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At least 973 records · Page 54Linked to original sources
PubMed2006

PVP magnetic nanospheres: biocompatibility, in vitro and in vivo bleomycin release.

PURPOSE: To synthesize and characterize a magnetic micromolecular delivery system based on PVP hydrogel with polyvinyl alcohol (PVA) as the crosslinker. METHODS: The microparticles were successfully prepared using 25 kGy Co-60 gamma-ray irradiation and characterized. Biocompatibility, in vitro and in vivo drug release tests were carried out. RESULTS AND DISCUSSION: Bleomycin was quantitatively released with in slightly over 8 h (hours) from the nanospheres containing 1mg bleomycin while the time was longer for those containing 5 mg. On the other hand free bleomycin quantitatively passed through the dialysis baffle with in only 3.5 h. For both 5 and 1 mg of bound bleomycin, it took up to 2 h to reach peak concentration compared to 30 min for the free drug. CONCLUSION: The PVP hydrogel magnetic nanospheres exhibited passive drug release that could be exploited to enhance therapeutic efficacy. The present results indicate that PVP hydrogel based magnetic nanospheres have potential as drug carriers in magnetic guided chemotherapeutic drug delivery.

Animals↗
PubMed2006

Novel ultra-deformable vesicles entrapped with bleomycin and enhanced to penetrate rat skin.

Beta-sitosterol 3-beta-D-glucoside (Sit-G), an absorption enhancer, was incorporated into ultra-deformable vesicles containing bleomycin to attenuate drug toxicity in human keratinocytes. The presence of Sit-G increased drug entrapment and improved in vitro stability of ultra-deformable vesicles. Confocal laser scanning microscopy revealed the extent to which Sit-G facilitated the penetration of ultra-deformable vesicles containing fluorescent probes into rat skin upon non-occlusive topical application. Furthermore, treatment with preparations incorporating Sit-G resulted in elevated epidermal and dermal concentrations of bleomycin. Ultra-deformable formulation contained Sit-G maintained flexibility for penetration through the skin, increased entrapment efficiency of bleomycin and stability in vitro, and significantly increased distribution of bleomycin in epidermis and dermis compared with those without Sit-G.

Animals↗
PubMed2004

Inhibition of key cytokines by tetrathiomolybdate in the bleomycin model of pulmonary fibrosis.

Tetrathiomolybdate is an anticopper drug with a unique mechanism of action. Tetrathiomolybdate complexes copper to protein and itself, rendering the copper unavailable for cellular uptake. It was originally developed for Wilson's disease, and is now being developed as an antiangiogenic agent for the treatment of cancer. Many angiogenic cytokines require normal levels of copper, and lowered copper levels reduce cytokine signaling while cellular copper requirements are met. Cytokines of fibrosis and inflammation may be similarly copper dependent, since tetrathiomolybdate inhibits bleomycin induced pulmonary inflammation and fibrosis. The basis for this inhibition was evaluated here by examination of tetrathiomolybdate effects on cytokines in lung pathophysiologically important in the bleomycin mouse model of pulmonary damage. Results in mice injected endotracheally with bleomycin confirmed that tetrathiomolybdate therapy was effective in reducing fibrosis. This effect was associated with significant inhibition of bleomycin-induced tumor necrosis factor alpha and transforming growth factor beta expression in lung homogenates. These effects were shown to be independent of one another. This indicates that tetrathiomolybdate therapy can be effective even when fibrosis is at a more chronic stage, wherein inflammatory cytokines are playing a diminishing role. The inhibition of tumor necrosis factor alpha suggests that diseases of tumor necrosis factor alpha overexpression are also potential targets of tetrathiomolybdate therapy.

Administration, Oral↗
PubMed2006

Efficient repair of bleomycin-induced double-strand breaks in barley ribosomal genes.

Ability of barley ribosomal genes to cope with damage produced in vivo by the radiomimetic agent bleomycin was investigated. Repair kinetics of bleomycin-induced double-strand breaks in ribosomal and total genomic DNA was compared. Induction and repair of double-strand breaks in defined regions of the ribosomal genes was also analyzed. Preferential sensitivity of barley linker DNA towards bleomycin treatment in vivo was established. Relatively higher yield of initially induced double-strand breaks in genomic DNA in comparison to ribosomal DNA was also found. Fragments containing intergenic spacers of barley rRNA genes displayed higher sensitivity to bleomycin than the coding sequences. No heterogeneity in the repair of DSB between transcribed and non-transcribed regions of ribosomal genes was detected. Data indicate that DSB repair in barley rDNA, although more efficient than in genomic DNA, does not correlate with the activity of nucleolus organizer regions.

