory activity in other species has yet to be demonstrated. Since rEA is known to be highly effective in treating Punta Toro virus (PTV) infection in mice, its ability to elicit protective immunity in the hamster PTV infection model was investigated. rEA was given alone, or in combination with IL-18 or IL-2, and virally challenged hamsters were observed for mortality. Cytokine transcript profiles for IL-12p40, IL-21, IFN-gamma and TNF-alpha were assessed to evaluate the induction of these inflammatory mediators known to be induced in mice following exposure to rEA. A dose of 100 microg of rEA, given once 4 h prior to viral challenge, and a second time on day 3 of the infection, was found to be the most effective prophylactic therapy protecting 60% of treated hamsters from mortality, compared to only 5-10% observed in animals receiving placebo. Increased expression of IFN-gamma and IL-12p40 was evident following treatment with rEA. The data suggest that rEA does induce host antiviral responses in hamsters that result in significant protection from death, although determining the most appropriate dose for intervention in other species, including humans, will likely be challenging.

A protein antigen from an Eimeria protozoan has recently been reported to induce antitumor activity in mice. This activity most likely results from the strong induction of interkeukin-12 (IL-12) and gamma interferon (IFN-γ), which are also essential factors in the establishment of protective immunity against viral infection. We evaluated recombinant Eimeria antigen (rEA) as a potential immunotherapeutic agent in mouse and hamster models of acute phleboviral disease. Punta Toro virus (PTV) was highly sensitive to a single dose of nanogram quantities of rEA in the mouse infection model. Intraperitoneal treatment with rEA also reduced virus load and liver damage associated with PTV infection. IL-12 was elicited following exposure of uninfected mice to quantities of rEA of 10 ng or greater, and the levels peaked at between 3 and 8 h postexposure. IFN-γ release was induced more slowly and required less rEA (1 ng) to produce a significant rise in systemic levels. The induction of IL-12 and IFN-γ involved in the coordination of innate and adaptive immune responses to microbial pathogens required myeloid differentiation factor 88, a signaling adaptor shared by most members of the Toll-like receptor (TLR) family. Despite encouraging results in the murine system, rEA failed to protect hamsters challenged with PTV. Our findings suggest that hamsters may lack functional TLR11, which has recently been shown to recognize a profilin-like protein homologous to rEA from the protozoan Toxoplasma gondii . Further investigation into the immunostimulatory capacity of rEA in other mammalian systems is necessary.

The small intestine (SI) of vertebrates exhibits low tumorigenesis and rarely supports metastatic growth from distant tumors. Many theories have been proposed to address this phenomenon, but none has been consistently supported. One candidate mechanism is that the vast immunologic compartment of the SI provides a heightened level of tumor immunosurveillance. Consistent with this, we have identified a molecule of low abundance from bovine SI that has the hallmarks of a potent immunostimulant and may be associated with the natural suppression of cancer in the intestinal tract. The protein originates from an endemic gut protozoan, Eimeria spp., and is homologous to the antigen 3-1E previously isolated from the avian apicomplexan E. acervulina. We show here that it is a very potent stimulator of IL-12 release from dendritic cells, upregulates inflammatory modulators in vivo (IL-12, MCP-1, IL-6, TNF-alpha and INF-gamma) and has antitumor properties in mice. In addition, it is synergistic in vitro with anti-CD40 antibody, IFN-gamma, IL-4 and GM-CSF; is active across species barriers in vivo; and has no observable toxicity. Based on these activities, we speculate that it is an inducer of protozoan-targeted innate immunity, which may explain its potential benefit to the intestinal tract and potency as an agent in cancer immunotherapy.

