Photoinduced antitumour effect of hypericin can be enhanced by fractionated dosing

The in vivo antitumour activity of the natural photosensitizer hypericin was evaluated. C3H/DiSn mice were inoculated with fibrosarcoma G5:1:13 cells. When the tumour reached a volume of 40-80mm3 the mice were intraperitoneally injected with hypericin, either in a single dose (5mg/kg; 1 or 6h before laser irradiation) or two fractionated doses (2.5 mg/kg; 6 and 1 h before irradiation with laser light; 532 nm, 70mW/cm2, 168 J/cm2). All tumours in control groups treated with hypericin alone as well as those irradiated with laser light alone had similar growth rates and none of these tumours regressed spontaneously. Complete remission of tumour in photodynamic therapy (PDT)-treated groups was similar (14-17% single dose vs. 33% fractionated dose), but the fractionated schedule of hypericin dosing was found to be more efficient than the single dose, measured by survival assay (p < 0.05). Our experimental model showed that fractionated administration of hypericin can produce a better therapeutic response than single administration.     

Histomorphological changes in murine fibrosarcoma after hypericin-based photodynamic therapy

Histomorphological changes in murine fibrosarcoma after photodynamic therapy (PDT) based on the natural photosensitizer hypericin were evaluated. C3H/DiSn mice were inoculated with fibrosarcoma G5:1:13 cells. When the tumour reached a volume of 40-80 mm(3) the mice were intraperitoneally injected with hypericin, either in a single dose (5 mg/kg; 1 or 6 h before laser irradiation) or two fractionated doses (2.5 mg/kg; 6 and 1 h before irradiation with laser light; 532 nm, 70 mW/cm(2), 168 J/cm(2)). All groups of PDT-treated animals with single and fractionated hypericin dosing presented primary vascular reactions including vascular dilatation, congestion, thrombosis and oedema. Two hours after PDT there were necrotic changes with small, rather focal appearance. One day after therapy the necrotic areas were enhanced, often affecting a complete superficial layer of tumour tissue. Necrotic areas were accompanied with inflammation and haemorrhages.     

Increased survival of normal cells during laser photodynamic therapy: implications for ex vivo autologous bone marrow purging

Laser light-induced, dye-mediated photolysis of leukemic cells was tested in an in vitro model for its efficacy in eliminating occult tumor cells for ex vivo autologous bone marrow purging. Merocyanine 540 (MC540) was mixed with acute promyelocytic leukemia (HL-60) cells in the presence of human albumin. This cell-dye mixture was irradiated with 514 nm argon laser light. Results show that in the presence of 0.1%, 0.25% and 0.5% albumin, laser light doses of 62.4 J/cm2, 93.6 J/cm2 and 109.2 J/cm2, respectively, were required for a 5 log reduction in the survival of leukemic cells. Under identical conditions, 80% to 84% of the normal bone marrow cells and 41% of the granulocyte-macrophage colony forming cells survived. The number of surviving stromal cells was reduced (1+) compared to the untreated control (4+). Mixing of irradiated bone marrow cells with equal number of HL-60 cells did not interfere with the killing of HL-60 cells treated with MC540 and laser light. The non-specific cytotoxicity of laser light alone was less than 6% for normal bone marrow cells. These results suggest that the concentration of human albumin plays an important role in laser light-induced phototoxicity. This laser light-induced selective photolysis of leukemic cells can be used in ex vivo purging of tumor cell-contaminated bone marrow grafts to achieve very high survival rates of normal bone marrow cells and granulocyte-macrophage colony forming cells.     