Bleomycin↗
PubMed2004

IL-10 inhibits inflammation but does not affect fibrosis in the pulmonary response to bleomycin.

Bleomycin yields pulmonary injury characterized by inflammation that proceeds to fibrosis. The production of IL-10 by pulmonary macrophages is increased in the inflammation that accompanies bleomycin lung injury. In the present study, IL-10 deficient and wildtype mice received 0.075 units of bleomycin intratracheally at day 0 and were sacrificed at day 7 or day 14. At day 7, pulmonary inflammation was increased in IL-10-deficient mice as reflected by increased representation of CD3+ and CD4+ lymphocytes and GR-1+ pulmonary granulocytes in the bronchoalveolar lavage (BAL) fluid. Pulmonary interstitial CD80+ and CD86+ mononuclear cells were increased in situ. At day 14, mononuclear cell inflammation was comparable between groups but pulmonary eosinophils were increased in the wildtype. There was no difference in the degree of pulmonary fibrosis, as judged by histology or lung hydroxyproline content. Lung chemokine expression of MIP-1alpha/beta, MIP-2, and eotaxin was increased at days 7 and 14 with a trend towards increased MCP-1 expression at day 14. The findings suggest an immunomodulatory role for IL-10 in the inflammatory response but not in the pulmonary fibrosis yielded by bleomycin.

Animals↗
PubMed2004

Increase in p21 expression independent of the p53 pathway in bleomycin-induced lung fibrosis.

Although a number of animal models have been used to study the pathogenesis of lung disease, to date few studies have looked at changed in the expression of cell cycle regulatory genes. We have studied the variation in the expression of p21, p53, p27 and PCNA in bleomycin-induced lung fibrosis using animal mouse models using immuno-histochemistry and gene-expression analysis. No difference in the p53, PCNA and p27 expressions were observed from the bleomycin-induced fibrosis when compared to saline-induced non-fibrotic lungs. Although no difference in nuclear p21 expression was observed, the level of cytoplasmic p21 expression was found to be higher in fibrotic lungs at day 14 after bleomycin injection. p21 expression was found to increase independent of p53 in fibrotic lungs at 14 days after bleomycin induction.

Animals↗
PubMed2005

Gender-based differences in bleomycin-induced pulmonary fibrosis.

The role of gender and sex hormones is unclear in host response to lung injury, inflammation, and fibrosis. To examine gender influence on pulmonary fibrosis, male and female rats were given endotracheal injections of either saline or bleomycin. Female rats showed higher mortality rates and more severe fibrosis than did male rats, as indicated by higher levels of lung collagen deposition and fibrogenic cytokine expression. To clarify the potential role of female sex hormones in lung fibrosis, female rats were ovariectomized and treated with either estradiol or vehicle plus endotracheal injections of either saline or bleomycin. The results showed diminished fibrosis in the ovariectomized, bleomycin-treated rats without hormone replacement. Estradiol replacement restored the fibrotic response to that of the intact female mice in terms of lung collagen deposition and cytokine expression, which was accompanied by higher plasma estradiol levels. Furthermore, fibroblasts from bleomycin-treated rats exhibited increased responsiveness to estradiol treatment, causing dose-dependent increases in procollagen 1 and transforming growth factor-beta1 mRNA expression relative to untreated controls. Taken together these findings suggest that female mice may have an exaggerated response to lung injury relative to male mice because of female sex hormones, which have direct fibrogenic activity on lung fibroblasts. This may provide a mechanism for a hormonally mediated intensification of pulmonary fibrosis.

Animals↗
PubMed1999

The role of p53 in bleomycin-induced DNA damage in the lung. A comparative study with the small intestine.