Techniques from cancer epidemiology and time series analysis were used to explore the hypothesis that cosmic radiation can induce germ cell changes leading to increases in future breast cancer mortality. A birth cohort time series for female breast cancer mortality was obtained using a model-independent, age-period-cohort analysis on age-specific mortality data for 1940–1990. The birth cohort series contained several oscillatory components, which were isolated and compared to the corresponding frequency components of a cosmic ray surrogate time series – Greenland ice-core 10Be concentrations. A technique, referred to as component wave-train alignment, was used to show that the breast cancer and cosmic ray oscillations were phase-locked approx. 25 years before the time of birth. This is consistent with the time of germ cell formation, which occurs during the fetal development stage of the preceding generation. Evidence is presented that the observable oscillations in the birth cohort series were residues of oscillations of much larger amplitude in the germ cell cohort, which were attenuated by the effect of the broad maternal age distribution. It is predicted that a minimum of 50% of breast cancer risk is associated with germ cell damage by cosmic radiation (priming event), which leads to the development of individuals with a higher risk of breast cancer. It is proposed that the priming event, by preceding other steps of carcinogenesis, works in concert with risk factor exposure during life. The priming event is consistent with epigenetic changes such as imprinting.

Any thermodynamic study of aging and death in laboratory mammals is dependent on techniques which would allow for the chronic manipulation of the core body temperature of these organisms. Accordingly, the hypothermic response after parenteral administration of chlorpromazine, L-dopa, reserpine, and p -chlorophenylalanine was investigated in the mouse. Mice injected at 24 hour intervals with chlorpromazine exhibited a diminished response (tolerance) with repeated administration. The degree of induced hypothermia and resistance to tolerance was greater in male mice than in female mice. L-dopa was unable to potentiate chlorpromazine hypothermia but did evoke a non-adapting hypothermic response when administered alone. Reserpine also evoked a non-adapting hypothermia. Further, animals treated with small doses of reserpine exhibited an increasing response with repeated injections. p -Chlorophenylalanine induced hypothermy that became intermittent with successive administration. The results presented here indicate that both reserpine and L-dopa would be of value as hypothermic agents in long term investigations.

The preparation of Pt(NH3)2(MeU)2·2H2O, 1. [(NH3)2Pt(MeU)2Pt(NH3)2](NO3)2, 2. Pt(NH3)2Cl(MeU), 3. and (in solution) [Pt(NH3)2(OH)(MeU)], 4. (MeU = 1-methyluracil monoanion) is reported. Levels of l-methyluracil and 1–4 in platinum-l-methyluracil blue (PtMeUB) have been assessed by high performance liquid chromatography (HPLC). This technique has also been used to show that in physiological saline or water, PtMeUB hydrolyzes to 3 or 4, respectively. Visible spectroscopy shows that the rate of hydrolysis of PtMeUB is much faster in fetal calf serum than in saline or water, with HPLC indicating that the product of hydrolysis in serum is 3. The precipitate obtained upon treatment of DNA solutions with PtMeUB has also been shown to hydrolyze to 3 or 4 when suspended in saline or water. Compounds 1–3 have been tested against the Ascites S-180J tumors, with 2 and 3 being active, while 4 has been shown to react readily with DNA. Possible mechanisms of antitumor action of PtMeUB that involve 3 and 4 are proposed.

Some platinum coordination complexes are active anticancer drugs in animal and man. This new class of chemotherapeutics was discovered during the course of investigation of the electric field effect on bacterial growth. The platinum electrodes electrolyzed during the experiment, releasing a platinum complex which caused complete cessation of cell division in the bacterial rods. With this filamentation assay system, we were able to identify the specific chemical as cis-dichlorodiammineplatinum(II), a complex known since 1848. The bacterial studies with many such complexes suggested to us the generalizations that charged platinum complexes were bacteriocidal, while the neutral platinum complexes induced filamentation and, in lysogenic bacteria, lysis. The neutral complexes have ignificant activity against transplantable, virally induced, and chemically induced cancers in animals. They are synergistic with almost every other anticancer drug in current use. In man kidney toxicity is the dose limiting ...