Administration of recombinant human IL11 after supralethal radiation exposure promotes survival in mice: interactive effect with thrombopoietin

In the present study, we evaluated the therapeutic potential of recombinant human IL11 in lethally irradiated C57BL6/J mice exposed to gamma rays. IL11 administered for 5 consecutive days beginning 2 h after total-body irradiation with 8 or 9 Gy 60Co gamma rays resulted in a significant increase in 30-day survival. When IL11 was administered, only a slight improvement in the hematopoietic status (both blood cell counts and progenitor cells) was observed after an 8-Gy exposure, and no improvement in hematopoietic reconstitution was observed after 9 Gy total-body irradiation. The enhancement of fibrinogen in the plasma of irradiated animals suggested the importance of infections in the death of animals. IL11 was able to limit the increase in fibrinogen levels. However, prevention of bacterial infections by antibiotic treatment, although it delayed death, was ineffective in promoting survival either in placebo-treated and IL11-treated mice. IL11 was administered along with thrombopoietin (TPO) or bone marrow transplantation to limit the hematopoietic syndrome, in addition to antibiotic treatment. When IL11 was combined with TPO, a potent stimulator of hematopoiesis, the survival of animals which had been irradiated with 10 Gy 137Cs gamma rays was increased significantly compared to those treated with IL11 or TPO alone. Furthermore, an interactive effect of TPO and IL11 on hematopoietic reconstitution was observed. Similarly, IL11 in combination with bone marrow transplantation enhanced survival after 15 Gy 137Cs gamma rays. These data suggest that the effect of IL11 on the hematopoietic system is only moderate when it is used alone in supralethally irradiated mice but that the effect is improved in the presence of a hematopoietic growth factor or bone marrow transplantation.     

Antineoplastic effects of carnosine and beta-alanine--physiological considerations of its antineoplastic effects

Antineoplastic effects of carnosine (CAR) and beta-alanine (ALA), were examined in vivo using ddY mice implanted with the solid tumor Sarcoma-180. The sarcoma was treated with trypsin, 10(5) cells were implanted subcutaneously in the back of the animals, and CAR and ALA were administered subcutaneously 2 cm from the implantation site starting on the next day. The animals treated with ALA alone showed prolongation of survival to a T/C value of 132%; the growth of the tumor was inhibited and mortality reduced in those treated with CAR alone. Regression of the tumor was observed in the animals treated with either drug. The effects of these agents were enhanced when administered in combination with the non-specific active immuno-enhancing agent OK-432. More than half the animals treated with CAR and OK-432 survived the observation period (T/C greater than 218%), and survival was prolonged in those treated with ALA and OK-432 to a T/C value of 132%. The agents also showed potent antineoplastic effects on Sarcoma-180 when the tumor had been attenuated in vivo with mitomycin C (MMC).     

Photosensitive chemical and laser light treatments decrease epizootic hemorrhagic disease virus associated with in vitro produced bovine embryos

Photoinactivation was employed to eliminate EHDV-2 from in vitro produced bovine embryos experimentally exposed to this virus. Immature oocytes were matured, fertilized, and cultured in chemically defined conditions. All treatments were performed on zygotes. Developmental potential of zygotes and cell numbers of resulting hatched blastocysts were assessed after exposure to a 1 mW helium neon laser (633 nm, red) for 1, 5, 10, and 15 min; the photosensitive chemicals hematoporphyrin (15 microM) and hypericin (1 and 10 microM) for 15 min; a combination of 10 microM hypericin and laser light for 1, 3, or 5 min; and a combination of 15 microM hematoporphyrin and laser light for 1, 2, or 3 min. There were no significant differences among proportions of embryos developing or cell numbers after treatment with or without exposure to laser light alone for up to 10 min. No differences were observed after exposure of zygotes to photosensitive chemicals alone. Exposure to 10 microM hypericin and 5 min of laser light or 15 microM hematoporphyrin and 2 min of laser light compromised zygote developmental potential. After exposure to 10(6) TCID50/mL EHDV-2 for 90 min groups of 10 zygotes were exposed to 10 microM hypericin or 15 microM hematoporphyrin and laser light to inactivate the virus. Hematoporphyrin was effective with 3 min light exposure at reducing the percentage of EHDV-2 contaminated zygote pools (16.7%) as compared to EHDV-2 exposed pools without treatment (88.9%) but hematoporphyrin + 1 min light was ineffective. Hypericin + 3 min light provided an intermediate effect (55.6%).     