To elucidate the role of p53 and apoptosis in the pathogenesis of lung injury, we examined histological changes, expressions of p53 and p21waf1/cip1 (p21), apoptosis, DNA double strand breaks, cell kinetics, and DNA synthesis in C57/BL6 mice (p53+/+) and mice deficient for p53 (p53-/-) at 2 hours to 7 days after a single intravenous administration of bleomycin. We also compared these parameters between the lung cells and small intestinal epithelial cells to explore potential differences in their response to DNA damage. Bleomycin induced p21 expression in a p53-dependent manner in p53+/+ mice but neither p53 nor p21 expression in p53-/- mice. In the lung of both groups of mice, focal inflammation followed by fibrosis was observed, but there was no evidence of apoptosis. Cells with DNA breaks and those undergoing DNA synthesis were unequivocally increased, but the cycling cell fraction remained unchanged, suggesting that the DNA synthesis detected in the lung reflected unscheduled DNA synthesis for repair of damaged DNA. DNA breaks and unscheduled DNA synthesis were prolonged in p53-/- mice compared to p53+/+ mice. By contrast, in the small intestine, marked cell cycle arrest and extensive apoptosis were evoked in the cycling crypt cells of both groups of mice, but these changes were milder and DNA breaks remained detectable for a longer time in p53-/- mice than in p53+/+ mice. Among the resting enterocytes in the villi, apoptosis was observed almost equally in both groups, but repair of DNA breaks was significantly delayed in the p53-/- mice. These observations imply that apoptosis is mediated largely by the p53-dependent pathway in the crypts but exclusively by the p53-independent pathway in the villi, that this pathway is particularly important in DNA repair in the villi, and that despite this difference in the significance of apoptosis, p53 plays an important role in DNA repair in both the crypts and villi. Our results suggest that the lung cells and small intestinal cells respond to the bleomycin treatment in different ways in terms of the induction of apoptosis and that p53 carries out an essential role in the early response to and repair of DNA damage by a non-apoptotic mechanism which appears to be crucial in the noncycling lung cells and enterocytes. Importantly, the p53-p21 pathway and apoptosis are unlikely to be essential for bleomycin-induced tissue injury in the lung.

Animals↗
PubMed1977

Combined therapy of oral cancer bleomycin and radiation: a clinical trial.

A concurrent randomised controlled clinical trial to evaluate a combination of Bleomycin and radiation as against radiation only in the treatment of advanced oral cancer has been conducted at the Cancer Institute, Madras, since 1971. All T3 and T4 previously untreated oral squamous cell carcinomas with N0, N1 and N2 regional nodes, or N3 nodes confined to the submandibular region, without systemic metastases or gross infiltration of the temporal and infratemporal fossa producing total trismus, and in decent general health were eligible for the trial. Patients with gross active pulmonary tuberculosis were excluded, as were recurrent carcinomas. Age, external fungation of growth or radiological bone invasion were no bar. Randomisation was done by the sealed envelope technique. The study group received concurrent fractionated cobalt 60 teletherapy using two opposing fields and 10-15 mg of Intra-arterial or Intravenous Bleomycin. The controls received fractionated cobalt teletherapy and i.v. or i.m. distilled water on the same protocol as the Bleomycin cases. All cases were evaluated double blind 8 weeks after the end of radiation therapy, and were classified as 'favourable response' or 'failure'. The criterion of 'favourable response' was 'total clinical healing of the tumour within the volume of irradiation with no subsequent recurrence within that volume, whatever the length of follow up'. Anything else was reported as a failure. A long term follow up of 3 years is also available. 136 cases have completed the trial. The favourable response in the study group was 77% as against 20.9% in the control group. The differential response is statistically significant. The present study is the fourth in the series of combined therapeutic trials conducted in advanced oral squamous cell carcinoma since 1958. (Krishnamurthi and Shanta, 1963, 1965, 1967 and 1971). A concurrent randomised controlled clinical trial to evaluate the combination of Bleomycin and radiation as against radiation only in treatment of advanced oral cancer has been conducted at the Cancer Institute, Madras since 1971.

Bleomycin↗
PubMed1982

Different iron(II) complexes of bleomycin A2.

By 13C-nmr on iron-bleomycin preparations, an iron-bleomycin-CO complex is found that loses its CO upon standing, as demonstrated using 14CO. Iron-bleomycin, prepared without rigorous exclusion of oxygen, reacts with CO to a stable diamagnetic iron-bleomycin-CO complex.

Bleomycin↗
PubMed1988

Therapeutic evaluation for intralesional injection of bleomycin sulfate in 143 resistant warts.

A 1 U/ml solution of bleomycin sulfate in physiologic saline solution was injected intralesionally in 38 patients, and was compared with physiologic saline solution injection into paired warts in the same patient. No patient received more than 2 ml of bleomycin. Ninety-seven of 143 warts (67.8%) showed complete resolution after one or two bleomycin injections, while 25 warts (17.5%) showed incomplete resolution. Bleomycin local injection failed to elicit any therapeutic response in 21 warts (14.7%). The cure rate was 77% for warts on the extremities, 71.4% for periungual warts, and 47.6% for the plantar warts. The responsive warts showed hemorrhagic eschars that healed without scarring. It is concluded that this form of treatment for resistant warts, up to the dose used, is safe, reliable, and accepted by the patient.