When a solution containing the complex ion, [PtCl6]=, and NH4+ ions is irradiated, a photochemical change occurs in which the chloride ions of the ligand are sequentially replaced by 1, 2, or 3 ammonia molecules. The total charge on the complex ion decreases by 1 negative charge for each replacement. These changes can be followed by changes occurring in absorption spectra or in ionophoretic patterns. Each charged species of the complex has a unique effect on the bacteriological growth of Escherichia coli. The doubly negative species is a bacteriocide. The singly negative species appears to have little effect on either growth or cell division processes. The neutral species has little effect on growth, but markedly inhibits cell division processes, forcing filamentous growth. The cis and trans forms of the diamino complex, [PtCl4(NH3)2]0, have been synthesized. The absorption spectra of both have a λmax at 207 mµ. The electrophoretic patterns indicate predominantly neutral species in both cases. The trans form is relatively inefficient in inhibiting cell division, whereas the cis form is fully as efficient as the neutral species in inhibiting cell division. We identify the neutral species as the cis form of the complex.

Certain group VIIIB transition metal compounds were found to inhibit cell division in Escherichia coli , causing marked filamentous growth. Gram-negative bacilli were the most sensitive to this effect, whereas gram-positive bacilli responded only at near-toxic levels of the metal. None of the cocci tested showed any apparent effect. Cytokinesis (cross-septation) can be initiated by removal or decrease of platinum, but not by treatment with pantoyl lactone, divalent cations, or a temperature of 42 C.

Studies are reported on persistent internal polarization effects. This polarization can be produced, particularly in photoconductive, fluorescent substances of high dark resistance, by the action of various kinds of radiation in the presence of a dc electric field. It has been found that such polarizations, of more than 10 000 volts/cm, will persist for many days if kept in the dark after field removal. A material so polarized is in many ways a photosensitive electret. Among the substances tested, a [Zn: Cd]S phosphor and anthracene were used most extensively. Measurements are reported on the effect of ultraviolet, visible, and infrared light, gamma and beta rays on the production and removal of polarization. The increase of polarization with time is initially rapid and then shows saturation. It is almost a logarithmic function of the exciting radiation intensity, and a linear function of the polarizing voltage over a wide range. It is found that the equilibrium values of polarization are essentially determined by the applied voltage, and one parameter specific to the substance. Data are given on the long-time storage of polarization. It is shown that this polarization is due to a partial separation by the applied field of free mobile charges produced by the radiation inside the material and their localization in traps. It is not a charge injection-ejection phenomenon at the electrodes since it occurs just as well in samples insulated from the electrodes. In powders at least, the polarization is distributed throughout the entire sample and is not a charge accumulation near the surfaces. A correlation is established between these phenomena and the mechanism assumed for these substances to explain photoconductivity and fluorescence. A phenomenological model is presented which quantitatively describes many of the results of these experiments. This polarization effect provides a new method to detect and study energy storage in crystals.

Platinum-pyrimidine complexes have been used as the sole electron-dense stains for electron microscopy on 18 types of mammalian cells. These recently discovered complexes react avidly with nucleic acids in vitro, are antitumor agents, and are highly soluble in water. In cells, they are selective for regions rich in nucleic acid and make visible the cellular chromatin, nucleolus, and ribosomes. In addition, cells that are tumorigenic exhibit electron-dense patches at the plasma membrane; normal cells do not. The results of treatment of ascites sarcoma-180 cells with concanavalin A, nucleases, glycosidases, or a protease suggest that the electron-dense patches are DNA, with neuroaminic acid involved in the surface binding.

Publisher Summary Cisplatin (cis-dichlorodiammineplatinum II) is the first member of a new class of potent anticancer drugs, the metal coordination complexes, to enter general use in cancer chemotherapy. The drug has been proved to be effective alone or in combination for the treatment of a wide variety of solid cancers in man. Evidence suggests that it is curative for testicular cancers and ovarian cancers. It is also palliative in the treatment of cancers of the head and neck, bladder, prostate, lung, and cervix and in some pediatric cancers. The major toxic side effects of the drug are damage to the kidney, nausea, and vomiting. The hydration of the patient, with or without concomitant diuretics, ameliorates the kidney toxicity so well that in some clinical reports, it is no longer considered to be the dose-limiting side effect. The nausea and vomiting due to this drug are extreme, ubiquitous, and long lasting. Evidence has been reported indicating that nonstandard drugs such as marijuana, metaclopromide, and droperidol are effective in reducing the nausea and vomiting to an acceptable level.