Immunomodulatory screening test of corn oil administered orally to female mice: effect of timing of dosing within 24 hours

The effect of varying the dose-delivery time within a 24 h period (12:12 light-dark cycle) on the immunomodulatory properties of corn oil administered by gavage to 120 B6C3F1 female mice was investigated. Mice, housed in six separate boxes equipped with timers to regulate light onset and offset (staggered by 4 h increments), were treated for 5 consecutive days by intragastric (i.g.), administration of 5 mL/kg corn oil. Negative and positive control mice were given sham injections (needle inserted, but no injection). Sheep red blood cells (SRBCs) were injected intraperitoneally (i.p.) on the fifth day. Three days later, positive control mice were given cyclophosphamide intraperitoneally (80 mg/kg). Four days after SRBC injection, mice were weighed and killed, and spleens and thymuses were removed and weighed. Spleens were brought to single-cell suspensions and tested for an antibody response to the SRBC. Plaque-forming cells (PFCs), as measured per spleen, per 10(6) viable spleen cells or per 10(6) total spleen cells, exhibited significant circadian rhythms for mice given corn oil, but not for sham-gavage- and cyclophosphamide-treated mice. The peak response (acrophase, phi) occurred at 21 h, 22 h, and 23 h after lights on (HALO), respectively, with PFC values significantly different between the different time points. Corn oil and sham gavage affected the circadian pattern of antibody production; there was a high-amplitude (21-27%) rhythm observed when mice were treated with corn oil and no rhythm when mice received the sham-gavage treatment. In addition to testing mice near the end of the daily dark span and/or early light span to obtain a maximum immune response, this finding points to the importance of including as controls a group of animals that are not treated at all and a group given vehicle alone, rather than only sham-treated animals, for comparison with experimentally treated animals.     

Effects of transcranial laser irradiation in near infrared range on antinociceptive reactions in mice after administration of diazepam, clopheline and morphine]

The experiments were carried out on white mice whose brain was irradiated transcranially with laser light in infrared range. Exposure to irradiation was 20 min. In one group of animals only laser light was used, in others laser was combined with morphine (3mg/kg), clonidine (0.5 mg/kg), and diazepam (1 mg/kg) injected intraperitoneally. The nociceptive reactions were studied with the help of "tail-flick" and "hot-plate" tests. It was found that laser light did not modify significantly the results of both tests. Moreover, it didn't influence the antinociceptive properties of morphine, clonidine and diazepam in the "hot-plate" test. In the "tail-flick" test laser light did not affect the action of clonidine, but provided naloxone-independent antinociceptive reaction with diazepam and increased the antinociceptive effect of morphine. Laser irradiation of the brain did not cause any significant morphological changes. These results suggest the possibility of modulating antinociceptive actions of morphine and diazepam by laser irradiation of the brain.     

Microwave treatment of intracerebral l1210 leukemia: Schedule-dependent partial reversal of the effects of methotrexate

One-GHz microwave (MW) irradiation at a power density of 5 mW/cm² was combined with methotrexate (MTX) in an attempt to treat more effectively central nervous system (CNS) L1210 leukemia in DBA/2J mice. When mice with CNS leukemia were treated with the combination of MW and MTX, there was no improvement in survival compared with a group of animals treated with MTX alone; however, the group that received MTX before the MW exposure had a significantly reduced survival time compared with the group treated with MTX alone or with the group to which MTX was administered after MW.     