Adolescent↗
PubMed1996

Bleomycin-mediated electrochemotherapy of basal cell carcinoma.

BACKGROUND: A new technique, electroporation, enhances the antitumor effects of a variety of chemotherapeutic agents. When used in combination with conventional chemotherapy, the procedure is termed electrochemotherapy. Exposure of cancerous tissues to pulses of electricity during electrochemotherapy appears to increase cell membrane permeability and thus intracellular access to cytotoxic drugs. Electrochemotherapy has been shown to have potent antitumor activity in a variety of in vitro studies, animal tumor models, as well as in clinical trials with squamous cell carcinomas of the head and neck. OBJECTIVE: The purpose of the study was to determine the effects of bleomycin-mediated electrochemotherapy on several basal cell carcinomas (BCCs) in two patients with nevoid BCC syndrome. METHODS: Electrical pulses were delivered to tumor nodules by means of caliper electrodes after systemic doses of bleomycin were administered. Vital signs were closely monitored during application of the electrical pulses. RESULTS: Partial responses were observed in tumors from both of the patients treated with electrochemotherapy; three partial responses were observed in one patient, and one partial response was observed in the other patient. Complete responses were seen in two lesions. Only minimal local or systemic side effects were noted in response to the therapy. CONCLUSION: To our knowledge, this is the first study that documents the effects of bleomycin-mediated electrochemotherapy on BCC. Studies are ongoing with intralesional bleomycin during electrochemotherapy to see whether additional antitumour effects can be produced in patients with BCC by this route of administration.

Adult↗
PubMed2002

Comparative mutagenicities of bleomycin and ferric-nitrilotriacetate in lacZ mice.

Bleomycin and ferric nitrilotriacetate (Fe-NTA) give rise to reactive oxygen species (ROS). Bleomycin was mutagenic in lacZ mouse kidney, liver and lung, but Fe-NTA was non-mutagenic in kidney and lung and marginally mutagenic in liver. Fe-NTA-treatment led to an increase in 8-hydroxydeoxyguanosine levels in kidney and liver, while the corresponding levels in bleomycin-treated mice were if anything, lower than those for bleomycin. It appears that factors other than simply the ability to generate ROS, play a role in mutagenesis by these compounds.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

Folk medicine Terminalia catappa and its major tannin component, punicalagin, are effective against bleomycin-induced genotoxicity in Chinese hamster ovary cells.

Terminalia catappa L. is a popular folk medicine for preventing hepatoma and treating hepatitis in Taiwan. In this paper, we examined the protective effects of T. catappa leaf water extract (TCE) and its major tannin component, punicalagin, on bleomycin-induced genotoxicity in cultured Chinese hamster ovary cells. Pre-treatment with TCE or punicalagin prevented bleomycin-induced hgprt gene mutations and DNA strand breaks. TCE and punicalagin suppressed the generation of bleomycin-induced intracellular free radicals, identified as superoxides and hydrogen peroxides. The effectiveness of TCE and punicalagin against bleomycin-induced genotoxicity could be, at least in part, due to their antioxidative potentials.

Animals↗
PubMed2000

Bleomycin-induced chromosome aberrations in head and neck cancer patients analyzed by classical cytogenetics and FISH.

Individual sensitivity to mutagens has been considered to play an important role in head-and-neck squamous cells carcinoma (HNSCC) development. The bleomycin test was introduced for establishing constitutional susceptibility to mutagens (T.C. Hsu, D.A. Johnston, L.M. Cherry, D. Ramkisson, S.P. Schantz, J.M. Jessup, R.J. Winn, L. Shirley, C. Furlong, Sensitivity to genotoxic effects of bleomycin in humans: possible relationship to environmental carcinogenesis, Int. J. Cancer 43 (1989) 403-409). Its criteria are based on scoring of chromosome aberrations (CAs, mainly breaks) in Giemsa-stained chromosomes. Fluorescence in situ hybridization (FISH) offers an easy method for analysis of translocations, acentric fragments and dicentrics. In the present study FISH was applied in the analysis of bleomycin-induced CAs of the HNSCC patients and controls. The results proved that FISH is a complementary method to the classical staining in monitoring of bleomycin-induced CAs.