Platinum coordination complexes form a new class of active anticancer agents in animals and man. Cis-dichlorodiammineplatinum(II), the most widely investigated drug, is now in experimental clinical use against a wide variety of cancers in man. The dose-limiting toxicity in man is renal tubular damage. Hydration of the patient and the use of osmotic diuretics have minimized this effect and allowed higher doses with largely improved responses. Combination chemotherapy with the drug has also produced significant response rates in a variety of cancers. The mode of action of the drug is not yet clear, but most likely involves a primary lesion on nuclear DNA and the stimulation of a host reaction to the cancer. So far, only square planar and octahedral complexes of platinum, with a variety of inorganic and organic ligands, have shown marked activity in animal studies.

The inhibitory effects of anti-tumor, bacterial filament forming platinum compounds, Cis-Pt(II) (NH3)2Cl2 (A), Cis-Pt(IV) (NH3)2Cl4 (B), and Pt(II) (NH2)2(CH2)2Cl2(C) on DNA, RNA and protein syntheses was measured by the incorporation of 3H-thymidine, 3H-uridine, and 3H-L-leucine, respectively, into an acid-insoluble polymer in human amnion AV3 cells. Compound A, the most effective tumor-inhibiting platinum compound, was shown to selectively inhibit DNA synthesis below 5μM and to inhibit 3H-thymidine incorporation more rapidly than 3H-uridine or 3H-leucine incorporation at 25μM. Like A, compounds B and C were also shown to inhibit all three processes after a 24-hour period of treatment at 25μM. A correlation was established between the relative anti-tumor effectiveness of compounds A, B, and C and the extent of their inhibitory effects. On the other hand, two non-tumor-inhibiting platinum compounds, [Pt(II) (NH3)4]Cl2 (D) and Trans-Pt(IV) (NH3)2Cl4 (E) had no inhibitory effects, except compound E, which exhibited a rapid initial inhibition of 3H-L-leucine incorporation at 100μM. The inhibition of 3H-thymidine incorporation into cells pretreated 4 h with 5μM of compounds A, B, and C was shown to be irreversible. Finally the inhibition of the incorporation of 3H-thymidine into DNA by A was shown not to be caused by the inhibition of the uptake of the tracer into the acid-soluble pool. A number of possible explanations for the greater sensitivity of DNA synthesis and the sequential inhibition of DNA, RNA and protein synthesis at higher concentrations are suggested.

The semiconduction and photoconduction currents through 1-ml thick sandwich cells of all-trans-, 13-cis-, 11-cis-retinal-, and 13-cis-retinal-m-nitroaniline-hydrogen chloride were measured as a function of the temperature in both the crystalline and melted states. From the slopes of graphs of the log of the current against 1000/TGK, the activation energies for semiconduction and photoconduction were calculated using the conductivity equations for the band model. The results of the average semiconduction activation energy measurements fell into two categories: The first group has activation energies between 1.9 and 2.4 eV and includes crystalline all-trans-, 13-cis-,9cis-retinal, and both crystalline and melted 13-cis-retinal-m-nitroanaline hydrogen chloride; the second group has activation energies between 3.1 and 3.6 eV and includes crystalline 11-cis-retinal samples shorted. The average photoconduction activation energy for crysalline 13-cis- and 11-cis-retinal, being 0.25 and 0.24 eV respectively, were essentially identical within experimental error, whereas the same parameter for 13-cis-retinal-m-nitroaniline hydrogen chloride was considerably lower at 0.15 eV. All-trans-retinal was not measurably photoconductive and 9-cis-retinal was only slightly photoconductive.

CERTAIN platinum compounds completely but reversibly iiihibit cell division in Gram-negative rods1–4. These compounds have been tested for antitumour activity and we report some of the preliminary results. The platinum compounds inhibit sarcoma 180 and leukaemia L1210 in mice.