Increased efficiency of immunotherapy using irradiated tumor cells

Summary The efficacy of irradiated tumor cells combined with chemotherapy or non-specific immunostimulation with complete Freund's adjuvant was tested in a model of minimal residual tumor-bearing syngeneic mice. Male C57BL/6J mice were innoculated in the right rear leg with live tumor cells from a methylcholanthrene induced fibrosarcoma. The tumor was resected when it reached 0.7 cm in diameter and animals were treated with doses of irradiated tumor cells (XTC) from the primary tumor ranging in number from 1×10³ to 9×10³. Best survival was noted using 5×10³ XTC combined with irradiated tumor cells of liver or pulmonary metastases origin, complete Freund's adjuvant or cytoxan. The combination of irradiated tumor cells of metastatic origin did not enhance the therapeutic effect of XTC alone. Freund's adjuvant was not of benefit in enhancing the efficacy of XTC. However, improved survival was noted when chemotherapy in the form of cytoxan was used to supplement XTC. Our data suggests that XTC is more efficacious as a mode of immunotherapy than are live tumor cells. The dose of XTC used is critical in determining its effect. Chemotherapy appears to enhance the benefit of XTC.Research fellow from Zhejiang Medical University, Hongzhou, ChinaSupported by the Brigham Surgical Group, Inc.     

Action of lincomycin, chymotrypsin and their combinations on the course of experimental staphylococcal infection

The culture of Staphylococcus aureus was administered intraperitoneally in a dose of LD30 to albino mice. The animals of the 1st, 2nd and 3rd groups were treated with lincomycin, chymotripsin and combination of lincomycin with chymotripsin respectively. The animals of the 4th group were used as control and were not subjected to the treatment with the drugs. A part of the animals from every group was killed on the 3rd, 7th, 14th, 21st and subsequent days and their organs were investigated microscopically and bacteriologically. It was found that staphylococci was isolated from the control mice during a 50-day period after inoculation. Complete liberation of the organs from the causative agent within 25 days from the beginning of the experiment was registered in the animals treated with lincomycin. Isolation of the staphylococci was over by the 27th day in the animals treated with chymotrypsin. Liberation of the organs from the causative agent by the 17th day was observed in the albino mice treated with the combination of lincomycin with chymotrypsin. The combined use of lincomycin with chymotrypsin proved to be most effective: no death was registered among the albino mice, the levels of the pathogenicity and antibiotic resistance in the pathogenic staphylococci decreased.     

Effect of metronidazole on the free thymidine content in the blood serum of irradiated mice

The influence of a radiosensitizer, metronidazole, on the free thymidine content of blood serum of irradiated mice was studied in aerobic and hypoxic conditions. A heated metronidazole solution (1 mg/g) was administered intraperitoneally 30 min before irradiation of animals with a dose of 3 Gy. Thymidine concentration in blood serum was determined by the radioimmunological technique. The influence of metronidazole on the level of thymidinemia was only noted in the animals exposed under hypoxic conditions.     

He—Ne激光照射离体鼠巨噬细胞对线粒体跨膜电势的影响

目的：研究Ｈｅ－Ｎｅ激光照射鼠巨噬细胞对线粒体跨膜电势的影响,及其与激光剂量的关系。方法：用亲脂性阳离子荧光染料Ｒｈｏｄａｍｉｎｅ１２３对鼠巨噬细胞线粒体作荧光标记,以不同的激光剂量照射,采用图像分析系统（ＩＡＳ）和荧光显微镜观察线粒体跨膜电势荧光强度的变化。结果：低功率Ｈｅ－Ｎｅ激光照射５,１０,１５ｍｉｎ,激光剂量分别为０．６４９,１．３８８和２．０８２Ｊ／ｃｍ＾２,巨噬细胞线粒体跨膜电势荧光     

Melatonin and protection from whole-body irradiation: survival studies in mice

The radioprotective ability of melatonin was investigated in mice exposed to an acute whole-body gamma radiation dose of 815 cGy (estimated LD50/30 dose). The animals were observed for mortality over a period of 30 days following irradiation. The results indicated 100% survival for unirradiated and untreated control mice, and for mice treated with melatonin or solvent alone. Forty-five percent of mice exposed to 815 cGy radiation alone, and 50% of mice pretreated with solvent and irradiated with 815 cGy were alive at the end of 30 days. Irradiated mice which were pretreated with 125 mg/kg melatonin exhibited a slight increase in their survival (60%) (p=0.3421). In contrast, 85% of irradiated mice which were pretreated with 250 mg/kg melatonin were alive at the end of 30 days (p=0.0080). These results indicate that melatonin (at a dose as high as 250 mg/kg) is non-toxic, and that high doses of melatonin are effective in protecting mice from lethal effects of acute whole-body irradiation.     