Adult↗
PubMed2003

Electrochemotherapy: results of cancer treatment using enhanced delivery of bleomycin by electroporation.

Over the last decade a new cancer treatment modality, electrochemotherapy, has emerged. By using short, intense electric pulses that surpass the capacitance of the cell membrane, permeabilization can occur (electroporation). Thus, molecules that are otherwise non-permeant can gain direct access to the cytosol of cells in the treated area.A highly toxic molecule that does not usually pass the membrane barrier is the hydrophilic drug bleomycin. Once inside the cell, bleomycin acts as an enzyme creating single- and double-strand DMA-breaks. The cytotoxicity of bleomycin can be augmented several 100-fold by electroporation. Drug delivery by electroporation has been in experimental use for cancer treatment since 1991. This article reviews 11 studies of electrochemotherapy of malignant cutaneous or subcutaneous lesions, e.g., metastases from melanoma, breast or head- and neck cancer. These studies encompass 96 patients with altogether 411 malignant tumours. Electroporation was performed using plate or needle electrodes under local or general anaesthesia. Bleomycin was administered intratumourally or intravenously prior to delivery of electric pulses. The rates of complete response (CR) after once-only treatments were between 9 and 100% depending on the technique used. The treatment was well tolerated and could be performed on an out-patient basis.

Antimetabolites, Antineoplastic↗
PubMed2003

Postoperative concomitant irradiation and chemotherapy with mitomycin C and bleomycin for advanced head-and-neck carcinoma.

PURPOSE: In a prospective randomized clinical study, simultaneous postoperative application of irradiation (RT), mitomycin C, and bleomycin was tested in a group of patients with operable advanced head-and-neck carcinoma. It was expected that the planned combined postoperative therapy would reduce the number of locoregional recurrences and prolong survival. METHODS AND MATERIALS: A total of 114 eligible patients with Stage III or IV squamous cell head-and-neck carcinoma were randomized to receive postoperative RT alone (Group 1) or RT combined with simultaneous mitomycin C and bleomycin (Group 2). Patients were stratified according to the stage and site of the primary tumor and the presence or absence of high-risk prognostic factors. Primary surgical treatment was performed with curative intent in all patients. Patients in both groups were postoperatively irradiated to the total dose of 56-70 Gy. Chemotherapy included mitomycin C 15 mg/m(2) after 10 Gy and 5 mg of bleomycin twice a week during RT to the planned total dose of 70 mg. RESULTS: At 2 years, patients in the radiochemotherapy group had better locoregional control (86%) than those in the RT alone group (69%; p = 0.037). Disease-free survival and overall survival was also better in the radiochemotherapy group compared with the RT-alone group (76% vs. 60%, p = 0.099; and 74% vs. 64%, p = 0.036, respectively). Patients who benefited from chemotherapy were those with high-risk factors. CONCLUSION: The results of the present study indicate that concomitant postoperative radiochemotherapy with mitomycin C and bleomycin improves locoregional control and survival in patients with advanced head-and-neck carcinoma. The patients who benefited from chemotherapy were those with high-risk factors.

Adult↗
PubMed2003

Enhanced bleomycin-induced pulmonary damage in mice lacking extracellular superoxide dismutase.

Extracellular superoxide dismutase (EC-SOD) is highly expressed in the extracellular matrix of lung and vascular tissue. Localization of EC-SOD to the matrix of the lung may protect against oxidative tissue damage that leads to pulmonary fibrosis. This study directly examines the protective role of EC-SOD in a bleomycin model of pulmonary fibrosis and the effect of this enzyme on oxidative protein fragmentation. Mice null for ec-sod display a marked increase in lung inflammation at 14 d post-bleomycin treatment as compared to their wild-type counterparts. Hydroxyproline analysis determined that both wild-type and ec-sod null mice display a marked increase in interstitial fibrosis at 14 d post-treatment, and the severity of fibrosis is significantly increased in ec-sod null mice compared to wild-type mice. To determine if the lack of EC-SOD promotes bleomycin-induced oxidative protein modification, 2-pyrrolidone content (as a measure of oxidative protein fragmentation at proline residues) was assessed in lung tissue from treated mice. 2-Pyrrolidone levels in the lung hydrolysates from ec-sod null mice were increased at both 7 and 14 d post-bleomycin treatment as compared to wild-type mice, indicating EC-SOD can inhibit oxidative fragmentation of proteins in this specific model of oxidative stress.

Animals↗