Combination Efficacy of Voriconazole and Amphotericin B in the Experimental Disease in Immunodeficient Mice Caused by Fluconazole-resistant <Emphasis Type="Italic">Cryptococcus neoformans</Emphasis>

The therapeutic efficacy of amphotericin B and voriconazole alone and in combination with one another were evaluated in immunodeficient mice (BALB/c-SCID) infected with a fluconazole-resistant strain of Cryptococcus neoformans var. grubii. The animals were infected intravenously with 3 × 10⁵ cells and intraperitoneally treated with amphotericin B (1.5 mg/kg/day) in combination with voriconazole (40 mg/kg/days). Treatment began 1 day after inoculation and continued for 7 and 15 days post-inoculation. The treatments were evaluated by survival curves and yeast quantification (CFUs) in brain and lung tissues. Treatments for 15 days significantly promoted the survival of the animals compared to the control groups. Our results indicated that amphotericin B was effective in assuring longest-term survival of infected animals, but these animals still harbored the highest CFU of C. neoformans in lungs and brain at the end of the experiment. Voriconazole was not as effective alone, but in combination with amphotericin B, it prolonged survival for the second-longest time period and provided the lowest colonization of target organs by the fungus. None of the treatments were effective in complete eradication of the fungus in mice lungs and brain at the end of the experiment.     

Interleukin 4 promotes survival of lethally irradiated mice in the absence of hematopoietic efficacy

The therapeutic potential of Il4 in lethally irradiated mice was evaluated in C57BL6/J mice subjected to 7 to 10 Gy total-body irradiation (TBI) from a (60)Co gamma-ray source. Il4 was administered 2 h after TBI either in a single injection or for 5 consecutive days. Il4 treatment increased 30-day survival of mice irradiated with doses as high as 8.5 Gy, which caused 100% mortality in placebo-treated animals. By convention, hematopoietic failure would induce death over a period of up to 30 days. However, in our study, the Il4-enhanced survival of mice within this period could not be attributed to significantly accelerated hematopoietic reconstitution as shown by blood cell counts and progenitor cell contents in the bone marrow and spleen. Our data strongly suggest that aplasia is not the only cause of death of animals irradiated with doses around the LD(50) and that Il4-treated animals can survive in spite of a very poor hematopoietic activity.     

Triple therapy with octreotide,galanin and serotonin induces necrosis and increases apoptosis of a rat colon carcinoma

A rat colonic adenocarcinoma was implanted subcutaneously (s.c.) in nude mice. After 7 days, the animals were divided into different groups. Two groups received subcutaneous injections twice daily with 3 or 6 micro g/kg body weight octreotide, galanin and serotonin. Three groups were respectively treated with 20, 30, and 40 micro g/kg body weight of the previously mentioned bioactive substances. Control group received only saline solution in the same fashion as treated animals. The treatment lasted for 5 days. The tumour volume and weight, the relative density of blood vessels, of tumour necrotic tissue, of apoptotic nuclei and of proliferating nuclei were measured. Apoptosis was detected by in situ labelling of nuclear DNA fragmentation according to TUNEL method, and proliferation by immunocytochemistry. Morphometry was done with the classical stereological point-counting method. Food consumption, animal weight, faeces weight and its water content were measured for 3 days before and after treatment. Triple therapy with 3 and 6 micro g/kg body weight had no effect on any of the parameters measured, except in reducing the relative volume density of tumour blood vessels. Treatment with 20, 30 and 40 micro g/kg body weight of the previously mentioned bioactive substances reduced the tumour volume, the relative volume density of blood vessels and increased the relative volume density of necrotic tissue and of apoptotic nuclei (in the 20 micro g group). However, there was no difference between treated mice and controls regarding the relative volume density of proliferating nuclei. There was no statistical difference between treated animals regarding food consumption, body weight, faeces weight and its water content before and during treatment. The present study confirms that triple therapy with octreotide, galanin and serotonin causes regression of a rat colon carcinoma. It further showed that optimum treatment dose is 20 micro g/kg body weight of each bioactive substance. Moreover, this therapy regime does not show apparent side effects in the experiments carried out on mice.     

Comparative study of four antifungal drugs in an experimental model of murine cryptococcosis

A comparative study among amphotericin B, 5-fluorocytosine, itraconazole and fluconazole in the treatment of experimental cryptococcosis in mice, was carried out.Seventy male Balb C mice were inoculated intraperitoneally with 10⁷ cells of Cryptococcus neoformans var. neoformans. They were divided in 7 groups of 10 animals each one: 1) treated with fluconazole by gavage at a daily dose of 16 mg/kg; 2) treated with itraconazole by gavage at a daily dose of 16 mg/kg; 3) treated with 5-fluorocytosine by gavage at a daily dose of 300 mg/kg; 4) treated with amphotericin B intraperitoneally at a dose of 6 mg/kg every other day; 5) control animals receiving polietilenglicol 200 by gavage; 6) control animals receiving distilled water by gavage and 7) control animals receiving sterile distilled water by intraperitoneal route. All the treatments started 5 days after the challenge inoculation and they were given for 2 weeks.The following parameters were taken into account: survival time, macroscopic aspect of the organ after the complete autopsy, microscopic investigation of yeasts in brain, lungs, spleen and liver, histopathology studies of these organs, the colony forming units per gram and massive seeding of brain and lungs.The survival index of the different groups was the most efficient method to measure the antifungal compounds activity. Amphotericin B increased significantly the animals survival and modified the histopathologic response in the studied organs. The colony forming units and the massive seeding in brain and lung showed that this antifungal agent is unable of producing the biological cure of this experimental model.The remaining drugs assayed did not promote important modifications in the histopathologic picture as well as in the tissues cultures. However, the three drugs increased the animals survival. In this aspect, fluconazole proved to be slightly superior.     

Cellular inactivation and antitumor efficacy of a new zinc phthalocyanine with potential use in photodynamic therapy

The aim of the present study was to evaluate the photodynamic efficacy of a novel phthalocyanine derivate 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylamino) ethylsulfanyl]phthalocyaninatozinc(II) (referred here as S1) using MCF-7c3 human breast cancer cells and the LM2 adenocarcinoma subcutaneously implanted in Balb/c mice as experimental models. The S1-l-alpha-dimyristoyl-phosphatidylcholine liposome was selected as the best delivery system because it showed greater internalization into cells (35 nmol/10(6) cells), relative to other liposomes. After 3 h incubation S1 was partially localized in lysosomes, the compartment that represented its primary photodamage site. The S1 treated cultures also revealed a degree of mitochondrial morphology alteration. Indeed, S1 leads to photokilling of the cells with different efficacies indicating that cell photoinactivation was dependent on both the phthalocyanine concentration and the light dose applied. Analyses of morphology and nuclear condensation level indicated that some of the cells exposed to photodynamic therapy were undergoing apoptosis within 8h after treatment. To assess the in vivo effectiveness of S1, animals bearing tumors were treated with 0.2mg/kg S1 followed 24h later by 108 J cm(-2) light at 600-800 nm and 60 mW cm(-2),while other animals served as controls (no treatment, light alone, or S1 alone). All S1 treated tumors and none of the controls exhibited complete or partial responses, and these responses continued for the entire observation period of 12 days. Evaluation of tumor size showed that the treatment effectively delayed tumor growth. Light microscopy investigations of irradiated tumor specimens showed that S1 causes an early direct damage of malignant cells, largely via processes leading to random necrotic pathways.